me2402 mechatronics lecture notes

7/22/2019 ME2402 Mechatronics Lecture Notes

1/108

Einstein College of Engineering

Unit 1

Introduction to Mechatronics Systems

Mechatronicsis thesynergistic combination ofMechanical engineering,Electronic

engineering,Computer engineering,Control engineering,andSystems Design engineering in orderto design, and manufacture useful products. The term mechatronics is defined as amultidisciplinary

engineering system design, that is to say it rejects splittingengineering into separate disciplines.

A mechatronics engineer unites the principles of mechanics, electronics, and computing to

generate a simpler, more economical and reliable system. Mechatronics is centered onmechanics,

electronics,computing,control engineering,molecular engineering (fromnanochemistry and

biology), andoptical engineering,which, combined, make possible the generation of simpler, more

economical, reliable and versatile systems. The portmanteau "mechatronics" was coined by Tetsuro

Mori, the senior engineer of theJapanese companyYaskawa in 1969. Anindustrial robot is a prime

example of a mechatronics system; it includes aspects of electronics, mechanics, and computing to

do its day-to-day jobs.

The development of mechatronics has gone through three stages: The first stage corresponds

to the years around the introduction of word mechatronics.

During this stage, technologies used in mechatronics systems developed rather independently of

each other and individually.With start of eighties a synergic integration of different technologies

started taking place.A notable example is opto-electronics, an integration of optics and electronics.

The concept of hardware/software co-design also started in this year.

The third stage, which is considered as start of Mechatronics Age, starts with the earlynineties. The most notable aspect of this stage are more and more integration of different engineering

disciplinesand increased use of computational intelligence in the mechatronics products andsystems.Another important development in the third stage is the concept of micromechatronis, i.e.,

start of miniaturization the components such as microactuators and microsensors.Design of such

products and processes, therefore, has to be the outcome of a multi-disciplinary act ivity rather than

an interdisciplinary one.

Hence mechatronics challenges the traditional engineering thinking, because the way it is operating,

is crossing the boundaries between the traditional engineering disciplines.

SENSORS

A sensor is a device which receives and responds to a signal. A sensor's sensitivity indicates

how much the sensor's output changes when the measured quantity changes. For instance, if the

mercury in a thermometer moves 1 cm when the temperature changes by 1 C, the sensitivity is
http://en.wikipedia.org/wiki/Synergistichttp://en.wikipedia.org/wiki/Mechanical_engineeringhttp://en.wikipedia.org/wiki/Electronic_engineeringhttp://en.wikipedia.org/wiki/Electronic_engineeringhttp://en.wikipedia.org/wiki/Computer_engineeringhttp://en.wikipedia.org/wiki/Control_engineeringhttp://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/Multidisciplinaryhttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Mechanicshttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Computinghttp://en.wikipedia.org/wiki/Control_engineeringhttp://en.wikipedia.org/wiki/Molecular_engineeringhttp://en.wikipedia.org/wiki/Nanochemistryhttp://en.wikipedia.org/wiki/Biologyhttp://en.wikipedia.org/wiki/Optical_engineeringhttp://en.wikipedia.org/wiki/Economy_of_Japanhttp://en.wikipedia.org/wiki/Yaskawahttp://en.wikipedia.org/wiki/Industrial_robothttp://en.wikipedia.org/wiki/Industrial_robothttp://en.wikipedia.org/wiki/Yaskawahttp://en.wikipedia.org/wiki/Economy_of_Japanhttp://en.wikipedia.org/wiki/Optical_engineeringhttp://en.wikipedia.org/wiki/Biologyhttp://en.wikipedia.org/wiki/Nanochemistryhttp://en.wikipedia.org/wiki/Molecular_engineeringhttp://en.wikipedia.org/wiki/Control_engineeringhttp://en.wikipedia.org/wiki/Computinghttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Mechanicshttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Multidisciplinaryhttp://en.wikipedia.org/wiki/Systems_engineeringhttp://en.wikipedia.org/wiki/Control_engineeringhttp://en.wikipedia.org/wiki/Computer_engineeringhttp://en.wikipedia.org/wiki/Electronic_engineeringhttp://en.wikipedia.org/wiki/Electronic_engineeringhttp://en.wikipedia.org/wiki/Electronic_engineeringhttp://en.wikipedia.org/wiki/Mechanical_engineeringhttp://en.wikipedia.org/wiki/Synergistic


2/108


1 cm/C (it is basically the slope Dy/Dx assuming a linear characteristic). Sensors that measure very

small changes must have very high sensitivities.

A good sensor obeys the following rules:

Is sensitive to the measured property Is insensitive to any other property likely to be encountered in its application Does not influence the measured propertyCharacteristics of sensor

Thesensitivitymay in practice differ from the value specified. This is called a sensitivityerror, but the sensor is still linear.

Since the range of the output signal is always limited, the output signal will eventually reacha minimum or maximum when the measured property exceeds the limits. The full scale range

defines the maximum and minimum values of the measured property. If the output signal is not zero when the measured property is zero, the sensor has anoffsetor

bias.This is defined as the output of the sensor at zero input.

If the sensitivity is not constant over the range of the sensor, this is callednonlinearity.Usually this is defined by the amount the output differs from ideal behavior over the full

range of the sensor, often noted as a percentage of the full range.

If the deviation is caused by a rapid change of the measured property over time, there is adynamicerror. Often, this behaviour is described with abode plotshowing sensitivity error

and phase shift as function of the frequency of a periodic input signal.

If the output signal slowly changes independent of the measured property, this is defined asdrift (telecommunication).

Long term driftusually indicates a slow degradation of sensor properties over a long periodof time.

Noiseis a random deviation of the signal that varies in time. Hysteresisis an error caused by when the measured property reverses direction, but there is

some finite lag in time for the sensor to respond, creating a different offset error in onedirection than in the other.

If the sensor has a digital output, the output is essentially an approximation of the measuredproperty. The approximation error is also calleddigitizationerror.

If the signal is monitored digitally, limitation of thesampling frequencyalso can cause adynamic error, or if the variable or added noise noise changes periodically at a frequency

near a multiple of the sampling rate may inducealiasingerrors. The sensor may to some extent be sensitive to properties other than the property being

measured. For example, most sensors are influenced by the temperature of their environment.

DISPLACEMENT AND POSITION SENSORS

Displacement Measurement

Measurement of displacement is the basis of measuring:

Position

VelocityAcceleration

StressForce
http://en.wikipedia.org/wiki/Sensitivity_%28electronics%29http://en.wikipedia.org/wiki/Sensitivity_%28electronics%29http://en.wikipedia.org/wiki/Sensitivity_%28electronics%29http://en.wikipedia.org/wiki/Offsethttp://en.wikipedia.org/wiki/Offsethttp://en.wikipedia.org/wiki/Offsethttp://en.wikipedia.org/wiki/Biashttp://en.wikipedia.org/wiki/Biashttp://en.wikipedia.org/wiki/Nonlinearityhttp://en.wikipedia.org/wiki/Nonlinearityhttp://en.wikipedia.org/wiki/Nonlinearityhttp://en.wikipedia.org/wiki/Dynamics_%28physics%29http://en.wikipedia.org/wiki/Dynamics_%28physics%29http://en.wikipedia.org/wiki/Bode_plothttp://en.wikipedia.org/wiki/Bode_plothttp://en.wikipedia.org/wiki/Bode_plothttp://en.wikipedia.org/wiki/Drift_%28telecommunication%29http://en.wikipedia.org/wiki/Drift_%28telecommunication%29http://en.wikipedia.org/w/index.php?title=Long_term_drift&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Long_term_drift&action=edit&redlink=1http://en.wikipedia.org/wiki/Noisehttp://en.wikipedia.org/wiki/Noisehttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Digitizationhttp://en.wikipedia.org/wiki/Digitizationhttp://en.wikipedia.org/wiki/Digitizationhttp://en.wikipedia.org/wiki/Sampling_frequencyhttp://en.wikipedia.org/wiki/Sampling_frequencyhttp://en.wikipedia.org/wiki/Sampling_frequencyhttp://en.wikipedia.org/wiki/Aliasinghttp://en.wikipedia.org/wiki/Aliasinghttp://en.wikipedia.org/wiki/Aliasinghttp://en.wikipedia.org/wiki/Aliasinghttp://en.wikipedia.org/wiki/Sampling_frequencyhttp://en.wikipedia.org/wiki/Digitizationhttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Noisehttp://en.wikipedia.org/w/index.php?title=Long_term_drift&action=edit&redlink=1http://en.wikipedia.org/wiki/Drift_%28telecommunication%29http://en.wikipedia.org/wiki/Bode_plothttp://en.wikipedia.org/wiki/Dynamics_%28physics%29http://en.wikipedia.org/wiki/Nonlinearityhttp://en.wikipedia.org/wiki/Biashttp://en.wikipedia.org/wiki/Offsethttp://en.wikipedia.org/wiki/Sensitivity_%28electronics%29


3/108


Pressure

Proximity

Thickness

Displacement Sensors types

Potentiometers displacement sensors Inductive displacement sensors Capacitive displacement sensors Eddy current displacement sensors Piezoelectric displacement sensors Ultrasonic displacement sensors Magnetostrictive displacement sensors Optical encoder displacement sensors Strain Gages displacement sensors

Resistive displacement sensors: An electrically conductive wiper that slides against a fixed

resistive element. To measure displacement, a potentiometer is typically wired in a voltage divider

configuration.

A known voltage is applied to the resistor ends. The contact is attached to the moving

object of interest The output voltage at the contact is proportional to the displacement.


4/108


Inductive displacement sensorsThe coil acts as a source of magnetomotive force that drives the flux through the magnetic

circuit and the air gap. The presence of the air gap causes a large increase in circuit reluctance and a

corresponding decrease in the flux. Hence, a small variation in the air gap results in a

measurable change in inductance.

Linear Variable Differential Transformer (LVDT)Motion of a magnetic core changes the mutual inductance of two secondary coils relative to a

primary coil Primary coil voltage: VSsin(wt)

Secondary coil induced emf:

V1=k1sin(wt) and V2=k2sin(wt)

k1 and k2 depend on the amount of coupling between the primary and the secondary coils,which is proportional to the position of the coil.When the coil is in the central position,

k1=k2; VOUT=V1-V2=0When the coil is is displaced x units,

k1 not equal to k2 ;

VOUT=(k1-k2)sin(wt)

Positive or negative displacements are determined from the phase

of VOUT.


5/108



6/108



7/108



8/108


The linear variable differential transformer(LVDT) is a type of electricaltransformerused for

measuring linear displacement. The transformer has threesolenoidalcoils placed end-to-end around

a tube. The center coil is the primary, and the two outer coils are the secondaries. A cylindrical

ferromagnetic core, attached to the object whose position is to be measured, slides along the axis of

the tube.

Analternating currentis driven through the primary, causing avoltageto be induced in each

secondary proportional to its mutualinductancewith the primary. Thefrequencyis usually in the

range 1 to 10kHz.

As the core moves, these mutual inductances change, causing the voltages induced in the secondaries

to change. The coils are connected in reverse series, so that the output voltage is the difference(hence "differential") between the two secondary voltages. When the core is in its central position,
http://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Transformerhttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Potential_differencehttp://en.wikipedia.org/wiki/Potential_differencehttp://en.wikipedia.org/wiki/Potential_differencehttp://en.wikipedia.org/wiki/Inductancehttp://en.wikipedia.org/wiki/Inductancehttp://en.wikipedia.org/wiki/Inductancehttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Kilohertzhttp://en.wikipedia.org/wiki/Kilohertzhttp://en.wikipedia.org/wiki/Kilohertzhttp://en.wikipedia.org/wiki/Kilohertzhttp://en.wikipedia.org/wiki/Frequencyhttp://en.wikipedia.org/wiki/Inductancehttp://en.wikipedia.org/wiki/Potential_differencehttp://en.wikipedia.org/wiki/Alternating_currenthttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Transformer


9/108


equidistant between the two secondaries, equal but opposite voltages are induced in these two coils,

so the output voltage is zero.

When the core is displaced in one direction, the voltage in one coil increases as the other decreases,

causing the output voltage to increase from zero to a maximum. This voltage is inphasewith the

primary voltage. When the core moves in the other direction, the output voltage also increases fromzero to a maximum, but its phase is opposite to that of the primary. The magnitude of the output

voltage is proportional to the distance moved by the core (up to its limit of travel), which is why the

device is described as "linear". The phase of the voltage indicates the direction of the displacement.

Because the sliding core does not touch the inside of the tube, it can move without friction, makingthe LVDT a highly reliable device. The absence of any sliding or rotating contacts allows the LVDT

to be completely sealed against the environment.

LVDTs are commonly used for position feedback inservomechanisms,and for automated

measurement in machine tools and many ot her industrial and scientific applications.

A proximity sensoris asensorable to detect the presence of nearby objects without any physical

contact. A proximity sensor often emits anelectromagneticorelectrostaticfield, or a beam of

electromagnetic radiation(infrared,for instance), and looks for changes in thefieldor return signal.

The object being sensed is often referred to as the proximity sensor's target. Different proximity

sensor targets demand different sensors. For example, acapacitiveorphotoelectric sensormight be

suitable for a plastic target; aninductiveproximity sensor requires a metal target.

The maximum distance that this sensor can detect is defined "nominal range". Some sensors haveadjustments of the nominal range or means to report a graduated detection distance.

Proximity sensors can have a high reliability and long functional life because of the absence of

mechanical parts and lack of physical contact between sensor and the sensed object.

Proximity sensors are also used in machine vibration monitoring to measure the variation in distance

between a shaft and its support bearing. This is common in large steam turbines, compressors, andmotors that use sleeve-type bearings.
http://en.wikipedia.org/wiki/Phase_%28waves%29http://en.wikipedia.org/wiki/Phase_%28waves%29http://en.wikipedia.org/wiki/Phase_%28waves%29http://en.wikipedia.org/wiki/Servomechanismhttp://en.wikipedia.org/wiki/Servomechanismhttp://en.wikipedia.org/wiki/Servomechanismhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Electrostatichttp://en.wikipedia.org/wiki/Electrostatichttp://en.wikipedia.org/wiki/Electrostatichttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Capacitive_proximity_sensorhttp://en.wikipedia.org/wiki/Capacitive_proximity_sensorhttp://en.wikipedia.org/wiki/Capacitive_proximity_sensorhttp://en.wikipedia.org/wiki/Photoelectric_sensorhttp://en.wikipedia.org/wiki/Photoelectric_sensorhttp://en.wikipedia.org/wiki/Photoelectric_sensorhttp://en.wikipedia.org/wiki/Inductive_sensorhttp://en.wikipedia.org/wiki/Inductive_sensorhttp://en.wikipedia.org/wiki/Inductive_sensorhttp://en.wikipedia.org/wiki/Inductive_sensorhttp://en.wikipedia.org/wiki/Photoelectric_sensorhttp://en.wikipedia.org/wiki/Capacitive_proximity_sensorhttp://en.wikipedia.org/wiki/Electric_fieldhttp://en.wikipedia.org/wiki/Infraredhttp://en.wikipedia.org/wiki/Electromagnetic_radiationhttp://en.wikipedia.org/wiki/Electrostatichttp://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Servomechanismhttp://en.wikipedia.org/wiki/Phase_%28waves%29


10/108


A thermocoupleis a junction between two different metals that produces avoltagerelated to a

temperaturedifference. Thermocouples are a widely used type oftemperature sensorfor

measurement and control[1]and can also be used to convert heat into electric power. They are

inexpensive[2]

and interchangeable, are supplied fitted with standard connectors, and can measure a

wide range of temperatures. The main limitation is accuracy: system errors of less than one degree

Celsius(C) can be difficult to achieve.[3]

Any junction of dissimilar metals will produce an electric potential related to temperature.

Thermocouples for practical measurement of temperature are junctions of specificalloyswhich have

a predictable and repeatable relationship between temperature and voltage. Different alloys are used

for different temperature ranges. Properties such as resistance to corrosion may also be importantwhen choosing a type of thermocouple. Where the measurement point is far from the measuring

instrument, the intermediate connection can be made by extension wires which are less costly than

the materials used to make the sensor. Thermocouples are usually standardized against a reference

temperature of 0 degrees Celsius; practical instruments use electronic methods of cold-junction

compensation to adjust for varying temperature at the instrument terminals. Electronic instruments

can also compensate for the varying characteristics of the thermocouple, and so improve theprecision and accuracy of measurements.

Thermocouples are widely used in science and industry; applications include temperature

measurement forkilns,gas turbineexhaust,dieselengines, and other industrial processes.

Resistance thermometers, also called resistance temperature detectorsor resistive thermal

devices(RTDs), aretemperaturesensorsthat exploit the predictable change inelectrical resistance

of some materials with changing temperature. As they are almost invariably made ofplatinum,they

are often called platinum resistance thermometers(PRTs). They are slowly replacing the use of

thermocouplesin many industrial applications below 600 C,due to higher accuracy and

repeatability.[1]

There are many categories; carbon resistors, film, and wire-wound types are the most widely used.

Carbon resistorsare widely available and are very inexpensive. They have very reproducibleresults at low temperatures. They are the most reliable form at extremely low temperatures.

They generally do not suffer from significanthysteresisor strain gauge effects. Carbon

resistors have been used for many years because of their advantages.

Film thermometershave a layer of platinum on asubstrate;the layer may be extremely thin,perhaps onemicrometer.Advantages of this type are relatively low cost (the high cost ofplatinum being offset by the tiny amount required) and fast response. Such devices haveimproved performance although the different expansion rates of the substrate and platinum

give "strain gauge"effects and stability problems.

Wire-wound thermometerscan have greater accuracy, especially for wide temperature ranges. The

coil diameter provides a compromise between mechanical stability and allowing expansion of the

wire to minimize strain and consequential drift.
http://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/List_of_temperature_sensorshttp://en.wikipedia.org/wiki/List_of_temperature_sensorshttp://en.wikipedia.org/wiki/List_of_temperature_sensorshttp://en.wikipedia.org/wiki/Thermocouple#cite_note-tcs_html-0http://en.wikipedia.org/wiki/Thermocouple#cite_note-tcs_html-0http://en.wikipedia.org/wiki/Thermocouple#cite_note-tcs_html-0http://en.wikipedia.org/wiki/Thermocouple#cite_note-Ramsden2000-1http://en.wikipedia.org/wiki/Thermocouple#cite_note-Ramsden2000-1http://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Thermocouple#cite_note-tctable.html-2http://en.wikipedia.org/wiki/Thermocouple#cite_note-tctable.html-2http://en.wikipedia.org/wiki/Thermocouple#cite_note-tctable.html-2http://en.wikipedia.org/wiki/Alloyhttp://en.wikipedia.org/wiki/Alloyhttp://en.wikipedia.org/wiki/Alloyhttp://en.wikipedia.org/wiki/Kilnhttp://en.wikipedia.org/wiki/Kilnhttp://en.wikipedia.org/wiki/Kilnhttp://en.wikipedia.org/wiki/Gas_turbinehttp://en.wikipedia.org/wiki/Gas_turbinehttp://en.wikipedia.org/wiki/Gas_turbinehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Platinumhttp://en.wikipedia.org/wiki/Platinumhttp://en.wikipedia.org/wiki/Platinumhttp://en.wikipedia.org/wiki/Thermocouplehttp://en.wikipedia.org/wiki/Thermocouplehttp://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Resistance_thermometer#cite_note-0http://en.wikipedia.org/wiki/Resistance_thermometer#cite_note-0http://en.wikipedia.org/wiki/Resistance_thermometer#cite_note-0http://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Platinghttp://en.wikipedia.org/wiki/Platinghttp://en.wikipedia.org/wiki/Platinghttp://en.wikipedia.org/wiki/Merehttp://en.wikipedia.org/wiki/Merehttp://en.wikipedia.org/wiki/Merehttp://en.wikipedia.org/wiki/Strain_gaugehttp://en.wikipedia.org/wiki/Strain_gaugehttp://en.wikipedia.org/wiki/Strain_gaugehttp://en.wikipedia.org/wiki/Strain_gaugehttp://en.wikipedia.org/wiki/Merehttp://en.wikipedia.org/wiki/Platinghttp://en.wikipedia.org/wiki/Hysteresishttp://en.wikipedia.org/wiki/Resistance_thermometer#cite_note-0http://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Thermocouplehttp://en.wikipedia.org/wiki/Platinumhttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Sensorhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Gas_turbinehttp://en.wikipedia.org/wiki/Kilnhttp://en.wikipedia.org/wiki/Alloyhttp://en.wikipedia.org/wiki/Thermocouple#cite_note-tctable.html-2http://en.wikipedia.org/wiki/Celsiushttp://en.wikipedia.org/wiki/Thermocouple#cite_note-Ramsden2000-1http://en.wikipedia.org/wiki/Thermocouple#cite_note-tcs_html-0http://en.wikipedia.org/wiki/List_of_temperature_sensorshttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Voltage


11/108


ME1402 MECHATRONICS

(Common to Mechanical and Production- VI Semester)

OBJECTIVE

To understand the interdisciplinary applications of Electronics, Electrical, Mechanical and

Computer Systems for the Control of Mechanical and Electronic Systems.

1.MECHATRONICS, SENSORS AND TRANSDUCERS 9

Introduction to Mechatronics SystemsMeasurement SystemsControl SystemsMicroprocessorbased Controllers. Sensors and TransducersPerformance TerminologySensors for

Displacement, Position and Proximity; Velocity, Motion, Force, Fluid Pressure, Liquid Flow, Liquid

Level, Temperature, Light SensorsSelection of Sensors

2.ACTUATION SYSTEMS 9

Pneumatic and Hydraulic SystemsDirectional Control ValvesRotary Actuators. Mechanical

Actuation SystemsCamsGear TrainsRatchet and pawlBelt and Chain DrivesBearings.

Electrical Actuation SystemsMechanical SwitchesSolid State SwitchesSolenoidsD.CMotorsA.C MotorsStepper Motors.

3.SYSTEM MODELS AND CONTROLLERS 9

Building blocks of Mechanical, Electrical, Fluid and Thermal Systems, RotationalTransnationalSystems, Electromechanical SystemsHydraulicMechanical Systems. Continuous and discrete

process ControllersControl ModeTwoStep modeProportional ModeDerivative Mode

Integral ModePID ControllersDigital ControllersVelocity ControlAdaptive Control

Digital Logic ControlMicro Processors Control.

4. PROGRAMMING LOGIC CONTROLLERS 9

Programmable Logic ControllersBasic StructureInput / Output ProcessingProgramming

MnemonicsTimers, Internal relays and countersShift RegistersMaster and Jump ControlsData HandlingAnalogs Input / OutputSelection of a PLC Problem.

5.DESIGN OF MECHATRONICS SYSTEM 9

Stages in designing Mechatronics SystemsTraditional and Mechatronic Design - Possible Design

Solutions Case Studies of Mechatronics Systems, Pick and place robotautomatic Car Park

SystemsEngine Management Systems.

TOTAL : 45

TEXT BOOKSW. Bolton, Mechatronics, Pearson Education, Second Edition, 1999.

REFERENCES

Michael B. Histand and David G. Alciatore, Introduction to Mechatronics and Measurement

Systems, McGraw-Hill International Editions, 2000.

Bradley D. A., Dawson D., Buru N.C. and. Loader A.J, Mechatronics, Chapman and Hall, 1993.

Dan Necsulesu, Mechatronics, Pearson Education Asia, 2002 (Indian Reprint).

Lawrence J. Kamm, Understanding Electro Mechanical Engineering, An Introduction to

Mechatronics, PrenticeHall of India Pvt., Ltd., 2000.

Nitaigour Premchand Mahadik, Mechatronics, Tata McGraw-Hill publishing Company Ltd, 2003


12/108


Unit 1

Unit 2 ACTUATION SYSTEMS

Pneumatic and Hydraulic SystemsDirectional Control ValvesRotary Actuators. Mechanical

Actuation SystemsCamsGear TrainsRatchet and pawlBelt and Chain DrivesBearings.Electrical Actuation SystemsMechanical SwitchesSolid State SwitchesSolenoidsD.C

MotorsA.C MotorsStepper Motors.

Pneumatic systems

Pneumaticsis a branch of technology, which deals with the study and application of use ofpressurized gas to affect mechanical motion.

Pneumatic systems are extensively used inindustry,wherefactories are commonly plumbed with

compressed air or other compressedinert gases.This is because a centrally-located and electrically-

poweredcompressor that powerscylinders and other pneumatic devices throughsolenoid valves is

often able to provide motive power in a cheaper, safer, more flexible, and more reliable way than a

large number ofelectric motors andactuators.

Pneumatics also has applications indentistry,construction,mining,and other areas.

Gases used in pneumatic systems

Pneumatic systems in fixed installations such as factories use compressed air because a sustainable

supply can be made by compressing atmospheric air. The air usually has moisture removed and a

small quantity of oil added at the compressor, to avoid corrosion of mechanical components and to

lubricate them.

Factory-plumbed, pneumatic-power users need not worry about poisonous leakages as the gas is

commonly just air. Smaller or stand-alone systems can use other compressed gases which are an

asphyxiationhazard, such asnitrogen- often referred to asOFN (oxygen-free nitrogen),when

supplied in cylinders.

Any compressed gas other than air is an asphyxiation hazard - including nitrogen, which makes up

approximately 80% of air. Compressedoxygen(approx. 20% of air) would not asphyxiate, but itwould be an extreme fire hazard, so is never used in pneumatically powered devices.

Portable pneumatic tools and small vehicles such asRobot Warsmachines and other hobbyistapplications are often powered by compressedcarbon dioxidebecause containers designed to hold it

such assoda streamcanisters and fire extinguishers are readily available, and thephase changebetween liquid and gas makes it possible to obtain a larger volume of compressed gas from a lighter

container than compressed air would allow. Carbon dioxide is an asphyxiant and can also be afreezing hazard when vented inappropriately.

Advantages of pneumatics

Simplicity of Design And Control
http://en.wikipedia.org/wiki/Pressurized_gashttp://en.wikipedia.org/wiki/Industryhttp://en.wikipedia.org/wiki/Factoryhttp://en.wikipedia.org/wiki/Compressed_airhttp://en.wikipedia.org/wiki/Inert_gaseshttp://en.wikipedia.org/wiki/Gas_compressorhttp://en.wikipedia.org/wiki/Pneumatic_cylinderhttp://en.wikipedia.org/wiki/Solenoid_valvehttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Dentistryhttp://en.wikipedia.org/wiki/Constructionhttp://en.wikipedia.org/wiki/Mininghttp://en.wikipedia.org/wiki/Asphyxiationhttp://en.wikipedia.org/wiki/Asphyxiationhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Nitrogen#Applicationshttp://en.wikipedia.org/wiki/Nitrogen#Applicationshttp://en.wikipedia.org/wiki/Nitrogen#Applicationshttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Robot_Wars_%28TV_series%29http://en.wikipedia.org/wiki/Robot_Wars_%28TV_series%29http://en.wikipedia.org/wiki/Robot_Wars_%28TV_series%29http://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Soda_streamhttp://en.wikipedia.org/wiki/Soda_streamhttp://en.wikipedia.org/wiki/Soda_streamhttp://en.wikipedia.org/wiki/Carbon_dioxide#Useshttp://en.wikipedia.org/wiki/Carbon_dioxide#Useshttp://en.wikipedia.org/wiki/Carbon_dioxide#Useshttp://en.wikipedia.org/wiki/Carbon_dioxide#Useshttp://en.wikipedia.org/wiki/Soda_streamhttp://en.wikipedia.org/wiki/Carbon_dioxidehttp://en.wikipedia.org/wiki/Robot_Wars_%28TV_series%29http://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Nitrogen#Applicationshttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Asphyxiationhttp://en.wikipedia.org/wiki/Mininghttp://en.wikipedia.org/wiki/Constructionhttp://en.wikipedia.org/wiki/Dentistryhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Solenoid_valvehttp://en.wikipedia.org/wiki/Pneumatic_cylinderhttp://en.wikipedia.org/wiki/Gas_compressorhttp://en.wikipedia.org/wiki/Inert_gaseshttp://en.wikipedia.org/wiki/Compressed_airhttp://en.wikipedia.org/wiki/Factoryhttp://en.wikipedia.org/wiki/Industryhttp://en.wikipedia.org/wiki/Pressurized_gas


13/108


o Machines are easily designed using standard cylinders & other components. Controlis as easy as it is simple ON - OFF type control.

Reliabilityo Pneumatic systems tend to have long operating lives and require very little

maintenance.

o Because gas is compressible, the equipment is less likely to be damaged by shock.The gas in pneumatics absorbs excessive force, whereas the fluid of hydraulics

directly transfers force.

Storageo Compressed Gas can be stored, allowing the use of machines when electrical power is

lost.

Safetyo Very low chance of fire (compared to hydraulic oil).o Machines can be designed to be overload safe.

Hydraulic systems

Hydraulic machineryare machines and tools which usefluid powerto do simple work.Heavy

equipmentis a common example.

In this type of machine, high-pressureliquidcalledhydraulic fluidis transmitted throughoutthe machine to varioushydraulic motorsandhydraulic cylinders.The fluid is controlled directly or

automatically bycontrol valvesand distributed throughhosesandtubes.

The popularity of hydraulic machinery is due to the very large amount of power that can be

transferred through small tubes and flexible hoses, and the high power density and wide array of

actuatorsthat can make use of this power.

Hydraulic machinery is operated by the use of hydraulics, where a liquid is the powering medium

Advantages of hydraulics

Liquid (as a gas is also a 'fluid') does not absorb any of the supplied energy. Capable of moving much higher loads and providing much higher forces due to the

incompressibility.
http://en.wikipedia.org/wiki/Fluid_powerhttp://en.wikipedia.org/wiki/Fluid_powerhttp://en.wikipedia.org/wiki/Fluid_powerhttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Hydraulic_fluidhttp://en.wikipedia.org/wiki/Hydraulic_fluidhttp://en.wikipedia.org/wiki/Hydraulic_fluidhttp://en.wikipedia.org/wiki/Hydraulic_motorhttp://en.wikipedia.org/wiki/Hydraulic_motorhttp://en.wikipedia.org/wiki/Hydraulic_motorhttp://en.wikipedia.org/wiki/Hydraulic_cylinderhttp://en.wikipedia.org/wiki/Hydraulic_cylinderhttp://en.wikipedia.org/wiki/Hydraulic_cylinderhttp://en.wikipedia.org/wiki/Control_valveshttp://en.wikipedia.org/wiki/Control_valveshttp://en.wikipedia.org/wiki/Control_valveshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Hydraulic_machinery#Hose.2C_tubes_and_pipeshttp://en.wikipedia.org/wiki/Control_valveshttp://en.wikipedia.org/wiki/Hydraulic_cylinderhttp://en.wikipedia.org/wiki/Hydraulic_motorhttp://en.wikipedia.org/wiki/Hydraulic_fluidhttp://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Engineering_vehiclehttp://en.wikipedia.org/wiki/Fluid_power


14/108


The hydraulic working fluid is basically incompressible, leading to a minimum ofspringaction. When hydraulic fluid flow is stopped, the slightest motion of the load releases the

pressure on the load; there is no need to "bleed off" pressurized air to release the pressure on

the load.

Directional control valvesare one of the most fundamental parts inhydraulic machinery.Theyallow fluid flow into different paths from one or more sources. They usually consist of apiston

inside a cylinder which is electrically controlled. The movement of the cylinder restricts or permits

the flow, thus it controls the fluid flow.

Directional control valves are mainly two types:

Hydraulic and Pneumatic.

Hydraulic directional control valves are for a liquid working fluid (e.g. water,hydraulic oil)and

pneumatic directional control valves are for a gaseous (usually air) working fluid.

Control valves

Directional control valvesroute the fluid to the desired actuator. They usually consist of a spool

inside acast ironorsteelhousing. The spool slides to different positions in the housing, intersectinggrooves and channels route the fluid based on the spool's position.

The spool has a central (neutral) position maintained with springs; in this position the supply fluid is

blocked, or returned to tank. Sliding the spool to one side routes the hydraulic fluid to an actuator

and provides a return path from the actuator to tank. When the spool is moved to the oppositedirection the supply and return paths are switched. When the spool is allowed to return to neutral

(center) position the actuator fluid paths are blocked, locking it in position.

Directional control valves are usually designed to be stackable, with one valve for each hydrauliccylinder, and one fluid input supplying all the valves in the stack.

Tolerances are very tight in order to handle the high pressure and avoid leaking, spools typically

have aclearancewith the housing of less than a thousandth of an inch (25 m). The valve block will

be mounted to the machine's frame with a three pointpattern to avoid distorting the valve block and

jamming the valve's sensitive components.

The spool position may be actuated by mechanical levers, hydraulicpilotpressure, orsolenoids

which push the spool left or right. Asealallows part of the spool to protrude outside the housing,

where it is accessible to the actuator.

The main valve block is usually a stack of off the shelfdirectional control valves chosen by flow

capacity and performance. Some valves are designed to be proportional (flow rate proportional to

valve position), while others may be simply on-off. The control valve is one of the most expensive

and sensitive parts of a hydraulic circuit.

Pressure relief valvesare used in several places in hydraulic machinery; on the return circuitto maintain a small amount of pressure for brakes, pilot lines, etc... On hydraulic cylinders, to
http://en.wikipedia.org/wiki/Spring_%28device%29http://en.wikipedia.org/wiki/Spring_%28device%29http://en.wikipedia.org/wiki/Spring_%28device%29http://en.wikipedia.org/wiki/Hydraulic_machineryhttp://en.wikipedia.org/wiki/Pistonhttp://en.wikipedia.org/wiki/Hydraulic_fluidhttp://en.wikipedia.org/wiki/Directional_control_valvehttp://en.wikipedia.org/wiki/Directional_control_valvehttp://en.wikipedia.org/wiki/Ironhttp://en.wikipedia.org/wiki/Ironhttp://en.wikipedia.org/wiki/Ironhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Hydraulic_clearancehttp://en.wikipedia.org/wiki/Hydraulic_clearancehttp://en.wikipedia.org/wiki/Hydraulic_clearancehttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Sealhttp://en.wikipedia.org/wiki/Sealhttp://en.wikipedia.org/wiki/Sealhttp://en.wikipedia.org/wiki/Pressure_relief_valvehttp://en.wikipedia.org/wiki/Pressure_relief_valvehttp://en.wikipedia.org/wiki/Pressure_relief_valvehttp://en.wikipedia.org/wiki/Sealhttp://en.wikipedia.org/wiki/Solenoidhttp://en.wikipedia.org/wiki/Hydraulic_clearancehttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Ironhttp://en.wikipedia.org/wiki/Directional_control_valvehttp://en.wikipedia.org/wiki/Hydraulic_fluidhttp://en.wikipedia.org/wiki/Pistonhttp://en.wikipedia.org/wiki/Hydraulic_machineryhttp://en.wikipedia.org/wiki/Spring_%28device%29


15/108


prevent overloading and hydraulic line/seal rupture. On the hydraulic reservoir, to maintain a

small positive pressure which excludes moisture and contamination.

Pressure regulatorsreduce the supply pressure of hydraulic fluids as needed for variouscircuits.

Sequence valvescontrol the sequence of hydraulic circuits; to ensure that one hydrauliccylinder is fully extended before another starts its stroke, for example.

Shuttle valvesprovide a logicalorfunction. Check valvesare one-way valves, allowing an accumulator to charge and maintain its

pressure after the machine is turned off, for example.

Pilot controlled Check valvesare one-way valve that can be opened (for both directions) bya foreign pressure signal. For instance if the load should not be hold by the check valve

anymore. Often the foreign pressure comes from the other pipe that is connected to the motor

or cylinder.

Counterbalance valvesare in fact a special type of pilot controlled check valve. Whereasthe check valve is open or closed, the counterbalance valve acts a bit like a pilot controlled

flow control.

Cartridge valvesare in fact the inner part of a check valve; they are off the shelfcomponentswith a standardized envelope, making them easy to populate a proprietary valve block. They

are available in many configurations; on/off, proportional, pressure relief, etc. They generallyscrew into a valve block and are electrically controlled to provide logic and automated

functions.

Hydraulic fusesare in-line safety devices designed to automatically seal off a hydraulic lineif pressure becomes too low, or safely vent fluid if pressure becomes too high.

Auxiliary valvesin complex hydraulic systems may have auxiliary valve blocks to handlevarious duties unseen to the operator, such as accumulator charging, cooling fan operation,

air conditioning power, etc. They are usually custom valves designed for the particular

machine, and may consist of a metal block with ports and channels drilled. Cartridge valves

are threaded into the ports and may be electrically controlled by switches or a microprocessor

to route fluid power as needed.

Hydraulic rotary actuators

The hydraulic rotary actuator is a device which transform hydraulic power (pressure and flow) in

rotational mechanical power (torque and speed).

It is used for alternative movements with a limited rotation angle (max 280).The simplicity of

construction allows to obtain very high mechanical efficiency values, close to 95%.

Mechanical actuation systems
http://en.wikipedia.org/wiki/Pressure_regulatorhttp://en.wikipedia.org/wiki/Pressure_regulatorhttp://en.wikipedia.org/wiki/Shuttle_valvehttp://en.wikipedia.org/wiki/Shuttle_valvehttp://en.wikipedia.org/wiki/Logical_disjunctionhttp://en.wikipedia.org/wiki/Logical_disjunctionhttp://en.wikipedia.org/wiki/Logical_disjunctionhttp://en.wikipedia.org/wiki/Check_valvehttp://en.wikipedia.org/wiki/Check_valvehttp://en.wikipedia.org/wiki/Fuse_%28hydraulic%29http://en.wikipedia.org/wiki/Fuse_%28hydraulic%29http://www.rotary-actuator.com/http://en.wikipedia.org/wiki/Fuse_%28hydraulic%29http://en.wikipedia.org/wiki/Check_valvehttp://en.wikipedia.org/wiki/Logical_disjunctionhttp://en.wikipedia.org/wiki/Shuttle_valvehttp://en.wikipedia.org/wiki/Pressure_regulator


16/108


Mechanical linear actuators operate by conversion of rotary motion into linear motion. Conversion is

commonly made via a few simple types of mechanism:

Screw:Screw jack,ball screw androller screw actuators all operate on the principle of thesimple machine known as the screw. By rotating the actuator's nut, the screw shaft moves in

a line. Wheel and axle:Hoist,winch,rack and pinion,chain drive,belt drive,rigid chain andrigid

belt actuators operate on the principle of the wheel and axle. By rotating a wheel/axle (e.g.

drum,gear,pulley orshaft)a linear member (e.g.cable,rack,chain orbelt)moves.[1]

Cam:Cam actuators function on a principle similar to that of thewedge,but providerelatively limited travel. As a wheel-like cam rotates, its eccentric shape provides thrust at the

base of a shaft.

Some mechanical linear actuators only pull (e.g. hoist, chain drive and belt drive) and others only

push (e.g. cam actuator).

CamsA linear actuatoris anactuatorthat, when driven by a non-linear motion, createslinearmotion (asopposed to rotary motion, e.g. of anelectric motor). Mechanical and hydraulic actuation are the most

common methods of achieving the linear motion.

A camis a rotating or sliding piece in a mechanicallinkageused especially in transforming rotarymotion into linear motion or vice-versa.[1][2]It is often a part of a rotatingwheel(e.g. an eccentric

wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes aleverat one or more points on

its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to asteam

hammer,for example, or aneccentricdisc or other shape that produces a smooth reciprocating (back

and forth) motion in thefollower,which is a lever making contact with the cam.

Gear train

A gear trainis a set or system ofgears arranged to transfer rotationaltorque from one part of amechanical system to another.

Gear trains may consist of:

Driving gears - attached to the input shaft Driven gears/Motor gears - attached to the output shaft Idler gears - interposed between the driving and driven gear in order to maintain the direction

of the output shaft the same as the input shaft or to increase the distance between the drive

and driven gears. A compound gear train refers to two or more gears used to transmit motion.
http://en.wikipedia.org/wiki/Machinehttp://en.wikipedia.org/wiki/Screw_%28simple_machine%29http://en.wikipedia.org/wiki/Screw_%28simple_machine%29http://en.wikipedia.org/wiki/Screw_jackhttp://en.wikipedia.org/wiki/Ball_screwhttp://en.wikipedia.org/wiki/Roller_screwhttp://en.wikipedia.org/wiki/Simple_machinehttp://en.wikipedia.org/wiki/Wheel_and_axlehttp://en.wikipedia.org/wiki/Wheel_and_axlehttp://en.wikipedia.org/wiki/Hoist_%28device%29http://en.wikipedia.org/wiki/Winchhttp://en.wikipedia.org/wiki/Rack_and_pinionhttp://en.wikipedia.org/wiki/Chain_drivehttp://en.wikipedia.org/wiki/Belt_drivehttp://en.wikipedia.org/wiki/Rigid_chain_actuatorhttp://en.wikipedia.org/wiki/Rigid_belt_actuatorhttp://en.wikipedia.org/wiki/Rigid_belt_actuatorhttp://en.wikipedia.org/wiki/Cylinder_%28geometry%29http://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Roller_chainhttp://en.wikipedia.org/wiki/Belt_%28mechanical%29http://en.wikipedia.org/wiki/Linear_actuator#cite_note-0http://en.wikipedia.org/wiki/Linear_actuator#cite_note-0http://en.wikipedia.org/wiki/Linear_actuator#cite_note-0http://en.wikipedia.org/wiki/Camhttp://en.wikipedia.org/wiki/Camhttp://en.wikipedia.org/wiki/Cam_actuatorhttp://en.wikipedia.org/wiki/Wedgehttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Linearhttp://en.wikipedia.org/wiki/Linearhttp://en.wikipedia.org/wiki/Linearhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Linkagehttp://en.wikipedia.org/wiki/Linkagehttp://en.wikipedia.org/wiki/Linkagehttp://en.wikipedia.org/wiki/Cam#cite_note-0http://en.wikipedia.org/wiki/Cam#cite_note-0http://en.wikipedia.org/wiki/Cam#cite_note-0http://en.wikipedia.org/wiki/Wheelhttp://en.wikipedia.org/wiki/Wheelhttp://en.wikipedia.org/wiki/Wheelhttp://en.wikipedia.org/wiki/Leverhttp://en.wikipedia.org/wiki/Leverhttp://en.wikipedia.org/wiki/Leverhttp://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Eccentric_%28mechanism%29http://en.wikipedia.org/wiki/Eccentric_%28mechanism%29http://en.wikipedia.org/wiki/Eccentric_%28mechanism%29http://en.wikipedia.org/wiki/Cam_followerhttp://en.wikipedia.org/wiki/Cam_followerhttp://en.wikipedia.org/wiki/Cam_followerhttp://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Mechanicshttp://en.wikipedia.org/wiki/Mechanicshttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Cam_followerhttp://en.wikipedia.org/wiki/Eccentric_%28mechanism%29http://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Steam_hammerhttp://en.wikipedia.org/wiki/Leverhttp://en.wikipedia.org/wiki/Wheelhttp://en.wikipedia.org/wiki/Cam#cite_note-0http://en.wikipedia.org/wiki/Cam#cite_note-0http://en.wikipedia.org/wiki/Cam#cite_note-0http://en.wikipedia.org/wiki/Linkagehttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Linearhttp://en.wikipedia.org/wiki/Actuatorhttp://en.wikipedia.org/wiki/Wedgehttp://en.wikipedia.org/wiki/Cam_actuatorhttp://en.wikipedia.org/wiki/Camhttp://en.wikipedia.org/wiki/Linear_actuator#cite_note-0http://en.wikipedia.org/wiki/Belt_%28mechanical%29http://en.wikipedia.org/wiki/Roller_chainhttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Cylinder_%28geometry%29http://en.wikipedia.org/wiki/Rigid_belt_actuatorhttp://en.wikipedia.org/wiki/Rigid_belt_actuatorhttp://en.wikipedia.org/wiki/Rigid_belt_actuatorhttp://en.wikipedia.org/wiki/Rigid_chain_actuatorhttp://en.wikipedia.org/wiki/Belt_drivehttp://en.wikipedia.org/wiki/Chain_drivehttp://en.wikipedia.org/wiki/Rack_and_pinionhttp://en.wikipedia.org/wiki/Winchhttp://en.wikipedia.org/wiki/Hoist_%28device%29http://en.wikipedia.org/wiki/Wheel_and_axlehttp://en.wikipedia.org/wiki/Simple_machinehttp://en.wikipedia.org/wiki/Roller_screwhttp://en.wikipedia.org/wiki/Ball_screwhttp://en.wikipedia.org/wiki/Screw_jackhttp://en.wikipedia.org/wiki/Screw_%28simple_machine%29http://en.wikipedia.org/wiki/Machine


17/108


Types of gear trains include:

Simple gear train Compound gear train Epicyclic gear train Reverted gear train

A gear train is two or more gear working together by meshing their teeth and turning each other in a

system to generate power and speed. It reduces speed and increases torque. To create large gear

ratio, gears are connected together to form gear trains. They often consist of multiple gears in the

train. The smaller gears are one-fifth of the size of the larger gear. Electric motors are used with the

gear systems to reduce the speed and increase the torque. Electric motor is connected to the driving

end of each train and is mounted on the test platform. The output end output end of the gear train is

connected to a large magnetic particle brake that is used to measure the output torque.

Types of Gear Trains

Simple Gear Train- The most common of the gear train is the gear pair connecting parallelshafts. The teeth of this type can be spur, helical or herringbone. The angular velocity is

simply the reverse of the tooth ratio. The main limitation of a simple gear train is that the

maximum speed change ratio is 10:1. For larger ratio, large size of gear trains are required.

The sprockets and chain in the bicycle is an example of simple gear train. When the paddle is

pushed, the front gear is turned and that meshes with the links in the chain. The chain moves

and meshes with the links in the rear gear that is attached to the rear wheel. This enables the

bicycle to move.

Compound Gear Train- For large velocities, compound arrangement is preferred. Twokeys are keyed to a single shaft. A double reduction train can be arranged to have its input

and output shafts in a line, by choosing equal center distance for gears and pinions.

Epicyclic Gear Train- It is the system of epicyclic gears in which at least one wheel axisitself revolves around another fixed axis.

Planetary Gear Train- It is made of few components, a small gear at the center called thesun, several medium sized gears called the planets and a large external gear called the ring

gear. The planet gear rolls and revolves about the sun gear and the ring gear rolls on the

planet gear. Planetary gear trains have several advantages. They have higher gear ratios.

They are popular for automatic transmissions in automobiles. They are also used in bicycles

for controlling power of pedaling automatically or manually. They are also used for power

train between internal combustion engine and an electric motor.

ApplicationsGear trains are used in representing the phases of moon on a watch or clock dial. It is also

used for driving a conventional two-disk lunar phase display off the day-of-the-week shaft of

the calendar.

Ratchet & pawl


18/108


A ratchetis a device that allows continuous linear or rotary motion in only one direction while

preventing motion in the opposite direction. Because most socket wrenchestoday use ratcheting

handles, the term "ratchet" alone is often used to refer to a ratcheting wrench, and the terms "ratchet"

and "socket" are closely associated in many users' minds.

A ratchet consists of a roundgear(see Figure 1) or linearrackwith teeth, and a pivoting,springloaded finger called apawl(or click[1])that engages the teeth. The teeth are uniform but

asymmetrical, with each tooth having a moderate slope on one edge and a much steeper slope on the

other edge.

When the teeth are moving in the unrestricted (i.e., forward) direction (see Figure 2), the pawl easilyslides up and over the gently sloped edges of the teeth, with a spring forcing it (often with an audible

'click') into the depression between the teeth as it passes the tip of each tooth. When the teeth movein the opposite (backward) direction, however, the pawl will catch against the steeply sloped edge of

the first tooth it encounters, thereby locking it against the tooth and preventing any further motion inthat direction.

Backlash

Because the ratchet can only stop backward motion at discrete points (i.e., at tooth boundaries), aratchet does allow a limited amount of backward motion. This backward motionwhich is limited

to a maximum distance equal to the spacing between the teethis calledbacklash.In cases where

backlash must be minimized, a smooth, toothless ratchet with a high friction surface such asrubber

is sometimes used. The pawl bears against the surface at an angle so that any backward motion will

cause the pawl to jam against the surface and thus prevent any further backward motion. Since the

backward travel distance is primarily a function of the compressibility of the high friction surface,

this mechanism can result in significantly reduced backlash.

Belt drives

A beltis a loop of flexible material used to link two or more rotatingshaftsmechanically. Belts may

be used as a source of motion, totransmit powerefficiently, or to track relative movement. Belts are

looped overpulleys.In a two pulley system, the belt can either drive the pulleys in the same

direction, or the belt may be crossed, so that the direction of the shafts is opposite. As a source of

motion, aconveyor beltis one application where the belt is adapted to continually carry a loadbetween two points.
http://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Gearhttp://en.wikipedia.org/wiki/Rack_and_pinionhttp://en.wikipedia.org/wiki/Rack_and_pinionhttp://en.wikipedia.org/wiki/Rack_and_pinionhttp://en.wikipedia.org/wiki/Ratchet_%28device%29#cite_note-0http://en.wikipedia.org/wiki/Ratchet_%28device%29#cite_note-0http://en.wikipedia.org/wiki/Ratchet_%28device%29#cite_note-0http://en.wikipedia.org/wiki/Backlash_%28engineering%29http://en.wikipedia.org/wiki/Backlash_%28engineering%29http://en.wikipedia.org/wiki/Backlash_%28engineering%29http://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Transmission_%28mechanics%29http://en.wikipedia.org/wiki/Transmission_%28mechanics%29http://en.wikipedia.org/wiki/Transmission_%28mechanics%29http://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Transmission_%28mechanics%29http://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Rubberhttp://en.wikipedia.org/wiki/Backlash_%28engineering%29http://en.wikipedia.org/wiki/Ratchet_%28device%29#cite_note-0http://en.wikipedia.org/wiki/Rack_and_pinionhttp://en.wikipedia.org/wiki/Gear


19/108


Belts are the cheapest utility for power transmission between shafts that may not be axially aligned.

Power transmission is achieved by specially designed belts and pulleys. The demands on a belt drive

transmission system are large and this has led to many variations on the theme. They run smoothly

and with little noise, and cushion motor and bearings against load changes, albeit with less strength

than gears or chains. However, improvements in belt engineering allow use of belts in systems that

only formerly allowed chains or gears.

Pros and cons

Belt drive, moreover, is simple, inexpensive, and does not require axially aligned shafts. It helps

protect the machinery from overload and jam, and damps and isolates noise and vibration. Loadfluctuations are shock-absorbed (cushioned). They need no lubrication and minimal maintenance.

They have high efficiency (90-98%, usually 95%), high tolerance for misalignment, and are

inexpensive if the shafts are far apart. Clutch action is activated by releasing belt tension. Different

speeds can be obtained by step or tapered pulleys.

The angular-velocity ratio may not be constant or equal to that of the pulley diameters, due to slipand stretch. However, this problem has been largely solved by the use of toothed belts. Temperatures

ranges from 31F (35C) to 185 F (85 C). Adjustment of center distance or addition of an idler

pulley is crucial to compensate for wear and stretch.

Flat belts

The drive belt: used to transfer power from the engine's flywheel. Here shown driving athreshing

machine.

Flat belts were used early inline shaftingto transmit power in factories.[1]

It is a simple system of

power transmission that was well suited for its day. It delivered high power for high speeds (500 hp

for 10,000 ft/min), in cases of wide belts and large pulleys. These drives are bulky, requiring high

tension leading to high loads, so vee belts have mainly replaced the flat-belts except when highspeed is needed over power. TheIndustrial Revolutionsoon demanded more from the system, and

flat belt pulleys needed to be carefully aligned to prevent the belt from slipping off. Because flat

belts tend to climb towards the higher side of the pulley, pulleys were made with a slightly convex or

"crowned" surface (rather than flat) to keep the belts centered. Flat belts also tend to slip on the

pulley face when heavy loads are applied and many proprietary dressings were available that could

be applied to the belts to increase friction, and so power transmission. Grip was better if the belt was

assembled with the hair (i.e. outer) side of the leather against the pulley although belts were also

often given a half-twist before joining the ends (forming aMbius strip), so that wear was evenly

distributed on both sides of the belt (DB). Belts were joined by lacing the ends together with leatherthonging,[2][3]or later by steel comb fasteners.[4]A good modern use for a flat belt is with smaller

pulleys and large central distances. They can connect inside and outside pulleys, and can come in

both endless and jointed construction.
http://en.wikipedia.org/wiki/Threshing_machinehttp://en.wikipedia.org/wiki/Threshing_machinehttp://en.wikipedia.org/wiki/Threshing_machinehttp://en.wikipedia.org/wiki/Threshing_machinehttp://en.wikipedia.org/wiki/Line_shafthttp://en.wikipedia.org/wiki/Line_shafthttp://en.wikipedia.org/wiki/Line_shafthttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Jenkins-0http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Jenkins-0http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Jenkins-0http://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/M%C3%B6bius_striphttp://en.wikipedia.org/wiki/M%C3%B6bius_striphttp://en.wikipedia.org/wiki/M%C3%B6bius_striphttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-1http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-1http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-1http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-3http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-3http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-3http://en.wikipedia.org/wiki/File:Transmissionsriemen.jpghttp://en.wikipedia.org/wiki/File:Transmissionsriemen.jpghttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-3http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-1http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-1http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-1http://en.wikipedia.org/wiki/M%C3%B6bius_striphttp://en.wikipedia.org/wiki/Industrial_Revolutionhttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Jenkins-0http://en.wikipedia.org/wiki/Line_shafthttp://en.wikipedia.org/wiki/Threshing_machinehttp://en.wikipedia.org/wiki/Threshing_machinehttp://en.wikipedia.org/wiki/Threshing_machine


20/108


Round belts

Round belts are a circular cross section belt designed to run in a pulley with a circular (or near

circular) groove. They are for use in lowtorquesituations and may be purchased in various lengthsor cut to length and joined, either by a staple, gluing or welding (in the case ofpolyurethane). Early

sewing machinesutilized a leather belt, joined either by a metal staple or glued, to a great effect.

Vee belts

Belts on aYanmar 2GM20marinediesel engine.

A multiple-V-belt drive on anair compressor.

Vee belts (also known as V-belt or wedge rope) solved the slippage and alignment problem. It is

now the basic belt for power transmission. They provide the best combination of traction, speed of

movement, load of the bearings, and long service life. The V-belt was developed in 1917 byJohn

Gatesof theGates Rubber Company.They are generally endless, and their general cross-sectionshape istrapezoidal.The "V" shape of the belt tracks in a mating groove in thepulley(or sheave),

with the result that the belt cannot slip off. The belt also tends to wedge into the groove as the load

increasesthe greater the load, the greater the wedging actionimprovingtorquetransmission

and making the V-belt an effective solution, needing less width and tension than flat belts. V-belts

trump flat belts with their small center distances and high reduction ratios. The preferred centerdistance is larger than the largest pulley diameter, but less than three times the sum of both pulleys.

Optimal speed range is 10007000 ft/min. V-belts need larger pulleys for their larger thickness thanflat belts. They can be supplied at various fixed lengths or as a segmented section, where the

segments are linked (spliced) to form a belt of the required length. For high-power requirements, two

or more vee belts can be joined side-by-side in an arrangement called a multi-V, running on

matching multi-groove sheaves. The strength of these belts is obtained by reinforcements with fiberslike steel,polyesteroraramid(e.g.TwaronorKevlar). This is known as a multiple-V-belt drive (or
http://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Polyurethanehttp://en.wikipedia.org/wiki/Polyurethanehttp://en.wikipedia.org/wiki/Polyurethanehttp://en.wikipedia.org/wiki/Sewing_machinehttp://en.wikipedia.org/wiki/Sewing_machinehttp://en.wikipedia.org/wiki/Yanmar_2GM20http://en.wikipedia.org/wiki/Yanmar_2GM20http://en.wikipedia.org/wiki/Yanmar_2GM20http://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Air_compressorhttp://en.wikipedia.org/wiki/Air_compressorhttp://en.wikipedia.org/wiki/Air_compressorhttp://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/wiki/Charles_Gates,_Jr.http://en.wikipedia.org/wiki/Charles_Gates,_Jr.http://en.wikipedia.org/wiki/Charles_Gates,_Jr.http://en.wikipedia.org/wiki/Trapezoidhttp://en.wikipedia.org/wiki/Trapezoidhttp://en.wikipedia.org/wiki/Trapezoidhttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Polyesterhttp://en.wikipedia.org/wiki/Polyesterhttp://en.wikipedia.org/wiki/Polyesterhttp://en.wikipedia.org/wiki/Aramidhttp://en.wikipedia.org/wiki/Aramidhttp://en.wikipedia.org/wiki/Aramidhttp://en.wikipedia.org/wiki/Twaronhttp://en.wikipedia.org/wiki/Twaronhttp://en.wikipedia.org/wiki/Twaronhttp://en.wikipedia.org/wiki/Kevlarhttp://en.wikipedia.org/wiki/Kevlarhttp://en.wikipedia.org/wiki/Kevlarhttp://en.wikipedia.org/wiki/File:Multiple-V-belt_drive_001.jpghttp://en.wikipedia.org/wiki/File:Multiple-V-belt_drive_001.jpghttp://en.wikipedia.org/wiki/File:Yanmar_2GM20.JPGhttp://en.wikipedia.org/wiki/File:Yanmar_2GM20.JPGhttp://en.wikipedia.org/wiki/Kevlarhttp://en.wikipedia.org/wiki/Twaronhttp://en.wikipedia.org/wiki/Aramidhttp://en.wikipedia.org/wiki/Polyesterhttp://en.wikipedia.org/wiki/Torquehttp://en.wikipedia.org/wiki/Pulleyhttp://en.wikipedia.org/wiki/Trapezoidhttp://en.wikipedia.org/wiki/Charles_Gates,_Jr.http://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=John_Gates_%28rubber%29&action=edit&redlink=1http://en.wikipedia.org/wiki/Air_compressorhttp://en.wikipedia.org/wiki/Diesel_enginehttp://en.wikipedia.org/wiki/Yanmar_2GM20http://en.wikipedia.org/wiki/Sewing_machinehttp://en.wikipedia.org/wiki/Polyurethanehttp://en.wikipedia.org/wiki/Torque


21/108


sometimes a "classical V-belt drive"). When an endless belt does not fit the need, jointed and link V-

belts may be employed. However they are weaker and only usable at speeds up to 4000 ft/min. A

link v-belt is a number of rubberized fabric links held together by metal fasteners. They are length

adjustable by disassembling and removing links when needed.

Multi-groove belts

A multi-groove or polygroove belt[5]is made up of usually 5 or 6 "V" shapes along side each other.

This gives a thinner belt for the same drive surface, thus is more flexible, although often wider. Theadded flexibility offers an improved efficiency, as less energy is wasted in the internal friction of

continually bending the belt. In practice this gain of efficiency is overshadowed by the reducedheating effect on the belt, as a cooler-running belt lasts longer in service.

A further advantage of the polygroove belt, and the reason they have become so popular, stems from

the ability to be run over pulleys on the ungrooved back of the belt. Although this is sometimes done

with vee belts and a single idler pulley for tensioning, a polygroove belt may be wrapped around a

pulley on its back tightly enough to change its direction, or even to provide a light driving force. [6]

Any vee belt's ability to drive pulleys depends on wrapping the belt around a sufficient angle of the

pulley to provide grip. Where a single-vee belt is limited to a simple convex shape, it can adequately

wrap at most three or possibly four pulleys, so can drive at most three accessories. Where more must

be driven, such as for modern cars with power steering and air conditioning, multiple belts are

required. As the polygroove belt can be bent into concave paths by external idlers, it can wrap anynumber of driven pulleys, limited only by the power capacity of the belt.[6]

This ability to bend the belt at the designer's whim allows it to take a complex or "serpentine" path.

This can assist the design of a compact engine layout, where the accessories are mounted moreclosely to the engine block and without the need to provide movable tensioning adjustments. The

entire belt may be tensioned by a single idler pulley.

Ribbed belt

A ribbed belt is a power transmission belt featuring lengthwise grooves. It operates from contact

between the ribs of the belt and the grooves in the pulley. Its single-piece structure it reported to

offer an even distribution of tension across the width of the pulley where the belt is in contact, a

power range up to 600 kW, a high speed ratio, serpentine drives (possibility to drive off the back of

the belt), long life, stability and homogeneity of the drive tension, and reduced vibration. The ribbed

belt may be fitted on various applications : compressors, fitness bikes, agricultural machinery, foodmixers, washing machines, lawn mowers, etc.[7]

Film belts

Though often grouped with flat belts, they are actually a different kind. They consist of a very thin

belt (0.5-15 millimeters or 100-4000 micrometres) strip of plastic and occasionally rubber. They aregenerally intended for low-power (10 hp or 7 kW), high-speed uses, allowing high efficiency (up to

98%) and long life. These are seen in business machines, printers, tape recorders, and other light-

duty operations.
http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-4http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-4http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-4http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Serpentine_belthttp://en.wikipedia.org/wiki/Serpentine_belthttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-6http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-6http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-6http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-6http://en.wikipedia.org/wiki/Serpentine_belthttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-Bosch.2C_Automotive_Handbook.2C_3rd_Ed.2C_Polygroove_belts-5http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-4


22/108


Timing belts

Timing belt

Belt-drive cog on abelt-driven bicycle

Timing belts,(also known as Toothed, Notch, Cog, or Synchronousbelts) are apositivetransfer

belt and can track relative movement. These belts have teeth that fit into a matching toothed pulley.

When correctly tensioned, they have no slippage, run at constant speed, and are often used totransfer direct motion for indexing or timing purposes (hence their name). They are often used in

lieu of chains or gears, so there is less noise and a lubrication bath is not necessary.Camshaftsof

automobiles, miniature timing systems, andstepper motorsoften utilize these belts. Timing belts

need the least tension of all belts, and are among the most efficient. They can bear up to 200 hp

(150 kW) at speeds of 16,000 ft/min.

Timing belts with a helical offset tooth design are available. The helical offset tooth design forms a

chevron pattern and causes the teeth to engage progressively. The chevron pattern design is self-

aligning. The chevron pattern design does not make the noise that some timing belts make at

idiosyncraticspeeds, and is more efficient at transferring power (up to 98%).

Disadvantages include a relatively high purchase cost, the need for specially fabricated toothed

pulleys, less protection from overloading and jamming, and the lack of clutch action.
http://en.wikipedia.org/wiki/Belt-driven_bicyclehttp://en.wikipedia.org/wiki/Belt-driven_bicyclehttp://en.wikipedia.org/wiki/Belt-driven_bicyclehttp://en.wikipedia.org/wiki/Timing_belthttp://en.wikipedia.org/wiki/Timing_belthttp://en.wikipedia.org/wiki/Camshafthttp://en.wikipedia.org/wiki/Camshafthttp://en.wikipedia.org/wiki/Camshafthttp://en.wikipedia.org/wiki/Stepper_motorhttp://en.wikipedia.org/wiki/Stepper_motorhttp://en.wikipedia.org/wiki/Stepper_motorhttp://en.wikipedia.org/wiki/Idiosyncratichttp://en.wikipedia.org/wiki/Idiosyncratichttp://en.wikipedia.org/wiki/File:F8hub.jpghttp://en.wikipedia.org/wiki/File:F8hub.jpghttp://en.wikipedia.org/wiki/File:Timing_belt.jpghttp://en.wikipedia.org/wiki/File:Timing_belt.jpghttp://en.wikipedia.org/wiki/Idiosyncratichttp://en.wikipedia.org/wiki/Stepper_motorhttp://en.wikipedia.org/wiki/Camshafthttp://en.wikipedia.org/wiki/Timing_belthttp://en.wikipedia.org/wiki/Belt-driven_bicycle


23/108


Specialty belts

Belts normally transmit power on the tension side of the loop. However, designs forcontinuously

variable transmissionsexist that use belts that are a series of solid metal blocks, linked together as ina chain, transmitting power on the compression side of the loop.

Rolling roads

Belts used for rolling roads for wind tunnels can be capable of 250 km/h.[8]

Flying rope

For transmission of mechanical power over distance without electrical energy, a flying rope can be

used[9].Awireormanila ropecan be used to transmit mechanical energy from asteam engineor

water wheelto a factory or pump which is located a considerable distance (10 to 100s of meters or

more) from the power source. A flying rope way could be supported on poles and pulleys similar tothe cable on achair liftoraerial tramway.Transmission efficiency is generally high.

Chain drives

Chain driveis a way of transmitting mechanical power from one place to another. It is often used to

convey power to the wheels of a vehicle, particularlybicyclesandmotorcycles.It is also used in a

wide variety of machines besides vehicles.

Most often, the power is conveyed by aroller chain,known as the drive chainor transmissionchain,[1]passing over asprocketgear, with the teeth of the gear meshing with the holes in the links

of the chain. The gear is turned, and this pulls the chain putting mechanical force into the system.

Sometimes the power is output by simply rotating the chain, which can be used to lift or drag

objects. In other situations, a second gear is placed and the power is recovered by attaching shafts or

hubs to this gear. Though drive chains are often simple oval loops, they can also go around corners

by placing more than two gears along the chain; gears that do not put power into the system or

transmit it out are generally known asidler-wheels.By varying the diameter of the input and output

gears with respect to each other, thegear ratiocan be altered, so that, for example, the pedals of a

bicycle can spin all the way around more than once for every rotation of the gear that drives the

wheels.

Chains versus belts

Drive chains are most often made of metal, while belts are often rubber, plastic, or other substances.

Although well-made chains may prove stronger than belts, their greater mass increases drive train

inertia.

Drive belts can often slip (unless they haveteeth)which means that the output side may not rotate at

a precise speed, and some work gets lost to thefrictionof the belt against its rollers. Teeth on

toothed drive belts generally wear faster than links on chains, but wear on rubber or plastic belts and
http://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-7http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-7http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-7http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-8http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-8http://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Manila_ropehttp://en.wikipedia.org/wiki/Manila_ropehttp://en.wikipedia.org/wiki/Manila_ropehttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Water_wheelhttp://en.wikipedia.org/wiki/Water_wheelhttp://en.wikipedia.org/wiki/Chair_lifthttp://en.wikipedia.org/wiki/Chair_lifthttp://en.wikipedia.org/wiki/Chair_lifthttp://en.wikipedia.org/wiki/Aerial_tramwayhttp://en.wikipedia.org/wiki/Aerial_tramwayhttp://en.wikipedia.org/wiki/Aerial_tramwayhttp://en.wikipedia.org/wiki/Bicyclehttp://en.wikipedia.org/wiki/Bicyclehttp://en.wikipedia.org/wiki/Bicyclehttp://en.wikipedia.org/wiki/Motorcyclehttp://en.wikipedia.org/wiki/Motorcyclehttp://en.wikipedia.org/wiki/Motorcyclehttp://en.wikipedia.org/wiki/Roller_chainhttp://en.wikipedia.org/wiki/Roller_chainhttp://en.wikipedia.org/wiki/Roller_chainhttp://en.wikipedia.org/wiki/Chain_drive#cite_note-MachinerysHandbook25epp2337-2361-0http://en.wikipedia.org/wiki/Chain_drive#cite_note-MachinerysHandbook25epp2337-2361-0http://en.wikipedia.org/wiki/Chain_drive#cite_note-MachinerysHandbook25epp2337-2361-0http://en.wikipedia.org/wiki/Sprockethttp://en.wikipedia.org/wiki/Sprockethttp://en.wikipedia.org/wiki/Sprockethttp://en.wikipedia.org/wiki/Idler-wheelhttp://en.wikipedia.org/wiki/Idler-wheelhttp://en.wikipedia.org/wiki/Idler-wheelhttp://en.wikipedia.org/wiki/Gear_ratiohttp://en.wikipedia.org/wiki/Gear_ratiohttp://en.wikipedia.org/wiki/Gear_ratiohttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Toothed_belthttp://en.wikipedia.org/wiki/Toothed_belthttp://en.wikipedia.org/wiki/Toothed_belthttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Toothed_belthttp://en.wikipedia.org/wiki/Inertiahttp://en.wikipedia.org/wiki/Gear_ratiohttp://en.wikipedia.org/wiki/Idler-wheelhttp://en.wikipedia.org/wiki/Sprockethttp://en.wikipedia.org/wiki/Chain_drive#cite_note-MachinerysHandbook25epp2337-2361-0http://en.wikipedia.org/wiki/Roller_chainhttp://en.wikipedia.org/wiki/Motorcyclehttp://en.wikipedia.org/wiki/Bicyclehttp://en.wikipedia.org/wiki/Aerial_tramwayhttp://en.wikipedia.org/wiki/Chair_lifthttp://en.wikipedia.org/wiki/Water_wheelhttp://en.wikipedia.org/wiki/Steam_enginehttp://en.wikipedia.org/wiki/Manila_ropehttp://en.wikipedia.org/wiki/Wire_ropehttp://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-8http://en.wikipedia.org/wiki/Belt_%28mechanical%29#cite_note-7http://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Continuously_variable_transmission


24/108


their teeth is often easier to observe; you can often tell a belt is wearing out and about to break more

easily than a chain.

Chains are often narrower than belts, and this can make it easier to shift them to larger or smaller

gears in order to vary the gear ratio. Multi-speed bicycles withderailleursmake use of this. Also, the

more positive meshing of a chain can make it easier to build gears that can increase or shrink indiameter, again altering the gear ratio.

Both can be used to move objects by attaching pockets, buckets, or frames to them; chains are often

used to move things vertically by holding them in frames, as in industrial toasters, while belts are

good at moving things horizontally in the form ofconveyor belts.It is not unusual for the systems tobe used in combination; for example the rollers that drive conveyor belts are themselves often driven

by drive chains.

Drive shaftsare another common method used to move mechanical power around that is sometimes

evaluated in comparison to chain drive; in particular shaft drive versus chain drive is a key design

decision for most motorcycles. Drive shafts te

Bearing

A bearingis a device to allow constrained relative motion between two or moreparts,typically

rotation or linear movement. Bearings may be classified broadly according to the motions they allow

and according to their principle of operation as well as by the directions of applied loads they canhandle.

Plain bearings use surfaces in rubbing contact, often with alubricant such as oil or graphite. A plain

bearing may or may not be adiscrete device. It may be nothing more than thebearing surface of a

hole with a shaft passing through it, or of a planar surface thatbears another (in these cases, not a

discrete device); or it may be a layer ofbearing metal either fused to the substrate (semi-discrete) or

in the form of a separable sleeve (discrete). With suitable lubrication, plain bearings often give

entirely acceptable accuracy, life, and friction at minimal cost. Therefore, they are very widely used.

However, there are many applications where a more suitable bearing can improve efficiency,

accuracy, service intervals, reliability, speed of operation, size, weight, and costs of purchasing and

operating machinery.
http://en.wikipedia.org/wiki/Derailleur_gearshttp://en.wikipedia.org/wiki/Derailleur_gearshttp://en.wikipedia.org/wiki/Derailleur_gearshttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Moving_partshttp://en.wikipedia.org/wiki/Moving_partshttp://en.wikipedia.org/wiki/Moving_partshttp://en.wikipedia.org/wiki/Plain_bearinghttp://en.wikipedia.org/wiki/Lubricanthttp://en.wiktionary.org/wiki/discrete#Adjectivehttp://en.wikipedia.org/wiki/Bearing_surfacehttp://en.wiktionary.org/wiki/bear#Verbhttp://en.wikipedia.org/wiki/Babbitt_%28metal%29http://en.wikipedia.org/wiki/Babbitt_%28metal%29http://en.wiktionary.org/wiki/bear#Verbhttp://en.wikipedia.org/wiki/Bearing_surfacehttp://en.wiktionary.org/wiki/discrete#Adjectivehttp://en.wikipedia.org/wiki/Lubricanthttp://en.wikipedia.org/wiki/Plain_bearinghttp://en.wikipedia.org/wiki/Moving_partshttp://en.wikipedia.org/wiki/Drive_shafthttp://en.wikipedia.org/wiki/Conveyor_belthttp://en.wikipedia.org/wiki/Derailleur_gears


25/108


Thus, there are many types of bearings, with varying shape, material, lubrication, principal of

operation, and so on. For example,rolling-element bearings use spheres or drums rolling between

the parts to reduce friction; reduced friction allows tighter tolerances and thus higher precision than a

plain bearing, and reduced wear extends the time over which the machine stays accurate. Plain

bearings are commonly made of varying types of metal or plastic depending on the load, how

corrosive or dirty the environment is, and so on. In addition, bearing friction and life may be altereddramatically by the type and application of lubricants. For example, a lubricant may improve bearing

friction and life, but for food processing a bearing may be lubricated by an inferior food-safe

lubricant to avoid food contamination; in other situations a bearing may be run without lubricantbecause continuous lubrication is not feasible, and lubricants attract dirt that damages the bearings.

Principles of

me2402 mechatronics lecture notes

Documents