high performance brake disc

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CHAPTER 1 1.INTRODUCTION 1.1 COMPANY PROFILE: Sakthi Auto Component Limited is one among the MULTI FACETED Sakthi Group situated at Mukasi Pallagoundenpalayam, Tripur District, Tamilnadu State, India, established in the year 1983. Presently the Sakthi Auto has a capacity to produce 24000 Tonnes / annum of S.G.IRON Castings, on a 100 Acre Land with all amenities for Workmen and Officers like Housing, Transport etc. Sakthi Auto is one of the major producers of S.G.Iron Castings, meeting the needs of most of the Automotive and other general Engineering Industries. 1

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Disc brakes are efficient than drum brakes in dissipating heat than drum type brakes. But the cast disks may have unbalanced distribution of mass throughout the disc. This project deals with the analysis of the uniform distribution of mass throughout the brake disc. Spots of excessive mass will be located and balancing is effected. Since the root cause of the unbalanced mass distribution may be due to faulty casting practises as well as defective pattern, these areas will also investigated to suggest for avoiding unbalanced mass distribution to a great extent.

TRANSCRIPT

Page 1: High Performance Brake Disc

CHAPTER 1

1.INTRODUCTION

1.1 COMPANY PROFILE:

Sakthi Auto Component Limited is one among the MULTI FACETED Sakthi

Group situated at Mukasi Pallagoundenpalayam, Tripur District, Tamilnadu

State, India, established in the year 1983. Presently the  Sakthi Auto has a

capacity to produce 24000 Tonnes / annum of S.G.IRON Castings, on a 100

Acre Land with all amenities for Workmen and Officers like Housing,

Transport etc. Sakthi Auto is one of the major producers of S.G.Iron

Castings, meeting the needs of most of the Automotive and other general

Engineering Industries.

FIGURE-1

Supplying most CRITICAL COMPONENTS like STEERING KUNCKLE,

BRAKE DRUMS and MANIFOLDS for all Suzuki Vehicles Manufactured

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in India by M/s. Maruti Udyog Limited at New Delhi & to many leading

passenger car manufacturers in fully machined condition.

R&D Lab is attached to our Sakthi Auto with modern computerised

equipments like Direct Reading Spectrometer, Carbon Sulphur determination,

Universal Testing Machine, Scanning Electron Microscope, Industrial X-RAY

Scanner etc.

FIGURE-2

Sakthi Auto is equipped with   DISAMATIC FOUNDRY with the state of

the art manufacturing technology which is regarded as the best anywhere in

the World. And equipped with many sophisticated special purpose and CNC

machines to produce precision oriented component for passenger car and

automobile industries.

The Moulding line which has been supplied by M/s. DISA Technologies of

DENMARK, is one of their latest and most efficient moulding line. It has

the capacity to produce 440 flawless moulds / hour. This would ensure closer

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tolerance and low rejection rates. It has Automatic Pouring Unit procured

from M/s. Asea Brown Boveri Ltd. And it maintains the consistency in the

metal temperature. Technical collaboration for melting technology has been

entered into with M/s. GEORGE FISHER FOUNDRY SYSTEMS,

SWITZERLAND, who are the world leaders for Manufacturing various

precision components for the Automobile Industries.

1.1.1 ABOUT SAKTHI AUTO COMPONENT INDUSTRY:

Meerut Machine Tool is a key Manufacturer and Supplier of high tech range

of machines, spares and tools. We have been dealing in Machine Tools,

Centrifugal Pumps, Blower, Industrial Blower Fan, Hydraulic Press, DPC

Machine, Grader, Rice Mill Parts, Chemical Plant Parts, etc. Our products are

developed from the optimum quality raw materials to ensure maximum strength

and life. The collection is ideally designed to provide high end performance to the

patrons with excellent durability and no maintenance features. We have been

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offering the range in different specifications and dimensions as per the needs of the

patrons.

Sakthi Auto Component Limited (SACL) is one of the multi faceted companies of

the Group. It is situated at Mukasi Pallagoundenpalayam, Tirupur District of

TamilNadu State, India.

Established in the year 1983 it hosts an advanced infrastructure built on a

sprawling 120 Acres Land with all Amenities including housing, transport, etc, for

its workmen and officers. The capacity of the plant was further enhanced to 60000

Tonnes/Annum with the High-pressure vertical Disamatic Green SandMoulding

Lines.

SACL is one of the few facilities in the country with in-house machining facility,

machining 95% of the components produced. SACL caters to the needs of Global

Automobile and truck manufacturers by supplying safety critical components like

Steering knuckles and Rotors to more than 3 Million Vehicles per annum. The top

customers for SACL are Maruti Suzuki, General Motors, Hyundai, Honda Siel

Cars, Ford, Fiat, Toyota, Volkswagen, Renault, Mahindra & Mahindra, Tafe,

Haldex and Volvo.

It is equipped with latest coating facilities like Geomet, Powder coating,

Phosphating and ED. SACL which has been certified with ISO/TS 16949:2009,

ISO14001:2004 and OHSAS 18001:2007 has Part Level Performance Validation

Lab setup to take care of impact and durability testing for all OEM’S.

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1.1.2 PRODUCTS OFFERED:

Machine Tools

Centrifugal Pumps

Blower

Industrial Blower Fan

Hydraulic Press

DPC Machine

Grader

Rice Mill Parts

Chemical Plant Parts

Sugar Mill Parts

Tyre Industries Parts

All Kinds Of Industrial Parts

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Commercial Auto Parts

Nature of Business :Supplier and Manufacturer

No. of Production Units :01

Monthly Production Capacity :As Per Order

No. of Engineers :02

Original Equipment Manufacturer :Yes

Year of Establishment :1980

Production Type :Semi- Automatic and Handmade

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CHAPTER 2

2.LITERATURE SURVEY:

In 2014, Borchate sourabh shivaji et al.[3] proposed “design analysis

and performance optimization of disc brake”. That has conducted an

experimental design analysis and performance optimization of disc brake. The

proposed methodology is optimization of weight of a disc of a disc brake is to be

studied. The scope of work is determining the thermal distribution of the existing

disk break application. Suggest design alternative for heat dissipation.

In 2013, M.S. Manikandan et al.[4] proposed “control of braking force under

loaded and empty conditions on two wheeler”. In this project main objective is

reducing the stopping distance of the two wheelers and providing a better braking

efficiency than the conventional braking system. The methodology is to find the

minimum stopping distance, measure the centre of gravity, calculate the dynamic

axle loads, modified braking system with antilock braking system, the result of the

project is to reduce the stopping distance, sliding of vehicle is reduced.

In 2011, Mesut duzgun et al. [1] proposed “investigation of thermo structural

behaviours of different ventilation application on brake discs”. The objective

of in this project is to use ventilation application on brake discs can significantly

improve the brake system performance by reducing the heating of the discs. The

methodology is thermal analysis, experimental study structural analysis, results and

discussion. Result of in this project is to increase the heat transfer from the brake

disc and to reduce the disc surface temperature on the total surface area of the

brake discs, the heat transfer coefficients are gradually increased by employing

ventilation applications.

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In 2013, P.Balashanmugam et al. [4] proposed “fabrication of high speed

indication and automatic pneumatic braking system”. An approach to high

speed indication is given and automatic braking is applied by cutting off the fuel

supply to the engine when the speed is exceeded. The methodology of in this

project is components can be described, engine construction, study of air brake,

describe the technical specifications. The conclusion is it’s flexible for all vehicles.

Speed control by engine arrangement is complicated; but in this method simple in

construction by lower expenses.

In 2014, Swapnil R.Abhang et al. [2] proposed “design and analysis of disc

brake”. The main objective is developed in order to meet safety requirement.

Instead of having air bag, good suspension systems, good handling and safe

cornering there is one most critical system in the vehicle which is brake system.

The following methodology can be used to find problem occurred in disc brake,

calculate the brake torque, brake distance, thermal analysis, modal analysis. The

result is action force and friction force on the disc brake new material, which use

disc brake works more efficiently, which can help to reduce the accident that may

happen in each day.

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CHAPTER 3

3. BRAKING SYSTEM – GENERAL DESCRIPTION

3.1 DEFINITION

The mechanism which is used to slow and stop the vehicle is known as

braking system. It is an important component of a vehicle.

3.1.1 PRINCIPLE OF BRAKING SYSTEM:

In this system, the kinetic energy is converted into heat energy due to

friction between two mating surfaces of brake lining and the brake drum. Then the

heat is dissipated into the atmosphere.

3.2 OVERVIEW:

Brakes are most important safety parts in the vehicles. Generally all

of the vehicles have their own safety devices to stop their car. Brakes

function to slow and stop the rotation of the wheel. To stop the wheel,

braking pads are forced mechanically against the rotor disc on both surfaces.

They are compulsory for all of the modern vehicles and the safe operation

of vehicles. In short, brakes transform the kinetic energy of the car into heat

energy, thus slowing its speed. Brakes have been retuned and improved ever

since their invention. The increases in travelling speeds as well as the growing

weights of cars have made these improvements essential. The faster a car goes and

the heavier it is, the harder it is to stop. An effective braking system is needed to

accomplish this task with challenging term where material need to be lighter than

before and performance of the brakes must

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be improved. Today's cars often use a combination of disc brakes and drum brakes.

For normal sedan car, normally disc brakes are located on the front two wheels and

drum brakes on the back two wheels. Clearly shows that, together with the steering

components and tires represent the most important accident avoidance systems

present on a motor vehicle which must reliably operate under various conditions.

However, the effectiveness of braking system depends on the design itself and also

the right selection of material. It is important to do some analysis on a disc brake

rotor which has been designed to predict the behavior of the systems than follow

with some improvements. In order to understand the behaviors of braking system,

there are three functions that must be complied for all the time (Smith, 2002);

1. The braking system must be decelerate a vehicle in a controlled and

repeatable fashion and when appropriate cause the vehicle to stop.

2. The braking should permit the vehicle to maintain a constant speed when

traveling downhill.

3. The braking system must hold the vehicle stationary when on the flat or

on a gradient.

Nowadays, there are lot of software has been developed in order to cater the

modeling and the finite element analysis on the vehicle component such as

MSC.ADAMS (Automatic Dynamic of Mechanical Systems), CATIA, MSC

PATRAN/NASTRAN, ANSYS, DYNA and ABAQUS. There is an advantage of

using that powerful computational analysis software where by using those would

make it easier, less cost, better accuracy and less computing time. Most of the

software is used in the wide range of industries such as automotive, oil and gas,

aerospace, marine, heavy duty engineering.

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3.3 HISTORY OF BRAKE SYSTEM DEVELOPMENT :

In the early days of the automobile, drum brakes were standard. Drum

brakes offered several advantages over other types of brakes. One of these was that

the drum could keep out water and dust, materials that could damage disc brakes

which were out in the open. Major advancement in brake technology came in 191 8

with the invention of four-wheel hydraulic brake systems by Malcolm Loughead.

The hydraulic brake system replaced the mechanical brake system that was in use

at this time. The mechanical system had numerous disadvantages. It made it

difficult to brake all the wheels evenly, often causing a loss of control. In addition,

it required drivers to exert tremendous amounts of force on the brake pedal to slow

the car. The hydraulic brake system multiplied the force that was applied to the

brake, lessening the amount of force needed to be applied to the brake pedal by the

driver. This system was first used in the 1918 Duesenberg. Its advantages quickly

caught on and by 1929, four wheel hydraulic braking systems were standard

equipment on higher priced cars. The main problem with drum brakes is that the

heat is not efficiently disbursed. The heat that is produced inside the drum does not

escape easily since the drum prevents wind from drawing it away. However, disc

brakes killed the issues when it allowed the heat to be carried away which

increased the efficiency of the brake. However, their use was limited up until the

1950's since their efficiency was not required and they required more pedal

pressure to operate. The reason for the higher pedal pressure is that disc brakes

have no self-servo effect or no self-energizing capacity that the drum brakes have.

The self-servo effect is caused by the forward motion of the car. This forward

motion helps pull the brake shoe into contact with the drum. This helped lower the

required pedal pressure.

Now that their efficiency was needed and the hydraulic brake system multiplied

the force applied to the brake pedal, disc brakes seemed to be the better

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alternative. Chrysler was the first to widely introduce the disc brake in its cars in

the early 1950'

The system did not have much success till automaker Studebaker to reintroduce

the system in 1964. This time it saw much more success and in a few years, disc

brakes were common on most new cars. One of the reasons that disc brakes

were a success with the Studebaker and not the Chrysler was due to the

development of the power braking system. Power brakes became common in the

195Ots, after Chrysler had developed and dropped its disc brake program.

The system assisted the movement of the piston in the master cylinder which

meant that the driver needed to apply less peddle pressure to get the same

braking effectiveness. Therefore, since ease of braking was no longer an issue,

the adoption of the more efficient disc brake became widespread.

3.4 TYPES OF BRAKES:

1.According to the applications:

Service or running foot brake

Parking or emergency or hand brake

2.According to the number of wheels:

Two wheel brakes

Four wheel brakes

3.According to the brake gear:

Mechanical brake

i. Hand brake

ii. Foot brake

Power brake

iii. Booster

iv. Non-booster

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4.According to construction:

Drum brake

Disc brake

5.According to location:

Transmission brakes

Wheel brakes

6.According to method of braking contact:

Internal expanding brakes

External expanding brakes

7. According to power unit:

Cylinder brake

Diaphragm brake

8. According to power transmission:

Direct acting brake

Geared brake

9. According to method of applying brake force:

Single acting brake

Double acting brake

10. According to power employed:

Vacuum brake

v. Atmospheric suspended

vi. Vacuum suspended

Air brakes

Hydraulic brakes

Hydrostatic brakes

Electric brakes.

3.5.1 AUTO BRAKE PADS CLASSIFIED FROM TYPE:

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1. Disc brake pads used for disc brakes.

2. Brake linings used for truck.

3. Brake shoes used for drum brakes.

3.6 CLASSIFIED FROM FORMULATION:

Asbestos, Non-asbestos, semi-metallic, Little-metallic, Ceramic.

Brake shoes corresponds to Brake drum, disc brake pads corresponds to

brake rotor, whatever disc brake pads, brake shoe or brake linings, Customary

all called brake pads.

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CHAPTER 4

4. BASIC BRAKE OPERATION:

4.1 ENERGY:

Can be defined as the ability to do work

4.1.1 WORK:

Transfer of energy from one physical system to another –especially the

transfer of energy to an object through the application of force.

Formula: Work = Force x Distance

4.1.2 AUTOMOTIVE BRAKES:

The force input by the driver is multiplied by the actuation system and

enables the energy of the vehicle’s motion to be transferred to the brake drums

or rotors where friction converts it into heat energy and stops the vehicle.

4.1.3 LATERAL RUNOUT

Side-to-side wobble of the rotor as it rotates on the spindle. If too great,

excessive pedal travel and front end vibration can result and lead to pedal

pulsation.

4.1.4 CAUSES:

Over-tightening or unevenly tightening wheel lug nuts or bolts Extreme

heat or rapid temperature variations in accurate machining.

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CHAPTER 5

5.DISC BRAKES:

Disc brakes are the most common brake systems used in vehicles today.

Typically located on the front wheels, they are comprised of brake pads, a brake

caliper, and a brake rotor. They function in the same way as brakes on a bike--

with brake pads on either side of the wheel that tighten when pressure is

applied. The resulting friction slows the wheel down and then brings it to a

complete stop. In the same way, disc brake pads straddle the rotor so that when

the driver applies the brakes, pressurized fluid is released causing the brake

caliper to squeeze the pads together and slow the vehicle down.

5.1 TYPES OF BRAKE DISC:

Essentially there are 4 types of brake disc:

Normal

Drilled

Grooved

Dimpled

5.1.1 NORMAL DISCS:

Exactly as you have on your car as standard, flat faced discs. They have

more surface area touching the pads when the brakes are applied so initially

have better braking power. The problem with normal discs is that as they heat

up you can get a build up of gas between the pad and the disc which causes

brake fade and pad glazing. The extra heat can also warp the discs if they are

poorly made or have been paired with in appropriate pads.

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5.1.2 DRILLED DISCS:

The face of these discs are drilled all the way through mainly to increase

surface area so they can rid themselves of heat quicker. The holes also go a little

way to stopping the gas build up that causes brake fade. The problem with

drilled discs is that the holes can have a tendency to start cracking and collect

dust and debris.

5.1.3 GROOVED DISCS:

The face of these discs have diagonal lines cut into them, there are two

reasons fothis. Firstly they allow the venting of brake pad gasses thus

eliminating brake fade. They also eject brake pad dust to stop glazing of the

pad. This keeps the pad face fresh allowing better braking. The problem is that

grooved discs have a tendancy to be louder when the brakes are applied due to

the scrubbing of the pads.

Discs with grooves should be installed a certain way round. As the disc rotates

in its

normal direction, the groove should be spinning outwards. This allows the brake

dust to be ejected away from the hub. Putting them on rotating the wrong way

can allow

the brake dust to accumulate in the centre of the hub.

5.1.4 DIMPLED:

The dimples in a disc clear debris from the pad but the main reason is to

reduce weight.

5.2 DIFFERENCE BETWEEN DIFFERENT TYPES OF DISC BRAKE

PADS:

The term "metallic" without any modifier gets used for a couple of

reasons- a) many manufacturers don't offer both varieties of metallic pads for a

given brake, so the type is implicit, and b) lots of folks don't know the

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difference or think the terms are interchangeable. They are similar, but

different:

Sintered metallic pads offer the best stopping power, but also cause the most

rotor wear and can make the most noise, especially when wet. They are also the

least affected by adverse conditions. Sintered metallic are typically used in

downhill/freeride applications, but can be used for less demanding riding types

as well. Depending on the setup, sintered pads can feel "grabby", that is, that

they lack modulation at the lever. That problem tends to arise on more powerful

brakes with larger rotors though, and both of those factors play towards that

perception.

Semi-metallics are a tradeoff between braking performance and pad wear/noise.

They still stop very well but can be a little less noisy and cause a little less rotor

wear. They may also offer better lever modulation than sintered metallic pads.

This pad type can often be found on higher end all-mountain, trail, and cross

country oriented brakes, though some manufacturers opt for sintered pads while

others may opt for organics.

Organic pads are the kindest to your rotors and typically quitest, but don't offer

the same bite as metallic pads. These pads also wear the quickest. This does not

mean that they're low end pads though, and depending on conditions, riding

style and personal preference they may be a great choice. Organic pads can

offer the best lever modulation of the three pad types, but may not stop riders

sufficiently in demanding circumstances.

5.3 DISK BRAKE DESIGN EQUATIONS:

The disc brake is a wheel brake which slows rotation of the wheel by the

friction caused by pushing brake pads against a brake disc with a set of calipers.

The brake disc (or rotor in American English) is usually made of cast iron, but

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may in some cases be made of composites such as reinforced carbon–carbon or

ceramic matrix composites. This is connected to the wheel and/or the axle. To

stop the wheel, friction material in the form of brake pads, mounted on a device

called a brake caliper, is forced mechanically, hydraulically, pneumatically or

electromagnetically against both sides of the disc. Friction causes the disc and

attached wheel to slow or stop. Brakes convert motion to heat, and if the brakes

get too hot, they become less effective, a phenomenon known as brake fade.

Let:

F = force on pad

r = mean radius of pad

A = pad area

Pad pressure: p = F/A

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CHAPTER 6

6. VERNIER CALIPER:

6.1 PARTS OF A VERNIER CALIPER:

1. Outside large jaws: used to measure external diameter or width of an

object

2. Inside small jaws: used to measure internal diameter of an object

3. Depth probe: used to measure depths of an object or a hole

4. Main scale: scale marked every mm

5. Main scale: scale marked in inches and fractions

6. Vernier scale gives interpolated measurements to 0.1 mm or better

7. Vernier scale gives interpolated measurements in fractions of an inch

8. Retainer: used to block movable part to allow the easy transferring of a

measurement

The vernier, dial, and digital calipers give a direct reading of the distance

measured with high accuracy and precision. They are functionally identical,

with different ways of reading the result. These calipers comprise a calibrated

scale with a fixed jaw, and another jaw, with a pointer, that slides along the

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scale. The distance between the jaws is then read in different ways for the three

types.

The simplest method is to read the position of the pointer directly on the scale.

When the pointer is between two markings, the user can mentally interpolate to

improve the precision of the reading. This would be a simple calibrated caliper;

but the addition of a vernier scale allows more accurate interpolation, and is the

universal practice; this is the verniercaliper.

Vernier, dial, and digital calipers can measure internal dimensions (using the

uppermost jaws in the picture at right), external dimensions using the pictured

lower jaws, and in many cases depth by the use of a probe that is attached to the

movable head and slides along the centre of the body. This probe is slender and

can get into deep grooves that may prove difficult for other measuring tools.

The vernier scales may include metric measurements on the lower part of the

scale and inch measurements on the upper, or vice versa, in countries that use

inches. Verniercalipers commonly used in industry provide a precision to

0.01 mm (10 micrometres), or one thousandth of an inch. They are available

insizes that can measure up to 1,829 mm (72 in).

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CHAPTER 7

7. DEFINITION OF UNBALANCE:

Unbalance can be defined as the condition which exists when the

principle mass axis of a rotating body, also known as the "Axis of Inertia", does

not coincide with the rotational axis.

7.1 SOURCE OF UNBALANCE:

Dissymmetry

Non-homogeneous material

Distortion at service speed

Eccentricity

Misalignment of bearing

Shifting of parts due to plastic deformation of rotor parts

Hydraulic or aerodynamic unbalance (cavitation or turbulence)

Thermal gradients

7.2 NOTATION OF UNBALANCE:

M: mass of a thin disc (unit: g)

m: unbalance mass (unit: g)

r: distance between the unbalance mass and axis of rotation (unit:

mm)

e: eccentricity, specific unbalance (unit: mm)

F: centrifugal force (unit: mN)

w: speed of rotation (unit: rad/sec)

There are three principle types of unbalance which are encountered:

Static Unbalance

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Couple Unbalance

Dynamic Unbalance

7.3 STATIC UNBALANCE:

Static Unbalance is present in a rotor when the mass axis does not

coincide with the rotational axis and is parallel to the rotational axis. This is also

known as "single plane" unbalance. The force created by this unbalance is equal

in magnitude at both the

bearing journals, and the angular position of the force vector is also the same at

both the bearing journals.

7.4 COUPLE UNBALANCE:

Couple Unbalance is present when the mass axis does not coincide with

the rotational axis, but does intersect the rotational axis at the center of gravity

of

the rotor. The force vectors created by this type of unbalance are equal in

magnitude at the bearing journals, but are 180 degrees opposite in direction.

7.5 DYNAMIC UNBALANCE:

Dynamic unbalance is defined as that condition where the mass axis does

not coincide with the rotational axis, is not parallel to its, and does not intersect

it. This condition is also known as "two plane" unbalance, Dynamic unbalance

is always a combination of Static and Couple unbalances.

7.6 UNBALANCE IN A SINGLE PLANE :

Such unbalance occurs in gear wheels, grinding wheels, single stage

compressors, blades of wind mills, the propeller of aircraft engines, shows a

rigid thin disc with the single plane unbalance. O is the centre of rotation of the

disc and G is the centre of gravity of the rotor. The eccentricity, e , is defined as

a distance between the centre of rotation and the centre of gravity, in practice

the tolerable eccentricity would be of the order of μm (however, it will very

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much depend upon the type of applications). The unbalance in the disc is

defined as,

U=me

where is the unbalance with a unit of kg-m or g-mm, m is mass of disc, e is the

eccentricity in the disc (length OG in Fig. 13.1). Even the order of eccentricity

is very less for large rotors, which generally runs at high speed, the effect of

unbalance force (meω2) could be devastating.

7.6.1 BASIC EQUATIONS IN BALANCING TECHNOLOGY:

"M" = Rotor Mass

"S" = Center of Mass

"e" = Displacement of Mass Center

"r" = Distance from center of rotor to C.G. of unbalance mass "m"

“ω” = Angular Velocity

"m" = Unbalance Mass

"U" = Rotor Unbalance

Unbalance in order to determine the unbalance "U" in the rotor,

the following equations are utilized:

U = M x e

or

U = m x r

Unbalance is always expressed as the product of mass times distance, such as

"gram-millimeters" or "ounce-inches" or "kilogram-meters".

7.7 CENTRIFUGAL FORCE:

To determine the amount of force produced by a given unbalance, the

formula:

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F = U x ω2 is used, where w is given as the angular velocity in radians per

second.

This can also be expressed as :

ω= 2πx RPM÷60

By combining these two formulas, we see that:

F = m x r x (2πx RPM)÷2(60).

7.8 BALANCE TOLERANCE:

The final point which must be addressed in this discussion is that of

balance quality, or how low of an unbalance is acceptable. The answer to this

question is readily available in the ANSI Standard for Balance Quality of

Rotating Rigid Bodies,ANSIS2.191975,which is identical to ISO 1940. The

purpose of these standards is to make recommendations concerning the balance

quality of rotating rigid bodies, particularly as it relates to the permissible

residual unbalance as a function of the maximum service speed of a particular

rotor. One of the functions of the ANSI standards is to assign balance quality

“grades” to different related groups of rotors, based on experience which was

gained with rotors of various types, sizes, and service speeds.

By definition, the balance quality grade “G” is equal to the product of

the specific unbalance, “e”

times the rotational speed “ω” or:

G = e x ω

The units for balance quality “G” are millimetres per second.

As we have seen earlier, “e” can also be defined as the unbalance “U” divided

by the rotor mass “M” or:

e = UM

where “U” is in gram⋅millimeters and “M” is in grams.

By substitution, we see that:

G = UxωM

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or

G = U (2 xπx RPM)÷M 60

CHAPTER 8

8.BALANCING MACHINE:

A balancing machine is a measuring tool used for balancing rotating

machine parts such as rotors for electric motors, fans, turbines, disc brakes,

disc drives, propellers and pumps. The machine usually consists of two rigid

pedestals, with suspension and bearings on top supporting a mounting

platform. The unit under test is bolted to the platform and is rotated either

with a belt-, air-, or end-drive. As the part is rotated, the vibration in the

suspension is detected with sensors and that information is used to determine

the amount of unbalance in the part. Along with phase information, the

machine can determine how much and where to add weights to balance the

part.

8.1 BALANCING MACHINE FOR BRAKE DISCS:

8.1.1 DESCRIPTION:

Soft-bearing vertical balancing machine for measuring and correcting

unbalance of disc-shaped rotors

Measuring, machining, and auditing in 1, 2, or 3 stations, depending on

cycle time requirements

For measuring, rotor is clamped using a high precision holder

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For unbalance correction, rotor is held by a swivelling chuck

Swarf is extracted via an exhaust hood mounted on the cutter head

Measuring computer performs sequencing, unbalance measurement, and

compensation calculation

8.1.2 APPLICATIONS:

Balancing of automotive brake discs and drums

Configuration as a manual single machine or fully integrated into a

production line

Loading options:

1. Manual

2. Interlinking with lift swivel transport

3. Gantry loader

4. Robot

Unbalance correction radially on the external disc diameter with side-

milling cutter

Feeding of workpieces in batch or mixed operation

8.1.3 ADVANTAGES:

Space saving and compact modular design

Fully automatic balancing with unbalance correction by milling

Measuring computer with touch-screen operation

Integration into production lines possible

Handling system designed for large tool range with reduced change over

time

Optional automatic calibration system with remount check (Hofmann

patent)

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8.2 OTHER BALANCING MACHINE TYPES:

Static balancing machines differ from hard- and soft-bearing machines in

that the part is not rotated to take a measurement. Rather than resting on its

bearings, the part rests vertically on its geometric center. Once at rest, any

movement by the part away from its geometric center is detected by two

perpendicular sensors beneath the table and returned as unbalance. Static

balancers are often used to balance parts with a diameter much larger than their

length, such as fans. The advantages of using a static balancer are speed and

price. However a static balancer can only correct in one plane, so its accuracy is

limited.

A blade balancing machine attempts to balance a part in assembly, so minimal

correction is required later on. Blade balancers are used on parts such as fans,

propellers, and turbines. On a blade balancer, each blade to be assembled is

weighed and its weight entered into a balancing software package. The software

then sorts the blades and attempts to find the blade arrangement with the least

amount of unbalance.

Portable balancing machines are used to balance parts that cannot be taken apart

and put on a balancing machine, usually parts that are currently in operation

such as turbines, pumps, and motors. Portable balancers come with

displacement sensors, such as accelerometers, and a photocell, which are then

mounted to the pedestals or enclosure of the running part. Based on the

vibrations detected, they calculate the part's unbalance. Many times these

devices contain a spectrum analyzer so the part condition can be monitored

without the use of a photocell and non-rotational vibration can be analyzed.

Gravity Balancing Machines

1. Non-rotating Balancers

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2. Static Balancing

`Centrifugal Balancing Machines

1. Static and Dynamic Balancing

2. Soft-Bearing Balancing Machines

3. Hard-Bearing Balancing Machines

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CHAPTER 9

9. DISC MODEL:

ITEM CODE : MAR00088

PART NO : 55311M55K00

PART NAME : DISC FRONT BRAKE MODEL “L”

CAR NAME : SX4 CROSSOVER CUV

9.1 METHODOLOGY :

Mapping

Reading

Graph

Measuring thickness with Vernier caliper Locating unbalance

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METHODOLOGY

31

MAPPING

DATA COLLECTION BY MEASUREMENT

[USING VERNIER CALIPER]

GRAPHICAL OBSERVATION OF RATE OF ADVERSE EFFECT

[UNBALANCING]

[LOCATING UNBALANCED POSITION]

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9.2 MAPPING:

Mapping means to mark the each vent in the brake disc. Fourty vent

avilable in this brake disc.

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9.2.1 3-D VIEW OF BRAKE DISC:

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9.2.2 2-D VIEW OF BRAKE DISC:

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9.3 MEASUREMENT:

9.3.1 UNBALANCED DISC:

NO.OF.VE

NT

PIECE

1

A

PIECE

1

B

PIECE

2

A

PIECE

2

B

1 7.26 7.7 7.16 6.6

2 7.3 6.6 7.26 7.4

3 7.34 6.5 7.16 6.78

4 7.2 6.5 7.26 6.58

5 7.18 6.6 7.2 6.48

6 7.16 6.54 7.18 6.68

7 7.06 6.5 7.2 7.58

8 7.08 6.4 7.06 7.58

9 7.86 6.5 7.9 6.68

10 7.86 7.8 7.88 6.58

11 7.8 7.7 7.8 6.48

12 7.78 6.48 7.8 6.5

13 7.79 6.5 7.78 6.68

14 7.78 6.5 7.7 6.68

15 7.7 6.48 7.98 6.68

16 7.7 6.4 7.5 6.7

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17 7.68 6.28 7.8 6.5

18 7.6 6.4 7.7 6.78

19 7.58 6.44 7.5 6.88

20 7.56 6.5 7.8 6.5

21 7.5 6.71 7.3 6.7

22 6.1 6.68 7.3 6.58

23 6.4 6.5 7.28 6.5

24 6.44 6.5 7.38 6.5

25 6.5 6.56 7.4 6.6

26 6.48 6.64 7.46 6.66

27 6.48 6.7 7.5 6.68

28 6.5 6.64 7.6 6.58

29 6.48 6.68 7.58 6.54

30 6.5 6.74 7.8 6.38

31 6.5 7.06 7.68 6.4

32 6.6 7.1 7.78 6.38

33 6.78 7.0 7.04 6.68

34 6.86 7.28 7.98 6.78

35 7.9 7.06 7.16 6.04

36 7.92 7.46 7.88 6.9

37 7.06 7.3 7.98 6.1

38 7.1 7.4 7.9 6.9

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39 7.12 7.38 7.44 6.7

40 7.1 7.06 7.48 6.8

9.3.2 BALANCED DISC:

NO..OF.VENT PIECE

1

A

PIECE1

B

PIECE2

A

PIECE2

B

1 7.26 7.6 7.16 6.6

2 7.3 6.6 7.26 7.4

3 7.34 6.5 7.16 6.78

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4 7.2 6.5 7.26 6.58

5 7.18 6.6 7.2 6.48

6 7.16 6.54 7.18 6.68

7 7.06 6.5 7.2 7.58

8 7.08 6.4 7.06 7.58

9 7.32 6.5 7.3 6.68

10 7.29 7.56 7.42 6.58

11 7.36 7.47 7.2 6.48

12 7.34 6.48 7.34 6.5

13 7.38 6.5 7.19 6.68

14 7.40 6.5 7.23 6.68

15 7.42 6.48 7.5 6.68

16 7.23 6.4 7.5 6.7

17 7.44 6.48 7.4 6.5

18 7.42 6.4 7.38 6.78

19 7.5 6.44 7.5 6.88

20 7.5 6.5 7.38 6.5

21 7.5 6.71 7.3 6.7

22 6.7 6.68 7.3 6.58

23 6.4 6.5 7.28 6.5

24 6.44 6.5 7.38 6.5

25 6.5 6.56 7.4 6.6

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26 6.48 6.64 7.46 6.66

27 6.48 6.7 7.5 6.68

28 6.5 6.64 7.50 6.58

29 6.48 6.68 7.5 6.54

30 6.5 6.74 7.18 6.38

31 6.5 7.06 7.34 6.49

32 6.6 7.1 7.43 6.38

33 6.78 7.0 7.04 6.68

34 6.86 7.28 7.20 6.78

35 7.3 7.06 7.16 6.49

36 7.2 7.46 7.28 6.9

37 7.06 7.3 7.48 6.1

38 7.1 7.4 7.45 6.9

39 7.12 7.38 7.44 6.7

40 7.1 7.06 7.48 6.8

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9.4 GRAPH:

9.4.1 UNBALANCING PIECE-1:

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9.4.2 BALANCING PIECE-1:

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CONCLUSION:

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