automobile power transmission

Power transmission

Power transmission

Power transmissionis the movement ofenergyfrom its place of generation to a location where it is applied to performing usefulwork.

What is power transmission ?

Fly wheel and clutch

Bell housing and input shaft

Drive shaft

Gear box

Differential

axle

Basic component of power transmission in a vehicle.

Power transmission assembely

The first link in the drive line or power transmission is the flywheel.

Fly wheel

Aflywheelis a rotating mechanical device that is used to storerotational energy. Flywheels have a significantmoment of inertiaand thus resist changes in rotational speed

what Is a fly wheel ?

First problem is the high mass of the fly wheel.

Second problem is the rotational inertia of the fly wheel.

Problems with the fly wheel.

for reducing the rotational inertia of the fly wheel we run the minimum diameter flywheel.

Choose a suitable material for increasing the efficiency of flywheel.

So the solutions.

Material selecting chart.
Chart shows that aluminum is best for making the fly wheel because it has low mass maximum strength.

Clutches is a mechanical device that are useful in devices that have two rotating shafts. In these devices, one of the shafts is typically driven by a motor or pulley, and the other shaft drives another device. In a drill, for instance, one shaft is driven by a motor and the other drives a drill chuck. The clutch connects the two shafts so that they can either be locked together and spin at the same speed, or be decoupled and spin at different speeds.

Clutch .

Clutch

In a car, you need a clutch because theenginespins all the time, but the car's wheels do not. In order for a car to stop without killing the engine, the wheels need to be disconnected from the engine somehow. The clutch allows us to smoothly engage a spinning engine to a non-spinning transmission by controlling the slippage between them.

why we need a clutch ?

Clutch working.

Bell housing.

Front and rear faces of the bell housing are not both true and parallel.

The pilot diameter at the rear of the bell housing into which the gearbox or transaxle spigots is not concentric with the crankshaft.

Misalignment in bell housing assembely.

a notable bending load is put into the input shaft to the detriment of the bearings involved and of the gear itself

It waste the power of the engine

This will result in a lost oil seal, oil on the clutch

Effect on the transmission

Adrive shaft is a mechanical component for transmittingtorqueand rotation, usually used to connect other components of adrive trainthat cannot be connected directly because of distance or the need to allow for relative movement between them.

Drive shaft.

Twisted driveshaft tube

Broken yoke shaft, slip yoke, tube yoke, flange yoke, end yoke

Broken journal cross

Universal Joint Operating Angles

Critical speed.

Causes of driveshaft vibrations.

Driveshaft critical speed measuring calculator.

3.Universal joint angle

improper universal joint causes many problems.

Vibrations

Reduced universal joint life

Problems with other drivetrain components that may include:

Transmission gear failures

Differential problems

Universal joint angle.

How we measure U-joint Angle

Place vehicle on level ground

No load on vehicle

Measure with an inclinometer

Transmission output shaft angle

Driveshaft tube angle

Pinion angle

Difference between output shaft and driveshaft tube is the front joint operating angle

Difference between pinion angle and driveshaft tube is rear joint operating angle

Measure u-joint angle

Drive shaft phasing.

When both of the u-joint in drive shaft are not in the same phase then this causes the vibration of drive shaft

Anaxleis a central shaft forarotating wheel

orgear. In the former case bearings or bushings are provided at the mountings points where the axle is supported

Axle .

Material.

mechanical design.

Heat treat.

Three things are very important
for any part of a machine.

Use 4340 steel-it has better through heat treating properties.

The only thing to avoid in the design of an axle is the stress raiser. Stress raisers are normally caused by rapid section changes and by sharp corners.

Natural places for these are at the end of splines.

Material and Design.

Axle break.

The spline i.D. and the i.D. of any snap grooves must be greater than the actual shaft O.D. and all radius must be as gentle as

Solution for design.

Half shaft-

the obvious necessity for the half shaft to be articulated they must have some provision to acommodate the axial plunge associated With the four bar independent suspension system If there is any notable resistance to this axial plunge, or change In half shaft length, the effect will be the same as a bind in the suspension and power application will be accompanied by a Jerky and unpredictable oversteer.

History of half shaft-

What is axial plunge

The classic solution was to use a splined two piece half shaft and let the splines accommodate the plunge Naturally the splines always bound up to some extent under torque loadings and this didn't work out very well.

first solution

Then Lotus came out with the fixed length half shaft which was also the upper link of the suspension system. This arrangement has

been perpetuated in the Corvette and the E Type Jaguar but the geometry is limited for race car use and the half shaft feeds some unnecessary loads into the final drive unit.

Second solution

Next came the rubber doughnut-which worked just fine so long as it was properly located and piloted but was limited in its ability to transmit torque. In its ultimate form (Brabham, Formula One) the drive shaft had two standard universals and a rubber doughnut

Third solution

Rzeppa type constant velocity joint half shaft which has been around forever

today

Maximum torsion bar length

Minimum weight and moment of inertia

Minimum package dimensions-which leaves more room for such things as exhaust systems and suspension links

Virtually frictionless axial plunge

Increased angular capacity and true constant velocity

Simplicity, reliability and cost

Adavantages of Rzeppa type half shaft

The differential is a device that splits the enginetorquetwo ways, allowing each output to spin at a different speed.

differential

To aim the engine power at the wheels

To act as the final gear reduction in the vehicle, slowing the rotational speed of the transmission one final time before it hits the wheels

To transmit the power to the wheels while allowing them to rotate at different speeds (This is the one that earned the differential its name.)

The differential has three jobs:

Why we need a differential

Open differential.

Spool differential

Detroit differential

Locked differential

Limited slip differential

Types of differential which are commonly used.

Working of open differential

It sends equal amount of torque to the both of the wheels which is not good in some situations. It is good for an on road vehicle.

Limitations of open differential.

Spool differential

The spool simply ties the two wheels together eliminating all differential action. The housing itself is internally splined to receive the drive axles. The driving torque, taken from the ring gear drives the axles directly. Both wheels turn at the same speed regardless of traction levels, or direction of travel. This means that when equipped with a spool, the car naturally wants to go straight, regardless of steering input

Drawbacks of spool differential

handling suffers greatly when using a spool, because the tied-together wheels cause massive steer.

Another very significant downside to the spool is that when you are leaving the track with hot tires, the torque generated in turns can easily be enough to break axles. Remember that on the track, the inside wheel is unweighted, reducing its traction; so that the torque required to force the inside wheel to slip in the turns is reduced. When leaving the track, the weight is equal on both hot tires, the maximum grip possible on both tires will be achieved with the inside tire fighting the outside tire.

Detroit differential.

The operating principal of the Detroit Locker is much like that of a bicycle rear wheel sprocket. It was originally built for drag racing to allow the turnoff at the end of a run with less stress induced in the axles. When turning off, the faster wheel will unlock allowing it to coast through the corner. This is a great setup for drag racing and off-road use. However, in a road racing application only the inside wheel will drive creating massive mid turn understeer. Only when the inside tire slips and catches up with the outside tire will the outside tire begin to drive.At this point, the Detroit Locker becomes a spool,

The basic rule of road racing with a Detroit Locker is the same as a spool. DO
NOT USE IT unless it is required by the rules

A locking differential may provide increasedtractioncompared to a standard, or "open" differential by restricting each of the two wheels on an axle to the same rotational speedwithout regard to available traction or differences in resistance seen at each wheel.

Locked differential

Some off road situation in which the locked differential is suitable. in these situations the torques in the both tires are limited by the function of the locked differential

Because they do not operate as smoothly as standard differentials, automatic locking differentials are often responsible for increased tire wear

Some locking differentials are known for making a clicking or banging noise when locking and unlocking as the vehicle negotiates turns.

some locking differentials can affect the ability of a vehicle to steer in some situations,

Disadavantages

They are also capable of subjecting the axle shafts to much higher torque loads than would be possible with an open differential because they allow 100% of the available torque to carried by a single axle shaft as opposed to being divided up between the two. Under extreme conditions, this can cause an axle shaft failure.

Disadavantages

Four wheel drive vehicles that drive off-road often use locking differentials to prevent from getting stuck when driving on loose, muddy, or rocky terrain. Locking differentials are considered essential equipment for serious off-road driving.

Some utility vehicles such as tow trucks, forklifts, tractors, and heavy equipment use locking differentials to maintain traction, especially when driving on soft, muddy, or uneven surfaces. Lockers are common in agricultural equipment and military trucks.

application

A limited slip differential is a device found in the driveaxleof an automobile or truck that the axles and ring gear are mounted to. Used to engage both sides of the axle in the event of needed traction, the limited slip differential causes both drive tires to receive power, resulting in added traction. Unlike a locked, welded or spooled differential that has both sides of the axle meshed together constantly, the limited slip differential is made so that thedrive axle will disengage one side while turning a corner. This prevents the wheels from binding and the tires from chirping as the outside tire fights to turn faster than the inside tire while the vehicle negotiates a sharp turn.

Limited slip differentials

Comparison b/w lock and lsd

Lock differential

Limited slip differential

it is better for only off road vehicle not good in general on road vehicle.

It causes the wear of tires when turn on a smooth road .

It locks the tires 100%.

it is better for both off road and on road

on the smooth road or pavements it behaves just like a open differential and on the off road like a lock differential.

It does not lock 100%

Manual transmission

Automatic transmission

Cvt(continuously variable transmission)

Types of transmission.

manual transmission gear box.

Hewland gear box

Baulk ring gear box

Types of manual transmission gear box but these are generally used for formula cars.

there are two big differences between an automatic transmission and amanual transmission:

There is no clutch pedal in an automatic transmission car.

There is no gear shift in an automatic transmission car. Once you put the transmission intodrive, everything else is automatic.

Automatic transmission.

Automatic transmission gear box.

inputoutputstationarycalculationGear ratio

first gearsunPlanet carrierRing gear1+r/s3.4:1

Third gearPlanet carrierringsun1/(1+s/r).71:1

Reverse gearsunringPlanet carrier-r/s-2.4:1

Automatic transmission working by simple one planet gear

Ring=72teethSun=30teeth

Comparison b/w manual and automatic transmission.

manual

automatic

Manual gearshifts are more fuel efficient as compared to their automaticcounterpart

It provides better control over vehicle.

It is very simple and little costly

Torque convertor used to engage and disengage automatic gears may lose power and reduce acceleration as well as fuel economy.

It provides less control

An automatic transmission is made up of several components and a breakdown of even a single component can stall the car completely.

Comparison b/w manual and automatic

manual

automatic

A manual is better because you have lower gearing in 1st which means more for climbing.

An automatic provides some higher first gear ratio than a manual

Unlike traditional automatic transmissions, continuously variable transmissions don't have a gearbox with a set number of gears, which means they don't have interlocking toothed wheels. The most common type of CVT operates on an ingeniouspulley systemthat allows an infinite variability between highest and lowest gears with no discrete steps or shifts.

Cvt transmission.

Pulley-belt cvt

Torodial cvt

Hydrostatic cvt

Types of cvt

feature benefit

Constant, stepless acceleration from a complete stop to cruising speed

Eliminates "shift shock" -- makes for a smoother ride

Works to keep the car in its optimum power range regardless of how fast the car is traveling

Improvedfuel efficiency

Responds better to changing conditions, such as changes in throttle and speed

Eliminates gear hunting as a car decelerates, especially going up a hill

Responds better to changing conditions, such as changes in throttle and speed

Better acceleration

Adavantages of cvt

Cvt is better than manual and automatic transmission but requires some experience for handling vehicle

Conclusion-

By-Chetan badsar

2015/11/3

Click to edit the title text formatClick to edit Master title style

Click to edit Master text styles

Second level

Third level

Fourth level

Fifth level

Click to edit Master title style

Click to edit Master subtitle style

2015/11/3


Click to edit Master text stylesSecond level

Third level

Fourth level

Fifth level

2015/11/3



2015/11/3



Third level

Fourth level

Fifth level


Third level

Fourth level

Fifth level

2015/11/3




Third level

Fourth level

Fifth level



Third level

Fourth level

Fifth level

2015/11/3


2015/11/3

2015/11/3



Third level

Fourth level

Fifth level


2015/11/3



2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3

Click to edit the outline text format

Second Outline Level

Third Outline Level

Fourth Outline Level

Fifth Outline Level

Sixth Outline Level

Seventh Outline Level

Eighth Outline Level

Ninth Outline LevelClick to edit Master text styles

Second level

Third level

Fourth level

Fifth level

2015/11/3




2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3



2015/11/3



Second level

Third level

Fourth level

Fifth level


Second level

Third level

Fourth level

Fifth level

2015/11/3




Second level

Third level

Fourth level

Fifth level



Second level

Third level

Fourth level

Fifth level

2015/11/3


2015/11/3

2015/11/3



Second level

Third level

Fourth level

Fifth level


2015/11/3



2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3




Third Outline Level


Fifth Outline Level

Sixth Outline Level






Third Outline Level


Fifth Outline Level

Sixth Outline Level






Third Outline Level


Fifth Outline Level

Sixth Outline Level




Second level

Third level

Fourth level

Fifth level



Third Outline Level


Fifth Outline Level

Sixth Outline Level




Second level

Third level

Fourth level

Fifth level

2015/11/3



2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3



2015/11/3



Second level

Third level

Fourth level

Fifth level


Second level

Third level

Fourth level

Fifth level

2015/11/3




Second level

Third level

Fourth level

Fifth level



Second level

Third level

Fourth level

Fifth level

2015/11/3


2015/11/3

2015/11/3



Second level

Third level

Fourth level

Fifth level


2015/11/3



2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3



Second level

Third level

Fourth level

Fifth level

2015/11/3

automobile power transmission

Engineering