Differential and Rear Axle Drives, by Jeevan B M

AUTOMOTIVE ELECTRONICS 1

Presented by,JEEVAN B MUSN- 4JC15MEE11

DIFFRENTIAL AND REAR AXLE DRIVES


Introduction of differential drive Construction of differential drive Principle and working of differential drive Functions of differential. Rear axial drive Types of rear axil drive Advantages and disadvantages of rear axial

drive References

CONTENTS


A differential is a device capable of transmitting torque and rotation through three shafts, almost always used in one of two ways.

In one way, it receives one input and provides two outputs; this is found in most automobiles

A differential is used to allow the wheels to spin at different speeds

The function of the differential unit is to allow different speeds to the two wheels

INTRODUCTION


• When a car is moving along a bend in the road. Its inner wheel will be rotating at a speed lower than that of its outer wheel


Construction of differential


Principle and operation of differential

inner wheel axle has been stopped by hand. But the differential unit is still rotating. Thus the outer wheel can now rotate at a faster speed. A similar arrangement is made in the differential unit


working of the differential


At the time of straight road• During the vehicle runs straight, the wheels of the rear

axle will be screened by the drive pinion through the ring gear differential case, wheel-wheel differential gear pinion shaft, side gear teeth is not spinning, remain to be drawn into the ring gear rotation.

• Thus the spin on the wheel left and right alikeAt the time of turning• At the time of vehicle turning left prisoners left wheel is

bigger than the right wheel.• If the differential case with the ring gear rotates the

pinion will rotate on its axis and also the movement around the left side gear, so round the right hand side gear increases, the side where the number of revolutions of the gear which is 2 times round the ring gear.


Functions of the differential system are

• Further reduces the rotations coming from the gear box before the same are passed on to the rear axles.

• Changes the direction of axis of rotation of the power by 90o i.e. from being longitudinal to transverse direction.

• To distribute power equally to both the rear driving axles when the tractor is moving in straight ahead direction.

• To distribute the power as per requirement to the driving axles during turning.


Rear axle drives

Rear axle drives are the drives which employed for the rear axle the spring take the weight of the body.

In most of the front engine rear wheel drive cars, rear axles are used for transmitting power from differential to driving wheels.

rear axle avoid bending load.


• various forces and torques experienced by the rear axle

Torque reactionDriving trust(trust to be produced in the road due to humps)Weight of the body(cause bending movement in the axle shaft)The side way forces(moving along the curves)


Types of rear axle drives

Many drives are used out of which two important ones are:1. Hotchkiss drive.2. Torque tube drive


Hotchkiss drive


In this case the springs besides the taking weight of the body, also take the torque reaction, driving thrust and the side thrust.

Due to torque reaction, the spring deflects as shown in figure thus torque reaction is taken up by the springs

To take up the braking torque the springs would deflect in the opposite direction.


Torque tube drive:

In this type spring takes body weight and side thrust onlyThe torque reaction and driving thrust are taken by another member called torque tube


Advantages and disadvantages of rear axle drives:

Advantages: Better handling in dry conditions. More predictable steering in low traction condition(ie ice or

gravel). Less costly and easier maintenance. Even weight distributions.

Disadvantages: More difficult to master. Decreased interior space. Increased weight• Higher purchase price


REFERENCES

Book of automotive mechanics by S SRINIVASAN www.mlees-robotronics.in/home/robotics/differential-

drive-mechanismDIfferential drive mechanism Wikipedia- Differential(mechanism) www.learnengineering.org/2014/05/working-of-

differential.html Book of automobile engineering by Dr. KIRPAL SINGH


THANK YOU ALL

Differential and Rear Axle Drives, by Jeevan B M

Automotive

Transcript of Differential and Rear Axle Drives, by Jeevan B M