Tire Terminology Camber angle angle between the wheel plane and the vertical taken to be positive when the wheel leans outwards from the vehicle kingpin inclination angle between the swivel pin axis and the vertical kingpin offset distance between the centre of the tire contact patch and intersection of the swivel pin axis and the ground plane Castor angle inclination of the king pin axis plane through the wheel centre provides a self-aligning torque for non-driven wheels. Toe-in and Toe-out difference between the front and rear distances separating the centre plane of a pair of wheels, toe-in is when the wheel centre planes converge towards the front of the vehicle

SUSPENSION It is a system which is responsible for forcing car to be on the ground and making the ride of the occupants comfortable. Objectives :To provide good ride and handling performance To ensure that steering control is maintained during all scenarios.To ensure that the vehicle responds properly to control forces produced by the tires during longitudinal braking accelerating forces, lateral cornering forces and braking and accelerating torques this requires the suspension geometry to be designed to resist squat, dive and roll of the vehicle body

The mobility of suspension mechanisms :It guides motion of each wheel along vertical path relative to the vehicle body without significant change in camber.

Suspension Types -Dependent Motion of a wheel on one side of the vehicle is dependent on the motion of its partner on the other side Cannot give good ride Cannot control high braking and accelerating torques

Semi-dependent Suspension :the rigid connection between pairs of wheels is replaced by a compliant link. a beam which can bend and flex controls the position of the wheels lacks scope for design flexibility

Trailing twist axle suspensionSuspension Types - Independent motion of wheel pairs is independent, so that a disturbance at one wheel is not directly transmitted to its partner Better ride and handling Macpherson Strut Multi linkDouble wishbone

MacPherson suspensionIt is most widely used front suspension system in cars .The system basically comprises of a strut-type spring and a shock absorber combo, the upper part of the coil is supported on the body of the car, and the lower part on a cup integral with the body of the shock absorber, which also constitutes the pivotal axis of the steering. When you steer, it physically twists the strut and shock absorber housing to turn the wheel, the whole assembly turns on a bearing plate or ball race at the top, and on the bottom ball joint of the lower arm. This allows a twisting motion to take place.

Chassis :FUNCTIONS: To safely carry the maximum load. Holding all components together while driving. Take care shock loading. It must absorb torque which get applied.

Types of Chassis frame: Conventional Frame Integral Frame Semi Integral frameConventional Frame: It is also known as non load carrying frame. Here loads on thevehicles are transferred to the suspensions by frame. This type of frame is not suited to resist torsionSemi Integral Frame:In this type of frame load is transferred to the body structurealso. This Frame is heavy.In semi integral frame half frame is fixed in the front end onwhich engine gear box and front suspension is mounted.

Integral Frame: In this type of construction there is no frame and all assemblyunits are attached to the body.The chassis , floor and body are assembled by from a largenumber of mild steel pressings.Some of important Chassis are: Ladder Frame Tabular Space Frame Monocoque Frame ULSAB Monocoque Backbone Frame Aluminum Space Frame Carbon FibreLadder frame: The ladder frame is the simplest and oldest of all designs. This design offers good beam resistance because of its continuous rails from front torear, poor resistance to torsion.

Tubular space frame: It is 3-dimensional design.Tubular space frame chassis employs dozens of circular section tube, positions in different directions to provide mechanicalstrength against force from anywhere.These tubes are welded & forms a very complex structure.

Very strong in any direction Very complex , costly and time consuming to be built.Monocoque: Monocoque is a one-piece structure which defines overall shapeof the car. while ladder , tabular & backbone provide only stress members. Monocoque chassis are made by welding of several pieces.Backbone chassis: A strong tubular backbone connects the front & rear axle & provide nearly all mechanical strength. The whole drivetrain , engine & suspensions are connected to both ends ofthe backbone. The body is built on backbone are usually made of glass-fibre.

Eassy to be made by hand Spce efficient Good crash production

TRANSMISSION : The mechanism that transmits the power developed by the engine ofautomobile to the engine to the driving wheels is called the TRANSMISSION SYSTEM .It is consists of Clutch The gear box Propeller shaft Universal jointsRear axle Wheel Tyres

Requirements Of Transmission System :- Provide means of connection and disconnection of engine with rest ofpower train without shock and smoothly. Provide a varied leverage between the engine and the drive wheels Provide means to transfer power in opposite direction. Enable power transmission at varied angles and varied lengths. Enable speed reduction between engine and the drive wheels in the ratioof 5:1. Enable diversion of power flow at right angles. Provide means to drive the driving wheels at different speeds whenrequired. Bear the effect of torque reaction , driving thrust and braking effort effectively.CLUTCHA clutch is a mechanism which enables the rotary motion of one shaft to be transmitted at will to second shaft ,whose axis is coincident with that of first. Clutch is located between engine and gear box. When the clutch is engaged, the power flows from the engine to the rear wheels through the transmission system and the vehicle moves . when the clutch is disengaged ,the power is not transmitted to the rear wheels and the vehicle stops, while the engine is still running. Clutch is disengaged when a)Starting the engine,b) Shifting the gears,c) Idling the engine clutch is engaged only when the vehicle is to move and is kept engaged when the vehicle ismoving. GEAR BOX:gear box provides varying speed and torque. it provides high torque at the time of starting, vehicle acceleration, climbing up a hill. To provide speed more than forward speeds by providing more than one gear ratios.Gear box provides a reverse gear for driving the vehicle in reverse direction. TYPES OF GEAR BOXES (a) Selective type gear boxes : (i) Sliding mesh gear box (ii) Constant mesh gear box (iii) Synchromesh gear box (b) Progressive type gear box (c) Epicyclic type gear box.

GEAR TRAINS A combination of two or more gears, which mesh in such a way that power is transmitted from driving shaft to driven shaft, is known as gear train. TYPES OF GEAR TRAINS There are three types of gear trains : (a) Simple gear train, (b) Compound gear train, and (c) Epicyclic gear train.