• What is an Automobile ?

• How does it work ?

• What makes it work ?

An object which moves or propels by itself on its own is known as Auto-

Mobile.

Mechanical energy is converted into Motion

• Any Automobile consists of Power-train and Non power-train components.

• Parts involved in the process of generating power to converting it to Motion are called Power-Train components.

• Parts like Body, Frame, Interiors and Steering are Non Power-Train components.

• Engine• Clutch• Transmission• Propeller Shafts• Differential

Engine

• Four major functions take place in the engine.

• Suction, Compression, Combustion and Exhaust.

• Block without the cylinder head and its components and crank case and its components is called short block assy.

• Head, Crank and Cam shafts FIP or Carb. Air cleaner and the radiator and Engine oil filter are the components mounted on the engine.

• Engines can be mounted on the rear end and the vehicles are called rear engine Vehicles.

In order to create mechanical energy, car engines needs to combust (explode) gasoline in a closed chamber to push off a mechanical part

(piston) down and up. The up and down motion of the piston creates a circular motion in the crankshaft via the connecting rods. This is more

clearly seen in the animated pictures below.

Short Block

V Block EngineSpark Plug Engine

4 Strokes

Clutch or Torque converter

• It connects and disconnects the power generated by the Engine form the rest of the transmission.

• It can be automatic or manually operated.

• This consists of a Disc and Pressure Plate or Plates and also available in a fluid model which is called “Torque Converter”.

• Any sort of defect in driving would first reflect on this part.

• Efficiency in driving the vehicle depends on the efficiency of the Clutch and vise versa.

An apparatus that disconnects the engine from the transmission in order for the car to change gears and then enables the gears to resume contact and turn together at a new speed.

Gear Box or Transmission

• This device transmits the power to the propeller shaft changing the RPM.

• It can be automatic or Manually operated.

• In a car it is operated with the help of Gear lever which helps the driver the gears according to his requirement.

• In a manually operated Gear box it is mandatory to engage the clutch and then change the gear.

• Constant Mesh and Syncro Mesh are the types of the gear boxes.

Multiplies engine torque via gear reduction and/or torque conversion. A typical manual transmission has four or five speeds, with the final or highest gear being either a direct 1:1 drive ratio or an "overdrive" ratio (less than 1:1).

Gear Box Mechanism

Propeller Shaft or Drive

shaft

• It carries the power from the Transmission or the Gearbox to the Differential.

• It is a long tube like structure made up of hard steel.

• It is provided with universal Joints at one end and the other has splines to fit it inside the yoke.

• If there are multiple shafts in the vehicle, it can be mounted in the cross member of the frame and also can be inserted into the center bearing and mounted in the member.

Drive Shaft Mechanism

Transmits engine torque to the differential, or from the differential to the drive wheels.

Differential or Rear Final Drive

• It is a very important device which converts mechanical energy to Motion.

• It provides less motion to the inner wheel and greater motion to the outer wheel while the vehicle is being turned.

• Drive pinion and Driven gear and Planetary gear assy. are the important parts installed inside the housing.

• It holds the wheel hubs and break drums and the cylinders and also carry half axel shafts which help in moving the vehicle.

A special gearbox designed so that the torque fed into it is split and delivered to two outputs that can turn at different speeds.

Differential Mechanism

The End