Power Transmission to the Wheels | Types of Power Transmission to the Wheels

Power transmission to the wheels

There are different arrangements by which engine power is transmitted to the wheels. The usual arrangements and the variations in the arrangements are explained in detail below.

1. Front engine – rear wheel drive

01 - TYPES OF WHEEL DRIVES - FRONT ENGINE REAR WHEEL DRIVE

Most of the vehicles are having this arrangement. In this case the engine power is transmitted to the vehicle rear wheels through the clutch, gear box, propeller shaft, differential and rear axle. The main advantages are better cooling is achieved, since steering and drive are independent, it is easy for construction and vehicle controlling is easy. With this arrangement, a uniform load distribution can be assured between the axles, but a long universal joint shaft is required. Because of the propeller shaft floor level will be increased, thereby the centre of gravity increases and the vehicle stability is poor.

2. Front engine – front wheel drive

01 - TYPES OF WHEEL DRIVES - FRONT ENGINE FRONT WHEEL DRIVE

Most of the modern cars are having this arrangement. In this case, the engine power is transmitted to the front wheels through the clutch, gear box, differential and short axle shafts. With this arrangement, a more compact transmission is obtained because the universal joint long propeller shaft drive is no longer necessary and the clutch and the gearbox are combined with the driving axle. The other advantages are: better cooling is achieved, better vehicle control, since the centre of gravity will be lowered resulting in more stability. However, it is difficult to provide both steering and power drive.

3. Rear engine-rear wheel drive

01 - TYPES OF WHEEL DRIVES - REAR ENGINE REAR WHEEL DRIVE

Some cars do have this arrangement. In this case, the engine power is transmitted to the rear wheels through the clutch, gear box, differential and short axle shafts. With this arrangement, outlet of exhaust is easy, streamlined motion is achieved in the front. This arrangement allows a better view of the road and reliably separates the engine from the passengers. This aspect reduces the noise and penetration of the exhaust gases into the saloon. The main difficulty of this layout is the complicated control of the engine, gearbox and clutch, since they are positioned far from the driver. Besides, with this layout, the driver and the front passenger sit near the front of the vehicle and in the case of collision or striking an obstacle they may be severely injured. Further engine cooling becomes a problem. Less stability especially when the vehicle moves along a gradient.

4. Four Wheel drive

01 - TYPES OF WHEEL DRIVES - FOUR WHEEL DRIVE

Some of the cross country vehicles have this arrangement. In this case, the engine power is transmitted to all the four wheels of the vehicle. The main advantage of this arrangement is the entire vehicle weight is available for traction. This arrangement however involves additional cost.

Fuel Feed System of Carburetor Engines | Carburetor Fuel Feed System

Carburetor: Carburetion is the process of measuring, mixing and supplying to a spark ignition engine continuously a suitable combustible mixture of fuel and air. This mixture supply must be in accordance with the engine speed and load requirements. The carburetor supplies this mixture to an engine. The carburetor consists basically of a float chamber and a metering cum mixing chamber.

Fuel feed system of carburetor engines

01 - Carburetor parts - Fuel feed system of carburetor engines

The preparation of air fuel mixture and its supply to the cylinders of the carburetor engine, the adjustment of its quality and quantity are accomplished by the fuel feed system. The feed system operation has a large effect on all the principal engine parameters. Therefore, necessary care must be taken to keep this system in proper working order during the engine use.

The system has a storage tank with fuel level amount sensing element, fuel gauge, filter, pump for supplying fuel from tank to carburetor. The fuel tank cap is vented. The atmospheric air enters the carburetor via air filter which acts at the same time as an intake silencer. From the carburetor, the fuel air mixture is supplied to the cylinder via intake duct.

Fuel gauge

01 - Carburetor parts - Fuel gauge of a carburetor

An electric gauge with balanced coils is used in many cars for indicating the quantity of fuel available in the fuel tank. The gauge is mounted on the instrument panel in front of the driver. This type of electric fuel gauge consists of two units a dash unit and a tank unit.

Fuel strainer

Some of the fuel tanks include a fuel filter at their exit or a sump at the bottom, to collect dirt and water and prevent them from reaching the pump and carburetor. Some tank are provided with a drain plug on the bottom for emptying the tank. Fuel tanks are often provided with vertical baffles to prevent surging of the fuel.

01 - Carburetor parts -  Ceramic fuel strainer

An additional fuel strainer is usually placed in the fuel line either before the pump as shown in the picture or after pump to filter gasoline before it enters the float chamber. The unit serves to catch any water or foreign particles that were not filtered out previously, in the fuel tank filter unit. One type of filter is shown in the picture. The fuel that enters into the glass bowl, passes through a ceramic filter to reach the inside section that is connected with the exit. The water and sediment are collected in the bowl which is made removable for cleaning.

Some engines use a disposable fuel filter in the fuel feed system. The entire unit may be replaced whenever it becomes inoperative, simply by loosening snap clamps.