Mechanical energy transmission system

Belt Drives

Belts and chains are also used to transmit mechanical power like gears.

Belts and Pulleys

Belts and pulleys are used to transmit power and to provide a way of changing speeds. The simplest belt-driven device is two pulleys connected with a belt.

Simple belt pulley drive

A pulley mounted on the shaft of an engine is the driver pulley. Driven pulleys are belted to the driver pulleys to operate small machines like the pulley in a pepper-grinding machine. In pulleys, the relationship between size and speed and between the driver and the driven is same as for gears. Try to observe the belt and pulleys used in a pepper grinding grinders.

Kinds of Belts and Pulleys

There are three kinds of belts and pulleys in common use. They are flat belts and pulleys, vee belts and pulleys and variable speed pulleys which use vee belts also. With a variable speed between the driver and the driven without stopping the engine. In fact, the speed should be changed only when the engine is running.

A common example of the use of chain drive in transmission of power is found in bicycles and motorcycles. Thus, in a bicycle, the power being applied on the pedals by the rider is transmitted to the back wheel by means of a chain linked to two gears. The chain drive has a major advantage over a belt drive. The belt slips in the event of an excessive load, but the chain does not. For this reason, the chain can drive for a much longer period of time than the belt without attention, provided the chain and the gears are well lubricated. The speed ratio between the shafts of a chain drive depends on the number of teeth in each of the gears or chain wheels \9as they are often called) used. They are determined in the same way as we discussed for pulleys.