BELT AND CHAIN and gear DRIVES.pptx (Size: 3.8 MB / Downloads: 107)
Types of power transmission
Belt Transmission – the power is transmitted by using belts
Chain transmission - the power is transmitted by using chains
Gear transmission - the power is transmitted by using gears
A belt is a loop of flexible material used to link two or more rotating shafts mechanically
Belts may be used as a source of motion, to transmit power efficiently, or to track relative movement
Belts are looped over pulleys
In a two pulley system, the belt can either drive the pulleys in the same direction, or the belt may be crossed, so that the direction of the shafts is opposite
Types of belts
Flat belts were used early in line shafting to transmit power in factories.
They were also used in countless farming, mining, and logging applications, such as bucksaws, water pumps and electrical generator
Round belts are a circular cross section belt designed to run in a pulley with a circular groove
They are for use in low torque situations and may be purchased in various lengths or cut to length and joined, either by a staple, gluing or welding
Early sewing machines utilized a leather belt, joined either by a metal staple or glued, to a great effect.
Material used for Belts
Leather belts. The most important material for flat belt is leather.
The best leather belts are made from 1.2 metres to 1.5 metres long strips cut from either side of the back bone of the top grade steer hides
The belt and pulley and places the greatest tensile strength of the belt section on the outside, where the tension is maximum as the belt passes over the pulley.
The leather may be either oak-tanned or mineral salt-tanned e. g. chrome-tanned. In order to increase the thickness of belt, the strips are cemented together. The belts are specified according to the number of layers e.g. single, double or triple ply and according to the thickness of hides used e.g. light, medium or heavy.