A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Couplings do not normally allow disconnection of shafts during operation, however there are torque limiting couplings which can slip or disconnect when some torque limit is exceeded.
The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment or end movement or both. By careful selection, installation and maintenance of couplings, substantial savings can be made in reduced maintenance costs and downtime.
Mild steel or wrought iron shaft are available in lengths varying from 6 to 10 meters, so as to make them handy and easy to transport. More lengthy shafts cannot be manufactured in a correct form to be used for power transmission. In engineering practice shafts of large lengths are required to transmit the torque which can be obtained by joining two or more shafts in order to obtain the required length. The joining of shafts is done by device is called as coupling.
Tyre coupling is used to connect two shafts which are parallel & and it will make up the Miss alignment and withstand the backlash. HIGH MISALIGNMENT TOLERANCE of one degree per end can be tolerated without damage to the drive shaft or connected equipment bearings. Tyre coupling are made from high strength composite materials. It is mainly used in the Automobile Dry Shaft power Transmission.
REQUIREMENTS OF A GOOD SHAFT COUPLING:
1. It should be easy to connect or disconnect.
2. It should transmit the full power from one shaft to other shaft without losses. 3. It should hold the shafts in perfect alignment.
4. It should reduce the transmission of shock loads from one shaft to another shaft.