Shaft Coupling

Coupling Application Considerations When selecting a flexible coupling, several application conditions exist which should be looked at when making your selection. Torque and Horsepower The strength of a coupling is defined as its ability to transmit a required torque load, frequently in combination with other factors. Hence a coupling may be selected whose rated torque capacity is many times greater than needed. Shaft Misalignment Shaft misalignment can be due to unavoidable tolerance build-ups in a mechanism or intentionally produced to fulfill a specific function. Lateral and Axial Flexibility of Couplings Forces are needed to make a flexible coupling flex. These forces are either lateral or axial in nature or a combination of both. Universal joints and Oldham couplings impose relatively little lateral load on bearings. Small lateral force calls for soft rubber and in turn reduces torque capacity. Torsional Flexibility Torsional flexibility of a coupling is the elastic deformation induced in aflexible coupling while transmitting torque. Backlash Backlash is the amount of rotational play when some flexible couplings are used in bi-directional drives. Rotational Velocity Error If the input speed into a single universal joint is held constant, then the output will produce cyclic fluctuations in direct relation to the operating angles of the input and output shafts. Service Conditions Service conditions include factors such as temperature, operating medium, lubrication, accessibility for maintenance and should be reviewed before a final selection is made.