Clutch Alignment Specifications
One Way Clutch Types and Applications
Over-running clutches are also known as freewheeling or one-way clutches. The two types, usually used in machinery, are the sprag type and the roller-ramp type. The principle underlying the operation of both types is the wedging of an engaging element between an inner and an outer member. The figures show that as the outer race moves in the direction shown, the engaging element, be it roller or sprag, is caused to wedge between the members. The torque capacity is normally limited only by the contact stresses between the parts.
The heaviest duty, most sophisticated, and most expensive type is the sprag clutch. It has high ultimate torque capacity mainly because a large number of engaging elements are possible. Frequently, however, the torque rating of a sprag clutch is greater than the torsional strength of its maximum bore shaft. Often when the shaft size is determined by other factors such as beam loading, vibration, deflection, etc., the resulting sprag clutch is much too big.
Our roller ramp clutch was designed to compete in the applications involving the huskier shafts. Our usual four roller clutch balances the contact stresses between the roller and the ramp with the torsional shearing stresses in the shaft. This results in an easy-to-produce and simple device, which can really save our customers money in the majority of one-way clutch applications.
