Edited by Mike Santora
The importance of a coupling’s duty cycle is sometimes overlooked specifically because it should go without saying. With certain types of motion: continuous, start stop, reversing- engineers must look at a coupling’s static torque number, take it into consideration, and then de-rate it.
For example, how often a system is running is always a consideration. Failures often occur when the type of motion is not accounted for or the number of cycles is not understood. For example, indexing. You know you’ve got an application where you’re indexing, the coupling is not actually making a full rotation but it could be indexing at a high rate. That environment puts a high amount of stress on a coupling and it’s not going to last forever just because you’re not rotating it at a higher RPM.
The duty cycle’s for certain jaw coupling applications are another good example. You’ve got a hard stop, hard start, very aggressive motion profile. For that type of an application, a curve jaw coupling is a good choice typically. It will protect the bearings in your motor and the bearings in your actuator from that shock. It will also extend your component life and if you’ve got a gradual start/stop application, slowly coming to a stop or reversing, at that point a beam coupling might work or an oldham coupling. The aggressiveness of the application demands is definitely a factor in choosing whether you want to use a jaw coupling or something different.