Tech Tip: What I would do in a continuously cycling application is calculate the RMS torque of the load cycle and then pick a gearmotor with a continuous rating that meets or exceeds that RMS torque. Or, if there are size or cost constraints that limit the gearmotor selection, I might choose the largest gearmotor within the size/cost budget and then advise the conveyor designer on the maximum start/stop frequency to advertise for his/her system. And then there’s other considerations for specific motor types, like the centrifugal start switch in split phase motors that isn’t designed for frequent start/stop operation.

Comment #2: What if the gearmotor is not directly coupled to the conveyor, and the design requires a chain or timing belt?

Tech Tip: Chain and belt drives are so common on conveyors that it probably should have been included even in this “basic” reference. The calculation is actually quite simple. If the speed reduction of the chain or belt drive is N:1, then the gearmotor output speed should be N times the speed calculated for the conveyor roller and the torque output should be 1/N times the torque calculated for the conveyor roller.