Centrifugal clutches work as a soft start clutch or load-free start-up coupling, making it possible to start the engine without load or to run it on idle speed. This characteristic is used effectively for drives that require a high starting torque. If the engine accelerates up to a predetermined, the clutch shoe connects to the drum and the driven unit is accelerated smoothly up to operating speed. This process is automatic; there is no need for manual switching.
The principle is used perfectly for combustion engines and electric motors and allows the designer to choose an engine that is adapted to the normal operating speed and not to the high starting torque. This results in a smaller and less expensive motor. The speed at which the clutch is turned on can often be determined by a simple spring change.