Torque Limiter

A torque limiter is an automatic device that protects mechanical equipment, or its work, from damage by mechanical overload.
A torque limiter may limit the torque by slipping (as in a friction plate slip-clutch), or uncouple the load entirely (as in a shear pin).
The action of a torque limiter is especially useful to limit any damage due to crash stops and jams.
Torque limiters may be packaged as a shaft coupling or as a hub for sprocket or sheave.
A torque limiting device is also known as an overload clutch.