torquelimiters

A torque limiter is a mechanical device placed in a drive train to restrict the amount of torque transmitted from a motor or engine to the driven load. Its purpose is to protect components such as gears, shafts, bearings, and couplings from overload by preventing torque from exceeding a preset value. Under normal operation, the device passes torque as designed; when the torque threshold is reached, the mechanism slips, disengages, or reduces the transmitted torque to protect the system.

Common implementations include friction-based slip torque limiters, where preloaded friction surfaces begin to slip at the set torque, and sprag or roller torque limiters that allow engagement up to a limit and then permit controlled slip. Some systems employ magnetic or electronically controlled mechanisms to limit torque, particularly in precision or high-speed applications. In many configurations, the limiter acts as a clutch that disengages at overload, while in others it provides a controlled amount of slip to allow continued motion with reduced torque.

Applications span various industries and equipment, including machine tools, conveyors, winches, cranes, drilling rigs, robotics, automotive drivetrains, and power tools. Designers must select an appropriate torque threshold, taking into account operating speed, temperature, wear, lubrication, and duty cycle. Calibration and periodic verification are typically required to ensure the device functions as intended over time.

Maintenance considerations include inspecting friction surfaces for wear, ensuring proper lubrication, checking alignment and mounting, and replacing worn components. While torque limiters enhance protection and safety, they can introduce additional wear, noise, or occasional jerky disengagement, depending on construction and operating conditions. The choice of a torque limiter is driven by the balance between protection needs, performance requirements, and maintenance capabilities.