TORQUE LIMITER

PROBLEM TO BE SOLVED: To make the limit driving torque variable by providing an outer case with an electromagnet, and changing the magnetic force of this electromagnet. SOLUTION: In comparison with a conventional torque limiter, an electromagnet 5 is arranged in an outer wall surface of an outer case 1. In place of a magnet fitted to a shaft 2 in a conventional device, a ring-like magnetic element 3 is fitted. As this magnetic element 3, any one of a magnetized element and a non-magnetized element can be used. Furthermore, a magnetic element provided in the inner wall surface of the outer case 1 in the conventional one is eliminated. Principle of a device that the electromagnet 5 is electrified for excitation is the same with the conventional one. In this torque limiter, the force between the magnetic powders filled in the outer case can be desirably changed by changing the magnetic force of the electromagnet. As a result, the limit driving torque by a torque limiter function can be freely changed.