Torque limiter

Abstract

A torque limiter comprises a driving member and a driven member disposed concentrically with the former. A drive-transmitting body made fast on the driving member has on its outer periphery several radial grooves which, in turn, hold torque-transmitting rollers of a size adapted to fit in the grooves. The upper and lower peripheral surfaces of the rollers are kept in pressure contact with the under end surface of a torque-transmitting-roller-supporting ring above the drive-transmitting body and with arcuate recesses formed on the upper surface of a driven member which is revolvably supported on the upper end surface of the lower portion of the driving member through a thrust bearing ring. A torque-spring-supporting sleeve is threadedly engaged with the outer periphery of the upper mounting portion of the driving member and is loaded with elastic pressure means in the form of torque springs. As long as the torque being applied to the limiter is below a predetermined critical level, the elastic pressure means press the torque-transmitting rollers through the supporting ring agaisnt the driven member, whereby the driving and driven members are driven together. If a more-than-critical torque is applied between those members, the torque-transmitting rollers urged against the arcuate recesses of the driven member will move away from the recesses, overcoming the elastic pressure means and thereby allowing the two members to run relative to each other.