Patent ID: 8425333
Filing Date: 2013-04-23
Classification: F16D

Abstract:
1. A torque limiter comprising: an outer annular member; an inner ring inserted in and rotatably supported by the outer annular member; a coil spring fitted around a radially outer surface of the inner ring with an interference fit; and a lid member fitted to a radially inner surface of the outer annular member at a first end thereof, thereby closing a gap between the radially inner surface of the outer annular member and the radially outer surface of the inner ring; wherein the coil spring has first and second cut end surfaces which are engageable with the outer annular member and the lid member, respectively, whereby a predetermined torque is generated due to radial expansion of the coil spring when the outer annular member and the inner ring rotate relative to each other; wherein both of the first and second cut end surfaces of the coil spring are radially outwardly spaced apart from the radially outer surface of the inner ring with the coil spring fitted on the inner ring; wherein the outer annular member has a radially inwardly protruding boss portion at a second end of the outer annular member, the boss portion having a radially inner surface rotatably supporting a second end of the inner ring, and a first spring receiving protrusion provided on the radially inner surface of the outer annular member at the second end thereof and formed with a first circumferentially opening recess that opens circumferentially to circumferentially receive the first cut end surface of the coil spring; wherein the lid member has a second spring receiving protrusion provided on an axially inner surface of the lid member and formed with a second circumferentially opening recess that opens circumferentially to circumferentially receive the second cut end surface of the coil spring; and wherein the first and second cut end surfaces of the coil spring are engageable in the first and second circumferentially opening recesses, respectively.