Rotation transmission device

摘要

A rotation transmission device includes an outer ring having an inner cylindrical surface, and an inner ring having outer cam surfaces. A pair of rollers and an elastic member biasing the rollers away from each other are mounted between the cylindrical surface and each adjacent pair of the cam surfaces. The rollers and the elastic members are retained by a control retainer and a rotary retainer each having a flange and crossbars extending from the flange and circumferentially alternating with the crossbars of the other retainer. The respective opposed pairs of rollers are pushed by the respective crossbars to a disengaged position when the retainers rotate relative to each other. The crossbars of the retainers are disposed between the outer ring and the inner ring and the flanges are provided outside the outer ring to minimize the axial length of the outer ring.

主权项

1. A rotation transmission device comprising:
an outer ring having an inner periphery; an inner ring mounted in the outer ring and having an outer periphery, wherein a cylindrical surface is formed on one of the inner periphery of the outer ring and the outer periphery of the inner ring, and a plurality of pairs of circumferentially spaced apart cam surfaces are formed on the other of the inner periphery of the outer ring and the outer periphery of the inner ring, whereby wedge-shaped spaces are defined between the respective cam surfaces and the cylindrical surface; a plurality of opposed pairs of rollers received in the respective adjacent pairs of wedge-shaped spaces; elastic members disposed between the respective opposed pairs of rollers and biasing the respective opposed pairs of rollers away from each other; retainers retaining the rollers and comprising a control retainer and a rotary retainer, wherein each of the control retainer and the rotary retainer comprises a flange axially facing the flange of the other retainer, and a plurality of circumferentially spaced apart crossbars provided at an outer peripheral portion of the flange and arranged circumferentially alternating with the crossbars of the other retainer, whereby the respective adjacent pairs of crossbars define pockets, wherein each of the opposed pairs of rollers and each of the biasing members are mounted in each of the pockets; a torque cam provided between opposed surfaces of the flanges of the control retainer and the rotary retainer and configured to rotate the retainers relative to each other in a direction in which circumferential widths of the pockets decrease, when the control retainer is moved in a direction in which the distance between the flanges decreases; and an electromagnetic clutch mounted on an input shaft supporting the inner ring and configured to axially move the control retainer, wherein the electromagnetic clutch comprises an armature supported so as to be movable in an axial direction of the input shaft, a rotor axially facing the armature, and an electromagnet axially facing the rotor and configured to attract the armature into contact with the rotor when the electromagnet is energized, wherein the armature is coupled to the control retainer so as to axially move the control retainer,
wherein the control retainer and the rotary retainer are mounted such that the crossbars are disposed between the outer ring and the inner ring and the flanges are disposed between the outer ring and the armature, wherein the armature has a coupling tube provided at an outer peripheral portion of the armature, wherein the control retainer has a tubular portion provided at an outer peripheral portion of the flange of the control retainer and press-fitted in or on the coupling tube of the armature, and wherein the input shaft has a first slide guide surface movably supporting a radially inner surface of the armature, and a second slide guide surface movably supporting a radially inner surface of the flange of the control retainer.