Rotation transmission device

Patent metadata

Field	Value
Publication number	US-9103384-B2
Application number	US-201213980081-A
Country	US
Kind code	B2
Filing date	Jan 20, 2012
Priority date	Jan 21, 2011
Publication date	Aug 11, 2015
Grant date	Aug 11, 2015

Abstract

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.

First claim

What is claimed is:

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.

2. The rotation transmission device of claim 1 , wherein the input shaft is made of a non-magnetic metal.

3. The rotation transmission device of claim 1 , wherein the input shaft includes a non-magnetic metal ring supporting the armature, and wherein the slide guide surface movably supporting the armature is formed on an outer periphery of the non-magnetic metal ring.

4. The rotation transmission device of claim 1 , wherein the input shaft includes a resin ring supporting the armature, and wherein the slide guide surface movably supporting the armature is formed on an outer periphery of the resin ring.

5. The rotation transmission device of claim 4 , wherein the resin ring is made of a self-lubricating resin.

6. The rotation transmission device of claim 1 , wherein the elastic members comprise coil springs having a rectangular section.

7. The rotation transmission device of claim 6 , wherein the inner ring has flat spring support surfaces on the inner periphery thereof which support long sides of the respective elastic members.

8. The rotation transmission device of claim 1 , wherein the elastic members comprise coil springs having an elliptical section.

9. The rotation transmission device of claim 8 , wherein the inner ring has flat spring support surfaces on the inner periphery thereof which support long sides of the respective elastic members.

10. The rotation transmission device of claim 1 , further comprising a housing covering the outer ring and the electromagnetic clutch and having a closed first end formed with a bearing tube, an output shaft rotatably supported by the bearing tube, and a dust cover comprising a disk portion axially facing an end surface of the bearing tube, and a tubular portion provided at an outer peripheral portion of the disk portion and covering an outer periphery of the bearing tube, wherein the electromagnet of the electromagnetic clutch is fitted in an opening of the housing at a second end of the housing such that the electromagnet serves as a cover for the housing.

11. The rotation transmission device of claim 10 , wherein the electromagnet comprises an electromagnetic coil and a core supporting the electromagnetic coil, and wherein an anti-rotation groove is formed in one of a radially outer surface of the core and a radially inner surface of the housing near the opening of the housing, and a protrusion is formed on the other of the radially outer surface of the core and the radially inner surface of the housing near the opening of the housing such that the protrusion is engaged in the anti-rotation groove, thereby preventing rotation of the electromagnet.

Assignees

• Akiyoshi Koji
• Saito Takahide
• Ntn Toyo Bearing Co Ltd

Inventors

• Akiyoshi Koji
• Saito Takahide

Classifications

• F16D15/00 Primary

  Clutches with wedging balls or rollers or with other wedgeable separate clutching members (freewheels, freewheel clutches F16D41/00) · CPC title

• F16D41/105

  the intermediate members being of circular cross-section, of only one size and wedging by rolling movement not having an axial component between inner and outer races, one of which is cylindrical · CPC title

• F16D27/102

  with radially movable clutching members (F16D27/105 takes precedence) · CPC title

• F16D27/112 Primary

  with flat friction surfaces, e.g. discs · CPC title

• F16D41/088

  the intermediate members being of only one size and wedging by a movement not having an axial component, between inner and outer races, one of which is cylindrical · CPC title