JP2009008169A - Rotation transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation transmitting device which can suppress an air gap variation between opposite faces of a rotor and an armature, and surely make the armature stick to the rotor by energizing an electromagnetic coil of an electromagnet. <P>SOLUTION: A two-way clutch 10 is incorporated between the outer ring 1 and the inner ring 2, and an electromagnetic clutch 20 is arranged simultaneously. Furthermore, the electromagnetic clutch 20 is formed by an armature 21 axially movable, a rotor guide 22, a rotor 23, an electromagnet 24, and an estrangement spring 25 biasing the armature 21 in a direction being estranged from the rotor 23. Additionally, a pair of bearings 30a and 30b is interfit into an input shaft 4, which is coaxially arranged with the inner ring 2, and integrally rotates, and supports it to be axially non-movable, furthermore the rotor 23 is rotatably supported with the pair of bearings 30a and 30b, and a variation of air gap g formed between opposite faces of the rotor 23 and the armature 21 is made to be small. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotation transmission device used for switching between power transmission and cutoff on a power transmission path.

  In an FR-based four-wheel drive vehicle, a rotation transmission device that transmits and interrupts driving force to a front wheel as an auxiliary drive wheel has been conventionally known.

  In the rotation transmission device described in Patent Document 1, a two-way clutch is incorporated between a large-diameter portion formed on the input-side member and an outer ring provided on the outside thereof, and an electromagnetic clutch attached to the two-way clutch is used. By controlling the engagement and disengagement of the two-way clutch, the input side member and the outer ring are coupled by the engagement of the two-way clutch, and rotational torque is transmitted between the input side member and the outer ring. Yes.

  Here, the two-way clutch forms a cylindrical surface on the inner periphery of the outer ring, and forms a wedge-shaped space in which both ends in the circumferential direction are narrow between the cylindrical surface and the outer periphery of the large-diameter portion of the input side member. A cam surface is provided, and an engaging element made of a roller is incorporated between the cam surface and the cylindrical surface, and the engaging element is engaged with the cylindrical surface and the cam surface by the relative rotation of the cage that holds the engaging element and the input side member. I try to let them. Further, a switch spring is incorporated between the input side member and the cage, and the cage is elastically held at a neutral position where the engagement element is disengaged from the cylindrical surface and the cam surface by the switch spring.

  On the other hand, an electromagnetic clutch is an armature that is prevented from rotating by a cage and supported so as to be movable in the axial direction, a rotor that is connected to an outer ring and faces the armature in the axial direction, and an electromagnet that faces the rotor in the axial direction And a separation spring that urges the armature in a direction away from the rotor.When the electromagnet is energized, the armature is attracted to the rotor, and the armature coupled to the outer ring is rotated relative to the input member to engage the engagement element. It is made to engage with a cylindrical surface and a cam surface.

  Here, if the axial air gap formed between the facing surfaces of the armature and rotor becomes too large, the armature cannot be attracted even if the electromagnet is energized. It is necessary to position the rotor in the axial direction so that a large air gap is formed.

JP 2005-249003 A

  By the way, in the rotation transmission device described in Patent Document 1, the first cylindrical portion and the second cylindrical portion are provided from the tip at the opening end portion of the outer ring, and a cylindrical rotor guide is fitted into the first cylindrical portion. In this configuration, the rotor is fitted into the rotor guide and positioned so that there is a large variation in the axial air gap formed between the rotor and the armature due to the accumulation of dimensional tolerances of each part. There was a point to be improved.

  An object of the present invention is to ensure that the armature is attracted to the rotor by energizing the electromagnetic coil of the electromagnet so that the variation in the air gap formed between the opposed surfaces of the rotor and the armature can be suppressed to a small range. An object of the present invention is to provide a rotation transmission device that can be used.

  In order to solve the above-described problems, in the present invention, an engaging element and a retainer for retaining the engaging element are provided between the outer ring and the inner ring incorporated inside the outer ring, and the engagement is controlled by controlling the rotation of the retainer. An electromagnetic that controls the engagement and disengagement of the two-way clutch by incorporating a two-way clutch that couples the outer ring and the inner ring by engaging the joint with the opposing surfaces of the outer ring and the inner ring. An annular armature provided with a clutch, the electromagnetic clutch of which is prevented from rotating with respect to the cage and supported so as to be movable in the axial direction, and a cylinder which is fitted to the opening end of the outer ring and is prevented from rotating. Rotor guide, a rotor incorporated in the rotor guide and opposed to the armature in the axial direction, a separation spring for biasing the armature in a direction away from the rotor, and the rotor and the axial direction An end portion on the inner side adjacent to the armature of the rotor on a rotation shaft that is arranged coaxially with the inner ring and rotates integrally with the inner ring, in the rotation transmission device that opposes and energizes the armature by attracting the armature to the rotor And a pair of bearings that support the outer side end portions and are supported in a non-movable manner in the axial direction, and positioning means for positioning the rotor in the axial direction is provided between the pair of bearings and the rotor. A configuration is adopted in which the guide and the outer ring are slidably fitted in the axial direction, and a large-diameter portion for restricting the armature separation position is provided on the outer periphery of the rotating shaft.

  Here, by forming a guide tube that is slidably fitted to the outer peripheral surface of the rotating shaft on the inner peripheral portion of the armature so as to face the bearing side, the posture of the armature is stabilized, and between the opposing portion of the rotor and the armature In addition, an air gap having a uniform size can be formed over the entire circumferential direction.

  In the rotation transmission device according to the present invention, as support means for supporting the pair of bearings in a non-movable manner in the axial direction, positions facing the inner side surface of the inner side bearing and the outer side surface of the outer side bearing on the outer periphery of the rotary shaft It is possible to adopt a configuration in which an engaging groove is formed in each of the engaging grooves, a retaining ring is attached to each engaging groove, and a pair of bearings are pressed against the retaining ring by a spacer installed between the opposing surfaces. .

  In this case, the outer surface of the outer side retaining ring that supports the outer side bearing non-movably in the axial direction is a tapered surface whose inner diameter portion is thinner than the outer diameter portion, and the retaining ring is engaged. By making the outer surface of the mating groove into a tapered surface that matches the tapered surface of the retaining ring, the retaining ring moves in the axial direction by contact between the tapered surfaces when the retaining ring is attached to the engaging groove, and the outer side bearing Is pressed toward the inner bearing, so that the pair of bearings can be supported without play in the axial direction.

  Here, by positioning the inner bearing with the large-diameter portion formed on the outer diameter surface of the rotating shaft, the retaining ring can be omitted, so that the cost can be reduced.

  In the rotation transmission device according to the present invention, the support rigidity of the rotor can be increased by providing preload applying means for applying a preload to the outer side bearing. As the preload applying means, it is possible to adopt a configuration in which an elastic member such as a wave spring is incorporated between the inner ring and the retaining ring of the outer side bearing and the inner ring is pressed toward the inner side bearing.

  In the rotation transmission device according to the present invention, as a positioning means for the rotor, an inward flange facing the inner side surface of the inner bearing in the axial direction is provided on the inner diameter surface of the inner end portion of the rotor close to the armature, and the rotor An engagement groove is formed on the inner diameter surface of the outer end portion of the outer end bearing so as to face the outer surface of the outer side bearing, and a pair of bearings are attached to both sides in the axial direction by a retaining ring attached to the engagement groove and the flange. What consists of the structure clamped can be employ | adopted.

  In this case, the outer surface of the retaining ring is a tapered surface with the outer diameter portion of the retaining ring being thinner than the inner diameter portion, and the outer surface of the engaging groove with which the retaining ring is engaged is adapted to the tapered surface of the retaining ring. By attaching the retaining ring to the engagement groove, the retaining ring moves in the axial direction by contact between the tapered surfaces and sandwiches the pair of bearings from both sides in the axial direction with the flange. Therefore, the rotor can be positioned with high accuracy in the axial direction.

  As described above, in the present invention, a pair of bearings are fitted to the rotating shaft that rotates integrally with the inner ring, and is supported in a non-movable manner in the axial direction, and the rotor is rotatably supported by the bearings in the axial direction. A conventional rotation transmission device that positions and positions the rotor guide with respect to the outer guide by positioning the rotor guide with respect to the outer ring by regulating the separation amount of the armature by the large-diameter portion formed on the outer periphery of the rotating shaft. In comparison, the accumulation of dimensional tolerances is small, and an axial air gap with little variation can be formed between the opposed portions of the rotor and the armature, and the armature can be reliably attracted to the rotor by energizing the electromagnet.

  In addition, the inner end and the outer end of the inner diameter surface of the rotor are rotatably supported by a pair of bearings, so that the rotor can be held coaxially with the rotating shaft, and between the opposing portions of the rotor and the armature In addition, an air gap having a uniform size can be formed over the entire circumferential direction.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an inner ring 2 is incorporated inside the outer ring 1, and the outer ring 1 and the inner ring 2 are supported relatively rotatably by a bearing 3.

  An input shaft 4 as a rotation shaft is inserted inside the inner ring 2, and the input shaft 4 and the inner ring 2 are prevented from rotating by a serration 5 so that the input shaft 4 and the inner ring 2 rotate integrally.

  A two-way clutch 10 is incorporated between the outer ring 1 and the large-diameter portion 2 a formed on the inner ring 2. As shown in FIG. 2, the two-way clutch 10 forms a cylindrical surface 11 on the inner periphery of the outer ring 1, and both ends in the circumferential direction between the outer surface of the large-diameter portion 2 a of the inner ring 2 and the cylindrical surface 11. Flat cam surfaces 12 forming a narrow wedge-shaped space are provided at intervals in the circumferential direction, and an engagement element 13 made of a roller is incorporated between each cam surface 12 and the cylindrical surface 11, and the engagement element 13 is held in a cage. 14 is held.

  In addition, a switch spring 15 partially cut off in the circumferential direction is incorporated in the end portion of the inner ring 2, and a pair of pressing pieces 15 a formed outward from both ends of the switch spring 15 are formed on the end surface of the inner ring 2. It inserts into the notch 17 provided in the edge part of the holder | retainer 14 from the notch part 16, presses the opposing side surface in the circumferential direction of the notch part 16 and the notch 17 in the opposite direction, and the engagement element 13 is pressed by the pressing. Holds the retainer 14 in a neutral position where the engagement is released from the cylindrical surface 11 and the cam surface 12.

  As shown in FIG. 1, an electromagnetic clutch 20 that controls the engagement and disengagement of the two-way clutch 10 is provided between the outer ring 1 and the cage 14 together with the two-way clutch 10. Yes.

  The electromagnetic clutch 20 is incorporated in an armature 21 disposed opposite to the end face of the cage 14, a cylindrical rotor guide 22 connected to the open end of the outer ring 1 and covering the armature 21, and the rotor guide 22. A rotor 23 that is axially opposed to the armature 21, an electromagnet 24 that is axially opposed to the rotor 23, and a separation spring 25 that biases the armature 21 in a direction away from the rotor 23.

  As shown in FIG. 3, the armature 21 is fitted to the input shaft 4 and slidably supported. The armature 21 has an engagement hole 26, and a projection piece 27 formed at the end of the retainer 14 is engaged with the engagement hole 26, and the armature is engaged by the engagement of the projection piece 27 and the engagement hole 26. 21 is prevented from rotating with respect to the retainer 14 and is movable in the axial direction.

  The armature 21 is pressed against the large-diameter portion 4a formed on the outer periphery of the input shaft 4 by the pressing of the separation spring 25, and the separation position is regulated.

  The rotor guide 22 is made of a nonmagnetic material. The rotor guide 22 is fitted to the outer periphery of the opening end portion of the outer ring 1, is prevented from rotating on the outer ring 1 by a spline 28 formed between the fitting surfaces, and is slidable in the axial direction.

  The rotor 23 has cylindrical portions 23 a and 23 b facing in the same direction on the outer periphery and the inner periphery, and the outer cylindrical portion 23 a is press-fitted into the rotor guide 22 to prevent rotation, and a shoulder formed on the inner periphery of the rotor guide 22. Positioned in the axial direction by a retaining ring 29 attached to the inner periphery of the opening end of the portion 22 a and the rotor guide 22.

  On the other hand, the inner cylindrical portion 23b is rotatably supported at the inner end portion and the outer end portion close to the armature 21 by a pair of bearings 30a and 30b fitted to the outer periphery of the input shaft 4.

  The inner side bearing 30a that supports the inner side end portion of the rotor 23 and the outer side bearing 30b that supports the outer side end portion are non-movable supports in the axial direction. Here, when supporting the bearings 30 a and 30 b, a pair of engagement grooves 33 are formed on the outer periphery of the input shaft 4, a retaining ring 31 is attached to each engagement groove 33, and the inner bearing 30 a is interposed between the retaining rings 31. And the outer side bearing 30b and a spacer 32 between the bearings 30a and 30b, the inner side surface of the inner side bearing 30a is pressed against the retaining ring 31, and the outer side surface of the outer side bearing 30b is retained with the retaining ring 31. And the bearings 30a and 30b are used as non-movable supports in the axial direction.

  The rotor 23 is positioned in the axial direction with respect to the pair of bearings 30a and 30b. Here, as the positioning means, an inward flange 34 that is axially opposed to the inner side surface of the inner bearing 30a is formed on the inner diameter surface of the inner end portion of the inner cylindrical portion 23b adjacent to the armature 21, and the inner cylindrical portion An engagement groove 35 is provided at a position facing the outer surface of the outer bearing 30b on the inner diameter surface of the outer end portion 23b, and a pair of bearings 30a is formed by a retaining ring 36 attached to the engagement groove 35 and the flange 34. 30b is sandwiched from both sides to position the rotor 23 in the axial direction.

  The electromagnet 24 includes an electromagnetic coil 24a and a fixedly arranged core 24b that supports the electromagnetic coil 24a. When the electromagnetic coil 24a is energized, magnetic flux flows through the core 24b, the rotor 23, and the armature 21, and is attracted to the armature 21. Power is given.

  The rotation transmission device shown in the embodiment has the above-described structure, and FIGS. 1 and 3 show a cut-off state of the electromagnet 24 with respect to the electromagnetic coil 24a. The armature 21 is separated from the rotor 23 and An air gap g in the axial direction is formed between the two. The two-way clutch 10 is in a disengaged state. For this reason, even if the inner ring 2 rotates, the rotation is not transmitted to the outer ring 1 and the inner ring 2 rotates freely.

  When the electromagnetic coil 24 a of the electromagnet 24 is energized while the inner ring 2 is rotating, magnetic flux flows between the core 23 b, the rotor 23, and the armature 21, and the armature 21 is attracted to the rotor 23.

  As the armature 21 is attracted, the frictional resistance acting on the attracting surface becomes the rotational resistance of the cage 14, so that the inner ring 2 and the cage 14 rotate relative to each other. By the relative rotation, the engaging element 13 is engaged with the cylindrical surface 11 and the cam surface 12, the two-way clutch 10 is engaged, and the rotation of the inner ring 2 is transmitted to the outer ring 1. Further, the switch spring 15 is elastically deformed by the relative rotation of the inner ring 2 and the cage 14.

  For this reason, when the energization to the electromagnetic coil 24a is interrupted, the armature 21 is separated from the rotor 23 by the pressing force of the separation spring 25, the cage 14 is rotated by the restoring elasticity of the switch spring 15, and the engaging element 13 is cylindrical. The two-way clutch 10 is disengaged from the neutral position where the engagement with the surface 11 and the cam surface 12 is released, and the rotation transmission from the inner ring 2 to the outer ring 1 is interrupted.

  As described above, the rotation transmission device attracts the armature 21 to the rotor 23 by energizing the electromagnetic coil 24a of the electromagnet 24 to bring the two-way clutch 10 into the engaged state. If the formed air gap g becomes larger than necessary, the armature 21 cannot be attracted and the two-way clutch 10 cannot be operated reliably.

  As shown in the embodiment, a pair of bearings 30a and 30b fitted to the outer periphery of the input shaft 4 are supported non-movably in the axial direction by a pair of retaining rings 31 attached to the outer periphery of the input shaft 4, and the rotor 23 A pair of bearings 30a and 30b are sandwiched from both sides by a flange 34 formed on the inner periphery of the inner end of the inner ring and a retaining ring 36 attached to the inner periphery of the outer end to position the rotor 23 in the axial direction; By restricting the separation position of the armature 21 by the large-diameter portion 4a formed on the input shaft 4, an air gap g having an appropriate size with small variations can be secured between the opposed surfaces of the rotor 23 and the armature 21. .

  For this reason, the armature 21 can be reliably adsorbed to the rotor 23 by energizing the electromagnetic coil 24a.

  Further, the rotor 23 can be held coaxially with the input shaft 4 by rotatably supporting the rotor 23 by the pair of bearings 30a and 30b. For this reason, an air gap g having a uniform size can be formed across the entire circumferential direction between the facing surfaces of the armature 21 and the rotor 23 slidably supported by the input shaft 4, and the rotor is energized by energization of the electromagnetic coil 24a. The armature 21 can be more reliably adsorbed to 23.

  FIG. 4 shows another example of the armature 21. In this example, a guide tube 40 that is slidably fitted to the outer diameter surface of the input shaft 4 is provided on the inner peripheral portion of the armature 21, and the armature 21 is in a state where the separation position is regulated by the large diameter portion 4a. The axial gap s between the guide ring 40 and the retaining ring 31 that engages with the inner surface of the inner bearing 30 a is made larger than the axial air gap g formed between the opposing surfaces of the armature 21 and the rotor 23.

  As described above, by providing the guide tube 40 that is slidably supported by the input shaft 4 on the inner peripheral portion of the armature 21, the posture of the armature 21 is stabilized, and the circumferential direction is provided between the rotor 23 and the facing portion of the armature 21. An air gap having a uniform size can be formed throughout.

  FIG. 5 shows another example of a support device for supporting the bearings 30a and 30b in a non-movable manner in the axial direction and positioning means for positioning the rotor 23 in the axial direction. In this example, the outer surface of the outer side retaining ring 31 that supports the outer side bearing 30b in a non-movable manner in the axial direction is a tapered surface 31a in which the inner diameter portion of the retaining ring 31 is thinner than the outer diameter portion. The outer surface of the engagement groove 33 with which the ring is engaged is a tapered surface 33 a that fits the tapered surface 31 a of the retaining ring 31.

  Further, the outer surface of the retaining ring 36 for positioning the rotor 23 in the axial direction with the flange 34 is formed as a tapered surface 36a in which the outer diameter portion of the retaining ring 36 is thinner than the inner diameter portion, and the retaining ring 36 is engaged. The outer surface of the engagement groove 35 is a tapered surface 35 a that fits the tapered surface 36 a of the retaining ring 36.

  As described above, the retaining ring 31 is attached to the engaging groove 33 by attaching the retaining ring 31 to the engaging groove 33 by using the outer surface of the outer retaining ring 31 as the tapered surface 31a and the outer surface of the engaging groove 33 as the tapered surface 33a. Since the taper surfaces 31a and 33a move in the axial direction by the contact between the taper surfaces 31a and 33a and press the outer side bearing 30b toward the inner side bearing 30a, the pair of bearings 30a and 30b may be supported without play in the axial direction. it can.

  Further, the outer surface of the rotor positioning retaining ring 36 is a tapered surface 36a, and the outer surface of the engaging groove 35 with which the retaining ring 36 is engaged is a tapered surface 35a. By attaching 36, the retaining ring 36 moves in the axial direction by contact between the tapered surfaces 35a, 36a, and sandwiches the pair of bearings 30a, 30b from both sides in the axial direction with the flange 34. Positioning can be performed with high accuracy in the axial direction.

  FIG. 6 shows still another example of a support device that supports the bearings 30a and 30b in a non-movable manner in the axial direction. In this example, instead of the inner side retaining ring 31 shown in FIG. 3, a large diameter portion 4b is formed on the outer diameter surface of the input shaft 4 so as to face the inner surface of the inner bearing 30a in the axial direction. 4b supports the inner bearing 30a in a non-movable manner in the axial direction.

  As described above, the inner-side retaining ring 31 shown in FIG. 3 can be made unnecessary by forming the large-diameter portion 4b on the input shaft 4 and supporting the inner-side bearing 30a in a non-movable manner in the axial direction. Cost can be reduced.

  FIG. 7 shows still another example of a support device that supports the bearings 30a and 30b in a non-movable manner in the axial direction. In this example, the bearing support device shown in FIG. 3 is provided in that a preload is applied to the outer bearing 30b by incorporating an elastic member 41 made of a wave spring between the inner ring and the retaining ring of the outer bearing 30b. It is different.

  As shown in FIG. 7, the support rigidity of the rotor 23 can be increased by applying a preload to the outer side bearing 30b.

Longitudinal front view showing an embodiment of a rotation transmission device according to the present invention Sectional view along the line II-II in FIG. Sectional drawing which expands and shows a part of electromagnetic clutch part of FIG. Sectional view showing another example of armature Sectional drawing which shows the other example of a bearing support apparatus and a rotor positioning means Sectional drawing which shows the other example of a bearing support apparatus Sectional view showing still another example of bearing support device

Explanation of symbols

1 Outer ring 2 Inner ring 4 Input shaft (rotating shaft)
4a Large diameter portion 4b Large diameter portion 10 Two-way clutch 13 Engagement element 14 Cage 20 Electromagnetic clutch 21 Armature 22 Rotor guide 23 Rotor 24 Electromagnet 25 Release spring 30a Inner side bearing 30b Outer side bearing 31 Retaining ring 31a Tapered surface 32 Spacer 33 engagement groove 33a taper surface 34 flange 35 engagement groove 35a taper surface 36 retaining ring 36a taper surface 40 guide tube 41 elastic member

Claims (9)

Between the outer ring and the inner ring incorporated in the inner ring, there is an engagement element and a cage for holding the engagement element, and the engagement element is engaged with the opposing surfaces of the outer ring and the inner ring by controlling the rotation of the retainer. A two-way clutch for coupling the outer ring and the inner ring is incorporated, and an electromagnetic clutch for controlling the engagement and disengagement of the two-way clutch is provided along with the two-way clutch, and the electromagnetic clutch is attached to the retainer. A ring-shaped armature that is supported against rotation in the axial direction and is supported so as to be movable in the axial direction; a cylindrical rotor guide that is fitted to the opening end of the outer ring and is prevented from rotating; and is incorporated in the rotor guide. The rotor that is opposed to the armature in the axial direction, the separation spring that urges the armature in the direction away from the rotor, and the rotor that is opposed to the rotor in the axial direction and sucks the armature by energization. In the rotation transmitting device comprising a magnet for,
A pair of bearings supporting the inner side end and the outer side end close to the armature of the rotor are fitted in the axial direction on a rotating shaft that is arranged coaxially with the inner ring and rotates integrally with the inner ring. Positioning means for positioning the rotor in the axial direction is provided between the pair of bearings and the rotor so that the rotor guide and the outer ring are slidably fitted in the axial direction. Is a rotation transmission device provided with a large-diameter portion for regulating the armature separation position.   A guide tube that is slidable along the outer diameter surface of the rotating shaft is formed on the inner peripheral portion of the armature toward the bearing side, and the armature is in a state where the separation position is regulated by the large diameter portion. The rotation transmission device according to claim 1, wherein an axial gap formed between the opposing surfaces of the retaining ring is larger than an axial air gap formed between the opposing surfaces of the armature and the rotor.   The supporting means for supporting the pair of bearings in a non-movable manner in the axial direction forms engagement grooves at positions facing the inner surface of the inner bearing and the outer surface of the outer bearing on the outer periphery of the rotating shaft, The rotation transmission device according to claim 1 or 2, comprising a structure in which a retaining ring is attached to the engaging groove, and the pair of bearings are pressed against the retaining ring by a spacer installed between the opposing surfaces.   The outer surface of the outer side retaining ring that supports the outer side bearing in a non-movable manner in the axial direction is a tapered surface in which the inner diameter portion of the retaining ring is thinner than the outer diameter portion, and the engaging groove is engaged with the retaining ring. The rotation transmission device according to claim 3, wherein an outer surface of the tapered ring is a tapered surface adapted to a tapered surface of the retaining ring.   The supporting means for supporting the pair of bearings in a non-movable manner in the axial direction includes a large-diameter portion that faces the inner surface of the inner bearing in the axial direction on the outer diameter surface of the rotating shaft, and An engagement groove is formed at a position facing the side surface, a retaining ring is attached to the engagement groove, a spacer is assembled between the pair of bearings, and the inner bearing is pressed against the large diameter portion, and the outer bearing is The rotation transmission device according to claim 1, wherein the rotation transmission device is configured to be pressed against a retaining ring.   The rotation transmission device according to any one of claims 1 to 5, further comprising preload applying means for applying preload to the outer side bearing.   The rotation transmission device according to claim 6, wherein the preload applying means includes an elastic member that presses the inner ring of the outer side bearing toward the inner side bearing.   The rotor positioning means is provided with an inward flange facing the inner surface of the inner bearing in the axial direction on the inner diameter surface of the inner end portion close to the armature of the rotor, and on the inner diameter surface of the outer end portion of the rotor. 2. The structure according to claim 1, wherein an engaging groove is formed at a position facing the outer surface of the outer side bearing, and a pair of bearings are clamped from both sides in the axial direction by a retaining ring attached to the engaging groove and the flange. The rotation transmission device according to any one of Items 7 to 7.   The outer surface of the retaining ring is a tapered surface whose outer diameter portion is thinner than the inner diameter portion, and the outer surface of the engaging groove with which the retaining ring is engaged is adapted to the tapered surface of the retaining ring. The rotation transmission device according to claim 8, which is a surface.

Images