JP6453014B2 - Rotation transmission device and steer-by-wire vehicle steering device - Google Patents

Description

  The present invention relates to a rotation transmission device used for switching rotation transmission and switching.

  As a rotation transmission device used for switching between a state in which rotation is transmitted from an input shaft to an output shaft and a state in which transmission of the rotation is cut off, for example, the one described in Patent Document 1 is known.

  The rotation transmission device described in Patent Document 1 is capable of rotating relative to an input shaft to which rotation is input from the outside, an inner ring connected to the input shaft so as to rotate integrally with the input shaft, and the inner ring. A supported outer ring, and an output shaft connected to the outer ring so as to rotate integrally with the outer ring.

  Between the cylindrical surface provided on the inner periphery of the outer ring and the cam surface provided on the outer periphery of the inner ring, a pair of rollers opposed in the circumferential direction and a roller in a direction to increase the distance between the pair of rollers. An urging roller separating spring is incorporated.

  The rotation transmission device includes: a first roller holder that holds a position of one of the pair of rollers against a biasing force of the roller separating spring; and a position of the other roller of the pair of rollers. A second roller holder that holds the roller separating spring against an urging force; and a cage actuator that relatively moves the first roller holder and the second roller holder.

  The cage actuator is a motion that converts relative movement in the axial direction into relative rotation of the first roller cage and the second roller cage when the first roller cage and the second roller cage are relatively moved in the axial direction. A conversion mechanism, an armature coupled to one of the first roller retainer and the second roller retainer so as to move integrally in the axial direction, a rotor disposed opposite to the armature in the axial direction, and energization And an electromagnet for attracting the armature to the rotor.

  When the energization of the electromagnet of the cage actuator is stopped, the pair of rollers are brought into contact with the cylindrical surface by the biasing force of the roller separation spring that biases each roller in the direction in which the distance between the pair of rollers is increased. Engagement with the cam surface results in a fastening state in which rotation is transmitted between the inner ring and the outer ring.

  On the other hand, when the electromagnet of the retainer actuator is energized, the first roller retainer and the second roller retainer move relative to each other so that each roller moves in the direction in which the distance between the rollers is narrowed. Each roller is disengaged from the cam surface and the rotation of the rotation between the inner ring and the outer ring is cut off.

JP 2012-149746 A

  In the rotation transmission device, when the transmission of rotation between the inner ring and the outer ring is interrupted, each roller is moved in a direction in which the distance between the pair of rollers is narrowed, and each roller is separated from the inner peripheral cylindrical surface of the outer ring. As a result, it becomes idle.

  However, in the rotation transmission device, when vibration is applied to the rotation transmission device in the idling state, the vibration may cause the roller to move to the outer diameter side and come into contact with the inner cylindrical surface of the outer ring. . Further, in the idling state, the roller may move to the outer diameter side by centrifugal force and may come into contact with the inner cylindrical surface of the outer ring. When the roller contacts the cylindrical surface on the inner periphery of the outer ring, there arises a problem that the roller is caught between the cylindrical surface and the cam surface and misengaged.

  The problem to be solved by the present invention is to provide a rotation transmission device in which a roller in the disengagement position is less likely to cause misengagement.

In order to solve the above problems, in the present invention, the following configuration is employed in the rotation transmission device.
An input shaft to which rotation is input from the outside,
An inner ring connected to the input shaft so as to rotate integrally with the input shaft;
An outer ring supported to be rotatable relative to the inner ring;
An output shaft connected to the outer ring so as to rotate integrally with the outer ring;
A cylindrical surface provided on the inner periphery of the outer ring;
A cam surface provided on the outer periphery of the inner ring so as to form a wedge space gradually narrowing from the circumferential center to both ends in the circumferential direction between the cylindrical surface,
A pair of rollers assembled in a circumferential direction between the cylindrical surface and the cam surface;
A roller separation spring that urges the roller in a direction to increase the distance between the pair of rollers;
A spring holding portion disposed between the pair of rollers and holding the roller separating spring;
A first roller holder that holds the position of one of the pair of rollers against the biasing force of the roller separating spring;
A second roller holder that holds the position of the other roller of the pair of rollers against the urging force of the roller separating spring;
An engagement position where the pair of rollers engages between the cylindrical surface and the cam surface, and an engagement release position where the pair of rollers releases engagement between the cylindrical surface and the cam surface. A rotation transmission device having a retainer actuator for relatively moving the first roller retainer and the second roller retainer so that the pair of rollers move between them;
The spring holding portion is not in contact with each roller when the pair of rollers are in the engagement position, and is in contact with each roller when the pair of rollers is in the disengagement position. And a roller stopper portion for restricting the movement of each roller to the outer diameter side.

  In this way, when each roller is moved in the direction in which the distance between the pair of rollers is reduced and the engagement of each roller between the cylindrical surface and the cam surface is released, each roller is It comes into contact with the roller stopper provided in the spring holding portion between them, and the movement to the outer diameter side is restricted. Therefore, even if vibration or centrifugal force acts on the roller in a state where the roller is in the disengagement position, the roller does not move to the outer diameter side, and misengagement of the roller can be prevented.

  The roller stopper portion is preferably provided so as to contact each roller on the outer diameter side with respect to a reference circle connecting the centers of the pair of rollers with the inner ring as a center.

  In this case, the roller stopper portion comes into contact with the roller on the outer diameter side from the radial position where the width of the roller is maximum (that is, the position on the reference circle connecting the centers of the pair of rollers with the inner ring as the center). Therefore, it is possible to effectively prevent the roller from moving to the outer diameter side.

  Further, it is preferable that the roller stopper portion is formed in a concave arc shape in cross section along the outer periphery of the roller at a contact portion with each of the rollers.

  In this way, when the roller contacts the roller stopper portion, the roller stopper portion having a concave arc shape in section and a part of the outer periphery of the roller are fitted, so the position of the roller in contact with the roller stopper portion Becomes stable, and the radial movement of the roller due to vibration or centrifugal force can be effectively prevented.

  As the first roller holder and the second roller holder, one having a first pillar portion and a second pillar portion facing each other in the circumferential direction with the pair of rollers interposed therebetween can be adopted. At this time, it is preferable that the first pillar part and the second pillar part are formed so as to have a contact portion with each roller on the outer diameter side of a reference circle connecting the centers of the pair of rollers with the inner ring as a center. .

  In this case, the first pillar part and the second pillar part have an outer diameter that is greater than the radial position where the width of the roller is maximum (that is, the position on the reference circle connecting the centers of the pair of rollers with the inner ring as the center). Since it contacts the roller on the side, it is possible to effectively prevent the roller from moving to the outer diameter side.

  It is preferable that the first column portion and the second column portion are formed in a concave arc shape in cross section along the outer periphery of the roller at a contact portion with each roller.

  By doing so, the concave circular arc sections of the first pillar part and the second pillar part are fitted to a part of the outer periphery of the roller, so that the position of the roller becomes stable, and the roller caused by vibration or centrifugal force It is possible to effectively prevent the movement in the radial direction.

As the cage actuator,
A motion conversion mechanism for converting the relative movement in the axial direction into relative rotation of the first roller holder and the second roller holder when the first roller holder and the second roller holder are relatively moved in the axial direction; ,
An armature connected to one of the first roller holder and the second roller holder so as to move integrally in the axial direction;
A rotor disposed axially opposite the armature;
It is possible to employ an electromagnet that attracts the armature to the rotor by energization.

Moreover, in this invention, the thing of the following structures is provided as a vehicle steering device using said rotation transmission device.
A steering wheel,
A steering actuator that moves the pair of wheels so that the directions of the pair of left and right wheels change according to the steering angle of the steering wheel;
A steer-by-wire system having the rotation transmission device that interrupts transmission of rotation between the steering wheel and the steering actuator when normal, and transmits rotation between the steering wheel and the steering actuator when abnormal. Vehicle steering system.

  In the rotation transmission device according to the present invention, when each roller is moved in the direction in which the distance between the pair of rollers is narrowed and the engagement of each roller between the cylindrical surface and the cam surface is released, It comes into contact with the roller stopper provided in the spring holding part between the rollers, and the movement to the outer diameter side is restricted. Therefore, even if vibration or centrifugal force acts on the roller in a state where the roller is in the disengagement position, the roller does not move to the outer diameter side, and misengagement of the roller can be prevented.

Sectional drawing which shows the rotation transmission apparatus concerning embodiment of this invention The enlarged view of the vicinity of the 1st roller holder and the 2nd roller holder of Drawing 1 Sectional view along line III-III in FIG. Sectional drawing which expands and shows the vicinity of a pair of roller of FIG. Sectional view along line V-V in FIG. Sectional view along line VI-VI in FIG. Sectional view along line VII-VII in FIG. 7A is a cross-sectional view taken along line VIII-VIII in FIG. 7, and FIG. 7B is a diagram in which the first roller holder and the second roller holder are rotated relative to each other when the ball shown in FIG. 7A rolls along the cam groove. Sectional view showing the condition The figure which expands and shows the vicinity of the spring holding part of FIG. The figure which shows the modification of the spring holding | maintenance part shown in FIG. The figure which shows the modification of the 1st pillar part shown in FIG. 9, and a 2nd pillar part The figure which expands and shows the vicinity of the 1st pillar part of FIG. Schematic showing an example of a steer-by-wire vehicle steering device using the rotation transmission device shown in FIG.

  FIG. 1 shows a rotation transmission device 1 according to an embodiment of the present invention. The rotation transmission device 1 includes an outer ring 2, an inner ring 3 disposed on the inner side of the outer ring 2, a plurality of rollers 4a and 4b incorporated between the inner periphery of the outer ring 2 and the outer periphery of the inner ring 3, and these A first roller holder 5a and a second roller holder 5b that hold the rollers 4a and 4b, respectively, and a holder actuator 6 that relatively moves the first roller holder 5a and the second roller holder 5b. An input shaft 7 is connected to the inner ring 3, and an output shaft 8 is connected to the outer ring 2. The input shaft 7 and the output shaft 8 are arranged on the same axis.

  The input shaft 7 is an axis to which rotation is input from the outside. The input shaft 7 and the inner ring 3 are formed as an integral member without a joint so that both rotate together. The input shaft 7 and the inner ring 3 may be formed as separate members and connected by serration fitting or the like.

  The output shaft 8 and the outer ring 2 are also formed as a seamless integral member so that both rotate integrally. The output shaft 8 and the outer ring 2 may be formed as separate members, and both may be connected by serration fitting or the like. A rolling bearing 9 is incorporated between the outer ring 2 and the inner ring 3 to support the outer ring 2 so as to be rotatable relative to the inner ring 3. A rolling bearing 11 that rotatably supports the output shaft 8 is incorporated in an end portion on the output shaft 8 side of the cylindrical housing 10 that houses the constituent members of the rotation transmission device 1.

  As shown in FIGS. 2 and 3, a plurality of cam surfaces 12 are provided on the outer periphery of the inner ring 3 at intervals in the circumferential direction. Each cam surface 12 includes a front cam surface 12a and a rear cam surface 12b disposed rearward in the forward rotation direction of the inner ring 3 with respect to the front cam surface 12a. A cylindrical surface 13 that is opposed to the cam surface 12 in the radial direction is provided on the inner periphery of the outer ring 2.

  As shown in FIG. 4, between the cam surface 12 and the cylindrical surface 13, a pair of rollers 4a and 4b that are opposed to each other in the circumferential direction with a roller separation spring 14 interposed therebetween are incorporated. Of the pair of rollers 4a and 4b, the front roller 4a in the forward rotation direction is incorporated between the front cam surface 12a and the cylindrical surface 13, and the rear roller 4b in the forward rotation direction is the rear cam surface 12b and the cylindrical surface 13. Is built in between. Each roller 4a, 4b is urged by a roller separation spring 14 in a direction in which the distance between the pair of rollers 4a, 4b increases.

  Between the cam surface 12 and the cylindrical surface 13, a wedge space that is gradually narrowed from the center in the circumferential direction toward both ends in the circumferential direction is formed. That is, the front cam surface 12a is formed such that the radial distance from the cylindrical surface 13 gradually decreases from the position of the roller 4a toward the front in the forward rotation direction. The rear cam surface 12b is formed such that the radial distance from the cylindrical surface 13 gradually decreases from the position of the roller 4b toward the rear in the forward rotation direction. In the figure, the front cam surface 12a and the rear cam surface 12b are formed so as to be separate planes inclined in opposite directions, but the front cam surface 12a and the rear cam surface 12b are forwardly rotated in a single plane. It is also possible to form on the same plane so that the front portion in the direction becomes the front cam surface 12a and the rear portion becomes the rear cam surface 12b. Further, the front cam surface 12a and the rear cam surface 12b can be curved surfaces. However, if the front cam surface 12a and the rear cam surface 12b are flat as shown in the figure, the processing cost can be reduced.

  As shown in FIG. 3, each roller 4a, 4b is engaged between the cylindrical surface 13 and the cam surface 12, and between the cylindrical surface 13 and the cam surface 12, as shown in FIG. It is possible to move in the circumferential direction between an engagement release position for releasing the engagement.

  The first roller holder 5a holds the position of one roller 4a of the pair of rollers 4a, 4b opposed in the circumferential direction with the roller separation spring 14 therebetween, against the biasing force of the roller separation spring 14, The second roller holder 5b holds the position of the other roller 4b out of the pair of rollers 4a, 4b opposed in the circumferential direction with the roller separation spring 14 therebetween, against the urging force of the roller separation spring 14. Yes.

  As shown in FIGS. 2 and 3, the first roller holder 5 a connects a plurality of first pillar portions 15 a arranged at intervals in the circumferential direction and the end portions of these first pillar portions 15 a. And an annular first flange portion 16a. Similarly, the second roller holder 5b also includes a plurality of second column portions 15b arranged at intervals in the circumferential direction, and an annular second flange portion that connects the ends of the second column portions 15b. 16b.

  As shown in FIG. 4, the first pillar portion 15a and the second pillar portion 15b are opposed to each other in the circumferential direction with the pair of rollers 4a and 4b interposed therebetween. That is, the first pillar portion 15a and the second pillar portion 15b are arranged so that the pair of rollers 4a and 4b opposed in the circumferential direction with the roller separation spring 14 therebetween are sandwiched from both sides in the circumferential direction. It is inserted between the outer circumferences of the inner ring 3.

  As shown in FIG. 2, the first flange portion 16a and the second flange portion 16b are arranged to face each other in the axial direction so that the second flange portion 16b is closer to the inner ring 3 than the first flange portion 16a. Has been. The second flange portion 16b is provided with a plurality of notches 17 at intervals in the circumferential direction to avoid interference with the first column portion 15a of the first roller holder 5a (see FIG. 7). .

  The inner periphery of the first flange portion 16a and the inner periphery of the second flange portion 16b are rotatably supported by a cylindrical surface 18 provided on the outer periphery of the input shaft 7. The first flange portion 16a is supported in the axial direction by an annular support member 20 fixed to the outer periphery of the input shaft 7 via the thrust bearing 19, and thereby movement in the axial direction is restricted. A spring holder 21 is fixed to the side surface of the inner ring 3.

  As shown in FIGS. 5 and 6, the spring holder 21 has a plurality of spring holding portions 22 that hold the roller separation spring 14 at intervals in the circumferential direction. Each spring holding portion 22 is disposed between a pair of rollers 4a and 4b that face each other in the circumferential direction with the roller separation spring 14 therebetween. The spring holding portion 22 is attached to the inner ring 3 so that the relative position with respect to the inner ring 3 does not change.

  As shown in FIGS. 4 and 6, the spring holding portion 22 is opposed to the spring support surface 23 formed between the front cam surface 12 a and the rear cam surface 12 b on the outer periphery of the inner ring 3 in the radial direction. Is formed. A recess 24 for accommodating the roller separation spring 14 is formed on the surface of the spring holding portion 22 that faces the spring support surface 23. The roller separation spring 14 is a compression coil spring. The spring holding portion 22 restricts the movement of the roller separation spring 14 by the recess 24, thereby preventing the roller separation spring 14 from dropping in the axial direction from between the inner periphery of the outer ring 2 and the outer periphery of the inner ring 3. ing. If the spring holding part 22 is provided in the spring holder 21 separate from the inner ring 3 as in this embodiment, the processing of the spring holding part 22 is easy and the cost is low. It is also possible to integrally form the outer periphery.

  As shown in FIG. 4, the circumferential width dimension of the spring holding portion 22 increases from the position on the reference circle D connecting the centers of the pair of rollers 4 a and 4 b centering on the inner ring 3 toward the outer diameter side. It is made into a shape. The spring holding portion 22 has roller stopper portions 25 at both ends in the circumferential direction for receiving the rollers 4a and 4b when the rollers 4a and 4b move in a direction in which the distance between the pair of rollers 4a and 4b decreases. As shown in FIG. 3, the roller stopper 25 is in non-contact with each of the rollers 4a and 4b when the pair of rollers 4a and 4b are in the engaged position, and as shown in FIG. 4, the pair of rollers 4a and 4b. Is in the disengagement position, it is formed so as to restrict the movement of the rollers 4a and 4b to the outer diameter side by contacting the rollers 4a and 4b. As such a roller stopper portion 25, a circumferential protruding portion formed on the outer diameter side of a portion of the spring holding portion 22 located on the reference circle D can be employed. In this way, since the roller stopper portion 25 contacts the rollers 4a and 4b on the outer diameter side of the reference circle D, the movement of the rollers 4a and 4b to the outer diameter side can be effectively restricted. . Further, as shown in FIG. 9, the roller stopper portion 25 is formed in a concave arc shape in cross section along the outer periphery of the rollers 4a and 4b at the contact portion with the pair of rollers 4a and 4b. The roller stopper 25 can also be formed in a rectangular cross section as shown in FIG.

  As shown in FIG. 1, when the first roller holder 5a and the second roller holder 5b move relative to each other in the axial direction, the cage actuator 6 changes the relative movement in the axial direction between the first roller holder 5a and the first roller holder 5a. A motion conversion mechanism 26 for converting the relative rotation of the two-roller cage 5b, an armature 27 connected to the second roller cage 5b, a rotor 28 disposed axially opposite the armature 27, and an armature by energization. And an electromagnet 29 that attracts the rotor 27 to the rotor 28.

  As shown in FIG. 2, the armature 27 includes an annular disk part 30 and a cylindrical part 31 that is integrally formed so as to extend in the axial direction from the outer periphery of the disk part 30. The cylindrical portion 31 of the armature 27 is fitted to the outer periphery of the outer connecting ring of the second roller holder 5b with a tightening margin. By this fitting, the armature 27 is integrated with the second roller holder 5b in the axial direction. It is connected to the second roller holder 5b so as to move. The armature 27 is supported on the outer periphery of the input shaft 7 so as to be rotatable and movable in the axial direction. Here, the armature 27 is supported at two positions separated in the axial direction (that is, the inner circumference of the armature 27 and the inner circumference of the second roller holder 5b), so that the posture of the armature 27 is in the direction perpendicular to the axis. Tilt is prevented.

  The rotor 28 is disposed between the armature 27 and the electromagnet 29. In addition, the rotor 28 is supported on the outer periphery of the input shaft 7 so as not to move relative to either the axial direction or the circumferential direction by fitting to the outer periphery of the input shaft 7 with a tightening margin. The rotor 28 and the armature 27 are made of a ferromagnetic metal.

  As shown in FIG. 1, the electromagnet 29 has a field core 32 and a solenoid coil 33 wound around the field core 32. The field core 32 is inserted into the end of the housing 10 on the input shaft 7 side, and is prevented from coming off by a retaining ring 34. A rolling bearing 35 that rotatably supports the input shaft 7 is attached to the field core 32. The electromagnet 29 energizes the solenoid coil 33 to form a magnetic path that passes through the field core 32, the rotor 28, and the armature 27, and attracts the armature 27 to the rotor 28.

  As shown in FIGS. 7 and 8 (a) and 8 (b), the motion conversion mechanism 26 includes a first cam groove 36a provided on a surface of the first flange portion 16a facing the second flange portion 16b, and a second cam groove 36a. The flange portion 16b includes a second cam groove 36b provided on a surface facing the first flange portion 16a, and a ball 37 incorporated between the first cam groove 36a and the second cam groove 36b. The first cam groove 36a and the second cam groove 36b are formed so as to extend in the circumferential direction, respectively. The first cam groove 36 a has a shape with a groove bottom inclined so as to gradually become deeper in the circumferential direction from the contact position with the ball 37, and the second cam groove 36 b is also connected to the ball 37. The shape has a groove bottom inclined so as to gradually become deeper in the circumferential direction from the contact position. The ball 37 is disposed so as to be sandwiched between the groove bottom of the first cam groove 36a and the groove bottom of the second cam groove 36b.

  When the second flange portion 16b moves in the axial direction toward the first flange portion 16a, the motion conversion mechanism 26 is configured so that the ball 37 rolls along the cam grooves 36a and 36b, thereby 5a and the second roller retainer 5b rotate relative to each other, and as a result, the first column portion 15a and the second column portion 15b operate so as to move in a direction of narrowing the distance between the pair of rollers 4a and 4b.

  An operation example of the rotation transmission device 1 will be described.

  As shown in FIG. 1, when energization to the electromagnet 29 is stopped, the rotation transmission device 1 is in a fastening state in which rotation is transmitted between the outer ring 2 and the inner ring 3. In other words, the armature 27 is separated from the rotor 28 by the force of the roller separation spring 14 when energization to the electromagnet 29 is stopped. Further, at this time, the roller 4a on the front side in the forward rotation direction causes the inner ring of the outer ring 2 to be moved by the force of the roller separation spring 14 that presses the rollers 4a and 4b in the direction in which the distance between the pair of rollers 4a and 4b increases. The roller 4b on the rear side in the forward rotation direction waits for engagement between the cylindrical surface 13 and the front cam surface 12a on the outer periphery of the inner ring 3, and the outer peripheral surface of the inner ring 3 and the inner ring 3 It is in a state of waiting for engagement with the rear cam surface 12b. In this state, when the inner ring 3 rotates in the forward direction, the rear roller 4b in the forward direction is engaged between the cylindrical surface 13 and the rear cam surface 12b, and the inner ring 3 and the outer ring 2 are engaged via the roller 4b. Rotation is transmitted to When the inner ring 3 rotates in the reverse direction, the forward roller 4a in the forward direction engages between the cylindrical surface 13 and the front cam surface 12a, and the rotation is transmitted from the inner ring 3 to the outer ring 2 via the roller 4a. To do.

  On the other hand, when the electromagnet 29 is energized, the rotation transmission device 1 is in an idling state where transmission of rotation between the outer ring 2 and the inner ring 3 is blocked. That is, when the electromagnet 29 is energized, the armature 27 is attracted to the rotor 28, and the second flange portion 16b moves in the axial direction toward the first flange portion 16a in conjunction with the operation of the armature 27. At this time, the ball 37 of the motion conversion mechanism 26 rolls along the cam grooves 36a and 36b, whereby the first roller holder 5a and the second roller holder 5b rotate relative to each other. Then, due to the relative rotation of the first roller holder 5a and the second roller holder 5b, as shown in FIG. 4, the first column portion 15a and the second column portion 15b have a distance between the pair of rollers 4a and 4b. As a result, the rollers 4a and 4b are pressed in the narrowing direction, and as a result, there is a small gap between the front roller 4a in the forward rotation direction and the cylindrical surface 13 in the engagement standby state of the front roller 4a in the forward rotation direction. When the inner ring 3 rotates in the reverse direction, the roller 4a immediately engages between the cylindrical surface 13 and the front cam surface 12a) and the waiting state for engaging the rear roller 4b in the forward direction ( There is a minute gap between the roller 4b on the rear side in the forward rotation direction and the cylindrical surface 13, but when the inner ring 3 rotates in the forward rotation direction, the roller 4b immediately engages between the cylindrical surface 13 and the rear cam surface 12b. ) Is also released. In this state, even if rotation is input to the inner ring 3, the rotation is not transmitted from the inner ring 3 to the outer ring 2, and the inner ring 3 rotates idle.

  By the way, in the idling state shown in FIG. 4, when vibration is applied to the rotation transmission device 1, the vibration causes the rollers 4 a and 4 b to move to the outer diameter side to come into contact with the cylindrical surface 13 on the inner periphery of the outer ring 2. There is a possibility that the rollers 4a and 4b move to the outer diameter side due to the centrifugal force acting on the 4a and 4b and come into contact with the inner cylindrical surface 13 of the outer ring 2. When the rollers 4a and 4b come into contact with the cylindrical surface 13 on the inner periphery of the outer ring 2, there arises a problem that the rollers 4a and 4b are caught between the cylindrical surface 13 and the cam surface 12 and misengaged.

  In response to such a problem, in the rotation transmission device 1, roller stopper portions 25 that restrict the movement of the rollers 4 a and 4 b to the outer diameter side are provided at both circumferential ends of the spring holder 21. Thereby, when the engagement of the rollers 4a and 4b between the cylindrical surface 13 and the cam surface 12 is released, the rollers 4a and 4b come into contact with the roller stopper portion 25, and the movement toward the outer diameter side is prevented. It becomes a regulated state. Therefore, even if vibration or centrifugal force acts on the rollers 4a and 4b with the rollers 4a and 4b in the disengagement position, the rollers 4a and 4b do not move to the outer diameter side, and the rollers 4a and 4b are misengaged. Can be prevented.

  Further, in this rotation transmission device 1, the roller stopper 25 comes into contact with the rollers 4a and 4b on the outer diameter side with respect to the radial position (that is, the position on the reference circle D) where the width of the rollers 4a and 4b is maximum. Therefore, it is possible to effectively prevent the rollers 4a and 4b from moving to the outer diameter side.

  Further, in the rotation transmission device 1, when the rollers 4a and 4b contact the roller stopper portion 25, the roller stopper portion 25 having a concave arcuate cross section and a part of the outer periphery of the rollers 4a and 4b are fitted. The positions of the rollers 4a and 4b in contact with the roller stopper 25 are stabilized, and it is possible to effectively prevent the rollers 4a and 4b from moving in the radial direction due to vibration or centrifugal force.

  As shown in FIG. 4, it is preferable to form the first pillar portion 15a and the second pillar portion 15b so as to have contact portions with the rollers 4a and 4b on the outer diameter side of the reference circle D. If it does in this way, the 1st pillar part 15a and the 2nd pillar part 15b will be roller 4a, 4b on the outer diameter side rather than the radial direction position (namely, position on the reference | standard circle D) where the width | variety of roller 4a, 4b becomes the maximum. Therefore, it is possible to effectively prevent the rollers 4a and 4b from moving to the outer diameter side.

  As shown in FIG. 11 and FIG. 12, the first pillar portion 15a and the second pillar portion 15b form the contact portions 48 with the respective rollers 4a and 4b in a concave arc shape along the outer circumference of the rollers 4a and 4b. Can do. In this way, the portion 48 having a concave arc shape in cross section of the first pillar portion 15a and the second pillar portion 15b and a part of the outer periphery of the rollers 4a and 4b are fitted, so that the positions of the rollers 4a and 4b are stabilized. Thus, the radial movement of the rollers 4a and 4b due to vibration and centrifugal force can be effectively prevented.

  The above-described rotation transmission device 1 is used, for example, in a vehicle steering device shown in FIG. This vehicle steering device is a steer-by-wire vehicle steering device that converts the steering angle of the steering wheel 40 by the driver into an electrical signal and steers the left and right wheels 41 based on the electrical signal.

  The vehicle steering apparatus includes a steering wheel 40, a steering actuator 42 that moves the pair of wheels 41 so that the directions of the pair of left and right wheels 41 change according to the steering angle of the steering wheel 40, and the steering wheel 40. And the rotation transmission device 1 incorporated in the middle of the rotation transmission path between the rudder actuators 42. The rotation transmission device 1 interrupts transmission of rotation between the steering wheel 40 and the steering actuator 42 when normal, and transmits rotation between the steering wheel 40 and the steering actuator 42 when abnormal such as when power is lost. Functions as a backup clutch. A reaction force actuator 43 that applies a steering reaction force to the steering wheel 40 according to the behavior of the vehicle is connected to the steering wheel 40.

  In the rotation transmission device 1, the input shaft 7 is connected to the shaft 45 on the steering wheel 40 side via the shaft joint 44, and the output shaft 8 is connected to the shaft 47 on the steering actuator 42 side via the shaft joint 46. ing.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Rotation transmission apparatus 2 Outer ring 3 Inner ring 4a, 4b Roller 5a First roller holder 5b Second roller holder 6 Cage actuator 7 Input shaft 8 Output shaft 12 Cam surface 13 Cylindrical surface 14 Roller separation spring 15a First column portion 15b Second pillar portion 22 Spring holding portion 25 Roller stopper portion 26 Motion conversion mechanism 27 Armature 28 Rotor 29 Electromagnet 40 Steering wheel 41 Wheel 42 Steering actuator D Reference circle

Claims (7)

An input shaft (7) to which rotation is input from the outside;
An inner ring (3) connected to the input shaft (7) so as to rotate integrally with the input shaft (7);
An outer ring (2) supported so as to be rotatable relative to the inner ring (3);
An output shaft (8) connected to the outer ring (2) so as to rotate integrally with the outer ring (2);
A cylindrical surface (13) provided on the inner periphery of the outer ring (2);
A cam surface (12) provided on the outer periphery of the inner ring (3) so as to form a wedge space gradually narrowing from the circumferential center to both ends in the circumferential direction between the cylindrical surface (13) and
A pair of rollers (4a, 4b) incorporated in the circumferential direction between the cylindrical surface (13) and the cam surface (12);
A roller separation spring (14) for urging the rollers (4a, 4b) in a direction to increase the distance between the pair of rollers (4a, 4b);
A spring holding part (22) disposed between the pair of rollers (4a, 4b) and holding the roller separating spring (14);
A first roller holder (5a) for holding the position of one roller (4a) of the pair of rollers (4a, 4b) against the urging force of the roller separating spring (14);
A second roller holder (5b) that holds the position of the other roller (4b) of the pair of rollers (4a, 4b) against the urging force of the roller separating spring (14);
An engagement position where the pair of rollers (4a, 4b) engage between the cylindrical surface (13) and the cam surface (12), and the pair of rollers (4a, 4b) include the cylindrical surface (13). And the first roller retainer (5a) and the second roller so that the pair of rollers (4a, 4b) move between the engagement position and the disengagement position for releasing the engagement between the cam surface (12). In the rotation transmission device having the cage actuator (6) for relatively moving the roller cage (5b),
The spring holding portion (22) is fixed to the inner ring (3) so that its relative position cannot be changed, and the spring holding portion (22) is in the state where the pair of rollers (4a, 4b) are in the engagement position. The rollers (4a, 4b) are not in contact with each other, and the spring holding portion (22) is in contact with the rollers (4a, 4b) when the pair of rollers (4a, 4b) are in the disengaged position. A rotation transmission device comprising a roller stopper portion (25) for restricting movement of each roller (4a, 4b) to the outer diameter side by contact.   The roller stopper portion (25) includes a roller (4a, 4b) on the outer diameter side of a reference circle (D) that connects the centers of the pair of rollers (4a, 4b) with the inner ring (3) as a center. The rotation transmission device according to claim 1, wherein the rotation transmission device is provided in contact with the rotation transmission device.   The rotation according to claim 1 or 2, wherein the roller stopper portion (25) is formed in a concave arc shape in cross section along the outer periphery of the roller (4a, 4b) at a contact portion with the rollers (4a, 4b). Transmission device. The first roller holder (5a) and the second roller holder (5b) include a first column portion (15a) and a second column that are opposed to each other in the circumferential direction with the pair of rollers (4a, 4b) interposed therebetween. Part (15b),
The first pillar portion (15a) and the second pillar portion (15b) are on the outer diameter side from a reference circle (D) connecting the centers of the pair of rollers (4a, 4b) with the inner ring (3) as a center. The rotation transmission device according to any one of claims 1 to 3, wherein the rotation transmission device is formed so as to have a contact portion with each roller (4a, 4b).   In the first pillar portion (15a) and the second pillar portion (15b), a contact portion (48) with each of the rollers (4a, 4b) is formed in a concave circular arc shape along the outer periphery of the roller (4a, 4b). The rotation transmission device according to claim 4. The cage actuator (6)
When the first roller holder (5a) and the second roller holder (5b) move relative to each other in the axial direction, the relative movement in the axial direction is changed to the first roller holder (5a) and the second roller holder ( A motion conversion mechanism (26) that converts the relative rotation of 5b);
An armature (27) connected to one of the first roller holder (5a) and the second roller holder (5b) so as to move integrally in the axial direction;
A rotor (28) disposed axially opposite the armature (27);
The rotation transmission device according to any one of claims 1 to 5, comprising an electromagnet (29) for attracting the armature (27) to the rotor (28) by energization. A steering wheel (40);
A steering actuator (42) for moving the pair of wheels (41) so that the directions of the pair of left and right wheels (41) change according to the steering angle of the steering wheel (40);
When normal, the transmission of rotation between the steering wheel (40) and the steering actuator (42) is cut off, and when abnormal, the rotation is transmitted between the steering wheel (40) and the steering actuator (42). In a steer-by-wire vehicle steering apparatus having a rotation transmission device (1) that
A steer-by-wire vehicle steering device using the rotation transmission device according to any one of claims 1 to 6 as the rotation transmission device (1).

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