JP6501475B2 - Rotational transmission device and steer-by-wire vehicle steering device - Google Patents

Description

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

  As a rotation transmission device used to switch 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 shut off, for example, the one described in Patent Document 1 is known.

  The rotation transmission device described in Patent Document 1 is capable of relative rotation with respect 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 facing in the circumferential direction and the rollers in a direction to widen the distance between the pair of rollers A biasing roller separating spring is incorporated. Here, in the cam surface, a portion in contact with the roller when the roller is in the engagement position and a portion in contact with the roller when the roller is in the engagement release position are formed on the same plane.

  The rotation transmission device further includes a first roller holder that holds the position of one of the pair of rollers against the biasing force of the roller separation spring, and the position of the other of the pair of rollers. It has a second roller holder which holds against the biasing force of the roller separating spring, and a holder actuator which moves the first roller holder and the second roller holder relative to each other.

  The holder actuator is a motion that converts the relative movement in the axial direction into the relative rotation of the first roller holder and the second roller holder when the first roller holder and the second roller holder move in the axial direction relative to each other. A conversion mechanism, an armature connected so as to move integrally with one of the first roller holder and the second roller holder in the axial direction, a rotor disposed axially opposite to the armature, and electricity. And an electromagnet for attracting the armature to the rotor.

  Then, when energization of the electromagnet of the holder actuator is stopped, the biasing force of the roller separating spring that biases each roller in the direction in which the distance between the pair of rollers increases causes the pair of rollers to have a cylindrical surface It engages with the cam surface, and is in the engaged state in which the rotation is transmitted between the inner ring and the outer ring.

  On the other hand, when the electromagnet of the cage actuator is energized, the first roller cage and the second roller cage move relative to each other, so that each roller moves in the direction in which the distance between the rollers is narrowed, and the cylindrical surface The engagement of each roller between the cam and the cam surface is released, resulting in an idle state in which the transmission of rotation between the inner ring and the outer ring is blocked.

JP 2012-149746 A

  In the above rotation transmission device, when blocking transmission of rotation between the inner ring and the outer ring, each roller is moved in a direction in which the distance between the pair of rollers narrows, and each roller separates from the cylindrical surface of the inner periphery of the outer ring It becomes idle.

  In the above-described rotation transmission device, when vibration is applied to the rotation transmission device in an idle state, the vibration may move the roller to the outer diameter side and contact the cylindrical surface of the inner periphery of the outer ring. In addition, in the idle state, the roller may move to the outer diameter side by centrifugal force and may come in contact with the cylindrical surface of the inner periphery of the outer ring. When the roller comes in contact with the cylindrical surface of the inner periphery of the outer ring, the roller bites between the cylindrical surface and the cam surface, causing a problem of mis-engagement.

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

In order to solve the above-mentioned subject, in the present invention, the following composition was adopted as a rotation transmission device.
An input axis 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 rotatably supported 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 which is gradually narrowed from the circumferential center to both circumferential directions from the circumferential surface with the cylindrical surface;
A pair of rollers circumferentially opposed and incorporated between the cylindrical surface and the cam surface;
A roller separating spring that biases the rollers in a direction to widen the distance between the pair of rollers;
A first roller holder that holds the position of one of the pair of rollers against the biasing force of the roller separation spring;
A second roller holder that holds the position of the other roller of the pair of rollers against the biasing force of the roller separation spring;
An engagement position in which the pair of rollers engage between the cylindrical surface and the cam surface, and an engagement release position in which the pair of rollers cancel the engagement between the cylindrical surface and the cam surface And a holder actuator for relatively moving the first roller holder and the second roller holder so that the pair of rollers move between the rollers.
The roller is in the engagement position at an angle formed by a portion of the cam surface in contact with the roller when the roller is in the engagement release position with respect to the direction of the reference line connecting the centers of the pair A rotation transmission device characterized in that it is formed to be smaller than an angle formed by a portion in contact with a roller in a state.

  With this configuration, the cams are arranged such that the portion of the cam surface in contact with the roller when the roller is in the engaged position and the portion of the cam surface that is in contact with the roller when the roller is in the disengaged position lie on the same plane. The roller with the roller in the disengagement position while maintaining the angle of the portion of the cam surface contacting the roller with the roller in the engaged position, as compared to when the surface is formed, in an appropriate size It is possible to set a large gap from the above to the cylindrical surface of the inner periphery of the outer ring. Therefore, even if vibration or centrifugal force acts on the roller in a state where the roller is in the engagement release position, the roller is less likely to contact the cylindrical surface of the inner periphery of the outer ring, and mis-engagement of the roller can be prevented.

  The cam surface may have a flat surface in which a portion in contact with the roller when the roller is in the engagement position and a portion in contact with the roller when the roller is in the engagement release position. it can.

  In this way, the portion of the cam surface in contact with the roller when the roller is in the engaged position and the portion of the cam surface that is in contact with the roller when the roller is in the engagement release position can be machined with high accuracy.

  In the cam surface, a portion in contact with one of the rollers and a portion in contact with the other roller in a state in which the pair of rollers is in the disengagement position are both flat, and the two planes are on the same plane Can be adopted.

  With this configuration, it is possible to more effectively set the gap from the roller to the cylindrical surface of the inner periphery of the outer ring when the roller is in the engagement release position.

  The cam surface has a flat surface at a portion in contact with the roller when the roller is in the engaged position, and an outer diameter side where a portion in contact with the roller is smoothly connected to the surface when the roller is in the disengaged position A convex arc surface may be adopted toward.

  In this way, the processing accuracy of the portion in contact with the roller in the engaged position can be ensured, and the movement of the roller between the engaged position and the disengaged position can be made smooth. It becomes possible.

As the cage actuator,
A motion conversion mechanism that converts 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 move relative to each other in the axial direction; ,
An armature connected so as to move axially integrally with one of the first roller holder and the second roller holder;
A rotor axially opposed to the armature;
It is possible to employ one comprising an electromagnet for attracting the armature to the rotor by energization.

Moreover, in this invention, the thing of the following structures is provided as a steering apparatus for vehicles using said rotation transmission apparatus.
With the steering wheel,
A steering actuator that moves the pair of wheels such that the direction of the pair of left and right wheels changes in accordance with the steering angle of the steering wheel;
A steer-by-wire system comprising: the rotation transmission device for interrupting the transmission of rotation between the steering wheel and the steering actuator when normal; and transmitting the rotation between the steering wheel and the steering actuator when abnormal. Vehicle steering system.

  In the rotation transmission device of the present invention, the portion of the cam surface contacting the roller when the roller is in the engaged position and the portion of the cam surface contacting the roller when the roller is in the disengaging position are coplanar. The roller is in the disengagement position while maintaining the angle of the portion of the cam surface in contact with the roller in an appropriate size with the roller in the engagement position as compared to the case where the cam surface is formed It is possible to set a large gap from the roller in the above to the cylindrical surface of the inner periphery of the outer ring. Therefore, even if vibration or centrifugal force acts on the roller in a state where the roller is in the engagement release position, the roller is less likely to contact the cylindrical surface of the inner periphery of the outer ring, and mis-engagement of the roller can be prevented.

Sectional drawing which shows the rotation transmission apparatus concerning embodiment of this invention An enlarged view of the vicinity of the first roller holder and the second roller holder of FIG. 1 Sectional view along line III-III in FIG. 1 Sectional drawing which expands and shows the vicinity of a pair of roller of FIG. 3 Sectional view along the line V-V in FIG. 1 Sectional view along line VI-VI in FIG. 5 Sectional view along line VII-VII in FIG. 1 (A) is a cross-sectional view taken along the line VIII-VIII in FIG. 7, (b) is a relative rotation of the first roller holder and the second roller holder when the ball shown in (a) rolls along the cam groove Section showing the broken state The figure which shows the state which the roller shown in FIG. 4 moved to the engagement release position from an engagement position. The figure which shows the state in which a pair of roller of the conventional rotation transmission apparatus exists in an engagement release position. It is a figure which shows the modification of the cam surface shown in FIG. 4, and is a figure which shows the state which a pair of roller exists in an engagement position. The figure which shows the state which the roller shown in FIG. 11 moved to the engagement release position from an engagement position. The figure which shows the other modification of the cam surface shown in FIG. A schematic view showing an example of a steer-by-wire vehicle steering apparatus using the rotation transmission device shown in FIG. 1

  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 inside the outer ring 2, and 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 A first roller holder 5a and a second roller holder 5b for holding the rollers 4a and 4b, respectively, and a holder actuator 6 for relatively moving 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 coaxially arranged.

  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 a seamless integral member so that both rotate integrally. The input shaft 7 and the inner ring 3 may be formed as separate members, and both may be 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 for supporting the outer ring 2 rotatably relative to the inner ring 3. A rolling bearing 11 for rotatably supporting the output shaft 8 is incorporated at an end of the cylindrical housing 10 housing the component of the rotation transmission device 1 on the output shaft 8 side.

  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 12 a and a rear cam surface 12 b disposed rearward of the inner ring 3 in the forward rotation direction with respect to the front cam surface 12 a. A cylindrical surface 13 radially opposed to the cam surface 12 is provided on the inner periphery of the outer ring 2.

  As shown in FIG. 4, a pair of rollers 4 a and 4 b opposed in the circumferential direction with the roller separating spring 14 interposed therebetween is incorporated between the cam surface 12 and the cylindrical surface 13. Of the pair of rollers 4a and 4b, the roller 4a on the front side in the normal direction is incorporated between the front cam surface 12a and the cylindrical surface 13, and the roller 4b on the rear side in the normal direction is the rear cam surface 12b and the cylindrical surface 13. Built in between. The rollers 4a and 4b are biased by the roller separating spring 14 in the direction in which the distance between the pair of rollers 4a and 4b is increased.

  A wedge space is formed between the cam surface 12 and the cylindrical surface 13 so as to gradually narrow from the circumferential center toward the circumferential ends. That is, the front cam surface 12a is formed such that the radial distance between the front cam surface 12a and the cylindrical surface 13 becomes gradually smaller from the position of the roller 4a toward the forward direction. The rear cam surface 12b is formed such that the radial distance between the rear cam surface 12b and the cylindrical surface 13 is gradually reduced from the position of the roller 4b toward the rear in the forward rotation direction.

Posterior cam surface 12b is composed of ridge two planes an adjacent moiety through R P _1, P ₂ extending in the axial direction. The two plane portions P ₁ and P ₂ are composed of a plane portion P ₁ on the side far from the roller separating spring 14 and a plane portion P ₂ on the side closer to the roller separating spring 14. Planar portion P ₁ and the planar portion P ₂ intersect at an angle beta (> 0) at the position of the ridge line R. Planar portion P ₁ on the side far from the roller separating spring 14, as shown in FIG. 4, the roller 4b is in contact with the roller 4b in a state in which in the engaged position. Planar portion P ₂ closer to the roller away from the spring 14, as shown in FIG. 9, the roller 4b is in contact with the roller 4b in a state in disengaged position. As shown in FIG. 9, the side of the planar portion P ₂ is a pair of rollers 4a near the roller separating spring 14 (in the figure, the direction of the spring support surface 23) direction of the reference line L connecting the centers of the 4b against the angle theta, as shown in FIG. 4, smaller than the angle (theta + beta) forming planar portion P ₁ on the side far from the roller separating spring 14 relative to the direction of the reference line L (direction of the spring support surface 23). The front cam surface 12a has the same configuration as that of the rear cam surface 12b.

  Each roller 4a, 4b is, as shown in FIG. 4, an engagement position engaged between the cylindrical surface 13 and the cam surface 12 and, as shown in FIG. 9, between the cylindrical surface 13 and the cam surface 12. It is movable in the circumferential direction between an engagement release position for releasing the engagement.

  The first roller retainer 5a holds the position of one roller 4a of the pair of rollers 4a and 4b circumferentially opposed with the roller separating spring 14 in opposition to the biasing force of the roller separating spring 14; The second roller holder 5b holds the position of the other roller 4b of the pair of rollers 4a and 4b circumferentially opposed with the roller separating spring 14 in opposition to the biasing force of the roller separating spring 14 There is.

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

  As shown in FIG. 4, the first pillar portion 15 a and the second pillar portion 15 b face each other in the circumferential direction with the pair of rollers 4 a and 4 b interposed therebetween. That is, the first column portion 15a and the second column portion 15b and the inner periphery of the outer ring 2 sandwich the pair of rollers 4a and 4b opposed in the circumferential direction with the roller separating spring 14 in between 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 disposed to face each other in the axial direction, with the second flange portion 16b closer to the inner ring 3 than the first flange portion 16a. It is done. And a plurality of notches 17 for avoiding interference with the 1st pillar part 15a of the 1st roller holder 5a are provided in the 2nd flange part 16b at intervals in the peripheral direction (refer to Drawing 7). .

  The inner periphery of the first flange portion 16 a and the inner periphery of the second flange portion 16 b are rotatably supported by cylindrical surfaces 18 provided on the outer periphery of the input shaft 7. The first flange portion 16 a is axially supported by the annular support member 20 fixed to the outer periphery of the input shaft 7 via the thrust bearing 19, whereby the 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 for holding 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 circumferentially opposed with the roller separating spring 14 therebetween. The spring holding portion 22 is attached to the inner ring 3 so that the relative position to the inner ring 3 does not change.

  As shown in FIGS. 4 and 6, the spring holding portion 22 is radially opposed to the spring support surface 23 formed between the front cam surface 12a and the rear cam surface 12b on the outer periphery of the inner ring 3. It is formed. The spring support surface 23 is a plane parallel to the direction of a reference line L (see FIG. 4) connecting the centers of the pair of rollers 4a and 4b. A recess 24 for accommodating the roller separation spring 14 is formed on the surface of the spring holder 22 facing 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 separating spring 14 by the recess 24 to prevent the roller separating spring 14 from falling off axially between the inner periphery of the outer ring 2 and the outer periphery of the inner ring 3. ing.

  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 holder actuator 6 moves relative to 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 holder 5b, an armature 27 connected to the second roller holder 5b, a rotor 28 axially opposed to the armature 27, and an armature by energization. And an electromagnet 29 for attracting the rotor 27 to the rotor 28.

  As shown in FIG. 2, the armature 27 has an annular disk portion 30 and a cylindrical portion 31 integrally formed so as to extend in the axial direction from the outer periphery of the disk portion 30. The cylindrical portion 31 of the armature 27 is fitted on the outer periphery of the outer connection ring of the second roller holder 5b with an interference, whereby the armature 27 is integrally integrally with the second roller holder 5b in the axial direction. It is connected to the 2nd roller holder 5b so that it may move. The armature 27 is rotatably and axially movably supported on the outer periphery of the input shaft 7. Here, the armature 27 is supported at two axially separated locations (ie, the inner periphery of the armature 27 and the inner periphery of the second roller holder 5b), so that the posture of the armature 27 is perpendicular to the axial direction. It is prevented from tilting.

  The rotor 28 is disposed between the armature 27 and the electromagnet 29. The rotor 28 is supported by 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 the rotor 28 with the interference to the outer periphery of the input shaft 7. The rotor 28 and the armature 27 are formed of 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 side of the input shaft 7 and retained by a retaining ring 34. A rolling bearing 35 rotatably supporting the input shaft 7 is attached to the field core 32. The electromagnet 29 energizes the solenoid coil 33 to form a magnetic path passing through the field core 32, the rotor 28 and the armature 27, thereby attracting 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 the opposite surface of the first flange 16a to the second flange 16b, and a second cam groove 36a. The second cam groove 36b is provided on the surface of the flange portion 16b opposite to the first flange portion 16a, and the ball 37 is interposed between the first cam groove 36a and the second cam groove 36b. The first cam groove 36 a and the second cam groove 36 b are each formed to extend in the circumferential direction. Further, the first cam groove 36 a is formed to have a groove bottom inclined so as to be gradually deeper in one circumferential direction from the contact position with the ball 37, and the second cam groove 36 b also corresponds to the ball 37. It is configured to have a groove bottom inclined so as to become gradually deeper from the contact position toward the other circumferential direction. 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.

  In the motion conversion mechanism 26, when the second flange portion 16b moves in the axial direction toward the first flange portion 16a, the ball 37 rolls along the cam grooves 36a and 36b, whereby the first roller holder is moved. 5a and the second roller holder 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 the pair of rollers 4a and 4b in a direction in which the distance between them is narrowed.

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

  As shown in FIG. 1, when the energization of the electromagnet 29 is stopped, the rotation transmission device 1 is in the engaged state in which the rotation is transmitted between the outer ring 2 and the inner ring 3. That is, when the energization of the electromagnet 29 is stopped, the armature 27 is in a state of being separated from the rotor 28 by the force of the roller separation spring 14. At this time, as shown in FIG. 4, the roller 4a on the front side in the forward direction is driven by the force of the roller separating spring 14 which presses the rollers 4a and 4b in the direction in which the distance between the pair of rollers 4a and 4b increases. Between the cylindrical surface 13 on the inner periphery of the outer ring 2 and the front cam surface 12 a on the outer periphery of the inner ring 3, and the rear roller 4 b in the forward rotation direction is the cylindrical surface on the inner periphery of the outer ring 2 It is in a state of being engaged and waiting between 13 and the rear cam surface 12 b on the outer periphery of the inner ring 3. In this state, when the inner ring 3 rotates in the normal direction, the rear roller 4b in the normal direction engages between the cylindrical surface 13 and the rear cam surface 12b, and the inner ring 3 to the outer ring 2 through the roller 4b. The rotation is transmitted to Further, when the inner ring 3 rotates in the reverse direction, the roller 4a on the front side in the normal 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 through the roller 4a. Do.

  On the other hand, when the electromagnet 29 of FIG. 1 is energized, the rotation transmission device 1 is in the idle state in which the transmission of the 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 in conjunction with the operation of the armature 27, the second flange portion 16b moves in the axial direction toward the first flange portion 16a. At this time, when the ball 37 of the motion conversion mechanism 26 rolls along the cam grooves 36a and 36b, the first roller holder 5a and the second roller holder 5b relatively rotate. Then, due to the relative rotation of the first roller holder 5a and the second roller holder 5b, as shown in FIG. 9, the distance between the pair of rollers 4a and 4b between the first column 15a and the second column 15b. The rollers 4a and 4b are pressed in the direction in which they narrow, and as a result, the engagement standby state of the roller 4a on the front side in the normal direction (a small gap exists between the roller 4a on the front side in the normal direction and the cylindrical surface 13 When the inner ring 3 rotates in the reverse direction, the roller 4a is immediately engaged between the cylindrical surface 13 and the front cam surface 12a), and the engagement standby state of the rear roller 4b in the forward direction ( There is a minute gap between the roller 4b on the rear side in the forward direction and the cylindrical surface 13, but when the inner ring 3 rotates in the forward 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 idles.

  By the way, in the idle state shown in FIG. 9, when vibration is applied to the rotation transmission device 1, the rollers 4a, 4b move to the outer diameter side by the vibration and contact the cylindrical surface 13 of the inner periphery of the outer ring 2, There is a possibility that the rollers 4a and 4b may move to the outer diameter side and contact the cylindrical surface 13 of the inner periphery of the outer ring 2 by the centrifugal force acting on the 4a and 4b. When the rollers 4a and 4b come into contact with the cylindrical surface 13 on the inner periphery of the outer ring 2, the rollers 4a and 4b get caught between the cylindrical surface 13 and the cam surface 12 to cause a problem of mis-engagement.

In response to such a problem, in the rotation transmission device 1, the rollers 4a and 4b are disengaged as shown in FIG. 9 with respect to the direction of the reference line L connecting the centers of the pair of rollers 4a and 4b. roller 4a in the state at the position, the angle of the planar portion P ₂ in contact with 4b theta is roller 4a as shown in FIG. 4, 4b are rollers 4a in a state in which the engaged position, the planar portion P ₁ in contact with 4b It is formed to be smaller than the formed angle (θ + β). Thus, as shown in FIG. 10, if the roller 4a in the engaged position, the roller 4a in the planar portion P ₁ and the disengaged position in contact with 4b, and the planar portion P ₂ in contact with 4b coplanar compared to, as shown in FIG. 9, the roller 4a in the engaged position, while maintaining the angle of the planar portion P ₁ adjacent to 4b the (θ + β) to the appropriate size, the roller 4a in the disengaged position , 4 b to the cylindrical surface 13 on the inner periphery of the outer ring 2 can be set large. That is, the first column portion 15a and the second column portion 15b move in the direction in which the distance between the pair of rollers 4a and 4b is narrowed, and the engagement of the rollers 4a and 4b between the cam surface 12 and the cylindrical surface 13 is released. Even when the distance D between the first column portion 15a and the second column portion 15b is the same, the gap T from the rollers 4a and 4b to the cylindrical surface 13 on the inner periphery of the outer ring 2 is set large. (The relationship of T> T 'is established between the gap T shown in FIG. 9 and the gap T' shown in FIG. 10). Therefore, as shown in FIG. 9, when the rollers 4a and 4b are in the engagement release position, even if vibration or centrifugal force acts on the rollers 4a and 4b, the rollers 4a and 4b have the cylindrical surface 13 of the inner periphery of the outer ring 2. It is difficult to contact the rollers 4a and 4b, and the mis-engagement of the rollers 4a and 4b can be prevented.

Further, the rotation transmitting device 1, the roller 4a, the roller 4a in a state in which 4b is in the engaged position, the portion _{P 1} of the cam surface 12 in contact with 4b, the roller in a state in which the roller 4a, 4b is in the disengaged position 4a, since the portion P ₂ of the cam surface in contact with 4b is a both planes, it is possible to accurately machining the two parts P _1, P _2.

11 and 12 show modified examples of the cam surface 12 of the above embodiment. Front cam surface 12a, a pair of rollers 4a, 4b and planar portion P ₁ in contact with the roller 4a in the state in the engaged position, the plane where the pair of rollers 4a, 4b are in contact with the roller 4a in the presence of the disengaged position consisting of part _{P 2} Metropolitan. Posterior cam surface 12b is also a pair of rollers 4a, 4b and planar portion P ₁ in contact with the roller 4b in the state in the engaged position, the plane where the pair of rollers 4a, 4b are in contact with the roller 4b in a state in disengaged position consisting of part _{P 2} Metropolitan. Here, the planar portion P ₂ of the planar portion P ₂ and the rear cam surface 12b of the front cam surface 12a is disposed on the same plane. In this way, it is possible to set the gap from the rollers 4a and 4b to the cylindrical surface 13 on the inner periphery of the outer ring 2 more effectively larger when the rollers 4a and 4b are in the engagement release position. . In addition, the dashed-two dotted line of FIG. 11 has shown the shape of the inner ring | wheel 3 of the conventional rotation transmission apparatus.

In FIG. 13, the other modification of the cam surface 12 of the said embodiment is shown. Front cam surface 12a, a pair of rollers 4a, the planar portion P ₁ to 4b is in contact with the roller 4a in the state in the engaged position, the arc in which the pair of rollers 4a, 4b are in contact with the roller 4a in the presence of the disengaged position consisting of surface portion _{P 3} Metropolitan. Arcuate surface portion P ₃ is formed in a convex circular arc cross sectional shape toward the outer diameter side, it is continuous smoothly with the planar portion P _1. Posterior cam surface 12b, similarly a front cam surface 12a, a planar portion _{P 1} of the pair of rollers 4a, 4b are in contact with the roller 4b in the state in the engaged position, the pair of rollers 4a, 4b are in the disengaged position formed of circularly arcuate surfaces portions P ₃ Metropolitan in contact with the roller 4b in the state. Thus, the roller 4a, with 4b to ensure the machining accuracy of portions P ₁ in contact with the rollers 4a, 4b in a state in which in the engaged position, the roller 4a between the engaged position and the disengaged position, It is possible to make the movement of 4b smooth.

  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.

  This vehicle steering apparatus includes a steering wheel 40, a steering actuator 42 for moving a pair of wheels 41 so that the direction of the pair of left and right wheels 41 changes in accordance with the steering angle of the steering wheel 40, the steering wheel 40 and It has the rotation transmission device 1 incorporated in the middle of the rotation transmission path between the rudder actuators 42. The rotation transmission device 1 shuts off the transmission of rotation between the steering wheel 40 and the steering actuator 42 when normal, and transmits the rotation between the steering wheel 40 and the steering actuator 42 when an abnormality such as power loss occurs. Function as a backup clutch. The steering wheel 40 is connected to a reaction force actuator 43 that applies a steering reaction force to the steering wheel 40 according to the behavior of the vehicle.

  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 coupling 44, and the output shaft 8 is connected to the shaft 47 on the steering actuator 42 via the shaft coupling 46. ing.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

Reference Signs List 1 rotation transmission device 2 outer ring 3 inner ring 4a, 4b roller 5a first roller holder 5b second roller holder 6 holder actuator 7 input shaft 8 output shaft 12 cam surface 13 cylindrical surface 14 roller separation spring 26 motion conversion mechanism 27 armature 28 Rotor 29 Electromagnet 40 Steering wheel 41 Wheel 42 Steering actuator L Reference line P ₁ , P ₂ , P ₃ A portion of the cam surface

Claims (3)

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) rotatably supported relative to the inner ring (3);
An output shaft (8) connected to the outer ring (2) 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 which narrows gradually from the circumferential center to both circumferential ends from the circumferential center with the cylindrical surface (13);
A pair of rollers (4a, 4b) circumferentially installed facing each other between the cylindrical surface (13) and the cam surface (12);
A roller separating spring (14) for urging the rollers (4a, 4b) in a direction to widen the distance between the pair of rollers (4a, 4b);
It is a plane parallel to the direction of a reference line (L) connecting the centers of the pair of rollers (4a, 4b), provided on the outer periphery of the inner ring (3) to support the roller separation spring (14). A spring support surface (23),
A first roller holder (5a) for holding the position of one of the pair of rollers (4a, 4b) against the biasing force of the roller separation spring (14);
A second roller holder (5b) for holding the position of the other roller (4b) of the pair of rollers (4a, 4b) against the biasing force of the roller separation spring (14);
An engagement position where the pair of rollers (4a, 4b) is engaged between the cylindrical surface (13) and the cam surface (12), and the pair of rollers (4a, 4b) are the cylindrical surface (13) And the second roller holder (5a) and the second to move the pair of rollers (4a, 4b) between the cam surface (12) and the engagement release position for releasing the engagement. And a holder actuator (6) for relatively moving the roller holder (5b).
The cam surface (12) ,
A first contact with each roller (4a, 4b) with the pair of rollers (4a, 4b) in the engagement release position, and intersecting with the spring support surface (23) at a first angle (θ) Plane portion (P ₂ ) of
The rollers (4a, 4b) are in contact with the rollers (4a, 4b) with the pair of rollers (4a, 4b) in the engaged position, and intersect with the first plane portion (P ₂ ) at a second angle (β) A second plane portion (P ₁ ),
The outer periphery of the inner ring (3) has a three-surface configuration of the spring support surface (23), the first flat portion (P ₂ ), and the second flat portion (P ₁ ),
The part in contact with the roller (4a, 4b) with the roller (4a, 4b) in the disengagement position with respect to the direction of the reference line (L) connecting the centers of the pair of rollers (4a, 4b) _{(P 2)} the angle of the (theta), the roller (4a, 4b) is's go smaller than the angle (θ + β) formed between the portion in contact with the rollers in a state that in the engaged position _{(4a, 4b) (P 1} ) And a rotation transmission device characterized by The cage actuator (6) is
When the first roller holder (5a) and the second roller holder (5b) move relative to each other in the axial direction, the axial relative movement is carried out by the first roller holder (5a) and the second roller holder ( 5b) motion conversion mechanism (26) for converting to relative rotation;
An armature (27) connected so as to move axially integrally with one of the first roller holder (5a) and the second roller holder (5b);
A rotor (28) disposed axially opposite the armature (27);
The rotation transmission device according to claim 1 , comprising an electromagnet (29) for attracting the armature (27) to the rotor (28) by energization. With the steering wheel (40),
A steering actuator (42) that moves the pair of wheels (41) such that the direction of the pair of left and right wheels (41) changes according to the steering angle of the steering wheel (40);
At normal times, transmission of rotation is cut off between the steering wheel (40) and the steering actuator (42), and at abnormal times, 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),
A steering apparatus of a steer-by-wire system, wherein the rotation transmission apparatus according to claim 1 or 2 is used as the rotation transmission apparatus (1).

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