Rotational transmission device

Abstract

To provide a rotation transmission device capable of making an installation space small in an axial direction.SOLUTION: A rotation transmission device includes a roller holder 7 supported between the outer periphery of an inner ring 5 and the inner periphery of an outer ring 4 movably in the peripheral direction, an armature 10 arranged opposed to an electromagnet 9 in the axial direction so as to be moved in the axial direction when energizing the electromagnet 9, and an operation conversion mechanism 11 for moving the roller holder 7 in the peripheral direction in response to the movement of the armature 10 in the axial direction. The electromagnet 9 is formed to have an inner diameter larger than the outer diameter of the outer ring 4, and the electromagnet 9 is arranged on the radial outside of the outer ring 4 to encircle the outer periphery of the outer ring 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a rotational transmission device used for switching the transmission and interruption of rotation.

Background Art

[0002] As a rotational transmission device that switches between a fastening state in which rotation is transmitted between an inner ring and an outer ring and an idle state in which the transmission of rotation between the inner ring and the outer ring is interrupted, for example, the one described in Patent Document 1 is known.

[0003] The rotational transmission device described in Patent Document 1 has a roller clutch portion and an electromagnetic clutch portion arranged side by side in the axial direction. The roller clutch portion includes an outer ring, an inner ring disposed radially inside the outer ring, rollers incorporated between the inner circumference of the outer ring and the outer circumference of the inner ring, an engagement position for engaging the rollers between the outer circumference of the inner ring and the inner circumference of the outer ring, and a roller holder supported so as to be circumferentially movable between the engagement release position for releasing the engagement of the rollers between the outer circumference of the inner ring and the inner circumference of the outer ring. Further, the electromagnetic clutch portion includes an annular electromagnet, an armature arranged axially opposite to the electromagnet so as to move axially when the electromagnet is energized, and an operation conversion mechanism for circumferentially moving the roller holder of the roller clutch portion from the engagement release position to the engagement position in accordance with the axial movement of the armature.

[0004] When the electromagnet of the rotational transmission device of Patent Document 1 is energized, the rollers engage between the outer circumference of the inner ring and the inner circumference of the outer ring, and a fastening state is achieved in which rotation is transmitted between the inner ring and the outer ring. On the other hand, when the energization of the electromagnet is released, the engagement of the rollers between the outer circumference of the inner ring and the inner circumference of the outer ring is released, and an idle state is achieved in which the transmission of rotation between the inner ring and the outer ring is interrupted.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The rotary transmission device described in Patent Document 1 transmits torque by engaging rollers (engineers) between the outer circumference of the inner ring and the inner circumference of the outer ring, which has the advantage of being able to transmit a large amount of torque. However, because the roller clutch section and the electromagnetic clutch section are arranged side by side in the axial direction, the axial dimension of the rotary transmission device is long, requiring a long installation space in the axial direction.

[0007] The problem that this invention aims to solve is to provide a rotational transmission device that can minimize the installation space required in the axial direction. [Means for solving the problem]

[0008] To solve the above problems, this invention provides a rotational transmission device with the following configuration. [Configuration 1] Outer ring and, An inner ring is positioned radially inward of the outer ring and is supported so as to be rotatable relative to the outer ring, An engaging element is incorporated between the inner circumference of the outer ring and the outer circumference of the inner ring, An engaging element retainer is supported so as to be movable in the circumferential direction between an engaging position in which the engaging element is engaged between the outer circumference of the inner ring and the inner circumference of the outer ring, and an disengagement position in which the engaging element is released from the outer circumference of the inner ring and the inner circumference of the outer ring. A ring-shaped electromagnet, An armature is positioned opposite the electromagnet in the axial direction so as to move in the axial direction when the electromagnet is energized, A rotational transmission device having an action conversion mechanism that moves the engaging element retainer circumferentially from one of the engaged position and the disengaged position to the other in accordance with the axial movement of the armature, A rotational transmission device characterized in that the electromagnet is formed to have an inner diameter larger than the outer diameter of the outer ring, and the electromagnet is arranged radially outward of the outer ring so as to surround the outer circumference of the outer ring.

[0009] By adopting this configuration, the electromagnets are formed to have an inner diameter larger than the outer diameter of the outer ring, and these electromagnets are positioned radially outward around the outer circumference of the outer ring. Compared to a configuration where the electromagnets and outer ring are arranged axially so as not to overlap when viewed radially, the axial length of the rotational transmission device can be shortened by the amount by which the electromagnets and outer ring overlap when viewed radially. Therefore, the axial installation space required for the rotational transmission device can be kept small.

[0010] [Configuration 2] The device further includes a switch spring that elastically holds the engaging element retainer in the disengaged position. The engagement element holder is a cylindrical member having a pocket for housing the engagement element. The rotation transmission device according to configuration 1, wherein the switch spring comprises a first switch spring that engages with a first spring engagement portion formed on one axial side of the pocket of the engaging element retainer, and a second switch spring that engages with a second spring engagement portion formed on the other axial side of the pocket of the engaging element retainer.

[0011] With this configuration, the switch spring that elastically holds the engager retainer in the disengaged position is composed of multiple springs (a first switch spring and a second switch spring), allowing the engager retainer to be held in the disengaged position with a large spring force. Therefore, when the inner ring accelerates or decelerates with a large acceleration while the engager retainer is in the disengaged position, releasing the engagement of the engager between the outer circumference of the inner ring and the inner circumference of the outer ring, it is possible to prevent the engager retainer from moving circumferentially relative to the inner ring in conjunction with the acceleration or deceleration of the inner ring, thereby preventing the engager from misengaging between the inner circumference of the outer ring and the outer circumference of the inner ring.

[0012] [Configuration 3] The rotational transmission device according to configuration 2, wherein the first spring engaging portion and the second spring engaging portion are arranged in a positional relationship of 180° opposite to each other when viewed from the axial direction.

[0013] When this configuration is adopted, the spring force of the first switch spring and the spring force of the second switch spring act on the engagement retainer at positions that are 180° apart from each other when viewed axially. Therefore, it is possible to prevent the axis of the engagement retainer from deviating from the axis of the inner ring, and the operation of the engagement retainer can be made stable.

[0014] [Configuration 4] It further has a separating spring that biases the armature in the axial direction away from the electromagnet. The armature is rotationally locked to the engagement retainer so as to rotate integrally with the engagement retainer. A rotational transmission device according to any one of Configurations 1 to 3, wherein one axial end of the separating spring abuts on the armature, and the other axial end of the separating spring is supported by a spring receiving member provided so as to rotate integrally with the inner ring.

[0015] When this configuration is adopted, since the separating spring is supported by the spring receiving member that rotates integrally with the inner ring, it is possible to prevent the separating spring from wearing due to rotational sliding during the idling state, and sufficient durability can be ensured even when used at high speeds.

[0016] [Configuration 5] It further has an annular rotor that is fixed to the outer ring so as to rotate integrally with the outer ring and is disposed between the armature and the electromagnet. A rotational transmission device according to Configuration 4, wherein the spring receiving member is disposed radially inside the rotor.

[0017] When this configuration is adopted, since the spring receiving member is disposed radially inside the rotor, the rotational transmission device becomes compact.

[0018] [Configuration 6] [[ID=3^2]]A rotational transmission device according to any one of Configurations 1 to 5, wherein the electromagnet and the outer ring are disposed on the same axial side with respect to the armature.

Advantages of the Invention

[0019] The rotational transmission device of this invention forms an electromagnet so as to have an inner diameter dimension larger than the outer diameter dimension of the outer ring, and arranges the electromagnet on the outer side in the radial direction of the outer ring so as to surround the outer periphery of the outer ring. Therefore, compared with an arrangement in which the electromagnet and the outer ring are arranged side by side in the axial direction so as not to overlap when viewed from the radial direction, the axial length of the rotational transmission device can be shortened by the amount by which the electromagnet and the outer ring overlap when viewed from the radial direction. For this reason, the installation space in the axial direction of the rotational transmission device can be kept small.

Brief Description of the Drawings

[0020] [Figure 1] Cross-sectional view showing the rotational transmission device according to an embodiment of this invention [Figure 2] Right side view of FIG. 1 [Figure 3] Enlarged cross-sectional view of the vicinity of the roller clutch portion of the rotational transmission device of FIG. 1 [Figure 4] Cross-sectional view taken along line IV-IV of FIG. 3 [Figure 5] Cross-sectional view taken along line V-V of FIG. 3 [Figure 6] Exploded perspective view of the vicinity of the roller retainer of FIG. 3 [Figure 7] Diagram schematically showing an example of a drive device using the rotational transmission device of FIG. 1

Mode for Carrying Out the Invention

[0021] FIG. 1 shows a rotational transmission device M according to an embodiment of this invention. This rotational transmission device M has a roller clutch portion 1, an electromagnetic clutch portion 2 for switching between the fastened state and the idling state of the roller clutch portion 1, and a housing 3 that houses the roller clutch portion 1 and the electromagnetic clutch portion 2.

[0022] The roller clutch section 1 includes an outer ring 4, an inner ring 5 positioned radially inward of the outer ring 4, a roller 6 incorporated between the inner circumference of the outer ring 4 and the outer circumference of the inner ring 5, a roller retainer 7 supported to be circumferentially movable between an engagement position in which the roller 6 engages between the outer circumference of the inner ring 5 and the inner circumference of the outer ring 4, and an engagement release position in which the engagement of the roller 6 between the outer circumference of the inner ring 5 and the inner circumference of the outer ring 4 is released, and a switch spring 8 that elastically holds the roller retainer 7 in the engagement release position. On the other hand, the electromagnetic clutch section 2 includes an annular electromagnet 9 positioned radially outward of the outer ring 4, an armature 10 positioned axially opposite to the electromagnet 9 so as to move axially when the electromagnet 9 is energized, and an operation conversion mechanism 11 that moves the roller retainer 7 circumferentially in accordance with the axial movement of the armature 10.

[0023] The input shaft 12 is integrally formed with the inner ring 5. Alternatively, the input shaft 12 may be formed as a separate component from the inner ring 5, and the two may be joined by a serrated fitting or the like so that they rotate together. The housing 3 has a cylindrical portion 13 arranged to surround the radially outer side of the electromagnet 9, and an inward-facing flange portion 14 extending radially inward from one axial end of the cylindrical portion 13. An input-side bearing 15 that rotatably supports the input shaft 12 is incorporated into the inner circumference of the inward-facing flange portion 14. The housing 3 also has a plurality of mounting pieces 16 (see Figure 2) extending radially outward from one axial end of the cylindrical portion 13.

[0024] The output shaft 17 is integrally formed with the outer ring 4. Alternatively, the output shaft 17 may be formed as a separate component from the outer ring 4, and the two may be joined by a serrated fitting or the like so that they rotate together. The output shaft 17 is rotatably supported by an output-side bearing 18 assembled on the inner circumference of the electromagnet 9. An intermediate bearing 19 is incorporated on the inner circumference of the outer ring 4 to support the inner ring 5 so that it can rotate relative to the outer ring 4. The input shaft 12, inner ring 5, outer ring 4, and output shaft 17 are all arranged coaxially.

[0025] As shown in Figures 3 and 4, multiple cam surfaces 20 are provided at equal intervals in the circumferential direction on the outer circumference of the inner ring 5. A cylindrical surface 21 is provided on the inner circumference of the outer ring 4, facing the cam surfaces 20 in the radial direction. The cam surfaces 20 are surfaces that form a wedge space between themselves and the cylindrical surface 21, which gradually narrows from the circumferential center to both ends in the circumferential direction; for example, they are flat surfaces facing the cylindrical surface 21 in the radial direction. As shown in Figure 4, one roller 6 is incorporated between each cam surface 20 and the cylindrical surface 21.

[0026] The roller holder 7 is a cylindrical member having multiple radially penetrating pockets 22 (see Figure 3) formed at circumferential intervals, with a roller 6 housed in each of the pockets 22. The roller holder 7 is supported so as to be circumferentially movable with respect to the inner ring 5, between an engagement position in which the roller 6 is engaged between the cam surface 20 and the cylindrical surface 21 by moving the roller 6 circumferentially from the circumferential center of the cam surface 20, and an engagement release position in which the engagement of the roller 6 between the cam surface 20 and the cylindrical surface 21 is released by moving the roller 6 to the circumferential center of the cam surface 20.

[0027] As shown in Figure 3, the switch spring 8 consists of a first switch spring 8a that engages with a first spring engagement portion 23 (see Figure 4) formed on one axial side (left side in the figure) of the pocket 22 of the roller holder 7, and a second switch spring 8b that engages with a second spring engagement portion 24 (see Figure 5) formed on the other axial side (right side in the figure) of the pocket 22 of the roller holder 7.

[0028] As shown in Figure 4, the first switch spring 8a consists of a C-shaped annular portion 25 formed by winding a steel wire in a C shape, and a pair of extension portions 26 extending radially outward from both ends of the C-shaped annular portion 25. The C-shaped annular portion 25 is fitted into a circular first spring housing recess 27 formed on one axial end face of the inner ring 5. The pair of extension portions 26 are inserted into a first radial groove 28 formed on one axial end face of the inner ring 5 so as to penetrate radially outward from the first spring housing recess 27.

[0029] The extension 26 of the first switch spring 8a protrudes from the radially outer end of the first radial groove 28, and the portion of the extension 26 protruding from the first radial groove 28 engages with a first spring engagement portion 23 formed at one axial end of the roller retainer 7. The first spring engagement portion 23 is a recess having the same circumferential width as the first radial groove 28. The extension 26 of the first switch spring 8a is in contact with the inner surface of the first radial groove 28 and the inner surface of the first spring engagement portion 23, respectively, and the circumferential force acting on this contact portion elastically holds the roller retainer 7 in the disengaged position. That is, when the roller retainer 7 moves from the disengaged position shown in Figure 4 to the engaged position by circumferential relative displacement with respect to the inner ring 5, the elastic restoring force of the first switch spring 8a biases the roller retainer 7 in the direction of returning to the disengaged position.

[0030] As shown in Figure 5, the second switch spring 8b, like the first switch spring 8a, consists of a C-shaped annular portion 29 made by winding steel wire in a C shape, and a pair of extensions 30 extending radially outward from both ends of the C-shaped annular portion 29. The C-shaped annular portion 29 is fitted into a circular second spring housing recess 31 formed on the other axial end face of the inner ring 5. The pair of extensions 30 are inserted into a second radial groove 32 formed on the other axial end face of the inner ring 5 so as to penetrate radially outward from the second spring housing recess 31.

[0031] The extension 30 of the second switch spring 8b protrudes from the radially outer end of the second radial groove 32, and the portion of the extension 30 protruding from the second radial groove 32 engages with a second spring engagement portion 24 formed at the other axial end of the roller retainer 7. The second spring engagement portion 24 is a recess having the same circumferential width as the second radial groove 32. The extension 30 of the second switch spring 8b is in contact with the inner surface of the second radial groove 32 and the inner surface of the second spring engagement portion 24, and the circumferential force acting on this contact portion elastically holds the roller retainer 7 in the disengaged position. That is, when the roller retainer 7 moves from the disengaged position shown in Figure 5 to the engaged position by circumferential relative displacement with respect to the inner ring 5, the elastic restoring force of the second switch spring 8b biases the roller retainer 7 in the direction of returning to the disengaged position.

[0032] As shown in Figures 4 and 6, the first spring engagement portion 23 and the second spring engagement portion 24 of the roller retainer 7 are positioned 180° opposite to each other when viewed from the axial direction. As a result, the circumferential position of the portion where the spring force acts from the first switch spring 8a to the roller retainer 7 and the circumferential position of the portion where the spring force acts from the second switch spring 8b to the roller retainer 7 are on opposite sides of the center of the roller retainer 7 when viewed from the axial direction.

[0033] As shown in Figure 3, the armature 10 is supported by a cylindrical surface 33 formed on the outer circumference of the input shaft 12 so as to be rotatable and axially movable relative to the inner ring 5. The armature 10 is a disc-shaped member made of a magnetic material (iron, silicon steel, etc.). The armature 10 is positioned opposite the inward flange portion 14 in the axial direction. Also, the electromagnet 9 (see Figure 1) and the outer ring 4 are positioned on the same axial side of the armature 10 (opposite the side facing the inward flange portion 14; the right side in the figure).

[0034] As shown in Figure 1, the electromagnet 9 has an annular field core 34 made of a magnetic material and a solenoid coil 35 wound around the field core 34. The field core 34 has a C-shaped cross-section that is open axially toward the armature 10. The field core 34 is fitted and fixed to the inner circumference of the cylindrical portion 13 of the housing 3. Here, the electromagnet 9 is formed to have an inner diameter that is larger than the outer diameter of the outer ring 4 and is positioned radially outward of the outer ring 4 so as to surround the outer circumference of the outer ring 4.

[0035] An annular rotor 36 is provided between the armature 10 and the electromagnet 9. The rotor 36 has an inner cylinder portion 37 facing the radially inward side of the electromagnet 9, an outer cylinder portion 38 facing the radially outward side of the electromagnet 9, and an annular plate portion 39 that connects the inner cylinder portion 37 and the outer cylinder portion 38 by passing between the axially opposing surfaces of the armature 10 and the electromagnet 9. The inner cylinder portion 37 is fitted to the outer circumference of the outer ring 4 with an overlap. This fitting of the inner cylinder portion 37 fixes the rotor 36 to the outer ring 4 so that it rotates integrally with the outer ring 4. The inner cylinder portion 37, outer cylinder portion 38, and annular plate portion 39 of the rotor 36 are integrally formed from a magnetic material (iron, silicon steel, etc.). Multiple through holes 40 that penetrate in the axial direction are formed in the annular plate portion 39 of the rotor 36 at intervals in the circumferential direction. The through hole 40 has an elongated shape that extends circumferentially through the annular plate portion 39 of the rotor 36.

[0036] When current is applied to the electromagnet 9 (solenoid coil 35), a magnetic circuit is formed passing through the field core 34, rotor 36, and armature 10, causing the armature 10 to move axially toward the field core 34 and become attracted to the annular plate portion 39 of the rotor 36.

[0037] As shown in Figure 1, a separation spring 41 is provided on the radially inner side of the rotor 36 to bias the armature 10 in the axial direction away from the electromagnet 9 (left side in the figure). The separation spring 41 is an annular spring member arranged coaxially with the input shaft 12 and is incorporated between the armature 10 and the spring receiving member 42 in a compressed state in the axial direction. For example, a wave washer, disc spring, or compression coil spring can be used as the separation spring 41. One axial end of the separation spring 41 abuts against the side of the armature 10 facing the electromagnet 9 (right side in the figure), and the other axial end of the separation spring 41 is supported by the spring receiving member 42.

[0038] As shown in Figure 3, the spring support member 42 is pressed against the intermediate plate 43 (described later) by the axial reaction force received from the separation spring 41, and when it is free-rotating, the frictional force acting between the spring support member 42 and the intermediate plate 43 causes the spring support member 42 to rotate integrally with the inner ring 5. Here, an example has been given in which the separation spring 41 is supported by the spring support member 42 which is formed separately from the intermediate plate 43, but the spring support member 42 and the intermediate plate 43 may be made as a single integrated member.

[0039] As shown in Figure 3, the armature 10's axial movement away from the electromagnet 9 (left side in the figure) is restricted by a retaining ring 44 mounted on the outer circumference of the input shaft 12. The armature 10 is also pressed against the retaining ring 44 by the spring force of the separation spring 41.

[0040] As shown in Figure 1, the motion conversion mechanism 11 includes a rotor 36 provided between the armature 10 and the electromagnet 9 and fixed to the outer ring 4 so as to rotate integrally with the outer ring 4, and an intermediate plate 43 fixed to the armature 10 and fixed to the roller holder 7 so as to be axially movable relative to the armature 10.

[0041] As shown in Figures 3 and 6, the outer circumference of the intermediate plate 43 has an engaging projection 46 that engages with an engaging recess 45 formed at one axial end of the roller holder 7. The intermediate plate 43 is prevented from rotating by the roller holder 7 by the engagement of the engaging projection 46 and the engaging recess 45, so as not to move circumferentially together with the roller holder 7.

[0042] Furthermore, the intermediate plate 43 has an axial projection 47 that extends axially toward the armature 10. The armature 10 has an axial hole 48 into which the axial projection 47 of the intermediate plate 43 is slidably inserted in the axial direction. The intermediate plate 43 is prevented from rotating by the engagement of the axial projection 47 and the axial hole 48, so that the armature 10 can move circumferentially together with the armature 10 while being able to move axially relative to the intermediate plate 43. Here, the armature 10 is prevented from rotating by the roller holder 7 via the intermediate plate 43 and rotates together with the roller holder 7.

[0043] In this motion conversion mechanism 11, when the armature 10 shown in Figure 1 moves axially toward the electromagnet 9 and makes contact with the rotor 36, the frictional force acting between the armature 10 and the rotor 36 and the difference in rotational speed cause the armature 10 to rotate relative to the inner ring 5. The roller retainer 7, which is prevented from rotating by the armature 10 via the intermediate plate 43, also rotates relative to the inner ring 5. As a result, the roller retainer 7 moves circumferentially from the disengaged position to the engaged position against the spring force of the first switch spring 8a and the second switch spring 8b.

[0044] An example of the operation of the above-mentioned rotary transmission device M will be explained.

[0045] When the electromagnet 9 shown in Figure 1 is de-energized, the inner ring 5 enters a disengaged state (free-spinning state) where it can rotate freely relative to the outer ring 4. That is, when the electromagnet 9 is not energized, the armature 10 separates from the rotor 36 due to the spring force of the separation spring 41, and the armature 10 becomes able to rotate freely relative to the rotor 36. At this time, the roller retainer 7 is held in the disengaged position by the switch spring 8, so even if the inner ring 5 is rotated, the roller 6 does not engage between the cam surface 20 on the outer circumference of the inner ring 5 and the cylindrical surface 21 on the inner circumference of the outer ring 4, as shown in Figures 3 to 5, and the transmission of rotation between the inner ring 5 and the outer ring 4 is interrupted, resulting in a free-spinning state.

[0046] On the other hand, when the electromagnet 9 shown in Figure 1 is energized, a fastened state is achieved in which rotation is transmitted between the inner ring 5 and the outer ring 4. That is, when the electromagnet 9 is energized, the armature 10 is attracted to the rotor 36, and the armature 10 is in frictional contact with the rotor 36. At this time, when the inner ring 5 is rotated, the armature 10, which is in frictional contact with the electromagnet 9, is prevented from rotating by the roller retainer 7 via the intermediate plate 43, so the rotation of the roller retainer 7 is restricted, and the inner ring 5 rotates relative to the roller retainer 7. As a result, the roller retainer 7 moves from the disengaged position to the engaged position against the spring force of the switch spring 8, and the roller 6 engages between the cam surface 20 on the outer circumference of the inner ring 5 and the cylindrical surface 21 on the inner circumference of the outer ring 4, as shown in Figures 3 to 5, thus creating a fastened state in which rotation is transmitted between the inner ring 5 and the outer ring 4.

[0047] As shown in Figure 1, the rotational transmission device M has an electromagnet 9 with an inner diameter larger than the outer diameter of the outer ring 4, and the electromagnet 9 is positioned radially outside the outer ring 4 so as to surround its outer circumference. Compared to a configuration where the electromagnet 9 and the outer ring 4 are arranged axially side by side so as not to overlap when viewed radially, the axial length of the rotational transmission device M can be shortened by the amount by which the electromagnet 9 and the outer ring 4 overlap when viewed radially. Therefore, the axial installation space required for the rotational transmission device M can be kept small.

[0048] Furthermore, in this rotation transmission device M, the switch spring 8 that elastically holds the roller retainer 7 in the disengaged position is composed of multiple springs (a first switch spring 8a and a second switch spring 8b), as shown in Figure 3, so that the roller retainer 7 can be held in the disengaged position with a large spring force.Therefore, when the inner ring 5 is accelerated or decelerated with a large acceleration while the roller retainer 7 is in the disengaged position, disengaging the roller 6 between the outer circumference of the inner ring 5 and the inner circumference of the outer ring 4, it is possible to prevent the roller retainer 7 from moving circumferentially relative to the inner ring 5 in accordance with the acceleration or deceleration of the inner ring 5.Therefore, even when used at high speeds, it is possible to prevent the roller 6 from misengaging between the inner circumference of the outer ring 4 and the outer circumference of the inner ring 5, making it suitable for high-speed rotation applications.

[0049] Furthermore, as shown in Figure 4, in this rotation transmission device M, the spring force of the first switch spring 8a and the spring force of the second switch spring 8b act on the roller retainer 7 at positions 180° opposite to each other when viewed from the axial direction. This prevents the axis of the roller retainer 7 from shifting from the axis of the inner ring 5, and ensures stable operation of the roller retainer 7.

[0050] Furthermore, in this rotational transmission device M, the separation spring 41 is supported by a spring receiving member 42 that rotates integrally with the inner ring 5 when it is free-spinning. This prevents the separation spring 41 from wearing down due to rotational sliding when it is free-spinning, ensuring sufficient durability even when used at high speeds.

[0051] Furthermore, since the spring support member 42 is positioned radially inward of the rotor 36, the rotational transmission device M is compact.

[0052] In the above embodiment, an example was given in which a roller 6 is incorporated as an engaging element between the inner circumference of the outer ring 4 and the outer circumference of the inner ring 5. However, this invention can be similarly applied to rotational transmission devices that use balls, sprags, or the like as engaging elements.

[0053] Furthermore, in the above embodiment, the motion conversion mechanism 11 is designed to move the roller retainer 7 from the disengaged position to the engaged position in accordance with the axial movement of the armature 10 in the direction approaching the electromagnet 9 (that is, a forward-acting type rotation transmission device M is employed that is disengaged when de-energized and engaged when energized). However, the motion conversion mechanism 11 may also be designed to move the roller retainer 7 from the engaged position to the disengaged position in accordance with the axial movement of the armature 10 in the direction approaching the electromagnet 9 (that is, a reverse-acting type rotation transmission device M is employed that is engaged when de-energized and disengaged when energized). In this case, the switch spring 8 should be one that elastically holds the roller retainer 7 in the engaged position (rather than the disengaged position).

[0054] Figure 7 shows an example of a drive unit 50 using the rotary transmission device M of the above embodiment. This drive unit 50 is a hybrid drive unit having an engine 53 and an electric motor 54.

[0055] The drive unit 50 includes an engine 53, a shaft 56, a bevel gear device 57 connecting the engine 53 and the shaft 56, and an electric motor 54 positioned perpendicular to the shaft 56. A rotary transmission device M and a reduction gear 58 are incorporated between the electric motor 54 and the shaft 56.

[0056] For example, as shown in Figure 7, a rotary transmission device M is positioned between an electric motor 54 and a reduction gear 58, and an engine 53, which is a prime mover with higher output than the electric motor 54, is positioned on the output side of the reduction gear 58. This can be applied to a mechanism that switches between a drive mode driven by the electric motor 54 and a drive mode driven by the engine 53. The engine 53 may be replaced with another type of prime mover with higher output than the electric motor 54. Here, the electric motor 54 is connected to the input shaft 12 of the rotary transmission device M (see Figure 1), and the reduction gear 58 is connected to the output shaft 17 of the rotary transmission device M (see Figure 1). By energizing the electromagnet 9 of the rotary transmission device M shown in Figure 1, and setting it to a state where rotation is transmitted between the inner ring 5 and the outer ring 4, the rotation of the electric motor 54 shown in Figure 7 can be transmitted to the shaft 56 via the rotary transmission device M and the reduction gear 58 (motor drive mode). On the other hand, when the shaft 56 is rotated using the power of the engine 53 shown in Figure 7, the power supply to the electromagnet 9 of the rotational transmission device M shown in Figure 1 is stopped, and the rotational transmission device M is left idle (engine-driven mode).

[0057] Incidentally, when the shaft 56 is driven by the engine 53 alone, the electric motor 54 is stopped, so the input shaft 12 (see Figure 1) of the rotation transmission device M connected to the electric motor 54 does not rotate, while the output shaft 17 (see Figure 1) of the rotation transmission device M rotates at high speed due to the rotation transmitted from the engine 53.

[0058] In other words, in this drive unit 50, the rotational transmission device M is incorporated in a location where high-speed differential rotation occurs during idling. However, as described above, even when used in a location where high-speed rotation occurs during idling, the rotational transmission device M of this embodiment can effectively prevent the separation spring 41 shown in Figure 1 from wearing down due to rotational sliding, and prevent the roller 6 from misengaging between the inner circumference of the outer ring 4 and the outer circumference of the inner ring 5. Thus, the rotational transmission device M is suitable for power transmission switching applications in mechanisms where the output side rotates at high speed and idles, such as the drive unit 50 shown in Figure 7.

[0059] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0060] 4 Outer ring 5. Inner Ring 6. Roller (engineer) 7 Roller retainer (engager retainer) 8 Switch springs 8a First switch spring 8b Second switch spring 9 Electromagnet 10 Armature 11. Operation conversion mechanism 22 pockets 23 First spring engagement part 24 Second spring engagement part 36 Rotor 41 Detachment spring 42 Spring support member M Rotational transmission device

Claims

1. Outer ring (4) and, An inner ring (5) is positioned radially inward of the outer ring (4) and is supported so as to be rotatable relative to the outer ring (4), An engaging element (6) is incorporated between the inner circumference of the outer ring (4) and the outer circumference of the inner ring (5), An engaging element retainer (7) is supported so as to be movable in the circumferential direction between an engaging position in which the engaging element (6) is engaged between the outer circumference of the inner ring (5) and the inner circumference of the outer ring (4), and an disengagement position in which the engaging element (6) is disengaged from the outer circumference of the inner ring (5) and the inner circumference of the outer ring (4), A ring-shaped electromagnet (9), An armature (10) is positioned opposite the electromagnet (9) in the axial direction so as to move in the axial direction when current is applied to the electromagnet (9), A rotational transmission device having an action conversion mechanism (11) that moves the engaging element retainer (7) circumferentially from one of the engaged position and the disengaged position to the other in accordance with the axial movement of the armature (10), The electromagnet (9) is formed to have an inner diameter larger than the outer diameter of the outer ring (4), and the electromagnet (9) is positioned radially outward of the outer ring (4) so ​​as to surround the outer circumference of the outer ring (4). The device further includes a switch spring (8) that elastically holds the engaging element retainer (7) in the disengaged position. The engaging element retainer (7) is a cylindrical member having a pocket (22) for housing the engaging element (6), The switch spring (8) consists of a first switch spring (8a) that engages with a first spring engagement portion (23) formed on one axial side of the pocket (22) of the engaging element retainer (7), and a second switch spring (8b) that engages with a second spring engagement portion (24) formed on the other axial side of the pocket (22) of the engaging element retainer (7). The rotational transmission device is characterized in that the first spring engagement portion (23) and the second spring engagement portion (24) are arranged so as to be 180° opposite to each other when viewed from the axial direction.

2. The armature (10) is further biased in the axial direction away from the electromagnet (9) by a separation spring (41), The armature (10) is prevented from rotating by the engaging element retainer (7) so as to rotate integrally with the engaging element retainer (7). The rotational transmission device according to claim 1, wherein one axial end of the separation spring (41) abuts against the armature (10), and the other axial end of the separation spring (41) is supported by a spring receiving member (42) provided to rotate integrally with the inner ring (5).

3. The present invention further comprises an annular rotor (36) fixed to the outer ring (4) so ​​as to rotate integrally with the outer ring (4), and positioned between the armature (10) and the electromagnet (9), The rotational transmission device according to claim 2, wherein the spring receiving member (42) is arranged radially inward of the rotor (36).

4. The rotational transmission device according to any one of claims 1 to 3, wherein the electromagnet (9) and the outer ring (4) are arranged on the same axial side with respect to the armature (10).

5. Outer ring (4) and, An inner ring (5) is positioned radially inward of the outer ring (4) and is supported so as to be rotatable relative to the outer ring (4), An engaging element (6) is incorporated between the inner circumference of the outer ring (4) and the outer circumference of the inner ring (5), An engaging element retainer (7) is supported so as to be movable in the circumferential direction between an engaging position in which the engaging element (6) is engaged between the outer circumference of the inner ring (5) and the inner circumference of the outer ring (4), and an disengagement position in which the engaging element (6) is disengaged from the outer circumference of the inner ring (5) and the inner circumference of the outer ring (4), A ring-shaped electromagnet (9), An armature (10) is positioned opposite the electromagnet (9) in the axial direction so as to move in the axial direction when current is applied to the electromagnet (9), A rotational transmission device having an action conversion mechanism (11) that moves the engaging element retainer (7) circumferentially from one of the engaged position and the disengaged position to the other in accordance with the axial movement of the armature (10), The electromagnet (9) is formed to have an inner diameter larger than the outer diameter of the outer ring (4), and the electromagnet (9) is positioned radially outward of the outer ring (4) so ​​as to surround the outer circumference of the outer ring (4). The armature (10) is further biased in the axial direction away from the electromagnet (9) by a separation spring (41), The armature (10) is prevented from rotating by the engaging element retainer (7) so as to rotate integrally with the engaging element retainer (7). A rotational transmission device characterized in that one axial end of the separation spring (41) abuts against the armature (10), and the other axial end of the separation spring (41) is supported by a spring receiving member (42) provided to rotate integrally with the inner ring (5).

6. The device further includes a switch spring (8) that elastically holds the engaging element retainer (7) in the disengaged position. The engaging element retainer (7) is a cylindrical member having a pocket (22) for housing the engaging element (6), The rotational transmission device according to claim 5, wherein the switch spring (8) comprises a first switch spring (8a) that engages with a first spring engagement portion (23) formed on one axial side of the pocket (22) of the engaging element retainer (7), and a second switch spring (8b) that engages with a second spring engagement portion (24) formed on the other axial side of the pocket (22) of the engaging element retainer (7).

7. The present invention further comprises an annular rotor (36) fixed to the outer ring (4) so ​​as to rotate integrally with the outer ring (4), and positioned between the armature (10) and the electromagnet (9), The rotational transmission device according to claim 5 or 6, wherein the spring receiving member (42) is arranged radially inward of the rotor (36).

8. The rotational transmission device according to claim 5 or 6, wherein the electromagnet (9) and the outer ring (4) are arranged on the same axial side with respect to the armature (10).

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