JP2008051244A - Rotation transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the number of part items in a rotation transmission device including a two-way clutch incorporated between an outer ring and a cam ring incorporated therein, and an electromagnetic clutch for controlling the engagement and disengagement thereof. <P>SOLUTION: The two-way clutch 10 is incorporated between the outer ring 3 and the cam ring 4, and the electromagnetic clutch 20 is juxtaposed thereto. The electromagnetic clutch 20 is formed of an armature 22 locked by a retainer 14 of the two-way clutch 10, a switching plate 23, a rotor 21, an electromagnet 25, and a receding spring 24, the rotor 21 is made to attract the switching plate 23 by applying a current to the electromagnet 25, and a rotor supporting rotor guide which has been conventionally needed is dispensed to thereby reduce the number of part items. A rolling bearing 32 is incorporated between the armature 22 and the switching plate 23 to stabilize frictional resistance between the opening end surface 31 of the outer ring 3 and the armature 22 to thereby improve operability in the engagement of the two-way clutch 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation transmission device that transmits and blocks rotational torque between a drive shaft and a driven shaft.

  A steer-by-wire that manipulates the steering angle of the steering gear via a steering actuator controlled by the controller according to the steering angle of the steering wheel, and transmits the steering reaction force controlled by the controller to the steering wheel via the reaction force simulator. In the system, since the steering wheel and the steering gear are not mechanically connected, if the steering actuator, the reaction force simulator, or the like breaks down, the steering may become impossible.

  In order to eliminate such inconvenience, in the steer-by-wire system described in Patent Document 1, between the first shaft that transmits the rotation of the steering wheel and the second shaft that transmits the rotational torque to the steering gear, A rotation transmission device including a two-way clutch and an electromagnetic clutch for controlling the two-way clutch is provided, and when the steering actuator, reaction force simulator, or the like breaks down, the first shaft is driven by the two-way clutch of the rotation transmission device. And the second shaft are coupled so that the steering wheel can be directly steered.

  Here, the two-way clutch forms a cylindrical surface on the inner periphery of the outer ring connected to the second shaft, and the outer periphery of the cam ring incorporated in the outer ring and connected to the first shaft is connected to the cylindrical surface. A cam surface is formed between the cam surface and the cylindrical surface, and the cage is held by the relative rotation of the cage and the cam ring. The combination is engaged with the cylindrical surface and the cam surface. Also, a switch spring is incorporated between the cam ring and the cage, and the cage is elastically held at the neutral position where the engagement element is disengaged from the cylindrical surface and the cam surface by the switch spring.

  On the other hand, the electromagnetic clutch includes a rotor disposed coaxially with the outer ring, an armature that is movable in the axial direction between the rotor and the cage and is prevented from rotating with respect to the cage, and the armature A switching plate supported so as to be movable in the axial direction between the rotor and the rotor, a separation spring that urges the switching plate in a direction away from the rotor, and opposed to the rotor. A cage that consists of an electromagnetic coil to be adsorbed, and when the energization of the electromagnetic coil is released, the switching plate is separated from the rotor by the pressing force of the separation spring and the armature is pressed against the opening end of the outer ring, and the armature is prevented from rotating. And the cam ring are engaged with each other by the relative rotation of the cam ring and the outer ring. Combining Muringu, so that transmit rotation of the first shaft to the second shaft.

JP 2005-262969 A

  By the way, in the rotation transmission device described in the above-mentioned patent document 1, since the rotor is prevented from rotating with respect to the outer ring by the rotor guide incorporated in the opening end portion of the outer ring and secured by the retaining ring. The number of points is large, and it takes time to assemble, and the cost is high. In order to reduce the number of parts, there are points to be improved.

  An object of the present invention is to provide a rotation transmission device in which a two-way clutch is incorporated between an outer ring and a cam ring incorporated therein, and the engagement and disengagement of the two-way clutch are controlled by an electromagnetic clutch. This is to reduce the number of parts.

  In order to solve the above-described problem, in the present invention, a two-way clutch for coupling and releasing the outer ring and the cam ring is incorporated between the outer ring and the cam ring incorporated therein, and the engagement of the two-way clutch and An electromagnetic clutch for controlling the disengagement is provided in the two-way clutch. The two-way clutch forms a cylindrical surface on the inner periphery of the outer ring, and both ends in the circumferential direction are narrower between the outer periphery of the cam ring and the cylindrical surface. A plurality of cam surfaces forming a wedge-shaped space are provided at equal intervals, an engagement element is incorporated between each cam surface and the cylindrical surface, and the engagement element is held by a cage incorporated between the outer ring and the cam ring, In a rotation transmission device configured to incorporate a switch spring that elastically holds a cage in a neutral position where an engagement element is disengaged from the cylindrical surface and the cam surface between the cage and the cam ring. An electromagnetic clutch, a rotor fitted on a shaft integral with the cam ring, an armature that is movable in the axial direction between the rotor and the cage, and is prevented from rotating with respect to the cage; A switching plate that is movable in the axial direction between the armature and the rotor, a separation spring that urges the switching plate in a direction away from the rotor, and a rotor plate that is disposed opposite to the rotor. An electromagnet to be adsorbed, the rotor is integrated with the cam ring shaft, and the armature is pressed against the opening end face of the outer ring by the pressing of the separating spring, and the friction resistance between the opening end face of the outer ring and the armature is Adopting a configuration that is larger than the frictional resistance between the switching plate and the switching plate Than is.

Here, as a method of making the frictional resistance between the opening end face of the outer ring and the armature larger than the frictional resistance between the armature and the switching plate, a rolling bearing is incorporated between the facing surfaces of the armature and the switching plate,
The contact between the armature and the switching plate is a rolling contact, and the contact between the outer ring opening end surface and the armature is a surface contact, and the friction coefficient μ1 between the outer ring opening end surface and the armature facing surface is the friction coefficient between the armature and the switching plate. A method of making it larger than μ2 can be adopted.

  Further, as a method for establishing the relationship of friction coefficient μ1> friction coefficient μ2, a friction material is fixed to at least one of the opening end surface of the outer ring and the facing surface of the armature, or at least one of the opening end surface of the outer ring and the facing surface of the armature. It is possible to adopt a method of roughening the surface.

  As described above, the rotor guide and the retaining ring for retaining the rotor guide described in Patent Document 1 are not required by fitting and integrating the rotor with the shaft integrally provided on the cam ring. In addition, the number of parts can be reduced, the assembly can be facilitated and the cost can be reduced, and the dimensional management of each part can be facilitated.

  Further, in a state where the armature is pressed against the opening end surface of the outer ring by pressing the separation spring, the friction resistance between the opening end surface of the outer ring and the armature is made larger than the friction resistance between the armature and the switching plate, The energization of the electromagnetic coil of the electromagnet is cut off, and when the two-way clutch is engaged by the relative rotation of the cam ring and the cage, the rotational force of the rotor that rotates together with the cam ring shaft can Can be absorbed.

  For this reason, since the frictional resistance can be stably imparted between the opening end face of the outer ring and the armature by the elastic force of the separation spring, the cage and the cam ring in which the armature is prevented from rotating can be reliably rotated relative to each other. In addition, the operability when the two-way clutch is engaged can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the housing 1 has a cylindrical shape, an end plate 2 is provided at one end, and the other end is open.

  An outer ring 3 is incorporated in the housing 1, and a cam ring 4 is incorporated in the outer ring 3. The cam ring 4 has a first shaft 5, which passes through the end plate 2 of the housing 1 and is rotatably supported by a bearing 6 incorporated in the through portion.

  The outer ring 3 has a closed end on the opening end side of the housing 1, and a second shaft 7 is provided at the closed end. The outer ring 3 is rotatably supported by a bearing 8 incorporated in the opening end of the housing 1. In addition, a bearing 9 that rotatably supports the end portion of the first shaft 5 is incorporated in the outer ring 3.

  Between the cam ring 4 and the outer ring 3, a two-way clutch 10 that couples and releases the cam ring 4 and the outer ring 3 is incorporated.

  As shown in FIGS. 1 and 4, the two-way clutch 10 is formed with a cylindrical surface 11 on the inner periphery of the outer ring 3, and both ends of the cam ring 4 in the circumferential direction are narrow between the cylindrical surface 11 and the outer periphery 3. A flat cam surface 12 forming a wedge-shaped space is continuously provided in the circumferential direction, and a roller 13 as an engaging member is incorporated between each cam surface 12 and the cylindrical surface 11, and the roller 13 is formed in a cage 14. Is held by the pocket 15.

  In addition, a cylindrical portion 16 is formed on the end surface of the cam ring 4 on the outer ring opening side, a switch spring 17 partially cut away is incorporated into the cylindrical portion 16, and a pair of pressings formed at both ends of the switch spring 17. A pair of side surfaces, in which the piece 17 a is fitted into a notch 19 provided at the end of the retainer 14 from a notch 18 formed in the cylindrical portion 16, are opposed to each other in the circumferential direction of the notch 18 and the notch 19. The retainer 14 is elastically held at a position where the roller 13 is disengaged from the cylindrical surface 11 and the cam surface 12 by pressing in opposite directions.

  As shown in FIG. 1, on the first shaft 5 provided integrally with the cam ring 4, an electromagnetic clutch that controls the engagement and disengagement of the two-way clutch 10 along with the two-way clutch 10 is provided. 20 is provided.

  The electromagnetic clutch 20 includes a rotor 21 made of a magnetic material disposed coaxially with the first shaft 5, an armature 22 disposed between the rotor 21 and the opening end surface of the outer ring 3, and between the armature 22 and the rotor 21. The switching plate 23 is incorporated, a separation spring 24 that urges the switching plate 23 in a direction away from the rotor 21, and an electromagnet 25 that is opposed to the rotor 21 in the axial direction.

  As shown in FIG. 2, a plurality of arc-shaped slits S are formed on the rotor 21 at equal intervals on the same circle. Further, the rotor 21 is formed with cylindrical portions 21 a and 21 b facing in the same direction on the outer periphery and the inner periphery, and the inner cylindrical portion 21 b is fitted and integrated with the first shaft 5.

  Here, the first shaft 5 is formed with a large diameter portion 5a on the cam ring 4 side, and a step portion 26 is provided on the outer periphery. The rotor 21 is positioned in the axial direction by contact with the step portion 26, and the outer ring A constant interval is formed between the three open end faces.

  An engagement groove 27 is formed on the outer periphery of the end of the outer cylindrical portion 21 a of the rotor 21, and a separation spring 24 is assembled between the facing surfaces of the retaining ring 28 attached to the engagement groove 27 and the switching plate 23.

  The armature 22 is fitted to the outer periphery of the cylindrical portion 16 formed on the end face of the cam ring 4 and is supported so as to be movable in the axial direction. An engagement hole 29 is formed in the armature 22, and an engagement piece 30 formed at the opening end of the retainer 14 is engaged with the engagement hole 29, and the armature 22 is engaged with the retainer 14 by the engagement. On the other hand, it is prevented from rotating and is movable in the axial direction.

  The outer diameter of the armature 22 is substantially the same as the outer diameter of the outer ring 3, and the opening end surface 31 of the outer ring 3 is a contact surface with respect to the armature 22, and the opening end surface 31 allows the armature 22 to be separated from the rotor 21. Limited.

  The switching plate 23 is fitted to the large diameter portion 5a of the first shaft 5 and is movable in the axial direction. A rolling bearing 32 is incorporated between the opposing surfaces of the switching plate 23 and the armature 22 so that the contact between the switching plate 23 and the armature 22 is a rolling contact.

  On the other hand, in a state where the armature 22 is pressed against the opening end surface 31 of the outer ring 3 by the pressing of the separation spring 24, the contact between the armature 22 and the opening end surface 31 is a surface contact, and the frictional resistance of the contact portion is the same as that of the switching plate 23. It is larger than the frictional resistance between the armatures 22.

  The electromagnet 25 includes an electromagnetic coil 25 a and a core 25 b that supports the electromagnetic coil 25 a, and the core 25 b is integrally supported by the end plate 2 of the housing 1.

  The rotation transmission device shown in the embodiment has the above-described structure, and when the rotation transmission device is employed in the steer-by-wire system disclosed in Patent Document 1, the rotation of the steering wheel is transmitted to the first shaft 5. In addition, the rotation of the second shaft 7 is transmitted to the steering gear. During normal operation, the electromagnetic coil 25a of the electromagnet 25 is energized, and when the steering becomes impossible due to a failure in the electric system, the energization of the electromagnetic coil 25a is cut off.

  FIG. 2 shows an energization state of the electromagnet 25 to the electromagnetic coil 25a, and as a result of the energization, a magnetic flux flows through the core 25b, the rotor 21 and the switching plate 23 as shown by a chain line a in FIG. And the connection of the armature 22 to the outer ring 3 is released.

  Therefore, when the cam ring 4 rotates together with the first shaft 5 by steering the steering wheel, the rotation is transmitted to the holder 14 via the switch spring 17, and the holder 14 rotates together with the cam ring 4, and FIG. ), The roller 13 rotates while being held in a neutral position where the engagement with the cylindrical surface 11 and the cam surface 12 is released. For this reason, the rotation of the cam ring 4 that rotates together with the first shaft 5 is not transmitted to the outer ring 3, and the first shaft 5 and the cam ring 4 rotate freely.

  When the energization to the electromagnetic coil 25a is released, the switching plate 23 moves away from the rotor 21 due to the restoring elasticity of the separation spring 24, and as a result, the armature 22 opens the end face of the outer ring 3 as shown in FIG. It is pressed against 31 and coupled to the outer ring 3.

  For this reason, when the cam ring 4 rotates together with the first shaft 5 by steering the steering wheel, the cam ring 4 and the cage 14 rotate relative to each other. As a result, the roller 13 is cylindrical as shown in FIG. The two-way clutch 10 is engaged with the surface 11 and the cam surface 12 to connect the cam ring 4 and the outer ring 3.

  For this reason, the steering gear can be manually operated by the steering wheel.

  When the cage 14 and the cam ring 4 are rotated relative to each other, the switch spring 17 is elastically deformed. Therefore, after the electric system failure is repaired, when the electromagnetic coil 25a is energized and the switching plate 23 is attracted to the rotor 21, the retainer 14 is restored by the restoring elasticity of the switch spring 17, and FIG. As shown, the roller 13 is returned to the neutral position where the engagement with the cylindrical surface 11 and the cam surface 12 is released.

  As shown in the embodiment, by fitting and integrating the rotor 21 to the first shaft 5 provided integrally with the cam ring 4, the rotor guide described in Patent Document 1 and the rotor guide are removed. A retaining ring for stopping can be dispensed with. For this reason, compared with the rotation transmission device described in Patent Document 1, the number of parts is reduced, and the assembly can be facilitated and the cost can be reduced.

  Further, a rolling bearing 32 is incorporated between the facing surfaces of the armature 22 and the switching plate 23 so that the frictional resistance between the armature 22 and the switching plate 23 is determined by the frictional resistance between the opening end surface 31 of the outer ring 3 and the armature 22. By making it smaller, the energization of the electromagnet 25 to the electromagnetic coil 25a is cut off, and the rotation of the rotor 21 that rotates together with the first shaft 5 is engaged when the two-way clutch 10 is engaged by the relative rotation of the cam ring 4 and the retainer 14. The force can be absorbed by the relative rotation of the armature 22 and the switching plate 23.

  For this reason, a frictional resistance can be stably provided between the opening end surface 31 of the outer ring 3 and the armature 22 by the elastic force of the separation spring 24. Therefore, the cage 14 and the cam ring 4 can be reliably rotated relative to each other, and the operability when the two-way clutch 10 is engaged can be improved.

  FIG. 6 shows another example of the rotation transmission device according to the present invention. In this example, the rolling bearing 32 shown in FIG. 2 is omitted, and the friction material 33 is bonded to each of the opening end surface 31 of the outer ring 3 and the facing surface of the armature 22, which is different from the rotary bearing device shown in FIG. 2. ing. For this reason, the same components as those shown in FIG.

  As shown in FIG. 6, by attaching a friction material 33 to each of the opening end surface 31 of the outer ring 3 and the facing surface of the armature 22, the friction resistance between the opening end surface 31 of the outer ring 3 and the armature 22 is reduced. The friction resistance between the switching plates 23 can be made larger.

  For this reason, most of the rotational force applied to the switching plate 23 from the rotor 21 rotating together with the first shaft 5 can be absorbed by slippage (relative rotation) at the contact portion between the switching plate 23 and the armature 22.

  For this reason, the elastic force of the separation spring 24 can stably provide a frictional resistance between the opening end surface 31 of the outer ring 3 and the armature 22, and the two-way clutch 10 of the two-way clutch 10 is rotated by the relative rotation of the cam ring 4 and the cage 14. The operability at the time of engagement can be improved.

  In FIG. 6, the friction material 33 is bonded to each of the opening end surface 31 of the outer ring 3 and the facing surface of the armature 22, but one friction material 33 may be omitted. Further, instead of the friction material 33, a rough surface is formed on at least one of the facing surfaces of the opening end surface 31 of the outer ring 3 and the armature 22, and the friction resistance between the opening end surface 31 of the outer ring 3 and the armature 22 is reduced. And the friction resistance between the switching plates 23 may be larger.

Longitudinal front view showing an embodiment of a rotation transmission device according to the present invention Sectional drawing which expands and shows a part of two-way clutch and electromagnetic clutch part shown in FIG. Sectional drawing which shows the interruption | blocking state of electricity supply with respect to an electromagnetic coil Sectional view along line IV-IV in FIG. (I) is a sectional view showing the disengaged state of the two-way clutch, (II) is a sectional view showing the engaged state of the two-way clutch Sectional drawing which shows other embodiment of the rotation transmission apparatus which concerns on this invention

Explanation of symbols

3 Outer ring 4 Cam ring 5 First shaft
10 Two-way clutch 11 Cylindrical surface 12 Cam surface 13 Roller (engagement element)
14 Cage 17 Switch Spring 20 Electromagnetic Clutch 21 Rotor 22 Armature 23 Switching Plate 24 Separation Spring 25 Electromagnet 25a Electromagnetic Coil 31 Open End Face 32 Rolling Bearing 33 Friction Material

Claims (4)

A two-way clutch for connecting and releasing the outer ring and the cam ring is incorporated between the outer ring and the cam ring incorporated in the inner ring, and the electromagnetic clutch for controlling the engagement and release of the two-way clutch is a two-way clutch. In addition, the two-way clutch forms a cylindrical surface on the inner periphery of the outer ring, and a plurality of cam surfaces that form a narrow wedge-shaped space at both ends in the circumferential direction between the cylindrical surface and the outer periphery of the cam ring, etc. An engagement element is provided between each cam surface and the cylindrical surface, and the engagement element is held by a cage incorporated between the outer ring and the cam ring, and the engagement element is a cylinder between the cage and the cam ring. In the rotation transmission device configured to incorporate a switch spring that elastically holds the cage in a neutral position disengaged from the surface and the cam surface,
A rotor fitted to a shaft integral with the cam ring, an armature that is movable in the axial direction between the rotor and the cage, and is prevented from rotating with respect to the cage; A switching plate that is movable in the axial direction between the armature and the rotor, a separation spring that urges the switching plate in a direction away from the rotor, and a rotor that is disposed opposite to the rotor. In the state where the rotor is integrated with the cam ring shaft and the armature is pressed against the opening end surface of the outer ring by the pressing of the separating spring, the friction resistance between the opening end surface of the outer ring and the armature is reduced. It is characterized by a larger frictional resistance between the armature and the switching plate Rotation transmitting device for. Incorporating a rolling bearing between the facing surfaces of the armature and the switching plate,
The rotation transmission device according to claim 1, wherein the contact between the armature and the switching plate is rolling contact, and the contact between the opening end face of the outer ring and the armature is surface contact.   2. The rotation transmission device according to claim 1, wherein μ1> μ2 when a friction coefficient between the opening end face of the outer ring and the facing surface of the armature is μ1 and a friction coefficient between the armature and the switching plate is μ2.   The rotation transmission device according to claim 3, wherein a friction material is fixed to at least one of the opening end surface of the outer ring and the facing surface of the armature.

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