JP2008032036A - Rotation transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a two-way clutch from being erroneously engaged by reducing a gap in a rotation transmission device in the rotating direction. <P>SOLUTION: A two-way clutch 10 is assembled between an outer ring 1 and a cam ring 4. An electromagnetic clutch 30 for controlling the engagement and disengagement of the two-way clutch is installed in the rotation transmission device. In the two-way clutch 10, rollers 13 are assembled between a cylindrical surface 11 formed on the inner periphery of the outer ring 1 and cam surfaces 12 formed on the outer periphery of the cam ring 4, and the rollers 13 are held by a retainer 14. A pair of rollers 13 holding the corner 12a of the adjacent cam surfaces 12 are assembled in the pockets formed in the retainer 14, biased toward the peripheral ends of the pockets by an elastic member, and disposed at a standby position where the rollers 13 can be immediately engaged with the cylindrical surface 11 and the cam surface 12 in the state that the rollers 13 are brought into contact with the peripheral end to reduce a gap in the rotation transmission device in the rotating direction. Also, the rollers 13 are prevented from being erroneously engaged while the cam ring 4 is freely rotating. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  In an FR-based four-wheel drive vehicle, a two-way clutch is incorporated between the outer ring and the cam ring built into the outer ring as a rotation transmission device that transmits and blocks driving force to the front wheel as an auxiliary drive wheel. The electromagnetic clutch attached to the clutch controls the engagement and disengagement of the two-way clutch, the outer ring and the cam ring are coupled by the engagement of the two-way clutch, and torque is transmitted between the outer ring and the cam ring. What has been known is conventionally known.

  Here, the two-way clutch forms a cylindrical surface on the inner periphery of the outer ring, and a cam surface is formed on the outer periphery of the cam ring. A roller is incorporated between the cam surface and the cylindrical surface, and the roller is engaged with the cylindrical surface and the cam surface by the relative rotation of the retainer that holds the roller and the inner ring. Further, a switch spring is incorporated between the cam ring and the cage, and the cage is elastically held by the switch spring at a neutral position where the roller is disengaged from the cylindrical surface and the cam surface.

  On the other hand, the electromagnetic clutch faces the rotor connected to the outer ring to the armature that is supported by the cage and is movably supported in the axial direction, and the electromagnet is opposed to the rotor. The armature is attracted to the rotor, and the roller is engaged with the cylindrical surface and the cam surface by the relative rotation of the armature and the cam ring coupled to the outer ring.

  In the rotation transmission device, the two-way clutch is engaged by energizing the electromagnetic coil of the electromagnet, and it is necessary to keep a relatively large current flowing through the electromagnetic coil in order to maintain the engaged state of the two-way clutch. There is a problem with the economy. If the electromagnetic coil is disconnected, the two-way clutch cannot be engaged, which may cause a safety problem.

In order to eliminate such an inconvenience, the applicant of the present invention disclosed in Patent Document 1 that a slit is formed in the rotor, a permanent magnet is incorporated in the slit, and the armature is attracted by the permanent magnet after the two-way clutch is engaged. And a rotation transmission device that minimizes energization to the electromagnetic coil.
JP 2004-190730 A

  By the way, in the rotation transmission device described in Patent Document 1, since a plurality of rollers are arranged at equiangular positions, all the rollers are simultaneously engaged with the cylindrical surface and the cam surface by the relative rotation of the cam ring and the cage. Will match.

  For this reason, the moving angle of the roller is large from the engagement position of the roller when the cam ring and the cage are rotated in the clockwise direction to the engagement position of the roller when the cam ring and the cage are rotated in the counterclockwise direction. The movement angle becomes the backlash in the rotational direction of the two-way clutch, and the rotational backlash generates noise when the roller is engaged, or the roller impacts into the narrow part of the wedge-shaped space and deforms or breaks. There is a possibility to cause.

  Here, by reducing the inner diameter of the cylindrical inner surface of the outer ring or increasing the outer diameter of the roller, the backlash in the rotational direction can be reduced. In this case, the roller held in the neutral position and the cylindrical inner surface The radial gap formed between them becomes smaller, and the drag torque is applied to the roller by the viscous resistance of the lubricating oil interposed in the radial gap, and the cam ring and the cage rotate relative to each other by the drag torque, so that the two-way clutch There is a risk of misengaging.

  An object of the present invention is to reduce the backlash in the rotational direction and to prevent misengagement of the two-way clutch in the above-described rotation transmission device in which a permanent magnet is incorporated in the slit of the rotor.

  In order to solve the above-mentioned problems, in the present invention, a cylindrical surface is formed on the inner periphery of the outer ring, and a wedge having narrow ends at the circumferential direction between the outer periphery of the cam ring incorporated inside the outer ring and the cylindrical surface. A plurality of cam surfaces forming a shape space are provided at equal intervals, a roller is incorporated between each cam surface and the cylindrical surface, and the roller is accommodated in a pocket of a cage assembled between the outer ring and the cam ring, and held. The elastic force of the switch spring is applied to the retainer, the retainer is elastically held at the disengagement position where the roller is disengaged from the cylindrical surface and the cam surface. An elastic part that faces the rotor against the armature that is movably supported, opposes the electromagnet that moves the armature in the axial direction by energization or de-energization, and urges the armature in a direction away from the rotor In the rotation transmission device in which a permanent magnet is incorporated in a slit formed in the rotor and the armature is attracted toward the rotor, the pocket formed in the cage is connected between adjacent cam surfaces. The pair of rollers on both sides sandwiching the corner are sized to be accommodated, and the roller is in a standby position where the roller contacts the circumferential end of the pocket between the adjacent cam surfaces from the center of the circumferential width of the cam surface. The circumferential length is arranged at a position offset toward the corner side, and a configuration is adopted in which an elastic member for biasing the pair of rollers toward the standby position is incorporated in the pocket.

  As described above, a pocket having a size to accommodate a pair of rollers on both sides sandwiching a corner between the cam surfaces adjacent to the cage is formed, and the circumferential length of the pocket is set to the roller at the circumferential end. When the cam ring and the cage rotate relative to each other in the clockwise direction, the length of the roller is arranged so as to be offset from the center of the circumferential width of the cam surface to the corner between the adjacent cam surfaces. When one of the pair of rollers incorporated in the pocket immediately engages the cylindrical surface and the cam surface, and the cam ring and the cage rotate relative to each other in the counterclockwise direction, the other roller immediately engages the cylindrical surface and the cam surface. As a result, a rotation transmission device with small rotation direction backlash and excellent durability can be obtained.

  In addition, by incorporating an elastic member in the pocket and biasing the pair of rollers toward the circumferential end of the pocket, the pair of rollers can be securely held at the standby position, and misengagement of the rollers can be prevented. Can be prevented.

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

  A cam ring 4 is fitted to a portion of the input shaft 2 located in the outer ring 1, and the cam ring 4 is prevented from rotating around the input shaft 2 by a serration 5 and is positioned in the axial direction by a retaining ring 6.

  A two-way clutch 10 is incorporated between the outer ring 1 and the cam ring 4. As shown in FIGS. 1 and 5, the two-way clutch 10 has a cylindrical surface 11 formed on the inner periphery of the outer ring 1, and the outer periphery of the cam ring 4 is narrow at both ends in the circumferential direction with the cylindrical surface 11. A flat cam surface 12 forming a wedge-shaped space is provided continuously in the circumferential direction, and a roller 13 is incorporated between each cam surface 12 and the cylindrical surface 11, and the roller 13 is held by a cage 14.

  Here, the cage 14 is formed with a pocket 15 having a size to accommodate a pair of rollers 13 on both sides sandwiching the corner 12a of the adjacent cam surface 12, and the circumferential length of the pocket 15 is the circumferential direction. One roller 13 is in contact with one end of the roller, and the other roller 13 is in contact with the other end in the circumferential direction. The pair of rollers 13 are arranged on the corner 12a side from the center of the circumferential width of the cam surface 12. An elastic member 16 that urges each roller 13 toward the circumferential end of the pocket 15 by pressing the pair of rollers 13 away from each other is incorporated in the pocket 15.

  As shown in FIGS. 2 and 4, a spring accommodating recess 17 is formed at one end of the cam ring 4, and a switch spring 18 is incorporated in the spring accommodating recess 17. The switch spring 18 has a C shape, and a pair of pressing pieces 18 a provided outward from both ends thereof are provided with a notch 19 formed in the peripheral wall of the spring accommodating recess 17 and a notch provided at the end of the retainer 14. The side surfaces of the notches 19 and 20 that are inserted in the circumferential direction of the notches 19 and 20 are opposed to each other in opposite directions, and the retainers 14 are elastically held in such a state that the rollers 13 are held at the standby positions. is doing.

  The switch spring 18 is prevented from coming out of the spring accommodating recess 17 by the connecting plate 21 fitted to the small diameter cylindrical portion 4 a at the end of the cam ring 4. The connecting plate 21 is positioned in the axial direction by a retaining ring 22, and an L-shaped engagement piece 23 is provided on the outer periphery. The engagement piece 23 engages with the notch 20 provided at the end of the retainer 14, and the connecting plate 21 is prevented from rotating around the retainer 14 by the engagement.

  As shown in FIG. 1, an electromagnetic clutch 30 that controls the engagement and disengagement of the two-way clutch 10 is provided between the outer ring 1 and the cage 14 along with the two-way clutch 10. .

  The electromagnetic clutch 30 includes an armature 31 disposed to face the end face of the cage 14, a rotor 32 that faces the armature 31 in the axial direction, and an electromagnet 33 that faces the rotor 32 in the axial direction.

  As shown in FIG. 2, the armature 31 is slidably fitted to a small diameter cylindrical portion 4 a provided at the end of the cam ring 4. An engagement hole 34 is formed in the armature 31, and the engagement piece 23 on the outer periphery of the connecting plate 21 is engaged with the engagement hole 34, and the armature 31 is prevented from rotating with respect to the retainer 14 by the engagement. And is movable in the axial direction.

  The rotor 32 is press-fitted into the end portion of a rotor guide 36 made of a non-magnetic material connected to the opening end portion of the outer ring 1 and is prevented from rotating around the rotor guide 36. A plurality of arc-shaped slits 37 are formed in the rotor 32 at intervals in the circumferential direction, and a permanent magnet 38 is incorporated in each slit 37.

  An elastic member 39 that urges the armature 31 in a direction away from the rotor 32 is incorporated between the facing end surfaces of the armature 31 and the connecting plate 21.

  The electromagnet 33 includes an electromagnetic coil 33a and a core 33b that supports the electromagnetic coil 33a. When the electromagnetic coil 33a is energized, a magnetic flux flows through the core 33b, the rotor 32, and the armature 31, and an attractive force is applied to the armature 31. It has come to be.

  The rotation transmission device shown in the embodiment has the above-described structure, and the permanent magnet 38 incorporated in the slit 37 has a lower attractive force than the elastic force of the elastic member 39 when the armature 31 is separated from the rotor 32. In addition, the attractive force when the armature 31 is attracted to the rotor 32 may be stronger than the elastic force of the elastic member 39 (for convenience of explanation, the permanent magnet is referred to as a first permanent magnet), or the armature The attraction force in a state where 31 is separated from the rotor 32 may be stronger than the elastic force of the elastic member 39 (for convenience of explanation, the permanent magnet is referred to as a second permanent magnet).

  In the embodiment, the first permanent magnet 38 is employed as the permanent magnet. In this case, as shown in FIG. 2, the magnetic flux 40 generated from the first permanent magnet 38 flows between the rotor 32 and the armature 31 and an attractive force is applied to the armature 31, but the armature 31 is attracted to the rotor 32. Instead, an air gap is formed between the rotor 32 and the rotor 32.

  In the state shown in FIG. 2, the two-way clutch 10 is disengaged, and even if the cam ring 4 rotates together with the input shaft 2, the rotation is not transmitted to the outer ring 1 and the cam ring 4 rotates freely.

  When the electromagnetic coil 33a of the electromagnet 33 is energized in the rotating state of the cam ring 4, magnetic flux flows between the core 33b, the rotor 32, and the armature 31. At this time, as shown in FIG. 3, the flow of the magnetic flux generated by the electromagnetic coil 33a is in the same direction as the magnetic flux 40 generated by the permanent magnet 38, and the armature 31 is transferred to the rotor 32 by the magnetic flux generated by the electromagnetic coil 33a. Adsorbed.

  As the armature 31 is attracted, the frictional resistance acting on the attracting surface becomes the rotational resistance of the cage 14, so that the cam ring 4 and the cage 14 rotate relative to each other, and the relative rotation causes the roller 13 to move between the cylindrical surface 11 and the cam surface. 12 is engaged.

  At this time, each of the pair of rollers 13 incorporated in the pocket 15 of the retainer 14 is held at a standby position offset from the center of the circumferential width of the cam surface 12 toward the corner 12a. When 4 rotates relative to the cage 14 in the counterclockwise direction indicated by the arrow in FIG. 6, the left roller 13 shown in FIG. 6 immediately engages the cylindrical surface 11 and the cam surface 12, and the two-way clutch 10 The engaged state is established, and the rotation of the cam ring 4 is transmitted to the outer ring 1.

  When the cam ring 4 rotates in the clockwise direction indicated by the arrow in FIG. 7 with respect to the retainer 14, the right roller 13 shown in FIG. 7 immediately engages the cylindrical surface 11 and the cam surface 12, and the two-way clutch. 10 is in an engaged state, and the rotation of the cam ring 4 is transmitted to the outer ring 1.

  As described above, the pair of rollers 13 incorporated in the pocket 15 is held at the standby position where the cylindrical surface 11 and the cam surface 12 can be immediately engaged. One of the pair of rollers 13 is immediately engaged with the cylindrical surface 11 and the cam surface 12 in accordance with the rotation direction.

  For this reason, there is very little play in the rotational direction, and there is no occurrence of engagement shock or abnormal noise during engagement.

  Here, in the attracted state of the armature 31, the gap between the armature 31 and the permanent magnet 38 becomes small, and the attractive force of the permanent magnet 38 becomes stronger than the pressing force of the elastic member 39. Even so, the armature 31 is held in the attracted state. For this reason, it consumes less electric energy and is extremely economical.

  When the two-way clutch 10 is disengaged, the energization of the electromagnetic coil 33a causes the armature 31 to generate a magnetic flux in a direction opposite to the magnetic flux generated by the permanent magnet 38, thereby weakening the attractive force applied to the armature 31. The armature 31 is separated from the rotor 32 by the pressing force of the member 39.

  As a result, the retainer 14 rotates due to the restoring elasticity of the switch spring 18, and the pair of rollers 13 assembled in the pocket 15 is returned to the standby position, and the rotation transmission from the cam ring 4 to the outer ring 1 is interrupted, and the cam ring 4 rotates freely.

  Further, the armature 31 is moved in the direction away from the rotor 32 by the pressing of the elastic member 39 to be in the state shown in FIG.

  If the pair of rollers 13 is simply assembled in the pocket 15 in a state where the cam ring 4 rotates freely, the rollers 13 may be displaced to the engagement position and misengaged. 13 is pressed against the circumferential end of the pocket 15 by the elastic member 16 and is held at the standby position, so that it is not displaced to the engagement position and is not misengaged.

  Here, when the second permanent magnet 38 is employed as the permanent magnet, the armature 31 is held in the attracted state by the attractive force of the permanent magnet 38, so that when the cam ring 4 rotates, the two-way clutch 10 is immediately engaged. In this state, rotation is transmitted from the cam ring 4 to the outer ring 1.

  When releasing the engagement of the two-way clutch 10, the energization of the electromagnetic coil 33 a causes the armature 31 to generate a magnetic flux opposite to the magnetic flux generated by the permanent magnet 38, thereby weakening the attractive force applied to the armature 31. The armature 31 is separated from the rotor 32 by the pressing force of the elastic member 39.

Longitudinal front view showing an embodiment of a rotation transmission device according to the present invention Sectional drawing which expands and shows the electromagnetic clutch part of FIG. Sectional drawing which shows the engagement state of the electromagnetic clutch of FIG. Sectional view along line IV-IV in FIG. Sectional view along line VV in FIG. Sectional drawing which shows the engagement state of a two-way clutch Sectional drawing which shows the engagement state of a two-way clutch

Explanation of symbols

1 outer ring 4 cam ring 11 cylindrical surface 12 cam surface 12a corner 13 roller 14 cage 15 pocket 16 elastic member 18 switch spring 31 armature 32 rotor 33 electromagnet 37 slit 38 permanent magnet 39 elastic member

Claims (1)

A cylindrical surface is formed on the inner periphery of the outer ring, and a plurality of cam surfaces are formed at equal intervals on the outer periphery of the cam ring incorporated on the inner side of the outer ring. A roller is installed between each cam surface and the cylindrical surface, the roller is accommodated in a pocket of a cage assembled between the outer ring and the cam ring, and the roller is loaded with the elastic force of the switch spring on the cage. The retainer is elastically held at the disengagement position where the engagement with the cylindrical surface and the cam surface is disengaged, and the rotor is opposed to the armature that is supported by the retainer and movably in the axial direction. Then, an electromagnet that moves the armature in the axial direction by energizing or shutting off the energization is opposed to the rotor, and an elastic member that biases the armature in a direction away from the rotor is provided, and a permanent member is provided in the slit formed in the rotor. In the rotation transmitting device designed to suction toward the armature to the rotor incorporates a magnet,
The pocket formed in the cage is sized to accommodate a pair of rollers on both sides sandwiching a corner between adjacent cam surfaces, and the roller at a standby position where the roller contacts the circumferential end of the pocket. Is a circumferential length arranged at a position offset from the center of the circumferential width of the cam surface toward the corner between the adjacent cam surfaces, and an elastic member for urging the pair of rollers toward the standby position in the pocket. A rotation transmission device characterized by being incorporated.

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