JP2009144867A - Rotation transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotation transmitting device capable of reducing looseness in the rotational direction of a connecting part between a torque transmission shaft and a cam ring. <P>SOLUTION: The torque transmission shaft 4 is fitted inside the cam ring 2 incorporated inside an outer ring 1, and rotation is relatively prevented by joining its torque transmission shaft 4 and the cam ring 2 by a spline 5. A roller 23 and a retainer 24 for holding its roller 23 are incorporated between the inner periphery of the outer ring 1 and the outer periphery of the cam ring 2, and rotational torque is transmitted between mutual ones of the outer ring 1 and the cam ring 2 by engaging the roller 23 with a cylindrical surface 21 of the inner periphery of the outer ring 1 and a cam surface 22 of the outer periphery of the cam ring 2 by relative rotation of its retainer 24 and the cam ring 2. An angle of torsion θ is arranged in at least one of a spline tooth 5a formed on the outer periphery of the torque transmission shaft 4 and a spline groove 5b formed on the inner periphery of the cam ring 2, and the looseness in the rotational direction of the connecting part between the torque transmission shaft 4 and the cam ring 2 is reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In a FR-based four-wheel drive vehicle, a two-way clutch is incorporated between an outer ring and a cam ring incorporated inside the outer ring as a rotation transmission device that transmits and interrupts driving force to a front wheel as an auxiliary drive wheel. Engagement and disengagement of the two-way clutch are controlled by an electromagnetic clutch attached to the directional clutch, and 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. Such an arrangement is conventionally known (see Patent Document 1).

  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 cage that holds the roller and the cam 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, and the electromagnet is energized. By shutting off, the armature is attracted to or released from the rotor, and in this attracted state, the roller is engaged with the cylindrical surface and the cam surface by the relative rotation of the armature coupled to the outer ring and the cam ring. .
JP 2004-190730 A

By the way, in the rotation transmission device described in Patent Document 1, spline grooves extending in the axial direction are formed at equal intervals in the circumferential direction on the inner periphery of the cam ring, and formed on the outer periphery of the end portion of the torque transmission shaft as the input shaft. The spline teeth are fitted into the spline grooves and the cam ring is attached to the torque transmission shaft. However, since the spline grooves and spline teeth are straight and parallel to the shaft center, the torque transmission shaft There is a problem that backlash in the rotational direction tends to occur at the connecting portion between the cam ring and the spline teeth collide with the side surface of the spline groove when the rotational direction of the torque transmission shaft is switched, resulting in abnormal noise.

  The subject of this invention is providing the rotation transmission apparatus which enabled it to reduce the play of the rotation direction of the connection part of a torque transmission shaft and a cam ring.

  In order to solve the above-described problem, in the present invention, a torque transmission shaft is fitted inside a cam ring incorporated inside the outer ring, and the torque transmission shaft and the cam ring are relatively prevented from rotating as a combination of splines, An engagement element and a retainer for holding the engagement element are incorporated between the inner periphery of the outer ring and the outer periphery of the cam ring, and the engagement element is engaged with the inner periphery of the outer ring and the outer periphery of the cam ring by relative rotation of the retainer and the cam ring. In the rotation transmission device configured to transmit the rotational torque between the outer ring and the cam ring, at least one of the spline teeth formed on the outer periphery of the torque transmission shaft and the spline groove formed on the inner periphery of the cam ring. A configuration with a twist angle was adopted.

  Here, the width dimension of the spline teeth is made smaller than the width dimension of the spline groove, one of the spline teeth and the spline groove is formed in a straight shape parallel to the axis, and the spline teeth are press-fitted into the spline groove on the other side. When the twist angle is applied, the initial fit of the spline teeth to the spline groove can be a fit of the clearance fit, so that the cam ring can be easily press-fitted into the torque transmission shaft, and the spline groove can be inserted into the spline groove. When the teeth are inserted, one side surface of the front end portion in the insertion direction of the spline teeth and the other side surface of the rear end portion are in pressure contact with both side surfaces of the spline groove, so that a connection state free from backlash in the rotation direction can be obtained.

  Further, by providing a retaining means between the fitting surfaces of the cam ring and the torque transmission shaft, it is possible to prevent the cam ring and the torque transmission shaft from separating in the axial direction due to vibration or the like.

  As the retaining means, an engagement groove extending in the circumferential direction is formed on one of the fitting surfaces, and a ring receiving groove extending in the circumferential direction is provided on the other, and elastic in the radial direction straddling the ring receiving groove and the engaging groove. By installing a deformable retaining ring and adopting a structure in which the depth of the ring receiving groove is set to a depth capable of accommodating the entire retaining ring elastically deformed, a single retaining ring can be used. With this configuration, the cam ring and the torque transmission shaft can be positioned in the axial direction.

  When positioning in the axial direction using the retaining ring, the ring receiving groove is formed on the inner periphery of the cam ring, the engaging groove is formed on the outer periphery of the torque transmission shaft, and the outer periphery of the shaft end in the insertion direction of the torque transmission shaft with respect to the cam ring When the torque transmission shaft is inserted into the inner periphery of the cam ring with the retaining ring incorporated in the ring receiving groove, the retaining ring is expanded in diameter by the tapered surface. When the torque transmission shaft is inserted to a position where the engagement groove faces the retaining ring, the retaining ring is reduced in diameter by its own restoring elasticity and engaged with the engagement groove. A retaining ring can be easily attached to the straddling position.

  Further, by adopting a retaining ring made of a wire having a circular cross section, the retaining ring can be easily expanded in diameter by the tapered surface.

  As described above, in the rotation transmission device according to the present invention, by providing a twist angle in at least one of the spline teeth formed on the outer periphery of the torque transmission shaft and the spline groove formed on the inner periphery of the cam ring, It is possible to reduce the play in the rotational direction at the fitting portion between the transmission shaft and the cam ring.

  Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a cam ring 2 is incorporated inside the outer ring 1, and the outer ring 1 and the cam ring 2 are relatively rotatably supported on the outer side of a small-diameter cylindrical portion 2 a provided at one end of the cam ring 2. A bearing 3 is incorporated.

  An end portion of the torque transmission shaft 4 is fitted into the center hole formed in the cam ring 2, and the cam ring 2 and the torque transmission shaft 4 are relatively prevented from rotating by a spline 5 provided in the fitting portion. .

  As shown in FIGS. 4 and 5, the spline 5 includes spline teeth 5 a formed at equal intervals on the outer periphery of the shaft end portion of the torque transmission shaft 4 and spline grooves formed at equal intervals on the inner periphery of the cam ring 2. The spline teeth 5a are provided with a twist angle θ with respect to the shaft center.

  As shown in FIGS. 1 and 6, a retaining means 10 for positioning the cam ring 2 and the torque transmission shaft 4 in the axial direction and retaining them is provided between the fitting portions of the cam ring 2 and the torque transmission shaft 4. It has been.

  The retaining means 10 forms an engaging groove 11 extending in the circumferential direction on the inner periphery of the cam ring 2, and a ring receiving groove 12 is provided on the outer periphery of the torque transmission shaft 4. A retaining ring 13 that is elastically deformable in the radial direction is attached so as to straddle.

  Here, the retaining ring 13 is made of a wire having a circular cross section. On the other hand, the groove depth of the engaging groove 11 is smaller than the outer diameter of the wire. The groove depth of the ring receiving groove 12 is set to a depth that can accommodate the entire retaining ring 13 having a reduced diameter. When attaching the retaining ring 13, the retaining ring 13 is fitted to the outer periphery of the torque transmission shaft 4, the retaining ring 13 is reduced in diameter at the position of the ring accommodating groove 12, and the whole is accommodated in the ring accommodating groove 12. In this state, the torque transmission shaft 4 is inserted into the cam ring 2, and the retaining ring 13 is expanded by its own restoring elasticity at the position of the engagement groove 11 to engage both the engagement groove 11 and the ring receiving groove 12. I will let you.

  As shown in FIGS. 1 and 2 (I), a two-way clutch 20 is incorporated between the cam ring 2 and the outer ring 1. The two-way clutch 20 forms a cylindrical surface 21 on the inner periphery of the outer ring 1, and a flat cam surface on the outer periphery of the cam ring 2 that forms a narrow wedge-shaped space with both ends in the circumferential direction between the cylindrical surface 21. 22 is provided in the circumferential direction, and a roller 23 as an engaging member is incorporated between each cam surface 22 and the cylindrical surface 21, and the roller 23 is held by a cage 24.

  As shown in FIGS. 1 and 3, a spring accommodating recess 25 is formed on the other end surface of the cam ring 2, and a switch spring 26 is incorporated in the spring accommodating recess 25. The switch spring 26 has a C shape, and a pair of pressing pieces 26 a provided outward from both ends thereof are provided with a notch 27 formed in the peripheral wall of the spring accommodating recess 25 and a notch provided at the end of the cage 24. The neutral surfaces are inserted into the inner surface 28 and pressed against opposite sides in the circumferential direction of the notch 27 and the notch 28 in opposite directions, and each roller 23 is disengaged from the cylindrical surface 21 and the cam surface 22 by the pressing. The cage 24 is elastically held so as to be held in position.

  As shown in FIG. 1, an electromagnetic clutch 30 that controls the engagement and disengagement of the two-way clutch 20 is provided between the outer ring 1 and the cage 24 in addition to the two-way clutch 20. .

  The electromagnetic clutch 30 includes an armature 31 disposed to face the end face of the cage 24, 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.

  An engagement hole 34 is formed in the armature 31 at a position facing the end surface of the retainer 24, and a projecting piece 35 provided on the end surface of the retainer 24 is engaged with the engagement hole 34. The armature 31 is prevented from rotating with respect to the retainer 24 and is movable in the axial direction.

  The rotor 32 has a U-shaped cross section provided with cylindrical portions 32b and 32c facing in the same direction on the outer periphery and inner periphery of the disc portion 32a, and the outer cylindrical portion 32b is a nonmagnetic member connected to the open end of the outer ring 1. It is fitted in a rotor guide 36 made of a body and is prevented from rotating.

  An annular groove 37 is formed on the disk portion 32 a of the rotor 32 on the surface facing the armature 31, and a separation spring 38 for urging the armature 31 in a direction away from the rotor 32 is incorporated in the annular groove 37. It is.

  In addition, a plurality of arc-shaped slits 39 are formed on the side surface in the annular groove 37, and the permanent magnet 40 that applies an attractive force to the armature 31 and attracts the armature 31 to the rotor 32 in each slit 39 has the same magnetic pole. They are built in the same direction so that they face the same direction.

  The electromagnet 33 includes an electromagnetic coil 33a and a core 33b that supports the electromagnetic coil 33a, and the core 33b is supported by a stationary member. Here, when the electromagnetic coil 33 a of the electromagnet 33 is energized, the magnetic flux of the permanent magnet 40 is weakened, and the armature 31 is separated from the rotor 32 by pressing of the separation spring 38.

  The rotation transmission device shown in the embodiment has the above-described structure. FIG. 1 shows a state in which the electromagnet 33 is energized with respect to the electromagnetic coil 33a, and the armature 31 is separated from the rotor 32 by the pressing of the separation spring 38. Further, as shown in FIG. 2I, the roller 23 is held at a neutral position where the engagement with the cylindrical surface 21 and the cam surface 22 is released.

  For this reason, even if rotational torque is input to the torque transmission shaft 4 and the cam ring 2 rotates, the rotation is not transmitted to the outer ring 1 and the cam ring 2 rotates freely.

  When the energization of the electromagnetic coil 33a is interrupted in the rotating state of the cam ring 2, the armature 31 is attracted to the rotor 32 by the attractive force applied to the armature 31 from the permanent magnet 40, and the frictional resistance acting on the attracting surface is maintained by the cage. Since the rotation resistance is 24, the cam ring 2 and the cage 24 rotate relative to each other. Due to the relative rotation, as shown in FIG. 2 (II), the roller 23 is engaged with the cylindrical surface 21 and the cam surface 22 and the two-way clutch 20 is engaged, and the rotation of the cam ring 2 is performed via the roller 23. It is transmitted to the outer ring 1.

  Here, when the cam ring 2 and the cage 24 rotate relative to each other, the switch spring 26 is elastically deformed. Therefore, when the electromagnetic coil 33a is energized and the armature 31 is separated from the rotor 32 by the pressing of the separation spring 38, the cage 24 is rotated by the restoring elasticity of the switch spring 26, and the roller 23 has the cylindrical surface 21 and the cam surface. 22 is returned to the neutral position where the engagement is released.

  As shown in the embodiment, by providing a twist angle θ to the spline teeth 5a formed on the outer periphery of the torque transmission shaft 4, the backlash in the rotational direction at the fitting portion between the torque transmission shaft 4 and the cam ring 2 is reduced. Can do. For this reason, even if the rotation direction of the torque transmission shaft 4 is switched, no abnormal noise is generated.

  In the embodiment, the armature 31 is attracted to the rotor 32 by the attractive force of the permanent magnet 40 by releasing the energization of the electromagnetic coil 33a. However, the permanent magnet 40 is omitted, and the energization of the electromagnetic coil 33a is performed. The armature 31 may be attracted to the rotor 32.

  7 to 9 show other examples of the spline 5. 7 to 9 show the initial state of the spline 5 fitting. In this example, the width dimension a of the spline teeth 5a formed on the outer periphery of the shaft end of the torque transmission shaft 4 is made smaller than the width dimension b of the spline groove 5b provided on the inner periphery of the cam ring 2, and the spline groove 5b is formed in a straight shape parallel to the axis, and a twist angle θ that is press-fitted into the spline groove 5b is given to the spline teeth 5a.

  As described above, by making the width dimension a of the spline teeth 5a smaller than the width dimension b of the spline grooves 5b, and imparting a twist angle θ that is press-fitted into the straight spline grooves 5b to the spline teeth 5a, As shown in FIG. 9, in the initial fitting of the spline teeth 5a and the spline grooves 5b, a gap 50 is formed between the opposing side surfaces of the spline teeth 5a and the spline grooves 5b.

  For this reason, since the initial fitting of the spline teeth 5a and the spline grooves 5b is a clearance fit, the spline teeth 5a can be easily inserted into the spline grooves 5b. When the spline teeth 5a are inserted into the spline grooves 5b, the front end of one side of the spline teeth 5a and the rear end of the other side come into contact with both side surfaces of the spline grooves 5b during the insertion. It is possible to obtain a connection state with no play in the rotation direction.

  FIG. 10 (I) shows another example of the retaining means 10. In this example, a ring housing groove 12 is formed on the inner periphery of the cam ring 2, an engagement groove 11 is formed on the outer periphery of the torque transmission shaft 4, and the straddle straddles the engagement groove 11 and the ring housing groove 12. A ring 13 is incorporated, and a tapered surface 6 for expanding the retaining ring is formed on the outer periphery of the shaft end in the insertion direction of the torque transmission shaft 4 with respect to the cam ring 2.

  Here, the ring housing groove 12 has a depth capable of housing the entire retaining ring 13 in the expanded state, while the groove depth of the engaging groove 11 is smaller than the wire diameter of the retaining ring 13.

  In the retaining means 10 configured as described above, when the torque transmission shaft 4 is inserted into the inner periphery of the cam ring 2 with the retaining ring 13 incorporated in the ring receiving groove 12, as shown in FIG. 10 (II). Since the small-diameter end of the tapered surface 6 enters the retaining ring 13, the diameter of the retaining ring 13 can be increased by the tapered surface 6. When the torque transmission shaft 4 is inserted to a position where the engaging groove 11 faces the retaining ring 13, the retaining ring 13 is contracted by its own restoring elasticity and engaged with the engaging groove 11. The retaining ring 13 can be easily attached at a position straddling the accommodation groove 12 and the engagement groove 11.

Longitudinal front view showing an embodiment of a rotation transmission device according to the present invention (I) is a sectional view taken along the line II-II in FIG. 1, and (II) is a sectional view showing an engaged state of the two-way clutch. Sectional view along line III-III in FIG. Sectional drawing which shows the coupling | bond part of the cam ring and torque transmission shaft of FIG. Development view of spline teeth and spline grooves Sectional drawing which expands and shows the retaining means part of FIG. Sectional view showing another example of spline Sectional view along line VIII-VIII in FIG. Development view of spline teeth and spline grooves shown in FIG. (I) is a cross-sectional view showing another example of retaining means, (II) is a cross-sectional view showing a state at the start of insertion of the torque transmission shaft into the cam ring

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Cam ring 4 Torque transmission shaft 5 Spline 5a Spline tooth 5b Spline groove 6 Tapered surface 10 Detachment means 11 Engagement groove 12 Ring receiving groove 13 Retaining ring 23 Roller (engagement element)
24 Cage θ Torsion angle a Spline tooth width dimension b Spline groove width dimension

Claims (6)

A torque transmission shaft is fitted inside the cam ring incorporated inside the outer ring, and the torque transmission shaft and the cam ring are relatively prevented from rotating as a combination of splines, and an engagement element is provided between the inner periphery of the outer ring and the outer periphery of the cam ring. And a retainer for holding the engagement element, and by engaging the engagement element with the inner periphery of the outer ring and the outer periphery of the cam ring by relative rotation of the retainer and the cam ring, rotational torque is generated between the outer ring and the cam ring. In the rotation transmission device designed to transmit,
A rotation transmission device, wherein a twist angle is provided in at least one of spline teeth formed on the outer periphery of the torque transmission shaft and spline grooves formed on the inner periphery of the cam ring.   Twist angle at which the width dimension of the spline teeth is smaller than the width dimension of the spline grooves, one of the spline teeth and the spline grooves is a straight shape parallel to the axis, and the other is press-fitted into the spline grooves The rotation transmission device according to claim 1, wherein   The rotation transmission device according to claim 1, wherein a retaining means is provided between the fitting surfaces of the cam ring and the torque transmission shaft.   The retaining means forms an engaging groove extending in the circumferential direction on one side of the fitting surface, and a ring receiving groove extending in the circumferential direction on the other, and extends in a radial direction across the ring receiving groove and the engaging groove. The rotation transmission device according to claim 3, wherein a retaining ring that can be elastically deformed is attached, and a groove depth of the ring housing groove is a depth that can accommodate the entire retaining ring elastically deformed.   The ring receiving groove is formed on the inner periphery of the cam ring, the engaging groove is formed on the outer periphery of the torque transmission shaft, and a tapered surface for expanding the retaining ring is formed on the outer periphery of the shaft end in the insertion direction of the torque transmission shaft with respect to the cam ring. The rotation transmission device according to claim 4.   The rotation transmission device according to claim 4 or 5, wherein the retaining ring is made of a wire having a circular cross section.

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