JP2007239825A - Rotation transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable rotation transmission device capable of preventing erroneous engagement of a two-way clutch. <P>SOLUTION: A cam surface 12 is provided at an outer circumference of a cam ring 2 provided for an input shaft 1 and a roller 13 and a retainer 14 for holding the roller 13 are installed between the cam surface 12 and a cylinder surface 11 formed at an inner circumference of an outer ring 3. A switch spring 15 is installed between the retainer 14 and the input shaft 1 and an elastic force of the switch spring 15 is applied to both the input shaft 1 and the retainer 14 from a pair of pressing pieces 15b provided at both ends of the switch spring 15 to hold the roller 13 at a neutral position which is disengaged from the cam surface 12 and the cylinder surface 11. By gradually increasing axial width dimension of the pair of pressing pieces 15b provided at both the ends of the switch spring 15 toward a tip end, the pressing pieces 15b are likely to be applied with centrifugal force, the elastic force in a direction for expanding diameter of the switch spring 15 by the centrifugal force applied to the pressing pieces 15b is increased and erroneous engagement of the two-way clutch 10 at the time of idling of the input shaft 1 is prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  As this type of rotation transmission device, one described in Patent Document 1 has been conventionally known. In this rotation transmission device, an outer ring as an output side member is provided outside a cam ring as an input side member, a two-way clutch is incorporated between the cam ring and the outer ring, and the on / off of the two-way clutch is controlled by an electromagnetic clutch. I am doing so.

  Here, the two-way clutch has a cam surface that forms a wedge-shaped space between the outer periphery of the cam ring and a cylindrical surface formed on the inner periphery of the outer ring, and is incorporated between the cam surface and the cylindrical surface. The roller is held by a cage incorporated between the cam ring and the outer ring, and the spring force of the switch spring is applied to the cage, so that the roller is held in a neutral position where the roller is disengaged from the cam surface and the cylindrical surface. Is held elastic.

  On the other hand, the electromagnetic clutch attracts the armature, which is prevented from rotating with respect to the cage and supported so as to be movable in the axial direction, by energization of the electromagnetic coil of the electromagnet to the rotor which is prevented from rotating around the outer ring, It is connected to the outer ring.

  In the rotation transmission device configured as described above, when the armature is attracted to the rotor by energizing the electromagnetic coil of the electromagnet, the cage is rotated relative to the cam ring by the frictional resistance acting on the attracting surface, and the roller is the cylindrical surface and the cam. The rotation of the cam ring is transmitted to the outer ring through the roller by engaging with the surface.

  When energization of the electromagnetic coil of the electromagnet is released, the cage is returned to the neutral position by the spring force of the switch spring, the engagement of the roller with the cylindrical surface and the cam surface is released, and the cam ring is idled.

  By the way, in the conventional rotation transmission device, at the time of idling when only the cam ring rotates at high speed, the roller held by the cam ring and the cage rotates together, and the roller is moved radially outward by centrifugal force acting on the roller. There is a possibility that the cam ring and the cage may rotate relative to each other due to the drag torque acting on the cylindrical surface of the outer ring by moving, and the roller may be misengaged with the cam surface and the cylindrical surface. Is left.

  In addition, when the cam ring is idling while performing rapid acceleration / deceleration, the cam ring and the retainer, the armature and the roller rotate relative to each other due to the inertia of the retainer, the armature and the roller which are elastically coupled to the cam ring. There is a risk of misengaging with the cam surface and the cylindrical surface.

In order to eliminate such inconvenience, in the rotation transmission device described in Patent Document 2, the cylindrical portion provided in the armature is fitted inside the switch spring or the armature is fitted in a state where the electromagnet is de-energized. The protrusions provided are inserted between a pair of engaging pieces formed at both ends of the switch spring to prevent the switch spring from being reduced in diameter and to prevent the two-way clutch from being misengaged.
JP 11-336799 A Japanese Patent Laying-Open No. 2005-083560

  By the way, in the rotation transmission device described in Patent Document 2, the misengagement preventing function is established by inserting a cylindrical portion integrated with the armature into the inner diameter of the switch spring. However, the armature has a limitation on the axial movable distance, and in order to improve reliability, it is necessary to improve the accuracy of each part, leading to an increase in cost.

  Here, the reliability means that the cylinder part fits into the inner diameter of the switch spring when the clutch is idling and must be disengaged when the clutch is engaged. is there.

  An object of the present invention is to provide a reliable rotation transmission device capable of preventing misengagement of a two-way clutch.

  In order to solve the above-described problems, in the present invention, two directions for transmitting and blocking rotational torque between an input side member and an output side member provided outside the input member are provided. A clutch and an electromagnetic clutch for controlling engagement and disengagement of the two-way clutch are incorporated, and the two-way clutch is formed on the outer periphery of the cam ring provided on the input side member and on the inner periphery of the output side member. Two directions in which a cam surface forming a wedge-shaped space is provided between the cylindrical surface and a roller assembled between the cam surface and the cylindrical surface is held by a cage assembled between the input side member and the output side member A notch provided with a C-shaped switch spring in a spring housing recess formed on the end face of the cam ring, and a pair of pressing pieces formed on both ends of the switch spring provided on the peripheral wall of the spring storage recess. So that the roller is elastically held at a neutral position where the roller is disengaged from the cylindrical surface and the cam surface by pressing both ends of the notch formed at the ends of the cage and the ends of the cage in opposite directions. In the rotation transmission device described above, the switch spring is provided with a weight portion that expands the diameter of the switch spring by the applied centrifugal force.

  Here, the pair of pressing pieces may be made to have a weight part such that the axial width dimension of the pair of pressing pieces gradually increases toward the tip, or the center of the C-shaped ring part reaches both ends. Accordingly, both end portions of the switch spring may be weight portions so that the width dimension in the radial direction is gradually increased.

  As described above, by providing the weight portion on the switch spring, when the input side member idles at high speed, the switch spring rotates together with the input side member, and centrifugal force acts on the weight portion of the switch spring. The elastic force in the direction of expanding the switch spring is prevented from being contracted due to the centrifugal force applied to the weight part. As a result, there is no inconvenience that the two-way clutch is misengaged during idling of the input side member, and a highly reliable rotation transmission device can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, a cam ring 2 is provided on an input shaft 1 as an input side member.

  An outer ring 3 as an output side member is provided outside the input shaft 1, and the outer ring 3 and the input shaft 1 are supported through a bearing 4 so as to be relatively rotatable.

  A two-way clutch 10 is provided between the input shaft 1 and the outer ring 3, and an electromagnetic clutch 20 that controls engagement and disengagement of the two-way clutch 10 is provided in parallel with the two-way clutch 10.

  The two-way clutch 10 forms a cylindrical surface 11 on the inner periphery of the outer ring 3, and a plurality of cam surfaces 12 forming a wedge-shaped space with the cylindrical surface 11 on the outer periphery of the cam ring 2 are spaced apart in the circumferential direction. And a two-way roller clutch in which a roller 13 is incorporated between each cam surface 12 and the cylindrical surface 11 and held by a retainer 14 incorporated between the input shaft 1 and the outer ring 3.

  Between the input shaft 1 and the cage 14, a switch spring 15 that elastically holds the cage 14 is incorporated in a neutral position where the roller 13 is disengaged from the cylindrical surface 11 and the cam surface 12.

  As shown in FIG. 3, the switch spring 15 has a configuration in which a pair of pressing pieces 15b are formed outward at both ends of the C-shaped ring portion 15a, and the pair of pressing pieces 15b are axially directed toward the tip. The width dimension is gradually increased to be a weight portion.

  As shown in FIG. 2, the switch spring 15 is assembled so that the ring portion 15 a is fitted into a spring accommodating recess 16 formed on the end surface of the cam ring 2, and the pair of pressing pieces 15 b are peripheral walls of the spring accommodating recess 16. Is inserted into a notch 18 provided on the end surface of the retainer 14 from the notch portion 17 formed in the inner surface, and the opposite end surfaces in the circumferential direction of the notch portion 17 and the notch 18 are pressed in opposite directions, and the press Thus, the roller 13 is held in the neutral position.

  As shown in FIG. 1, the electromagnetic clutch 20 includes an armature 21 that faces the end face of the cage 14 in the axial direction, a rotor 22 that faces the armature 21 in the axial direction, and an electromagnet that faces the rotor 22 in the axial direction. And a separation spring 24 that presses the armature 21 in a direction away from the rotor 22.

  An engagement hole 25 is formed in the armature 21, and a projecting piece 26 provided on the end surface of the retainer 14 is inserted into the engagement hole 25, and the armature 21 is engaged by the engagement between the projecting piece 26 and the engagement hole 25. Is prevented from rotating with respect to the retainer 14 and is movable in the axial direction.

  The rotor 22 has cylindrical portions 22 a and 22 b on the inner periphery and the outer periphery, and the outer peripheral cylindrical portion 22 b is press-fitted into a rotor guide 27 made of a nonmagnetic material attached in the opening end portion of the outer ring 3. It is locked.

  The electromagnet 23 includes a field core 23a and an electromagnetic coil 23b supported by the field core 23a. The electromagnet 23 is disposed between the outer cylindrical portions 22 a and 22 b of the rotor 22, and the field core 23 a is attached to the stationary member 28 for non-rotating support.

  The rotation transmission device shown in the embodiment has the above-described structure, and the roller 13 is held in a neutral state by the spring force of the switch spring 15 when the electromagnet 23 is de-energized with respect to the electromagnetic coil 23b. The rotation is not transmitted to the outer ring 3, and the input shaft 1 rotates idle.

  When the electromagnetic coil 23 b of the electromagnet 23 is energized while the input shaft 1 is rotating, an attractive force is applied to the armature 21, and the armature 21 moves against the elasticity of the separation spring 24 and is attracted to the rotor 22.

  The frictional resistance acting on the attracting surfaces of the rotor 22 and the armature 21 becomes the rotational resistance of the cage 14, and the frictional resistance is set to a value larger than the spring force of the switch spring 15, so that the switch spring 15 is elastically deformed. As a result, the input shaft 1 and the cage 14 rotate relative to each other. By the relative rotation, the roller 13 is pushed into the narrow portion of the wedge-shaped space and engaged with the cylindrical surface 11 and the cam surface 12, and the rotation of the input shaft 1 is transmitted to the outer ring 3 through the roller 13.

  In the state of torque transmission from the input shaft 1 to the outer ring 3, when the energization to the electromagnetic coil 23b is cut off, the retainer 14 is rotated in the reverse direction when engaged with the input shaft 1 by the spring force of the switch spring 15, and the roller 13 is released from the cylindrical surface 11 and the cam surface 12 and returned to the neutral position. For this reason, the rotation transmission from the input shaft 1 to the outer ring 3 is interrupted.

  In the idling state of the input shaft 1, the input shaft 1 and the cage 14 are elastically connected by the switch spring 15, so that the input shaft 1, the cage 14, and the roller 13 held by the cage 14 are both Rotate.

  For this reason, when the input shaft 1 idles, the roller 13 moves radially outward by centrifugal force to contact the cylindrical surface 11, and drag torque is generated in the cage 14 by the frictional resistance acting on the contact portion. Since this drag torque acts against the elastic holding force of the switch spring 15, when the drag torque becomes larger than the elastic holding force, the cage 14 rotates relative to the input shaft 1 and the roller 13 rotates to the cylindrical surface 11. In addition, the cam surface 12 is misengaged.

  However, when the input shaft 1 idles, the switch spring 15 rotates together with the input shaft 1, and the pair of pressing pieces 15b provided on the switch spring 15 has a sector shape in which the axial width gradually increases toward the tip. Thus, the pair of pressing pieces 15b are easily subjected to centrifugal force, and the switch spring 15 is contracted by increasing the elastic force in the direction of expanding the diameter by the centrifugal force applied to the pressing piece 15b. The diameter is prevented.

  As a result, the cage 14 does not rotate relative to the input shaft 1, and there is no inconvenience that the two-way clutch 10 is misengaged when the input shaft 1 is idling.

  4 and 5 show other examples of the switch spring 15. The switch spring 15 shown here has a gradually increasing width in the radial direction from the center of the C-shaped ring portion of the ring portion 15a to both ends.

  As described above, by gradually increasing the width dimension of the ring portion 15a in the radial direction from the center of the C-shaped ring portion to both ends, the switch spring 15 has both ends of the ring portion 15a function as weight portions. Therefore, the switch spring 15 is prevented from being contracted due to an increase in the elastic force in the direction of expanding the diameter due to the centrifugal force applied to both ends thereof.

  Therefore, by employing the switch spring 15 as described above, it is possible to prevent the two-way clutch 10 from being misengaged when the input shaft 1 is idling.

A longitudinal front view showing an embodiment of a rotation transmission device according to the present invention Sectional view along the line II-II in FIG. Perspective view showing switch spring Sectional view of rotation transmission device using other switch springs 4 is a perspective view of the switch spring shown in FIG.

Explanation of symbols

1 Input shaft (input side member)
2 Cam ring 3 Outer ring (output side member)
10 Two-way clutch 11 Cylindrical surface 12 Cam surface 13 Roller 14 Cage 15 Switch spring 15b Pressing piece 16 Spring housing recess

Claims (3)

A two-way clutch that transmits and shuts off rotational torque between the input side member and an output side member provided outside the input side member, and engagement and disengagement of the two-way clutch An electromagnetic clutch for controlling the cam, and the two-way clutch forms a wedge-shaped space between the outer periphery of the cam ring provided on the input side member and the cylindrical surface formed on the inner periphery of the output side member A spring housing formed on the end face of the cam ring, comprising a two-way roller clutch provided with a surface and a roller assembled between the cam surface and the cylindrical surface held by a cage incorporated between the input side member and the output side member A C-shaped switch spring is incorporated in the recess, and a pair of pressing pieces formed at both ends of the switch spring are formed at both ends of the notch provided on the peripheral wall of the spring housing recess and at the end of the retainer. Both ends In the rotation transmitting device roller by the action of pressing the direction is such that the elastic holding the retainer in a neutral position that is disengaged with respect to the cylindrical surface and the cam surface against,
A rotation transmission device characterized in that a weight portion for expanding the diameter of the switch spring by a centrifugal force applied to the switch spring is provided.   The rotation transmission device according to claim 1, wherein the pair of pressing pieces has an axial width that is widened toward the tip to form a weight portion.   The rotation transmission device according to claim 1, wherein the switch spring is configured such that a radial width dimension gradually increases from the center of the C-shaped ring portion to both ends, and both end portions of the switch spring are weight portions.

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