JP2019056417A - Joint for torque transmission and electric power steering device - Google Patents

Abstract

To provide a structure capable of suppressing occurrence of noise upon inverting a rotational direction of a drive shaft.SOLUTION: To both side parts in an axis direction of an intermediate convexoconcave part 19 provided at a radial inside part of an intermediate transmission member 17, an end part convexoconcave part 23 provided at a radial outside part of a pair of end part transmission members 18 is engaged. Between a circumferential side surface of a convex part 21 constituting the intermediate convexoconcave part 19 and a circumferential side surface of a convex part 25 constituting the end part convexoconcave part 23, a circumferential spring part 22 provided integrally with the intermediate transmission member 17 is arranged.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a torque transmission joint that is incorporated in various mechanical devices and transmits torque between a drive shaft and a driven shaft, and an electric power steering device.

  FIGS. 16 and 17 show an example of an electric power steering apparatus which has been conventionally known as described in Japanese Patent Application Laid-Open No. 2004-306898 and the like. A front end portion of the steering shaft 2 having the steering wheel 1 attached to the rear end portion is rotatably supported in the housing 3, and a worm wheel 4 is fixed to a portion driven to rotate by the steering shaft 2. . A worm tooth 5 that meshes with the worm wheel 4 is provided at an intermediate portion in the axial direction of the worm shaft 6, and both end portions in the axial direction of the worm 8 that is rotationally driven by the electric motor 7 are a pair of rolling bearings such as a deep groove type ball bearing. 9a and 9b are rotatably supported in the housing 3. A pressing piece 10 is fitted on a portion of the tip end of the worm shaft 6 protruding from the rolling bearing 9 a, and an elastic member such as a coil spring 11 is provided between the pressing piece 10 and the housing 3. ing. The coil spring 11 biases the worm teeth 5 of the worm shaft 6 toward the worm wheel 4 through the pressing piece 10. With such a configuration, backlash between the worm tooth 5 and the worm wheel 4 is suppressed, and generation of rattling noise is suppressed.

  In the conventional electric power steering device, it is possible to suppress the occurrence of rattling noise at the meshing portion between the worm tooth 5 and the worm wheel 4, but the distal end portion of the output shaft 12 of the electric motor 7 and the proximal end of the worm shaft 6. There is room for improvement in terms of suppressing abnormal noise generated at the joint with the part. This point will be described below.

  In the conventional electric power steering device, the distal end portion of the output shaft 12 of the electric motor 7 and the proximal end portion of the worm shaft 6 are provided at the proximal end portion of the worm shaft 6 so as to be able to transmit torque. The spline hole 13 and the spline shaft portion 14 provided at the distal end portion of the output shaft 12 are spline-engaged. If the spline shaft portion 14 and the spline hole 13 are in spline engagement in a state where the circumferential clearance is zero, that is, in a state where no backlash exists, the distal end portion of the output shaft 12 and the proximal end of the worm shaft 6 No noise is generated at the spline engaging portion with the portion. Actually, however, backlash exists in the spline engaging portion. In particular, in the structure that suppresses the backlash between the worm tooth 5 and the worm wheel 4, the backlash of the spline engaging portion cannot be completely eliminated because the worm shaft 6 needs to be oscillated and displaced. For this reason, there is room for improvement in terms of suppressing the occurrence of abnormal noise based on the presence of such backlash.

  On the other hand, in Japanese Patent Application Laid-Open No. 2012-131249, the output shaft of the electric motor and the worm shaft are coupled to each other via a metal, cylindrical power transmission member, so that the worm shaft is smoothly displaced. The structures that can be made are described. However, even in such a structure, in order to swing and displace the worm shaft, the spline shaft portions provided at both ends of the power transmission member and the worm shaft and the output shaft of the electric motor are provided at the respective end portions. Each of the spline engaging portions with the spline holes has backlash. For this reason, there is room for improvement in terms of suppressing the occurrence of abnormal noise based on the presence of such backlash.

JP 2004-306898 A JP 2012-131249 A

  The present invention has been made in view of the circumstances as described above, and an object thereof is to provide a torque transmission joint that can suppress the occurrence of abnormal noise when reversing the rotation direction of a drive shaft. It is.

The torque transmission joint according to the present invention includes an intermediate transmission member and a pair of end transmission members.
The intermediate transmission member has intermediate concave and convex portions formed by alternately arranging concave portions and convex portions with respect to the circumferential direction on one side portion in the radial direction.
The pair of end transmission members are arranged one by one on both sides in the axial direction of the intermediate transmission member, and are formed by alternately arranging recesses and projections on the other radial side in the circumferential direction. Convex and concave portions, and the convex portions constituting the end concave and convex portions are engaged with the concave portions constituting the intermediate concave and convex portions.
Further, a circumferential spring portion provided integrally with the intermediate transmission member between a circumferential side surface of the convex portion constituting the intermediate uneven portion and a circumferential side surface of the convex portion constituting the end uneven portion. However, these circumferential side surfaces are urged in a direction away from each other in the circumferential direction, and are arranged in a state in which circumferential deformation is possible.

In the torque transmission joint according to the present invention, the circumferential spring portion can be configured as a cantilever leaf spring in which only one end portion in the radial direction is coupled to the intermediate transmission member. .
Moreover, the said circumferential direction spring part can be comprised in the arch-shaped leaf | plate spring shape with which only the radial direction both ends were couple | bonded with respect to the said intermediate transmission member.

  In the torque transmission joint according to the present invention, the intermediate transmission member is integrally provided between a bottom surface of the concave portion constituting the intermediate uneven portion and a radial other end surface of the convex portion constituting the end uneven portion. The radial spring portion is arranged in such a manner that these both surfaces are urged in the radial direction and can be deformed in the radial direction.

In the torque transmission joint according to the present invention, the radial spring portion can be configured as a cantilever leaf spring in which only one end portion in the circumferential direction is coupled to the intermediate transmission member. .
Further, the radial spring portion can be configured as an arched leaf spring shape in which only circumferential end portions are coupled to the intermediate transmission member.

The electric power steering apparatus of the present invention includes a housing, a worm wheel, a worm, an electric motor, and a torque transmission joint.
The worm wheel is rotatably supported with respect to the housing.
The worm has a worm shaft and worm teeth provided on an outer peripheral surface of the worm shaft, and is rotatably supported with respect to the housing in a state where the worm teeth are engaged with the worm wheel. .
The electric motor has an output shaft for rotationally driving the worm.
The torque transmission joint connects the output shaft of the electric motor and the worm shaft so that torque transmission is possible.
In particular, in the electric power steering apparatus of the present invention, the torque transmission joint is the torque transmission joint of the present invention, and any one of the pair of end transmission members is the end transmission member. It is fixed or integrally molded to the distal end portion of the output shaft of the electric motor, and the other end transmission member of the pair of end transmission members is fixed or integrally molded to the base end portion of the worm shaft. .

  In the electric power steering apparatus according to the present invention, the worm is swingable with respect to the output shaft of the electric motor, and the worm is disposed between the tip of the worm shaft and the housing. A configuration having an urging mechanism that urges toward the position can be employed.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of abnormal noise can be suppressed when reversing the rotation direction of the drive side edge part transmission member among a pair of edge part transmission members.

FIG. 1 is a diagram corresponding to FIG. 17 regarding the first example of the embodiment. FIG. 2 is an enlarged view of part A of FIG. FIG. 3 is a view of the torque transmission joint in the first example of the embodiment of the present invention as seen from the outside in the radial direction. 4 is a view from the right or left side of FIG. 5 is a cross-sectional view taken along the line BB in FIG. 6 is a cross-sectional view taken along the line CC or the line DD in FIG. FIG. 7 is a view of a part in the circumferential direction of the intermediate transmission member as viewed from the axial direction regarding the first example of the embodiment. 8 is a cross-sectional view taken along line EE in FIG. FIG. 9 is a diagram illustrating an end transmission member according to the first example of the embodiment. Specifically, FIG. 9A is a view as seen from the left side of FIG. 9B, and FIG. 9B is a cross-sectional view taken along line FF of FIG. 9A. FIG. 10 is a diagram corresponding to FIG. 7 regarding the second example of the embodiment. FIG. 11 is a diagram corresponding to FIG. 7 regarding the third example of the embodiment. FIG. 12 is a diagram corresponding to FIG. 7 regarding the fourth example of the embodiment. FIG. 13 is a diagram corresponding to FIG. 7 regarding the fifth example of the embodiment. 14 is a cross-sectional view taken along the line GG in FIG. FIG. 15 is a diagram corresponding to FIG. 7 regarding the sixth example of the embodiment. FIG. 16 is a partially cutaway side view showing an example of a conventional structure of an electric power steering apparatus. FIG. 17 is an enlarged HH sectional view of FIG.

[First example of embodiment]
A first example of the embodiment will be described with reference to FIGS.
In the electric power steering apparatus of this example, the front end portion of the steering shaft 2 having the steering wheel 1 attached to the rear end portion can be rotated in the housing 3 as in the conventional structure shown in FIGS. The worm wheel 4 is fixed to a portion that is rotationally driven by the steering shaft 2. A worm tooth 5 that meshes with the worm wheel 4 is provided at an intermediate portion in the axial direction of the worm shaft 6a, and both axial ends of the worm 8 that is rotationally driven by the electric motor 7 have a pair of rolling bearings 9a such as a deep groove ball bearing. , 9b is rotatably supported in the housing 3.

  An urging mechanism 15 including an elastic body such as a coil spring or a leaf spring is provided between the housing 3 and the rolling bearing 9a fitted on the tip of the worm shaft 6a. By the urging mechanism 15, the worm teeth 5 of the worm shaft 6 a are pressed toward the worm wheel 4, that is, urged based on the elasticity of the elastic body. With such a configuration, backlash between the worm tooth 5 and the worm wheel 4 is suppressed, and generation of rattling noise is suppressed.

  In this example, the distal end portion of the output shaft 12a of the electric motor 7 serving as the drive shaft and the proximal end portion of the worm shaft 6a serving as the driven shaft, which are arranged in series with each other in the axial direction, are the torque transmission joint 16. It is coupled to enable transmission of torque via the.

  The torque transmission joint 16 includes an intermediate transmission member 17 and a pair of end transmission members 18. In the following description, the axial direction inside and outside of each member constituting the torque transmission joint 16 is based on the axial central portion of the torque transmission joint 16 in the assembled state. . That is, the axially central side of the torque transmission joint 16 is the inner side in the axial direction, and both axial sides of the torque transmission joint 16 are the outer side in the axial direction.

  The intermediate transmission member 17 is a member that is disposed at an intermediate portion in the axial direction of the torque transmission joint 16. The intermediate transmission member 17 is, for example, a belt material in which rubber is reinforced with cloth, a synthetic resin (PPS, PEEK, polyamide, etc.) mixed with reinforcing fibers as necessary, or a metal such as an iron alloy, a copper alloy, or an aluminum alloy. Thus, the whole is formed in an annular shape by a method such as injection molding, casting, forging or cutting.

  The intermediate transmission member 17 has an intermediate uneven portion 19 in the circumferential direction on the inner peripheral portion. The intermediate concavo-convex portion 19 is configured by alternately arranging the concave portions 20 and the convex portions 21 in the circumferential direction. In other words, the intermediate transmission member 17 has convex portions 21 protruding radially inward at equal intervals in the circumferential direction, and the gap between the convex portions 21 adjacent in the circumferential direction is the concave portion 20. It has become.

  The intermediate transmission member 17 further includes a plurality of circumferential spring portions 22 formed integrally with the intermediate transmission member 17. The circumferential direction spring part 22 is arrange | positioned 1 each in the location (a total of 4 places with respect to one convex part 21) adjacent to the circumferential direction both sides of the axial direction both sides of the convex part 21, respectively. The circumferential spring portion 22 is a rectangular plate-like body in which the radially inner end portion is coupled to the circumferential end portion of the radially inner end portion (tip portion) of the convex portion 21, and in a free state, Increasing in the radial direction is inclined in a direction away from the circumferential side surface of the convex portion 21. That is, the circumferential spring portion 22 is configured as a cantilevered leaf spring with the radially inner end supported. When the intermediate transmission member 17 is manufactured, the circumferential spring portion 22 can be formed simultaneously with other portions by, for example, a method such as injection molding or casting, or can be cut after forming the other portions. It can also be formed by a method.

  The pair of end transmission members 18 are members that are arranged one by one on both sides in the axial direction of the torque transmission joint 16. As shown in FIG. 9, the end transmission member 18 is formed by injection molding, casting, forging, sintering, using a synthetic resin mixed with reinforcing fibers as necessary, or a metal such as an iron alloy, a copper alloy, or an aluminum alloy. The whole is formed in an annular shape by a method such as cutting.

  One of the pair of end transmission members 18 (on the right side in FIGS. 2, 3, and 5) has an end transmission member 18 with respect to the tip of the output shaft 12 a (FIG. 1) and 1 The other end transmission member 18 (left side in FIGS. 2, 3 and 5) of the pair of end transmission members 18 is an interference fit with the base end of the worm shaft 6a (FIG. 1). The outer fitting is fixed in a state where relative rotation and relative displacement in the axial direction are prevented by spline fitting, caulking, or the like. However, when carrying out the present invention, the end portion transmission member 18 may be formed integrally with the distal end portion of the output shaft 12a or the proximal end portion of the worm shaft 6a.

  The end portion transmission member 18 has end uneven portions 23 formed by alternately arranging concave portions 24 and convex portions 25 in the circumferential direction at the inner end portion or the intermediate portion in the axial direction of the outer peripheral surface. Moreover, the end part transmission member 18 has the annular | circular shaped collar part 26 in the axial direction outer end part of an outer peripheral surface. The axially outer end opening of the recess 24 constituting the end uneven portion 23 is closed by the axially inner side surface of the flange portion 26. In addition, when implementing this invention, the collar part 26 can also be abbreviate | omitted.

  The pair of end portion transmission members 18 have respective inner ends in the axial direction or intermediate portions inserted into the radially inner sides of both side portions in the axial direction of the intermediate transmission member 17. In this state, as shown in FIGS. 5 and 6, for example, as shown in FIGS. 5 and 6, the convex portion 25 of the end uneven portion 23 constituting the pair of end portion transmitting members 18 is a concave portion of the intermediate uneven portion 19 constituting the intermediate transmitting member 17. 20 is arranged inside. Further, in this state, there is a gap for allowing the misalignment between the circumferential side surfaces of the convex portion 25 of the end concave and convex portion 23 and the circumferential side surface of the convex portion 21 of the intermediate concave and convex portion 19. Existing. At the same time, the circumferential spring 22 biases these gaps in the direction of moving away the circumferential side surface of the convex portion 25 of the end uneven portion 23 and the circumferential side surface of the convex portion 21 of the intermediate uneven portion 19 in the circumferential direction. In addition, they are arranged in a state in which they can be deformed in the circumferential direction. Specifically, the radially outer end portions (tip portions) of the circumferential spring portions 22 are in elastic contact with both circumferential sides of the convex portion 25 of the end uneven portion 23. Further, in this state, a gap α is interposed between the circumferential spring portion 22 and the circumferential side surface of the convex portion 21 of the intermediate uneven portion 19.

  Furthermore, in this example, in this state, a radial gap β is interposed between the radially outer end surface (tip surface) of the convex portion 25 of the end uneven portion 23 and the bottom surface of the concave portion 20 of the intermediate uneven portion 19. In addition, a radial gap γ is interposed between the bottom surface of the concave portion 24 of the end uneven portion 23 and the radially inner end face (tip surface) of the convex portion 21 of the intermediate uneven portion 19. Based on the existence of these radial gaps β and γ, misalignment (inclination, axial misalignment, etc.) between the intermediate transmission member 17 and the pair of end transmission members 18 is allowed. Yes.

  In the electric power steering apparatus of this example, the torque of the output shaft 12 a is transmitted in the order of one end transmission member 18 → the intermediate transmission member 17 → the other end transmission member 18 → the worm 8. That is, the rotational torque of the output shaft 12a is transmitted from the one end transmission member 18 to the intermediate transmission member 17 through the engagement portion between the end uneven portion 23 and the intermediate uneven portion 19 of the one end transmission member 18. The Further, the torque transmitted to the intermediate uneven portion 19 is transmitted to the other end transmission member 18 and the worm 8 through the engaging portion between the intermediate uneven portion 19 and the end uneven portion 23 of the other end transmission member 18. The

  In particular, in this example, when torque is transmitted through any of these engaging portions, the convex portion 25 of the end uneven portion 23 and the convex portion 21 of the intermediate uneven portion 19 face each other in the initial stage. The intermediate transmission member 17 and the pair of end portion transmission members 18 rotate relative to each other based on the existence of a gap existing between the circumferential side surfaces. However, the momentum of this relative rotation is weakened by the circumferential spring portion 22 disposed in the gap being bent in the circumferential direction. Therefore, after that, when the gap α disappears and the circumferential spring portion 22 contacts the circumferential side surface of the convex portion 21 of the intermediate uneven portion 19, that is, the convex portion 25 of the end uneven portion 23 and the intermediate uneven portion. Even when the circumferential side surfaces facing each other with the 19 convex portions 21 come into contact with each other via the circumferential spring portion 22, the force of the contact is weakened, and the generation of noise due to the contact can be suppressed.

  In this example, when the rotation direction of the output shaft 12a of the electric motor 7 is reversed, the convex portion 25 of the end concave and convex portion 23 and the convex portion 21 of the intermediate concave and convex portion 19 are also provided for the same reason as described above. The momentum at which the circumferential side surfaces facing each other come into contact with each other via the circumferential spring portion 22 is weakened, and the generation of abnormal noise accompanying the contact can be suppressed.

  In other words, in the electric power steering apparatus of this example, the torsional rigidity of the torque transmission joint 16 becomes low due to the bending of the circumferential spring portion 22 having low rigidity in the initial stage of torque transmission, and then the circumferential direction. The spring portion 22 has a two-stage characteristic that becomes high when the spring portion 22 contacts the circumferential side surface of the convex portion 21 of the intermediate uneven portion 19. When the present invention is carried out, the torsional rigidity of the torque transmission joint at the initial stage of torque transmission can be adjusted by changing the shape and size of the circumferential spring portion.

  Moreover, in this example, the circumferential spring part 22 which exists in the engaging part of the edge uneven | corrugated | grooved part 23 of one end part transmission member 18 and the intermediate | middle uneven | corrugated part 19, and the edge unevenness | corrugation of the other edge transmission member 18 are demonstrated. The circumferential spring portion 22 existing in the engaging portion between the portion 23 and the intermediate uneven portion 19 is provided independently of each other. For this reason, the variation in the shape existing in each engaging portion is appropriately affected by the circumferential spring portion 22 existing in each engaging portion (that is, the influence of the variation in shape existing in the mating engaging portion is affected. Can absorb)

[Second Example to Fourth Example of Embodiment]
Second to fourth examples of the embodiment will be described with reference to FIGS.
In the second to fourth examples of the embodiment, the shape of the circumferential spring portion is different from the first example of the embodiment described above.

  Specifically, in the second example of the embodiment shown in FIG. 10, the circumferential spring portion 22 a is only part of the intermediate transmission member 17 in the radial outer end portion (near the proximal end portion of the convex portion 21). Further, in a free state, it is inclined in a direction away from the circumferential side surface of the convex portion 21 toward the inner side in the radial direction. In other words, the circumferential spring portion 22a is configured as a cantilever leaf spring with the radially outer end supported. In a state where the torque transmission joint is assembled, the radially inner end portion of the circumferential spring portion 22a elastically contacts the circumferential side surface of the convex portion constituting the end uneven portion.

  In the third example of the embodiment shown in FIG. 11, the circumferential spring portion is divided into a radially inner circumferential spring portion 22 b and a radially outer circumferential spring portion 22 c. The radially inner circumferential spring portion 22b has the same configuration as the circumferential spring portion 22 of the first example of the embodiment. In contrast, the radially outer circumferential spring portion 22c has the same configuration as the circumferential spring portion 22a of the second example of the embodiment. In addition, the distal end portion of the radially inner circumferential spring portion 22b and the distal end portion of the radially outer circumferential spring portion 22c face each other in the radial direction.

In the third example of the embodiment shown in FIG. 12, the circumferential spring portion 22 d is a part of the intermediate transmission member 17 only at both radial ends (the distal end portion of the convex portion 21 and the proximal end of the convex portion 21. And in the free state, the radially intermediate portion protrudes toward the center in the circumferential direction of the recess 20 as compared to the both ends in the radial direction. That is, the circumferential spring portion 22 d is configured in an arched leaf spring shape in which only both ends in the radial direction are coupled to the intermediate transmission member 17. In a state where the torque transmission joint is assembled, the radial intermediate portion of the circumferential spring portion 22d elastically contacts the circumferential side surface of the convex portion constituting the end uneven portion.
Other configurations and operations are the same as those of the first example of the embodiment.

[Fifth Example of Embodiment]
A fifth example of the embodiment will be described with reference to FIGS. 13 and 14.
In this example, the intermediate transmission member 17 further includes a plurality of radial spring portions 27 formed integrally with the intermediate transmission member 17. The radial spring portions 27 are arranged one by one at locations adjacent to the inside in the radial direction of both axial sides of the bottom surface of the recess 20 (two locations in total for one recess 20). The radial spring portion 27 is a rectangular plate-like body whose one end portion in the circumferential direction is coupled to a part of the intermediate transmission member 17 (the base end portion of the convex portion 21), and in the free state, one end in the circumferential direction. As it goes from the portion toward the other end in the circumferential direction, it is inclined in a direction away from the bottom surface of the recess 20. That is, the radial direction spring part 27 is comprised by the cantilever type leaf | plate spring shape by which the circumferential direction one end part was supported.

  Further, in the assembled state of the torque transmission joint of this example, the radially outer end surface (tip surface) of the convex portion 25 of the end uneven portion 23 constituting the pair of end portion transmitting members 18 and the intermediate uneven portion 19. Each of the radial spring portions 27 urges the gaps between the bottom surface of the concave portion 20 and the radial outer end surface of the convex portion 12 and the bottom surface of the concave portion 20 in the radial direction. It arrange | positions in the state in which the bending deformation of a direction is possible. Specifically, the other circumferential end of the radial spring portion 27 is in elastic contact with the radially outer end surface of the convex portion 25. In this state, a gap δ is interposed between the radial spring portion 27 and the bottom surface of the recess 20.

In such a structure of the present example, it is possible to prevent an unnecessary inclination or axial misalignment between the intermediate transmission member 17 and the pair of end transmission members 18 based on the elasticity of the radial spring 27.
Other configurations and operations are the same as those of the first example of the embodiment.

[Sixth Example of Embodiment]
A sixth example of the embodiment will be described with reference to FIG.
In the sixth example of the embodiment, the form of the circumferential spring portion is different from the fifth example of the embodiment described above.

  Specifically, in the sixth example of the embodiment, only the both ends in the circumferential direction of the radial spring portion 27a are coupled to a part of the intermediate transmission member 17 (the base end portion of the convex portion 21 adjacent in the circumferential direction). In the free state, the intermediate portion in the circumferential direction projects radially inward from both ends in the circumferential direction. That is, the radial spring portion 27 a is configured in an arched leaf spring shape in which only both circumferential ends are coupled to the intermediate transmission member 17.

Further, in the assembled state of the torque transmission joint of this example, the circumferential intermediate portion of the radial spring portion 27a elastically contacts the radially outer end surface (tip surface) of the convex portion 25 of the end uneven portion 23. ing.
Other configurations and operations are the same as in the fifth example of the embodiment.

  In the case of carrying out the present invention, a portion of the axially outer side surface (both side surfaces) of the intermediate transmission member 17 that faces the axially inner side surface of the flange portion 26 constituting the end portion transmission member 18 is It can also be set as the inclined surface part which inclined in the direction which goes to an axial direction inner side, so that it goes to a radial direction outer side. If such a configuration is adopted, even when misalignment occurs between the intermediate transmission member 17 and the end transmission member 18, the axially outer side surface of the intermediate transmission member 17 and the end transmission member 18 are configured. It is possible to make it difficult for the inner surface of the collar portion 26 to come into contact with each other.

  When implementing the present invention, it is possible to employ a configuration in which the configurations of the above-described embodiments are appropriately combined within a range in which no contradiction occurs.

  When carrying out the present invention, it is also possible to adopt a configuration in which an intermediate uneven portion is provided on the radially outer portion of the intermediate transmission member and an end uneven portion is provided on the radially inner portion of the end transmission member. .

DESCRIPTION OF SYMBOLS 1 Steering wheel 2 Steering shaft 3 Housing 4 Worm wheel 5 Worm tooth | gear 6, 6a Worm shaft 7 Electric motor 8 Worm 9a, 9b Rolling bearing 10 Pressing piece 11 Coil spring 12, 12a Output shaft 13 Spline hole 14 Spline shaft part 15 Energizing Mechanism 16 Torque transmission joint 17 Intermediate transmission member 18 End transmission member 19 Intermediate uneven part 20 Concave part 21 Convex part 22, 22a-22d Circumferential spring part 23 End concavity and convex part 24 Concave part 25 Convex part 26 Ridge part 27, 27a Diameter Direction spring

Claims (7)

An intermediate transmission member having an intermediate concavo-convex portion formed by alternately arranging concave portions and convex portions with respect to the circumferential direction on one radial side portion;
One each disposed on both sides in the axial direction of the intermediate transmission member, each having an end irregularity formed by alternately arranging concave portions and convex portions in the circumferential direction on each other radial side, and each A pair of end portion transmitting members that engage the convex portion constituting the end concave and convex portion with the concave portion constituting the intermediate concave and convex portion,
A circumferential spring portion provided integrally with the intermediate transmission member between a circumferential side surface of the convex portion constituting the intermediate uneven portion and a circumferential side surface of the convex portion constituting the end uneven portion, These two circumferential side surfaces are urged in a direction away from each other in the circumferential direction, and are arranged in a state capable of bending deformation in the circumferential direction.
Joint for torque transmission. The circumferential spring portion is configured in a cantilevered leaf spring shape in which only one end portion in the radial direction is coupled to the intermediate transmission member.
The joint for torque transmission according to claim 1. The circumferential spring portion is configured in an arched leaf spring shape in which only both radial end portions are coupled to the intermediate transmission member.
The joint for torque transmission according to claim 1. A radial spring portion integrally provided with the intermediate transmission member is provided between the bottom surface of the concave portion constituting the intermediate concave and convex portion and the other radial end surface of the convex portion constituting the end concave and convex portion. Urged in a direction to move away from each other in the radial direction, and arranged in a state capable of bending deformation in the radial direction,
The joint for torque transmission according to any one of claims 1 to 3. The radial spring portion is configured in a cantilevered leaf spring shape in which only one end portion in the circumferential direction is coupled to the intermediate transmission member.
The joint for torque transmission according to claim 4. The radial spring portion is configured in an arched leaf spring shape in which only circumferential end portions are coupled to the intermediate transmission member.
The joint for torque transmission according to claim 4. A housing;
A worm wheel rotatably supported with respect to the housing;
A worm having a worm shaft and worm teeth provided on an outer peripheral surface of the worm shaft, the worm being rotatably supported with respect to the housing in a state where the worm teeth are engaged with the worm wheel;
An electric motor having an output shaft for rotationally driving the worm;
A torque transmission joint that connects the output shaft of the electric motor and the worm shaft so as to enable torque transmission;
The torque transmission joint is the torque transmission joint according to any one of claims 1 to 6, wherein one end transmission member of the pair of end transmission members is the electric motor. And the other end transmission member of the pair of end transmission members is fixed or integrally molded to the base end of the worm shaft. Power steering device.

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