Torque transmission joint, method of assembling same, and electric motor with worm reducer

Abstract

Provided is a torque transmission joint capable of smoothly transmitting torque between a pair of rotating members even if the central axes of the pair of rotating members are not aligned with each other, and capable of preventing the occurrence of abnormal noise between the pair of rotating members. A torque transmission joint (1) is provided with a first rotating member (2), a second rotating member (3), a coupling (4), a first elastic body (5), and a second elastic body (6). The coupling (4) has a first claw section (26) on at least one of the radially outer side and the radially inner side of the end of the first support section (19) on the other side in the axial direction, and a second claw section (29) on at least one of the radially outer side and the radially inner side of the end of the second support section (20) on the one side in the axial direction. The first claw section (26) engages with a first supported section (36) of the first elastic body (5) from the other side in the axial direction, and the second claw section (29) engages with a second supported section (43) of the second elastic body (6) from one side in the axial direction.

Description

Technical Field

[0001] The present invention relates to a torque transmission joint that is assembled in various mechanical devices and is used to transmit torque between a pair of rotating members, and an electric motor with a worm reducer including the torque transmission joint. Background Art

[0002] In an electric power steering system, auxiliary power from an electric motor is applied to a steering rotation shaft that rotates in response to an operation of a steering wheel via a worm gear reducer.

[0003] There is an inevitable backlash in the meshing portion between the worm wheel and the worm that constitute the worm reducer. Therefore, there is a problem that a rattling sound is easily generated when the rotation direction of the worm changes.

[0004] Japanese Patent Application Laid-Open No. 2004-306898 describes a structure in which a spring-loaded biasing member is positioned between the housing and the bearing located at the worm's tip, one of a pair of bearings that rotatably supports the worm relative to the housing. This biasing member biases the worm's tip toward the worm wheel. This structure reduces backlash in the meshing area and prevents rattling noise from occurring in the meshing area between the worm wheel and worm.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2004-306898 Summary of the Invention

[0008] Technical problem that the invention aims to solve

[0009] In the conventional structure described in Japanese Patent Application Laid-Open No. 2004-306898, a splined shaft portion provided at the distal end of the output shaft of the electric motor is spline-engaged with a splined hole provided at the proximal end of the worm, thereby connecting the output shaft and the worm in a torque-transmittable manner. If the splined shaft portion and the splined hole are spline-engaged with no clearance in the circumferential direction, i.e., no backlash, no abnormal noise is generated at the splined engagement portion between the output shaft and the worm.

[0010] However, in this conventional structure, the worm needs to be swung to bias the tip of the worm toward the worm wheel using the biasing member, so the backlash of the spline engagement portion cannot be completely eliminated. Therefore, there is room for improvement in order to suppress the generation of abnormal noise.

[0011] An object of the present invention is to provide a torque transmission joint and an assembly method thereof, and an electric motor with a worm reducer equipped with the torque transmission joint, which can smoothly transmit torque between the pair of rotating parts even if the central axes of the pair of rotating parts are inconsistent with each other and can prevent abnormal noise from being generated between the pair of rotating parts.

[0012] Technical means to solve the problem

[0013] A torque transmission joint according to one aspect of the present invention includes a first rotating member, a second rotating member, a coupling, a first elastic body, and a second elastic body.

[0014] The first rotating member has first protrusions protruding toward one side in the axial direction at a plurality of locations in the circumferential direction of a side surface on one side in the axial direction.

[0015] The second rotating member has second protrusions protruding toward the other axial side at a plurality of locations in the circumferential direction of the side surface on the other axial side.

[0016] The coupling has:

[0017] First recesses, the first recesses being arranged at a plurality of locations in the circumferential direction, having a circumferential width greater than that of the first protrusion, and opening toward the other axial side for inserting the first protrusion through the opening;

[0018] Second recesses, the second recesses being arranged at a plurality of locations in the circumferential direction, having a circumferential width greater than that of the second convex portion, and opening toward one axial side for inserting the second convex portion therethrough;

[0019] first supporting portions that protrude toward the other axial side from a plurality of circumferential locations of the end portion on the other axial side and are respectively disposed between a pair of circumferentially adjacent first protrusions of the first protrusions; and

[0020] The second support portion protrudes toward the one side in the axial direction from a plurality of circumferential locations of the end portion on the one side in the axial direction and is respectively arranged between a pair of second protrusions adjacent to each other in the circumferential direction among the second protrusions.

[0021] The first elastic body includes: an annular first supported portion, which is arranged at multiple positions in the circumferential direction and is embedded in the first convex portion; and multiple first connecting portions, which respectively connect the radial outer end portions or radial inner end portions of a pair of first supported portions adjacent to each other in the circumferential direction in the first supported portion in the circumferential direction, and the portion of the first supported portion located between the first convex portion and the first supporting portion adjacent to each other in the circumferential direction, i.e., the first elastic sheet, is clamped between the first convex portion and the first supporting portion in the circumferential direction.

[0022] The second elastic body includes: an annular second supported portion, which is arranged at multiple positions in the circumferential direction and is embedded in the second convex portion; and multiple second connecting portions, which respectively connect the radial outer end portions or radial inner end portions of a pair of second supported portions adjacent to each other in the circumferential direction in the second supported portion in the circumferential direction, and the portion of the second supported portion located between the second convex portion and the second supporting portion adjacent to each other in the circumferential direction, i.e., the second elastic sheet, is clamped between the second convex portion and the second supporting portion in the circumferential direction.

[0023] In a torque transmission joint according to one embodiment of the present invention, the coupling includes a first claw portion that projects radially from at least one of a radially outer side and a radially inner side of an end portion on the other axial side of the first support portion; and a second claw portion that projects radially from at least one of a radially outer side and a radially inner side of an end portion on one axial side of the second support portion. The first claw portion engages with the first supported portion from the other axial side, and the second claw portion engages with the second supported portion from the one axial side.

[0024] In the torque transmission joint according to one aspect of the present invention, in the shaft coupling, the second recessed portions are respectively arranged at a plurality of locations in the circumferential direction between a pair of circumferentially adjacent first recessed portions in the first recessed portions.

[0025] The coupling comprises: a plurality of arm portions, each of which separates the first recess and the second recess adjacent to each other in the circumferential direction; a plurality of first side plate portions, each of which connects the end portions on one axial side of a pair of arm portions on both sides of the circumferential direction of the first recess among the plurality of arm portions in the circumferential direction; and a plurality of second side plate portions, each of which connects the end portions on the other axial side of a pair of arm portions on both sides of the circumferential direction of the second recess among the plurality of arm portions in the circumferential direction.

[0026] The first support portion protrudes from the side surface of the second side plate portions on the other axial side toward the other axial side, and the second support portion protrudes from the side surface of the first side plate portions on one axial side toward the one axial side.

[0027] In the torque transmission joint according to one aspect of the present invention, the side surface on the other axial side of the first claw portion and the side surface on one axial side of the second claw portion are formed by inclined guide surfaces inclined in a direction in which the axial width decreases as the axial width increases toward the distal end in the radial direction.

[0028] In the torque transmission joint of one embodiment of the present invention, the first claw portion is provided both radially outward and radially inward of the other axial end portion of the first support portion. The second claw portion is provided both radially outward and radially inward of the one axial end portion of the second support portion.

[0029] The plurality of first connecting portions circumferentially connect the radially outer end portions of a pair of first supported portions, and the circumferential length of the radially outer first claw portion is greater than the circumferential length of the radially inner first claw portion. The plurality of second connecting portions circumferentially connect the radially outer end portions of a pair of second supported portions, and the circumferential length of the radially outer second claw portion is greater than the circumferential length of the radially inner second claw portion.

[0030] In a torque transmission joint according to one embodiment of the present invention, the first elastic piece includes a first elastic protrusion on a radial portion of a circumferential side surface that faces the circumferential outer surface of the first protrusion. The first elastic protrusion protrudes circumferentially and abuts the circumferential outer surface of the first protrusion with an interference fit. The second elastic piece includes a second elastic protrusion on a radial portion of a circumferential side surface that faces the circumferential outer surface of the second protrusion. The second elastic protrusion protrudes circumferentially and abuts the circumferential outer surface of the second protrusion with an interference fit.

[0031] In a torque transmission joint according to one embodiment of the present invention, the first elastic body has a first chamfered portion at a connection between a side surface on the other axial side of the first elastic piece and a circumferential side surface of the first elastic piece that faces the circumferential outer side of the first protrusion. The second elastic body has a second chamfered portion at a connection between a side surface on one axial side of the second elastic piece and a circumferential side surface of the second elastic piece that faces the circumferential outer side of the second protrusion.

[0032] In a torque transmission joint of one embodiment of the present invention, the first rotating component has a first base, the first convex portion protrudes toward one axial side from multiple circumferential positions of the side surface on one axial side of the first base, and the first rotating component has first corner portions at the connection portions between the side surfaces on both sides of the circumferential direction of the first convex portion and the side surface on one axial side of the first base, and the first corner portions are inclined in a direction toward a side away from the central portion of the first convex portion in the circumferential direction as they move toward the other axial side.

[0033] The second rotating component has a second base, the second convex portion protrudes toward the other axial side from multiple circumferential positions of the side surface of the second base on the other axial side, and the second rotating component has second corner portions at the connection portions between the side surfaces on both sides of the circumferential direction of the second convex portion and the side surface of the second base on the other axial side, and the second corner portions are inclined in a direction toward a side away from the central portion of the second convex portion in the circumferential direction as they go toward the one axial side.

[0034] In a torque transmission joint according to one embodiment of the present invention, the axial width of the first chamfered portion is greater than or equal to the axial width of the first corner portion, and the circumferential width of the first chamfered portion is greater than or equal to the circumferential width of the first corner portion. The axial width of the second chamfered portion is greater than or equal to the axial width of the second corner portion, and the circumferential width of the second chamfered portion is greater than or equal to the circumferential width of the second corner portion.

[0035] In a torque transmission joint of one embodiment of the present invention, the radially inner portion of the side surface on the other axial side of the first support portion is composed of a first flat surface that is orthogonal to the axial direction of the coupling, and the radially outer portion of the side surface on the other axial side of the first support portion is composed of a first inclined surface that is inclined in a direction toward one axial side as it moves toward the radial outer side.

[0036] The radially inner portion of the side surface on one axial side of the second support portion is composed of a second flat surface orthogonal to the axial direction of the coupling, and the radially outer portion of the side surface on the other axial side of the second support portion is composed of a second inclined surface that is inclined in a direction toward the other axial side as it moves radially outward.

[0037] The present invention can be implemented by appropriately combining the structures of the torque transmission joints of the above-mentioned various aspects within a range where no contradiction occurs.

[0038] A method for assembling a torque transmission joint according to one aspect of the present invention comprises:

[0039] a step of assembling the first elastic body to the other axial side portion of the coupling in a state where the second flat surface of the second support portion of the coupling is in contact with the upper surface of the support base; and

[0040] A step of assembling the second elastic body to one axial side portion of the shaft coupling in a state in which the first flat surface constituting the first support portion of the shaft coupling is in contact with an upper surface of a support base.

[0041] An electric motor with a worm reducer according to one embodiment of the present invention includes:

[0042] an electric motor having an output shaft;

[0043] A worm reducer comprising: a worm wheel having gear teeth on an outer peripheral surface; and a worm having worm teeth on an outer peripheral surface meshing with the gear teeth; and

[0044] A torque transmission joint connects the output shaft and the worm in a torque-transmittable manner.

[0045] The torque transmission joint is a torque transmission joint according to one embodiment of the present invention. The first rotating member is fixed to the output shaft or integrally formed with the output shaft. The second rotating member is fixed to the worm or integrally formed with the worm.

[0046] Effects of the Invention

[0047] According to one embodiment of the present invention, there is provided a torque transmission joint and an assembly method thereof, and an electric motor with a worm reducer having the torque transmission joint, which can smoothly transmit torque between the pair of rotating parts even when the center axes of the pair of rotating parts are not aligned with each other and can prevent abnormal noise from being generated between the pair of rotating parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a partially cutaway side view showing an electric power steering system including a torque transmission joint according to a first example of an embodiment of the present invention.

[0049] Figure 2 yes Figure 1 AA cross-sectional view.

[0050] Figure 3 It is a side view of the torque transmission joint of the first example.

[0051] Figure 4 yes Figure 3 BB cross-sectional view.

[0052] Figure 5 yes Figure 3 CC cross-sectional view.

[0053] Figure 6 This is a perspective view showing a portion of the torque transmission joint of the first example in an exploded manner.

[0054] Figure 7 (A) is a side view showing an assembly of a coupling, a first elastic body, and a second elastic body constituting the torque transmission joint of the first example. Figure 7 (B) is from Figure 7 The end view of the assembly is viewed from the right side of (A).

[0055] Figure 8 yes Figure 7 (B) DD cross-sectional view.

[0056] Figure 9 Part of the image is omitted. Figure 8 Magnified image of the upper right part.

[0057] Figure 10 This is a perspective view showing an exploded view of the assembly of the first example.

[0058] Figure 11 (A) is an end view showing the first rotating member of the first example, Figure 11 (B) is from Figure 11 (A) is a side view of the first rotating component viewed from the right side, Figure 11 (C) is Figure 11 EE cross-sectional view of (A).

[0059] Figure 12 (A) is an end view showing the second rotating member of the first example, Figure 12 (B) is from Figure 12 (A) is a side view of the second rotating member viewed from the left side, Figure 12 (C) is Figure 12 FF cross-sectional view of (A).

[0060] Figure 13 (A) is a side view showing a coupling of the first example, Figure 13 (B) is from Figure 13 Observe the end view of the coupling from the right side of (A). Figure 13 (C) is Figure 13 (B) GG cross-sectional view.

[0061] Figure 14 (A) is a side view of the elastic body of the first example, Figure 14 (B) is from Figure 14 The end view of the elastic body is observed on the right side of (A).

[0062] Figure 15 (A) is Figure 14 (B) HH cross-sectional view, Figure 15 (B) is Figure 14 (B) II sectional view.

[0063] Figure 16 (A)~ Figure 16 (C) is a side view showing the assembling operation of the above-mentioned assembly of the first example in order of steps.

[0064] Figure 17 This is a view showing a portion of the circumference of an assembly of a coupling, a first elastic body, and a second elastic body constituting a torque transmission joint according to a second example of an embodiment of the present invention, as viewed from the axial direction.

[0065] Figure 18 yes Figure 17 Stereoscopic image.

[0066] Figure 19 yes Figure 17 JJ cross-sectional view.

[0067] Figure 20 (A) and Figure 20 (B) is about the first rotating member of the second example, which is equivalent to Figure 11 (A) and Figure 11 Figure (B).

[0068] Figure 21 (A) and Figure 21 (B) is about the second rotating member of the second example, which is equivalent to Figure 12 (A) and Figure 12 Figure (B). DETAILED DESCRIPTION

[0069] [First example]

[0070] use Figures 1 to 16 A first example of an embodiment of the present invention will be described.

[0071] (1) Torque transmission joint

[0072] The torque transmission joint of the present invention can be incorporated into various mechanical devices and applied as a torque transmission joint for smoothly transmitting torque between a pair of rotating components. In this example, the application of the torque transmission joint of the present invention to a torque transmission joint incorporated into an electric assist device constituting an electric power steering system will be described.

[0073] In the following description of the torque transmission joint 1 of this example, one axial side is Figure 2 、 Figure 3 、 Figure 6 、 Figure 7 A and Figure 8 The left side of the axis is the right side of these figures, and the other side is the right side of these figures.

[0074] The torque transmission joint 1 of this example includes a first rotating member 2 , a second rotating member 3 , a coupling 4 , a first elastic body 5 , and a second elastic body 6 .

[0075] like Figure 6 and Figure 11 (A)~ Figure 11 As shown in FIG. 1 (C), the first rotating member 2 has first protrusions 7 protruding toward the other axial side at a plurality of locations in the circumferential direction of the side surface on one axial side.

[0076] In this example, the first rotating component 2 has a first base portion 8 in the form of an annular plate. The first protrusion 7 protrudes toward one side in the axial direction at a plurality of locations (four locations in the example shown) spaced evenly in the circumferential direction from the radially outer end of the side surface on one axial side of the first base portion 8. The first protrusion 7 has an end face shape that is fan-shaped when viewed from the axial direction. The first rotating component 2 has a cylindrical protrusion 9 that protrudes from the radially inner end of the side surface on one axial side of the first base portion 8 over the entire circumference toward the other axial side. The protrusion 9 is a portion for ensuring the axial length of the center hole of the first rotating component 2.

[0077] The first rotating member 2 is made of a material having higher rigidity than that of the first elastic body 5 , that is, a material that is less likely to be elastically deformed, such as synthetic resin, metal (including sintered metal), or the like.

[0078] The first rotating member 2 is externally fixed to one of a pair of rotating members to be connected to each other (in this example, the output shaft 64 of the electric motor 62 (see FIG. 1 )) in a torque-transmittable manner. Figure 2 ))'s end.

[0079] like Figure 6 and Figure 12 (A)~ Figure 12 As shown in FIG. 5 (C), the second rotating member 3 has second protrusions 10 protruding toward one axial side at a plurality of locations in the circumferential direction of the side surface on the other axial side.

[0080] In this example, the second rotating component 3 has a second base 12 in the form of an annular plate. The second protrusion 10 protrudes toward the other axial side at a plurality of locations (four locations in the illustrated example) at equal intervals in the circumferential direction from the radially outer end of the side surface on the other axial side of the second base 12. The second protrusion 10 has an end face shape that is fan-shaped when viewed from the axial direction. The second rotating component 3 has: a cylindrical protrusion 11 that protrudes from the radially inner half of the side surface on one axial side of the second base 12 toward the one axial side throughout the entire circumference, and a cylindrical protrusion 13 that protrudes from the radially inner end of the side surface on the other axial side of the second base 12 toward the other axial side throughout the entire circumference. The protrusions 11 and 13 are portions for ensuring the axial length of the center hole of the second rotating component 3.

[0081] The second rotating member 3 is made of a material having higher rigidity than the second elastic body 6, such as synthetic resin or metal (including sintered metal). The second rotating member 3 may be made of the same material as the first rotating member 2 or a different material.

[0082] The second rotating member 3 is externally fixed to the other rotating member (in this example, the worm 67 (see FIG. 1 )) of a pair of rotating members to be connected to each other in a torque-transmitting manner. Figure 2 ))'s end.

[0083] like Figure 4 、 Figure 10 and Figure 13 (A)~ Figure 13 As shown in FIG. 5 (C), the coupling 4 includes a first recessed portion 14, a second recessed portion 15, a first support portion 19, and a second support portion 20, each of which is provided in plural numbers.

[0084] The first recesses 14 are arranged at multiple locations (four locations in the illustrated example) circumferentially of the coupling 4. They have a circumferential width greater than that of the first protrusion 7 and are open axially to the other side. These openings allow the first protrusion 7 to be inserted through these openings. In this example, the first recesses 14 are open not only axially to the other side but also radially outward.

[0085] The second recesses 15 are arranged at multiple locations (four locations in the illustrated example) circumferentially. They have a circumferential width greater than that of the second protrusion 10 and are open axially to one side, allowing the second protrusion 10 to be inserted through this opening. In this example, the second recesses 15 are open not only axially to one side but also radially outward. In this example, the second recesses 15 are arranged at multiple circumferential locations between a pair of circumferentially adjacent first recesses 14.

[0086] In this example, the coupling 4 further includes a plurality of arm portions 16. The arm portion 16 is a portion that partitions the first recessed portion 14 and the second recessed portion 15 that are adjacent to each other in the circumferential direction.

[0087] In this example, the arms 16 are rectangular plates and arranged radially about the central axis of the coupling 4. In this example, the coupling 4 also includes a cylindrical boss 21 at its radial center. The arms 16 protrude radially outward from multiple locations along the outer circumference of the boss 21. The radially inner sides of the first and second recesses 14, 15 are not open but instead are blocked by the boss 21.

[0088] In this example, the coupling 4 further includes a plurality of first side plates 17. The first side plates 17 are portions that connect one axial end portion of a pair of arm portions 16 located on both circumferential sides of the first recess 14 in the circumferential direction.

[0089] In this example, the first side plate portion 17 has a fan-shaped end face when viewed from the axial direction. The radially inner end of the first side plate portion 17 is connected to the outer peripheral surface of the axial end of the boss portion 21. The axial end of the first recess 14 is not open but is blocked by the first side plate portion 17.

[0090] In this example, the coupling 4 further includes a plurality of second side plates 18. The second side plates 18 are portions that circumferentially connect the other axial ends of the pair of arm portions 16 located on both circumferential sides of the second recess 15.

[0091] In this example, the second side plate portion 18 has a fan-shaped end face when viewed from the axial direction. The radially inner end of the second side plate portion 18 is connected to the outer peripheral surface of the other axial end of the boss portion 21. The other axial side of the second recess 15 is not open but is blocked by the second side plate portion 18.

[0092] In this example, each first recess 14 is defined by the outer peripheral surface of the boss portion 21, the side surface on the other axial side of the first side plate portion 17, and the mutually opposing circumferential side surfaces of the pair of arm portions 16 circumferentially connected by the first side plate portion 17. The first protrusion 7 of the first rotating member 2 is inserted into the first recess 14 through the opening on the other axial side.

[0093] Here, the first recesses 14 have a circumferential width greater than that of the first protrusions 7. Therefore, the first protrusions 7 of the first rotating member 2 are inserted into each of the first recesses 14 so as to be relatively displaceable in the circumferential direction. Specifically, when the first protrusions 7 are positioned inside the first recesses 14, a circumferential gap exists between at least one of the circumferentially opposite inner surfaces of the first recesses 14 and the circumferentially opposite outer surfaces of the first protrusions 7. Furthermore, a radial gap exists between the radially inner surface of the first protrusion 7 and the outer circumferential surface of the boss portion 21.

[0094] In this example, each second recess 15 is defined by the outer peripheral surface of the boss portion 21, the axial side surface of the second side plate portion 18, and the mutually opposing circumferential side surfaces of the pair of arm portions 16 connected circumferentially by the second side plate portion 18. The second protrusion 10 of the second rotating member 3 is inserted into the second recess 15 through the axial opening.

[0095] Here, the second recesses 15 have a circumferential width greater than that of the second protrusions 10. Therefore, the second protrusions 10 of the second rotating member 3 are inserted into each second recess 15 so as to be relatively displaceable in the circumferential direction. Specifically, when the second protrusions 10 are positioned inside the second recesses 15, a circumferential gap exists between at least one of the circumferentially opposite inner side surfaces of the second recess 15 and the circumferentially opposite outer side surfaces of the second protrusion 10. Furthermore, a radial gap exists between the radially inner side surface of the second protrusion 10 and the outer circumferential surface of the boss portion 21.

[0096] In other words, the first protrusions 7 of the first rotating member 2 and the second protrusions 10 of the second rotating member 3 are alternately arranged in the circumferential direction, and the arm portion 16 of the coupling 4 is arranged to be displaceable in the circumferential direction between the first protrusions 7 and the second protrusions 10 adjacent to each other in the circumferential direction.

[0097] When implementing the structure of the present invention, instead of providing the boss portion 21 in the radial center portion of the coupling 4, a cylindrical portion may be provided in the radial outer portion, i.e., the outer peripheral portion, of the coupling, and the radial outer end portions of the arm portion 16, the first side plate portion 17, and the second side plate portion 18 may be connected to the inner peripheral surface of the cylindrical portion.

[0098] In this case, the first recessed portion is defined by the inner circumferential surface of the cylindrical portion, the side surface on the other axial side of the first side plate portion 17, and the circumferentially opposed side surfaces of the pair of arm portions 16 circumferentially connected by the first side plate portion 17. Furthermore, the second recessed portion is defined by the inner circumferential surface of the cylindrical portion, the side surface on one axial side of the second side plate portion 18, and the circumferentially opposed side surfaces of the pair of arm portions 16 circumferentially connected by the second side plate portion 18. Furthermore, a radial gap exists between the radially outer side surfaces of each of the first and second protrusions 7 and 10 and the inner circumferential surface of the cylindrical portion.

[0099] Furthermore, when implementing the structure of the present invention, the boss portion 21 and the cylindrical portion may be omitted if sufficient rigidity of the coupling can be ensured.

[0100] In addition, in the structure of this example, the plurality of first recesses and the plurality of second recesses are arranged at different circumferential positions in the coupling. However, when implementing the structure of the present invention, the plurality of first recesses and the plurality of second recesses can also be arranged at the same circumferential position. In this case, the plurality of first recesses are arranged in the axially opposite side portion of the coupling, and the plurality of second recesses are arranged in the axially opposite side portion.

[0101] The first support portion 19 is a portion for supporting the first elastic body 5. The first support portion 19 protrudes toward the other axial side from multiple locations in the circumferential direction of the end portion on the other axial side of the coupling 4. In this example, the first support portion 19 protrudes toward the other axial side from the side surface on the other axial side of the second side plate portion 18.

[0102] In this example, each first support portion 19 has a sector-shaped end surface when viewed from the axial direction. In this example, the radially inner portion of the side surface on the other axial side of the first support portion 19 is formed by a first flat surface 22 perpendicular to the axial direction of the coupling 4, while the radially outer portion of the side surface on the other axial side of the first support portion 19 is formed by a first inclined surface 23 that tilts axially toward one side as it moves radially outward. The radially outer end of the first flat surface 22 is connected to the radially inner end of the first inclined surface 23.

[0103] The first inclined surface 23 is provided so that when the central axis of the first rotating component 2 is tilted relative to the central axis of the coupling 4 during use, the radially outer portion of the side surface on the other axial side of the first support portion 19 (the first inclined surface 23) is not easily interfered with the side surface on the axial side of the first rotating component 2, specifically, the side surface on the axial side of the first base 8.

[0104] The second support portion 20 is a portion for supporting the second elastic body 6. The second support portion 20 protrudes axially from multiple locations in the circumferential direction of the axial end portion of the coupling 4. In this example, the second support portion 20 protrudes axially from the axial side surface of the first side plate portion 17.

[0105] In this example, each second support portion 20 has a sector-shaped end face when viewed in the axial direction. In this example, the radially inner portion of the side surface on one axial side of the second support portion 20 is formed by a second flat surface 24 perpendicular to the axial direction of the coupling 4, and the radially outer portion of the side surface on the other axial side of the second support portion 20 is formed by a second inclined surface 25 that inclines toward the other axial side as it moves radially outward.

[0106] The second inclined surface 25 is provided so that when the center axis of the second rotating component 3 is tilted relative to the center axis of the coupling 4 during use, the radially outer portion of the side surface on the axial side of the second support portion 20 (the second inclined surface 25) is not easily interfered with the side surface on the other axial side of the second rotating component 3, specifically the side surface on the other axial side of the second base 12.

[0107] The inclination angle α of each of the first inclined surface 23 and the second inclined surface 25 with respect to a virtual plane perpendicular to the central axis of the coupling 4 can be set arbitrarily, but is preferably set to 1° to 10°.

[0108] The coupling 4 includes a first claw portion 26 that projects radially from at least one of the radially outer side and the radially inner side of the end portion on the other axial side of the first support portion 19, and a second claw portion 29 that projects radially from at least one of the radially outer side and the radially inner side of the end portion on one axial side of the second support portion 20. In this example, the coupling 4 includes the first claw portion 26 that projects radially from both the radially outer side and the radially inner side of the end portion on the other axial side of the first support portion 19, and includes the second claw portion 29 that projects radially from both the radially outer side and the radially inner side of the end portion on one axial side of the second support portion 20.

[0109] The first claw portion 26 is a portion for preventing the first elastic body 5 from axially falling off from the first support portion 19 . The second claw portion 29 is a portion for preventing the second elastic body 6 from axially falling off from the second support portion 20 .

[0110] Furthermore, when implementing the structure of the present invention, when the first claw portion 26 is provided only on at least one of the radially outer side and the radially inner side of the first support portion, and when the second claw portion 29 is provided only on at least one of the radially outer side and the radially inner side of the second support portion, it is preferable to provide only the first claw portion 26 or the second claw portion 29 on the radially outer side. The reason for this is that providing the first claw portion 26 or the second claw portion 29 on the radially outer side makes it easier to manufacture the first claw portion 26 or the second claw portion 29 than on the radially inner side. In addition, the circumferential length of the first claw portion 26 or the second claw portion 29 can be increased, thereby making it easier to ensure the rigidity of the coupling and to prevent the first elastic body 5 or the second elastic body 6 from falling out.

[0111] In this example, the first claw portion 26 is composed of a radially outer first outer claw portion 27 and a radially inner first inner claw portion 28. The first outer claw portion 27 projects radially outward from a circumferentially intermediate portion of the radially outer side surface of the other axial end portion of the first support portion 19. The first inner claw portion 28 projects radially inward from a circumferentially intermediate portion of the radially inner side surface of the other axial end portion of the first support portion 19. The circumferential length relationship between the first outer claw portion 27 and the first inner claw portion 28 can be arbitrarily determined; however, in this example, the circumferential length of the first outer claw portion 27 is greater than the circumferential length of the first inner claw portion 28.

[0112] In this example, a through hole 85 is formed in the portion of the second side plate portion 18 that axially overlaps with the first inner claw portion 28. The through hole 85 is formed as a passage for the mold component for molding the axially one side surface of the first inner claw portion 28, among the multiple mold components used in manufacturing the coupling 4 by injection molding, to be pulled out axially when the mold is opened.

[0113] In this example, the second claw portion 29 is composed of a radially outer second claw portion 30 and a radially inner second claw portion 31. The second outer claw portion 30 projects radially outward from a circumferentially intermediate portion of the radially outer side surface of the axially one end portion of the second support portion 20. The second inner claw portion 31 projects radially inward from a circumferentially intermediate portion of the radially inner side surface of the axially one end portion of the second support portion 20. The circumferential length relationship between the second outer claw portion 30 and the second inner claw portion 31 can be arbitrarily determined; however, in this example, the circumferential length of the second outer claw portion 30 is greater than the circumferential length of the second inner claw portion 31.

[0114] In this example, a through hole 86 is formed in the portion of the first side plate portion 17 that axially overlaps with the second inner claw portion 31. The through hole 86 is formed as a passage for the mold component for molding the side surface on the other axial side of the second inner claw portion 31, among the multiple mold components used in manufacturing the coupling 4 by injection molding, to be pulled out toward the other axial side during mold opening.

[0115] In this example, the side surfaces on the other axial side of the first outer claw portion 27 and the first inner claw portion 28 constituting the first claw portion 26, and the side surfaces on one axial side of the second outer claw portion 30 and the second inner claw portion 31 constituting the second claw portion 29 are respectively composed of inclined guide surfaces 32, 33, 34, and 35, and the inclined guide surfaces 32, 33, 34, and 35 are inclined in the direction in which the axial width of the claw portion decreases as it radially approaches the top end side.

[0116] Specifically, the first outer inclined guide surface 32, which constitutes the side surface on the other axial side of the first outer claw portion 27, is inclined in an axially oriented direction as it moves radially outward. The first inner inclined guide surface 33, which constitutes the side surface on the other axial side of the first inner claw portion 28, is inclined in an axially oriented direction as it moves radially inward. The first outer inclined guide surface 32 and the first inner inclined guide surface 33 function as guide surfaces when assembling the first elastic body 5 to the first support portion 19.

[0117] The second outer inclined guide surface 34, which constitutes the axially one side surface of the second outer claw portion 30, is inclined toward the other axial side as it moves radially outward. The second inner inclined guide surface 35, which constitutes the axially one side surface of the second inner claw portion 31, is inclined toward the other axial side as it moves radially inward. The second outer inclined guide surface 34 and the second inner inclined guide surface 35 function as guide surfaces when assembling the second elastic body 6 to the second support portion 20.

[0118] The inclination angle β of the inclined guide surfaces 32, 33, 34, and 35 relative to the imaginary plane perpendicular to the axial direction of the coupling 4 can be set arbitrarily, but is preferably set to 15 to 60 degrees. In this example, the inclination angle β is larger than the inclination angle α (β>α).

[0119] In this example, the axially one side surface of the first outer claw portion 27 and the first inner claw portion 28 and the axially other side surface of the second outer claw portion 30 and the second inner claw portion 31 are formed of flat surfaces orthogonal to the axial direction of the coupling 4 .

[0120] The coupling 4 is made of a material that is more rigid than the material constituting the first elastic body 5 and the second elastic body 6, and that minimizes the impact of contact with the first protrusion 7 of the first rotating member 2 and the second protrusion 10 of the second rotating member 3. Specifically, the coupling 4 can be made of a resin such as polyphenylene sulfide (PPS), polyetheretherketone (PEEK), or nylon; a resin obtained by mixing reinforcing fibers into these resins; an elastomer such as rubber; or a belt material obtained by reinforcing rubber with woven fabric.

[0121] like Figure 14 (A) Figure 14 (B) Figure 15 (A) and Figure 15 As shown in (B), the first elastic body 5 includes: an annular first supported portion 36, which is arranged at multiple locations in the circumferential direction (four locations in the illustrated example); and a plurality of first connecting portions 37, which connect the radially outer end portions or radially inner end portions (in this example, the radially outer end portions) of a pair of circumferentially adjacent first supported portions 36 in the circumferential direction. The first supported portion 36 is externally fitted to the first protrusion 7 of the first rotating member 2. The portion of the first supported portion 36 located between the circumferentially adjacent first protrusion 7 and the first supporting portion 19, namely the first elastic piece 38, is circumferentially clamped between the first protrusion 7 and the first supporting portion 19.

[0122] In this example, each of the first elastic pieces 38 is configured in a rectangular column shape, and the first elastic pieces 38 are arranged along the radial direction.

[0123] The first supported portion 36 constituting the first elastic body 5 is composed of a pair of circumferentially adjacent first elastic pieces 38, a first outer engaging piece 39, and a first inner engaging piece 40. The first outer engaging piece 39 circumferentially connects the radially outer ends of the pair of first elastic pieces 38. The first inner engaging piece 40 circumferentially connects the radially inner ends of the pair of first elastic pieces 38. The first outer engaging piece 39 and the first inner engaging piece 40 both have arcuate end faces when viewed from the axial direction. The first supported portion 36 can be externally fitted to the first protrusion 7 of the first rotating member 2 without circumferential or radial play.

[0124] The plurality of first connecting portions 37 constituting the first elastic body 5 are arranged at positions offset in the circumferential direction from the first outer engaging piece 39, and circumferentially connect the radially outer end portions of a pair of circumferentially adjacent first elastic pieces 38. Each first connecting portion 37 has an end surface shape that is arcuate when viewed from the axial direction. The first connecting portions 37 and the first outer engaging piece 39 are alternately arranged in the circumferential direction to form a circular ring shape as a whole. When implementing the structure of the present invention, it is also possible to connect the radially inner end portions of a pair of circumferentially adjacent first elastic pieces 38 in the circumferential direction instead of using the first connecting portion to circumferentially connect the radially outer end portions of the pair of circumferentially adjacent first elastic pieces.

[0125] In this example, the axial thickness of the first outer engaging piece 39 is smaller than the axial thickness of the first elastic piece 38, the first inner engaging piece 40, and the first connecting portion 37. Specifically, the axial thickness of the first outer engaging piece 39 is approximately half the axial thickness of the first elastic piece 38, the first inner engaging piece 40, and the first connecting portion 37. The side surface on the axially opposite side of the first outer engaging piece 39 in the first elastic body 5 is located axially closer to the side surface on the axially opposite side of the remaining portion.

[0126] In this example, the first inner engaging piece 40 has a cutout 41 opened radially outward and toward the other axial side in a circumferentially intermediate portion of a half portion on the other axial side.

[0127] The surrounding portion of the first elastic body 5 disposed around the first protrusion 7, specifically the surrounding portion formed by the first connecting portion 37 and the pair of first elastic pieces 38 connected by the first connecting portion 37, comprises a first elastic flat surface 87 on the radially inner side of the side surface on the other axial side, which is perpendicular to the axial direction of the first elastic body 5. The radially outer side portion of the surrounding portion comprises a first elastic inclined surface 88 that inclines axially toward one side as it moves radially outward. The radially outer end of the first elastic flat surface 87 is connected to the radially inner end of the first elastic inclined surface 88. In this example, the inclination angle of the first elastic inclined surface 88 relative to the first elastic flat surface 87 is set to be approximately the same as the inclination angle of the first inclined surface 23 relative to the first flat surface 22.

[0128] The first elastic inclined surface 88 is provided so that when the central axis of the first rotating component 2 is tilted relative to the central axis of the first elastic body 5 during use, the radially outer portion of the side surface on the other axial side of the surrounding portion (the first elastic inclined surface 88) is not easily interfered with the side surface on the axial side of the first rotating component 2, specifically, the side surface on the axial side of the first base 8.

[0129] The circumferential width of a portion between the pair of first elastic pieces 38 connected in the circumferential direction by the first connecting portion 37 is smaller than the circumferential width of the first recessed portion 14 of the coupling 4 .

[0130] The first elastic piece 38 may include a first elastic protrusion 42 protruding in the circumferential direction on a portion of the radial direction of the circumferential side surface that faces the circumferential outer surface of the first protrusion 7. In this example, in order to ensure that the first elastic protrusion 42 is in stable contact with the circumferential outer surface of the first protrusion 7 even when the transmitted torque changes, the first elastic piece 38 includes the first elastic protrusion 42 protruding in the circumferential direction on a portion of the circumferential side surface that faces the circumferential outer surface of the first protrusion 7 that is radially inward of the central portion, more specifically, on a portion radially inward of the first elastic inclined surface 88.

[0131] In this case, the circumferential width of the portion between the top end surfaces of the pair of circumferentially opposing first elastic protrusions 42 corresponds to the circumferential width of the portion between the pair of first elastic pieces 38 circumferentially connected by the first connecting portion 37. In this example, the circumferential width of the portion radially offset from the first elastic protrusion 42 in the portion between the pair of first elastic pieces 38 circumferentially connected by the first connecting portion 37 is also smaller than the circumferential width of the first recess 14 of the coupling 4. The first elastic protrusion 42 has a convex arc shape when viewed from the axial direction.

[0132] When implementing the structure of the present invention, the shape and position of the first elastic protrusion 42 are not limited to the structure shown in the figure. For example, the shape of the first elastic protrusion as viewed from the axial direction may also be a triangle, a trapezoid, or other shapes. The number of first elastic protrusions is not limited to one and may also be multiple. The first elastic protrusion may also be omitted, and the entire circumferential side surface of the first elastic piece that faces the circumferential outer surface of the first protrusion may be formed entirely by a flat portion.

[0133] The first elastic body 5 is supported at the other axial end portion of the coupling 4 by fitting the annular first supported portion 36 onto the first supporting portion 19 without play in the circumferential and radial directions.

[0134] Furthermore, in this state, the first claw portion 26 engages with the first supported portion 36 from the other axial side. Specifically, the first outer claw portion 27 engages with the first outer engaging piece 39 constituting the first supported portion 36 from the other axial side. The first inner claw portion 28 enters the inside of the cutout 41 of the first inner engaging piece 40 and engages with the portion of the first inner engaging piece 40 adjacent to one axial side of the cutout 41 from the other axial side.

[0135] In the structure of this example, the first outer claw portion 27 and the first inner claw portion 28 are engaged with the first supported portion 36 from the other axial side, thereby effectively preventing the first supported portion 36 from escaping from the periphery of the first supporting portion 19 to the other axial side, that is, the first elastomer 5 from falling off axially from multiple first supporting portions 19.

[0136] In particular, in this example, the first elastic body 5 includes a plurality of first connecting portions 37 that circumferentially connect the radially outer end portions of a pair of circumferentially adjacent first supported portions 36. This configuration creates a circular ring shape with a continuous, fully circumferential shape, resulting in a higher rigidity than the radially inner end portion of the first elastic body 5. Furthermore, the first outer claw portion 27, which engages with the first outer engaging piece 39 forming the radially outer end portion from the axially opposite side, has a greater circumferential length than the first inner claw portion 28. Consequently, the engagement between the first outer engaging piece 39 and the first outer claw portion 27 more effectively prevents the first supported portion 36 from escaping axially from the periphery of the first supporting portion 19.

[0137] The first protrusion 7 of the first rotating member 2 is inserted between a pair of first elastic pieces 38 circumferentially connected by a first connecting portion 37 in the first elastic body 5. Specifically, the first elastic pieces 38 constituting the first elastic body 5 are circumferentially sandwiched between the first protrusion 7 and the first supporting portion 19. In this embodiment, the circumferential side surfaces of the circumferentially adjacent pair of first elastic pieces 38 abut with the pair of circumferential outer side surfaces of the first protrusion 7 with interference fit. This effectively prevents rattling of the first rotating member 2 relative to the coupling 4.

[0138] In particular, in this example, the first elastic piece 38 includes the first elastic protrusion 42 that abuts against the circumferential outer surface of the first convex portion 7 with interference, and thus can more effectively exhibit the effect of preventing rattling.

[0139] In addition, the radially outer side surface of the first protrusion 7 may or may not be in contact with the radially inner side surface of the first connection portion 37 .

[0140] like Figure 14 (A) Figure 14 (B) Figure 15 (A) and Figure 15 As shown in (B), the second elastic body 6 includes: an annular second supported portion 43 arranged at multiple locations in the circumferential direction (four locations in the illustrated example); and multiple second connecting portions 44, each connecting the radially outer end portions or radially inner end portions (in this example, the radially outer end portions) of a pair of circumferentially adjacent second supported portions 43 in the circumferential direction. The second supported portion 43 is externally fitted onto the second protrusion 10 of the second rotating member 3. The portion of the second supported portion 43 located between the circumferentially adjacent second protrusion 10 and the second supporting portion 20, namely the second elastic piece 45, is circumferentially sandwiched between the second protrusion 10 and the second supporting portion 20.

[0141] In this example, as the second elastic body 6 , an elastic body having the same specifications as the first elastic body 5 , that is, an elastic body having the same shape, size and material as the first elastic body 5 is used.

[0142] That is, the second supported portion 43 constituting the second elastic body 6 is composed of a pair of circumferentially adjacent second elastic pieces 45, a second outer engaging piece 46, and a second inner engaging piece 47. Instead of circumferentially connecting the radially outer ends of the pair of circumferentially adjacent second elastic pieces by the second connecting portion, the radially inner ends of the pair of second elastic pieces may be connected circumferentially.

[0143] The second inner engaging piece 47 has a cutout 48 opened radially outward and to one axial side in a circumferentially intermediate portion of a half portion on one axial side.

[0144] The surrounding portion of the second elastic body 6 arranged around the second protrusion 10, specifically, the radially inner portion of the side surface on the axial side of the surrounding portion composed of the second connecting portion 44 and a pair of second elastic sheets 45 connected by the second connecting portion 44 is composed of a second elastic flat surface 89 that is orthogonal to the axial direction of the second elastic body 6, and the radially outer portion of the side surface on the axial side of the surrounding portion is composed of a second elastic inclined surface 90 that is inclined in the direction toward the other axial side as it moves toward the radial outside.

[0145] The circumferential width of a portion between the pair of second elastic pieces 45 connected in the circumferential direction by the second connecting portion 44 is smaller than the circumferential width of the second recessed portion 15 of the coupling 4 .

[0146] The second elastic piece 45 has a second elastic protrusion 49 protruding in the circumferential direction on a radial portion of a circumferential side surface facing the circumferential outer surface of the second convex portion 10 .

[0147] The second elastic body 6 is the same as the first elastic body 5 in other respects.

[0148] The second elastic body 6 is supported at one axial end portion of the coupling 4 by fitting the annular second supported portion 43 onto the second supporting portion 20 without play in the circumferential and radial directions.

[0149] Furthermore, in this state, the second claw portion 29 engages with the second supported portion 43 from one axial side. Specifically, the second outer claw portion 30 engages with the second outer engaging piece 46 constituting the second supported portion 43 from one axial side. The second inner claw portion 31 enters the inner side of the cutout 48 of the second inner engaging piece 47 and engages with the portion of the second inner engaging piece 47 adjacent to the other axial side of the cutout 48 from one axial side.

[0150] In the structure of this example, the second outer claw portion 30 and the second inner claw portion 31 are engaged with the second supported portion 43 from one axial side, thereby effectively preventing the second supported portion 43 from escaping from the periphery of the second supporting portion 20 to one axial side, that is, the second elastic body 6 from falling off axially from multiple second supporting portions 20.

[0151] In particular, in this example, the plurality of second connecting portions 44 of the second elastic body 6 circumferentially connect the radially outer end portions of a pair of circumferentially adjacent second supported portions 43. This creates a circular ring shape with a continuous, fully circumferential shape, resulting in a higher rigidity than the radially inner end portion of the second elastic body 6. Furthermore, the circumferential length of the second outer claw portion 30, which engages axially with the second outer engaging piece 46 forming the radially outer end portion, is greater than the circumferential length of the second inner claw portion 31. Therefore, the engagement of the second outer engaging piece 46 with the second outer claw portion 30 more effectively prevents the second supported portion 43 from axially dislodging from the periphery of the second supporting portion 20.

[0152] The second protrusion 10 of the second rotating member 3 is inserted between a pair of second elastic pieces 45 circumferentially connected by a second connecting portion 44 in the second elastic body 6. Specifically, the second elastic pieces 45 constituting the second elastic body 6 are circumferentially sandwiched between the second protrusion 10 and the second supporting portion 20. In this embodiment, the circumferential side surfaces of the circumferentially adjacent pair of second elastic pieces 45 abut with an interference fit against the pair of circumferential outer side surfaces of the second protrusion 10. This effectively prevents rattling of the second rotating member 3 relative to the coupling 4.

[0153] In particular, in this example, the second elastic piece 45 includes the second elastic protrusion 49 that abuts against the circumferential outer surface of the second convex portion 10 with interference, and thus can more effectively exhibit the effect of preventing rattling.

[0154] In addition, the radially outer side surface of the second protrusion 10 may or may not be in contact with the radially inner side surface of the second connection portion 44 .

[0155] When the torque transmitted between a pair of rotating parts connected by the torque transmission joint 1 of this example, that is, a rotating part in which the first rotating part 2 is externally embedded and fixed at the axial end (in this example, the output shaft 64 of the electric motor 62) and another rotating part in which the second rotating part 3 is externally embedded and fixed at the axial end (in this example, the worm 67), is relatively small, as one rotating part rotates, the circumferential outer surface of the first protrusion 7 of the first rotating part 2 presses the circumferential outer surface of the first support part 19 of the coupling 4 in the circumferential direction via the first elastic piece 38 of the first elastic body 5.

[0156] As the coupling 4 rotates, the circumferential outer surface of the second support portion 20 of the coupling 4 presses against the circumferential outer surface of the second protrusion 10 of the second rotating member 3 via the second elastic piece 45 of the second elastic body 6. Thus, the rotational torque of one rotating member is transmitted to the other rotating member.

[0157] In contrast, if the torque transmitted between one rotating component and another rotating component increases, the first elastic piece 38 of the first elastic body 5 is elastically flattened in the circumferential direction between the circumferential outer surface of the first supporting portion 19 of the coupling 4 and the circumferential outer surface of the first protrusion 7 of the first rotating component 2, and the second elastic piece 45 of the second elastic body 6 is elastically flattened in the circumferential direction between the circumferential outer surface of the second supporting portion 20 of the coupling 4 and the circumferential outer surface of the second protrusion 10 of the second rotating component 3.

[0158] Moreover, the circumferential outer side surface of the first protrusion 7 of the first rotating part 2 directly abuts the circumferential inner side surface of the first recess 14 of the coupling 4, and the circumferential outer side surface of the second protrusion 10 of the second rotating part 3 directly abuts the circumferential inner side surface of the second recess 15 of the coupling 4.

[0159] The momentum of these abutments is weakened by the first elastic body 5 and the second elastic body 6, thereby preventing the generation of abnormal noises such as harsh teeth clicking sounds in the abutment parts between the circumferential outer surface of the first convex portion 7 and the circumferential inner surface of the first concave portion 14, and the abutment parts between the circumferential outer surface of the second convex portion 10 and the circumferential inner surface of the second concave portion 15.

[0160] In addition, in this state, most of the rotational torque of one rotating component is transmitted to the coupling 4 from the abutment portion between the circumferential outer surface of the first protrusion 7 and the circumferential inner surface of the first recess 14, and most of the torque transmitted to the coupling 4 is transmitted to the other rotating component from the abutment portion between the circumferential outer surface of the second protrusion 10 and the circumferential inner surface of the second recess 15.

[0161] In the torque transmission joint 1 of this example, even when the center axes of one rotating part and another rotating part are misaligned with each other, that is, when the center axes of one rotating part and another rotating part are not aligned with each other due to mutual inclination or eccentricity, the coupling 4 will cause the first elastic body 5 and / or the second elastic body 6 to elastically deform and tilt relative to the center axis of one rotating part and / or the center axis of the other rotating part, thereby enabling smooth torque transmission between one rotating part and another rotating part.

[0162] Furthermore, when implementing the structure of the present invention, it is also possible to make the rigidity of the first elastic body and the second elastic body different from each other, or to make the circumferential gap between the first protrusion and the first recess different from the circumferential gap between the second protrusion and the second recess different from each other. Thus, the magnitude of the transmission torque when the circumferential outer side surface of the first protrusion abuts the circumferential inner side surface of the first recess and the magnitude of the transmission torque when the circumferential outer side surface of the second protrusion abuts the circumferential inner side surface of the second recess can be made different. As a result, the torque transmission characteristics between one rotating part and another rotating part can be divided into multiple stages, and the operation of various mechanical devices can be carried out smoothly, for example, the steering wheel (refer to Figure 1 ) has a good operational feel.

[0163] In the torque transmission joint 1 of this example, when the first elastomer 5 is assembled to the other axial side portion of the coupling 4, that is, when the annular first supported portion 36 of the first elastomer 5 is externally embedded in the first supporting portion 19 of the coupling 4, it is necessary to elastically expand the gap between the first outer snap-fit piece 39 and the first inner snap-fit piece 40 constituting the first supported portion 36 so that the first claw portion 26 present at the end portion on the other axial side of the first supporting portion 19 can pass axially between the first outer snap-fit piece 39 and the first inner snap-fit piece 40.

[0164] In this regard, in this example, the side surfaces on the other axial side of the first claw portion 26 (the first outer claw portion 27 and the first inner claw portion 28) are formed by inclined guide surfaces 32 and 33. These inclined guide surfaces 32 and 33 are inclined in a direction in which the axial width of the first claw portion 26 decreases as it moves radially toward the distal end. Therefore, when the first supported portion 36 is pressed into the periphery of the first supporting portion 19 from the other axial side, the first outer engaging piece 39 and the first inner engaging piece 40 constituting the first supported portion 36 elastically deform along the inclined guide surfaces 32 and 33 of the first claw portion 26, increasing the distance therebetween. Furthermore, the first claw portion 26 passes axially between the first outer engaging piece 39 and the first inner engaging piece 40.

[0165] After passing through, the gap between the first outer engaging piece 39 and the first inner engaging piece 40 elastically returns to its original position, and the first supported portion 36 is fitted externally to the first supporting portion 19. Thus, in this example, the inclined guide surfaces 32 and 33 of the first claw portion 26 facilitate the process of fitting the first supported portion 36 externally to the first supporting portion 19, that is, the process of assembling the first elastic body 5 to the axially opposite side portion of the coupling 4. However, when implementing the structure of the present invention, the axially opposite side side of the first claw portion can also be formed by a flat surface perpendicular to the axial direction of the coupling.

[0166] Furthermore, in this example, the axially facing side surfaces of the second claw portion 29 (the second outer claw portion 30 and the second inner claw portion 31) of the coupling 4 are formed by inclined guide surfaces 34 and 35, which are inclined in a direction in which the axial width of the second claw portion 29 decreases as it moves radially toward the distal end. Therefore, for the same reason, the inclined guide surfaces 34 and 35 of the second claw portion 29 facilitate the process of fitting the second supported portion 43 onto the second supporting portion 20, that is, the process of assembling the second elastic body 6 onto the axially facing portion of the coupling 4. However, when implementing the structure of the present invention, the axially facing side surfaces of the second claw portion can also be formed by flat surfaces perpendicular to the axial direction of the coupling.

[0167] Furthermore, when implementing the structure of the present invention, the coupling may also be configured such that at least one of the circumferentially opposite ends of the first support portion on the other axial side has a first circumferential claw portion protruding in the circumferential direction, and at least one of the circumferentially opposite ends of the second support portion on the one axial side has a second circumferential claw portion protruding in the circumferential direction. Furthermore, the first circumferential claw portion engages with the first elastic body, thereby preventing the first elastic body from axially falling off the first support portion, and the second circumferential claw portion engages with the second elastic body, thereby preventing the second elastic body from axially falling off the second support portion.

[0168] (2) Assembly method of torque transmission joint

[0169] The assembly method of the torque transmission joint 1 of this example includes: a process of assembling the first elastic body 5 to the other axial side portion of the coupling 4 in a state where the second flat surfaces 24 of the multiple second support parts 20 constituting the coupling 4 are in contact with the upper surface of the support platform; and a process of assembling the second elastic body 6 to the one axial side portion of the coupling 4 in a state where the first flat surfaces 22 of the multiple first support parts 19 constituting the coupling 4 are in contact with the upper surface of the support platform.

[0170] Specifically, in this example, first, Figure 16 As shown in (A), the second flat surfaces 24 of the plurality of second support portions 20 constituting the coupling 4 are brought into contact with the upper surface 51 of the support platform 50 constituted by the horizontal surface. Figure 16 (A) to Figure 16 As shown in the procedure of (B), the first elastic body 5 is assembled to the other axial side portion of the coupling 4. That is, the first supported portions 36 of the first elastic body 5 are fitted around the first supporting portions 19 of the coupling 4 in a manner of being press-fitted from above toward below.

[0171] As described above, this external fitting operation can be easily performed using the inclined guide surfaces 32 and 33 of the first claw portion 26. Furthermore, in this example, the external fitting operation can be performed while the second flat surfaces 24 of the plurality of second support portions 20 constituting the coupling 4 are in contact with the upper surface 51 of the support base 50, that is, while the posture of the coupling 4 is stabilized. Therefore, this aspect also facilitates the external fitting operation.

[0172] In this example, then, Figure 16 (B) to Figure 16 As shown in the sequence of (C), the combined coupling 4 and the first elastic body 5 are reversed up and down, so that the first flat surface 22 of the plurality of first support portions 19 constituting the coupling 4 abuts against the upper surface 51 of the support platform 50. Then, in this state, as shown in Figure 16 (C) to Figure 16 As shown in the procedure of (C), the second elastic body 6 is assembled to the axial side portion of the coupling 4. That is, the second supported portions 43 of the second elastic body 6 are fitted around the second supporting portions 20 of the coupling 4 in a manner of being pressed from above toward below.

[0173] As described above, this external fitting operation can be easily performed using the inclined guide surfaces 34 and 35 of the second claw portion 29. Furthermore, in this example, the external fitting operation can be performed while the first flat surfaces 22 of each of the plurality of first support portions 19 constituting the coupling 4 are in contact with the upper surface 51 of the support base 50, that is, while the posture of the coupling 4 is stabilized. Therefore, this aspect also facilitates the external fitting operation.

[0174] Furthermore, the order of the step of assembling the first elastic body 5 to the other axial side portion of the coupling 4 and the step of assembling the second elastic body 6 to the one axial side portion of the coupling 4 may be reversed from that in this example.

[0175] In this example, thereafter, a step is performed of inserting the first protrusion 7 of the first rotating member 2 into the portion between the pair of first elastic pieces 38 circumferentially connected by the first connecting portion 37 in the first elastic body 5 and the first recess 14 of the coupling 4, and a step of inserting the second protrusion 10 of the second rotating member 3 into the portion between the pair of second elastic pieces 45 circumferentially connected by the second connecting portion 44 in the second elastic body 6 and the second recess 15 of the coupling 4. The order of these steps can be determined as appropriate.

[0176] (3) Electric power steering

[0177] like Figure 1As shown, the electric power steering device 52 of this example includes a steering wheel 53, a steering shaft 54, a steering column 55, a pair of universal joints 56a, 56b, an intermediate shaft 57, a steering gear unit 58, and an electric motor 59 with a worm reducer to which the torque transmission joint 1 of this example is applied.

[0178] The steering wheel 53 is supported and fixed to the rear end of a steering shaft 54. The steering shaft 54 is rotatably supported inside a steering column 55 supported by the vehicle body. The front end of the steering shaft 54 is connected to a pinion shaft 60 of a steering gear unit 58 via a rear universal joint 56a, an intermediate shaft 57, and a front universal joint 56b.

[0179] Therefore, when the driver rotates the steering wheel 53, the rotation of the steering wheel 53 is transmitted to the pinion shaft 60 via the steering shaft 54, the pair of universal joints 56a and 56b, and the intermediate shaft 57. The rotation of the pinion shaft 60 is converted into linear motion of the rack shaft (not shown) of the steering gear unit 58, which meshes with the pinion shaft 60. As a result, the pair of tie rods 61 push and pull, thereby imparting a steering angle corresponding to the amount of rotation of the steering wheel 53 to the left and right steering wheels.

[0180] The electric power steering system 52 of this example is configured to reduce the force required for the driver to operate the steering wheel 53 by applying power from an electric motor 59 with a worm gear reducer to the steering shaft 54 .

[0181] (4) Electric motor with worm reducer

[0182] The electric motor with a worm reducer 59 includes an electric motor 62 , a worm reducer 63 , and a torque transmission joint 1 .

[0183] The electric motor 62 has an output shaft 64. The electric motor 62 drives the output shaft 64 to rotate in two directions when energized.

[0184] The worm speed reducer 63 includes a housing 65 , a worm wheel 66 , and a worm 67 .

[0185] The housing 65 includes a worm wheel accommodating portion 68 and a worm accommodating portion 69 having a center axis twisted relative to the center axis of the worm wheel accommodating portion 68 and an axially intermediate portion thereof opening toward the worm wheel accommodating portion 68 .

[0186] The worm wheel housing portion 68 is supported and fixed to the front end portion of the steering column 55 so that its central axis is coaxial with the central axis of the steering column 55 .

[0187] The worm housing portion 69 is formed in a cylindrical shape and has openings at both ends in the axial direction. Figure 2The opening of the worm housing portion 69 is blocked by the cover 70. The other axial side of the worm housing portion 69 ( Figure 2 The opening on the right side of the housing 65 is blocked by the electric motor 62 fixed to the housing 65.

[0188] In addition, regarding the worm housing portion 69 and the components housed in the worm housing portion 69, one side in the axial direction is Figure 2 The left side of the axis is Figure 2 on the right side of the .

[0189] The worm housing portion 69 has a cylindrical surface portion 71 on the inner peripheral surface of the other axial side portion, and a step portion 72 facing the other axial side at the end portion of one axial side of the cylindrical surface portion 71 .

[0190] The worm wheel 66 has gear teeth 73 on its outer circumference and is rotatably supported inside a worm wheel housing 68. In this example, the worm wheel 66 is supported and fixed around the front end of the steering shaft 54 so as to rotate integrally with the steering shaft 54, which is rotatably supported inside the worm wheel housing 68. Furthermore, the worm wheel 66 of this example has a synthetic resin gear portion 75 having gear teeth 73 on its outer circumference, fixedly coupled around a metal, annular plate-shaped core portion 74.

[0191] The worm 67 has threaded worm teeth 76 on the outer peripheral surface of the axially intermediate portion that mesh with the gear teeth 73 of the worm wheel 66 , and is rotatably supported inside the worm accommodating portion 69 .

[0192] Specifically, the worm 67 includes a fitting cylindrical portion 77 on the axially opposite side of the worm teeth 76. This fitting cylindrical portion 77 is rotatably supported by a ball bearing 78 relative to the cylindrical surface portion 71 of the worm housing 69. The outer ring 79 of the ball bearing 78 is press-fitted into the cylindrical surface portion 71, with its axially opposite side surface abutting the step 72. The inner ring 80 of the ball bearing 78 is fitted externally into the fitting cylindrical portion 77 with a clearance fit. Furthermore, the inner ring 80 is axially sandwiched between a flange 81 provided on the worm 67 adjacent to the axially opposite side of the worm teeth 76 and the first rotating member 2 of the torque transmission joint 1, which is externally fitted and fixed to the axially opposite end of the worm 67, via a pair of worm dampers 82.

[0193] As a result, the fitting cylindrical portion 77 of the worm 67 is supported so as to be rotatable and swingable relative to the cylindrical surface portion 71 of the worm accommodating portion 69 .

[0194] The structure for supporting the portion of the worm 67 located on the other axial side of the worm teeth 76 so as to be rotatable and swingable relative to the worm accommodating portion 69 is not limited to that of this example, and various structures may be employed.

[0195] The axial end of the worm 67 is supported by a ball bearing 83 for free rotation relative to the inner circumference of the worm housing 69. An urging mechanism 84, comprised of an elastic member such as a coil spring or leaf spring, is assembled between the outer circumference of the ball bearing 83 and the inner circumference of the worm housing 69. This urging mechanism 84 elastically urges the worm teeth 76 of the worm 67 toward the gear teeth 73 of the worm wheel 66. This structure reduces backlash between the worm teeth 76 and the gear teeth 73, thereby suppressing any rattling noise.

[0196] The mechanism for elastically urging the end portion on one axial side of the worm 67 toward the worm wheel 66 is not limited to the configuration of this example, and various configurations can be employed.

[0197] The torque transmission joint 1 connects one axial end of the output shaft 64 of the electric motor 62 to the other axial end of the worm gear 67 to enable torque transmission. Therefore, the first rotating member 2 of the torque transmission joint 1 is externally fixed to the one axial end of the output shaft 64 of the electric motor 62, and the second rotating member 3 of the torque transmission joint 1 is externally fixed to the other axial end of the worm gear 67.

[0198] Therefore, in the electric motor 59 with a worm reducer in this example, even if the worm 67 swings or is eccentric relative to the output shaft 64 of the electric motor 62 during operation, in the torque transmission joint 1, the coupling 4 elastically deforms the first elastic body 5 and / or the second elastic body 6 and tilts relative to the center axis of the output shaft 64 of the electric motor 62 and / or the center axis of the worm 67, thereby enabling smooth torque transmission between the output shaft 64 of the electric motor 62 and the worm 67.

[0199] The electric motor 59 with a worm reducer in this example is arranged to apply power to the steering shaft 54. However, the structure of the present invention can also be applied to an electric motor with a worm reducer arranged to apply power to the pinion shaft or rack shaft of the steering gear unit.

[0200] [Second example]

[0201] use Figures 17 to 21 A second example of the embodiment of the present invention will be described.

[0202] In the torque transmission joint constituting the worm reducer of this example, Figures 17 to 19 As shown, the first elastic body 5a is formed on the side surface of the first elastic piece 38a on the other side of the axial direction and on the first rotating member 2a (see Figure 20 (A) and Figure 20The connection portion of the circumferential side surface of the first protrusion 7a (B)) opposite the circumferential outer surface has a first chamfered portion 91. In this example, the first chamfered portion 91 is formed by a C-chamfered portion. However, when implementing the present invention, the first chamfered portion can also be formed by an R-chamfered portion.

[0203] In this example, the first elastic body 5a has a first connecting chamfered portion 93 at the connection portion between the side surface on the other axial side of the first connecting portion 37a and the radially inner side surface. The ends on both axial sides of the first connecting chamfered portion 93 are connected to the radially outer ends of a pair of first chamfered portions 91 adjacent to each other in the circumferential direction across the first connecting chamfered portion 93. In this example, the first connecting chamfered portion 93 is composed of a C chamfered portion. However, in the case of implementing the present invention, the first connecting chamfered portion may also be composed of an R chamfered portion. In addition, in the case of implementing the present invention, the first connecting chamfered portion may be omitted when the first connecting portion is provided.

[0204] In this example, when the first protrusion 7a of the first rotating component 2a is inserted into the portion between a pair of first elastic pieces 38a connected in the circumferential direction by the first connecting portion 37a in the first elastic body 5a in order to assemble the torque transmission joint, the first chamfered portion 91 and the first connecting chamfered portion 93 are used as guide surfaces to facilitate the insertion operation.

[0205] In this example, if Figures 17 to 19 As shown, the second elastic body 6a is formed on the side surface of the second elastic piece 45a on the axial side and the second elastic piece 45a in the second rotating member 3a (see Figure 21 (A) and Figure 21 The connecting portion of the circumferential side surface of the second protrusion 10a (B)) facing the circumferential outer surface has a second chamfered portion 92. In this example, the second chamfered portion 92 is formed by a C-chamfered portion. However, when implementing the present invention, the second chamfered portion can also be formed by an R-chamfered portion.

[0206] In this example, the second elastic body 6a has a second connecting chamfered portion 94 at the connection portion between the side surface on one axial side of the second connecting portion 44a and the radially inner side surface. The ends on both axial sides of the second connecting chamfered portion 94 are connected to the radially outer ends of a pair of second chamfered portions 92 adjacent to each other in the circumferential direction across the second connecting chamfered portion 94. In this example, the second connecting chamfered portion 94 is composed of a C chamfered portion. However, in the case of implementing the present invention, the second connecting chamfered portion may also be composed of an R chamfered portion. In addition, in the case of implementing the present invention, the second connecting chamfered portion may also be omitted when the second connecting portion is provided.

[0207] In this example, when the second protrusion 10a of the second rotating component 3a is inserted into the portion between a pair of second elastic pieces 45a connected in the circumferential direction by the second connecting portion 44a in the second elastic body 6a in order to assemble the torque transmission joint, the second chamfered portion 92 and the second connecting chamfered portion 94 are used as guide surfaces to facilitate the insertion operation.

[0208] In this example, if Figure 20 (A) and Figure 20 As shown in FIG. 2 (B), the first rotating member 2a includes first corner portions 95 at the connection between the circumferentially opposite side surfaces of the first protrusion 7a and the axially opposite side surface of the first base portion 8a. These first corner portions 95 are inclined circumferentially away from the center portion of the first protrusion 7a as they approach the other axial side. This reduces stress concentration at the connection between the circumferentially opposite side surfaces of the first protrusion 7a and the axially opposite side surface of the first base portion 8a when torque is transmitted through the torque transmission joint.

[0209] In this example, the first corner 95 is formed by a plane linearly inclined relative to the axial direction. However, when implementing the present invention, the first corner may be formed by a concave surface curved relative to the axial direction, that is, a rounded corner.

[0210] In this example, the first elastic body 5a has a first chamfered portion 91 at the connection between the side surface on the other axial side of the first elastic piece 38a and the circumferential side surface of the first elastic piece 38a that faces the circumferential outer side of the first protrusion 7a of the first rotating member 2a. Therefore, when the electric motor with a worm reducer is assembled, when the side surface on one axial side of the first base portion 8a of the first rotating member 2a abuts the side surface on the other axial side of the first elastic body 5a, the connection portion (first chamfered portion 91) of the first elastic piece 38a can be suppressed or prevented from being elastically crushed by the first corner 95.

[0211] This improves the smoothness of the relative tilting occurring between the first rotating member 2a and the coupling 4, and thus makes it possible to improve the ability of the torque transmission joint to absorb misalignment between the output shaft of the electric motor and the worm.

[0212] In this example, the axial width Wa1 of the first chamfered portion 91 of the first elastic body 5a is set to be greater than or equal to the axial width Wb1 of the first corner portion 95 of the first rotating member 2a (Wa1 ≥ Wb1), and the circumferential width Wa2 of the first chamfered portion 91 is set to be greater than or equal to the circumferential width Wb2 of the first corner portion 95 (Wa2 ≥ Wb2). Therefore, when the axial side surface of the first base portion 8a of the first rotating member 2a contacts the axial side surface of the first elastic body 5a, the connection portion (first chamfered portion 91) can be more effectively suppressed or prevented from being elastically crushed by the first corner portion 95.

[0213] In this example, if Figure 21 (A) and Figure 21 As shown in FIG. 1B , the second rotating member 3a includes second corners 96 at the connection between the circumferentially opposite side surfaces of the second protrusion 10a and the axially opposite side surface of the second base portion 12a. These second corners 96 are inclined circumferentially away from the center of the second protrusion 10a as they move toward the axial side. This reduces stress concentration at the connection between the circumferentially opposite side surfaces of the second protrusion 10a and the axially opposite side surface of the second base portion 12a when torque is transmitted through the torque transmission joint.

[0214] In this example, the second corner portion 96 is formed by a plane inclined linearly with respect to the axial direction. However, when implementing the present invention, the second corner portion may be formed by a concave surface inclined curvedly with respect to the axial direction, that is, a rounded corner portion.

[0215] In this example, the second elastic body 6a has a second chamfered portion 92 at the connection between the axially one side surface of the second elastic piece 45a and the circumferential side surface of the second elastic piece 45a that faces the circumferentially outer surface of the second protrusion 10a of the second rotational member 3a. Therefore, when the worm reducer including the torque transmission joint is assembled, when the axially other side surface of the second base portion 12a of the second rotational member 3a contacts the axially one side surface of the second elastic body 6a, the connection portion (second chamfered portion 92) of the second elastic piece 45a can be prevented or suppressed from being elastically crushed by the second corner 96.

[0216] This improves the smoothness of the relative tilting occurring between the second rotating member 3 a and the coupling 4 , thereby improving the ability of the torque transmission joint to absorb misalignment between the output shaft of the electric motor and the worm.

[0217] In this example, the axial width dimension Wc1 of the second chamfered portion 92 of the second elastic body 6a is set to be greater than or equal to the axial width dimension Wd1 of the second corner portion 96 of the second rotational member 3a (Wc1 ≥ Wd1), and the circumferential width dimension Wc2 of the second chamfered portion 92 is set to be greater than or equal to the circumferential width dimension Wd2 of the second corner portion 96 (Wc2 ≥ Wd2). Therefore, when the axially opposite side surface of the second base portion 12a of the second rotational member 3a contacts the axially opposite side surface of the second elastic body 6a, the connection portion (second chamfered portion 92) of the second elastic piece 45a can be more effectively suppressed or prevented from being elastically crushed by the second corner portion 96.

[0218] The other structures and effects of the second example are the same as those of the first example.

[0219] When implementing the electric motor with a worm reducer of the present invention, the first rotating member of the torque transmission joint can be integrally formed with one rotating member such as the output shaft of the electric motor, or the second rotating member of the torque transmission joint can be integrally formed with another rotating member such as the worm.

[0220] The electric motor with a worm speed reducer of the present invention is not limited to an electric power steering device, but can be incorporated into various mechanical devices.

[0221] Description of Reference Numerals

[0222] 1Torque transmission joint

[0223] 2.2a First rotating component

[0224] 3.3a Second rotating component

[0225] 4 couplings

[0226] 5.5a First elastic body

[0227] 6.6a Second elastic body

[0228] 7. The first convex part of 7a

[0229] 8, 8a first base

[0230] 9 protrusions

[0231] 10, 10a second convex part

[0232] 11 protuberance

[0233] 12, 12a second base

[0234] 13 protuberance

[0235] 14 first recess

[0236] 15 Second recess

[0237] 16 Arm

[0238] 17 First side panel

[0239] 18 Second side panel

[0240] 19 First support

[0241] 20 Second supporting portion

[0242] 21 Boss

[0243] 22 First flat surface

[0244] 23 First inclined surface

[0245] 24 Second flat surface

[0246] 25 Second inclined surface

[0247] 26 First Claw

[0248] 27 First outer claw

[0249] 28 First inner claw

[0250] 29 Second claw

[0251] 30 Second outer claw

[0252] 31 Second inner claw

[0253] 32 first outer inclined guide surface

[0254] 33 First inner inclined guide surface

[0255] 34 Second outer inclined guide surface

[0256] 35 Second inner inclined guide surface

[0257] 36 first supported portion

[0258] 37, 37a first connecting portion

[0259] 38, 38a first elastic piece

[0260] 39 First outer engaging piece

[0261] 40 First inner engaging piece

[0262] 41 incision

[0263] 42 first elastic protrusion

[0264] 43 Second supported portion

[0265] 44, 44a second connecting portion

[0266] 45, 45a second elastic piece

[0267] 46 Second outer snap-fit piece

[0268] 47 Second inner snap-fit piece

[0269] 48 incision

[0270] 49 second elastic protrusion

[0271] 50 support platform

[0272] 51 upper surface

[0273] 52 Electric power steering

[0274] 53 Steering Wheel

[0275] 54 steering shaft

[0276] 55 Steering column

[0277] 56a, 56b universal joints

[0278] 57 intermediate shaft

[0279] 58 Steering gear unit

[0280] 59 Electric motor with worm reducer

[0281] 60 pinion shaft

[0282] 61 tie rod

[0283] 62 Electric Motor

[0284] 63 Worm reducer

[0285] 64 output shaft

[0286] 65 housing

[0287] 66 worm gear

[0288] 67 Worm

[0289] 68 Worm gear housing

[0290] 69 Worm housing

[0291] 70 cover

[0292] 71 Cylindrical face

[0293] 72 Steps

[0294] 73 gear teeth

[0295] 74 core

[0296] 75 Gear Department

[0297] 76 worm teeth

[0298] 77 fitting cylinder

[0299] 78 ball bearings

[0300] 79 outer ring

[0301] 80 inner circle

[0302] 81 flange

[0303] 82 worm gear damper

[0304] 83 ball bearings

[0305] 84 force-applying mechanism

[0306] 85 through hole

[0307] 86 through hole

[0308] 87 First elastic flat surface

[0309] 88 first elastic inclined surface

[0310] 89 Second elastic flat surface

[0311] 90 Second elastic inclined surface

[0312] 91 First chamfer

[0313] 92 Second chamfer

[0314] 93 First connection chamfer

[0315] 94 Second connection chamfer

[0316] 95 First Corner

[0317] 96 Second corner

Claims

1. A torque transmission joint, characterized in that: have: a first rotating member having first protrusions protruding toward one side in the axial direction at a plurality of locations in the circumferential direction of a side surface of one side in the axial direction; a second rotating member having second protrusions protruding toward the other axial side at a plurality of locations in the circumferential direction of a side surface of the second rotating member on the other axial side; The coupling comprises: a first recess, which is arranged at multiple locations in the circumferential direction, has a circumferential width greater than the circumferential width of the first convex portion, and is open to the other axial side for the first convex portion to be inserted through the opening; a second recess, which is arranged at multiple locations in the circumferential direction, has a circumferential width greater than the circumferential width of the second convex portion, and is open to one axial side for the second convex portion to be inserted through the opening; a first support portion, which protrudes from multiple locations in the circumferential direction of an end portion on the other axial side toward the other axial side and is respectively arranged between a pair of circumferentially adjacent first convex portions of the first convex portion; and a second support portion, which protrudes from multiple locations in the circumferential direction of an end portion on one axial side toward the one axial side and is respectively arranged between a pair of circumferentially adjacent second convex portions of the second convex portion; a first elastic body having: an annular first supported portion, the first supported portion being arranged at a plurality of locations in the circumferential direction and being fitted onto the first protrusion; and a plurality of first connecting portions, each of the plurality of first connecting portions circumferentially connecting radially outer end portions or radially inner end portions of a pair of circumferentially adjacent first supported portions of the first supported portion, wherein a portion of the first supported portion located between the circumferentially adjacent first protrusion and the first supporting portion, i.e., a first elastic piece, is circumferentially held between the first protrusion and the first supporting portion; as well as a second elastic body having an annular second supported portion, the second supported portion being arranged at a plurality of locations in the circumferential direction and being fitted onto the second protrusion; and a plurality of second connecting portions, wherein the plurality of second connecting portions respectively connect radially outer end portions or radially inner end portions of a pair of circumferentially adjacent second supported portions in the second supported portion in the circumferential direction, and a portion of the second supported portion located between the circumferentially adjacent second protrusions and the second supporting portion, i.e., the second elastic piece, is clamped between the second protrusions and the second supporting portion in the circumferential direction. The coupling comprises: a first claw portion, the first claw portion radially protruding from at least one of a radially outer side and a radially inner side of an end portion on the other axial side of the first support portion; and a second claw portion radially protruding from at least one of a radially outer side and a radially inner side of an end portion on one axial side of the second support portion. The first claw portion engages with the first supported portion from the other axial side. The second claw portion engages with the second supported portion from one axial side.

2. The torque transmission joint according to claim 1, characterized in that In the coupling, the second recesses are respectively arranged at a plurality of locations in the circumferential direction between a pair of first recesses adjacent to each other in the circumferential direction in the first recesses. The coupling comprises: a plurality of arm portions, each of the plurality of arm portions separating the first recess and the second recess adjacent to each other in the circumferential direction; a plurality of first side plates, each of the plurality of first side plates connecting ends on one axial side of a pair of arm portions existing on both sides of the circumferential direction of the first recess among the plurality of arm portions in the circumferential direction; and a plurality of second side plates, each of the plurality of second side plates connecting ends on the other axial side of a pair of arm portions existing on both sides of the circumferential direction of the second recess among the plurality of arm portions in the circumferential direction. The first support portion protrudes from the side surface of the second side plate portions on the other axial side toward the other axial side, and the second support portion protrudes from the side surface of the first side plate portions on one axial side toward the one axial side.

3. The torque transmission joint according to claim 1, characterized in that The side surface on the other axial side of the first claw portion and the side surface on one axial side of the second claw portion are formed by inclined guide surfaces inclined in a direction in which the axial width decreases as the axial width increases toward the distal end in the radial direction.

4. The torque transmission joint according to claim 1, wherein: The first claw portion is provided on both the radially outer side and the radially inner side of the end portion on the other axial side of the first support portion. The second claw portion is provided on both the radially outer side and the radially inner side of the end portion on one axial side of the second support portion. The plurality of first connecting portions respectively connect the radially outer end portions of a pair of the first supported portions in the circumferential direction, and the circumferential length of the radially outer first claw portion is greater than the circumferential length of the radially inner first claw portion. The plurality of second connection portions respectively connect radially outer end portions of a pair of second supported portions in the circumferential direction, and the circumferential length of the radially outer second claw portion is greater than the circumferential length of the radially inner second claw portion.

5. The torque transmission joint according to claim 1, wherein: The first elastic piece has a first elastic protrusion on a radial portion of a circumferential side surface facing the circumferential outer side surface of the first convex portion, the first elastic protrusion protruding in the circumferential direction and abutting against the circumferential outer side surface of the first convex portion with an interference fit. The second elastic piece has a second elastic protrusion on a radial portion of a circumferential side surface facing the circumferential outer surface of the second convex portion. The second elastic protrusion protrudes circumferentially and abuts against the circumferential outer surface of the second convex portion with an interference fit.

6. The torque transmission joint according to claim 1, wherein: The first elastic body has a first chamfered portion at a connection portion between a side surface on the other axial side of the first elastic piece and a circumferential side surface of the first elastic piece that faces the circumferential outer side of the first protrusion. The second elastic body has a second chamfered portion at a connection portion between a side surface on one axial side of the second elastic piece and a circumferential side surface of the second elastic piece facing a circumferential outer surface of the second protrusion.

7. The torque transmission joint according to claim 6, characterized in that The first rotating member includes a first base, the first protrusions protruding toward one side in the axial direction from a plurality of locations in the circumferential direction of a side surface of one axial side of the first base, and the first rotating member includes first corners at connection portions between the side surfaces in the circumferential direction of both sides of the first protrusion and the side surface in the axial direction of the first base, the first corners being inclined in a direction away from a central portion of the first protrusion in the circumferential direction as they go toward the other axial side. The second rotating component has a second base, the second convex portion protrudes toward the other axial side from multiple circumferential positions of the side surface of the second base on the other axial side, and the second rotating component has second corner portions at the connection portions between the side surfaces on both sides of the circumferential direction of the second convex portion and the side surface of the second base on the other axial side, and the second corner portions are inclined in a direction toward a side away from the central portion of the second convex portion in the circumferential direction as they go toward the one axial side.

8. The torque transmission joint according to claim 7, characterized in that The axial width of the first chamfered portion is greater than the axial width of the first corner portion, and the circumferential width of the first chamfered portion is greater than the circumferential width of the first corner portion. The axial width of the second chamfered portion is greater than or equal to the axial width of the second corner portion, and the circumferential width of the second chamfered portion is greater than or equal to the circumferential width of the second corner portion.

9. The torque transmitting joint according to claim 1, wherein: The radially inner portion of the side surface on the other axial side of the first support portion is composed of a first flat surface orthogonal to the axial direction of the coupling, and the radially outer portion of the side surface on the other axial side of the first support portion is composed of a first inclined surface that is inclined in a direction toward the axial side as it moves radially outward. The radially inner portion of the side surface on one axial side of the second support portion is composed of a second flat surface orthogonal to the axial direction of the coupling, and the radially outer portion of the side surface on the other axial side of the second support portion is composed of a second inclined surface that is inclined in a direction toward the other axial side as it moves radially outward.

10. A method for assembling a torque transmission joint, characterized in that: The method for assembling the torque transmission joint according to claim 9 comprises: a step of assembling the first elastic body to the other axial side portion of the coupling in a state where the second flat surface of the second support portion of the coupling is in contact with the upper surface of the support base; and A step of assembling the second elastic body to one axial side portion of the shaft coupling in a state in which the first flat surface constituting the first support portion of the shaft coupling is in contact with an upper surface of a support base.

11. An electric motor with a worm reducer, characterized in that: have: an electric motor having an output shaft; A worm reducer comprising: a worm wheel having gear teeth on an outer peripheral surface; and a worm having worm teeth on an outer peripheral surface meshing with the gear teeth; and a torque transmission joint connecting the output shaft and the worm in a torque-transmittable manner; The torque transmission joint is constituted by the torque transmission joint according to any one of claims 1 to 9, The first rotating member is fixed to the output shaft or is integrally formed with the output shaft. The second rotating member is fixed to the worm or is integrally formed with the worm.

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