Power transmission device

Abstract

Provided is a power transmission device capable of prolonging the life of a biasing member. The first plate is disposed on a first side in the axial direction with respect to the flange plate. The second plate is disposed on a second side in the axial direction with respect to the flange plate. The elastic member elastically connects the input rotating body and the output rotating body. The first shaft is mounted to the hub. The first helical gear is fixed to the first shaft. The first helical gear is configured so as to act a thrust force toward a first side in the axial direction when rotating in the rotational direction. The second shaft extends along the first shaft. The second helical gear is mounted to the second shaft. The second bevel gear is meshed with the first bevel gear. The biasing member is disposed between the flange plate and the second plate.

Description

Technical Field

[0001] The present invention relates to a power transmission device. Background Art

[0002] The power transmission device is configured to absorb and attenuate torque fluctuations from an internal combustion engine. The power transmission device includes first and second plates, an output rotor, and a plurality of elastic members (see, for example, Patent Document 1). Each elastic member elastically connects the first and second plates to the output rotor.

[0003] Furthermore, to suppress resonance, the power transmission device includes a friction member and a biasing member. The friction member and biasing member are disposed between the first plate and the flange plate of the output member. The biasing member biases the friction member toward the flange plate. The friction member and the flange plate are frictionally engaged, thereby suppressing resonance.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-227222 Summary of the Invention

[0005] It is desired to extend the service life of a biasing member used in a power transmission device. Therefore, a technical problem of the present invention is to provide a power transmission device capable of extending the service life of a biasing member.

[0006] The power transmission device involved in the first embodiment includes an output rotating body, an input rotating body, an elastic member, a first shaft, a first helical gear, a second shaft, a second helical gear, and a force application member. The output rotating body has a hub and a flange plate. The input rotating body has a first plate and a second plate. The first plate is arranged on a first axial side relative to the flange plate. The second plate is arranged on a second axial side relative to the flange plate. The elastic member elastically connects the input rotating body and the output rotating body. The first shaft is mounted on the hub. The first helical gear is fixed to the first shaft. The first helical gear is configured to apply a thrust toward the first axial side when rotating in the rotational direction. The second shaft extends along the first shaft. The second helical gear is mounted on the second shaft. The second helical gear meshes with the first helical gear. The force application member is arranged between the flange plate and the second plate.

[0007] With this structure, when the power transmission device rotates due to torque from a prime mover such as an internal combustion engine, the first helical gear rotates in the rotational direction, exerting a thrust in the first axial direction on the first helical gear. Consequently, a load in the first axial direction is applied to the flange plate. Because the coil spring is positioned between the flange plate and the second plate, it is not subjected to an axial load caused by the thrust acting on the first helical gear. As a result, wear of the coil spring can be suppressed, extending its lifespan.

[0008] A power transmission device according to a second aspect is the power transmission device according to the first aspect, and further includes an electric motor attached to the second shaft.

[0009] In addition to the power transmission device according to the first or second embodiment, a power transmission device according to the third embodiment is configured as follows: A first shaft extends from the hub to a first side in the axial direction. The first helical gear is configured so that, when rotating in the rotational direction, a thrust force acts in the direction in which the first shaft extends.

[0010] A power transmission device according to a fourth aspect is configured as follows in addition to the power transmission device according to any one of the first to third aspects: The torsion direction and the rotation direction of the first helical gear are the same.

[0011] A fifth aspect of the power transmission device according to any one of the first to fourth aspects is configured as follows: The first helical gear has a larger outer diameter than the second helical gear.

[0012] A sixth aspect of the power transmission device according to any one of the first to fifth aspects further includes a friction member disposed between the biasing member and the flange plate and biasing the friction member toward the flange plate.

[0013] According to the present invention, the service life of the urging member can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view of the power transmission device.

[0015] Figure 2 It is an enlarged cross-sectional view of the power transmission device.

[0016] Figure 3 It is a cross-sectional view of a power transmission device according to a modified example.

[0017] Description of Reference Numerals

[0018] 2…output rotating body; 21…flange plate; 22…hub; 3…input rotating body; 31…first plate; 32…second plate; 4…elastic member; 6…second friction member; 7…first coil spring; 13…first shaft; 14…gear; 15…second shaft; 16…gear; 17…electric motor; 100…power transmission device. DETAILED DESCRIPTION

[0019] Hereinafter, the power transmission device 100 according to the present embodiment will be described with reference to the accompanying drawings. In the following description, the axial direction refers to the direction in which the rotation axis O of the power transmission device 100 extends. Furthermore, the circumferential direction refers to the circumferential direction of a circle centered on the rotation axis O, and the radial direction refers to the radial direction of a circle centered on the rotation axis O. Furthermore, the first side in the axial direction refers to the direction of the thrust acting on the first helical gear 14 when the first helical gear 14 described later rotates in the rotation direction. In this embodiment, the first side in the axial direction refers to the direction in which the thrust acting on the first helical gear 14 is rotated in the rotation direction. Figure 1 In addition, the second side in the axial direction refers to the side opposite to the first side in the axial direction.

[0020] Figure 1 is a cross-sectional view of the power transmission device. Figure 1 As shown, the power transmission device 100 includes a vibration damping unit 11 and a torque limiting unit 12 , a first shaft 13 , a first helical gear 14 , a second shaft 15 , a second helical gear 16 , and an electric motor 17 .

[0021] The vibration damping unit 11 and the torque limiting unit 12 rotate substantially integrally with each other. The power transmission device 100 is provided between an internal combustion engine (not shown) and an output-side member (not shown). The output-side member is, for example, a transmission. The power transmission device 100 is attached to a flywheel 101. Figure 1 In FIG, the internal combustion engine is arranged on the left side of the power transmission device 100, and the output-side member is arranged on the right side of the power transmission device 100. The power transmission device 100 is configured to limit the torque transmitted between the internal combustion engine and the output-side member and to attenuate torque fluctuations.

[0022] [Vibration damping unit]

[0023] Figure 2 1 is a cross-sectional view of the vibration reduction unit 11 and the torque limiting unit 12. Figure 2 As shown, the vibration damping unit 11 is attached to the torque limiting unit 12. The vibration damping unit 11 is configured to dampen rotational fluctuations. The vibration damping unit 11 includes an output rotor 2, an input rotor 3, multiple elastic members 4, a first friction member 5, a second friction member 6 (an example of a friction member), a first coil spring 7 (an example of a biasing member), and a friction disk 8.

[0024] Output Rotating Body

[0025] The output rotor 2 is configured to transmit torque from the input rotor 3 to the output-side member. The output rotor 2 is disposed rotatably around a rotation axis O.

[0026] The output rotor 2 includes a flange plate 21 and a hub 22. The flange plate 21 and the hub 22 are configured to rotate integrally.

[0027] The flange plate 21 has an opening 211 in the center. That is, the flange plate 21 is annular. Furthermore, the flange plate 21 has a plurality of receiving holes 212 . The receiving holes 212 are spaced apart from each other in the circumferential direction. Each receiving hole 212 is configured to receive the elastic member 4 .

[0028] The hub 22 is cylindrical and extends axially. It axially penetrates the openings of the first plate 31 and the second plate 32, described later. The hub 22 has a spline hole 221 extending axially. The first shaft 13 is spline-fitted into the spline hole 221.

[0029] The hub 22 is press-fitted into the opening 211 of the flange plate 21. Therefore, the hub 22 rotates integrally with the flange plate 21. In other words, the hub 22 does not rotate relative to the flange plate 21. Alternatively, the hub 22 may be formed integrally with the flange plate 21 using a single member.

[0030] <Input Rotating Body>

[0031] The input rotor 3 is configured to rotate relative to the output rotor 2. The input rotor 3 includes a first plate 31 and a second plate 32. Both the first plate 31 and the second plate 32 are annular members with an opening at the center. The hub 22 of the output rotor 2 extends through the openings of the first and second plates 31 and 32.

[0032] The first plate 31 and the second plate 32 rotate integrally with each other. In addition, the first plate 31 and the second plate 32 cannot move relative to each other in the axial direction.

[0033] The first plate 31 and the second plate 32 are arranged at a distance from each other in the axial direction. The flange plate 21 is arranged axially between the first plate 31 and the second plate 32. The first plate 31 and the second plate 32 are arranged to be rotatable relative to the flange plate 21.

[0034] The first plate 31 is disposed on a first axial side relative to the flange plate 21. The first plate 31 is spaced apart from the flange plate 21 in the axial direction. Furthermore, the second plate 32 is disposed on a second axial side relative to the flange plate 21. The second plate 32 is spaced apart from the flange plate 21 in the axial direction.

[0035] The first plate 31 and the second plate 32 each have a plurality of windows 311 and 321. The windows 311 and 321 are spaced apart from each other in the circumferential direction. Each window 311 and 321 is configured to accommodate the elastic member 4. When viewed in the axial direction, each window 311 and 321 is arranged at a position that overlaps with each receiving hole 212.

[0036] <Elastic member>

[0037] The elastic member 4 is configured to elastically couple the input rotor 3 and the output rotor 2 in the rotational direction. Specifically, the elastic member 4 elastically couples the flange plate 21 and the first and second plates 31 and 32 in the rotational direction. The elastic member 4 is, for example, a coil spring.

[0038] The elastic member 4 is received in the receiving hole 212 of the flange plate 21 . Furthermore, the elastic member 4 is received in the window portion 311 of the first plate 31 and also in the window portion 321 of the second plate 32 .

[0039] <First Friction Member>

[0040] The first friction member 5 is axially disposed between the flange plate 21 and the first plate 31. The first friction member 5 is annular and extends circumferentially. The first friction member 5 is configured to rotate integrally with the flange plate 21. Alternatively, the first friction member 5 may rotate relative to the flange plate 21 within a predetermined range.

[0041] The first friction member 5 is arranged to be rotatable relative to the first plate 31. The relative rotation of the first friction member 5 relative to the first plate 31 generates frictional force.

[0042] <Second Friction Member>

[0043] The second friction member 6 is axially disposed between the flange plate 21 and the second plate 32. Specifically, the second friction member 6 is disposed between the flange plate 21 and the first coil spring 7. The second friction member 6 is annular and extends circumferentially. The second friction member 6 is configured to rotate integrally with the second plate 32. The second friction member 6 is rotatable relative to the flange plate 21.

[0044] Coil spring

[0045] The first coil spring 7 is positioned between the flange plate 21 and the second plate 32. Specifically, the first coil spring 7 is positioned on the second axial side relative to the flange plate 21. Specifically, the first coil spring 7 is positioned between the second friction member 6 and the second plate 32. The first coil spring 7 axially biases the second friction member 6 toward the flange plate 21. This generates frictional force when the second friction member 6 rotates relative to the flange plate 21.

[0046] Friction disc

[0047] The friction disk 8 is attached to the outer peripheral end of the input rotor 3. Specifically, the friction disk 8 is attached to the first plate 31 via a fastening member 37. Alternatively, the friction disk 8 may be attached to the second plate 32. The friction disk 8 rotates integrally with the input rotor 3. Rivets can be used as examples of the fastening member 37.

[0048] The friction disc 8 is annular and includes a support plate 81, a first friction member 82, and a second friction member 83. The support plate 81, the first friction member 82, and the second friction member 83 rotate integrally with each other.

[0049] The support plate 81 is attached to the first plate 31. For example, the support plate 81 is attached to the first plate 31 by the fastening member 37. In addition, the support plate 81 is a separate member from the first plate 31, but the support plate 81 and the first plate 31 may be integrally formed as a single member.

[0050] The first and second friction members 82 and 83 are annular. The first friction member 82 is attached to one side of the support plate 81, and the second friction member 83 is attached to the other side of the support plate 81. The first and second friction members 82 and 83 rotate integrally with the support plate 81.

[0051] When a torque greater than a predetermined value is input to the power transmission device 100, the friction disc 8 slides relative to the side plate 91 and the pressure plate 93 via the first and second friction members 82 and 83, and rotates relative to the side plate 91 and the pressure plate 93. On the other hand, when a torque less than the predetermined value is input, the friction disc 8 rotates integrally with the side plate 91 and the pressure plate 93.

[0052] [Torque limiter]

[0053] The torque limiting unit 12 is arranged to be rotatable about the rotation axis O. The torque limiting unit 12 is arranged on a first side in the axial direction relative to the flywheel 101. The torque limiting unit 12 is annular and is attached to the flywheel 101.

[0054] The torque limiting unit 12 is configured to limit the torque transmitted between the flywheel 101 and the vibration damping unit 11. Specifically, the torque limiting unit 12 is configured to limit the transmission of torque exceeding a predetermined value in the power transmission device 100. The torque limiting unit 12 is configured to frictionally engage with the friction disk 8. Furthermore, the torque limiting unit 12 sandwiches the friction disk 8 in the axial direction.

[0055] The torque limiting unit 12 includes a side plate 91 , a cover plate 92 , a pressure plate 93 , and a second coil spring 94 .

[0056] The side plate 91 and the cover plate 92 are attached to the flywheel 101. The side plate 91 and the cover plate 92 rotate integrally with the flywheel 101. The side plate 91 and the cover plate 92 are annular. The cover plate 92 is positioned on the second side in the axial direction relative to the side plate 91. The cover plate 92 is thinner than the side plate 91.

[0057] The pressure plate 93 is annular. It is axially positioned between the side plate 91 and the cover plate 92. Specifically, the pressure plate 93 is axially positioned between the second friction member 83 and the second disc spring 94. The pressure plate 93 is configured to rotate integrally with the side plate 91. Furthermore, the pressure plate 93 is axially movable relative to the side plate 91.

[0058] The second coil spring 94 is axially disposed between the cover plate 92 and the pressure plate 93. The second coil spring 94 biases the pressure plate 93 toward the first side in the axial direction. In other words, the second coil spring 94 biases the pressure plate 93 toward the friction disk 8. As a result, the friction disk 8 is sandwiched between the pressure plate 93 and the side plate 91.

[0059] [First axis]

[0060] The first shaft 13 is mounted on the hub 22 of the output rotor 2. Specifically, the first shaft 13 is spline-engaged with the spline hole 221 of the hub 22. The first shaft 13 rotates integrally with the hub 22. The first shaft 13 extends from the hub 22 toward a first axial side. The rotation axis of the first shaft 13 is coaxial with the rotation axis O of the power transmission device 100.

[0061] [First helical gear]

[0062] like Figure 1 As shown, the first helical gear 14 is fixed to the first shaft 13 and rotates integrally with the first shaft 13. In addition, the first helical gear 14 moves integrally with the first shaft 13 in the axial direction.

[0063] The first helical gear 14 meshes with the second helical gear 16. When the first helical gear 14 rotates and transmits torque to the second helical gear 16, thrust acts on the first and second helical gears 14, 16. The direction of the thrust acting on the first helical gear 14 when the first helical gear 14 rotates in the rotational direction due to the torque from the internal combustion engine, i.e., when torque is transmitted from the first helical gear 14 to the second helical gear 16, is referred to as the first axial side. In other words, the first helical gear 14 is configured so that thrust acts on the first axial side when it rotates in the rotational direction due to the torque from the internal combustion engine.

[0064] The rotational direction is the direction in which the first helical gear 14 rotates when the internal combustion engine rotates. Specifically, the rotational direction is the direction in which the first helical gear 14 rotates when torque from the internal combustion engine is transmitted. When the flywheel 101 is viewed along the axial direction from the second axial side, the internal combustion engine rotates clockwise. That is, in this embodiment, the rotational direction is clockwise when viewed along the axial direction from the second axial side.

[0065] The first helical gear 14 is configured so that a thrust acts in the direction in which the first shaft 13 extends. That is, the thrust acting on the first helical gear 14 is in the same direction as the direction in which the first shaft 13 extends from the wheel hub 22. The twisting direction of the first helical gear 14 is in the same direction as the rotational direction. That is, the first helical gear 14 twists in the direction of rotation. Furthermore, in this embodiment, the first helical gear 14 is clockwise twisted. Thus, when torque from the internal combustion engine is transmitted from the first helical gear 14 to the second helical gear 16, the thrust acting on the first helical gear 14 is in the same direction as the direction in which the first shaft 13 extends from the wheel hub 22.

[0066] [Second axis]

[0067] The second shaft 15 extends along the first shaft 13 . That is, the second shaft 15 extends in the axial direction. The second shaft 15 is arranged radially outward relative to the first shaft 13 .

[0068] [Second helical gear]

[0069] The second helical gear 16 is mounted on the second shaft 15. Specifically, the second helical gear 16 is fixed to the second shaft 15. The second helical gear 16 rotates integrally with the second shaft 15. Furthermore, the second helical gear 16 moves integrally with the second shaft 15 in the axial direction.

[0070] The second helical gear 16 meshes with the first helical gear 14. The second helical gear 16 has a smaller outer diameter than the first helical gear 14. That is, the first helical gear 14 has a larger outer diameter than the second helical gear 16.

[0071] [Electric motor]

[0072] The electric motor 17 is mounted on the second shaft 15. The electric motor 17 rotates integrally with the second shaft 15. When the internal combustion engine is started, the electric motor 17 outputs torque to rotate the internal combustion engine. When the electric motor 17 does not output torque, the electric motor 17 rotates using the torque from the internal combustion engine, functioning as a generator.

[0073] [action]

[0074] When torque from the internal combustion engine is transmitted, the flywheel 101 rotates and transmits the torque to the first shaft 13 and the first helical gear 14 via the torque limiting unit 12 and the damper unit 11. The damper unit 11 absorbs torque fluctuations caused by the internal combustion engine.

[0075] A thrust force acts in the first axial direction on the first helical gear 14. Therefore, a load in the first axial direction is applied to the flange plate 21 via the first shaft 13. Here, the first coil spring 7 is positioned on the second axial side relative to the flange plate 21. Therefore, no axial load due to the thrust force of the first helical gear 14 acts on the first coil spring 7. This reduces wear on the first coil spring 7 and extends its service life.

[0076] Furthermore, when the electric motor 17 is driven to start the internal combustion engine, the torque from the electric motor 17 is transmitted to the first helical gear 14 via the second shaft 15 and the second helical gear 16. The first helical gear 14 rotates in the rotational direction due to the torque from the second helical gear 16, and thus a thrust force in the second axial direction acts on the first helical gear 14.

[0077] In this manner, when torque is input from the electric motor 17, a thrust in the second axial direction acts on the first helical gear 14, thereby also applying a load in the second axial direction to the flange plate 21. Consequently, an axial load is applied to the first spiral spring 7, which is arranged on the second axial side relative to the flange plate 21. As a result, resonance, which is likely to occur when starting the internal combustion engine, can be more effectively suppressed.

[0078] [Variation]

[0079] The present invention is not limited to the above-described embodiment, and various modifications and corrections can be made without departing from the scope of the present invention. In addition, the following modifications can be applied simultaneously.

[0080] (a) In the above embodiment, the direction away from the hub 22 ( Figure 1 The first helical gear 14 is formed by the thrust acting on the right side of the gear. Figure 1 The right side of the first helical gear 14 becomes the first side in the axial direction, but the structure of the first helical gear 14 is not limited to this.

[0081] For example, Figure 3 As shown, when the first helical gear 14 is rotated in the rotation direction by the torque from the internal combustion engine, a thrust toward the hub 22 acts on the first helical gear 14. That is, Figure 1 The left side of the first helical gear 14 can also be the first axial side. The twisting direction of the first helical gear 14 is opposite to the rotational direction. That is, the first helical gear 14 twists in the direction opposite to the rotational direction. Furthermore, in this variation, the first helical gear 14 is torsionally counterclockwise. Consequently, the thrust acting on the first helical gear 14 is directed in the same direction as toward the wheel hub 22.

[0082] In this case, the first plate 31 and the first friction member 5 are arranged on the left side of the flange plate 21 , and the second plate 32 , the second friction member 6 , and the first coil spring 7 are arranged on the right side of the flange plate 21 .

[0083] (b) In the above embodiment, the power transmission device 100 includes the torque limiting unit 12 , but this is not limited to the configuration of the power transmission device 100 . For example, the power transmission device 100 may not include the torque limiting unit 12 .

Claims

1. A power transmission device, characterized in that: have: An output rotating body having a hub and a flange plate; an input rotating body having a first plate arranged on a first side in the axial direction relative to the flange plate and a second plate arranged on a second side in the axial direction relative to the flange plate; an elastic member elastically connecting the input rotating body and the output rotating body; a first shaft mounted on the wheel hub; a first helical gear fixed to the first shaft and configured to apply a thrust force toward a first side in the axial direction when rotating in the rotational direction; a second axis extending along the first axis; a second helical gear mounted on the second shaft and meshing with the first helical gear; as well as The force applying member is disposed between the flange plate and the second plate.

2. The power transmission device according to claim 1, wherein: The power transmission device further includes an electric motor mounted on the second shaft.

3. The power transmission device according to claim 1, wherein: The first shaft extends from the hub toward a first side in the axial direction. The first helical gear is configured so that, when rotating in a rotational direction, a thrust force acts in the direction in which the first shaft extends.

4. The power transmission device according to claim 1, wherein: The torsion direction of the first helical gear is the same as the rotation direction.

5. The power transmission device according to claim 1, wherein: The first helical gear has a larger outer diameter than the second helical gear.

6. The power transmission device according to claim 1, wherein: The power transmission device further includes a friction member disposed between the urging member and the flange plate. The urging member urges the friction member toward the flange plate.

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