Power transmission device and damper device

Abstract

To provide a power transmission device capable of improving performance.SOLUTION: The power transmission device includes a flywheel and a damper device. The damper device is attached to the flywheel. The damper device includes a first rotary member, a second rotary member, an elastic member and a fastening member. The first rotary member is configured to be unitarily rotated with the flywheel. The second rotary member is disposed to be rotatable relative to the first rotary member. The elastic member elastically couples the first rotary member and the second rotary member. The fastening member fastens the first rotary member to the outer peripheral end of the flywheel. The fastening member includes a head portion, a screw portion, and a rod portion. The rod portion is disposed between the head portion and the screw portion. The rod portion has a smaller diameter than the screw portion. The rod portion overlaps the second rotary member as viewed in the radial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power transmission device and a damper device. [Background technology]

[0002] A power transmission device is configured to absorb torque fluctuations of an internal combustion engine or the like. The power transmission device has a flywheel and a damper device (see Patent Document 1). The damper device is attached to the flywheel. The damper device has a drive member, a driven member, and an elastic member. The drive member rotates integrally with the flywheel. The elastic member elastically connects the drive member and the driven member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-53636 Summary of the Invention [Problem to be solved by the invention]

[0004] In the power transmission device configured as described above, there is a demand for improving the performance of the power transmission device by disposing the elastic member further radially outward. Therefore, an object of the present invention is to provide a power transmission device that can improve performance. [Means for solving the problem]

[0005] A power transmission device according to a first aspect includes a flywheel and a damper device. The damper device is attached to the flywheel. The damper device has a first rotating member, a second rotating member, an elastic member, and a fastening member. The first rotating member is configured to rotate integrally with the flywheel. The second rotating member is arranged to be rotatable relative to the first rotating member. The elastic member elastically connects the first rotating member and the second rotating member. The fastening member fastens the first rotating member to the outer peripheral end of the flywheel. The fastening member has a head, a threaded portion, and a rod portion. The rod portion is arranged between the head and the threaded portion. The rod portion has a smaller diameter than the threaded portion. The rod portion overlaps the second rotating member when viewed in the radial direction.

[0006] According to this configuration, the fastening member for fixing the first rotating member has a rod portion whose diameter is smaller than that of the threaded portion. This rod portion overlaps with the second rotating member in a radial view. This allows the second rotating member to be made larger in the radial direction, and thus allows the elastic member to be positioned radially outward. As a result, the performance of the power transmission device can be improved.

[0007] A power transmission device according to a second aspect is the power transmission device according to the first aspect, and is configured as follows: The second rotating member has a protruding portion that protrudes radially outward. The first rotating member has a stopper portion that faces the protruding portion in the circumferential direction. The rod portion is disposed radially outward relative to the outer peripheral surface of the protruding portion. A portion of the threaded portion is disposed radially inward relative to the outer peripheral surface of the protruding portion.

[0008] A power transmission device according to a third aspect is the power transmission device according to the first or second aspect, and is configured as follows: The flywheel has a disk portion and a first inertia portion. The first inertia portion protrudes in the axial direction from the outer peripheral end of the disk portion. The first inertia portion is annular. The first inertia portion has a recess. The recess extends in the axial direction and opens radially inward. The flywheel has a threaded hole. The threaded hole communicates with the recess in the axial direction. The fastening member extends axially within the recess. The threaded portion screws into the threaded hole.

[0009] A power transmission device according to a fourth aspect is the power transmission device according to the third aspect, and is configured as follows: The rod portion is disposed in the recess so as to be located radially outward from the inner circumferential surface of the first inertia portion, and a portion of the threaded portion is located radially inward from the inner circumferential surface of the first inertia portion.

[0010] A power transmission device according to a fifth aspect is the power transmission device according to the third or fourth aspect, and is configured as follows: The flywheel has a second inertia portion. The second inertia portion is disposed between the outer peripheral end of the disc portion and the first inertia portion. The inner diameter of the second inertia portion is smaller than the inner diameter of the first inertia portion.

[0011] A power transmission device according to a sixth aspect is the power transmission device according to the fifth aspect, and is configured as follows: The screw hole is formed in the second inertia portion.

[0012] A damper device according to a seventh aspect is configured to be attached to a flywheel. The damper device includes a first rotating member, a second rotating member, an elastic member, and a fastening member. The first rotating member is configured to rotate integrally with the flywheel. The second rotating member is arranged to be rotatable relative to the first rotating member. The elastic member elastically connects the first rotating member and the second rotating member. The fastening member fastens the first rotating member to the outer peripheral end of the flywheel. The fastening member has a head, a threaded portion, and a rod portion. The rod portion is arranged between the head and the threaded portion and has a smaller diameter than the threaded portion. The rod portion overlaps the second rotating member when viewed in the radial direction. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a power transmission device that can improve performance. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. [Figure 2]Cross-sectional view of line II-II in Figure 1. [Figure 3] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] The power transmission device 100 according to this embodiment will be described below with reference to the 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. 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.

[0016] FIG. 1 is a front view of a power transmission device 100 according to this embodiment, and FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. In FIG. 2, line OO is the rotation axis O of the power transmission device 100. Note that this line OO also corresponds to the rotation axis O of the damper device 20. In FIG. 2, an internal combustion engine is disposed on the left side of the power transmission device 100. Furthermore, an output side member such as a generator is disposed radially outward of the power transmission device 100. Note that an output side member such as a generator or a transmission may also be disposed on the right side of the power transmission device 100.

[0017] 1 and 2, the power transmission device 100 includes a flywheel 10 and a damper device 20. The flywheel 10 and the damper device 20 basically rotate integrally with each other.

[0018] [Flywheel] The flywheel 10 is disposed rotatably about a rotation axis O. The flywheel 10 is configured to be attached to, for example, the crankshaft of an internal combustion engine. The flywheel 10 has a disk portion 11, an inertia portion 12, and a plurality of knock pins 13. The disk portion 11 and the inertia portion 12 are integrally formed as a single member. Note that the disk portion 11 may be formed as a separate member from the inertia portion 12. In this case, the disk portion 11 may be a flexible plate.

[0019] The disk portion 11 is disk-shaped. The inertia portion 12 protrudes from the outer peripheral end of the flywheel 10 toward a first side in the axial direction. The inertia portion 12 is annular and extends in the circumferential direction.

[0020] The inertia portion 12 has a first inertia portion 121 and a second inertia portion 122. The first inertia portion 121 and the second inertia portion 122 are annular. The first inertia portion 121 and the second inertia portion 122 are integrally formed as a single member.

[0021] The first inertia portion 121 protrudes from the outer circumferential end of the disc portion 11 toward a first side in the axial direction. The second inertia portion 122 is disposed between the outer circumferential end of the disc portion 11 and the first inertia portion 121. In detail, the second inertia portion 122 protrudes from the outer circumferential end of the disc portion 11 toward the first side in the axial direction, and the first inertia portion 121 protrudes from the second inertia portion 122 toward the first side in the axial direction.

[0022] The inner diameter of the second inertia portion 122 is smaller than the inner diameter of the first inertia portion 121. The outer diameter of the second inertia portion 122 is approximately the same as the outer diameter of the first inertia portion 121. The outer diameter of the second inertia portion 122 is approximately the same as the outer diameter of the disc portion 11. When viewed in the radial direction, the first inertia portion 121 overlaps with the second rotating member 22, which will be described later.

[0023] The first inertia portion 121 has a plurality of recesses 123. The recesses 123 are arranged in the circumferential direction. Each recess 123 extends in the axial direction. Each recess 123 penetrates the first inertia portion 121 in the axial direction. Each recess 123 opens radially inward. That is, each recess 123 is formed by recessing a portion of the inner circumferential surface 126 of the first inertia portion 121 radially outward.

[0024] The second inertia portion 122 has a plurality of screw holes 124. The number of screw holes 124 is the same as the number of recesses 123. Each screw hole 124 communicates with a corresponding recess 123 in the axial direction.

[0025] The multiple knock pins 13 are arranged in the circumferential direction. The knock pins 13 extend in the axial direction. Specifically, the knock pins 13 protrude from the first inertia portion 121 to a first axial side. The knock pins 13 are fitted into fitting holes 125 formed in the first inertia portion 121. The damper device 20 is positioned relative to the flywheel 10 by inserting the knock pins 13 into positioning holes 216 formed in the outer circumferential end of the damper device 20.

[0026] [Damper device] The damper device 20 is provided between the flywheel 10 and an input shaft (not shown) of an output side member. The damper device 20 is configured to damp fluctuations in torque transmitted between the internal combustion engine and the output side member.

[0027] The damper device 20 is disposed on a first axial side of the flywheel 10. Specifically, the damper device 20 is disposed radially inside the inertia portion 12. The damper device 20 is disposed so as to be surrounded by the inertia portion 12.

[0028] The damper device 20 is attached to the flywheel 10. More specifically, the damper device 20 is attached to the inertia portion 12 of the flywheel 10 at its outer peripheral end.

[0029] The damper device 20 includes a first rotating member 21, a second rotating member 22, a plurality of elastic members 23, and a plurality of fastening members 24.

[0030] <First rotating member> The first rotating member 21 is configured to rotate integrally with the flywheel 10. The first rotating member 21 is fastened to the flywheel 10 by fastening members 24. The first rotating member 21 has a first plate 211 and a second plate 212.

[0031] The first plate 211 and the second plate 212 are both annular members having a center hole. The first plate 211 and the second plate 212 are arranged at an interval from each other in the axial direction. The second plate 212 is arranged on the second side in the axial direction with respect to the first plate 211. In other words, the second plate 212 is arranged between the flywheel 10 and the first plate 211 in the axial direction. The first plate 211 and the second plate 212 are configured to rotate integrally with each other. Furthermore, the first plate 211 and the second plate 212 are immovable relative to each other in the axial direction.

[0032] The first plate 211 has a plurality of first window portions 213. The first window portions 213 are arranged in the circumferential direction. The second plate 212 has a plurality of second window portions 214. The second window portions 214 are arranged in the circumferential direction. The second window portions 214 are arranged in positions that overlap with the first window portions 213 when viewed in the axial direction.

[0033] The first plate 211 is fixed to the flywheel 10. In detail, the first rotating member 21 has a flexible plate 215. The flexible plate 215 is fixed to the first plate 211. The first plate 211 is fixed to the flywheel 10 via the flexible plate 215. Note that the first plate 211 may be fixed directly to the flywheel 10.

[0034] The first rotating member 21 has a plurality of positioning holes 216 at its outer circumferential end. Each positioning hole 216 is formed in the flexible plate 215. Each knock pin 13 is fitted into each positioning hole 216.

[0035] The second plate 212 overlaps with the inertia portion 12 when viewed in the radial direction. The second plate 212 has a second plate main body 217, a plurality of stopper portions 218, and a plurality of attachment portions 219.

[0036] The second plate main body 217 is annular. Each stopper portion 218 extends from the outer peripheral end of the second plate main body 217 toward a first side in the axial direction. That is, each stopper portion 218 extends in the axial direction from the second plate main body 217 toward the first plate 211. The stopper portions 218 are arranged at intervals from one another in the circumferential direction. Each stopper portion 218 faces a protrusion 224, which will be described later, in the circumferential direction.

[0037] Each mounting portion 219 extends radially inward from the stopper portion 218. More specifically, each mounting portion 219 extends radially inward from a first axial side end portion of the stopper portion 218. The mounting portions 219 are arranged at intervals in the circumferential direction.

[0038] The first plate 211 and the second plate 212 are fastened together by a rivet 101. More specifically, the rivet 101 fastens the first plate 211 to the attachment portion 219 of the second plate 212. The rivet 101 also fastens the flexible plate 215 to the first plate 211.

[0039] <Second rotating member> The second rotating member 22 is configured to transmit torque from the first rotating member 21 to the output side member. The second rotating member 22 is arranged to be rotatable relative to the first rotating member 21. The second rotating member 22 is arranged axially between the flywheel 10 and the first plate 211. The second rotating member 22 is arranged radially inward with respect to the inertia portion 12. More specifically, the second rotating member 22 is arranged radially inward with respect to the first inertia portion 121. When viewed radially, the second rotating member 22 overlaps with the first inertia portion 121. That is, the outer peripheral surface of the second rotating member 22 faces the inner peripheral surface 126 of the first inertia portion 121. The first inertia portion 121 is arranged to surround the second rotating member 22.

[0040] The second rotating member 22 has a boss portion 221, a flange portion 222, and a plurality of receiving holes 223. The boss portion 221 and the flange portion 222 may be formed of separate members, or may be formed integrally as a single member. The boss portion 221 and the flange portion 222 rotate approximately integrally.

[0041] The boss portion 221 is cylindrical and extends in the axial direction. The boss portion 221 is disposed within the central holes of the first plate 211 and the second plate 212. A spline hole extending in the axial direction is formed in the inner periphery of the boss portion 221. An input shaft (not shown) of an output side member can be spline-engaged with this spline hole.

[0042] The flange portion 222 extends radially outward from the outer peripheral surface of the boss portion 221. The flange portion 222 is annular and extends in the circumferential direction. When the flange portion 222 is formed as a separate member from the boss portion 221, the flange portion 222 has a plurality of internal teeth, and the boss portion 221 has external teeth. The internal teeth of the flange portion 222 mesh with the external teeth of the boss portion 221. Therefore, the flange portion 222 rotates integrally with the boss portion 221. The flange portion 222 is disposed between the first plate 211 and the second plate 212 in the axial direction.

[0043] The accommodating holes 223 are formed in the flange portion 222. The accommodating holes 223 are arranged in a row in the circumferential direction. When viewed in the axial direction, the accommodating holes 223 are arranged at positions overlapping with the first window portions 213 and the second window portions 214.

[0044] The second rotating member 22 has a plurality of protruding portions 224. Each protruding portion 224 protrudes radially outward. Specifically, each protruding portion 224 protrudes radially outward from the flange portion 222. The protruding portions 224 are arranged between pairs of adjacent stopper portions 218 in the circumferential direction. That is, the protruding portions 224 and the stopper portions 218 are arranged alternately in the circumferential direction. The protruding portions 224 come into contact with the stopper portions 218, thereby restricting the relative rotation angle between the first rotating member 21 and the second rotating member 22. Each protruding portion 224 and each stopper portion 218 constitute a stopper mechanism.

[0045] <Elastic material> Each elastic member 23 is configured to elastically connect in the rotational direction the first rotary member 21 and the second rotary member 22. Each elastic member 23 is, for example, a coil spring.

[0046] The elastic member 23 is housed in the housing hole 223 of the flange portion 222. The elastic member 23 is housed in the first window portion 213 of the first plate 211 and also in the second window portion 214 of the second plate 212.

[0047] <Fastening components> Each fastening member 24 fastens the first rotating member 21 to the outer peripheral end of the flywheel 10. More specifically, each fastening member 24 fastens the first plate 211 to the flywheel 10 via a flexible plate 215. Note that each fastening member 24 may fasten the first plate 211 directly to the flywheel 10 without using the flexible plate 215. Each fastening member 24 extends in the axial direction.

[0048] 3, each fastening member 24 has a head 241, a threaded portion 242, and a rod portion 243. The threaded portion 242 is a portion of the shaft extending from the head 241 where a screw thread is formed. The threaded portion 242 is disposed at a distance from the head 241 in the axial direction. The threaded portion 242 is threadedly engaged with the screw hole 124. The threaded portion 242 does not face the outer peripheral surface of the second rotating member 22. In other words, the threaded portion 242 does not face the outer peripheral surface of the flange portion 222 in the radial direction.

[0049] The rod portion 243 is a non-threaded portion of the shaft extending from the head portion 241. The rod portion 243 is disposed between the head portion 241 and the threaded portion 242 in the axial direction.

[0050] The rod portion 243 has a smaller diameter than the threaded portion 242. For example, the diameter of the rod portion 243 is smaller than the diameter of the threaded portion 242 by the amount of the screw thread. The rod portion 243 overlaps with the second rotating member 22 when viewed in the radial direction. More specifically, the rod portion 243 overlaps with the flange portion 222 when viewed in the radial direction. That is, the rod portion 243 faces the outer circumferential surface of the flange portion 222 in the radial direction.

[0051] The rod portion 243 is disposed radially outward relative to the outer circumferential surface of the protruding portion 224. Therefore, when the second rotating member 22 rotates relative to the first rotating member 21 and the flywheel 10, the rod portion 243 does not come into contact with the protruding portion 224. The outer circumferential surface of the protruding portion 224 refers to the surface of the protruding portion 224 that faces radially outward.

[0052] On the other hand, a portion of the threaded portion 242 is disposed radially inward relative to the outer peripheral surface of the protruding portion 224. The threaded portion 242 is disposed on the second axial side relative to the protruding portion 224. In other words, the threaded portion 242 does not overlap with the flange portion 222 of the second rotating member 22 when viewed in the radial direction. Therefore, when the second rotating member 22 rotates relative to the first rotating member 21, the threaded portion 242 does not come into contact with the protruding portion 224.

[0053] The fastening member 24 extends in the axial direction within the recess 123 and is threadedly engaged with the screw hole 124. More specifically, the rod portion 243 is disposed within the recess 123, and the screw portion 242 is threadedly engaged with the screw hole 124. The rod portion 243 is disposed radially outward from the inner circumferential surface 126 of the first inertia portion 121. In other words, the rod portion 243 is housed within the recess 123 and does not protrude radially inward from the recess 123. On the other hand, a portion of the screw portion 242 is disposed radially inward from the inner circumferential surface 126 of the first inertia portion 121.

[0054] [Variations] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and various modifications are possible without departing from the spirit of the present invention. Note that the following modifications can basically be applied simultaneously.

[0055] (a) In the above embodiment, the first rotating member 21 has the first plate 211 and the second plate 212, but the configuration of the first rotating member 21 is not limited to this. For example, the first rotating member 21 does not have to have the second plate 212.

[0056] (b) In the above embodiment, the screw holes 124 are formed in the second inertia portion 122, but the screw holes 124 may be formed in the disk portion 11.

[0057] (c) In the above embodiment, the inertia portion 12 has the first inertia portion 121 and the second inertia portion 122, but the configuration of the inertia portion 12 is not limited to this. For example, the inertia portion 12 does not have to have the second inertia portion 122. In other words, the first inertia portion 121 may be formed directly on the outer circumferential end of the disk portion 11. In this case, the screw hole 124 is formed in the disk portion 11. [Explanation of symbols]

[0058] 10: Flywheel 11: Disc part 12: Inertia section 121: First inertia section 122: Second inertia section 123: Recess 124: Screw hole 126: Inner surface 20: Damper device 21: First rotating member 218: Stopper part 22: Second rotating member 224:Protrusion 23: Elastic member 24: Fastening member 241:Head 242: Threaded part 243: Rod part 100: Power transmission device

Claims

1. A flywheel and a damper device attached to the flywheel; Equipped with The damper device is a first rotating member configured to rotate integrally with the flywheel; a second rotating member arranged to be rotatable relative to the first rotating member; an elastic member that elastically connects the first rotary member and the second rotary member; a fastening member that fastens the first rotary member to an outer peripheral end of the flywheel; and the fastening member has a head, a threaded portion, and a rod portion disposed between the head and the threaded portion; The rod portion has a diameter smaller than that of the threaded portion and overlaps with the second rotating member when viewed in a radial direction. Power transmission device.

2. the second rotating member has a protruding portion that protrudes radially outward, the first rotating member has a stopper portion that faces the protruding portion in the circumferential direction, the rod portion is disposed radially outward relative to an outer circumferential surface of the protrusion, a part of the threaded portion is disposed radially inward with respect to an outer circumferential surface of the protruding portion; The power transmission device according to claim 1 .

3. the flywheel has a disk portion and an annular first inertia portion protruding in the axial direction from an outer peripheral end of the disk portion, the first inertia portion has a recess extending in the axial direction and opening radially inward, the flywheel has a screw hole that communicates with the recess in the axial direction, The fastening member extends axially within the recess, The screw portion is screwed into the screw hole. The power transmission device according to claim 1 .

4. the rod portion is disposed in the recess so as to be disposed radially outward with respect to an inner circumferential surface of the first inertia portion, a portion of the threaded portion is disposed radially inward with respect to an inner circumferential surface of the first inertia portion; The power transmission device according to claim 3 .

5. the flywheel has a second inertia portion disposed between an outer peripheral end of the disk portion and the first inertia portion, an inner diameter of the second inertia portion is smaller than an inner diameter of the first inertia portion; The power transmission device according to claim 3 .

6. the screw hole is formed in the second inertia portion, The power transmission device according to claim 5 .

7. A damper device configured to be attached to a flywheel, a first rotating member configured to rotate integrally with the flywheel; a second rotating member arranged to be rotatable relative to the first rotating member; an elastic member that elastically connects the first rotary member and the second rotary member; a fastening member that fastens the first rotary member to an outer peripheral end of the flywheel; Equipped with the fastening member has a head, a threaded portion, and a rod portion disposed between the head and the threaded portion; The rod portion has a diameter smaller than that of the threaded portion and overlaps with the second rotating member when viewed in a radial direction. Damper device.

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