Power transmission device

Abstract

To provide a power transmission device that can be made low-cost. [Solution] The power transmission device comprises a flexible plate and a drive plate. The flexible plate is configured to receive torque from the prime mover. The drive plate is configured to rotate integrally with the flexible plate. The flexible plate has a protrusion that projects axially toward the drive plate. The drive plate is annular. The inner circumferential end of the drive plate is positioned radially inward relative to the protrusion. The drive plate is thicker than the flexible plate.

Description

Technical Field

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

Background Art

[0002] The power transmission device disclosed in Patent Document 1 has a flywheel, a torque limiter, and a damper unit. The flywheel has a flexible plate and an inertia ring. The torque limiter is attached to the inertia ring.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a power transmission device capable of cost reduction.

Means for Solving the Problems

[0005] The power transmission device according to the first aspect includes a flexible plate and a drive plate. The flexible plate is configured to receive torque from the prime mover. The drive plate is configured to rotate integrally with the flexible plate. The flexible plate has a convex portion that protrudes axially toward the drive plate. The drive plate is annular. The inner peripheral end of the drive plate is disposed radially inward with respect to the convex portion. The drive plate has a greater plate thickness than the flexible plate.

[0006] In this configuration, a drive plate having a thicker plate thickness than the flexible plate is attached to the flexible plate, allowing this drive plate to function as at least part of the inertial ring. Therefore, at least part of the inertial ring can be omitted. Inertial rings are generally formed by casting, while drive plates are generally formed by sheet metal processing or press working of a metal plate. Here, a drive plate formed by sheet metal processing or press working is cheaper than an inertial ring formed by casting. Therefore, the power transmission device can be made less expensive. In addition, although the drive plate has lower rigidity than the inertial ring, its rigidity can be improved by extending the inner circumference of the drive plate radially inward relative to the convex portion of the flexible plate.

[0007] The power transmission device according to the second embodiment further comprises a disc spring in addition to the power transmission device according to the first embodiment. The disc spring is arranged in the axial direction between the flexible plate and the drive plate. The disc spring contacts the convex portion and the drive plate.

[0008] The power transmission device according to the third embodiment is configured as follows in the power transmission device according to the second embodiment: The disc spring contacts the drive plate at its outer circumference and contacts the convex portion at its inner circumference.

[0009] The power transmission device according to the fourth embodiment is configured as follows in the power transmission device according to the second embodiment: The disc spring contacts the convex portion at its outer peripheral end and contacts the drive plate at its inner peripheral end.

[0010] The power transmission device according to the fifth embodiment is configured as follows in the power transmission device according to the first embodiment: The drive plate is in contact with the protrusion.

[0011] The power transmission device according to the sixth embodiment is configured as follows in the power transmission device according to any of the first to fifth embodiments: The drive plate has an annular portion and a cylindrical portion. The annular portion extends in the circumferential direction. The cylindrical portion extends axially from the outer peripheral end of the annular portion.

[0012] The power transmission device according to the seventh embodiment further comprises an inertia member in the power transmission device according to any of the first to sixth embodiments. The inertia member is configured to rotate integrally with the flexible plate and the drive plate.

[0013] The power transmission device according to the eighth embodiment further comprises a torque limiter in addition to the power transmission device according to any of the first to seventh embodiments. The torque limiter is mounted on a flexible plate.

[0014] The power transmission device according to the ninth embodiment is configured as follows in the power transmission device according to the eighth embodiment: The torque limiter has a first side plate, a friction plate, a pressure plate, and a biasing member. The first side plate is attached to a flexible plate. The friction plate is arranged to be rotatable relative to the first side plate. The pressure plate cooperates with the first side plate to clamp the friction plate. The biasing member biases the pressure plate axially toward the first side plate.

[0015] The power transmission device according to the 10th embodiment is configured as follows in the power transmission device according to the 9th embodiment: The first side plate has an annular portion and a cylindrical portion. The annular portion extends in the circumferential direction. The cylindrical portion extends axially from the outer peripheral end of the annular portion toward the flexible plate.

[0016] The power transmission device according to the 11th embodiment is configured as follows in the power transmission device according to the 10th embodiment. The cylindrical portion constitutes the outer circumferential surface of the power transmission device.

[0017] The power transmission device according to the 12th aspect is configured as follows in the power transmission device according to the 10th or 11th aspect. The flexible plate abuts against the inner peripheral surface of the cylindrical portion.

[0018] The power transmission device according to the 13th aspect further includes a damper unit in the power transmission device according to any one of the 1st to 12th aspects. The damper unit is attached to the flexible plate. The damper unit has a first rotating member, a second rotating member, and an elastic member. The first rotating member receives torque from the flexible plate. The second rotating member is arranged to be relatively rotatable with respect to the first rotating member. The elastic member elastically connects the first rotating member and the second rotating member.

Advantages of the Invention

[0019] According to the present invention, the cost of the power transmission device can be reduced.

Brief Description of the Drawings

[0020] [Figure 1] Cross-sectional view of the power transmission device. [Figure 2] Plan view of the power transmission device with the torque limiter and the damper unit removed. [Figure 3] Enlarged cross-sectional view of the power transmission device. [Figure 4] Enlarged cross-sectional view of the power transmission device. [Figure 5] Cross-sectional view of the power transmission device according to the modification. [Figure 6] Cross-sectional view of the power transmission device according to the modification.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, the power transmission device 100 according to the present embodiment will be described while referring to the drawings. In the following description, the axial direction is the direction in which the rotation axis O of the power transmission device 100 extends. The circumferential direction is the circumferential direction of a circle centered on the rotation axis O, and the radial direction is the radial direction of a circle centered on the rotation axis O. The first axial side means the right side in FIG. 1, and the second axial side means the left side in FIG. 1.

[0022] FIG. 1 is a cross-sectional view of the power transmission device 100. As shown in FIG. 1, the power transmission device 100 includes a flexible plate 2, a drive plate 3, a disc spring 4, a plurality of inertia blocks 5 (an example of an inertia member), a torque limiter 6, and a damper unit 7. The flexible plate 2, the drive plate 3, the disc spring 4, the inertia block 5, and the torque limiter 6 are configured to rotate integrally with each other. The torque limiter 6 and the damper unit 7 are relatively rotatable, but basically rotate integrally with each other. When the torque transmitted to the power transmission device 100 exceeds a predetermined value, the torque limiter 6 and the damper unit 7 rotate relative to each other.

[0023] The power transmission device 100 is provided between a prime mover (not shown) and an output side member (not shown). The prime mover is, for example, an internal combustion engine. The output side member is, for example, an electric motor or a transmission. The internal combustion engine is disposed on the second axial side (the left side in FIG. 1) with respect to the power transmission device 100, and the output side member is disposed on the first axial side (the right side in FIG. 1) with respect to 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.

[0024] [Flexible Plate] The flexible plate 2 is configured to receive torque from the prime mover. Specifically, the flexible plate 2 is attached to the crankshaft 102 by a plurality of bolts 101.

[0025] The flexible plate 2 is disc-shaped. The flexible plate 2 is flexible. The flexible plate 2 can be made of steel sheet or the like, specifically SPCC (cold-rolled steel sheet), SPHC (hot-rolled steel sheet), or SAPH (hot-rolled steel sheet for automotive structural use). The thickness of the flexible plate 2 is, for example, about 2 to 4 mm. Although not particularly limited, for example, during the operation of the power transmission device 100, the flexible plate 2 can bend about 0.3 to 0.5 mm in the axial direction.

[0026] The flexible plate 2 has a protrusion 21. The protrusion 21 projects axially to the first side. That is, the protrusion 21 projects toward the drive plate 3. The protrusion 21 is annular in shape and extends in the circumferential direction.

[0027] [Drive Plate] The drive plate 3 is positioned on the first axial side relative to the flexible plate 2. The drive plate 3 is configured to rotate integrally with the flexible plate 2. Specifically, the drive plate 3 is fastened to the flexible plate 2 by bolts 103 that screw into the inertia block 5. Each bolt 103 is arranged at equal intervals from one another in the circumferential direction.

[0028] The drive plate 3 is annular in shape. The inner circumferential end of the drive plate 3 is positioned radially inward relative to the protrusion 21 of the flexible plate 2. The thickness of the drive plate 3 is greater than that of the flexible plate 2. Unlike the flexible plate 2, the drive plate 3 is not flexible. That is, the drive plate 3 does not fundamentally flex during the operation of the power transmission device 100. The thickness of the drive plate 3 can be, for example, about 5 to 7 mm.

[0029] The drive plate 3 can be formed from a steel sheet, specifically from SPCC (cold-rolled steel sheet), SPHC (hot-rolled steel sheet), or SAPH (hot-rolled steel sheet for automotive structural use). The drive plate 3 can be formed by sheet metal processing or press working of the steel sheet. Specifically, the drive plate 3 can be formed by a single-stroke press, a progressive press, or a transfer press.

[0030] The drive plate 3 has a first annular portion 31 and a first cylindrical portion 32. The first annular portion 31 is an annular shape extending in the circumferential direction. The outer circumference of the first annular portion 31 is in contact with the flexible plate 2 in the axial direction. The inner circumference of the first annular portion 31 is spaced apart from the flexible plate 2 in the axial direction. The first annular portion 31 has a stepped portion 33.

[0031] The first cylindrical portion 32 extends from the outer peripheral end of the first annular portion 31 toward the first axial direction. That is, the first cylindrical portion 32 extends from the outer peripheral end of the first annular portion 31 toward the torque limiter 6. The first cylindrical portion 32 is formed by bending the outer peripheral portion of the drive plate 3. For this reason, the first cylindrical portion 32 has substantially the same plate thickness as the first annular portion 31. In a radial view, the first cylindrical portion 32 overlaps with the inertia block 5.

[0032] [Disc spring] The disc spring 4 is positioned axially between the flexible plate 2 and the drive plate 3. The disc spring 4 is in contact with the protrusion 21 of the flexible plate 2 and the drive plate 3. Specifically, the outer peripheral end 41 of the disc spring 4 is in contact with the drive plate 3. On the other hand, the inner peripheral end 42 of the disc spring 4 is in contact with the protrusion 21 of the flexible plate 2. When the power transmission device 100 is not operating, the outer peripheral end 41 of the disc spring 4 is not in contact with the flexible plate 2, and the inner peripheral end 42 of the disc spring 4 is not in contact with the drive plate 3.

[0033] The disc spring 4 is positioned between the flexible plate 2 and the drive plate 3 in a compressed state. The outer surface of the disc spring 4 is in contact with the stepped portion 33 of the drive plate 3. This restricts the radial movement of the disc spring 4.

[0034] Because the disc spring 4 is in contact with the protrusion 21 in this manner, when the flexible plate 2 is deflected in the axial direction during the operation of the power transmission device 100, the protrusion 21 slides against the disc spring 4, thereby suppressing resonance.

[0035] [Inertia Block] Figure 2 is a plan view of the power transmission device 100 with the torque limiter 6 and damper unit 7 removed. As shown in Figures 1 and 2, the inertia blocks 5 are positioned on the first axial side relative to the drive plate 3. Each inertia block 5 is spaced apart from the others in the circumferential direction. Each inertia block 5 is positioned on the same circumference.

[0036] The inertia block 5 is configured to rotate integrally with the flexible plate 2 and the drive plate 3. Specifically, the inertia block 5 comprises a plurality of first inertia blocks 5a and a plurality of inertia blocks 5b. The inertia block 5 has a screw hole 51. The screw hole 51 penetrates axially. In detail, the first inertia block 5a has two screw holes 51, and the second inertia block 5b has one screw hole 51. The first inertia blocks 5a and the second inertia blocks 5b are arranged alternately in the circumferential direction.

[0037] The first inertia block 5a and the second inertia block 5b are fixed to the drive plate 3 by bolts 103. Specifically, the inertia block 5 is fixed to the drive plate 3 by screwing the bolts 103 into the screw holes 51 of the inertia block 5. In the first inertia block 5a, the bolt 103 is screwed into one of the two screw holes 51. The inertia block 5 may also be fixed to the drive plate 3 by welding. The inertia block 5 is fixed to the outer circumference of the drive plate 3.

[0038] In a radial view, the inertia block 5 overlaps with the first cylindrical portion 32 and the second cylindrical portion 612. More specifically, the inertia block 5 faces the inner circumferential surface of the first cylindrical portion 32. In an axial view, the inertia block 5 overlaps with the first annular portion 31 and the second annular portion 611. More specifically, in an axial view, the inertia block 5 overlaps with the outer circumferential portion of the first annular portion 31 and the first outer circumferential portion 611b of the second annular portion 611.

[0039] The inertia block 5 is positioned axially between the drive plate 3 and the first side plate 61. More specifically, the inertia block 5 is sandwiched axially between the drive plate 3 and the second side plate 62. More specifically, the inertia block 5 is sandwiched axially between the first annular portion 31 and the second outer peripheral portion 622.

[0040] The inertia block 5 is, for example, a nut. The inertia block 5 is thicker than the thickness of the first side plate 61. Also, the inertia block 5 is thicker than the thickness of the drive plate 3. Note that the thickness of the inertia block 5 refers to the axial dimension.

[0041] [torque limiter] The torque limiter 6 is rotatably positioned around the rotation axis O. The torque limiter 6 is positioned on the first axial side relative to the drive plate 3. The torque limiter 6 is annular in shape. The torque limiter 6 is configured to be mounted on the flexible plate 2. In detail, the torque limiter 6 is mounted on the flexible plate 2 via the inertia block 5 and the drive plate 3.

[0042] Figure 3 is an enlarged cross-sectional view of the power transmission device 100 cut at the location of the bolt 104 that fastens the torque limiter 6. As shown in Figure 3, the torque limiter 6 is attached to the inertia block 5 by the bolt 104 being screwed into the screw hole 51 of the first inertia block 5a. That is, of the two screw holes 51 of the first inertia block 5a, a bolt 103 for fastening the drive plate 3 is screwed into one screw hole 51, and a bolt 104 for fastening the torque limiter 6 is screwed into the other screw hole 51. Also, the bolt 104 is not screwed into the second inertia block 5b. That is, the drive plate 3 and the torque limiter 6 are fixed to the first inertia block 5a, and the drive plate 3 is fixed to the second inertia block 5b. There are more bolts 103 fastening the drive plate 3 than bolts 104 fastening the torque limiter 6. Each bolt 104 is arranged at equal intervals in the circumferential direction.

[0043] The torque limiter 6 is configured to limit the torque transmitted between the flexible plate 2 and the damper unit 7. In other words, the torque limiter 6 is configured to restrict the transmission of torque exceeding a predetermined value in the power transmission device 100. The torque limiter 6 is positioned radially outward relative to the damper unit 7.

[0044] Figure 4 is an enlarged cross-sectional view of the power transmission device. As shown in Figure 4, the torque limiter 6 has a first side plate 61, a second side plate 62, a friction plate 63, a pressure plate 64, and a biasing member 65.

[0045] <First side plate> The first side plate 61 is positioned on the first axial side relative to the drive plate 3. The first side plate 61 is attached to the flexible plate 2. Specifically, the first side plate 61 is attached to the flexible plate 2 via the drive plate 3 and the inertia block 5, which are fixed to the flexible plate 2.

[0046] The first side plate 61 and the second side plate 62 are fixed to the first inertia block 5a by screwing the bolt 104 into the threaded hole 51 of the first inertia block 5a. The first side plate 61 is annular in shape.

[0047] The first side plate 61 has a second annular portion 611 and a second cylindrical portion 612. The second annular portion 611 and the second cylindrical portion 612 are integrally formed from a single component.

[0048] The second annular portion 611 is an annular shape extending in the circumferential direction. The second annular portion 611 has a first inner circumferential portion 611a and a first outer circumferential portion 611b. The first inner circumferential portion 611a is in contact with the friction plate 63. The first inner circumferential portion 611a is positioned on the first axial side relative to the first outer circumferential portion 611b. The first outer circumferential portion 611b is positioned radially outward relative to the first inner circumferential portion 611a. In an axial view, the first outer circumferential portion 611b overlaps with the inertia block 5.

[0049] The second annular portion 611 has an annular recess 611c that extends in the circumferential direction. The recess 611c is recessed away from the drive plate 3. That is, the recess 611c is recessed on the first axial side. In an axial view, the recess 611c faces the first cylindrical portion 32. The tip of the first cylindrical portion 32 is located within this recess 611c.

[0050] The second cylindrical portion 612 extends axially from the outer peripheral end of the second annular portion 611. More specifically, the second cylindrical portion 612 extends axially to the second side from the outer peripheral end of the second annular portion 611. That is, the second cylindrical portion 612 extends axially from the outer peripheral end of the second annular portion 611 toward the flexible plate 2.

[0051] The second cylindrical portion 612 is positioned radially outward relative to the first cylindrical portion 32. In a radial view, the second cylindrical portion 612 overlaps with the first cylindrical portion 32. The second cylindrical portion 612 is longer than the first cylindrical portion 32. The second cylindrical portion 612 covers the entire outer circumferential surface of the first cylindrical portion 32. The second cylindrical portion 612 constitutes the outer circumferential surface of the power transmission device 100. In the axial direction, the second cylindrical portion 612 extends to the position of the flexible plate 2. The outer circumferential surface of the flexible plate 2 is in contact with the inner circumferential surface of the second cylindrical portion 612.

[0052] The second cylindrical portion 612 is formed by bending the outer circumference of the first side plate 61 toward the second axial direction. Therefore, the second cylindrical portion 612 has substantially the same thickness as the second annular portion 611. The thickness of the first side plate 61 can be, for example, about 2.0 to 8.0 mm.

[0053] The first side plate 61 can be formed from a steel sheet, specifically from SPCC (cold-rolled steel sheet), SPHC (hot-rolled steel sheet), or SAPH (hot-rolled steel sheet for automotive structural use). The first side plate 61 can be formed by sheet metal processing or press working of a steel sheet. Specifically, the first side plate 61 can be formed by single-stroke pressing, progressive pressing, or transfer pressing.

[0054] <Second side plate> The second side plate 62 is positioned on the second axial side relative to the first side plate 61. That is, the second side plate 62 is positioned axially between the drive plate 3 and the first side plate 61. More specifically, the second side plate 62 is positioned within the space defined by the first annular portion 31, the first cylindrical portion 32, and the second annular portion 611.

[0055] A friction plate 63, a pressure plate 64, and a biasing member 65 are positioned axially between the first side plate 61 and the second side plate 62. The thickness of the second side plate 62 is thinner than the thickness of the first side plate 61.

[0056] The second side plate 62 is configured to rotate integrally with the first side plate 61. The second side plate 62 is fastened to the first side plate 61 by a plurality of fastening members 66 (see Figure 1). Each fastening member 66 is spaced apart in the circumferential direction. The fastening members 66 are, for example, rivets or bolts. The first side plate 61 and the second side plate 62, fastened together by the fastening members 66, are fixed to the first inertia block 5a by bolts 104.

[0057] The second side plate 62 has a second inner circumference 621 and a second outer circumference 622. The second inner circumference 621 supports the biasing member 65. The second inner circumference 621 is positioned on the second axial side relative to the second outer circumference 622. The second inner circumference 621 is positioned at a distance from the first inner circumference 611a in the axial direction. The friction plate 63, pressure plate 64, and biasing member 65 are positioned between the first inner circumference 611a and the second inner circumference 621 in the axial direction.

[0058] The second outer circumference 622 is positioned radially outward relative to the second inner circumference 621. The second outer circumference 622 is in contact with the first outer circumference 611b in the axial direction. The second outer circumference 622 is sandwiched in the axial direction between the first outer circumference 611b and the inertia block 5. Another member may be interposed between the inertia block 5 and the second outer circumference 622.

[0059] The outer circumferential surface of the second side plate 62 faces the inner circumferential surface of the first cylindrical portion 32. The outer circumferential surface of the second side plate 62 may be in contact with the inner circumferential surface of the first cylindrical portion 32, or it may be positioned with a gap between them.

[0060] <Friction Plate> As shown in Figures 1 and 4, the friction plate 63 is an annular plate extending in the circumferential direction. The friction plate 63 is rotatably positioned around the axis of rotation O. The friction plate 63 is rotatably positioned relative to the first side plate 61.

[0061] The friction plate 63 is in contact with the first side plate 61 in the axial direction. More specifically, the friction plate 63 is in contact with the first inner circumference 611a of the second annular portion 611 in the axial direction. More specifically, the friction plate 63 is in contact with the first friction material 67a attached to the first side plate 61. The first friction material 67a rotates integrally with the first side plate 61. The first friction material 67a may be attached to the friction plate 63. The friction plate 63 is configured to frictionally engage with the first side plate 61.

[0062] The friction plate 63 is attached to the first rotating member 71 of the damper unit 7, which will be described later. More specifically, the friction plate 63 is attached to the second plate 71b. For example, the friction plate 63 is attached to the second plate 71b by a plurality of fastening members 105. The friction plate 63 rotates integrally with the first rotating member 71. Although the friction plate 63 is a separate component from the second plate 71b, the friction plate 63 may be integrally constructed with the second plate 71b as a single component.

[0063] <Pressure Plate> The pressure plate 64 is annular in shape. The pressure plate 64 is positioned axially between the biasing member 65 and the friction plate 63. The pressure plate 64 cooperates with the first side plate 61 to clamp the friction plate 63.

[0064] The pressure plate 64 is configured to rotate integrally with the first side plate 61. The pressure plate 64 is also axially movable relative to the first side plate 61. Specifically, the pressure plate 64 has a plurality of protrusions 641 that project radially outward. These protrusions 641 engage with engagement holes formed in the second side plate 62, so that the pressure plate 64 rotates integrally with the second side plate 62 while being axially movable relative to the second side plate 62. Since the second side plate 62 rotates integrally with the first side plate 61 and is not axially movable relative to the first side plate 61, the pressure plate 64 rotates integrally with the first side plate 61 and is axially movable relative to the first side plate 61.

[0065] The pressure plate 64 has a second friction material 67b attached to it. When the friction plate 63 rotates relative to the pressure plate 64, the friction plate 63 slides against the second friction material 67b. The second friction material 67b may also be attached to the friction plate 63.

[0066] <Biasing member> The biasing member 65 is positioned axially between the second side plate 62 and the pressure plate 64. The biasing member 65 biases the pressure plate 64 toward the first axial direction. That is, the biasing member 65 biases the pressure plate 64 toward the first side plate 61. As a result, the friction plate 63 is sandwiched between the pressure plate 64 and the first side plate 61. The biasing member 65 is an annular shape extending in the circumferential direction. The biasing member 65 is, for example, a disc spring. The biasing member 65 is in contact with the second inner circumference 621 at its outer circumference end and in contact with the pressure plate 64 at its inner circumference end.

[0067] [Damper Unit] As shown in Figure 1, the damper unit 7 is attached to the flexible plate 2. More specifically, the damper unit 7 is attached to the torque limiter 6. That is, the damper unit 7 is attached to the flexible plate 2 via the torque limiter 6 and the inertia block 5. The damper unit 7 is configured to dampen rotational fluctuations. The damper unit 7 has a first rotating member 71, a second rotating member 72, and a plurality of elastic members 73.

[0068] <First rotating member> The first rotating member 71 is configured to receive torque from the flexible plate 2. More specifically, the first rotating member 71 receives torque from the flexible plate 2 via a torque limiter 6. The first rotating member 71 rotates integrally with the friction plate 63 of the torque limiter 6. The first rotating member 71 has a first plate 71a and a second plate 71b. Both the first plate 71a and the second plate 71b are annular members having a central hole. The first plate 71a and the second plate 71b rotate integrally with each other. Furthermore, the first plate 71a and the second plate 71b are immovable relative to each other in the axial direction. The first plate 71a and the second plate 71b are fastened to each other by a plurality of fastening members 106.

[0069] The first plate 71a and the second plate 71b are arranged with a gap between them in the axial direction. The second plate 71b is positioned on the second axial side relative to the first plate 71a.

[0070] The first plate 71a and the second plate 71b each have multiple window portions 711a and 711b. In this embodiment, the first plate 71a and the second plate 71b each have four window portions 711a and 711b, but the number is not limited to this.

[0071] Each window section 711a, 711b is spaced apart from each other in the circumferential direction. Each window section 711a, 711b is configured to accommodate the elastic member 73.

[0072] The outer periphery of the first rotating member 71 overlaps with the friction surface between the friction plate 63 and the first side plate 61 in an axial view. The outer periphery of the first rotating member 71 is positioned on the first axial side relative to the torque limiter 6.

[0073] <Second rotating member> The second rotating member 72 is configured to transmit torque from the first rotating member 71 to the output member. The second rotating member 72 is positioned axially between the first plate 71a and the second plate 71b. The second rotating member 72 is positioned to be rotatable relative to the first plate 71a and the second plate 71b.

[0074] The second rotating member 72 has a hub 721 and a flange plate 722. The hub 721 and the flange plate 722 are configured as separate members, but they may also be formed integrally as a single member.

[0075] The hub 721 is cylindrical and extends axially. The hub 721 is positioned within the central holes of the first plate 71a and the second plate 71b. Spline holes extending axially are formed on the inner circumference of the hub 721. The input shaft of the output-side member can be spline-fitted into these spline holes.

[0076] The flange plate 722 extends radially from the outer circumferential surface of the hub 721. The flange plate 722 is formed in an annular shape. The flange plate 722 is rotatably positioned relative to the first plate 71a and the second plate 71b. In the axial direction, the flange plate 722 is positioned between the first plate 71a and the second plate 71b.

[0077] The flange plate 722 has a plurality of accommodating holes 723. In this embodiment, the flange plate 722 has four accommodating holes 723, but this number is not limited to this. Each accommodating hole 723 is spaced apart from each other in the circumferential direction. Each accommodating hole 723 is configured to accommodate an elastic member 73. Each accommodating hole 723 is positioned to overlap with each window portion 711a, 711b in an axial view.

[0078] <Elastic material> The elastic member 73 is configured to elastically connect the first rotating member 71 and the second rotating member 72 in the rotational direction. The elastic member 73 is, for example, a coil spring.

[0079] The elastic member 73 is housed in the housing hole 723 of the second rotating member 72. The elastic member 73 is also housed in the window portion 711a of the first plate 71a and in the window portion 711b of the second plate 71b. The elastic member 73 is positioned radially inward relative to the torque limiter 6.

[0080] As described above, in the above embodiment, a drive plate 3 having a plate thickness greater than that of the flexible plate 2 is attached to the flexible plate 2. This drive plate 3 can function as at least a part of the inertial ring used in conventional power transmission devices. Therefore, at least a part of the inertial ring can be omitted to reduce costs. For example, in this embodiment, costs can be reduced by using a plurality of inertial blocks 5 arranged at intervals in the circumferential direction instead of an inertial ring.

[0081] In the above embodiment, the inner circumference of the drive plate 3 is positioned radially inward relative to the protrusion 21 of the flexible plate 2, thereby improving the rigidity of the drive plate 3. Furthermore, the inner circumference of the drive plate 3 can regulate the amount of deflection of the disc spring 4.

[0082] [Differentiation] Although embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications are possible without departing from the spirit of the invention. Furthermore, the following modifications can basically be applied simultaneously.

[0083] (a) As shown in Figure 5, the outer peripheral end 41 of the disc spring 4 may be in contact with the convex portion 21, and the inner peripheral end 42 may be in contact with the drive plate 3. In this case, the stepped portion 33 of the drive plate 3 may be in contact with the inner peripheral surface of the disc spring 4.

[0084] (b) As shown in Figure 6, the power transmission device 100 does not have to have a disc spring 4. In this case, the protrusion 21 of the flexible plate 2 is in contact with the drive plate 3. More specifically, the protrusion 21 is in contact with the inner circumference of the first annular portion 31 of the drive plate 3. The inner circumference of the first annular portion 31 of the drive plate 3 is spaced apart from the flexible plate 2 in the axial direction, except for the protrusion 21.

[0085] Since the protrusion 21 is in contact with the drive plate 3 in this manner, if the flexible plate 2 is deflected in the axial direction during the operation of the power transmission device 100, the protrusion 21 slides against the drive plate 3, thereby suppressing resonance.

[0086] (c) In the above embodiment, the damper unit 7 was attached to the inertia block 5 via a torque limiter 6, but the configuration of the power transmission device 100 is not limited thereto. For example, the damper unit 7 may be attached directly to the inertia block 5 without a torque limiter 6. That is, the power transmission device 100 does not have a torque limiter 6. In this case, the first rotating member 71 of the damper unit 7 is attached to the inertia block 5.

[0087] (d) In the above embodiment, the power transmission device 100 had a plurality of inertia blocks 5, but the configuration of the power transmission device 100 is not limited thereto. For example, the power transmission device 100 may have an inertia ring instead of inertia blocks 5. The inertia ring is annular in shape and extends in the circumferential direction. In this case, since the power transmission device 100 has a drive plate 3, the thickness and diameter of the inertia ring can be reduced compared to a conventional inertia ring. As a result, the power transmission device 100 can be made less expensive.

[0088] Furthermore, the power transmission device 100 does not necessarily have an inertia block 5 or an inertia ring. In other words, the torque limiter 6 may be directly attached to the flexible plate 2 or the drive plate 3.

[0089] (e) In the above embodiment, the drive plate 3 was positioned on the first axial side relative to the flexible plate 2, but the drive plate 3 may be positioned on the second axial side relative to the flexible plate 2. In this case, the convex portion 21 of the flexible plate 2 protrudes on the second axial side. [Explanation of symbols]

[0090] 2: Flexible plate 21: Convex part 3: Drive Plate 31: First Ring Section 32: First cylindrical section 4: Disc spring 41: Outer edge 42: Inner edge 5: Inertia Block 6: Torque limiter 61: First side plate 611: Second Ring Section 612: Second cylindrical section 63: Friction Plate 64: Pressure plate 65: Biasing member 7: Damper Unit 71: First rotating member 72: Second rotating member 73: Elastic member 100: Power transmission device

Claims

1. A flexible plate configured to receive torque from the prime mover, A drive plate configured to rotate integrally with the flexible plate, Equipped with, The flexible plate has a protrusion that projects axially toward the drive plate, The drive plate is annular in shape, with its inner circumferential end positioned radially inward from the protrusion, and is thicker than the flexible plate. Power transmission device.

2. The system further comprises a disc spring positioned between the flexible plate and the drive plate in the axial direction, The disc spring contacts the protrusion and the drive plate. The power transmission device according to claim 1.

3. The disc spring abuts the drive plate at its outer circumference and abuts the protrusion at its inner circumference. The power transmission device according to claim 2.

4. The disc spring abuts against the protrusion at its outer circumference and abuts against the drive plate at its inner circumference. The power transmission device according to claim 2.

5. The drive plate abuts against the protrusion, The power transmission device according to claim 1.

6. The drive plate has an annular portion extending in the circumferential direction and a cylindrical portion extending axially from the outer peripheral end of the annular portion. The power transmission device according to claim 1.

7. The system further comprises an inertia member configured to rotate integrally with the flexible plate and the drive plate. The power transmission device according to claim 1.

8. The flexible plate further comprises a torque limiter attached to the aforementioned flexible plate. The power transmission device according to claim 1.

9. The torque limiter mentioned above is A first side plate attached to the flexible plate, A friction plate is arranged to be rotatable relative to the first side plate, A pressure plate that cooperates with the first side plate to clamp the friction plate, A biasing member that biases the pressure plate axially toward the first side plate, Having, The power transmission device according to claim 8.

10. The first side plate has an annular portion extending in the circumferential direction, and a cylindrical portion extending axially from the outer peripheral end of the annular portion toward the flexible plate. The power transmission device according to claim 9.

11. The cylindrical portion constitutes the outer surface of the power transmission device, The power transmission device according to claim 10.

12. The flexible plate is in contact with the inner circumferential surface of the cylindrical portion. The power transmission device according to claim 10.

13. The flexible plate is further equipped with a damper unit, The damper unit is, A first rotating member that receives torque from the flexible plate, A second rotating member is arranged to be rotatable relative to the first rotating member, An elastic member that elastically connects the first rotating member and the second rotating member, Having, The power transmission device according to claim 1.

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