Torque limiter and power transmission device

Abstract

To provide a torque limiter that can increase the outer diameter of the friction material. [Solution] The auxiliary plate is attached to the support plate. The auxiliary plate is positioned radially outward relative to the support plate. Multiple auxiliary plates are arranged in an annular shape. A first friction material is positioned axially between the support plate and the disc spring. The first friction material is adjacent to the support plate and each auxiliary plate. The support plate has multiple engagement slits extending radially inward from its outer circumferential surface. Each auxiliary plate has a plate body and an engagement piece. The plate body extends circumferentially. The engagement piece extends radially inward from the plate body. The engagement piece engages with the engagement slit. The engagement piece catches within the engagement slit to restrict the radially outward movement of the auxiliary plate.

Description

Technical Field

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

Background Art

[0002] In order to prevent the transmission of excessive torque, a power transmission device having a torque limiter has been proposed. For example, the power transmission device disclosed in Patent Document 1 includes a damper unit and a torque limiter. The torque limiter has a clutch composed of a plurality of plates, and the transmission of excessive torque is prevented by the slipping of this clutch. The torque limiter has a support plate for supporting a friction material and a disc spring for pressing the clutch.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the torque limiter configured as described above, there is a desire to increase the outer diameter of the friction material. Therefore, an object of the present invention is to provide a torque limiter capable of increasing the outer diameter of the friction material.

Means for Solving the Problems

[0005] A torque limiter according to the first embodiment comprises a first side plate, a support plate, a plurality of auxiliary plates, a disc spring, and a first friction material. The first side plate is annular. The support plate is annular. The support plate is spaced apart from the first side plate in the axial direction. The auxiliary plates are attached to the support plate. The auxiliary plates are positioned radially outward from the support plate. The plurality of auxiliary plates are arranged in an annular shape. The disc spring is positioned between the support plate and the first side plate in the axial direction. The first friction material is positioned between the support plate and the disc spring in the axial direction. The first friction material is adjacent to the support plate and each auxiliary plate. The support plate has a plurality of engagement slits extending radially inward from its outer circumferential surface. Each auxiliary plate has a plate body and an engagement piece. The plate body extends in the circumferential direction. The engagement piece extends radially inward from the plate body. The engagement piece engages with the engagement slit. The engaging piece is configured to catch within the engaging slit in order to restrict the radially outward movement of the auxiliary plate.

[0006] Conventionally, friction materials were supported by a support plate, making it impossible to make the outer diameter of the friction material larger than the outer diameter of the support plate. In contrast, in the torque limiter according to the first embodiment described above, an auxiliary plate is attached to the support plate, so the friction material can be supported by both the support plate and the auxiliary plate. Therefore, the outer diameter of the friction material can be made larger than the outer diameter of the support plate. As a result, even when there is a limit on the outer diameter of the support plate, the outer diameter of the friction material can be increased. Furthermore, since the auxiliary plate is configured to catch within the engagement slit of the support plate, it is possible to suppress the movement of the auxiliary plate radially outward due to centrifugal force.

[0007] The torque limiter according to the second embodiment is configured as follows in the torque limiter according to the first embodiment: The engaging piece has an extended portion and a hooking portion. The extended portion extends radially inward from the plate body. The hooking portion extends circumferentially from the extended portion.

[0008] The torque limiter according to the third embodiment is configured as follows in the torque limiter according to the second embodiment: The auxiliary plate has a pair of engaging pieces. The hooking portions of each engaging piece extend circumferentially toward each other.

[0009] The torque limiter according to the fourth embodiment is configured as follows in the torque limiter according to the third embodiment: The support plate has a pair of projections that protrude in the axial direction. A pair of engaging pieces are arranged between the pair of projections in the circumferential direction.

[0010] The torque limiter according to the fifth embodiment is configured as follows in the torque limiter according to any of the first to fourth embodiments: The first friction material has a groove. The groove is formed on the surface that contacts the support plate and the auxiliary plate. The groove opens radially outward. In an axial view, the groove overlaps with the boundary between the engagement slit and the engagement piece.

[0011] A torque limiter according to the sixth embodiment further comprises a second side plate, a pressure plate, and a second friction material in addition to the torque limiter according to any of the first to fifth embodiments. The second side plate is positioned such that a support plate, an auxiliary plate, a disc spring, and a first friction material are positioned between the second side plate and the first side plate. The second side plate is annular. The pressure plate is positioned in the axial direction between the disc spring and the first friction material. The second friction material is positioned in the axial direction between the support plate and the second side plate.

[0012] A torque limiter according to the seventh embodiment further comprises a second side plate, a pressure plate, and a second friction material in addition to the torque limiter according to any of the first to fifth embodiments. The second side plate is positioned between the second side plate and the first side plate such that a support plate, an auxiliary plate, a disc spring, and the first friction material are positioned between the second side plate and the first side plate. The second side plate is annular. The pressure plate is positioned axially between the disc spring and the first friction material. The second friction material is positioned axially between the support plate and the second side plate. The first friction material has a first through hole that penetrates axially. The second friction material has a second through hole that penetrates axially. The support plate has a first projection, a second projection, a first region, and a second region. The first projection protrudes toward the first friction material and engages with the first through hole. The second projection protrudes toward the second friction material and engages with the second through hole. The first region is defined by a pair of adjacent engagement slits in the circumferential direction and is the region where the first projection is formed. The second region is defined by a pair of adjacent engagement slits in the circumferential direction and is the region where the second projection is formed. The first region extends linearly when the folded portion toward the first friction material is sandwiched between the pressure plate and the second side plate. The second region extends linearly when the folded portion toward the second friction material is sandwiched between the pressure plate and the second side plate.

[0013] The torque limiter according to the eighth embodiment is configured as follows in the torque limiter according to any of the first to seventh embodiments: The inner circumferential edge of the disc spring is positioned radially outward relative to the outer circumferential edge of the support plate. The inner circumferential edge of the disc spring is also positioned radially inward relative to the outer circumferential edge of each auxiliary plate. With this configuration, the first friction material can be sandwiched between the disc spring and the auxiliary plate, so that even if the disc spring and the support plate are taken from a single plate, a uniform load can be applied to the first friction material.

[0014] The torque limiter according to the ninth aspect is configured as follows in the torque limiter according to any one of the first to eighth aspects. The disc spring has the same plate thickness as the support plate.

[0015] The power transmission device according to the tenth aspect includes the torque limiter according to any one of the first to ninth aspects and a damper unit. The damper unit has an input rotating body, an output rotating body, and an elastic member. The input rotating body is configured to rotate integrally with the support plate. The elastic member elastically connects the input rotating body and the output rotating body.

Advantages of the Invention

[0016] According to the present invention, the outer diameter of the friction material can be increased.

Brief Description of the Drawings

[0017] [Figure 1] Front view of the power transmission device. [Figure 2] Cross-sectional view taken along line II-II of FIG. 1. [Figure 3] Front view of the support plate. [Figure 4] Cross-sectional view of the torque limiter before assembly. [Figure 5] Cross-sectional view of the torque limiter after assembly. [Figure 6] Front view of the support plate with the auxiliary plate attached. [Figure 7] Front view of the auxiliary plate. [Figure 8] Front view of the first friction material. [Figure 9] View taken in the direction of arrow IX-IX of FIG. 8. [Figure 10] Enlarged front view of the support plate with the first friction material and the auxiliary plate attached. [Figure 11] Front view of the plate from which the support plate, the disc spring, and the plurality of auxiliary plates are removed. [Figure 12] Front view of the auxiliary plate according to the modification attached to the support plate. [Figure 13]Front view of the auxiliary plate according to a modified example attached to the support plate. [Figure 14] Front view of the auxiliary plate according to a modified example attached to the support plate.

Embodiments of the Invention

[0018] Hereinafter, the torque limiter 3 and the power transmission device 100 according to the present embodiment will be described with reference to the drawings. In the following description, the axial direction is the direction in which the rotation axis O of the torque limiter 3 and 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 left side in FIG. 2, and the second axial side means the right side in FIG. 2.

[0019] FIG. 1 is a front view of the power transmission device 100, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. As shown in FIGS. 1 and 2, the power transmission device 100 includes a torque limiter 3 and a damper unit 4. The torque limiter 3 and the damper unit 4 basically rotate 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, an electric motor, a generator, or a transmission. The power transmission device 100 is attached to a flywheel (not shown). For example, in FIG. 2, the internal combustion engine is disposed on the left side of the power transmission device 100, and the output side member is disposed 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.

[0020] [Damper Unit] The damper unit 4 is attached to the torque limiter 3. The damper unit 4 is configured to attenuate rotational fluctuations. The damper unit 4 includes an input rotating body 41, an output rotating body 42, and an elastic member 43.

[0021] [Input Rotating Body] The input rotating body 41 rotates integrally with the support plate 33 of the torque limiter 3, which will be described later. The input rotating body 41 has a first plate 41a and a second plate 41b. Both the first plate 41a and the second plate 41b are annular members having a central hole. The first plate 41a and the second plate 41b rotate integrally with each other. Furthermore, the first plate 41a and the second plate 41b are immovable relative to each other in the axial direction.

[0022] The first plate 41a and the second plate 41b are arranged with a gap between them in the axial direction. The second plate 41b is positioned second axially relative to the first plate 41a.

[0023] The first plate 41a and the second plate 41b each have multiple window portions 411a and 411b. In this embodiment, the first plate 41a and the second plate 41b each have four window portions 411a and 411b, but the number is not limited to this.

[0024] Each window section 411a, 411b is spaced apart from each other in the circumferential direction. Each window section 411a, 411b is configured to accommodate an elastic member 43.

[0025] <Output Rotating Body> The output rotating body 42 is configured to transmit torque from the input rotating body 41 to the output side member. The output rotating body 42 is positioned axially between the first plate 41a and the second plate 41b. The output rotating body 42 is positioned to be rotatable relative to the first plate 41a and the second plate 41b.

[0026] The output rotating body 42 has a hub 421 and a flange plate 422. The hub 421 and the flange plate 422 are integrally formed as a single component, but they may be constructed as separate components.

[0027] The hub 421 is cylindrical and is positioned within the central holes of the first plate 41a and the second plate 41b. A splined hole extending in the axial direction is formed on the inner circumference of the hub 421. The input shaft of the output-side member can be spline-fitted into this splined hole.

[0028] The flange plate 422 extends radially from the outer circumferential surface of the hub 421. The flange plate 422 is formed in an annular shape. The flange plate 422 is rotatably positioned relative to the first plate 41a and the second plate 41b. In the axial direction, the flange plate 422 is positioned between the first plate 41a and the second plate 41b.

[0029] The flange plate 422 has a plurality of accommodating holes 423. In this embodiment, the flange plate 422 has four accommodating holes 423, but this number is not limited to this. Each accommodating hole 423 is spaced apart from each other in the circumferential direction. Each accommodating hole 423 is configured to accommodate an elastic member 43. Each accommodating hole 423 is positioned to overlap with each window portion 411a, 411b in an axial view.

[0030] <Elastic material> The elastic member 43 is configured to elastically connect the input rotating body 41 and the output rotating body 42 in the rotational direction. The elastic member 43 is, for example, a coil spring.

[0031] The elastic member 43 is housed in the housing hole 423 of the output rotating body 42. The elastic member 43 is also housed in the window portion 411a of the first plate 41a and in the window portion 411b of the second plate 41b.

[0032] [torque limiter] The torque limiter 3 is rotatably positioned around the rotation axis O. The torque limiter 3 is located on the second axial side relative to the flywheel. The torque limiter 3 is annular in shape. The torque limiter 3 is mounted on the flywheel.

[0033] The torque limiter 3 is configured to limit the torque transmitted between the flywheel and the damper unit 4. In other words, the torque limiter 3 is configured to restrict the transmission of torque exceeding a predetermined value in the power transmission device 100.

[0034] The torque limiter 3 includes a first side plate 31, a second side plate 32, a support plate 33, a plurality of auxiliary plates 34, a first friction material 35a, a second friction material 35b, a pressure plate 36, and a disc spring 37.

[0035] <First side plate and second side plate> The first side plate 31 and the second side plate 32 are attached to the flywheel. The first side plate 31 and the second side plate 32 rotate integrally with the flywheel. The first side plate 31 and the second side plate 32 are annular in shape. The second side plate 32 is positioned axially apart from the first side plate 31. The second side plate 32 is positioned axially second to the first side plate 31. Between the first side plate 31 and the second side plate 32 are a support plate 33, each auxiliary plate 34, a first friction material 35a, a second friction material 35b, a pressure plate 36, and a disc spring 37. The thickness of the second side plate 32 is greater than the thickness of the first side plate 31.

[0036] <Support plate> The support plate 33 is an annular plate. The support plate 33 is rotatably positioned around the rotation axis O. The support plate 33 is positioned at a distance from the first side plate 31 in the axial direction.

[0037] The support plate 33 is attached to the input rotating body 41. More specifically, the support plate 33 is attached to the first plate 41a. For example, the support plate 33 is attached to the first plate 41a by a fastening member 101. The support plate 33 rotates integrally with the input rotating body 41. Although the support plate 33 is a separate component from the first plate 41a, the support plate 33 may be integrally constructed with the first plate 41a as a single component.

[0038] Figure 3 is a front view of the support plate 33. In Figure 3, the second friction material 35b is also shown by a dashed line. As shown in Figure 3, the support plate 33 has a plurality of engagement slits 335. Each engagement slit 335 extends radially inward from the outer circumferential surface of the support plate 33. More specifically, the engagement slits 335 extend radially inward from the outer circumferential surface of the support plate 33, with their tips extending circumferentially. The tips of adjacent pairs of engagement slits 335 extend toward each other. The support plate 33 has multiple such pairs of engagement slits 335.

[0039] The radially inner end of each engagement slit 335 is positioned radially inward relative to the inner periphery of the first friction material 35a and the second friction material 35b. That is, a portion of each engagement slit 335 is exposed from the first friction material 35a and the second friction material 35b in an axial view.

[0040] Each engagement slit 335 opens radially outward. The engagement slits 335 are formed on the outer circumference of the support plate 33. The engagement slits 335 penetrate the support plate 33 in the axial direction. Each engagement slit 335 is spaced apart from one another in the circumferential direction.

[0041] As shown in Figures 2 and 3, the support plate 33 has a plurality of first protrusions 331 and a plurality of second protrusions 332. The first protrusions 331 and the second protrusions 332 are arranged alternately in the circumferential direction. The first protrusions 331 and the second protrusions 332 are arranged on the same circumference. In the following description, the first protrusions 331 and the second protrusions 332 are collectively referred to as protrusions 331 and 332. The protrusions 331 and 332 protrude in the axial direction.

[0042] The first projection 331 protrudes toward the first friction material 35a. That is, the first projection 331 protrudes toward the first axial direction. The first projection 331 engages with the first through hole 351a of the first friction material 35a, which will be described later.

[0043] The second projection 332 protrudes toward the second friction material 35b. That is, the second projection 332 protrudes toward the second axial direction. The second projection 332 engages with the second through hole 351b of the second friction material 35b, which will be described later.

[0044] As shown in Figure 3, the support plate 33 has a plurality of first regions 333, a plurality of second regions 334, and a plurality of third regions 336. The first region 333 is defined by a pair of adjacent engagement slits 335 in the circumferential direction. A first projection 331 is formed in the first region 333. That is, the region between a pair of adjacent engagement slits 335 in the circumferential direction where the first projection 331 is formed is the first region 333.

[0045] Figure 4 is a cross-sectional view of the torque limiter 3 before assembly, and Figure 5 is a cross-sectional view of the torque limiter 3 after assembly. As shown in Figure 4, in the state before the torque limiter 3 is assembled, that is, before an axial load is applied to the support plate 33, the first region 333 is bent toward the first friction material 35a. That is, the first region 333 is bent toward the first axial direction. This makes it easier to fit the first projection 331 of the support plate 33 into the first through hole 351a of the first friction material 35a.

[0046] As shown in Figure 5, when the torque limiter 3 is assembled, that is, when the first side plate 31 is fastened to the second side plate 32 with multiple rivets 102, the support plate 33 including the first region 333 is sandwiched between the second side plate 32 and the pressure plate 36. As a result, an axial load is applied to the support plate 33 including the first region 333, and the first region 333, which was bent in the axial direction, extends linearly in the radial direction.

[0047] As shown in Figure 3, the second region 334 is defined by a pair of adjacent engagement slits 335 in the circumferential direction. A second projection 332 is formed in the second region 334. That is, the region between the pair of adjacent engagement slits 335 in the circumferential direction, where the second projection 332 is formed, is the second region 334.

[0048] The first region 333 and the second region 334 are arranged alternately in the circumferential direction. A third region 336 is interposed between the first region 333 and the second region 334. In the region between the pair of engagement slits 335, only the first protrusion 331 is formed, only the second protrusion 332 is formed, or neither protrusions 331 nor 332 are formed. Both the first protrusion 331 and the second protrusion 332 are not formed in a single region.

[0049] As shown in Figure 4, in the state before the torque limiter 3 is assembled, that is, before an axial load is applied to the support plate 33, the second region 334 is bent toward the second friction material 35b. In other words, the second region 334 is bent toward the second axial direction. This makes it easier to fit the second projection 332 of the support plate 33 into the second through hole 351b of the second friction material 35b.

[0050] As shown in Figure 5, when the torque limiter 3 is assembled, that is, when the first side plate 31 is fastened to the second side plate 32 with multiple rivets 102, the support plate 33 including the second region 334 is sandwiched between the second side plate 32 and the pressure plate 36. As a result, an axial load is applied to the support plate 33 including the second region 334, and the second region 334, which was bent in the axial direction, extends linearly in the radial direction.

[0051] As shown in Figure 3, the third region 336 is positioned between the first region 333 and the second region 334 in the circumferential direction. No protrusions 331 and 332 are formed in the third region 336. The tip of each engagement slit 335 extends circumferentially toward the third region 336.

[0052] <Support plate> Figure 6 is a front view showing each auxiliary plate 34 attached to the support plate 33. As shown in Figure 6, each auxiliary plate 34 is positioned radially outward relative to the support plate 33. Each auxiliary plate 34 is attached to the support plate 33. Each auxiliary plate 34 rotates integrally with the support plate 33.

[0053] In this embodiment, the torque limiter 3 has six auxiliary plates 34. Each auxiliary plate 34 is arranged in an annular shape; that is, each auxiliary plate 34 is arranged in the circumferential direction. Each auxiliary plate 34 is spaced apart from each other in the circumferential direction. However, each auxiliary plate 34 may be in contact with each other.

[0054] Figure 7 is a front view of the auxiliary plate 34. As shown in Figure 7, the auxiliary plate 34 has a plate body portion 342 and a plurality of engaging pieces 343. In this embodiment, the auxiliary plate 34 has four engaging pieces 343. The plate body portion 342 extends in the circumferential direction. The plate body portion 342 is arc-shaped with respect to the rotation axis O.

[0055] The engaging pieces 343 extend radially inward from the plate body 342. Each engaging piece 343 is spaced apart from the others in the circumferential direction. The engaging pieces 343 engage with the engaging slits 335. The engaging pieces 343 and the engaging slits 335 extend in the same direction. The shape of the engaging pieces 343 is substantially the same as the shape of the engaging slits 335. By engaging the engaging pieces 343 with the engaging slits 335, the auxiliary plate 34 is attached to the support plate 33.

[0056] The engaging piece 343 is configured to catch within the engaging slit 335. Therefore, even when the power transmission device 100 rotates and centrifugal force acts on the auxiliary plate 34, the engaging piece 343 catches on the inner wall surface of the engaging slit 335, restricting the auxiliary plate 34 from moving radially outward and preventing the auxiliary plate 34 from detaching from the support plate 33.

[0057] In detail, the auxiliary plate 34 has at least one pair of engaging pieces 343. In this embodiment, however, the auxiliary plate 34 has four engaging pieces 343. That is, the auxiliary plate 34 has two pairs of engaging pieces 343.

[0058] Each engaging piece 343 has an extended portion 344 and a hooking portion 345. The extended portion 344 extends radially inward from the plate body portion 342. In other words, the extended portion 344 is the radially extending part of the engaging piece 343. The extended portion 344 extends toward the axis of rotation O.

[0059] The hook portion 345 extends circumferentially from the extended portion 344. That is, the hook portion 345 is the part of the engaging piece 343 that extends circumferentially. The hook portion 345 extends circumferentially from the tip of the extended portion 344. In a pair of adjacent engaging pieces 343 in the circumferential direction, each hook portion 345 extends circumferentially toward each other. Note that adjacent pairs of hook portions 345 are spaced apart from each other in the circumferential direction.

[0060] The pair of engaging pieces 343 are positioned so as to sandwich the center of gravity G of the auxiliary plate 34 in the circumferential direction together with another pair of engaging pieces 343. This makes it possible to more reliably prevent the auxiliary plate 34 from moving radially outward and detaching from the support plate 33.

[0061] As shown in Figure 6, the pair of engaging pieces 343 are positioned between the pair of protrusions 331 and 332 in the circumferential direction. More specifically, the pair of engaging pieces 343, formed so that the hook portions 345 face each other, are positioned between the first protrusion 331 and the second protrusion 332 in the circumferential direction. Note that the protrusions 331 and 332 are not positioned between the pair of engaging pieces 343, formed so that the hook portions 345 face each other.

[0062] <Friction material> As shown in Figure 2, the first friction material 35a is positioned in the axial direction between the support plate 33 and the disc spring 37. More specifically, the first friction material 35a is positioned in the axial direction between the support plate 33 and the pressure plate 36. The first friction material 35a is adjacent to the support plate 33 and the auxiliary plate 34 in the axial direction.

[0063] The first friction material 35a has a first through hole 351a. The first through hole 351a penetrates the first friction material 35a in the axial direction. The first friction material 35a is attached to the support plate 33. More specifically, the first friction material 35a is attached to the support plate 33 by a first projection 331 of the support plate 33 engaging with the first through hole 351a of the first friction material 35a. The first friction material 35a rotates integrally with the support plate 33.

[0064] The first friction material 35a is annular in shape. The first friction material 35a extends across the support plate 33 and the auxiliary plate 34. That is, in an axial view, the first friction material 35a overlaps with both the support plate 33 and the auxiliary plate 34. The inner diameter of the first friction material 35a is smaller than the outer diameter of the support plate 33. The outer diameter of the first friction material 35a is larger than the outer diameter of the support plate 33. Also, the outer diameter of the first friction material 35a is less than or equal to the outer diameter of the auxiliary plate 34. In this embodiment, the outer diameter of the first friction material 35a is substantially the same as the outer diameter of the auxiliary plate 34. Furthermore, the outer diameter of the auxiliary plate 34 refers to the length from the axis of rotation O to the outer edge of the auxiliary plate 34.

[0065] Figure 8 is a front view of the first friction material 35a as seen from the second axial side, and Figure 9 is a view taken along the line IX-IX in Figure 8. As shown in Figures 8 and 9, the first friction material 35a has a plurality of grooves 352a. Each groove 352a is spaced apart from each other in the circumferential direction. Each groove 352a is spaced at the same pitch as each engaging piece 343. The width of the grooves 352a is greater than the width of the engaging piece 343. More specifically, the width of the grooves 352a is greater than the width of the extended portion 344 of the engaging piece 343. Here, the width of the grooves 352a and the width of the engaging piece 343 refer to the circumferential dimensions. Each groove 352a extends radially. Each groove 352a opens radially outward.

[0066] Each groove 352a is formed on the surface of the first friction material 35a that is in contact with the support plate 33 and the auxiliary plate 34. That is, each groove 352a is formed on the surface of the first friction material 35a that faces the second side in the axial direction. Each groove 352a does not penetrate the first friction material 35a in the axial direction.

[0067] Figure 10 is an enlarged front view of the support plate 33 to which the auxiliary plate 34 and the first friction material 35a are attached. As shown in Figure 10, the groove 352a overlaps with the boundary between the engagement slit 335 and the engagement piece 343 in an axial view. This allows water that accumulates in the gap between the engagement slit 335 and the engagement piece 343 to be discharged to the outside through the groove 352a. Preferably, the groove 352a overlaps with the base of the engagement piece 343 in an axial view.

[0068] As shown in Figure 2, the second friction material 35b is positioned in the axial direction between the support plate 33 and the second side plate 32. The second friction material 35b is adjacent to the support plate 33 and the auxiliary plate 34 in the axial direction. The second friction material 35b has the same configuration as the first friction material 35a. That is, the second friction material 35b has a plurality of second through holes 351b and a plurality of grooves (not shown). Note that the second friction material 35b does not necessarily have grooves.

[0069] The second through-hole 351b penetrates the second friction material 35b axially. The second friction material 35b is attached to the support plate 33. More specifically, the second friction material 35b is attached to the support plate 33 by a second projection 332 of the support plate 33 engaging with the second through-hole 351b of the second friction material 35b. The second friction material 35b rotates integrally with the support plate 33.

[0070] The second friction material 35b is annular in shape. The second friction material 35b extends across the support plate 33 and the auxiliary plate 34. That is, in an axial view, the second friction material 35b overlaps with both the support plate 33 and the auxiliary plate 34. The inner diameter of the second friction material 35b is smaller than the outer diameter of the support plate 33. The outer diameter of the second friction material 35b is larger than the outer diameter of the support plate 33. Furthermore, the outer diameter of the second friction material 35b is less than or equal to the outer diameter of the auxiliary plate 34. In this embodiment, the outer diameter of the second friction material 35b is substantially the same as the outer diameter of the auxiliary plate 34.

[0071] <Pressure Plate> The pressure plate 36 is annular in shape. In the axial direction, the pressure plate 36 is positioned between the disc spring 37 and the support plate 33. More specifically, in the axial direction, the pressure plate 36 is positioned between the first friction material 35a and the disc spring 37. The inner diameter of the pressure plate 36 is smaller than the inner diameter of the first friction material 35a. Also, the outer diameter of the pressure plate 36 is larger than the outer diameter of the first friction material 35a. That is, the pressure plate 36 can press against the entire surface of the first friction material 35a.

[0072] The pressure plate 36 is configured to rotate integrally with the second side plate 32. The pressure plate 36 is also movable axially relative to the second side plate 32.

[0073] <Disc spring> The disc spring 37 is positioned axially between the support plate 33 and the first side plate 31. More specifically, the disc spring 37 is positioned axially between the first side plate 31 and the pressure plate 36. The disc spring 37 biases the pressure plate 36 toward the second axial direction. That is, the disc spring 37 biases the pressure plate 36 toward the support plate 33. As a result, the support plate 33, the first friction material 35a, and the second friction material 35b are sandwiched between the pressure plate 36 and the second side plate 32.

[0074] The disc spring 37 is annular in shape. As shown in Figure 11, the disc spring 37 is made from a single plate together with the support plate 33. Therefore, the inner diameter of the disc spring 37 is greater than or equal to the outer diameter of the support plate 33. Also, the plate thickness of the disc spring 37 is the same as the plate thickness of the support plate 33.

[0075] In addition to the disc spring 37 and support plate 33, multiple auxiliary plates 34 are also taken from a single plate. The multiple auxiliary plates 34 are taken from the area surrounded by the support plate 33. For this reason, the thickness of each auxiliary plate 34 is the same as the thickness of the support plate 33. Figure 11 is a plan view showing a single plate from which the support plate 33, disc spring 37, and multiple auxiliary plates 34 are taken.

[0076] As shown in Figure 2, the disc spring 37 abuts the first side plate 31 at its outer peripheral end and the pressure plate 36 at its inner peripheral end. The inner edge of the disc spring 37 is positioned radially outward relative to the outer peripheral edge of the support plate 33. Furthermore, the inner edge of the disc spring 37 is positioned radially inward relative to the outer peripheral edge of the auxiliary plate 34. In other words, the disc spring 37 overlaps with the auxiliary plate 34 in an axial view. Therefore, a uniform load can be applied to the first friction material 35a.

[0077] [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.

[0078] (a) In the above embodiment, the engaging piece 343 has an extended portion 344 and a hooking portion 345, but the configuration of the engaging piece 343 is not limited thereto. For example, as shown in Figure 12, the engaging piece 343 may have an extended portion 344, a first hooking portion 345 and a second hooking portion 346. The first hooking portion 345 and the second hooking portion 346 extend circumferentially from the extended portion 344. The first hooking portion 345 and the second hooking portion 346 extend in opposite directions from each other.

[0079] (b) The engaging piece 343 may have a shape that gradually widens toward the radially inward direction. For example, the engaging piece 343 may be teardrop-shaped as shown in Figure 13, or triangular as shown in Figure 14. The width of the engaging piece 343 refers to its circumferential dimension.

[0080] (c) In the above embodiment, the first friction material 35a has grooves 352a, but the first friction material 35a does not have grooves 352a.

[0081] (d) The first friction material 35a and the second friction material 35b may be attached to the auxiliary plate 34 instead of the support plate 33. Alternatively, the first friction material 35a and the second friction material 35b may be attached to the support plate 33 or the auxiliary plate 34 by other means such as an adhesive. [Explanation of Symbols]

[0082] 3: Torque limiter 31: First side plate 32: Second side plate 33: Support plate 331: 1st protrusion 332:Second protrusion 333: 1st area 334:Second area 335: Engagement slit 34: Auxiliary plate 342: Plate body 343: Engaging piece 344 :Extension part 345: Hook part 35a: 1st friction material 351a: 1st through hole 351b: 2nd through hole 352a:Groove 35b: 2nd friction material 36: Pressure Plate 37: Disc spring 4: Damper Unit 41: Input Rotation Body 42: Output Rotating Body 43: Elastic member 100: Power transmission device

Claims

1. The annular first side plate, In the axial direction, an annular support plate is positioned at a distance from the first side plate, A plurality of auxiliary plates are attached to the support plate, positioned radially outward from the support plate, and arranged in an annular shape, A disc spring is positioned between the support plate and the first side plate in the axial direction, Displaced in the axial direction between the support plate and the disc spring, and adjacent to the support plate and each of the auxiliary plates, Equipped with, The support plate has a plurality of engagement slits extending radially inward from its outer surface, Each of the auxiliary plates has a plate body portion extending in the circumferential direction and an engaging piece extending radially inward from the plate body portion and engaging with the engaging slit. The engaging piece is configured to catch within the engaging slit so as to restrict the radially outward movement of the auxiliary plate. Torque limiter.

2. The engaging piece has an extended portion that extends radially inward from the plate body and a hooking portion that extends circumferentially from the extended portion. The torque limiter according to claim 1.

3. The auxiliary plate has a pair of the engagement pieces, The hooking portions of each of the aforementioned engaging pieces extend circumferentially toward each other. The torque limiter according to claim 2.

4. The support plate has a pair of protrusions that project in the axial direction, The pair of engaging pieces are positioned between the pair of protrusions in the circumferential direction. The torque limiter according to claim 3.

5. The first friction material has grooves that open radially outward on the surfaces that contact the support plate and each of the auxiliary plates, The groove portion overlaps with the boundary between the engagement slit and the engagement piece in an axial view. The torque limiter according to claim 1.

6. An annular second side plate is arranged between the first side plate such that the support plate, each of the auxiliary plates, the disc spring, and the first friction material are positioned therein. A pressure plate positioned between the disc spring and the first friction material in the axial direction, A second friction material is disposed between the support plate and the second side plate in the axial direction, Furthermore, The torque limiter according to claim 1.

7. An annular second side plate is arranged between the first side plate such that the support plate, each of the auxiliary plates, the disc spring, and the first friction material are positioned therein. A pressure plate positioned between the disc spring and the first friction material in the axial direction, A second friction material is disposed between the support plate and the second side plate in the axial direction, Furthermore, The first friction material has a first through hole that penetrates in the axial direction, The second friction material has a second through hole that penetrates in the axial direction, The support plate has a first projection that protrudes toward the first friction material and engages with the first through hole, a second projection that protrudes toward the second friction material and engages with the second through hole, a first region defined by a pair of adjacent engagement slits in the circumferential direction where the first projection is formed, and a second region defined by a pair of adjacent engagement slits in the circumferential direction where the second projection is formed. The first region extends linearly when it is bent toward the first friction material and sandwiched between the pressure plate and the second side plate. The second region extends linearly when the part that has been bent toward the second friction material is sandwiched between the pressure plate and the second side plate. The torque limiter according to claim 1.

8. The inner periphery of the disc spring is positioned radially outward relative to the outer periphery of the support plate, and radially inward relative to the outer periphery of each auxiliary plate. The torque limiter according to claim 1.

9. The disc spring has the same plate thickness as the support plate. The torque limiter according to claim 1.

10. A torque limiter according to any one of claims 1 to 9, A damper unit having an input rotating body, an output rotating body, and an elastic member that elastically connects the input rotating body and the output rotating body, configured to rotate integrally with the support plate, A power transmission device equipped with the following features.

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