Power transmission device and method of manufacturing the same

Abstract

To provide a power transmission device capable of reducing the cost.SOLUTION: A torque limiter unit includes a flywheel, a friction plate, a pressure plate, and an energizing member. The flywheel has a base portion and a support portion. The base portion includes a through hole penetrating in an axial direction. The support portion is disposed on a first side in the axial direction with a gap from the base portion. A damper unit is attached to the torque limiter unit. The damper unit includes an input rotating body, an output rotating body, and an elastic member. A first fastening member fastens the friction plate and the input rotating body. The first fastening member is disposed to be exposed in the axial direction via the through hole.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power transmission device and a method for manufacturing the same. [Background technology]

[0002] The power transmission device is configured to absorb torque fluctuations of the engine. This power transmission device has a flywheel, a torque limiter unit, and a damper unit (see, for example, Patent Document 1). The damper unit is attached to the flywheel via the torque limiter unit. The torque limiter unit is configured to restrict transmission of torque above a predetermined value between the flywheel and the damper unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-55810 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a cost reduction in the power transmission device configured as described above. Therefore, an object of the present invention is to provide a power transmission device that can be manufactured at a low cost. [Means for solving the problem]

[0005] A power transmission device according to a first aspect includes a torque limiter unit, a damper unit, and a first fastening member. The torque limiter unit has a flywheel, a friction plate, a pressure plate, and an urging member. The flywheel has a base portion and a support portion. The base portion includes a through hole that penetrates in the axial direction. The support portion is disposed on a first axial side at a distance from the base portion. The friction plate is disposed between the base portion and the support portion. The pressure plate presses the friction plate. The urging member urges the pressure plate toward the friction plate. The damper unit has an input rotor, an output rotor, and an elastic member. The input rotor is configured to rotate integrally with the friction plate. The output rotor is disposed to be rotatable relative to the input rotor. The elastic member elastically connects the input rotor and the output rotor. The first fastening member fastens the friction plate to the input rotor. The first fastening member is disposed so as to be exposed in the axial direction through the through hole.

[0006] According to this configuration, by using a flywheel as a component constituting the torque limiter unit, the number of components can be reduced, and costs can be lowered. Furthermore, because a through-hole is formed in the flywheel to expose the first fastening member, the torque limiter unit including the flywheel and the damper unit can be assembled separately, and then the torque limiter unit and the damper unit can be fastened together with the first fastening member.

[0007] The power transmission device according to the second aspect is the power transmission device according to the first aspect and is configured as follows: The input rotor has a pair of input plates and a second fastening member. The second fastening member fastens the pair of input plates at the outer peripheries of the pair of input plates. The second fastening member is arranged on a first axial side relative to the support portion. The second fastening member overlaps with the support portion when viewed in the axial direction.

[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 base portion has an engagement hole, and the pressure plate has an engagement claw that engages with the engagement 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 pressure plate has an annular main body portion, and the engagement claw extends from an inner peripheral end of the main body portion toward a second side in the axial direction.

[0010] A power transmission device according to a fifth aspect is the power transmission device according to the fourth aspect, and is configured as follows: The biasing member is a disc spring, and has an inner peripheral end that contacts the pressure plate and an outer peripheral end that contacts the base portion.

[0011] A power transmission device according to a sixth aspect is the power transmission device according to any one of the first to fifth aspects, and is configured as follows: The friction plate is sandwiched between the support portion and the pressure plate.

[0012] A seventh aspect of the present invention relates to the power transmission device of any one of the first to sixth aspects, and is configured as follows: the support portion has a threaded hole penetrating in the axial direction, and the biasing member is exposed in the axial direction through the threaded hole.

[0013] A method for manufacturing a power transmission device according to an eighth aspect is a method for manufacturing the power transmission device according to any one of the first to seventh aspects. This manufacturing method includes the steps of assembling a torque limiter unit, assembling a damper unit, and fastening a friction plate and an input rotating body via a through hole. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a power transmission device that can be manufactured at low cost. [Brief explanation of the drawings]

[0015] [Figure 1]FIG. [Figure 2] Cross-sectional view of line II-II in Figure 1. [Figure 3] FIG. 3 is a cross-sectional view of the power transmission device before assembly. [Figure 4] FIG. 10 is a cross-sectional view of the power transmission device in a state where the biasing force of the disc spring is disabled. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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. The first axial side refers to the right side in FIG. 2, and the second axial side refers to the left side in FIG. 2.

[0017] 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 in FIG. 1. As shown in FIGS. 1 and 2, the power transmission device 100 includes a torque limiter unit 3, a damper unit 4, and a first fastening member 5. The torque limiter unit 3 and the damper unit 4 basically rotate integrally with each other. The power transmission device 100 is disposed between an internal combustion engine (not shown) and an output member (not shown). The output member may be, for example, an electric motor or a transmission. The power transmission device 100 is attached to a crankshaft (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 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 member and to attenuate torque fluctuations.

[0018] [Damper unit] The damper unit 4 is attached to the torque limiter unit 3 by a first fastening member 5. The damper unit 4 is configured to damp rotation fluctuations. The damper unit 4 has an input rotor 41, an output rotor 42, and a plurality of elastic members 43.

[0019] <Input rotor> The input rotor 41 rotates integrally with a friction plate 32 of the torque limiter unit 3, which will be described later. The input rotor 41 has a pair of input plates 41a, 41b. More specifically, the input rotor 41 has a first input plate 41a and a second input plate 41b. The first input plate 41a and the second input plate 41b are both annular members having a center hole. The first input plate 41a and the second input plate 41b rotate integrally with each other. Furthermore, the first input plate 41a and the second input plate 41b are immovable relative to each other in the axial direction.

[0020] The first input plate 41a and the second input plate 41b are spaced apart from each other in the axial direction. The first input plate 41a is located on a first axial side relative to the second input plate 41b.

[0021] The first input plate 41a and the second input plate 41b each have a plurality of window portions 411a, 411b. In this embodiment, the first input plate 41a and the second input plate 41b each have four window portions 411a, 411b, but the number of window portions is not limited to four.

[0022] The windows 411a and 411b are spaced apart from each other in the circumferential direction. Each of the windows 411a and 411b is configured to accommodate an elastic member 43 therein.

[0023] The input rotor 41 further has a plurality of second fastening members 41c. The second fastening members 41c fasten the first input plate 41a and the second input plate 41b together at the outer peripheries of the first input plate 41a and the second input plate 41b.

[0024] The second fastening member 41c is disposed on a first axial side of a support portion 312, which will be described later. The second fastening member 41c overlaps with the support portion 312 when viewed in the axial direction. The second fastening member 41c is, for example, a rivet.

[0025] <Output rotor> The output rotor 42 is configured to transmit torque from the input rotor 41 to an output side member. The output rotor 42 is disposed axially between the first input plate 41a and the second input plate 41b. The output rotor 42 is disposed so as to be rotatable relative to the first input plate 41a and the second input plate 41b.

[0026] The output rotor 42 has a hub 421 and a flange plate 422. The hub 421 and the flange plate 422 are configured as separate members, but may be integrally formed as a single member. The hub 421 and the flange plate 422 rotate integrally.

[0027] The hub 421 is cylindrical and is disposed within the central holes of the first input plate 41a and the second input plate 41b. A spline hole extending in the axial direction is formed in the inner periphery of the hub 421. The input shaft of the output side member can be spline-fitted into this spline 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 arranged to be rotatable relative to the first input plate 41a and the second input plate 41b. The flange plate 422 is arranged between the first input plate 41a and the second input plate 41b in the axial direction.

[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. The accommodating holes 423 are arranged at intervals from one another in the circumferential direction. Each accommodating hole 423 is configured to accommodate an elastic member 43. Each accommodating hole 423 is arranged at a position overlapping with each window portion 411a, 411b when viewed in the axial direction.

[0030] <Elastic material> The elastic member 43 is configured to elastically connect the input rotor 41 and the output rotor 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 rotor 42. The elastic member 43 is housed in the window 411a of the first input plate 41a and also in the window 411b of the second input plate 41b.

[0032] [Torque limiter] As shown in FIG. 2, the torque limiter unit 3 is disposed rotatably about a rotation axis O. The torque limiter unit 3 is disposed on a second axial side relative to the damper unit 4. The torque limiter unit 3 is annular. The torque limiter unit 3 is attached to the crankshaft by a plurality of bolts 101. Each bolt 101 is exposed on a first axial side. That is, each member constituting the damper unit 4 has a through hole or a notch or the like so as not to overlap with each bolt 101 when viewed in the axial direction.

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

[0034] The torque limiter unit 3 includes a flywheel 31, a friction plate 32, a first friction material 33a, a second friction material 33b, a pressure plate 34, and a disc spring 35 (an example of a biasing member).

[0035] <Flywheel> The flywheel 31 is attached to the crankshaft by a plurality of bolts 101. The flywheel 31 rotates integrally with the crankshaft.

[0036] The flywheel 31 has a base portion 311 and a support portion 312. The support portion 312 is attached to the base portion 311 by a plurality of bolts 102. The support portion 312 rotates integrally with the base portion 311.

[0037] The base portion 311 is a disc-shaped plate with an opening in the center. The base portion 311 has a plurality of through holes 311a and a plurality of engagement holes 311b. The through holes 311a are arranged at intervals in the circumferential direction. The through holes 311a penetrate the base portion 311 in the axial direction.

[0038] The engagement holes 311b are arranged at intervals in the circumferential direction and penetrate the base portion 311 in the axial direction.

[0039] The support portion 312 is annular and extends in the circumferential direction. The support portion 312 is disposed on a first axial side relative to the base portion 311. The support portion 312 is disposed at a distance in the axial direction relative to the base portion 311. Specifically, the inner periphery of the support portion 312 is disposed at a distance in the axial direction relative to the base portion 311. The outer periphery of the support portion 312 is in contact with the base portion 311. The outer periphery of the support portion 312 is attached to the base portion 311.

[0040] The support portion 312 has a screw hole 312a. The screw hole 312a penetrates the inner periphery of the support portion 312 in the axial direction. The screw hole 312a opens into the space between the inner periphery of the support portion 312 and the base portion 311. A disc spring 35, which will be described later, is exposed to the first axial side through the screw hole 312a. In other words, the screw hole 312a faces the disc spring 35 in the axial direction.

[0041] The friction plate 32, the first friction material 33a, the second friction material 33b, the pressure plate 34, and the disc spring 35 are arranged between the base portion 311 and the support portion 312. The plate thickness of the support portion 312 is thicker than the plate thickness of the base portion 311.

[0042] <Friction plate> The friction plate 32 is an annular plate. The friction plate 32 is disposed rotatably about a rotation axis O. The friction plate 32 is disposed between a base portion 311 and a support portion 312 in the axial direction. More specifically, the friction plate 32 is sandwiched between a pressure plate 34 and the support portion 312. The friction plate 32 is frictionally engaged with the support portion 312 via a first friction material 33a. The friction plate 32 is also frictionally engaged with the pressure plate 34 via a second friction material 33b.

[0043] The friction plate 32 is attached to the input rotor 41. More specifically, the friction plate 32 is attached to the second input plate 41b. The friction plate 32 is attached to the second input plate 41b by the first fastening member 5. The friction plate 32 rotates integrally with the input rotor 41.

[0044] <Friction material> The first friction material 33a has an annular shape extending in the circumferential direction. The first friction material 33a is disposed on a first axial side of the friction plate 32. That is, the first friction material 33a is disposed between the friction plate 32 and the support portion 312 in the axial direction. The first friction material 33a is attached to the friction plate 32. The first friction material 33a rotates integrally with the friction plate 32.

[0045] The second friction material 33b has an annular shape extending in the circumferential direction. The second friction material 33b is disposed on a second axial side with respect to the friction plate 32. That is, the second friction material 33b is disposed between the friction plate 32 and the base portion 311 in the axial direction. More specifically, the second friction material 33b is disposed between the friction plate 32 and the pressure plate 34. The second friction material 33b is attached to the friction plate 32. The second friction material 33b rotates integrally with the friction plate 32.

[0046] <Pressure plate> The pressure plate 34 is annular and extends in the circumferential direction. The pressure plate 34 is configured to press the friction plate 32. The pressure plate 34 presses the friction plate 32 via the second friction material 33b. The pressure plate 34 is disposed between the second friction material 33b and the disc spring 35 in the axial direction.

[0047] The pressure plate 34 is configured to rotate integrally with the base portion 311. Specifically, the pressure plate 34 has a main body portion 341 and a plurality of engaging claws 342. The main body portion 341 is annular and extends in the circumferential direction. Each engaging claw 342 extends from the inner circumferential end of the main body portion 341 to a second side in the axial direction. Each engaging claw 342 engages with a corresponding engaging hole 311b. That is, each engaging claw 342 extends within each engaging hole 311b. Therefore, the pressure plate 34 rotates integrally with the base portion 311. The pressure plate 34 is movable in the axial direction relative to the base portion 311.

[0048] <Disc spring> The disc spring 35 is disposed between the base portion 311 and the pressure plate 34 in the axial direction. The disc spring 35 urges the pressure plate 34 toward the friction plate 32. That is, the disc spring 35 urges the pressure plate 34 toward the first side in the axial direction. As a result, the friction plate 32, the first friction material 33a, and the second friction material 33b are sandwiched between the pressure plate 34 and the support portion 312.

[0049] The disc spring 35 is annular and extends in the circumferential direction. The disc spring 35 has an outer peripheral end and an inner peripheral end. The disc spring 35 abuts against the base portion 311 at its outer peripheral end and against the pressure plate 34 at its inner peripheral end. The outer diameter of the disc spring 35 is larger than the outer diameter of the pressure plate 34. Therefore, the disc spring 35 is exposed to the first axial side through the screw hole 312a of the support portion 312. In other words, the disc spring 35 faces the screw hole 312a in the axial direction.

[0050] <First fastening member> The first fastening member 5 fastens the friction plate 32 and the input rotor 41. More specifically, the first fastening member 5 fastens the friction plate 32 and the second input plate 41b. The first fastening member 5 is disposed so as to be exposed to the second axial side through the through hole 311a. That is, the first fastening member 5 faces the through hole 311a in the axial direction. The through hole 311a is sized so that the entire first fastening member 5 is exposed when viewed in the axial direction. That is, the entire first fastening member 5 is exposed to the second axial side through the through hole 311a. The first fastening member 5 is also exposed to the first axial side. That is, each member constituting the damper unit 4 has a through hole or a notch so as not to overlap with the first fastening member 5 when viewed in the axial direction. The first fastening member 5 is, for example, a rivet.

[0051] <Manufacturing method> Next, a method for manufacturing the power transmission device 100 configured as described above will be described. First, as shown in Fig. 3, the torque limiter unit 3 and the damper unit 4 are assembled separately. Then, the assembled torque limiter unit 3 and damper unit 4 are combined with each other.

[0052] More specifically, the friction plate 32 of the torque limiter unit 3 and the input rotor 41 (particularly the second input plate 41b) of the damper unit 4 are fastened together by the first fastening member 5. At this time, the fastening operation using the first fastening member 5 (for example, the operation of crushing the head of the first fastening member 5) is performed via the through-hole 311a formed in the base portion 311. The power transmission device 100 manufactured in this manner is attached to the crankshaft by the bolt 101.

[0053] When the power transmission device 100 manufactured as described above is used, the torque limiter function of the torque limiter unit 3 is activated, causing relative rotation between the torque limiter unit 3 and the damper unit 4, resulting in misalignment of the first fastening member 5 and the through hole 311a. In other words, the first fastening member 5 may not be exposed to the second axial side through the through hole 311a. For this reason, when disassembling the power transmission device 100 for maintenance or the like, it is necessary to align the first fastening member 5 with the through hole 311a.

[0054] 4, first, the bolt 103 is screwed into the screw hole 312a of the support portion 312, and the tip surface of the bolt 103 presses the disc spring 35 in the second axial direction. That is, the bolt 103 presses the disc spring 35 in a direction away from the pressure plate 34. This releases the biasing force of the disc spring 35 against the pressure plate 34, and also releases the pressure plate 34 from sandwiching the friction plate 32. As a result, the damper unit 4 can be easily rotated relative to the torque limiter unit 3, and ultimately the first fastening member 5 can be aligned with the through hole 311a.

[0055] [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.

[0056] (a) In the above embodiment, the friction plate 32 is frictionally engaged with the support portion 312, but the configuration of the friction plate 32 is not limited to this. For example, the friction plate 32 may be frictionally engaged with the base portion 311. That is, the friction plate 32 may be frictionally engaged with the base portion 311 via the second friction material 33b. In this case, the pressure plate 34 is disposed between the support portion 312 and the friction plate 32, and the disc spring 35 is disposed between the support portion 312 and the pressure plate 34. The disc spring 35 biases the pressure plate 34 toward the second axial side.

[0057] (b) In the above embodiment, the support portion 312 is configured as a separate member from the base portion 311, but the configuration of the flywheel 31 is not limited to this. For example, the support portion 312 may be integrally formed with the base portion 311 as a single member.

[0058] (c) The disc springs 35 do not have to be exposed from the screw holes 312a. In this case, the pressure plate 34 can be configured to be exposed from the screw holes 312a. By pressing the pressure plate 34 with the bolts 103, the biasing force of the disc springs 35 against the friction plate 32 is nullified, and the damper unit 4 can be easily rotated relative to the torque limiter unit 3. [Explanation of symbols]

[0059] 3: Torque limiter unit 31: Flywheel 311: Base part 311a: Through hole 311b: Engagement hole 312: Support Department 312a: screw hole 32: Friction plate 34: Pressure plate 341: Main body 342: Engagement claw 35: Disc spring 4: Damper unit 41: Input rotor 41a: First input plate 41b: Second input plate 41c: Second fastening member 42: Output rotor 43: Elastic member 5: First fastening member 100: Power transmission device

Claims

1. a torque limiter unit; A damper unit; a first fastening member; Equipped with The torque limiter unit is a flywheel having a base portion including a through hole passing through in an axial direction, and a support portion disposed on a first axial side with a gap between the base portion and the support portion; a friction plate disposed between the base portion and the support portion; a pressure plate that presses the friction plate; a biasing member that biases the pressure plate toward the friction plate; and The damper unit includes: an input rotor configured to rotate integrally with the friction plate; an output rotor arranged to be rotatable relative to the input rotor; an elastic member that elastically connects the input rotor and the output rotor; and the first fastening member fastens the friction plate and the input rotating body and is disposed so as to be exposed in the axial direction through the through hole. Power transmission device.

2. the input rotor includes a pair of input plates and second fastening members that fasten the pair of input plates to outer peripheries of the pair of input plates, The second fastening member is disposed on a first axial side of the support portion and overlaps with the support portion as viewed in the axial direction. The power transmission device according to claim 1 .

3. The base portion has an engagement hole, The pressure plate has an engagement claw that engages with the engagement hole. The power transmission device according to claim 1 .

4. the pressure plate has an annular body portion, The engagement claw extends from an inner peripheral end of the main body portion toward a second axial side. The power transmission device according to claim 3 .

5. The biasing member is a disc spring, The biasing member has an inner peripheral end portion that contacts the pressure plate and an outer peripheral end portion that contacts the base portion.

5. The power transmission device according to claim 4.

6. The friction plate is sandwiched between the support portion and the pressure plate. The power transmission device according to claim 1 .

7. The support portion has a screw hole passing through in the axial direction, The biasing member is exposed in the axial direction through the screw hole. The power transmission device according to claim 1 .

8. 10. A method for manufacturing the power transmission device of claim 1, comprising: assembling the torque limiter unit; assembling the damper unit; fastening the friction plate and the input rotating body through the through hole; A method for manufacturing a power transmission device, comprising:

Images