Torque limiter

Abstract

To provide a torque limiter capable of achieving miniaturization.SOLUTION: A torque limiter includes a first cover plate, a second cover plate, a transmission member, a pressure plate, a plurality of disc springs, and a friction generating part. The second cover plate is disposed spaced apart from the first cover plate in an axial direction. The transmission member is disposed between the first cover plate and the second cover plate. The pressure plate is arranged between the second cover plate and the transmission member. Each of the disc springs is arranged between the pressure plate and the second cover plate. Each of the disc springs energizes the pressure plate toward the transmission member. The disc springs are stacked in parallel. The friction generating part is disposed in at least one of the positions between the first cover plate and the transmission member and between the pressure plate and the transmission member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a torque limiter. [Background technology]

[0002] A torque limiter is used to block the transmission of torque above a predetermined value. For example, Patent Document 1 discloses a torque limiter disposed between a flywheel and a damper device. In this torque limiter, a pressing plate is pressed against a lining plate by the biasing force of a disc spring, and the pressing plate and the lining plate are frictionally engaged. This makes it possible to block the transmission of torque above a predetermined value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-011159 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a smaller torque limiter due to the space required to install the torque limiter, but when the torque limiter is made smaller, the diameter of the disc spring also becomes smaller, resulting in a problem of insufficient pressing load from the disc spring.

[0005] An object of the present invention is to provide a torque limiter that can be made compact. [Means for solving the problem]

[0006] The torque limiter according to the first aspect includes a first cover plate, a second cover plate, a transmission member, a pressure plate, a plurality of disc springs, and a friction generating portion. The second cover plate is disposed at an axial distance from the first cover plate. The transmission member is disposed between the first cover plate and the second cover plate. The pressure plate is disposed between the second cover plate and the transmission member. Each disc spring is disposed between the pressure plate and the second cover plate. Each disc spring biases the pressure plate toward the transmission member. Each disc spring is stacked in parallel. The friction generating portion is disposed at least one of between the first cover plate and the transmission member and between the pressure plate and the transmission member.

[0007] According to this configuration, since a plurality of disc springs stacked in parallel are used, the pressing load of the disc springs can be increased, and therefore the torque limiter can be made smaller without causing a shortage of the pressing load of the disc springs.

[0008] The torque limiter according to the second aspect is the torque limiter according to the first aspect, and is configured as follows: Of the plurality of disc springs, the disc spring that comes into contact with the pressure plate abuts against the pressure plate at an outer peripheral end portion.

[0009] The torque limiter according to the third aspect is the torque limiter according to the first or second aspect, and is configured as follows: Of the plurality of disc springs, the disc spring that abuts against the second cover plate abuts against the second cover plate at an inner peripheral end portion.

[0010] A torque limiter according to a fourth aspect is the torque limiter according to any one of the first to third aspects, further comprising a thrust bearing. The thrust bearing is disposed axially between the transmission member and the second cover plate.

[0011] A torque limiter according to a fifth aspect is the torque limiter according to any one of the first to fourth aspects, and is configured as follows: The pressure plate has a pressing portion and an extending portion. The pressing portion is disposed between the transmission member and the disc spring in the axial direction. The pressing portion is annular. The extending portion extends in the axial direction from an inner peripheral end of the pressing portion toward the second cover plate. The disc spring is disposed radially outward from the extending portion.

[0012] A torque limiter according to a sixth aspect is the torque limiter according to any one of the first to fifth aspects, and is configured as follows: the friction generating portion has a first friction material and a second friction material. The first friction material is disposed between the first cover plate and the transmission member. The second friction material is disposed between the pressure plate and the transmission member.

[0013] A torque limiter according to a seventh aspect is the torque limiter according to the sixth aspect, and is configured as follows: The transmission member has a flange portion. The flange portion has an outer circumferential portion and an inner circumferential portion. The first and second friction materials are attached to the outer circumferential portion. The inner circumferential portion is thicker than the outer circumferential portion.

[0014] A torque limiter according to an eighth aspect is the torque limiter according to the seventh aspect, and is configured as follows: The first cover plate has a protruding portion that protrudes toward an inner periphery of the flange portion.

[0015] A torque limiter according to a ninth aspect is the torque limiter according to the seventh or eighth aspect, and is configured as follows: The pressure plate has a protruding portion. The protruding portion protrudes toward an inner periphery of the flange portion.

[0016] A torque limiter according to a tenth aspect is the torque limiter according to any one of the first to ninth aspects, and is configured as follows: the transmission member has a cylindrical portion and a flange portion. The flange portion extends radially outward from the cylindrical portion. The cylindrical portion has a spline hole extending in the axial direction.

[0017] A torque limiter according to an eleventh aspect is the torque limiter according to any one of the first to tenth aspects, and is configured as follows. The second cover plate has a cover main body and a cylindrical portion. The cover main body faces the disc spring in the axial direction. The cylindrical portion extends in the axial direction from an inner peripheral end of the cover main body. The cylindrical portion has a gear portion on an outer peripheral surface. Effect of the Invention

[0018] According to the present invention, the torque limiter can be made smaller. [Brief description of the drawings]

[0019] [Figure 1] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The torque limiter 100 according to this embodiment will be described below 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 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.

[0021] As shown in FIG. 1, the torque limiter 100 is arranged to be rotatable around a rotation axis O. The torque limiter 100 is configured to block the transmission of torque equal to or greater than a predetermined value. The torque limiter 100 has a first cover plate 2, a second cover plate 3, a transmission member 4, a friction generating portion 5, a pressure plate 6, a first disc spring 7a, a second disc spring 7b, and a thrust bearing 8. The torque limiter 100 is arranged, for example, in a transmission. The torque limiter 100 is, for example, a wet type. In this embodiment, torque is input from the transmission member 4, and torque is output from the second cover plate 3.

[0022] <First cover plate> The first cover plate 2 is disposed to be rotatable about a rotation axis O. The first cover plate 2 has a first cover main body portion 21, a first cylindrical portion 22, an attachment portion 23, and a first protruding portion 24.

[0023] The first cover body portion 21 is annular and extends in the circumferential direction. The first cylindrical portion 22 extends in the axial direction from the outer circumferential end portion of the first cover body portion 21. In detail, the first cylindrical portion 22 extends from the first cover body portion 21 toward the second cover plate 3.

[0024] The attachment portion 23 extends radially outward from the tip end of the first cylindrical portion 22. The attachment portion 23 is annular and extends in the circumferential direction. The first cover plate 2 is attached to the second cover plate 3 at the attachment portion 23.

[0025] The first protruding portion 24 protrudes from an inner periphery of the first cover main body portion 21 toward the transmitting member 4 in the axial direction. The first protruding portion 24 is annular and extends in the circumferential direction. The first protruding portion 24 protrudes toward an inner periphery 422 of the flange portion 42, which will be described later. The first protruding portion 24 faces the inner periphery 422 in the axial direction. In addition, the first protruding portion 24 faces the inner periphery 422 with a gap therebetween.

[0026] <Second cover plate> The second cover plate 3 is disposed at an interval in the axial direction from the first cover plate 2. In detail, the second cover plate 3 is disposed at an interval in the axial direction from the first cover body portion 21 of the first cover plate 2.

[0027] The second cover plate 3 is arranged rotatably about a rotation axis O. The second cover plate 3 is configured to rotate integrally with the first cover plate 2. The second cover plate 3 is fixed to the first cover plate 2 at an outer circumferential end portion. In detail, the second cover plate 3 is fixed to the mounting portion 23 of the first cover plate 2. The second cover plate 3 is fixed to the first cover plate 2 by a rivet 101.

[0028] The second cover plate 3 has a second cover body portion 31 and a second cylindrical portion 32. The second cover body portion 31 is annular and extends in the circumferential direction. The second cover body portion 31 is disposed at an interval from the first cover body portion 21 in the axial direction. Various members are disposed between the first cover body portion 21 and the second cover body portion 31. The second cover body portion 31 has an inner diameter smaller than that of the first cover body portion 21. The second cover body portion 31 faces the second disc spring 7b in the axial direction.

[0029] The second cylindrical portion 32 extends in the axial direction from the inner peripheral end of the second cover main body portion 31. More specifically, the second cylindrical portion 32 extends in a direction away from the first cover plate 2. The second cylindrical portion 32 has a gear portion 321 on its outer peripheral surface, and a gear (not shown) meshes with this gear portion 321. The torque limiter 100 outputs torque via this gear portion 321.

[0030] <Transmission components> The transmission member 4 is disposed rotatably about a rotation axis O. The transmission member 4 is disposed between the first cover plate 2 and the second cover plate 3 in the axial direction. The transmission member 4 has a third cylindrical portion 41 and a flange portion 42.

[0031] The third cylindrical portion 41 has a splined hole 411. The splined hole 411 extends in the axial direction. A shaft (not shown) is spline-fitted into this splined hole 411. Therefore, torque is transmitted from the shaft to the transmission member 4. That is, torque is input to the torque limiter 100 via the transmission member 4.

[0032] The inner diameter of the third cylindrical portion 41 is larger than the inner diameter of the second cylindrical portion 32. The inner diameter of the third cylindrical portion 41 may be smaller than the inner diameter of the second cylindrical portion 32. The outer diameter of the third cylindrical portion 41 is larger than the outer diameter of the second cylindrical portion 32. The outer diameter of the third cylindrical portion 41 may be smaller than the outer diameter of the second cylindrical portion 32.

[0033] The flange portion 42 extends radially outward from the outer circumferential surface of the third cylindrical portion 41. The flange portion 42 is disposed between the first cover plate 2 and the second cover plate 3 in the axial direction. In detail, the flange portion 42 is disposed between the first cover main body portion 21 and the second cover main body portion 31 in the axial direction. The third cylindrical portion 41 is disposed radially inward with respect to the first cover main body portion 21.

[0034] The flange portion 42 has an outer circumferential portion 421 and an inner circumferential portion 422. The inner circumferential portion 422 is configured to be thicker than the outer circumferential portion 421. In detail, the inner circumferential portion 422 protrudes on both sides in the axial direction relative to the outer circumferential portion 421.

[0035] <Friction generating part> The friction generating portion 5 has a first friction material 5a and a second friction material 5b. The first friction material 5a is disposed between the first cover plate 2 and the transmission member 4 in the axial direction. More specifically, the first friction material 5a is disposed between the first cover body portion 21 and the flange portion 42. The first friction material 5a is fixed to the transmission member 4. More specifically, the first friction material 5a is fixed to the outer circumferential portion 421 of the flange portion 42 of the transmission member 4. For example, the first friction material 5a is fixed to the outer circumferential portion 421 by an adhesive. The first friction material 5a is in contact with the first cover plate 2. More specifically, the first friction material 5a is in contact with the first cover body portion 21.

[0036] The second friction material 5b is disposed between the transmission member 4 and the pressure plate 6 in the axial direction. More specifically, the second friction material 5b is disposed between the flange portion 42 and a pressing portion 61, which will be described later. The second friction material 5b is fixed to the transmission member 4. More specifically, the second friction material 5b is fixed to an outer circumferential portion 421 of the flange portion 42 of the transmission member 4. For example, the second friction material 5b is fixed to the outer circumferential portion 421 by an adhesive. The second friction material 5b is in contact with the pressure plate 6. More specifically, the second friction material 5b is in contact with the pressing portion 61, which will be described later.

[0037] <Pressure plate> The pressure plate 6 is disposed rotatably about a rotation axis O. The pressure plate 6 is disposed between the second cover plate 3 and the transmission member 4 in the axial direction. The pressure plate 6 has a pressing portion 61, a plurality of extending portions 62, and a second protruding portion 63.

[0038] The pressing portion 61 is annular and extends in the circumferential direction. The pressing portion 61 is disposed between the first disc spring 7a and the flange portion 42 in the axial direction. The pressing portion 61 faces the second friction material 5b in the axial direction. The pressing portion 61 overlaps with the first cover body portion 21, the first friction material 5a, the flange portion 42, and the second friction material 5b when viewed in the axial direction.

[0039] The extension portion 62 extends in the axial direction from the inner peripheral end of the pressing portion 61 toward the second cover plate 3. The extension portions 62 are arranged at intervals from one another in the circumferential direction. The tip portions of the extension portions 62 are inserted into the through holes 311 formed in the second cover body portion 31 of the second cover plate 3. Therefore, the pressure plate 6 rotates integrally with the second cover plate 3.

[0040] The second protruding portion 63 protrudes from the inner periphery of the pressing portion 61 toward the inner periphery 422 of the flange portion 42 in the axial direction. The second protruding portion 63 faces the inner periphery 422 in the axial direction. The second protruding portion 63 is disposed at a distance from the inner periphery 422. The second protruding portion 63 is annular and extends in the circumferential direction. The second protruding portion 63 overlaps with the first protruding portion 24 when viewed in the axial direction.

[0041] <First and second disc springs> The first and second disc springs 7a, 7b are arranged rotatably around a rotation axis O. The first and second disc springs 7a, 7b are stacked in parallel. The first and second disc springs 7a, 7b are arranged between the pressure plate 6 and the second cover plate 3 in the axial direction. In detail, the first and second disc springs 7a, 7b are arranged between the pressing portion 61 and the second cover main body portion 31 in the axial direction.

[0042] The first and second disc springs 7a, 7b are disposed radially outward from the extending portion 62. The first and second disc springs 7a, 7b are disposed radially at a distance from the extending portion 62. In addition, the first and second disc springs 7a, 7b are disposed radially inward from the first cylindrical portion 22. In other words, the first and second disc springs 7a, 7b are surrounded by the pressing portion 61, the extending portion 62, the first cylindrical portion 22, and the second cover main body portion 31.

[0043] The first and second disc springs 7a, 7b urge the pressure plate 6 in the axial direction toward the transmission member 4. As a result, the first cover plate 2 and the pressure plate 6 frictionally engage with the transmission member 4 via the first and second friction materials 5a, 5b.

[0044] The first disc spring 7a contacts the pressure plate 6, and the second disc spring 7b contacts the second cover plate 3. The first disc spring 7a contacts the pressure plate 6 at its outer circumferential end. The second disc spring 7b contacts the second cover plate 3 at its inner circumferential end.

[0045] The first and second disc springs 7a, 7b are the same disc springs. That is, the first and second disc springs 7a, 7b have the same material, size, and characteristics. The first and second disc springs 7a, 7b may have different materials, sizes, and characteristics.

[0046] <Thrust bearing> The thrust bearing 8 is disposed axially between the transmission member 4 and the second cover plate 3. In detail, the thrust bearing 8 is disposed between the second cylindrical portion 32 and the third cylindrical portion 41.

[0047] <Operation> In the torque limiter 100 configured as described above, when torque less than a predetermined value is input, the torque is transmitted in the following order: transmission member 4, first friction material 5a, first cover plate 2, and second cover plate 3. On the other hand, when torque equal to or greater than a predetermined value is input to the transmission member 4, the transmission member 4 and the first cover plate 2 rotate relative to each other, and the transmission of the torque is interrupted.

[0048] [Variations] Although the embodiment of the present invention has 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.

[0049] (a) In the above embodiment, the torque limiter 100 has two disc springs, but may have three or more disc springs.

[0050] (b) In the above embodiment, torque is input from the transmission member 4 and output from the second cover plate 3, but the torque transmission path may be reversed. That is, torque may be input from the second cover plate 3 and output from the transmission member 4.

[0051] (c) In the above embodiment, the torque limiter 100 is disposed inside the transmission, but the torque limiter 100 does not have to be disposed inside the transmission. Also, in the above embodiment, the torque limiter 100 is a wet type, but it may be a dry type.

[0052] (d) The extension portion 62 of the pressure plate 6 and the first and second disc springs 7a, 7b may be engaged with each other. Specifically, a recess may be formed on one of the extension portion 62 and the first and second disc springs 7a, 7b, and a protrusion may be formed on the other, and the protrusion and the recess may be engaged with each other. This makes it possible to prevent relative rotation between the pressure plate 6 and the first and second disc springs 7a, 7b.

[0053] (e) In the above embodiment, the friction generating portion 5 has the first and second friction materials 5a, 5b, but the configuration of the friction generating portion 5 is not limited to this. For example, the friction generating portion 5 may have only the first friction material 5a or only the second friction material 5b. In other words, the friction generating portion 5 may be disposed only between the first cover plate 2 and the transmission member 4, or only between the pressure plate 6 and the transmission member 4.

[0054] Furthermore, the friction generating portion 5 does not have to have the first friction material 5a and the second friction material 5b. In this case, the friction generating portion 5 may be formed directly on the transmission member 4, the first cover plate 2, and the pressure plate 6. That is, the friction generating portion 5 may be formed by the first cover plate 2 and the transmission member 4 coming into contact with each other and frictionally engaging with each other. The friction generating portion 5 may also be formed by the pressure plate 6 and the transmission member 4 coming into contact with each other and frictionally engaging with each other. [Explanation of symbols]

[0055] 2: First cover plate 24: 1st protrusion 3: Second cover plate 32: Second cylindrical section 321: Gear section 4: Transmission parts 41: Third cylindrical section 411: Spline hole 42: Flange part 421: Outer periphery 422: Inner circumference 5: Friction area 5a: 1st friction material 5b:Second friction material 6: Pressure plate 61: Pressing part 62: Extension part 63:Second protrusion 7a: First disc spring 7b: Second disc spring 8: Thrust bearing 100: Torque limiter

Claims

1. A first cover plate; a second cover plate disposed axially apart from the first cover plate; A transmission member disposed between the first cover plate and the second cover plate; a pressure plate disposed between the second cover plate and the transmission member; a plurality of disc springs arranged in parallel and stacked on one another and disposed between the pressure plate and the second cover plate, the disc springs biasing the pressure plate toward the transmission member; a friction generating portion disposed at least one of between the first cover plate and the transmission member and between the pressure plate and the transmission member; A torque limiter.

2. Among the plurality of disc springs, a disc spring that contacts the pressure plate abuts against the pressure plate at an outer peripheral end portion.

2. The torque limiter according to claim 1.

3. Among the plurality of disc springs, the disc spring that abuts against the second cover plate abuts against the second cover plate at an inner peripheral end portion.

2. The torque limiter according to claim 1.

4. Further comprising a thrust bearing disposed between the transmission member and the second cover plate in the axial direction.

2. The torque limiter according to claim 1.

5. the pressure plate has an annular pressing portion that is disposed between the transmission member and the disc spring in the axial direction, and an extension portion that extends in the axial direction from an inner circumferential end portion of the pressing portion toward the second cover plate, The disc spring is disposed radially outward from the extension portion.

2. The torque limiter according to claim 1.

6. The friction generating portion is a first friction material disposed between the first cover plate and the transmission member; a second friction material disposed between the pressure plate and the transmission member; having 2. The torque limiter according to claim 1.

7. The transmission member has a flange portion, The flange portion has an outer circumferential portion to which the first and second friction materials are attached, and an inner circumferential portion that is thicker than the outer circumferential portion. The torque limiter according to claim 6.

8. The first cover plate has a protruding portion protruding toward an inner periphery of the flange portion. The torque limiter according to claim 7.

9. The pressure plate has a protruding portion protruding toward an inner periphery of the flange portion. The torque limiter according to claim 7.

10. The transmission member has a cylindrical portion and a flange portion extending radially outward from the cylindrical portion, The cylindrical portion has a spline hole extending in the axial direction.

2. The torque limiter according to claim 1.

11. The second cover plate has a cover body portion facing the disc spring in the axial direction and a cylindrical portion extending in the axial direction from an inner peripheral end portion of the cover body portion, The cylindrical portion has a gear portion on an outer circumferential surface.

2. The torque limiter according to claim 1.

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