Torque limiter

Abstract

The invention provides a torque limiter which can be miniaturized. The torque limiter includes a first cover plate, a second cover plate, a transmission member, a pressure plate, a plurality of belleville springs, and a friction generating portion. The second cover plate and the first cover plate are arranged at an interval in the axial direction. 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 belleville spring is arranged between the pressing plate and the second cover plate. Each of the belleville springs urges the pressure plate toward the transmission member. The belleville springs are stacked side by side. The friction generating portion is disposed between the first cover plate and the transmission member and / or between the pressure plate and the transmission member.

Description

Technical Field

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

[0002] A torque limiter is used to cut off the transmission of torque exceeding a predetermined value. For example, Patent Document 1 discloses a torque limiter disposed between a flywheel and a vibration reduction device. In the torque limiter, a pressing plate is pressed against a lining plate by the force of a disc spring so that the pressing plate and the lining plate are frictionally engaged. Therefore, the transmission of torque exceeding a predetermined value can be cut off.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-011159 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] There is a demand for miniaturization of the torque limiter due to the location where the torque limiter is installed. However, if the torque limiter is miniaturized, the diameter of the disc spring also becomes smaller, and there is a problem that the pressing load of the disc spring is insufficient.

[0008] The technical problem of the present invention is to provide a torque limiter which can be miniaturized.

[0009] Solutions for solving problems

[0010] The torque limiter involved in the first aspect comprises a first cover plate, a second cover plate, a transmission component, a pressure plate, a plurality of disc springs, and a friction generating portion. The second cover plate is spaced apart from the first cover plate in the axial direction. The transmission component is arranged between the first cover plate and the second cover plate. The pressure plate is arranged between the second cover plate and the transmission component. Each disc spring is arranged between the pressure plate and the second cover plate. Each disc spring applies force to the pressure plate toward the transmission component. Each disc spring is stacked in parallel. The friction generating portion is arranged between the first cover plate and the transmission component and between the pressure plate and the transmission component.

[0011] 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. Therefore, the torque limiter can be miniaturized without causing the pressing load of the disc springs to be insufficient.

[0012] In the torque limiter according to the first aspect, the torque limiter according to the second aspect is configured as follows: The disc springs in contact with the pressure plate among the plurality of disc springs abut against the pressure plate at their outer peripheral ends.

[0013] In the torque limiter according to the first or second aspect, a torque limiter according to a third aspect is configured as follows: The disc springs that come into contact with the second cover plate among the plurality of disc springs come into contact with the second cover plate at their inner peripheral ends.

[0014] In the torque limiter according to any one of the first to third aspects, the torque limiter according to the fourth aspect further includes a thrust bearing. The thrust bearing is arranged between the transmission member and the second cover plate in the axial direction.

[0015] In the torque limiter involved in any one of the first to fourth aspects, the torque limiter involved in the fifth aspect is configured as follows. The pressure plate has a pressing portion and an extension portion. The pressing portion is axially arranged between the transmission component and the disc spring. The pressing portion is annular. The extension portion extends axially from the inner peripheral end of the pressing portion toward the second cover plate. The disc spring is arranged radially outward relative to the extension portion.

[0016] In the torque limiter according to any one of the first to fifth aspects, the torque limiter according to the sixth aspect is configured as follows: the friction generating portion has a first friction member and a second friction member. The first friction member is arranged between the first cover plate and the transmission member. The second friction member is arranged between the pressure plate and the transmission member.

[0017] In the torque limiter according to the sixth aspect, the torque limiter according to the seventh aspect is configured as follows: the transmission member has a flange portion. The flange portion has an outer peripheral portion and an inner peripheral portion. The first friction member and the second friction member are mounted on the outer peripheral portion. The inner peripheral portion is thicker than the outer peripheral portion.

[0018] In the torque limiter according to claim 7, the torque limiter according to claim 8 is configured as follows: The first cover plate has a protruding portion. The protruding portion protrudes toward the inner peripheral portion of the flange portion.

[0019] In the torque limiter according to the seventh or eighth aspect, a torque limiter according to a ninth aspect is configured as follows: the pressure plate has a protrusion, and the protrusion protrudes toward the inner peripheral portion of the flange portion.

[0020] In the torque limiter according to any one of the first to ninth aspects, the torque limiter according to the tenth aspect 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.

[0021] In the torque limiter involved in any one of the first to tenth aspects, the torque limiter involved in the eleventh aspect is constructed as follows. The second cover plate has a cover body and a cylindrical portion. The cover body is axially opposed to the disc spring. The cylindrical portion extends axially from the inner peripheral end of the cover body. The cylindrical portion has a gear portion on the outer peripheral surface.

[0022] Effects of the Invention

[0023] According to the present invention, the torque limiter can be reduced in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a cross-sectional view of the torque limiter. DETAILED DESCRIPTION

[0025] The torque limiter 100 according to the present embodiment will be described below with reference to the drawings. It should be noted that in the following description, the axial direction refers to the direction in which the rotation axis O of the torque limiter 100 extends. In addition, the circumferential direction refers to the circumferential direction of a circle with the rotation axis O as the center, and the radial direction refers to the radial direction of a circle with the rotation axis O as the center.

[0026] like Figure 1 As shown, the torque limiter 100 is configured to be rotatable around the rotation axis O. The torque limiter 100 is configured to cut off the transmission of torque above a predetermined value. The torque limiter 100 includes a first cover plate 2, a second cover plate 3, a transmission component 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, for example, configured in a transmission. The torque limiter 100 is, for example, a wet type. In this embodiment, torque is input from the transmission component 4, and torque is output from the second cover plate 3.

[0027] <First cover>

[0028] The first cover plate 2 is arranged to be rotatable about a rotation axis O. The first cover plate 2 includes a first cover body portion 21 , a first cylindrical portion 22 , a mounting portion 23 , and a first protruding portion 24 .

[0029] The first cover body 21 is annular and extends in the circumferential direction. The first cylindrical portion 22 extends in the axial direction from the outer peripheral end of the first cover body 21. Specifically, the first cylindrical portion 22 extends from the first cover body 21 toward the second cover plate 3.

[0030] The mounting portion 23 extends radially outward from the front end of the first cylindrical portion 22. The mounting portion 23 is annular and extends in the circumferential direction. The first cover plate 2 is mounted to the second cover plate 3 at the mounting portion 23.

[0031] The first protrusion 24 protrudes from the inner peripheral portion of the first cover body 21 toward the transmission member 4 in the axial direction. The first protrusion 24 is annular and extends in the circumferential direction. The first protrusion 24 protrudes toward the inner peripheral portion 422 of the flange portion 42 described later. The first protrusion 24 is opposite to the inner peripheral portion 422 in the axial direction. In addition, the first protrusion 24 and the inner peripheral portion 422 are opposite to each other with a gap therebetween.

[0032] <Second cover>

[0033] The second cover plate 3 is disposed at a distance from the first cover plate 2 in the axial direction. Specifically, the second cover plate is disposed at a distance from the first cover body portion 21 of the first cover plate 2 in the axial direction.

[0034] The second cover plate 3 is configured to be rotatable around the 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 the outer peripheral end. 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.

[0035] 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 spaced apart from the first cover body portion 21 in the axial direction. Each component is arranged between the first cover body portion 21 and the second cover body portion 31. The inner diameter of the second cover body portion 31 is smaller than the inner diameter of the first cover body portion 21. The second cover body portion 31 is opposed to the second disc spring 7b in the axial direction.

[0036] The second cylindrical portion 32 extends from the inner peripheral end of the second cover body portion 31 in the axial direction. 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 the outer peripheral surface. A gear (not shown) meshes with the gear portion 321. The torque limiter 100 outputs torque via the gear portion 321.

[0037] <Transmission parts>

[0038] The transmission member 4 is disposed so as to be rotatable about the 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 includes a third cylindrical portion 41 and a flange portion 42 .

[0039] The third cylindrical portion 41 has a spline hole 411 . The spline hole 411 extends in the axial direction. A shaft (not shown) is spline-fitted into the spline hole 411 . Therefore, the torque is transmitted from the shaft to the transmission member 4 . That is, the torque is input to the torque limiter 100 via the transmission member 4 .

[0040] The inner diameter of the third cylindrical portion 41 is larger than the inner diameter of the second cylindrical portion 32. It should be noted that the inner diameter of the third cylindrical portion 41 may also be smaller than the inner diameter of the second cylindrical portion 32. In addition, the outer diameter of the third cylindrical portion 41 is larger than the outer diameter of the second cylindrical portion 32. It should be noted that the outer diameter of the third cylindrical portion 41 may also be smaller than the outer diameter of the second cylindrical portion 32.

[0041] The flange portion 42 extends radially outward from the outer peripheral surface of the third cylindrical portion 41. The flange portion 42 is axially arranged between the first cover plate 2 and the second cover plate 3. Specifically, the flange portion 42 is axially arranged between the first cover body portion 21 and the second cover body portion 31. The third cylindrical portion 41 is arranged radially inward relative to the first cover body portion 21.

[0042] The flange portion 42 has an outer peripheral portion 421 and an inner peripheral portion 422. The inner peripheral portion 422 is configured to be thicker than the outer peripheral portion 421. Specifically, the inner peripheral portion 422 protrudes to both sides in the axial direction with respect to the outer peripheral portion 421.

[0043] <Friction generating part>

[0044] The friction generating portion 5 includes a first friction member 5a and a second friction member 5b. The first friction member 5a is arranged between the first cover plate 2 and the transmission member 4 in the axial direction. In detail, the first friction member 5a is arranged between the first cover body portion 21 and the flange portion 42. The first friction member 5a is fixed to the transmission member 4. In detail, the first friction member 5a is fixed to the outer peripheral portion 421 of the flange portion 42 of the transmission member 4. For example, the first friction member 5a is fixed to the outer peripheral portion 421 by an adhesive. The first friction member 5a is in contact with the first cover plate 2. In detail, the first friction member 5a is in contact with the first cover body portion 21.

[0045] The second friction member 5b is arranged between the transmission member 4 and the pressure plate 6 in the axial direction. Specifically, the second friction member 5b is arranged between the flange portion 42 and the pressing portion 61 described later. The second friction member 5b is fixed to the transmission member 4. Specifically, the second friction member 5b is fixed to the outer peripheral portion 421 of the flange portion 42 of the transmission member 4. For example, the second friction member 5b is fixed to the outer peripheral portion 421 by an adhesive. The second friction member 5b is in contact with the pressure plate 6. Specifically, the second friction member 5b is in contact with the pressing portion 61 described later.

[0046] <Press plate>

[0047] The pressure plate 6 is disposed rotatably about the 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 extended portions 62 , and a second protruding portion 63 .

[0048] The pressing portion 61 is annular and extends in the circumferential direction. The pressing portion 61 is axially disposed between the first disc spring 7a and the flange portion 42. The pressing portion 61 is axially opposed to the second friction member 5b. When viewed in the axial direction, the pressing portion 61 overlaps with the first cover body 21, the first friction member 5a, the flange portion 42, and the second friction member 5b.

[0049] The extension portion 62 extends axially 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 each other in the circumferential direction. The front end of the extension portion 62 is inserted into the through hole 311 formed in the second cover body portion 31 of the second cover plate 3. Therefore, the pressing plate 6 rotates integrally with the second cover plate 3.

[0050] The second protrusion 63 protrudes from the inner circumference of the pressing portion 61 toward the inner circumference 422 of the flange portion 42 in the axial direction. The second protrusion 63 is axially opposed to the inner circumference 422. The second protrusion 63 is spaced apart from the inner circumference 422. The second protrusion 63 is annular and extends in the circumferential direction. When viewed in the axial direction, the second protrusion 63 overlaps with the first protrusion 24.

[0051] <First disc spring and second disc spring>

[0052] The first disc spring 7a and the second disc spring 7b are configured to be rotatable around the rotation axis O. The first disc spring 7a and the second disc spring 7b are stacked in parallel. The first disc spring 7a and the second disc spring 7b are axially arranged between the pressure plate 6 and the second cover plate 3. In detail, the first disc spring 7a and the second disc spring 7b are axially arranged between the pressing portion 61 and the second cover body portion 31.

[0053] The first disc spring 7a and the second disc spring 7b are arranged radially outward relative to the extension portion 62. The first disc spring 7a and the second disc spring 7b are arranged radially spaced apart from the extension portion 62. In addition, the first disc spring 7a and the second disc spring 7b are arranged radially inward relative to the first cylindrical portion 22. That is, the first disc spring 7a and the second disc spring 7b are surrounded by the pressing portion 61, the extension portion 62, the first cylindrical portion 22, and the second cover body portion 31.

[0054] The first disc spring 7a and the second disc spring 7b axially urge the pressure plate 6 toward the transmission member 4. As a result, the first cover plate 2 and the pressure plate 6 are frictionally engaged with the transmission member 4 via the first friction material 5a and the second friction material 5b.

[0055] 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 the outer peripheral end. The second disc spring 7b contacts the second cover plate 3 at the inner peripheral end.

[0056] The first disc spring 7a and the second disc spring 7b are identical disc springs. That is, the materials, sizes and characteristics of the first disc spring 7a and the second disc spring 7b are identical. It should be noted that the first disc spring 7a and the second disc spring 7b may also have different materials, sizes and characteristics.

[0057] <Thrust bearing>

[0058] The thrust bearing 8 is disposed between the transmission member 4 and the second cover plate 3 in the axial direction. Specifically, the thrust bearing 8 is disposed between the second cylindrical portion 32 and the third cylindrical portion 41 .

[0059] <Action>

[0060] In the torque limiter 100 configured as described above, when a torque less than a predetermined value is input, the torque is transmitted in the order of the transmission member 4, the first friction member 5a, the first cover plate 2, and the second cover plate 3. On the other hand, when a torque 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 cut off.

[0061] [Variation example]

[0062] Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. It should be noted that the following modifications can basically be applied simultaneously.

[0063] (a) In the above embodiment, the torque limiter 100 includes two disc springs, but may include three or more disc springs.

[0064] (b) In the above embodiment, the 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, the torque may be input from the second cover plate 3 and output from the transmission member 4 .

[0065] (c) In the above embodiment, the torque limiter 100 is disposed in the transmission, but the torque limiter 100 may not be disposed in the transmission. In addition, in the above embodiment, the torque limiter 100 is a wet type, but it may be a dry type.

[0066] (d) The extension 62 of the pressure plate 6 and the first disc spring 7a and the second disc spring 7b may also be engaged with each other. Specifically, a concave portion may be formed on one of the extension 62 and the first disc spring 7a and the second disc spring 7b, and a convex portion may be formed on the other, and the convex portion and the concave portion may be engaged with each other. In this way, the pressure plate 6 and the first disc spring 7a and the second disc spring 7b can be prevented from rotating relative to each other.

[0067] (e) In the above embodiment, the friction generating portion 5 includes the first friction member 5a and the second friction member 5b, but the structure of the friction generating portion 5 is not limited thereto. For example, the friction generating portion 5 may include only the first friction member 5a or only the second friction member 5b. That is, the friction generating portion 5 may be disposed only between the first cover plate 2 and the transmission member 4, or may be disposed only between the pressure plate 6 and the transmission member 4.

[0068] In addition, the friction generating part 5 may not have the first friction member 5a and the second friction member 5b. In this case, the friction generating part 5 may be directly formed on the transmission member 4, the first cover plate 2 and the pressure plate 6. That is, the friction generating part 5 may be formed by the first cover plate 2 and the transmission member 4 contacting and frictionally engaging with each other. In addition, the friction generating part 5 may be formed by the pressure plate 6 and the transmission member 4 contacting and frictionally engaging with each other.

[0069] Description of Reference Numerals

[0070] 2: first cover plate; 24: first protrusion; 3: second cover plate; 32: second cylindrical portion; 321: gear portion; 4: transmission component; 41: third cylindrical portion; 411: spline hole; 42: flange portion; 421: outer peripheral portion; 422: inner peripheral portion; 5: friction generating portion; 5a: first friction member; 5b: second friction member; 6: pressure plate; 61: pressing portion; 62: extension portion; 63: second protrusion; 7a: first disc spring; 7b: second disc spring; 8: thrust bearing; 100: torque limiter.

Claims

1. A torque limiter, comprising: first cover plate; A second cover plate is disposed spaced apart from the first cover plate in the axial direction; A transmission component, disposed between the first cover plate and the second cover plate; A pressure plate, disposed between the second cover plate and the transmission component; a plurality of disc springs, arranged between the pressure plate and the second cover plate, and applying force to the pressure plate toward the transmission component, the plurality of disc springs being stacked in parallel; as well as 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.

2. The torque limiter according to claim 1, wherein: The disc springs in contact with the pressure plate among the plurality of disc springs abut against the pressure plate at their outer peripheral ends.

3. The torque limiter according to claim 1, wherein: The disc springs that come into contact with the second cover plate among the plurality of disc springs come into contact with the second cover plate at their inner peripheral ends.

4. The torque limiter according to claim 1, wherein: The torque limiter further includes a thrust bearing disposed between the transmission member and the second cover plate in the axial direction.

5. The torque limiter according to claim 1, wherein: The pressure plate includes: an annular pressing portion disposed between the transmission member and the disc spring in the axial direction; and an extension portion extending in the axial direction from an inner peripheral end of the pressing portion toward the second cover plate. The disc spring is arranged radially outward with respect to the extended portion.

6. The torque limiter according to claim 1, wherein: The friction generating part comprises: A first friction member is disposed between the first cover plate and the transmission member; and The second friction member is disposed between the pressure plate and the transmission member.

7. The torque limiter according to claim 6, wherein: The transmission member has a flange portion, The flange portion includes an outer peripheral portion and an inner peripheral portion. The outer peripheral portion is provided with the first friction member and the second friction member mounted thereon, and the inner peripheral portion is thicker than the outer peripheral portion.

8. The torque limiter according to claim 7, wherein: The first cover plate has a protrusion that protrudes toward an inner peripheral portion of the flange portion.

9. The torque limiter according to claim 7, wherein: The pressing plate has a protrusion that protrudes toward an inner peripheral portion of the flange portion.

10. The torque limiter according to claim 1, wherein: The transmission member includes a cylindrical portion and a flange portion, wherein the flange portion extends radially outward from the cylindrical portion. The cylindrical portion has a spline hole extending in the axial direction.

11. The torque limiter according to claim 1, wherein: The second cover plate includes a cover body portion and a cylindrical portion, wherein the cover body portion is axially opposed to the disc spring, and the cylindrical portion extends axially from an inner peripheral end portion of the cover body portion. The cylindrical portion has a gear portion in an outer peripheral surface.

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