Hydraulic coupling

Abstract

The utility model relates to a fluid coupling which inhibits cracks in a concave corner part of a cover. The cover has a recessed corner portion, a first rounded corner surface, and a second rounded corner surface. The concave corner part is composed of a circular plate part and a cylindrical part. The recessed corner portion extends in a circumferential direction. The first rounded surface extends in the circumferential direction at the recessed corner portion. The second rounded surface is disposed radially outward of the first rounded surface in the recessed portion. The second rounded surface extends in a circumferential direction along the first rounded surface.

Description

Technical Field

[0001] The utility model relates to a hydraulic coupling. Background Art

[0002] A fluid coupling such as a torque converter has a cover, an impeller, and a turbine (for example, see Patent Document 1). The cover has a disc portion and a cylindrical portion. The cylindrical portion extends axially from the outer peripheral end of the disc portion. The torque converter is filled with working oil for transmitting torque between the impeller and the turbine.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-016754 Utility Model Content

[0004] When the torque converter rotates, the internal pressure caused by the hydraulic oil is concentrated on the concave corner portion formed at the intersection of the disc portion and the cylindrical portion, and there is a possibility that cracks will occur in the concave corner portion.

[0005] The technical problem of the present invention is to suppress the generation of cracks in the concave corner portion of the cover.

[0006] The hydraulic coupling involved in the first embodiment includes a cover, an impeller and a turbine. The cover has a circular plate portion and a cylindrical portion. The cylindrical portion extends axially from the outer peripheral end of the circular plate portion. The impeller is fixed to the cylindrical portion. The turbine and the impeller are arranged opposite to each other. The cover has a concave corner portion, a first rounded surface and a second rounded surface. The concave corner portion is composed of a circular plate portion and a cylindrical portion. The concave corner portion extends in the circumferential direction. The first rounded surface extends in the circumferential direction at the concave corner portion. The second rounded surface is arranged radially outward relative to the first rounded surface at the concave corner portion. The second rounded surface extends in the circumferential direction along the first rounded surface.

[0007] According to this configuration, since the concave corner portion has two rounded surfaces, the first rounded surface and the second rounded surface, the internal pressure acting on the concave corner portion can be dispersed to the first rounded surface and the second rounded surface, respectively. As a result, the occurrence of cracks in the concave corner portion of the cover can be suppressed.

[0008] According to the fluid coupling according to the first aspect, a fluid coupling according to a second aspect is configured as follows: The second fillet surface is arranged radially outward with respect to the inner peripheral surface of the cylindrical portion.

[0009] A third aspect of the fluid coupling according to the first or second aspect is a fluid coupling having the following configuration: In a cross-sectional plane including the rotation axis, the first fillet surface and the second fillet surface are connected by a common tangent line between the first fillet surface and the second fillet surface.

[0010] A fourth aspect of the fluid coupling according to any one of the first to third aspects has the following configuration: the cover has a truncated conical surface connecting the first rounded surface and the second rounded surface.

[0011] According to a fifth aspect of the fluid coupling according to any one of the first to fourth aspects, the fluid coupling has the following configuration: The curvature radius of the first fillet surface is substantially the same as the curvature radius of the second fillet surface.

[0012] According to the fluid coupling of any one of the first to fifth aspects, the fluid coupling of the sixth aspect further comprises a lock piston. The lock piston is arranged between the cover and the turbine to be movable in the axial direction. The first fillet surface and the second fillet surface are opposed to the lock piston.

[0013] According to the present invention, it is possible to suppress the occurrence of cracks in the concave corner portion of the cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a cross-sectional view of the torque converter.

[0015] Figure 2 yes Figure 1 Magnified image of .

[0016] Description of Reference Numerals

[0017] 2: cover; 21: first circular plate portion; 22: first cylindrical portion; 23: concave corner portion; 24: first rounded corner surface; 25: second rounded corner surface; 26: conical cone surface; 3: impeller; 4: turbine; 7: locking piston. DETAILED DESCRIPTION

[0018] Overall composition

[0019] Figure 1 : is a cross-sectional view of a torque converter 100 (an example of a fluid coupling) according to the present embodiment. Figure 1 1 is a cross-sectional view showing a cut surface of the torque converter 100 including the rotation axis O. In the following description, "axial direction" refers to the direction in which the rotation axis O of the torque converter 100 extends. In addition, "radial direction" refers to the radial direction of a circle centered on the rotation axis O, and "circumferential direction" refers to the circumferential direction of a circle centered on the rotation axis O. It should be noted that, although not shown in the figure, Figure 1 The engine is located on the left side of the Figure 1 The transmission is located on the right side of the vehicle.

[0020] The torque converter 100 is rotatable about a rotation axis O. The torque converter 100 includes a cover 2, an impeller 3, a turbine 4, a stator 5, an output hub 6, a lock piston 7, and a damper device 8. The housing of the torque converter 100 is constituted by the cover 2 and the impeller 3. The torque converter 100 is filled with hydraulic oil.

[0021] build

[0022] The cover 2 is input with torque from the engine. The cover 2 has a first disc portion 21 and a first cylindrical portion 22. The first cylindrical portion 22 extends axially from the outer peripheral end of the first disc portion 21. Specifically, the first cylindrical portion 22 extends axially from the first disc portion 21 toward the impeller 3. That is, the first cylindrical portion 22 extends along the first side in the axial direction.

[0023] Figure 2 yes Figure 1 It should be noted that Figure 2 In FIG. 2 , only the cover 2 is shown. Figure 2 As shown, the cover 2 has a concave corner portion 23, a first rounded corner surface 24 and a second rounded corner surface 25. The concave corner portion 23 is composed of the first disc portion 21 and the first cylindrical portion 22. That is, the concave corner portion 23 is arranged at the intersection area of ​​the first disc portion 21 and the first cylindrical portion 22. The concave corner portion 23 is annular and extends in the circumferential direction.

[0024] The first fillet surface 24 is disposed on the concave corner portion 23. The first fillet surface 24 is annular and extends in the circumferential direction. Figure 2 The first rounded surface 24 faces radially inward and axially toward the first side.

[0025] The second fillet surface 25 is disposed at the concave corner portion 23. The second fillet surface 25 is annular and extends in the circumferential direction. Figure 2 The second rounded surface 25 faces radially inward and axially toward the first side.

[0026] The second rounded surface 25 is arranged radially outwardly with respect to the first rounded surface 24. The second rounded surface 25 extends along the first rounded surface 24. In addition, the second rounded surface 25 is arranged at a distance from the first rounded surface 24.

[0027] The second fillet surface 25 is arranged radially outward relative to the inner peripheral surface 221 of the first cylindrical portion 22 . It should be noted that a portion of the second fillet surface 25 may be arranged radially inward relative to the inner peripheral surface 221 of the first cylindrical portion 22 .

[0028] The cover 2 has a truncated cone surface 26 between the first rounded surface 24 and the second rounded surface 25. In the cross-sectional plane including the rotation axis O, that is, in the cross-sectional plane including the rotation axis O, Figure 2 In the cross-sectional plane shown, the first rounded surface 24 and the second rounded surface 25 are connected by a common tangent line between the first rounded surface 24 and the second rounded surface 25. The frustum surface 26 constitutes a common tangent line between the first rounded surface 24 and the second rounded surface 25 in the cross-sectional plane. The frustum surface 26 is a side surface of a frustum of a cone. The diameter of the frustum surface 26 gradually increases toward the first axial side.

[0029] The first rounded surface 24 has substantially the same curvature radius as the second rounded surface 25. For example, the difference between the first rounded surface 24 and the second rounded surface 25 is about 1 mm or less, preferably 0.5 mm or less.

[0030] The arc length of the first rounded surface 24 in the cross section is substantially the same as the arc length of the second rounded surface 25. For example, the difference between the arc lengths of the first rounded surface 24 and the second rounded surface 25 is about 1 mm or less, preferably 0.5 mm or less.

[0031] The first rounded surface 24 and the second rounded surface 25 face the lockup piston 7. Specifically, the first rounded surface 24 and the second rounded surface 25 face a convex corner portion 73 of the lockup piston 7, which will be described later.

[0032] impeller

[0033] like Figure 1 As shown, the impeller 3 is fixed to the cover 2. Specifically, the impeller 3 is fixed to the first cylindrical portion 22 of the cover 2. The impeller 3 includes an impeller casing 31, a plurality of impeller blades 32, and an impeller hub 33. The impeller casing 31 is fixed to the cover 2 by, for example, welding.

[0034] The impeller blades 32 are fixed to the inner side surface of the impeller housing 31. The impeller hub 33 is fixed to the inner peripheral end portion of the impeller housing 31 by welding or the like.

[0035] turbine

[0036] The turbine 4 is disposed to face the impeller 3. The turbine 4 includes a turbine housing 41 and a plurality of turbine blades 42. The turbine blades 42 are fixed to the inner side surface of the turbine housing 41 by brazing or the like.

[0037] stator

[0038] The stator 5 is configured to rectify the hydraulic oil returned from the turbine 4 to the impeller 3. The stator 5 is rotatable about the rotation axis O. Specifically, the stator 5 is supported by a non-rotatable fixed shaft (not shown) via a one-way clutch 102. The stator 5 is disposed between the impeller 3 and the turbine 4.

[0039] The stator 5 has a disc-shaped stator bracket 51 and a plurality of stator blades 52 mounted on the outer peripheral surface thereof. It should be noted that a first thrust bearing 103 is disposed between the stator 5 and the impeller 3 , and a second thrust bearing 104 is disposed between the stator 5 and the output hub 6 .

[0040] Output hub

[0041] The output hub 6 is configured to output the torque transmitted from the turbine 4 to the input shaft (not shown) of the transmission. The turbine 4 is mounted on the output hub 6. Specifically, the turbine housing 41 is mounted on the output hub 6 via rivets or the like. The output hub 6 is formed with a spline hole 611. The input shaft is spline-fitted with the spline hole 611.

[0042] The output hub 6 has a boss portion 61 and a flange portion 62. The boss portion 61 is cylindrical and extends in the axial direction. The boss portion 61 has a spline hole 611. The flange portion 62 extends radially outward from the outer peripheral surface of the boss portion 61. The flange portion 62 is annular and extends in the circumferential direction. The turbine housing 41 is mounted on the flange portion 62.

[0043] Locking piston

[0044] The locking piston 7 is configured to be movable in the axial direction between the cover 2 and the turbine 4. Specifically, the locking piston 7 is configured to be slidable in the axial direction on the output hub 6. More specifically, the locking piston 7 is configured to be slidable in the axial direction on the outer peripheral surface of the boss portion 61 of the output hub 6. In addition, the locking piston 7 is rotatable relative to the output hub 6.

[0045] The locking piston 7 is configured to frictionally engage with the cover 2. Specifically, the locking piston 7 is configured to frictionally engage with the cover 2 at the outer peripheral end. The locking piston 7 moves to the left, so that the locking piston 7 and the cover 2 are frictionally engaged. The locking piston 7 has a second disc portion 71, a second cylindrical portion 72, and a convex corner portion 73.

[0046] The friction material 9 is fixed to the outer peripheral end of the second disc portion 71. The second disc portion 71 is configured to press the first disc portion 21 of the cover 2 via the friction material 9. In this way, the second disc portion 71 presses the cover 2 via the friction material 9, so that the locking piston 7 and the cover 2 are frictionally engaged. It should be noted that the friction material 9 can also be fixed to the cover 2 instead of the locking piston 7. The friction material 9 is annular.

[0047] The second cylindrical portion 72 extends axially from the outer peripheral end of the second circular plate portion 71. The second cylindrical portion 72 extends in a direction away from the cover 2. That is, the second cylindrical portion 72 extends along the first side in the axial direction. The outer peripheral surface of the second cylindrical portion 72 is arranged at a distance from the inner peripheral surface of the first cylindrical portion 22 of the cover 2.

[0048] The convex corner portion 73 is composed of the second disc portion 71 and the second cylindrical portion 72. That is, the convex corner portion 73 is arranged at the intersection area of ​​the second disc portion 71 and the second cylindrical portion 72. The convex corner portion 73 is annular and extends in the circumferential direction. The convex corner portion 73 is opposite to the concave corner portion 23. The convex corner portion 73 is C-chamfered.

[0049] Damping device

[0050] The damping device 8 is arranged between the locking piston 7 and the turbine 4 in the axial direction. The damping device 8 is connected to the locking piston 7 on the input side. In addition, the damping device 8 is connected to the output hub 6 on the output side. The damping device 8 is configured to transmit torque from the locking piston 7 to the output hub 6. The damping device 8 elastically connects the locking piston 7 and the output hub 6. In detail, the damping device 8 has a coil spring 81, and the locking piston 7 is connected to the output hub 6 via the coil spring 81.

[0051] action

[0052] Next, the operation of the torque converter 100 constructed as above will be described. In the torque converter operation region where torque is transmitted from the impeller 3 to the turbine 4 via the hydraulic oil, the lockup piston 7 moves axially away from the cover 2 and does not frictionally engage with the cover 2. That is, the lockup piston 7 does not transmit torque.

[0053] Next, when the rotation speed of the torque converter 100 reaches a predetermined value or more, the lockup piston 7 moves toward the cover 2 and frictionally engages with the cover 2. As a result, the torque from the cover 2 is transmitted to the output hub 6 via the lockup piston 7 and the damper device 8.

[0054] Modifications

[0055] As mentioned above, although embodiment of this invention was described, this invention is not limited to these, Unless it deviates from the summary of this invention, various changes can be made.

[0056] (a) In the above embodiment, the first rounded surface 24 has a substantially same curvature radius as the second rounded surface 25, but may be different from the curvature radius of the second rounded surface 25. In addition, the arc length of the first rounded surface 24 may be different from the arc length of the second rounded surface 25.

[0057] (b) In the above embodiment, the torque converter 100 is exemplified as the fluid coupling, but the fluid coupling may not be a torque converter. That is, the fluid coupling may not have the stator 5. In addition, the fluid coupling may not have the lockup piston 7 or the damper device 8.

[0058] (c) The first rounded surface 24 and the second rounded surface 25 may be directly connected. That is, the cover 2 may not have the truncated cone surface 26.

Claims

1. A hydraulic coupling, characterized in that: have: A cover having a circular plate portion and a cylindrical portion extending axially from an outer peripheral end portion of the circular plate portion; an impeller fixed to the cylindrical portion; and a turbine, arranged opposite to the impeller, The cover has: A concave corner portion, formed by the circular plate portion and the cylindrical portion, extending in the circumferential direction; A first fillet surface extending circumferentially at the concave corner portion; as well as The second fillet surface is arranged radially outwardly relative to the first fillet surface at the concave corner portion and extends in the circumferential direction along the first fillet surface.

2. The hydraulic coupling according to claim 1, characterized in that: The second fillet surface is arranged radially outward with respect to the inner peripheral surface of the cylindrical portion.

3. The hydraulic coupling according to claim 1, characterized in that: In a cross-sectional plane including the rotation axis, the first rounded surface and the second rounded surface are connected by a common tangent line between the first rounded surface and the second rounded surface.

4. The hydraulic coupling according to claim 1, characterized in that: The cover has a truncated cone surface connecting the first rounded surface and the second rounded surface.

5. The hydraulic coupling according to claim 1, characterized in that: The curvature radius of the first fillet surface is the same as the curvature radius of the second fillet surface.

6. The hydraulic coupling according to claim 1, characterized in that: The fluid coupling further includes a lock piston disposed between the cover and the turbine so as to be movable in the axial direction. The first rounded surface and the second rounded surface are opposite to the locking piston.

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