Fluid Couplings

Abstract

To improve responsiveness of a lock-up piston.SOLUTION: A fluid coupling 100 comprises a cover 2, an impeller 3, a turbine 4, an output hub 6, a lock-up piston 7, and a wall member 82b. The impeller 3 is fixed to the cover 2. The turbine 4 is disposed while facing the impeller 3. The output hub 6 outputs torque from the turbine 4. The lock-up piston 7 is disposed between the cover 2 and the turbine 4. The lock-up piston 7 is disposed so as to be axially slidable on the output hub 6. The lock-up piston 7 is configured to be frictionally engaged to the cover 2. The wall member 82b is attached to the output hub 6. The wall member 82b defines a hydraulic space S in cooperation with the lock-up piston 7.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fluid coupling. [Background technology]

[0002] The fluid coupling has an impeller and a turbine, and transmits torque from the impeller to the turbine via hydraulic oil inside. The impeller is fixed to a cover to which the torque is input. The turbine is disposed opposite the impeller. When the impeller rotates, hydraulic oil flows from the impeller to the turbine, rotating the turbine and outputting torque.

[0003] The fluid coupling also has a lock-up device. When the lock-up device is in an ON state, torque from the cover is mechanically transmitted to the turbine and output to the input shaft of the transmission.

[0004] For example, the torque converter described in Patent Document 1 has a lock-up piston. In a high-speed transmission range, the lock-up piston frictionally engages with the converter cover, thereby improving power transmission efficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-296313 Summary of the Invention [Problem to be solved by the invention]

[0006] In a fluid coupling having a lock-up piston as described above, it is preferable to improve the responsiveness of the lock-up piston from the viewpoint of improving fuel efficiency, etc. Therefore, an object of the present invention is to improve the responsiveness of the lock-up piston. [Means for solving the problem]

[0007] A fluid coupling according to an aspect of the present invention includes a cover, an impeller, a turbine, an output hub, a lock-up piston, and a wall member. The impeller is fixed to the cover. The turbine is disposed opposite the impeller. The output hub outputs torque from the turbine. The lock-up piston is disposed between the cover and the turbine. The lock-up piston is disposed axially slidably on the output hub. The lock-up piston is configured to frictionally engage with the cover. The wall member is attached to the output hub. The wall member cooperates with the lock-up piston to define a hydraulic chamber.

[0008] The above-mentioned fluid coupling has a wall member for defining a hydraulic chamber in cooperation with the lock-up piston. Note that hydraulic oil is supplied to the hydraulic chamber through a supply passage. In this way, the hydraulic chamber is formed by the wall member and the lock-up piston, so that the responsiveness of the lock-up piston can be improved.

[0009] Preferably, the fluid coupling further includes a damper device. The damper device is configured to transmit torque from the lock-up piston to the output hub. The damper device has an input plate, first and second output plates, and an elastic member. The input plate is configured to transmit torque from the lock-up piston. The first and second output plates are arranged to sandwich the input plate in the axial direction. The first and second output plates are attached to the output hub. The elastic member elastically connects the input plate to the first and second output plates. At least one of the first and second output plates constitutes a wall member.

[0010] Preferably, the first output plate is disposed axially between the lock-up piston and the input plate, and the second output plate is disposed axially between the turbine and the input plate, and the second output plate constitutes a wall member.

[0011] Preferably, the first output plate has a first bulging portion that bulges in the axial direction along the shape of the elastic member. The second output plate has a second bulging portion that bulges in the axial direction along the shape of the elastic member. The first bulging portion has an apex portion that is open in the axial direction. That is, the first bulging portion has a window portion at the apex portion. The second bulging portion has an apex portion that is closed in the axial direction. That is, the second bulging portion does not have a window portion at the apex portion.

[0012] Preferably, the first output plate is disposed between the lock-up piston and the input plate in the axial direction, and the second output plate is disposed between the turbine and the input plate in the axial direction. The first output plate constitutes a wall member.

[0013] Preferably, the first output plate has a first bulging portion that bulges in the axial direction along the shape of the elastic member. The second output plate has a second bulging portion that bulges in the axial direction along the shape of the elastic member. The first bulging portion has an apex portion that is closed in the axial direction. That is, the first bulging portion does not have a window portion at the apex portion. The second bulging portion has an apex portion that is open in the axial direction. That is, the second bulging portion has a window portion at the apex portion.

[0014] Preferably, the lock-up piston has a disk portion and a cylindrical portion extending axially from an outer peripheral end of the disk portion, and the wall member extends from the output hub to the cylindrical portion. Effect of the Invention

[0015] According to the present invention, the responsiveness of the lockup piston can be improved. [Brief description of the drawings]

[0016] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4]FIG. 11 is a cross-sectional view of a damper device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [Overall configuration] Fig. 1 is a cross-sectional view of a torque converter 100 (an example of a fluid coupling) according to this embodiment. In the following description, "axial direction" refers to the direction in which a rotation axis O of the torque converter 100 extends. Additionally, "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. Although not shown, an engine is disposed on the left side of Fig. 1, and a transmission is disposed on the right side of Fig. 1.

[0018] 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-up piston 7, and a damper device 8.

[0019] [Cover 2] Torque from the engine is input to the cover 2. The cover 2 has a disk portion 21 and a first cylindrical portion 22. The first cylindrical portion 22 extends in the axial direction from the outer circumferential end of the disk portion 21 toward the impeller 3 side.

[0020] [Impeller 3] The impeller 3 is fixed to the cover 2. The impeller 3 has an impeller shell 31, a plurality of impeller blades 32, and an impeller hub 33. The impeller shell 31 is fixed to the cover 2 by, for example, welding.

[0021] The impeller blades 32 are fixed to the inner surface of the impeller shell 31. The impeller hub 33 is fixed to the inner peripheral end of the impeller shell 31 by welding or the like.

[0022] [Turbine 4] The turbine 4 is disposed opposite the impeller 3. The turbine 4 has a turbine shell 41 and a plurality of turbine blades 42. The turbine blades 42 are fixed to the inner surface of the turbine shell 41 by brazing or the like.

[0023] [Stator 5] The stator 5 is configured to rectify the flow of hydraulic oil returning from the turbine 4 to the impeller 3. The stator 5 is rotatable around a rotation axis O. In detail, the stator 5 is supported on a non-rotatable fixed shaft 101 via a one-way clutch 102. The stator 5 is disposed between the impeller 3 and the turbine 4.

[0024] The stator 5 has a disk-shaped stator carrier 51 and a plurality of stator blades 52 attached to the outer circumferential surface of the stator carrier 51. 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.

[0025] [Output Hub] The output hub 6 is configured to output the torque transmitted from the turbine 4 to the input shaft 105 of the transmission. The turbine 4 is attached to this output hub 6. In detail, the turbine shell 41 is attached to the output hub 6 via rivets or the like. The output hub 6 is formed with a spline hole 611. The input shaft 105 is spline-fitted into this spline hole 611.

[0026] 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 circumferential surface of the boss portion 61. The flange portion 62 is annular and extends in the circumferential direction. The turbine shell 41 is attached to this flange portion 62.

[0027] [Lock-up piston] The lock-up piston 7 is disposed between the cover 2 and the turbine 4 so as to be movable in the axial direction. Specifically, the lock-up piston 7 is disposed so as to be slidable in the axial direction on the output hub 6. More specifically, the lock-up piston 7 is disposed so as to be slidable in the axial direction on the outer circumferential surface of a boss portion 61 of the output hub 6. In addition, the lock-up piston 7 is rotatable relative to the output hub 6.

[0028] As shown in Fig. 2, the lock-up piston 7 is configured to frictionally engage with the cover 2. More specifically, the lock-up piston 7 is configured to frictionally engage with the cover 2 at its outer circumferential end. In the state shown in Fig. 2, the lock-up piston 7 is not frictionally engaged with the cover 2. When the lock-up piston 7 moves to the left from the state shown in Fig. 2, the lock-up piston 7 frictionally engages with the cover 2. The lock-up piston 7 has a disk portion 71, a second cylindrical portion 72 (an example of a cylindrical portion), and a sliding portion 73.

[0029] Friction material 9 is fixed to the outer peripheral end of disc portion 71. Disc portion 71 is configured to press disc portion 21 of cover 2 via friction material 9. In this manner, disc portion 71 presses cover 2 via friction material 9, whereby lock-up piston 7 frictionally engages with cover 2. Note that friction material 9 may be fixed to cover 2 instead of lock-up piston 7. Friction material 9 is annular.

[0030] The second cylindrical portion 72 extends in the axial direction from the outer circumferential end of the disk portion 71. The second cylindrical portion 72 extends in a direction away from the cover 2. The outer circumferential surface of the second cylindrical portion 72 is disposed with a gap between it and the inner circumferential surface of the first cylindrical portion 22 of the cover 2.

[0031] The sliding portion 73 is cylindrical. The sliding portion 73 extends in the axial direction from the inner peripheral end of the disk portion 71. The sliding portion 73 extends in a direction away from the cover 2. The sliding portion 73 is slidably supported on the outer peripheral surface of the output hub 6. A seal member 106 is provided on the outer peripheral surface of the output hub 6, and this seal member 106 seals the gap between the inner peripheral surface of the sliding portion 73 of the lock-up piston 7 and the outer peripheral surface of the output hub 6.

[0032] [Damper device] The damper device 8 is disposed between the lock-up piston 7 and the turbine 4 in the axial direction. The damper device 8 is configured to transmit torque from the lock-up piston 7 to the output hub 6. The damper device 8 elastically connects the lock-up piston 7 and the output hub 6. The damper device 8 has an input plate 81, a first output plate 82a, a second output plate 82b, a plurality of first torsion springs 83 (an example of an elastic member), and a plurality of second torsion springs (not shown).

[0033] [Input Plate] The input plate 81 is configured to transmit torque from the lock-up piston 7. The input plate 81 is formed in a disk shape. The input plate 81 is attached to the lock-up piston 7 at its outer circumferential end. The input plate 81 rotates integrally with the lock-up piston 7. The input plate 81 is movable relative to the lock-up piston 7 in the axial direction.

[0034] More specifically, the input plate 81 has a plurality of teeth on its outer circumferential end portion. The teeth of the input plate 81 engage with a groove portion that is formed in the second cylindrical portion 72 of the lock-up piston 7 and extends in the axial direction.

[0035] The input plate 81 has a first hole portion 811 extending in the circumferential direction. A first torsion spring 83 is housed in this first hole portion 811. The input plate 81 also has a second hole portion (not shown) extending in the circumferential direction. A second torsion spring is housed in this second hole portion. The second hole portion is disposed radially outward of the first hole portion 811.

[0036] [First and second output plates] The first and second output plates 82a, 82b are arranged to sandwich the input plate 81 in the axial direction. That is, the input plate 81 is arranged between the first output plate 82a and the second output plate 82b in the axial direction. The first and second output plates 82a, 82b are rotatable relative to the input plate 81. The first and second output plates 82a, 82b rotate integrally with each other.

[0037] The first output plate 82a is disposed axially between the lock-up piston 7 and the input plate 81. The second output plate 82b is disposed axially between the turbine 4 and the input plate 81. That is, the lock-up piston 7, the first output plate 82a, the input plate 81, and the second output plate 82b are disposed in this order in the axial direction.

[0038] The first and second output plates 82a, 82b are attached to the output hub 6. For example, the first and second output plates 82a, 82b are fixed at their inner circumferential ends to the flange portion 62 of the output hub 6 by rivets or the like.

[0039] The first output plate 82a has a plurality of first bulging portions 821a. The first bulging portions 821a face the first torsion springs 83 in the axial direction. The first bulging portions 821a extend in the circumferential direction.

[0040] The first bulging portion 821a bulges in the axial direction in accordance with the shape of the first torsion spring 83. In detail, the first bulging portion 821a bulges toward the lock-up piston 7. The apex of the first bulging portion 821a opens in the axial direction. That is, the first bulging portion 821a has a window portion 822a.

[0041] The first output plate 82a also has a plurality of third bulging portions 823a. The third bulging portions 823a are disposed radially outward of the first bulging portions 821a. The third bulging portions 823a face the second torsion springs. The third bulging portions 823a extend in the circumferential direction.

[0042] The third bulging portion 823a bulges in the axial direction along the shape of the second torsion spring. In detail, the third bulging portion 823a bulges toward the lock-up piston 7. That is, the third bulging portion 823a bulges in the same direction as the first bulging portion 821a. The third bulging portion 823a bulges less than the first bulging portion 821a. The apex of the third bulging portion 823a opens in the axial direction. That is, the third bulging portion 823a has a window portion 824a.

[0043] The second output plate 82b cooperates with the lock-up piston 7 to define a hydraulic chamber S. That is, the second output plate 82b constitutes a wall member.

[0044] 2 and 3, the second output plate 82b has a plurality of second bulging portions 821b. The second bulging portions 821b face the first torsion springs 83 in the axial direction. The second bulging portions 821b extend in the circumferential direction. The radial positions of the second bulging portions 821b are substantially the same as those of the first bulging portions 821a.

[0045] The second bulging portion 821b bulges in the axial direction in accordance with the shape of the first torsion spring 83. In detail, the second bulging portion 821b bulges toward the turbine 4. The apex of the second bulging portion 821b is closed in the axial direction. That is, the second bulging portion 821b is not open in the axial direction and does not have a window portion.

[0046] The second output plate 82b has a plurality of fourth bulging portions 823b. The fourth bulging portions 823b are disposed radially outward from the second bulging portions 821b. The fourth bulging portions 823b face the second torsion springs. The fourth bulging portions 823b extend in the circumferential direction.

[0047] The fourth bulging portion 823b bulges in the axial direction along the shape of the second torsion spring. In detail, the fourth bulging portion 823b bulges toward the turbine 4. That is, the fourth bulging portion 823b bulges in the same direction as the second bulging portion 821b. The fourth bulging portion 823b bulges less than the second bulging portion 821b. The apex of the fourth bulging portion 823b is closed in the axial direction. That is, the fourth bulging portion 823b is not open in the axial direction and does not have a window portion.

[0048] In this way, the second output plate 82b does not have a window portion that opens in the axial direction. Therefore, the second output plate 82b cooperates with the lock-up piston 7 to define the hydraulic chamber S. In other words, the second output plate 82b constitutes a wall member. The second output plate 82b extends from the output hub 6 to the second cylindrical portion 72 of the lock-up piston 7. The outer peripheral surface of the second output plate 82b may or may not be in contact with the inner peripheral surface of the second cylindrical portion 72.

[0049] When the outer peripheral surface of the second output plate 82b and the inner peripheral surface of the second cylindrical portion 72 are not in contact, the gap between the outer peripheral surface of the second output plate 82b and the inner peripheral surface of the second cylindrical portion 72 can be approximately 1.5 mm or less, and preferably approximately 0.5 mm or less.

[0050] Furthermore, the torque converter 100 has a plurality of supply passages 11. The supply passages 11 are configured to supply hydraulic oil into a hydraulic chamber S formed by the second output plate 82b and the lock-up piston 7.

[0051] The supply passages 11 are through holes that penetrate the turbine shell 41, the flange portion 62, the first output plate 82a, and the second output plate 82b. The supply passages 11 are arranged at intervals from one another in the circumferential direction.

[0052] [Torsion spring] 2, the first torsion spring 83 elastically connects the input plate 81 to the first and second output plates 82a, 82b. The first torsion spring 83 transmits torque from the input plate 81 to the first and second output plates 82a, 82b.

[0053] The second torsion spring elastically connects the input plate 81 to the first and second output plates 82a, 82b. The second torsion spring, together with the first torsion spring 83, transmits torque from the input plate 81 to the first and second output plates 82a, 82b. Note that only the first torsion spring 83 operates until the torsion angle between the input plate 81 and the first and second output plates 82a, 82b exceeds a predetermined value, and when the torsion angle exceeds the predetermined value, the second torsion spring operates together with the first torsion spring 83.

[0054] [Operation] Next, the operation of the torque converter 100 configured as described above will be described. In a torque converter operating range in which torque is transmitted from the impeller 3 to the turbine 4 via hydraulic oil, the lock-up piston 7 moves axially away from the cover 2 and is not in frictional engagement with the cover 2. In other words, the lock-up piston 7 does not transmit torque.

[0055] Next, when the torque converter reaches a predetermined condition, hydraulic oil is supplied to the hydraulic chamber S via the supply path 11. This causes the lock-up piston 7 to move toward the cover 2, and the lock-up piston 7 and the cover 2 are frictionally engaged. As a result, the torque from the cover 2 is transmitted to the output hub 6 via the lock-up piston 7 and the damper device 8.

[0056] [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.

[0057] For example, in the above embodiment, the second output plate 82b constitutes the wall member, but the configuration of the torque converter 100 is not limited to this. In particular, the first output plate 82a may constitute the wall member.

[0058] In this case, as shown in Fig. 4, the apex of the first bulging portion 821a of the first output plate 82a is closed in the axial direction. That is, the first bulging portion 821a is not open in the axial direction and does not have a window portion. On the other hand, the apex of the second bulging portion 821b of the second output plate 82b is open in the axial direction. That is, the second bulging portion 821b has a window portion 822b.

[0059] Also, the apex of the third bulging portion 823a of the first output plate 82a is closed in the axial direction. That is, the third bulging portion 823a is not open in the axial direction and does not have a window portion. On the other hand, the apex of the fourth bulging portion 823b of the second output plate 82b is open in the axial direction. That is, the fourth bulging portion 823b has a window portion 824b.

[0060] Both the first output plate 82a and the second output plate 82b may form wall members. That is, all of the first to fourth bulging portions 821a, 821b, 823a, and 823b may be closed in the axial direction. [Explanation of symbols]

[0061] 2: Cover 3: Impeller 4: Turbine 6: Output hub 7: Lockup piston 71: Disc section 72: Second cylindrical section 8: Damper device 81: Input plate 82a: 1st output plate 821a: 1st bulge 822a: Window section 82b: 2nd output plate 821b:Second bulge 822b: Window section 83: First torsion spring 100: Torque converter

Claims

1. Cover and an impeller fixed to the cover; A turbine disposed opposite the impeller; an output hub configured to output torque from the turbine; a lock-up piston disposed between the cover and the turbine, the lock-up piston being axially slidably disposed on the output hub and configured to frictionally engage the cover; a wall member attached to the output hub and cooperating with the lock-up piston to define a hydraulic chamber; a damper device configured to transmit torque from the lock-up piston to the output hub; Equipped with The damper device is an input plate configured to transmit torque from the lock-up piston; first and second output plates disposed on either side of the input plate in the axial direction and attached to the output hub; an elastic member that elastically connects the input plate to the first and second output plates; having At least one of the first and second output plates constitutes the wall member. Fluid coupling.

2. the first output plate is disposed between the lock-up piston and the input plate in the axial direction, the second output plate is axially disposed between the turbine and the input plate; The second output plate constitutes the wall member. The fluid coupling according to claim 1.

3. the first output plate has a first bulging portion that bulges in the axial direction along the shape of the elastic member, the second output plate has a second bulging portion that bulges in the axial direction along the shape of the elastic member, The first bulge portion has an apex portion that is open in the axial direction, The second bulge portion has a top portion that is closed in the axial direction. The fluid coupling according to claim 2.

4. the first output plate is disposed between the lock-up piston and the input plate in the axial direction, the second output plate is axially disposed between the turbine and the input plate; The first output plate constitutes the wall member. The fluid coupling according to claim 1.

5. the first output plate has a first bulging portion that bulges in the axial direction along the shape of the elastic member, the second output plate has a second bulging portion that bulges in the axial direction along the shape of the elastic member, The first bulge portion has a top portion that is closed in the axial direction, The second bulge portion has an apex portion that is open in the axial direction. The fluid coupling according to claim 4.

6. The lock-up piston has a disk portion and a cylindrical portion extending in an axial direction from an outer circumferential end portion of the disk portion, The wall member extends from the output hub to the cylindrical portion. A fluid coupling according to any one of claims 1 to 5.

Images