JP3742237B2 - Lubrication structure of friction engagement device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lubrication structure for a friction engagement device in an automatic transmission for a vehicle.
[0002]
[Prior art]
As a friction engagement device in an automatic transmission, for example, a clutch is configured such that a plurality of friction plates that engage with each other between two rotating members are alternately stacked and frictionally engaged by pressing these friction plates with a piston to rotate both. The members are integrated and fastened to transmit the rotation. Therefore, when the rotation is not transmitted, the above-mentioned pressure is released to release the frictional engagement, but even if the pressure is released, contact between the friction plates engaged between the two rotating members is inevitable. It is necessary to reduce the frictional force and prevent wear, and it is also necessary to prevent wear and heat generation due to sliding friction during the fastening and releasing operations.
[0003]
Therefore, in general, oil is supplied to the friction plate portion of the clutch through various paths from the oil path formed in the central portion of the rotating shaft to lubricate the friction plates.
FIG. 4 shows one disclosed in Japanese Utility Model Publication No. 4-90737 as an example of a conventional clutch lubrication structure. Here, the drum 90 is spline-coupled to the rotating shaft 80, and the spline 92 is formed on the inner peripheral surface of the outer peripheral drum portion 91 of the drum 90. A hub 100 is rotatably provided on the rotary shaft 80 via a bearing 84, and a spline 101 is formed on the outer peripheral surface of the hub 100. The hub 100 is connected to another rotating member (not shown).
[0004]
The spline 92 of the drum 90 and the spline 101 of the hub 100 are arranged to face each other, and a plurality of friction plates 108 and 109 that mesh with one spline are alternately arranged between the two. One of these friction plates is regulated by a snap ring 107 engaged with a spline 92 of the drum 90, and is pressed by a piston 95 from the other side.
[0005]
A cylinder 99 is formed between the inner peripheral surface excluding the spline 92 portion of the drum 90 and the rotary shaft 80, and the piston 95 is slidably accommodated in the cylinder 99. The cylinder 99 is supplied with working oil from a first oil passage 81 provided on the rotary shaft 80. When the working oil is supplied to the cylinder, the piston 95 moves against the return spring 86 disposed between the piston 95 and the hub 100 and presses the friction plates 108 and 109.
The drum 90, the hub 100, and the friction plates 108 and 109 constitute a clutch.
[0006]
A second oil passage 82 is further formed in the rotary shaft 80, and the second oil passage opens in a ring groove 83 formed at a position corresponding to the spline 101 of the hub 100 in the axial direction.
The piston 95 includes an extension cylinder portion 96 extending along the rotation shaft 80. The extension cylinder portion 96 is provided with an oil hole 97 that can communicate with the ring groove 83 according to the movement of the piston stroke and can be shut off. Seal rings 98 and 98 are provided on both sides in the axial direction across the hole 97.
[0007]
The hub 100 is provided with a plurality of lubricating holes 102 corresponding to the positions of the friction plates 108 and 109, and the drum 90 is provided with a discharge hole 94 in a discharge groove 93 formed following the end of the spline 92. ing.
[0008]
Thereby, when the oil hole 97 of the extension cylinder part 96 communicates with the ring groove 83 by the movement of the piston 95, the second oil path 82 of the rotating shaft 80 passes through the oil hole 97 and enters the inner space of the spline part of the hub 100. Oil is supplied and this oil flows between the friction plates 108 and 109 from the plurality of lubricating holes 102 of the hub to lubricate them.
The oil lubricated between the friction plates flows into the discharge groove 93 and is discharged from the discharge hole 94 to the outside of the drum 90. Further, when the communication between the oil hole 97 of the extension cylinder portion 96 and the ring groove 83 is blocked by the movement of the piston 95, the flow of oil to the inner space is stopped, and as a result, the oil is also supplied to the friction plate. Stop. Thus, oil is supplied in a controlled manner to the friction plate of the clutch.
[0009]
[Problems to be solved by the invention]
However, in the above-described conventional lubrication structure, in order to supply oil to the clutch in a controlled manner, the rotary shaft 80 is provided with a ring groove 83, and the piston 95 is moved so as to communicate with and shut off the ring groove 83. Therefore, the seal rings 98 and 98 on both sides sandwiching the oil hole 97 must have an allowance for the interval so that they do not overlap the ring groove 83 even when the piston moves. For this reason, the piston is provided with a long extension tube portion 96, and there is a problem that the size of the transmission as a whole increases in the axial direction.
[0010]
Accordingly, in view of the above-described conventional problems, the present invention provides a lubrication structure for a friction engagement device capable of supplying lubricating oil to a friction plate in a timely manner without increasing the axial size of the transmission. With the goal.
[0011]
[Means for Solving the Problems]
Therefore, according to the present invention, a friction plate that is spline-fitted on the inner periphery of the drum and a friction plate that is spline-fitted on the outer periphery of the hub are alternately arranged, and a piston capable of pressing these friction plates is provided in the drum. Then, the friction plates are pressed against each other by the advance of the piston by the hydraulic pressure supply so as to rotate the drum and the hub integrally, and the pressure between the friction plates is released by the retreat of the piston by the hydraulic pressure release. A lubricating structure for supplying lubricating oil between the friction plates of a friction engagement device in a released state that allows relative rotation with the hub, from an axial oil passage inside the rotating shaft of the drum to the rotating shaft The lubricating oil released to the outside of the hub is guided to the space on the inner peripheral side of the spline portion of the hub, and the lubricating oil is supplied between the friction plates through a lubricating hole extending radially in the spline portion and penetrating through the inside and outside of the hub. In the lubricating structure of the frictional engagement device, the first oil passage partitioned by the friction plate side surface of the piston and the vertical wall portion extending in the radial direction of the hub, and the inner circumferential space of the spline portion of the hub. A hole penetrated through the wall of the hub so as to guide oil from one oil passage, and the vertical wall within the position of the hole penetrated in the radial direction on the vertical wall of the hub of the piston And a protruding wall portion protruding toward the
When the piston advances, the protruding wall portion approaches the vertical wall portion of the hub, and the amount of lubricating oil flowing out from the through-hole is made smaller than when the piston is retracted.
[0012]
At the time of fastening, the supply of lubricating oil to the friction plate portion is reduced and reduced, while at the time of release requiring the most lubrication, the lubricating oil is reliably supplied to the friction plate portion.
Further, since the piston does not have an oil hole that communicates with or shuts off the oil supply ring groove of the rotary shaft as in the prior art, the axial length of the sliding surface of the piston can be short.
[0013]
In addition, since the lubricating oil is supplied from the inner diameter direction to the friction plate, uniform and sufficient lubrication is achieved, and the vertical wall portion is close to the piston side, so the adjacent member is placed in the inner space of the outer peripheral cylindrical portion of the hub The axial size of the entire transmission can be reduced.
[0014]
Furthermore, when a plurality of holes that penetrate the wall of the hub are provided on the side wall of the vertical wall facing the piston, the guide can be provided along the outer edge of the plurality of holes so that the oil can be efficiently used. Guided to a plurality of holes.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to examples.
FIG. 1 shows an embodiment in which the present invention is applied to a clutch provided in a sub-transmission in an automatic transmission comprising a main transmission configured on the same axis as the torque converter and a sub-transmission arranged in parallel therewith. It is sectional drawing shown.
An output shaft 15 including an output gear 16 is supported by a transmission case 10 of the automatic transmission via a bearing 30. The outer end 17 of the output shaft 15 protrudes and is inserted into the support hole 12 of the transmission case, and a support hole 18 is provided at the center of the inner end to support the coaxial input shaft 25 via a bearing 31. Yes.
[0016]
A shoulder 19 having a diameter slightly smaller than the root diameter is formed on the output gear 16 formed on the inner side of the bearing position 30. A cylindrical portion 20 extending in the axial direction having a smaller diameter is formed at the end of the shoulder portion 19.
A parking gear 33 is fitted in the shoulder 19. The parking gear 33 has an annular shape obtained by press-molding a plate material. The parking gear 33 is provided with teeth 35 on the outer periphery of the disk portion 34 extending in the radial direction. The inner peripheral edge of the disk portion 34 is fitted into the shoulder portion 19 and is welded at the fitting portion. .
[0017]
A clutch 40 is provided on the inner side of the parking gear 33. The clutch 40 includes a clutch drum 41, a hub 50, friction plates 45 and 46, a piston 47, and the like.
The clutch drum 41 is larger in diameter than the parking gear 33 and has a spline portion 42 having a spline 42A formed on the inner peripheral surface thereof, an outer peripheral wall portion 43 having substantially the same diameter as the parking gear 33, and radially outward from the outer peripheral wall portion 43. The bottom wall 44 extends.
[0018]
The inner peripheral edge of the bottom wall 44 of the clutch drum is offset toward the parking gear 33 and is positioned in a recess 36 formed in the disk 34 of the parking gear, and the inner peripheral edge is welded to the disk 34. .
A plurality of oil discharge holes 78 are formed in the spline portion 42.
[0019]
Inside the clutch drum 41, a hub 50 having a spline 52 opposed to the spline 42A in the outer peripheral cylinder portion 51 is disposed, and a plurality of friction plates 45 and 46 that respectively engage with the spline 42A and the spline 52 are alternately arranged in the axial direction. A sheet is provided.
The hub 50 has an inner peripheral wall portion 53 splined to the input shaft 25 and a vertical wall portion 54 extending radially from the inner peripheral wall portion, and the outer peripheral cylindrical portion 51 is connected to the outer periphery of the vertical wall portion 54. In other words, the vertical wall portion 54 extends from the outer peripheral cylindrical portion 51 in the inner diameter direction.
A plurality of lubricating holes 77 are formed in the outer peripheral cylinder portion 51 within the arrangement range of the friction plates 45 and 46.
[0020]
A thrust bearing 60 is provided between the vertical wall portion 54 and the end portion of the cylindrical portion 20 of the output gear 15.
A ring-shaped cylinder 48 is formed in the outer peripheral wall portion 43 of the clutch drum 41, and the inner peripheral surface 49 of the outer peripheral wall portion 43 and the outer peripheral surface 21 of the cylindrical portion 20 of the output shaft 15 become sliding surfaces of the piston 47. ing.
[0021]
The piston 47 includes seal rings 66 and 67 on the outer peripheral surface and inner peripheral surface thereof, and in particular, the inner peripheral surface has a short width (axial direction) dimension sufficient to secure a ring groove for holding the seal ring 67. . The piston 47 includes a pressing portion 58 that extends toward the friction plates 45 and 46, and a protruding wall portion 62 that extends toward the vertical wall portion 54 of the hub 50. The protruding length of the protruding wall portion 62 is set so that when the piston 47 presses the friction plates 45 and 46, the tip of the protruding wall portion 62 approaches the vertical wall portion 54 but does not come into contact therewith.
[0022]
A return spring 23 is provided on the inner side of the projecting wall portion 62 of the piston between the tip 20 of the cylindrical portion 20 and the spring holder 22 positioned by the snap ring 24, and the pressing portion 58 is connected to the friction plate 45, It is biased in a direction away from 46.
[0023]
The vertical wall portion 54 of the hub is provided with a plurality of holes 76 on the radially outer side than the protruding wall portion 62 of the piston. Although not specifically illustrated, these holes 76 are arranged at substantially equal intervals in the circumferential direction.
Further, a guide 68 is provided in the vicinity of the outer peripheral cylindrical portion 51 along the outer edge of the plurality of holes 76 on the side wall of the vertical wall portion 54 facing the piston 47. The guide 68 extends toward the piston 47 and overlaps the outside of the protruding wall portion 62 with a small gap in the axial direction.
[0024]
The output shaft 15 is formed with an axial oil passage 70 that opens to the outer end of the output shaft 15 and an oil passage 71 that obliquely crosses the portion of the output gear 16 in the drawing. The oil passage 13 and the cylinder 48 of the transmission case 10 are connected to each other. The piston 47 presses the friction plates 45 and 46 by connecting and supplying pressure oil to the cylinder 48.
[0025]
The output shaft 15 is further formed with an axial oil passage 72 that opens into the support hole 18 at the inner end thereof and communicates with the oil passage 14 of the transmission case 10. The input shaft 25 is formed with an axial oil passage 73 that opens into the support hole 18 of the output shaft 15, and an oil hole 74 that connects the inner space of the cylindrical portion 20 of the output shaft and the axial oil passage 73. Is provided. As a result, the bearing 31 has oil (lubricating oil) guided from the axial oil passage 72 through a gap between the shaft end of the input shaft 25 and the bottom wall of the support hole 18, and oil holes from the axial oil passages 72 and 73. Lubricated by oil guided through 74.
[0026]
The oil guided from the oil hole 74 to the inner space of the cylindrical portion 20 of the output shaft lubricates the thrust bearing 60 between the end portion of the cylindrical portion 20 and the vertical wall portion 54 of the hub, and the protruding wall of the piston 47. It flows to the space provided with the return spring 23 inside the portion 62.
This space is partitioned by the piston 47 and the vertical wall portion 54 of the hub, and constitutes the first oil passage in the invention.
[0027]
The oil that has flowed into this space lubricates the friction plates 45 and 46 of the clutch 40 in a controlled manner according to the operation of the piston 47.
FIG. 2 is an enlarged view of the clutch portion showing the flow of oil in the released state of the clutch 40, and FIG. 3 is an enlarged view showing the engaged state of the clutch in which the piston presses the friction plate.
[0028]
In the released state, as shown in FIG. 2, the tip of the protruding wall portion 62 of the piston 47 is separated from the vertical wall portion 54 of the hub 50. The oil that has passed through the thrust bearing 60 passes from the space inside the protruding wall portion 62 of the piston through this separated portion, and passes from the plurality of holes 76 of the vertical wall portion 54 to the inner space of the outer cylindrical portion 51 as indicated by arrow a. Flowing. At this time, the oil is smoothly guided to the hole 76 by the guide 68 provided along the outer edge of the hole 76.
[0029]
Thus, the oil that has reached the inner space of the outer peripheral cylindrical portion 51 is guided to the friction plates 45 and 46 through the lubricating holes 77 provided in the outer peripheral cylindrical portion, and sufficiently lubricates between the friction plates that are sliding with each other. To do.
A small amount of oil also flows from the narrow gap between the protruding wall 62 and the guide 68 to the friction plate as indicated by an arrow b.
The oil that has been lubricated is then discharged from the discharge hole 78 of the clutch drum 41.
[0030]
Next, in the fastened state, as shown in FIG. 3, pressure oil is supplied to the cylinder 48 to move the piston 47, and the tip of the protruding wall portion 62 approaches the vertical wall portion 54 of the hub 50, and the protruding wall The gap between the space inside the portion and the hole 76 in the vertical wall portion is narrowed.
Thereby, in the fastening state in which the friction plates 45 and 46 are pressed to be integrated and do not slide between each other, the oil supply to the friction plate portion is reduced.
[0031]
The embodiment is configured as described above. In the clutch in which the friction plates 45 and 46 meshing with the splines 42A and 52 formed in the spline portion 42 of the clutch drum and the outer peripheral cylinder portion 51 of the hub are alternately arranged, the friction plate is pressed. The piston 47 is provided with a protruding wall portion 62 extending toward the vertical wall portion 54 of the hub so that the tip of the protruding wall portion 62 approaches the vertical wall portion 54 when the piston 47 presses the friction plates 45, 46. In addition, a plurality of holes 76 are provided in the vertical wall portion 54 radially outside the protruding wall portion 62 of the piston, and a lubricating hole 77 is provided in the outer peripheral cylinder portion 51.
[0032]
As a result, when the clutch is released, the tip of the protruding wall portion 62 is separated from the vertical wall portion 54, from the space inside the protruding wall portion to the inner space of the outer peripheral cylinder portion 51 from the hole 76 of the vertical wall portion, and An oil passage that is led to the friction plate portion through the lubricating hole 77 is formed. At this time, the oil is efficiently guided to the hole 76 in the vertical wall portion by the guide 68 provided along the outer edge of the hole 76 in the vertical wall portion.
Further, when the clutch is engaged, the tip of the protruding wall portion 62 approaches the vertical wall portion to narrow the gap, and the amount of oil flowing out from the space inside the protruding wall portion 62 into the hole 76 in the vertical wall portion is reduced.
[0033]
Therefore, when the clutch is engaged, the oil supply to the friction plate portion is reduced, the amount of oil supply to other portions requiring lubrication is increased, and a large amount of oil is supplied to the friction plate portion when the clutch requiring the most lubrication is released. It has the effect.
Since the flow rate of the oil is controlled by changing the gap between the protruding wall portion 62 of the piston and the vertical wall portion 54 of the hub, the oil supply ring groove of the rotating shaft and the oil hole of the piston are communicated. Since the axial length of the sliding surface of the piston is shorter than that of the conventional one to be shut off, and there is no need to provide an extended cylindrical portion with a long dimension as in the conventional example, the axial size of the transmission is Can be small.
[0034]
In addition, although the Example demonstrated the lubrication structure of the clutch as a friction engagement apparatus, this invention is not limited to a clutch, It is applied also to the lubrication of the brake by which rotation is locked by fastening. Therefore, in this invention, a drum shall also contain a stationary-side member.
[0035]
【The invention's effect】
As described above, according to the present invention, the friction plates, which are spline-fitted on the drum inner periphery and the hub outer periphery, are alternately arranged, and the piston and the hub that presses the friction plate are moved forward and backward to rotate the drum and the hub integrally. In a friction engagement device that is in a released state that allows rotation, lubricating oil discharged from an axial oil passage inside the rotating shaft of the drum to the outside of the rotating shaft is guided to a space on the inner peripheral side of the spline portion of the hub. A lubricating structure for supplying lubricating oil between the friction plates through a lubricating hole extending in the radial direction and penetrating the inside and outside of the piston is partitioned by the friction plate side surface of the piston and the vertical wall portion extending in the radial direction of the hub. A first oil passage, a hole that penetrates through the hub wall so as to guide oil from the first oil passage into the inner circumferential space of the spline portion of the hub, and the radial passage through the hub vertical wall portion side of the piston. Vertical wall within the hole position And a projecting wall portion projecting toward the piston, and when the piston advances, the projecting wall portion approaches the vertical wall portion of the hub, and the lubrication structure reduces the amount of lubricating oil flowing out of the through-hole from when the piston is retracted. Therefore, the lubricating oil supply to the friction plate portion is appropriately controlled according to the fastening / release, and the axial length of the sliding surface of the piston can be shortened.
[0036]
In addition, since the lubricating oil is supplied from the inner diameter direction to the friction plate, uniform and sufficient lubrication is achieved, and adjacent members can be disposed in the inner space of the outer peripheral cylindrical portion of the hub, and the axial size of the entire transmission can be reduced. Can be small.
[0037]
Furthermore, by providing a guide along the outer edge of the plurality of holes on the side wall of the vertical wall portion facing the piston, the oil is efficiently guided to the plurality of holes.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention.
FIG. 2 is an enlarged view of a clutch portion showing the flow of oil in a clutch released state.
FIG. 3 is an enlarged view showing an engaged state of a clutch.
FIG. 4 is a cross-sectional view showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Transmission case 12, 18 Support hole 13, 14, 71 Oil path 15 Output shaft 16 Output gear 17 Outer end 19 Shoulder part 20 Tube part 21 Outer peripheral surface 22 Spring holder 23 Return spring 24 Snap ring 25 Input shafts 30, 31 Bearing 33 Parking gear 34 Disc part 35 Teeth 36 Recess 40 Clutch 41 Clutch drum 42A, 52 Spline 43 Outer wall part 44 Bottom wall part 45, 46 Friction plate 47 Piston 48 Cylinder 49 Inner peripheral surface 50 Hub 51 Outer peripheral cylinder part 53 Inner peripheral wall Portion 54 Vertical wall portion 58 Pressing portion 60 Thrust bearing 62 Protruding wall portions 66, 67 Seal ring 68 Guides 70, 72, 73 Axial oil passage 74 Oil hole 76 Hole 77 Lubrication hole 78 Discharge hole

Claims (2)

The friction plate that is spline-fitted on the inner periphery of the drum and the friction plate that is spline-fitted on the outer periphery of the hub are alternately arranged, and the piston that can press these friction plates is provided in the drum. As a result, the friction plates are pressed against each other and the drum and the hub are rotated together, and the pistons are retracted by releasing the hydraulic pressure to release the friction plates from each other, and the drum and the hub are rotated relative to each other. A lubricating structure that supplies lubricating oil between the friction plates of the friction engagement device that is allowed to be released, and lubricated from an axial oil passage inside the rotating shaft of the drum to the outside of the rotating shaft The friction engaging device supplies oil to the space between the friction plates through a lubrication hole that guides oil into the space on the inner peripheral side of the spline portion of the hub and extends radially in the spline portion and penetrates the inside and outside of the spline portion. In the structure,
A first oil passage defined by a side surface of the friction plate of the piston and a vertical wall portion extending in the radial direction of the hub;
A hole penetrating the wall of the hub so as to guide oil from the first oil passage to the inner circumferential space of the spline portion of the hub;
On the side of the vertical wall portion of the hub of the piston, a projecting wall portion projecting toward the vertical wall portion within the hole position penetrated in the radial direction,
When the piston advances, the protruding wall portion approaches the vertical wall portion of the hub so that the amount of lubricating oil flowing out from the through-hole is reduced compared to when the piston is retracted. Lubrication structure of the device. On the side wall facing the piston of the vertical wall portion, said hole is a through the wall of the hub is provided with a plurality of guide is provided along the outer edge of the plurality of holes, said first oil The lubricating structure for a friction engagement device according to claim 1, wherein the lubricating oil is configured to guide oil passing through a passage to the plurality of holes.

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