KR20100059381A - Clutch and automatic transmission provided with the same - Google Patents

Abstract

PURPOSE: A clutch and an automatic transmission thereof are provided to reduce the length and improve the assembling property by forming a single piston module after combining a piston and a return spring with a balance wall. CONSTITUTION: A clutch retainer is arranged on an input axis and forms a clutch space. A piston(205) forms a piston chamber between a clutch retainer and generates the friction force between a clutch plate and a friction disc with the fluid pressure inputted to the piston chamber. A balance wall(230) is arranged in an opposite position of a piston, and forms a balance chamber between pistons. A return spring(220) is supported with the piston and the balance month, and provides the elastic force opposing against the hydraulic pressure inputted to the piston chamber.

Description

CLUTCH AND AUTOMATIC TRANSMISSION PROVIDED WITH THE SAME}

The present invention relates to a clutch for an automatic transmission, and more particularly, to a clutch that combines a piston, a return spring and a balance wall to form one piston module, thereby improving assembly and shortening the overall length.

As is well known, an automatic transmission is a device that automatically shifts to an appropriate shift stage according to a driving state of a vehicle. In order to implement such automatic transmission, the automatic transmission includes a planetary gear set including sun gear, ring gear, and planet carrier as its operating members. and at least one set, and a plurality of friction elements, such as a clutch and a brake, are provided to control the operation of such operating members.

The automatic transmission is provided with a hydraulic control system for hydraulically controlling such friction elements. Therefore, the clutches and brakes determined according to the shift stages are controlled to be engaged or released by the hydraulic control system, thereby implementing each shift stage.

Among the friction elements, the clutch serves to transfer power of the engine to the actuating member of the planetary gear set or to mediate power transmission between the actuating members.

7 is a cross-sectional view of a conventional clutch.

As shown in FIG. 7, a typical automatic transmission includes a clutch 100 on an input shaft (not shown).

The clutch 100 forms a piston chamber 120 between the clutch retainer 105 and the clutch retainer 105 disposed on the input shaft to form a clutch space. A piston 125 operated by hydraulic pressure or pneumatic pressure input to the chamber 120, and disposed at a position opposite to the piston chamber 120 of the piston 125. It includes a return spring (145) for applying a restoring force to the piston (120). Sealing members 180 and 185 are interposed between the clutch retainer 105 and the piston 125. The airtightness of the piston chamber 120 is maintained by the sealing members 180 and 185.

In addition, the clutch hub 140 in the automatic transmission includes a plurality of friction disks 155 in a spline structure on an outer circumferential surface thereof, and the clutch retainer 105 includes a plurality of clutch hubs 140. Clutch plates 150 are provided on the inner circumferential surface thereof in a splined structure. The friction disks 155 and the clutch plates 150 are alternately arranged.

The clutch retainer 105 is formed with a first oil passage 160 to supply oil to the piston chamber 120. In this way, the oil supplied to the piston chamber 120 presses the piston 125 to the right in the drawing to overcome the elastic force of the return spring 145 and moves the piston 125 to the right in the drawing.

Accordingly, the piston 125 presses the clutch plates 150 along the axial direction of the input shaft, whereby the clutch plates 150 and the friction disks 155 engage by the friction force therebetween. Done. By this process, power is transmitted between the input shaft and the clutch hub 140.

When the oil supply to the piston chamber 120 through the first oil passage 160 is stopped, the piston 125 is moved to the left side in the drawing by the restoring force of the return spring 145, thereby engaging the clutch plate S 150 and friction disks 155 are disengaged from their engaged state.

However, even when the oil supply to the piston chamber 120 through the first oil passage 160 is stopped, it is difficult to guarantee that the oil in the piston chamber 120 is completely discharged. At this time, since the input shaft in the automatic transmission rotates at a very high speed, the oil in the piston chamber 120 is moved in the radial direction under centrifugal force. Therefore, centrifugal pressure is generated by the centrifugal force of the oil, and the centrifugal pressure may act to pressurize the piston 125.

In this case, a situation may arise in which the piston 125 is not sufficiently restored as desired, and slightly pressurizes the clutch plates 150. In this case, the engagement states of the clutch plates 150 and the friction disks 155 are not sufficiently released and cause continuous friction. Frictional slip between the clutch plates 150 and the friction disks 155 degrades the durability of the automatic transmission and increases power loss.

In order to reduce frictional slip between the clutch plates 150 and the friction disks 155, a balance chamber 135 may be formed opposite the piston chamber 120 of the piston 125. That is, the piston chamber 120 is caused by the oil in the balance chamber 135 to generate centrifugal force corresponding to the centrifugal hydraulic pressure of the oil remaining in the piston chamber 120, the direction of which is opposite to the centrifugal hydraulic pressure. It is possible to prevent the movement of the piston 125 by the centrifugal force of the oil inside.

Therefore, as shown in FIG. 7, the balance chamber 135 is disposed between the balance wall 130 and the piston 125 by installing a balance wall 130 opposite the piston 125 of the return spring 145. ). The balance chamber 135 is supplied with oil through the second oil passage 165 such that oil always remains.

In addition, the inner end of the balance wall 130 is supported by the snap ring 170 provided on the clutch retainer 105, and the sealing member 190 is interposed between the outer end and the piston 125.

However, when the balance chamber 135 is formed in this manner, the axial distance between the balance wall 130 and the piston 125 should be secured in consideration of the operation of the piston 125. In addition, since the second oil passage 165 for supplying oil to the balance chamber 135 must be formed in the clutch retainer 105, the axial distance between the balance wall 130 and the piston 125 has to be long.

Due to this necessity, the axial length L 'of the clutch 100 becomes long. For example, the axial length L 'of the conventional clutch 100 was 39 mm. The longer clutch 100 is a factor in lengthening the overall length of the automatic transmission.

In general, considering that at least three clutches are provided in the automatic transmission, the increase in length generated by one clutch has an effect of more than three times the increase in the overall length of the automatic transmission.

In recent years, multiple gear ratios of all-wheel drive automatic transmissions have been achieved. In view of this tendency, the increase in the total length of the automatic transmission makes it difficult to mount the automatic transmission in the engine room. It will be. Therefore, if the axial length required for the clutch can be reduced, the overall length of the automatic transmission can be reduced, and in this case, the automatic transmission for implementing more shift stages can be mounted on the front wheel drive vehicle.

Meanwhile, in order to assemble the conventional clutch 100, as shown in FIG. 8, the piston 125 is disposed in the clutch space of the clutch retainer 105, and the clutch retainer 105 of the piston 125 is disposed. Opposite of, the return spring 145 and the balance wall 130 are disposed such that the return spring 145 is positioned between the piston 125 and the balance wall 130. Thereafter, the snap ring 175 is inserted into the groove formed in the clutch retainer 105 to form a clutch assembly as shown in FIG. 9, and the clutch plate 150 and the friction disk 155 are mounted. Therefore, there is a problem in that assembling is deteriorated since the assembly of the parts after placing the parts in a predetermined position is performed correctly.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a clutch with improved assembly by forming a module by combining a piston, a return spring and a balance wall.

Another object is to provide a clutch having a short axial length by providing a centrifugal force generating means in the balance chamber to eliminate the oil passage supplied to the balance wall.

In addition, there is another object to provide an automatic transmission in which the overall length is shortened by mounting the above clutch on the automatic transmission.

Clutch according to the embodiments of the present invention for achieving this object is to selectively transmit the power of the input shaft to the clutch hub by the friction force between the clutch plate and the friction disk, the clutch disposed on the input shaft to form a clutch space Retainer; A piston which forms a piston chamber with the clutch retainer, and generates a friction force between the clutch plate and the friction disk by hydraulic pressure input to the piston chamber; A balance wall disposed at a position opposite said piston chamber of said piston, said balance wall defining a balance chamber therebetween; And a return spring supported by the piston and the balance wall and providing the piston with an elastic force against the hydraulic pressure input to the piston chamber, wherein the piston, the balance wall, and the return spring form a single piston module. The piston module is mounted to the clutch retainer in a coupled state so that the piston module may include centrifugal force generating means in the balance chamber so that the balance hydraulic pressure is not supplied from outside the balance chamber.

Thus, the oil passage for supplying oil to the balance chamber is deleted, so that the length of the clutch is shortened. In addition, since only the piston module needs to be mounted on the clutch retainer, assemblability is improved.

The clutch may further comprise a support ring mounted on the clutch retainer to limit the axial movement of the balance wall.

The support ring may be supported by a snap ring mounted on the clutch retainer.

In the clutch according to the first embodiment of the present invention, the inner end of the piston and the inner end of the balance wall are connected by a resilient joining member that is radially spaced to allow relative displacement of the piston and the balance wall. It may be.

The bonding member may be mounted to be in close contact with the inner diameter of the clutch retainer, and may be formed to surround the inner end of the balance wall to seal the balance chamber.

The piston module further includes a sealing ring in close contact with the outer diameter surface of the piston, wherein the outer end of the balance wall and the sealing ring are radially spaced apart and elastic so as to allow relative displacement of the piston and the balance wall. It may be connected by a connecting member. Thus, even if the piston is actuated by hydraulic pressure and the axial length of the balance chamber is reduced, interference between the piston and the balance wall does not occur.

In order to seal the balance chamber, a sealing member may be interposed between the sealing ring and the outer diameter surface of the piston.

The centrifugal force generating means may be oil or silicone oil.

The centrifugal force generating means can absorb the expansion of the centrifugal force generating means even if the volume of the balance chamber is reduced by the piston operation by filling the remaining volume in the balance chamber.

In the clutch according to the second embodiment of the present invention, the inner end of the piston and the inner end of the balance wall and the outer diameter surface of the piston and the outer end of the balance wall are each formed in the balance chamber in a radially spaced state. The return spring may be included in the balance chamber. The piston, the balance wall and the return spring are integrally molded through elastic centrifugal force generating means to form a module. The centrifugal force generating means has a property to deform radially by the centrifugal force, but the deformation is suppressed by the outer diameter portion of the piston and the balance wall, thereby applying a centrifugal balance force against the centrifugal hydraulic pressure of the piston chamber to the piston. That is, the centrifugal force generating means is bonded to the piston and the balance wall to form a single piston module and serves to generate the centrifugal force. In some cases, the return spring may be deleted so that the centrifugal force generating means also serves as the return spring. The centrifugal force generating means may be attached to the inner surface of the piston and the balance wall to connect the inner end of the piston and the inner end of the balance wall and the outer diameter surface of the piston and the balance wall. Thus, even if the axial length of the balance chamber is reduced by the operation of the piston, no interference occurs between the piston and the balance wall.

The centrifugal force generating means is in close contact with the inner diameter of the clutch retainer through a gap between the inner end of the piston and the balance wall and the inner end of the balance wall, thereby maintaining the airtightness of the piston chamber.

A sealing member for sealing the piston chamber may be interposed between the outer diameter surface of the piston and the clutch retainer.

The centrifugal force generating means may be rubber or silicone.

An automatic transmission according to an embodiment of the present invention includes one or more clutches operated by hydraulic pressure, and the one or more clutches may be clutches according to embodiments of the present invention.

As described above, according to the present invention, the oil passage for supplying oil to the balance chamber is deleted, so that the length of the clutch is shortened.

By combining the piston, return spring and balance wall to form one piston module, only the piston module needs to be mounted on the clutch retainer, thus improving assembly.

In addition, by using the clutch as described above it is possible to shorten the overall length of the automatic transmission, the assembly process of the clutch is simplified, the assembly time can be shortened to reduce the production cost of the automatic transmission.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a clutch according to embodiments of the present invention.

The clutch according to the embodiments of the present invention has been described in the case where it is applied to an automatic transmission for convenience of description, but is not limited thereto and may be applied to a general machine.

In the automatic transmission to which embodiments of the present invention are applied, a clutch 1 is disposed on an input shaft (not shown) in a transmission case.

The input shaft should not be construed as referring to a rotating shaft directly receiving power from the engine. Since a plurality of rotary shafts may be disposed in the automatic transmission, and a clutch may be disposed on any of the rotary shafts, the terminology of the input shaft described in the detailed description and claims of the present invention is disposed in the automatic transmission to rotate and planetary gears. It should be interpreted as referring to any axis of rotation on which the set can be placed.

The clutch 1 disposed on the input shaft forms a piston chamber 22 between the clutch retainer 10 and the clutch retainer 10 disposed on the input shaft of the automatic transmission to form a clutch space. It includes a piston module 20, and a clutch hub 30 that is operated by the hydraulic pressure input to the piston chamber 22.

The clutch retainer 10 has an inner diameter portion 12 formed in an axial direction so as to be mounted on an input shaft, and a waist perpendicular to the inner diameter portion 12 and extending radially outward from the inner diameter portion 12. A portion 14, an outer diameter portion 16 formed in the axial direction in the same direction as the inner diameter portion 12, and a clutch plate mounting portion attached to the outer circumferential surface of the outer diameter portion 16 by welding or the like and extending in the axial direction (18).

In addition, the clutch hub 30 is provided with a spline structure on the outer circumferential surface of the friction disks 34, and the clutch plate mounting portion 18 of the clutch retainer 10 has the clutch plates 32 on the inner circumferential surface thereof. It has a spline structure. These friction disks 34 and clutch plates 32 are alternately arranged. In addition, the clutch plate 32 disposed at the opposite end of the piston module 20 of the clutch plates 32 is limited in the axial movement by the snap ring 36. Thus, the piston module 20 presses against the friction disks 34 and the clutch plates 32 so that a friction force can be generated therebetween.

An oil passage 40 is formed in the inner diameter portion 12 of the clutch retainer 10 so that oil is supplied to the piston chamber 22. In addition, the piston module 20 is supported by a support ring 42 mounted on the inner diameter portion 12 and the support ring 42 is supported by a snap ring 44 mounted on the inner diameter portion 12 to the The axial movement of the inner diameter of the piston module 20 is limited.

In addition, a first sealing member 46 is interposed between the outer diameter portion 16 of the clutch retainer 10 and the outer diameter portion of the piston module 20 to maintain the airtightness of oil input to the piston chamber 20. .

Hereinafter, a piston module according to embodiments of the present invention will be described in detail. 2 is a cross-sectional view of the piston module according to the first embodiment of the present invention.

The piston module 20 according to the embodiment of the present invention is a piston 205, the balance wall 230, and the return spring 220 is combined to be manufactured as one module.

As shown in FIG. 2, the piston module 20 according to the first embodiment of the present invention includes a piston 205, a balance wall 230, a return spring 220, and a sealing ring 240.

The piston 205 forms a piston chamber 22 between the clutch retainer 10, and presses the clutch plate 32 and the friction disk 34 by oil input to the piston chamber 22 to apply frictional force. Generate. The piston 205 has its inner diameter inclined in the opposite direction of the clutch retainer 10 to form an inclined surface 207. This inclined surface 207 facilitates the entry of oil into the piston chamber 22 through the oil passage 40. A joining member 215 is attached to the inner end of the piston 22 and extends in the axial direction. The joining member 215 is mounted to be in close contact with the inner diameter portion 12 of the clutch retainer 10 to secure the airtightness of the piston chamber 22. In addition, the bonding member 215 is formed to surround the inner end of the balance wall (230).

An axial extension 209 is formed in the outer diameter of the piston 205, and the axial extension 209 is in close contact with the outer diameter 16 of the clutch retainer 10. A first sealing member 46 is interposed between the axial extension portion 209 and the outer diameter portion 16 of the clutch retainer 10 to secure the airtightness of the piston chamber 22.

The axial extension 209 is bent radially outward to form a radial extension 211 and a pressing portion 213 is formed at the end thereof. The pressurizing portion 213 is configured to pressurize the clutch plate 32 when oil flows into the piston chamber 22.

The balance wall 230 is disposed at a position opposite to the piston chamber 22 of the piston 205 and forms a balance chamber 250 between the piston 205. The inner end of the balance wall 230 is bent in the direction opposite to the balance chamber 250 to form the recess 232. The concave portion 232 is for the piston module 20 to be easily supported by the clutch retainer 10 and at the same time for sealing with the retainer 10. The recess 232 is wrapped by the bonding member 215, thereby maintaining the airtightness of the balance chamber 250. In addition, the joining member 215 is made of a material such as elastic rubber, the inner end of the piston 205 and the inner end of the balance wall 230 is radially spaced apart so that the piston 205 hydraulic pressure It is operated by to enable the relative displacement of the piston 205 and the balance wall 230 when moving to the right in the figure. The recess 232 is supported by the support ring 42 and the snap ring 44, thereby limiting the axial movement of the balance wall 230.

The outer end of the balance wall 230 is attached to the elastic connecting member 234.

In addition, the balance chamber 250 includes centrifugal force generating means for generating centrifugal force by rotation of the clutch 1 and applying the generated centrifugal force to the piston 205. In the first embodiment of the present invention, since the balance chamber is sealed as described below, the centrifugal force generating means may be oil 260 or silicone oil 260. When the piston 205 is actuated, the balance chamber 250 can be compressed, so that the centrifugal force generating means 260 is filled in the balance chamber 250 while leaving a constant volume of spare space 280 filled with the piston ( Even if the volume of the balance chamber 250 is reduced by the operation of the 205, the expansion of the centrifugal force generating means 260 can be absorbed.

The return spring 220 is disposed between and supported between the piston 205 and the balance wall 230 and provides the piston 205 with an elastic force against hydraulic pressure input to the piston chamber 22. Here, the return spring 220 is illustrated as a disc spring, but is not limited thereto, and any means capable of generating a restoring force on the piston 205 such as a coil spring may be used.

The sealing ring 240 is in close contact with the axial extension 209 (ie, the outer diameter surface) of the piston 205, and a second sealing is formed between the sealing ring 240 and the axial extension 209. A member 242 is interposed to seal the balance chamber 250. In addition, the sealing ring 240 is radially spaced apart from the outer end of the balance wall 230 and connected to the resilient connecting member 234, the piston 205 is moved to the right in the drawing by hydraulic pressure The relative displacement of the piston 205 and the balance wall 230 is then enabled.

As mentioned above, in the present invention, since the balance chamber 250 is sealed and the sealed balance chamber 250 includes centrifugal force generating means, an oil passage for supplying oil to the balance chamber 250 can be omitted. As a result, the axial length of the clutch 1 is reduced.

As shown in FIG. 3A, when oil is not supplied to the piston chamber 22 and the clutch 1 rotates, the centrifugal force generating means 260 in the balance chamber 250 is pushed out of the radius under the centrifugal force. . At this time, since the balance wall 230 is limited in the axial movement by the support ring 42 and the snap ring 44, the centrifugal force generating means 260 exerts a centrifugal force on the piston 205 and thus the clutch 1 Complete liberation).

As shown in FIG. 3B, when oil is supplied to the piston chamber 22, the piston 205 overcomes the elastic force of the return spring 220 and the centrifugal force of the centrifugal force generating means 260 and moves downward in the drawing to clutch the clutch. The plate 32 and the friction disks 34 are pressed. At this time, the sealing ring 240 moves downward in the drawing together with the piston 205 to maintain the sealing of the balance chamber 250.

Since the inner end of the piston 205 and the inner end of the balance wall 230 and the outer end of the sealing ring 240 and the balance wall 230 are radially spaced from each other, the piston 205 is formed by the balance wall 230. Movement is not interfered. In addition, the inner end of the piston 205 and the inner end of the balance wall 230 are connected by an elastic bonding member 215 and the outer end and the sealing ring 240 of the balance wall 230 are elastic connecting members 234. Since it is connected by), even if the piston 205 moves, the balance wall 230 does not move, only the bonding member 215 and the connecting member 234 is deformed.

4 is a sectional view of a piston module according to a second embodiment of the present invention.

The piston module according to the second embodiment of the present invention is similar in structure to the piston module according to the first embodiment of the present invention. Therefore, only the differences will be described in detail.

As shown in FIG. 4, the piston module 20 according to the second embodiment of the present invention includes a piston 205, a balance wall 230, and a return spring 220.

The piston 205 has its inner diameter inclined in the opposite direction of the clutch retainer 10 to form an inclined surface 207. This inclined surface 207 facilitates the entry of oil into the piston chamber 22 through the oil passage 40. An axial extension 209 is formed in the outer diameter of the piston 205, and the axial extension 209 is in close contact with the outer diameter 16 of the clutch retainer 10. A third sealing member 230 is interposed between the axial extension portion 209 and the outer diameter portion 16 of the clutch retainer 10 to secure the airtightness of the piston chamber 22, and according to the first embodiment of the present invention. As in the embodiment, a groove may be formed in the clutch retainer 10 and the first sealing member 46 may be interposed therebetween.

The axial extension 209 is bent radially outward to form a radial extension 211 and a pressing portion 213 is formed at the end thereof.

The inner end of the balance wall 230 is bent in the direction opposite to the balance chamber 250 to form the recess 232. The inner end of the piston 205 and the inner end of the balance wall 230 are spaced in the radial direction so that the relative displacement of the piston 205 and the balance wall 230 is possible. The concave neck 232 is supported by the support ring 42 and the snap ring 44, thereby limiting the axial movement of the balance wall 230.

The outer end of the balance wall 230 is also radially spaced apart from the axial extension 209 of the piston 205 to allow relative displacement of the piston 205 and the balance wall 230.

Therefore, the balance chamber 250 in the piston module 20 according to the second embodiment of the present invention is not a sealed structure. Accordingly, the centrifugal force generating means 270 entering the balance chamber 250 uses a fluid solid rather than a fluid. The centrifugal force generating means 270 may be very soft and flowable rubber or silicone. The centrifugal force generating means 270 is integrally formed with the piston 205, the balance wall 230 and the return spring 220 to form the inner end of the piston 205 and the inner end of the balance wall 230 and the piston 205. The outer diameter surface of and the outer end of the balance wall 230 is connected to each other. In addition, since rubber or silicon is used as the centrifugal force generating means 270, oil does not need to be supplied to the balance chamber 230. Therefore, the oil passage for supplying oil to the balance chamber 230 can be omitted, so that the axial length of the clutch 1 is shortened.

On the other hand, the centrifugal force generating means 270 comes out of the balance chamber 250 through a gap between the inner end of the piston 205 and the inner end of the balance wall 230, and thus out of the balance chamber 250. The centrifugal force generating means 270 surrounds the inner end of the balance wall 230 and is bonded to the inner diameter portion 12 of the clutch retainer 10 to maintain the airtightness of the piston chamber 22.

The return spring 220 is disposed between the piston 205 and the balance wall 230 and provides the piston 205 with an elastic force against hydraulic pressure input to the piston chamber 22. The return spring 220 may be integrally formed with the centrifugal force generating means 270.

The centrifugal force generating means 270 is made of a very soft material and has a characteristic of deforming radially by the centrifugal force, but is suppressed in its deformation by the outer diameter portion of the piston 205 and the balance wall 230. A centrifugal balancing force against the centrifugal hydraulic pressure of 22 is applied to the piston 205. In addition, in some cases, the return spring 220 may be removed to allow the centrifugal force generating means 270 to simultaneously perform the function of applying the elastic force to the piston 205 and generating the centrifugal force.

5 is a cross-sectional view illustrating a state in which the clutch module and the clutch retainer are disassembled in the clutch according to the embodiments of the present invention, and FIG. 6 is a state in which the clutch module and the clutch retainer are assembled in the clutch according to the embodiments of the present invention. It is a cross-sectional view.

As shown in FIG. 5, the clutch 1 according to the embodiments of the present invention forms an oil passage 40 in the clutch retainer 10 and mounts the first sealing member 46, and then the piston 205. ), The balance wall 230, and the piston module 20 coupled with the return spring 220 is inserted into the clutch space. Thereafter, the support ring 42 and the snap ring 44 are mounted to assemble the piston module 20 to the clutch retainer 10 to produce a clutch assembly as shown in FIG. 6. Thereafter, the clutch 1 is manufactured by attaching the clutch plate 32 and the friction disk 34. Therefore, the number of parts to be assembled is reduced and the assemblability is improved.

In addition, the axial length L of the clutch 1 by omitting the oil passage for supplying oil to the balance chamber 250 and connecting the piston 205 and the balance wall 230 with a resilient material to prevent mutual interference from occurring. ) Becomes shorter. For example, the axial length L of the clutch 1 according to the embodiments of the present invention is 32 mm, and the overall length is shortened by 7 mm compared to 39 mm, which is the length L 'of the conventional clutch.

In this way, when the axial length is shortened and the assembly is improved, the automatic transmission is equipped with a clutch, which greatly shortens the overall length of the automatic transmission, and the assembly time of the clutch is also shortened, thereby reducing the production cost of the automatic transmission.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and easily changed and equalized by those skilled in the art from the embodiments of the present invention. It includes all changes to the extent deemed acceptable.

1 is a cross-sectional view of a clutch according to embodiments of the present invention.

2 is a cross-sectional view of the piston module according to the first embodiment of the present invention.

3 is a cross-sectional view showing a release state and a coupled state of the clutch according to the first embodiment of the present invention.

4 is a sectional view of a piston module according to a second embodiment of the present invention.

5 is a cross-sectional view showing a state in which the clutch module and the clutch retainer are disassembled in the clutch according to the embodiments of the present invention.

6 is a cross-sectional view showing a state in which the clutch module and the clutch retainer are assembled in the clutch according to the embodiments of the present invention.

7 is a cross-sectional view of a conventional clutch.

8 is a cross-sectional view illustrating a state in which a clutch retainer, a piston, a return spring, and a balance wall are disassembled in a conventional clutch.

9 is a cross-sectional view illustrating a state in which a clutch retainer, a piston, a return spring, and a balance wall are assembled in a conventional clutch.

Claims (14)

In the clutch for selectively transmitting the power of the input shaft to the clutch hub by the friction force between the clutch plate and the friction disk, A clutch retainer disposed on the input shaft to form a clutch space; A piston which forms a piston chamber with the clutch retainer, and generates a friction force between the clutch plate and the friction disk by hydraulic pressure input to the piston chamber; A balance wall disposed at a position opposite said piston chamber of said piston, said balance wall defining a balance chamber therebetween; And A return spring supported by the piston and the balance wall and providing the piston with an elastic force against hydraulic pressure input to the piston chamber; ≪ / RTI > The piston, the balance wall and the return spring are mounted to the clutch retainer in a coupled state to form one piston module, The piston module includes a centrifugal force generating means in the balance chamber so that the balance hydraulic pressure is not supplied from outside the balance chamber. The method of claim 1, And a support ring mounted on the clutch retainer to limit axial movement of the balance wall. 3. The method of claim 2, And the support ring is supported by a snap ring mounted on the clutch retainer. The method of claim 1, Clutch, characterized in that the inner end of the piston and the inner end of the balance wall is connected by a resilient joining member radially spaced so as to allow relative displacement of the piston and the balance wall. The method of claim 4, wherein The joining member is mounted in close contact with the inner diameter of the clutch retainer, characterized in that formed to surround the inner end of the balance wall for sealing the balance chamber. The method of claim 4, wherein The piston module further includes a sealing ring in close contact with the outer diameter surface of the piston, Clutch characterized in that the outer end of the balance wall and the sealing ring is connected by a resilient connecting member is radially spaced so as to allow relative displacement of the piston and the balance wall. The method of claim 6, Clutch, characterized in that for sealing the balance chamber, a sealing member is interposed between the sealing ring and the outer diameter surface of the piston. The method of claim 6, And said centrifugal force generating means is oil or silicone oil. The method of claim 8, And said centrifugal force generating means is filled in said balance chamber while leaving a constant volume of extra space. The method of claim 1, The inner end of the piston and the inner end of the balance wall and the outer diameter surface of the piston and the outer end of the balance wall respectively form a balance chamber in a radially spaced state, An elastic centrifugal force generating means is interposed between the piston and the balance wall, And the centrifugal force generating means is attached to the inner surface of the piston and the balance wall to connect the inner end of the piston and the inner end of the balance wall and the outer diameter surface of the piston and the balance wall. The method of claim 10, And the centrifugal force generating means is in close contact with the inner diameter portion of the clutch retainer via a gap between the inner end of the piston and the balance wall and the inner end of the balance wall. The method of claim 10, Clutch characterized in that the sealing member for sealing the piston chamber is interposed between the outer diameter surface of the piston and the clutch retainer. The method of claim 10, And said centrifugal force generating means is rubber or silicone. In an automatic transmission comprising one or more clutches operated by hydraulic pressure, The at least one clutch is an automatic transmission, characterized in that the clutch according to claim 1.

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