KR20150003976A - Brake - Google Patents

Abstract

The present invention relates to a brake which decreases the number of friction disk by increasing an operating force of a piston, or increases the efficiency of an automatic transmission by decreasing operational oil pressure. The brake of the present invention comprises: a connecting hub including an inside diameter part, a middle part, and an outside diameter part; a retainer arranged on the inside diameter part of the connecting hub, including a wall protruded toward the outside of a radius; a first piston arranged closely on an outside diameter of one part of the retainer, capable of moving in an axial direction by oil pressure supplied to a first piston chamber; a second piston moving with the first piston in the axial direction by oil pressure supplied to the first piston chamber and a second piston chamber, and pressurizing operation plates and friction disks; and a return spring.

Description

Break {BRAKE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a brake used in an automatic transmission or the like, and more particularly, to a brake that increases the operating force of a piston to reduce the number of friction discs or reduce the operating oil pressure to improve the efficiency of the automatic transmission.

As is known, the automatic transmission is a device that automatically shifts to an appropriate gear according to the running state of the vehicle. In order to realize such automatic shifting, a planetary gear set including a sun gear, a ring gear, and a planetary carrier as its operating members is provided in the automatic transmission. a plurality of clutches and a plurality of brakes are provided to control the operation of the actuating members.

In the automatic transmission, a hydraulic control system is provided to hydraulically control the clutch and the brake. Therefore, the clutches and brakes determined according to the respective speed change stages are controlled to be engaged or disengaged by the hydraulic control system, thereby realizing the respective speed change stages.

In the automatic transmission, the brake serves to stop or fix the operating member of the rotating planetary gear set so as not to rotate. Further, the clutch operatively connects the operating member of the planetary gear set to the input shaft or another operating member such that the two operating members rotate at the same rotational speed.

Such clutches and brakes are used not only in automatic transmissions but also in general machines for stopping the rotation member or transmitting rotational force.

Conventional clutches and brakes of an automatic transmission are designed to selectively connect two members capable of rotating relative to each other. For this purpose, a plurality of actuation plates are coupled to one member, and a plurality of friction discs are coupled to the other member, and the plurality of actuation plates and the plurality of friction discs are alternately arranged .

In addition, a piston is disposed to press the operation plate and the friction disk against each other by frictional force, and a piston chamber is formed to apply hydraulic pressure to the piston. Furthermore, a return spring is provided to provide a restoring force against the hydraulic pressure applied to the piston.

When oil is supplied to the piston chamber, the piston overcomes the restoring force of the return spring by hydraulic pressure and moves the piston to press the operating plate and the friction disk. Thereby, the operating plate and the friction disk engage with each other by the frictional force therebetween.

When the supply of oil to the piston chamber is interrupted, the piston moves in the opposite direction due to the restoring force of the return spring. Whereby the operative plate and the friction disk engaged with each other are disengaged from the engaged state.

However, clutches and brakes used in automatic transmissions and the like are continuously supplied with oil between the friction disk and the operating plate to cool the heat generated by the slip between the operating plate and the friction disk during engagement.

However, since the oil supplied for cooling is continuously supplied even when the clutch or the brake is scrambled, rotational resistance, that is, drag torque, is generated between the friction disk and the operating plate, .

This drag torque occupies up to 40% of the total power loss of an automatic transmission and is a major cause of reduced efficiency of the automatic transmission.

In order to reduce the drag torque, it is most preferable to reduce the number of friction discs used. However, in this case, there is a problem in that the torque capacity of the clutch or brake required can not be secured.

According to the conventional clutch or brake, it is necessary to increase the area of the piston or increase the number of friction discs in order to sufficiently secure the torque capacity. However, when the installation space of the clutch or brake is restricted as in the automatic transmission, it is difficult to increase the diameter of the piston. Therefore, the torque capacity is increased by increasing the number of friction discs. As a result, the drag torque is further increased Respectively.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a clutch or a brake for increasing the area of a piston by effectively arranging two pistons in a limited space, .

It is another object of the present invention to provide a clutch or brake capable of reducing the number of friction disks by ensuring sufficient torque capacity.

On the other hand, when the same torque capacity is maintained, the operating force of the piston increases due to the increased piston area, so that the hydraulic pressure for operating the clutch or the brake can be reduced. As a result, the driving loss of the oil pump that generates the working oil pressure can be reduced and the efficiency of the automatic transmission can be increased.

In order to achieve the above object, a brake according to an embodiment of the present invention includes a plurality of actuation plates coupled to a member, and a plurality of actuating plates coupled to the other member, And friction plates, wherein the actuation plates and the friction discs are frictionally engaged with each other to stop both the one member and the other member. However, the technical idea of the present invention is equally applicable to a clutch, and in the case of a clutch, the one member and the other member rotate at the same speed. Thus, in the present specification and claims, the term brake shall be construed as including a clutch.

The brake according to one embodiment includes a connecting hub including an inner diameter portion, an intermediate portion extending radially outward from one end of the inner diameter portion, and an outer diameter portion extending from the outer end of the intermediate portion in the same direction as the inner diameter portion; A retainer disposed on an inner diameter portion of the connection hub, the retainer including a wall protruding radially outward; A first piston disposed in close contact with an outer diameter of one side of the retainer and movable in an axial direction by an oil pressure supplied to the first piston chamber; A first radial extension extending in the axial direction by an oil pressure supplied to the second piston chamber, and a second radial extension extending from the outer end of the first radial extension, And an inner end of the second hub is in close contact with an inner circumferential surface of an outer circumferential portion of the hub and extends in a radially outward direction at an end of the axially extending portion so as to be in close contact with an outer end of the first piston. And a pressurizing portion extending radially outward from an end of the second radial extending portion to a position of the actuating plate, wherein the hydraulic pressure supplied to the first piston chamber and the second piston chamber is converted into a pressing force A second piston adapted to urge the actuation plates and the friction disks against each other; And a return spring having an outer diameter portion on the other side of the axially extending portion and applying a restoring force against the hydraulic pressure supplied to the piston chambers to the second piston.

The first piston may be fixed to the second piston by any means connecting two members such as welding, caulking, riveting, spline, serration, screw, bonding, and bonding.

A support means is mounted on an inner end of the second radial extension of the second piston, and the first piston can be supported by the step of the support means and the axially extending portion.

A sealing member may be interposed between the outer end of the first piston and the inner end of the second radial extending portion.

The first piston and the second piston may be disassembled and reassembled.

An insertion groove may be formed in the outer circumferential surface of the outer diameter portion of the connection hub, and a sealing member may be inserted into the insertion groove.

The sealing member may have a supply passage formed therein and a first oil passage communicating with the first piston chamber and the supply passage may be formed in the outer diameter portion of the connection hub.

The connecting hub or the retainer may be provided with a connecting passage communicating with the first piston chamber, and the retainer may be provided with the connecting passage and the second oil passage communicating with the second piston chamber.

The discharge passage may be formed in the axial extending portion of the second piston to discharge the oil in the space formed by the first piston, the retainer, and the axial extending portion.

A support means is mounted on the inner diameter portion of the connection hub, and the support means can support the return spring.

The brake according to another embodiment includes a connecting hub including an inner diameter portion, an intermediate portion extending radially outward from one end of the inner diameter portion, and an outer diameter portion extending from the outer end of the intermediate portion in the same direction as the inner diameter portion; A retainer disposed on an outer diameter portion of the connection hub, the retainer including a wall protruding radially inward; A first piston which is disposed in close contact with the inner diameter of one side of the retainer and is movable in the axial direction by an oil pressure supplied to the first piston chamber; An axially extending portion disposed on the inner diameter portion of the connection hub so as to be movable in the axial direction and a radially outer portion extending radially outward from an end of the axially extending portion, the outer peripheral surface of which is in close contact with the inner diameter of the other side portion of the retainer And a pressure portion protruding axially from the radial extension to the position of the actuating plate, the hydraulic pressure being supplied to the second piston chamber formed between the wall and the radial extension, A second piston adapted to convert the hydraulic pressure supplied to the piston chamber into a pressing force to press the operating plates and the friction discs against each other; And a return spring disposed between the first piston and the retainer to apply a restoring force against the hydraulic pressure supplied to the piston chambers to the first piston.

The first piston may be fixed to the second piston by any means of connecting two members such as welding, caulking, press fitting, spline, serration, screw, rivet,

On the axially extending portion of the second piston is mounted a support means, the first piston being supported by a step formed in the support means and the axially extending portion and being movable with the second piston have.

A sealing member may be interposed between the inner end of the first piston and the outer diameter surface of the axially extending portion.

The first piston and the second piston can be reassembled after disassembly.

One side of the retainer is supported by the intermediate portion of the connecting hub, and the other side of the retainer is supported by a supporting member mounted on the outer diameter portion of the connecting hub.

The first piston chamber and the second piston chamber may communicate with each other by a connection passage formed in the retainer.

The connection passage may be formed on the inner surface of the outer diameter portion of the connection hub.

The axially extending portion of the second piston may be formed with a discharge passage to discharge the oil in the space formed by the axially extending portion, the wall, and the first piston.

As described above, according to the present invention, two pistons are separated and arranged in a limited space by a retainer, and the two pistons move together to increase the area of the piston, thereby ensuring sufficient torque capacity.

Further, by securing sufficient torque capacity, it is possible to reduce the number of friction disks and reduce the drag torque. In addition, it is possible to reduce the operating oil pressure by an extra torque capacity to reduce the power loss in the oil pump, thereby increasing the efficiency of the automatic transmission.

1 is a sectional view of a brake according to a first embodiment of the present invention.
2 is a cross-sectional view of a brake according to a second embodiment of the present invention.
3 is a cross-sectional view of a brake according to a third embodiment of the present invention.

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

Although the brake according to the embodiments of the present invention is applied to an automatic transmission for convenience of explanation, the present invention is not limited to this, but may be applied to a power transmission apparatus and a general machine. Although the brake has been described in the present specification, it will be appreciated that the clutch can also be applied. Thus, in the present specification and claims, the term brake shall be construed as including a clutch.

1 is a sectional view of a brake according to a first embodiment of the present invention.

1, the brake 1 according to the first embodiment of the present invention includes a connecting hub 10, a retainer 40, a first piston 30, a second piston 50, a return spring (not shown) 70, actuating plates 92 and friction discs 82. In addition, the first piston 30, the second piston 50, and the retainer 40 may be assembled in advance to form one piston module.

The connecting hub 10 forms the space of the brake 1 and includes the inner diameter portion 12, the intermediate portion 14 and the outer diameter portion 16 and is formed as a whole in the shape of a letter "C".

The inner diameter portion 12 is formed to extend in the axial direction.

The intermediate portion 14 is formed so as to extend radially outward from one end of the inner diameter portion 12. If necessary, the intermediate portion 14 may be partially bent in the axial direction and then extended radially outward.

The outer diameter portion 16 is connected to an outer end of the intermediate portion 14 and extends in the axial direction in the same direction as the inner diameter portion 12. An insertion groove 20 may be formed on the outer circumferential surface of the outer diameter portion 16 of the connection hub 10 and a sealing member 94 may be inserted into the insertion groove 20. The seal member 94 may be provided with a supply passage 96 for supplying oil to the first piston chamber 24 and the outer diameter portion 16 may be provided with the supply passage 96, A first oil passage 18 communicating with the first oil passage 24 may be formed. However, the present invention is not limited thereto. The first oil passage 18 may be supplied with oil directly to the first piston chamber 24 without passing through the sealing member 94.

The connection hub (10) may be provided with a connection passage (22) communicating with the first piston chamber (24).

The retainer 40 is disposed on the inner diameter portion 12 of the connecting hub 10 and includes a wall 42 protruding radially outward. The retainer 40 may have a second oil passage 44 communicating with the connection passage 22 and the second piston chamber 64. The connection passage 22 may be formed in the inner diameter portion of the retainer 40 without being formed in the connection hub 10. A sealing member 65 is interposed between the inner diameter portion 12 of the connecting hub 10 in which the connecting passage 22 is not formed and the retainer 40 so that the oil in the first piston chamber 24 is leak- .

The first piston (30) is disposed in close contact with the outer diameter of one side of the retainer (40) with respect to the wall (42) of the retainer (40). The first piston (30) is movable in the axial direction on the retainer (40) by the hydraulic pressure supplied to the first piston chamber (24). A sealing member 66 is interposed between the inner end of the first piston 30 and the retainer 40 to prevent the oil in the first piston chamber 24 from leaking into the space 62.

The second piston 50 includes a first cervical extension 52, an axial extension 54, a second cervical extension 56, and a pressing portion 58.

The first cervical extension 52 is disposed in close contact with the outer diameter of the other side of the retainer 40 with respect to the wall 42 of the retainer 40 and extends radially outward. A sealing member 67 is interposed between the inner end of the first radial extending portion 52 and the retainer 40 to prevent the oil in the second piston chamber 64 from leaking.

The axially extending portions 54 extend on both sides in the axial direction at the outer ends of the first radial extending portions 52. One end of the axial extension 54 is in contact with the first piston 30 and the other end of the axial extension 54 is in contact with the return spring 70. In Fig. 1, the disc spring is shown as the return spring 70, but it is not limited thereto and includes all means capable of exerting an elastic force such as a coil spring. A sealing member 69 is interposed between the inner peripheral surface of the axial extending portion 54 and the outer end of the wall 42 of the retainer 40 so that the oil in the second piston chamber 64 flows into the space 62 To prevent leakage. Further, a discharge passage 60 is formed in the axial extension portion 54. The discharge passage 60 is adapted to discharge the oil in the space 62 formed in the first piston 30, the axial extension portion 54 and the retainer 40. The space 62 and the first piston chamber 24 and the second piston chamber 64 are sealed by the sealing members 66 and 69 but the first piston chamber 24 and the second piston chamber 64 are closed during operation of the brake 1. [ Or the oil in the second piston chamber 64 may be infiltrated into the space 62. When the amount of the infiltrated oil is increased, the movement of the first and second pistons 30 and 50 may be interrupted. Therefore, the oil in the space 62 is discharged through the discharge passage 60.

The second cervical extension 56 extends radially outward at the end of the axially extending portion 54. The inner end of the second radial extension 56 is in close contact with the outer end of the first piston 30 and the outer end of the second radial extension 56 is in contact with the outer end of the connection hub 10 And is brought into close contact with the inner peripheral surface of the outer diameter portion 16. The outer end of the second radial extension portion 56 extends a certain distance in the axial direction in accordance with the inner circumferential surface shape of the outer diameter portion 16 of the connection hub 10. Therefore, the outer end of the second cervical extending portion 56 is movable in the axial direction in close contact with the inner circumferential surface of the outer diameter portion 16. A sealing member (68) is interposed between the outer end of the second radial extension (56) and the inner circumferential surface of the outer diameter portion (16) to prevent the oil in the first piston chamber (24) from leaking. The outer end of the first piston 30 is integrally coupled to the inner end of the second radial extension 56 by a fixing means. The fixing means includes welding, caulking, screws, rivets, , Splines, bonding with an adhesive, and the like. Thus, the first piston (30) is adapted to move with the second piston (50). On the other hand, when the outer end of the first piston 30 is fixed to the second radial extension 56 by the fixing means, the outer end of the first piston 30 and the extension of the second piston 50 A separate sealing means can be interposed in the tightly adhered portion 61. Examples of the sealing means include, but are not limited to, a liquid gasket and an anaerobic adhesive, and include all sealable means.

The pressing portion 58 extends radially outward from the end of the second radial extension portion 56. In the present embodiment, the outer end of the pressing portion 58 is spline coupled to the housing 90, but the present invention is not limited thereto.

The first piston chamber 24 is formed between the connection hub 10 and the first and second pistons 30 and 50 and the first piston chamber 24 is formed between the retainer 40 and the second piston 50. [ Two piston chambers 64 are formed. The oil is supplied to the first piston chamber 24 through the first oil passage 18 formed in the outer diameter portion 16 of the connection hub 10 and the oil supplied to the first piston chamber 24 is connected And is also supplied to the second piston chamber 64 through the oil passage 22 and the second oil passage 44 formed in the retainer 40. [

The return spring 70 contacts the other side portion of the axial extension portion 54 to provide a restoring force to the second piston 50. For this, the inner diameter portion of the return spring 70 is supported by the support means 72 mounted on the inner diameter portion 12 of the connection hub 10. As the support means 72, a snap ring, a two-part ring, or the like can be used.

The actuating plates 92 are disposed near the pressing portion 58 of the second piston 50. The actuating plates 92 are splined to the inner circumferential surface of the housing 90 so as to selectively move in the axial direction by the axial movement of the pressing portion 58. In the present specification, the housing 90 and the connection hub 10 are illustrated as separate members, but the present invention is not limited thereto. That is, the housing 90 and the connection hub 10 may be connected to each other or integrally formed.

The friction discs 82 are arranged alternately with the actuating plates 92 and are spline-coupled to the outer circumferential surface of the brake hub 80. Therefore, when the actuating plates 92 move to the right in the drawing by the urging portions 58 of the second piston 50, the actuating plates 92 and the friction discs 82 have frictional forces Respectively. As a result, the brake hub 80 is stopped.

Hereinafter, the operation of the brake 1 according to the first embodiment of the present invention will be described in detail.

When oil is supplied to the first piston chamber 24 through the supply passage 96 and the first oil passage 18 in the state where the brake 1 is not engaged with the first piston 30 and the second piston 30, Push the piston 50 to move it to the right in the drawing. The oil supplied to the first piston chamber 24 is also supplied to the second piston chamber 64 through the connecting passage 22 and the second oil passage 44, Push with additional force to move to the right in the drawing. At this time, since the first piston 30 and the second piston 50 are fixed, the hydraulic pressure acting on the first piston 30 and the hydraulic pressure acting on the second piston 50 are combined to form the second piston 50, By pushing the actuating plates 92 through the pushing portion 58 of the pushing member 58. As shown in Fig. Therefore, the brake 1 is engaged due to the frictional force between the operation plates 92 and the friction discs 82.

In this state, when the supply of oil to the first piston chamber 24 is stopped, the oil in the second piston chamber 64 flows through the connecting passage 22 and the second oil passage 44 into the first piston chamber 24 And finally the oil in the first piston chamber 24 is discharged through the supply passage 96 and the first oil passage 18. At this time, the restoring force of the return spring 70 pushes the second piston 50 together with the first piston 30 to the left in the drawing, and the actuating plates 92 and the friction discs 82 are released do.

2 is a cross-sectional view of a brake according to a second embodiment of the present invention.

As shown in FIG. 2, the brake according to the second embodiment of the present invention is very similar to the brake according to the first embodiment of the present invention, so that only differences will be described.

In the first embodiment of the present invention, the first radial extension 56 of the first piston 30 and the second radial piston 50 is fixed by various fixing means, but in the second embodiment of the present invention, The movement of the first piston (30) is constrained to the second radial extension (56) by the support means (25). That is, the rightward movement of the first piston 30 is restricted by the stepped portion 63 of the axially extending portion 54, and the leftward movement of the first piston 30 is restricted by the second radial extension portion 56 The first piston 30 and the second piston 50 move together as a whole. A snap ring or the like may be used as the support means 25.

In order to prevent the oil in the first piston chamber 24 from leaking, a sealing member 61 is provided in the close contact portion 61 between the inner end of the second radial extension portion 56 and the outer end of the first piston 30 69 are interposed.

In the second embodiment of the present invention, the first piston 30 and the second piston 50 are disassembled and reassembled without any action.

Since the structure and operation of the brake according to the second embodiment of the present invention are the same as those of the first piston 30 and the second piston 50, detailed description thereof will be omitted.

3 is a cross-sectional view of a brake according to a third embodiment of the present invention.

3, the brake 100 according to the third embodiment of the present invention includes a connection hub 110, a retainer 140, a first piston 130, a second piston 150, a return spring 170, actuation plates 192, and friction discs 182. The retainer 140, the first piston 130, the second piston 150, and the return spring 170 may be preassembled to form one piston module.

The connection hub 110 includes an inner diameter portion 112, an intermediate portion 114 extending radially outward from one end of the inner diameter portion 112, And an outer diameter portion 116 extending in the same direction as the outer diameter portion 116, and has a generally "C" shape as a whole. The connection hub 110 may be a transmission case or a housing.

The retainer 140 is disposed on the outer diameter portion 116 of the connection hub 110 and includes a wall 142 protruding radially inward. One end of the retainer 140 is supported by the intermediate portion 114 of the connection hub 110 and the other side of the retainer 140 is supported by the outer circumference 116 of the connection hub 110. [ And is supported by the member 146. The supporting member 146 may be a snap ring, a two-part ring, or the like.

The first connection channel 143 and the second connection channel 144 are formed in the retainer 140 so that the first piston chamber 124 and the second piston chamber 164 communicate with each other. Meanwhile, the first connection channel 143 may be formed on the inner circumferential surface of the outer diameter portion 116 of the connection hub 110.

A sealing member 175 is interposed between the retainer 140 and the inner peripheral surface of the outer diameter portion 116 to prevent oil from leaking from the first piston chamber 124 or the second piston chamber 164.

 The first piston 130 is disposed in close contact with the inner diameter of one side of the retainer 140 and is supported on the retainer 140 by the oil supplied to the first piston chamber 124 through the oil passage 105. [ And is movable in the axial direction. A sealing member 171 is interposed between the outer end of the first piston 130 and the inner circumferential surface of the retainer 140 to prevent the oil in the first piston chamber 124 from leaking into the space 107.

The second piston 150 includes an axially extending portion 152 and a radially extending portion 154 and a biasing portion 156.

The axial extending portion 152 is axially movably disposed on the inner diameter portion 112 of the connecting hub 110. The inner end of the wall 142 of the retainer 140 extends in the axial direction (152). A stepped portion 135 is formed at one side of the axial extension 152 and an inner end of the first piston 130 is closely attached to the stepped portion 135. The first piston (130) is restrained in the axial direction by the support means (158) mounted on the outer peripheral surface of the axial extension portion (152). That is, when the first piston 130 moves to the left in the drawing, the stepped portion 135 of the axial extending portion 152 restrains and the first piston 130 moves to the right in the drawing, So that the first piston 130 and the second piston 150 are moved together. A snap ring or the like may be used as the supporting means 158.

Therefore, in this case, the first piston 130 and the second piston 150 can be reassembled without any disassembly.

The engagement of the first piston 130 and the second piston 150 is not limited to the stepped portion 135 and the support means 158 but may be applied to various fixing means as in the first embodiment .

A discharge passage 160 is formed in the axial extending portion 152 to discharge the oil leaking into the space 107 formed by the axial extending portion 152, the retainer 140 and the first piston 130 .

A sealing member 172 is interposed between the inner circumferential surface of the axially extending portion 152 and the inner diameter portion 112 of the connection hub 110 to allow the oil in the first piston chamber 124 to flow into the space 107 To prevent leakage.

A sealing member 174 is interposed between the outer circumferential surface of the axial extension 152 and the inner end of the wall 142 to allow the oil in the second piston chamber 164 to leak into the space 107 prevent.

The radial extension 154 extends radially outward from the other end of the axially extending portion 152 and the outer end of the radial extension 154 is in close contact with the inner circumferential surface of the retainer 140, And is movable. A sealing member 176 is interposed between the outer end of the radial extending portion 154 and the inner circumferential surface of the retainer 140 to prevent the oil in the second piston chamber 164 from leaking.

A sealing member 173 is interposed between the inner diameter portion 112 of the connection hub 110 and the axially extending portion 152 of the second piston 150 so that the oil in the first piston chamber 124 is discharged to the outside Prevent leakage.

The pressing portion 156 protrudes in the axial direction from the intermediate portion of the radial extending portion 154 to the vicinity of the actuating plate 192. The pressing portion 156 may be integrally formed with the second piston 150 or may be separately manufactured and attached to the second piston 150 by welding or the like.

A first piston chamber 124 is formed between the first piston 130 and the connection hub 110 and a second piston chamber 124 is formed between the retainer 140 and the second piston 150. [ 164 are formed. When oil is supplied to the first piston chamber 124 through the oil passage 105 formed in the connection hub 110, the oil flows through the first and second connection oil passages 143 and 144 formed in the retainer 140 And is also supplied to the second piston chamber 164.

The return spring 170 is disposed in the space 107 formed by the axial extension 152, the retainer 140 and the first piston 130 to define the first piston chamber 124 or the second piston chamber 164 To the first piston (130). ≪ IMAGE > In this case, the second piston 150 moves to the right in the drawing together with the first piston 130 by the support means 158 for restricting the first piston 130 to the second piston 150. As the return spring 170, any kind of spring that provides an elastic force may be used, and as shown in FIG. 3, a plurality of springs may be used.

The actuation plates 192 are disposed near the pressing portion 156 of the second piston 150. The actuating plates 192 are splined to the inner circumferential surface of the outer diameter portion 116 of the connection hub 110 so as to selectively move axially by the axial movement of the pressing portion 156.

The friction discs 182 are disposed alternately with the actuating plates 192 and spline coupled to the outer circumferential surface of the brake hub 180. Therefore, when the actuating plates 192 are moved to the left in the drawing by the pressing portion 156 of the second piston 150, the actuating plates 192 and the friction discs 182 are urged by friction force Respectively. As a result, the brake hub 180 is stopped.

The structure of the brake 100 according to the third embodiment of the present invention is slightly different from that of the brake 1 according to the first embodiment of the present invention and the operation principle thereof is very similar, .

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And all changes to the scope that are deemed to be valid.

Claims (24)

A plurality of operating plates coupled to one member and friction discs coupled to the other member and alternately disposed with the plurality of operating plates, A brake for discs rubbing against each other and operatively connecting said one member and said another member,
A connecting hub including an inner diameter portion, an intermediate portion extending radially outward from one end of the inner diameter portion, and an outer diameter portion extending from the outer end of the intermediate portion in the same direction as the inner diameter portion;
A retainer disposed on an inner diameter portion of the connection hub, the retainer including a wall protruding radially outward;
A first piston disposed in close contact with an outer diameter of one side of the retainer and movable in an axial direction by an oil pressure supplied to the first piston chamber;
The first piston being in close contact with the outer end of the first piston and being axially moved together with the first piston by the hydraulic pressure supplied to the first piston chamber and the second piston chamber, A second piston adapted to press the plates and the friction discs; And
A return spring for applying a restoring force against the hydraulic pressure supplied to the first and second piston chambers to the second piston;
/ RTI >
Wherein the first piston, the second piston, and the retainer are preassembled to form one piston module, and the second piston is provided with a discharge passage for discharging the oil in the space formed by the first piston, the second piston, Is formed on the outer peripheral surface of the boss. The method according to claim 1,
The second piston
A first radial extension extending in the axial direction and being in close contact with the outer diameter of the other side of the retainer and being axially movable by hydraulic pressure supplied to the second piston chamber;
An axially extending portion extending axially at an outer end of the first cervical extension;
A second radial extension extending radially outward from an end of the axially extending portion and being in intimate contact with the inner circumferential surface of the outer diameter portion of the connecting hub and having an inner end in intimate contact with an outer end of the first piston; And
A pressing portion extending radially outward from an end of the second radial extension to a position of the actuating plate;
. 3. The method of claim 2,
Wherein the return spring is disposed on the other side of the axially extending portion and is disposed outside the piston module. The method according to claim 1,
Wherein the first piston is integrally coupled to the second piston by means of fastening means. 5. The method of claim 4,
Wherein said fastening means is caulking, press-fitting, splines, serrations, screws, rivets or bonding. 3. The method of claim 2,
Wherein a support means is mounted at an inner end of the second radial extension of the second piston and the first piston is supported by a step of the support means and the axially extending portion. The method according to claim 6,
And a sealing member is interposed between the outer end of the first piston and the inner end of the second radial extending portion. 8. The method according to claim 6 or 7,
Wherein the first piston and the second piston are capable of being reassembled after disassembly. 8. The method according to any one of claims 1 to 7,
Wherein an insertion groove is formed in an outer peripheral surface of an outer diameter portion of the connection hub, and a sealing member is inserted in the insertion groove. 10. The method of claim 9,
Wherein the sealing member has a supply passage formed therein and a first oil passage communicating with the first piston chamber and the supply passage is formed in the outer diameter portion of the connection hub. 8. The method according to any one of claims 1 to 7,
Wherein the connecting hub or the retainer is formed with a connecting passage communicating with the first piston chamber and the retainer is formed with a connecting oil passage and a second oil passage communicating with the second piston chamber. . 8. The method according to any one of claims 2 to 7,
Wherein a discharge passage for discharging oil in a space formed by the first piston, the retainer, and the axial extending portion is formed in the axial extending portion of the second piston. 8. The method according to any one of claims 1 to 7,
Wherein a support means is mounted on an inner diameter portion of the connection hub, and the support means supports the return spring. A plurality of operating plates coupled to one member and friction discs coupled to the other member and alternately disposed with the plurality of operating plates, A brake for discs rubbing against each other and operatively connecting said one member and said another member,
A connecting hub including an inner diameter portion, an intermediate portion extending radially outward from one end of the inner diameter portion, and an outer diameter portion extending from the outer end of the intermediate portion in the same direction as the inner diameter portion;
A retainer disposed on an outer diameter portion of the connection hub, the retainer including a wall protruding radially inward;
A first piston which is disposed in close contact with the inner diameter of one side of the retainer and is movable in the axial direction by an oil pressure supplied to the first piston chamber;
The first piston chamber and the second piston chamber are moved in the axial direction together with the first piston by the hydraulic pressure supplied to the first piston chamber and the second piston chamber so as to be in close contact with the inner diameter portion of the connecting hub, A second piston adapted to press the friction discs; And
A return spring for applying a restoring force against the hydraulic pressure supplied to the first and second piston chambers to the first piston;
/ RTI >
Wherein the first piston, the second piston, the retainer, and the return spring are assembled in advance to form one piston module, and the second piston is provided with a first piston, a second piston, And a discharge flow passage for discharging the fluid. 15. The method of claim 14,
The second piston
An axially extending portion disposed axially movably on an inner diameter portion of the connection hub;
A radial extension extending radially outward from an end of the axially extending portion, the radially extending portion having an outer circumferential surface in close contact with the inner diameter of the other side of the retainer; And
A pressing portion protruding axially from the radial extending portion to the position of the actuating plate;
. 15. The method of claim 14,
Wherein the return spring is disposed between the walls of the first piston and the retainer and is disposed in a space formed by the first piston, the second piston, and the retainer. 15. The method of claim 14,
Wherein the first piston is integrally coupled to the second piston by a fixing means. 18. The method of claim 17,
Wherein said fastening means is caulking, press-fitting, splines, serrations, screws, rivets or bonding. 16. The method of claim 15,
A support means is mounted on the axially extending portion of the second piston and the first piston is supported by a step formed in the support means and the axially extending portion and moves together with the second piston Features a brake. 20. The method of claim 19,
Wherein a sealing member is interposed between an inner end of the first piston and an outer diameter surface of the axially extending portion. 21. The method according to claim 19 or 20,
Wherein the first piston and the second piston are capable of being reassembled after disassembly. 21. The method according to any one of claims 14 to 20,
Wherein one side of the retainer is supported by a middle portion of the connecting hub and the other side of the retainer is supported by a supporting member mounted on an outer diameter portion of the connecting hub. 21. The method according to any one of claims 14 to 20,
Wherein the first piston chamber and the second piston chamber communicate with each other by a connection passage formed in an inner peripheral surface of the retainer or the connection hub. 21. The method according to any one of claims 15 to 20,
Wherein a discharge passage for discharging oil in the space formed by the axial extension, the wall and the first piston is formed in the axial extension of the second piston.

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