Sealing device

Abstract

To provide a sealing device which is excellent in assembly workability and achieves excellent design flexibility while inhibiting springs from twisting and moving during use.SOLUTION: A sealing device includes: an annular piston 100; a canceler seal 200 having a cancel plate 210; and springs 500 disposed between the annular piston 100 and the canceler seal 200. In the cancel plate 210, a cylindrical part 211, which is concentric with a rotation center axis of the sealing device, is provided at an intermediate position in a radial direction. Further, a guide member 230 which positions the springs 500 is fixed to an inner peripheral surface 211a of the cylindrical part 211 by fitting.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sealing device for use in an automatic transmission. [Background technology]

[0002] In an automatic transmission, a hydraulic actuator that drives a clutch for transmitting and releasing power is provided with a sealing device. A sealing device according to a conventional example will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a schematic cross-sectional view of a hydraulic actuator equipped with a sealing device according to a conventional example. Fig. 6 is a plan view of a cancel plate provided in the sealing device according to the conventional example.

[0003] The hydraulic actuator includes an annular cylinder 630 and an annular piston 610 that is provided so as to be capable of reciprocating in an annular space R0 provided in the annular cylinder 630. The annular piston 610 plays a role in switching between transmitting and releasing power by the clutch 640 by pressing or releasing the clutch plate as the annular piston 610 reciprocates in response to the hydraulic pressure in a hydraulic chamber R1 formed on one end side of the annular space R0. In addition, a canceller seal 620 having a cancel plate 621 is disposed on the opposite side of the annular piston 610 from the hydraulic chamber R1. The canceller seal 620 forms a cancel chamber R2 between the annular piston 610 and the annular piston 610, which generates hydraulic pressure that cancels out the centrifugal hydraulic pressure generated in the hydraulic chamber R1.

[0004] A plurality of springs (also called return springs) 650 are disposed between the annular piston 610 and the canceller seal 620. As a result, when the oil pressure in the oil pressure chamber R1 increases, the annular piston 610 moves toward the clutch 640 against the pressing force of the springs 650, pressing the clutch plate. When the oil pressure in the oil pressure chamber R1 decreases, the annular piston 610 moves in a direction away from the clutch 640 due to the pressing force of the springs 650, and the pressing force against the clutch plate is released.

[0005] In the sealing device configured as above, a technique is known in which a guide structure for the spring 650 is provided on the cancel plate 621 to improve the assembly workability of the sealing device and prevent the spring 650 from twisting or moving during use. That is, the cancel plate 621 is provided with a cylindrical portion 621a (see FIG. 5), and the inner circumferential surface 621b of this cylindrical portion 621b functions as a guide surface. More specifically, as shown in FIG. 6, a plurality of protruding portions protruding radially inward are provided at intervals in the circumferential direction on this inner circumferential surface 621b, so that a curved surface formed between adjacent protruding portions functions as a surface for holding the spring 650. Note that in FIG. 6, the position of the spring 650 is indicated by a dotted line. By adopting such a configuration, it becomes easy to adjust the position of the canceller seal 620 relative to the annular piston 610 and the spring 650 when assembling the sealing device, and the assembly workability is improved. In addition, it is possible to suppress the spring 650 from twisting or moving during use.

[0006] Here, the cancel plate 621 is obtained by processing a metal plate. Therefore, if the protrusion formed on the inner circumferential surface 621b is made to protrude too much, the plate thickness becomes too thin in parts or holes are formed, so there is a limit to the amount of protrusion. Therefore, there is a limit to the expansion of the area that holds the outer circumferential surface of the spring 650, and there is a risk that the positioning function of the spring 650 will be insufficient. Also, depending on the material of the cancel plate 621, it may be difficult to process the inner circumferential surface 621b into a desired shape. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-372073 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a sealing device which is easy to assemble, suppresses twisting or movement of a spring during use, and provides excellent design freedom. [Means for solving the problem]

[0009] The present invention employs the following means to solve the above problems.

[0010] That is, the sealing device of the present invention is an annular piston that is provided reciprocally movable within the annular space and that reciprocates in response to a hydraulic pressure in a hydraulic chamber formed at one end of the annular space to press or release a clutch plate, thereby switching between transmission and release of power by the clutch; a canceller seal having a cancel plate disposed on the opposite side of the hydraulic chamber across the annular piston, the canceller seal forming a cancel chamber between the annular piston and the canceller plate generating hydraulic pressure that cancels the centrifugal hydraulic pressure generated in the hydraulic chamber; A plurality of springs disposed between the annular piston and the canceller seal; A sealing device comprising: The cancel plate is provided with a cylindrical portion concentric with a rotation center axis of the sealing device at a radially intermediate position, A guide member for positioning the springs is fixed to the inner circumferential surface of the cylindrical portion only by fitting. At the same time, The guide member is configured as a cylindrical member having a plurality of protruding portions protruding radially inward at intervals in the circumferential direction, and a curved surface formed between adjacent protruding portions is used as a retaining surface for the spring. It is characterized by:

[0011] According to the present invention, the guide member for positioning the multiple springs is fixed by fitting to the inner circumferential surface of the cylindrical portion provided on the cancel plate, which allows for greater design freedom than when a guide surface for positioning the multiple springs is formed on the cancel plate by sheet metal processing.

[0013] The guide member is preferably made of a metal material or a resin material.

[0014] This makes it possible to increase the rigidity of the guide member and improve the function of holding the spring.

[0015] The annular piston may be provided with a plurality of fixing portions for fixing the plurality of springs, respectively. Effect of the Invention

[0016] As described above, according to the present invention, the assembly workability of the sealing device is excellent, and the degree of freedom in design can be increased while suppressing twisting and movement of the spring during use. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view of a hydraulic actuator equipped with a sealing device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of a cancel plate provided in the sealing device according to the embodiment of the present invention. [Diagram 3] FIG. 3 is a plan view of a guide member provided in the sealing device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a plan view showing a state in which a guide member is fitted into a cancel plate provided in the sealing device according to the embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic cross-sectional view of a hydraulic actuator equipped with a sealing device according to a conventional example. [Figure 6] FIG. 6 is a plan view of a cancel plate provided in a sealing device according to a conventional example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative positions, and the like of the components described in the embodiment are not intended to limit the scope of the present invention unless otherwise specified.

[0019] (Example) A sealing device according to an embodiment of the present invention will be described with reference to Figs. 1 to 4. Fig. 1 is a schematic cross-sectional view of a hydraulic actuator equipped with a sealing device according to an embodiment of the present invention. Fig. 1 shows a cross-sectional view of each member cut along a plane including a central axis of rotation in an annular sealing device. The right side in Fig. 1 is the central axis side. Fig. 2 is a plan view of a cancel plate provided in a sealing device according to an embodiment of the present invention, Fig. 3 is a plan view of a guide member provided in a sealing device according to an embodiment of the present invention, and Fig. 4 is a plan view showing a state in which a guide member is fitted into a cancel plate provided in a sealing device according to an embodiment of the present invention. The cross-sectional view of the cancel plate and the guide member in Fig. 1 corresponds to the AA cross-sectional view in Fig. 4. In the following description, the direction in which the central axis of rotation of an annular sealing device or the like extends is referred to as the "axial direction".

[0020] <Hydraulic actuator> With reference to FIG. 1, a hydraulic actuator including a sealing device according to the present embodiment will be described. The hydraulic actuator according to the present embodiment includes an annular cylinder 300 and an annular piston 100 provided in an annular space R0 provided in the annular cylinder 300 so as to be freely reciprocable. The annular piston 100 plays a role in switching between transmission and release of power by the clutch 400 by pressing or releasing the clutch plate as the annular piston 100 reciprocates in response to the hydraulic pressure in a hydraulic chamber R1 formed on one end side of the annular space R0. In addition, a canceller seal 200 having a cancel plate 210 is disposed on the opposite side of the hydraulic chamber R1 across the annular piston 100. The canceller seal 200 forms a cancel chamber R2 between the annular piston 100 and the canceller seal 200, which generates hydraulic pressure that cancels the centrifugal hydraulic pressure generated in the hydraulic chamber R1. In addition, a plurality of springs 500 are provided at intervals in the circumferential direction between the annular piston 100 and the canceller seal 200. The springs 500 are also called return springs. The annular piston 100, the canceller seal 200 and the spring 500 are the main components of the sealing device according to this embodiment.

[0021] The annular piston 100 includes a metal piston body 110, a first seal lip 120 provided on the inner peripheral surface of the piston body 110, and a second seal lip 130 provided on the outer peripheral surface of the piston body 110. The piston body 110 is made of a metal plate such as a steel plate. The piston body 110 is obtained by punching and press molding. The piston body 110 has a substantially flat plate portion 111, an inner cylinder portion 112 provided on the radial inside of the substantially flat plate portion 111, an inward flange portion 113 provided at the tip of the inner cylinder portion 112, and an outer cylinder portion 114 provided on the radial outside of the substantially flat plate portion 111. A first seal lip 120 is provided at the tip of the inward flange portion 113, and a second seal lip 130 is provided near the boundary between the substantially flat plate portion 111 and the outer cylinder portion 114. The first seal lip 120 and the second seal lip 130 are made of an elastic body such as rubber. For example, the first seal lip 120 and the second seal lip 130 can be integrally provided with the piston body 110 by insert molding using the piston body 110 as an insert part. In the illustrated example, the first seal lip 120 and the second seal lip 130 are connected together, but they may be provided separately without being connected together. The piston body 110 of the annular piston 100 is provided with a plurality of fixing portions 116 for fixing the plurality of springs 500, respectively.

[0022] The canceller seal 200 includes a metal cancel plate 210 and a third seal lip 220 provided on the outer circumferential surface side of the cancel plate 210. The cancel plate 210 is obtained by stamping and press-molding (sheet metal processing) a metal plate such as a steel plate. The inner circumferential end 212 of the cancel plate 210 is supported in a positioned state by a snap ring 313 fixed to a radially inner wall surface 310 of the annular cylinder 300. The third seal lip 220 is provided on the outer circumferential end 213 of the cancel plate 210. The third seal lip 220 is made of an elastic body such as rubber. For example, the third seal lip 220 can be provided integrally with the cancel plate 210 by insert molding using the cancel plate 210 as an insert part.

[0023] Further, a cylindrical portion 211 that is concentric with the rotational center axis of the sealing device is provided at a radially intermediate position of the cancel plate 210. In the sealing device according to the present embodiment, a guide member 230 that positions a plurality of springs 500 is fixed to an inner peripheral surface 211a of the cylindrical portion 211 by fitting.

[0024] The annular cylinder 300 is provided with a first oil passage 311 for introducing hydraulic pressure to the hydraulic chamber R1 and a second oil passage 312 for introducing hydraulic pressure to the cancel chamber R2. The first oil passage 311 and the second oil passage 312 are both provided to open to a wall surface 310 on the radially inner side of the annular cylinder 300.

[0025] The clutch 400 includes a plurality of drive plates 410 circumferentially engaged with a radially outer wall surface 320 of the annular cylinder 300 while being movable in the axial direction. The clutch 400 also includes a plurality of driven plates 420 circumferentially engaged with a clutch hub (not shown) provided on a driven shaft (not shown) while being movable in the axial direction. The plurality of drive plates 410 and the plurality of driven plates 420 are alternately arranged in the axial direction.

[0026] According to the hydraulic actuator configured as above, when the hydraulic pressure in the hydraulic chamber R1 increases due to the hydraulic pressure sent from the first oil passage 311, the annular piston 100 moves toward the clutch 400 against the pressing force of the spring 500. As a result, the tip 115 of the outer tubular portion 114 of the piston body 110 in the annular piston 100 presses the drive plate 410, which serves as a clutch plate, downward in FIG. 1. As a result, the drive plate 410 moves downward in FIG. 1, and the multiple drive plates 410 and the multiple driven plates 420 are frictionally engaged with each other. As a result, the clutch 400 is in a power transmitting state, and the driving torque of the drive shaft (not shown) is transmitted to the driven shaft (not shown) via the annular piston 100, the clutch 400, etc. Then, when the hydraulic pressure in the hydraulic chamber R1 decreases, the annular piston 100 moves toward the clutch 400. Since the piston 100 returns to its original position due to the pressing force of the spring 500, the annular piston 100 is released from the pressing state against the drive plate 410, and the frictional engagement state between the multiple drive plates 410 and the multiple driven plates 420 is also released. This also releases the transmission of power from the drive shaft to the driven shaft.

[0027] Here, the sealing device including the annular piston 100 and the annular cylinder 300, etc., rotate together with a drive shaft (not shown). Therefore, a centrifugal force of oil acts in the hydraulic chamber R1. Such centrifugal oil pressure may affect the operation of the annular piston 100. However, in this embodiment, oil that generates a centrifugal oil pressure equivalent to the above-mentioned centrifugal oil pressure is supplied from the second oil passage 312 to the cancel chamber R2. Therefore, since both the centrifugal oil pressure in the hydraulic chamber R1 and the centrifugal oil pressure in the cancel chamber R2 act on the annular piston 100, these oil pressures are offset. As a result, the centrifugal oil pressure does not affect the operation of the annular piston 100.

[0028] <Cancellation plate and guide member> In particular, the cancel plate 210 and the guide member 230 will be described in more detail with reference to Figs. 2 to 4. As described above, the guide member 230 is fixed to the inner peripheral surface 211a of the cylindrical portion 211 provided on the cancel plate 210 by fitting. The guide member 230 is configured as a cylindrical member in which a plurality of protruding portions 231 protruding radially inward are provided at intervals in the circumferential direction. In this embodiment, the plurality of protruding portions 231 are provided at equal intervals in the circumferential direction. In the guide member 230, the curved surface 232 formed between the adjacent protruding portions 231 is used as a holding surface for the spring 500. In Fig. 4, the arrangement position of the spring 500 is indicated by a dotted line. As shown in the figure, the curved surface 232 is formed so as to follow the outer peripheral surface of the spring 500. The guide member 230 plays a role of holding the spring 500, so it is preferable that the guide member 230 is made of a material with high rigidity. Therefore, it is preferable to adopt a metal material as the material of the guide member 230, but a resin material can also be adopted. In the guide member 230 according to this embodiment, the cross-sectional shape perpendicular to the central axis is configured to be the same no matter where it is cut.

[0029] <Advantages of the sealing device according to this embodiment> According to the sealing device of this embodiment, since the guide member 230 is provided, the position adjustment of the canceller seal 200 with respect to the annular piston 100 and the spring 500 is easy during assembly of the sealing device, and the assembly workability is improved. In addition, the spring 500 can be prevented from twisting or moving during use. The guide member 230 is fixed to the inner circumferential surface 211a of the cylindrical portion 211 provided on the cancel plate 210 by fitting. Therefore, compared to the case where a surface serving as a guide for positioning a plurality of springs is formed on the cancel plate by sheet metal processing, the design freedom can be increased. As a result, even if the material of the cancel plate 210 makes it difficult to perform sheet metal processing, the inner circumferential surface 211a of a desired shape can be formed by adopting a material that is easy to process as the material of the guide member 230. Therefore, the area for holding the outer circumferential surface of the spring 500 can be expanded, and the positioning function of the spring 500 can be improved.

[0030] In this way, the sealing device according to this embodiment has excellent assembly workability, and can increase design freedom while suppressing twisting or movement of the spring 500 during use. [Explanation of symbols]

[0031] 100 Annular piston 110 Piston body 111 Flat plate part 112 Inner cylinder 113 Inward flange part 114 Outer cylinder 115 Tip 116 Fixed part 200 Canceller seal 210 Cancellation Plate 211 Cylindrical part 211a Inner surface 212 Inner edge 213 Outer edge 230 Guide member 231 Protrusion 232 Curved Surface 300 Annular Cylinder 310 Wall 313 Snap ring 320 Wall 400 Clutch 410 Drive Plate 420 Driven Plate 500 Spring R0 Annular space R1 Hydraulic chamber R2 Cancellation Room

Claims

1. an annular piston that is provided reciprocally movable within the annular space and that reciprocates in response to a hydraulic pressure in a hydraulic chamber formed on one end side of the annular space to press or release a clutch plate, thereby switching between transmission and release of power by the clutch; a canceller seal having a cancel plate disposed on the opposite side of the hydraulic chamber across the annular piston, the canceller seal forming a cancel chamber between the annular piston and the canceller plate generating hydraulic pressure that cancels the centrifugal hydraulic pressure generated in the hydraulic chamber; A plurality of springs disposed between the annular piston and the canceller seal; A sealing device comprising: The cancel plate is provided with a cylindrical portion concentric with a rotation center axis of the sealing device at a radially intermediate position, a guide member for positioning the springs is fixed to the inner circumferential surface of the cylindrical portion only by fitting; The guide member is a cylindrical member having a plurality of protrusions protruding radially inward at intervals in the circumferential direction, and a curved surface formed between adjacent protrusions is used as a retaining surface for the spring.

2. The sealing device according to claim 1 , wherein the guide member is made of a metal material or a resin material.

3. 3. The sealing device according to claim 1, wherein the annular piston is provided with a plurality of fixing portions for fixing the plurality of springs, respectively.

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