JP7281980B2 - Sealing device for hydraulic actuator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic actuator sealing device, and more particularly to a hydraulic actuator sealing device having a piston movable by hydraulic pressure in an annular driving pressure chamber.

Hydraulic actuators include, for example, hydraulic clutches having annular pistons and used in automatic transmissions of vehicles such as automobiles. The hydraulic clutch engages the clutch by increasing the hydraulic pressure in the annular driving pressure chamber and pressing the annular piston against the clutch in the annular space, releasing the hydraulic pressure to the piston and returning the piston with the force of the spring. to disengage the clutch. In such a clutch piston mechanism, the oil in the drive pressure chamber is pressed against the piston by centrifugal force during driving, which affects the force of the spring that returns the piston when the clutch is disengaged, and the spring does not return the piston properly. Sometimes. For this reason, there is a conventional hydraulic clutch provided with a cancel plate and a cancel pressure chamber facing the drive pressure chamber via a piston. In such a hydraulic clutch, the centrifugal force also acts on the oil in the cancel pressure chamber, so that the pressing force of the oil in the drive pressure chamber due to the centrifugal force is offset.

The hydraulic clutch as described above is provided with a sealing device having an annular seal lip, and the piston hydraulic chamber is sealed by the seal lip provided on the outer peripheral side and the inner peripheral side of the piston. A seal lip provided on the outer peripheral side of the cancel plate serves to seal the outer peripheral side of the cancel pressure chamber (see, for example, Patent Document 1).

In the conventional hydraulic clutch as described above, hydraulic pressure acts on the seal lip in the drive pressure chamber and the cancel pressure chamber, and the seal lip is pressed against the contact surface of the housing. This makes it possible to maintain a higher hydraulic pressure in the drive pressure chamber and the cancel pressure chamber. Also, an oil film is formed between the seal lip and the contact surface of the housing, and this oil film reduces wear of the seal lip.

JP 2006-242311 A

2. Description of the Related Art In recent years, for example, automatic transmissions of automobiles have tended to be smaller and more powerful, and along with this trend, hydraulic pressure generated in a hydraulic pressure chamber of a piston for clutch engagement in a hydraulic clutch has also been increased. When the hydraulic pressure is increased, the contact surface of the housing presses the seal lip with high pressure, and the oil between the seal lip and the contact surface of the housing tends to be scraped out. When the oil between the seal lip and the contact surface of the housing is scraped off, the oil film between the seal lip and the contact surface of the housing becomes thin. When the oil film between the seal lip and the contact surface of the housing becomes thin, the sliding resistance between the seal lip and the contact surface of the housing increases, and the seal lip tends to wear out.

For this reason, conventional hydraulic clutches are required to have a configuration that suppresses thinning of the oil film between the seal lip and the contact surface of the housing even when the pressure acting on the seal lip becomes high. . As described above, a conventional sealing device for a hydraulic actuator is required to have a configuration capable of suppressing reduction of the oil film at the contact portion of the seal lip regardless of the magnitude of the acting hydraulic pressure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a sealing device for a hydraulic actuator capable of suppressing reduction of the oil film at the contact portion of the seal lip regardless of the magnitude of the acting hydraulic pressure. is to provide

To achieve the above objects, the present invention provides a sealing device for a hydraulic actuator, which includes a piston movable along an axis by hydraulic pressure in a drive pressure chamber, which is an annular space. an annular outer peripheral seal lip attached to the piston and formed of an elastic body for sealing the drive pressure chamber; and an annular seal lip attached to the piston. and an inner peripheral seal lip annular around the axis for sealing the driving pressure chamber on the inner peripheral side of the outer peripheral seal lip, the outer peripheral seal lip being annular around the axis. It has a main lip portion projecting to the outer peripheral side, an annular sub-lip portion projecting to the outer peripheral side around the axis, and an annular groove around the axis that is open on the outer peripheral side, and the main lip portion and the sub-lip portion are provided side by side, the main lip portion is provided on the driving pressure chamber side of the sub-lip portion, and the groove is formed between the main lip portion and the sub-lip portion. It is characterized by being

In one aspect of the hydraulic actuator sealing device according to the present invention, the main lip portion can be deformed toward the groove by hydraulic pressure in the drive pressure chamber.

In one aspect of the hydraulic actuator sealing device according to the present invention, the groove is inclined toward the driving pressure chamber side toward the outer peripheral side.

In one aspect of the hydraulic actuator sealing device according to the present invention, the sub-lip portion is inclined toward the driving pressure chamber side toward the outer peripheral side.

To achieve the above objects, the present invention provides a sealing device for a hydraulic actuator, which includes a piston movable along an axis by hydraulic pressure in a drive pressure chamber, which is an annular space. an annular cancel plate around the axis for forming a cancel pressure chamber, which is an annular space, on the opposite side of the piston and the driving pressure chamber in the hydraulic actuator; and a cancel pressure chamber attached to the cancel plate. A ring-shaped seal lip formed of an elastic material around the axis is provided for sealing. has an annular sub-lip portion protruding to the outer peripheral side, and an annular groove around the axis line that is open on the outer peripheral side, the main lip portion and the sub-lip portion are provided side by side, The main lip portion is provided on the cancel pressure chamber side of the sub-lip portion, and the groove is formed between the main lip portion and the sub-lip portion.

In one aspect of the hydraulic actuator sealing device according to the present invention, the main lip portion can be deformed toward the groove side by the hydraulic pressure in the cancel pressure chamber.

In one aspect of the hydraulic actuator sealing device according to the present invention, the groove is inclined toward the cancel pressure chamber side toward the outer peripheral side.

In one aspect of the hydraulic actuator sealing device according to the present invention, the sub-lip portion is inclined toward the cancel pressure chamber side toward the outer peripheral side.

According to the hydraulic actuator sealing device of the present invention, it is possible to suppress reduction of the oil film at the contact portion of the seal lip regardless of the magnitude of the acting hydraulic pressure.

1 shows a schematic configuration of a hydraulic clutch as a hydraulic actuator including a piston seal as a hydraulic actuator sealing device according to an embodiment of the present invention and a canceller seal as a hydraulic actuator sealing device according to an embodiment of the present invention; It is a partial cross-sectional view in a cross section along the axis. It is a sectional view in a section along an axis of a piston seal concerning an embodiment of the invention. FIG. 3 is a partial cross-sectional view showing a cross section on one side with respect to the axis of the piston seal shown in FIG. 2; 4 is a partially enlarged cross-sectional view showing an enlarged peripheral seal lip portion of the piston seal shown in FIG. 3; FIG. FIG. 4 is a cross-sectional view showing an enlarged portion of an outer peripheral seal lip of a piston seal in the hydraulic clutch in a state in which no driving oil pressure is generated in the driving pressure chamber; 6 is a cross-sectional view showing an enlarged portion of an outer peripheral seal lip in a state of being pressed by the driving hydraulic pressure in the driving pressure chamber in the use state shown in FIG. 5; FIG. FIG. 6 is a cross-sectional view showing an enlarged portion of an outer peripheral seal lip in the state of use shown in FIG. 5 in which the driving hydraulic pressure in the driving pressure chamber is released; FIG. 5 is a cross-sectional view showing an enlarged portion of the inner peripheral seal lip, showing a modified example of the inner peripheral seal lip in the piston seal according to the embodiment of the present invention; FIG. 2 is a cross-sectional view along the axis of the canceller seal according to the embodiment of the present invention; FIG. 10 is a partial cross-sectional view showing a cross section on one side of the canceller seal shown in FIG. 9 with respect to the axis x; 11 is a partially enlarged cross-sectional view showing an enlarged seal lip portion of the canceller seal shown in FIG. 10; FIG. FIG. 4 is an enlarged cross-sectional view showing a seal lip portion of a canceller seal in a hydraulic clutch in a state where no hydraulic pressure is generated in the cancel pressure chamber; 13 is an enlarged cross-sectional view showing a portion of a seal lip pressed by the hydraulic pressure in the cancel pressure chamber in the use state shown in FIG. 12; FIG. FIG. 13 is a cross-sectional view showing an enlarged portion of a seal lip in the state of use shown in FIG. 12 in which the hydraulic pressure in the cancel pressure chamber is released; FIG. 5 is an enlarged cross-sectional view showing a main lip portion for showing a modification of the outer peripheral seal lip of the piston seal according to the embodiment of the present invention; 16 is an enlarged sectional view showing the main lip portion shown in FIG. 15 in a state of being pressed by the driving hydraulic pressure in the driving pressure chamber; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 shows a hydraulic actuator as a hydraulic actuator comprising a piston seal 1 as a hydraulic actuator sealing device according to an embodiment of the present invention and a canceller seal 2 as a hydraulic actuator sealing device according to an embodiment of the present invention. FIG. 3 is a partial cross-sectional view along the axis x showing the schematic configuration of the clutch 100; Hereinafter, for convenience of explanation, in a direction orthogonal to the axis x direction (hereinafter also referred to as a radial direction), the direction away from the axis x (the direction of arrow a in FIG. 1) is defined as the outer peripheral side, and the direction approaching the axis x ( The side in the direction of arrow b in FIG. 1) is defined as the inner peripheral side. In addition, the arrow c (see FIG. 1) direction side in the axis x direction is the cut side, and the arrow d (see FIG. 1) direction side in the axis x direction is the connection side.

As shown in FIG. 1, the hydraulic clutch 100 includes a piston mechanism 3 having a piston seal 1 and a canceller seal 2, a clutch cylinder 110 forming an annular space, an annular clutch hub 120, the clutch cylinder 110 and the clutch. It has a multi-plate clutch 130 that connects or disconnects the hub 120 . The clutch cylinder 110 is connected to the driving side and is rotatable about the axis x by the power of the driving side. Further, the clutch hub 120 is connected to the driven side, and when the clutch 130 is engaged, the power of the clutch cylinder 110 is transmitted to the clutch hub 120 so that it can rotate around the axis x. The piston mechanism 3 acts on the clutch 130 to connect and disconnect the clutch 130 by moving the piston seal 1 in the direction of the axis x. The structure of the hydraulic clutch 100 will be specifically described below.

As shown in FIG. 1, the clutch cylinder 110 includes an inner peripheral cylindrical portion 111, which is a cylindrical portion having an axis x as a central axis or a substantially central axis, and an axial line x extending from the inner peripheral cylindrical portion 111 to the outer peripheral side. Alternatively, the disk portion 112, which is a disk-shaped portion approximately at the center, and the cylindrical portion with the axis x extending from the disk portion 112 to the connection side on the outer peripheral side of the inner peripheral cylindrical portion 111 as a central axis or approximately a central axis. and a certain outer cylindrical portion 113 . Clutch cylinder 110 also has an annular space 114 extending along axis x. The annular space 114 is a space surrounded by the outer peripheral surface 111 a of the inner peripheral cylindrical portion 111 , the connecting side surface 112 a of the disk portion 112 , and the inner peripheral surface 113 a of the outer peripheral cylindrical portion 113 .

The clutch 130, which is a multi-disc clutch, has a plurality of drive plates 131 and a plurality of driven plates 132. The drive plates 131 and the driven plates 132 are alternately arranged in the direction of the axis x with a space therebetween. there is The drive plate 131 is fixed to the inner peripheral surface 113a of the outer cylindrical portion 113 of the clutch cylinder 110 at the portion on the outer peripheral side. Driven plate 132 is fixed to clutch hub 120 at its inner peripheral portion. As will be described later, the drive plate 131 is pushed in the connection direction by the action of the piston mechanism 3 and pressed against the driven plate 132 in the direction of the axis x to connect with the driven plate 132 . As will be described later, when the piston mechanism 3 no longer presses the drive plate 131, the drive plate 131 moves away from the driven plate 132 in the direction of the axis x, and is disconnected from the driven plate 132. there is

The clutch hub 120 is an annular member around the axis x, and has a cylindrical portion 121 having the axis x as a central axis or a substantially central axis. A driven plate 132 of the above-described clutch 130 is fixed to the outer peripheral surface of the cylindrical portion 121 at the inner peripheral side end thereof.

A piston mechanism 3 is provided in the space 114 of the clutch cylinder 110, and the piston mechanism 3 forms an annular drive pressure chamber P1 and an annular cancel pressure chamber P2 in the space 114. As shown in FIG. As shown in FIG. 1, the piston seal 1 of the piston mechanism 3 is provided in the space 114 so as to be movable in the direction of the axis x, and the piston seal 1 forms a drive pressure chamber P1 on its cutting side. ing. As shown in FIG. 1, the canceller seal 2 faces the piston seal 1 from the connection side in the direction of the axis x, and forms a cancel pressure chamber P2, which is an annular space, between itself and the piston seal 1. there is The cancel pressure chamber P2 is provided in the space 114 on the opposite side of the piston seal 1 from the drive pressure chamber P1.

As will be described later, the piston seal 1 has a seal lip, and the seal lip is in contact with the surfaces of the clutch cylinder 110 forming a space 114 on the inner and outer peripheral sides, thereby forming a drive pressure chamber. P1 is sealed. Specifically, the seal lip of the piston seal 1 is in contact with the inner peripheral surface 113a of the outer cylindrical portion 113 of the clutch cylinder 110 on the outer peripheral side, and is in contact with the inner peripheral cylindrical portion 111 of the clutch cylinder 110 on the inner peripheral side. is in contact with the inner peripheral surface 111a of the . The piston seal 1 is formed so as to be able to contact the drive plate 131 positioned on the disengagement side of the clutch 130 from the disengagement side when moved to the connection side in the direction of the axis x.

As will be described later, the canceller seal 2 has a seal lip, and the seal lip is in contact with the piston seal 1 on the outer peripheral side, thereby sealing the outer peripheral side of the cancel pressure chamber P2. ing. Specifically, the seal lip of the canceller seal 2 contacts the portion of the piston seal 1 contacting the clutch 130 on the outer peripheral side from the inner peripheral side. The canceller seal 2 is supported by the inner cylindrical portion 111 of the clutch cylinder 110 via a snap ring 141 and rotates together with the clutch cylinder 110 .

The piston mechanism 3 has a return spring 140, which is a spring. The return spring 140 is provided in the cancel pressure chamber P2, is sandwiched between the piston seal 1 and the canceller seal 2, and extends along the axis x. It biases the piston seal 1 towards the cut side in direction.

Clutch cylinder 110 is formed with drive oil hole 115, which is a passage for supplying hydraulic oil to drive pressure chamber P1 and for discharging hydraulic oil from drive pressure chamber P1. The hydraulic oil is oil for controlling the hydraulic clutch 100, and is, for example, ATF (Automatic Transmission Fluid). The drive oil hole 115 is open to the drive pressure chamber P1 on the outer peripheral surface 111a of the inner cylindrical portion 111, and enables communication between the drive pressure chamber P1 and a hydraulic oil supply source (not shown). Further, the clutch cylinder 110 is formed with a cancel oil hole 116, which is a passage for supplying hydraulic fluid to the cancel pressure chamber P2 and discharging hydraulic fluid from the cancel pressure chamber P2. The cancel oil hole 116 opens into the cancel pressure chamber P2 on the outer peripheral surface 111a of the inner cylindrical portion 111, and enables communication between a supply source (not shown) of hydraulic oil and the cancel pressure chamber P2.

In the hydraulic clutch 100, hydraulic oil (driving oil pressure) is generated in the driving pressure chamber P1 by supplying hydraulic oil to the driving pressure chamber P1 through the driving oil hole 115. As shown in FIG. This driving oil pressure causes the piston seal 1 to move toward the connection side against the biasing force of the return spring 140, and the piston seal 1 contacts the drive plate 131 of the clutch 130 and pushes the drive plate 131 toward the connection side. As a result, the drive plates 131 of the clutch 130, that is, the clutch cylinder 110, are moved toward the connection side, and each drive plate 131 contacts and presses the corresponding driven plate 132. As shown in FIG. As a result, clutch 130 is brought into a connected state, and the power of clutch cylinder 110 is transmitted to clutch hub 120 via clutch 130 .

When the hydraulic fluid in the driving pressure chamber P1 is discharged through the driving oil hole 115 from this connected state of the clutch 130, the driving hydraulic pressure in the driving pressure chamber P1 is released and reduced, and the biasing force of the return spring 140 is released. The driving hydraulic pressure is overcome, the piston seal 1 is moved to the disengaged side by the biasing force of the return spring 140, the drive plate 131 is separated from the driven plate 132, and the clutch 130 is disengaged.

When the clutch cylinder 110 rotates, a centrifugal force is applied to the hydraulic fluid in the drive pressure chamber P1, and this centrifugal force acts on the piston seal 1, moving the piston seal 1, and unintentionally operating the clutch 130. I can put it away. Therefore, by supplying hydraulic fluid into the cancel pressure chamber P2 through the cancel oil hole 116, centrifugal force acts on the hydraulic fluid in the cancel pressure chamber P2 in the same manner as the hydraulic fluid in the drive pressure chamber P1. make sure to As a result, the centrifugal force acting on the hydraulic fluid in the cancel pressure chamber P2 offsets the centrifugal force acting on the hydraulic fluid in the drive pressure chamber P1, thereby preventing unintended operation of the clutch 130. FIG.

The clutch cylinder 110, the clutch hub 120, the clutch 130, the return spring 140, and the snap ring 141 of the hydraulic clutch 100 can have various forms, and can have, for example, a conventional hydraulic clutch structure. A detailed description of these configurations of the hydraulic clutch 100 is omitted, and a piston seal 1 and a canceller seal 2 according to the embodiment of the present invention will be described in detail below.

FIG. 2 is a cross-sectional view of the piston seal 1 according to the embodiment of the present invention along the axis x, and FIG. 3 is a portion showing a cross section on one side of the piston seal 1 shown in FIG. 2 with respect to the axis x. It is a sectional view. As shown in FIGS. 2 and 3, the piston seal 1 includes an annular piston 10 around an axis x and an axis x formed of an elastic material for sealing a drive pressure chamber P1 attached to the piston 10. An outer peripheral seal lip 20 annular around the periphery, and an inner peripheral seal lip 30 annular around the axis x for sealing the drive pressure chamber P1 on the inner peripheral side of the outer peripheral seal lip 20 attached to the piston 10 It has The outer peripheral seal lip 20 includes a main lip portion 21 which is annular and protrudes outward around the axis x, a sub-lip portion 22 which is annular and protrudes outward around the axis x, and is open around the axis x. and an annular groove 23 . The main lip portion 21 and the sub-lip portion 22 are provided side by side, and the main lip portion 21 is provided on the drive pressure chamber side of the sub-lip portion 22. formed between The configuration of the piston seal 1 will be specifically described below.

The piston 10 is an annular member made of metal and centered or substantially centered on the axis x. As shown in FIGS. The pressure receiving portion 11 is an annular portion centered or substantially centered on the axis x, and is a portion of the hydraulic clutch 100 (see FIG. 1) that receives the driving hydraulic pressure in the driving pressure chamber P1. The clutch pressing portion 12 is an annular portion centered or substantially centered on the axis x. , and presses the drive plate 131 toward the connection side. The clutch pressing portion 12 extends from the outer peripheral end of the pressure receiving portion 11 toward the connecting side. Piston 10 can take a variety of forms, for example, it can be similar to a conventional piston.

The outer peripheral seal lip 20 and the inner peripheral seal lip 30 are, for example, part of the elastic body portion 4 formed of an elastic body attached to a surface (pressure receiving surface 11a) facing the cut side of the pressure receiving portion 11 of the piston 10. are integrally formed as The outer peripheral seal lip 20 and the inner peripheral seal lip 30 may be formed separately.

As shown in FIGS. 2 and 3, the outer peripheral seal lip 20 is an annular or substantially annular portion centered or substantially centered on the axis x that protrudes outward from the outer peripheral portion of the pressure receiving portion 11 . The outer peripheral seal lip 20 is formed so as to come into contact with the inner peripheral surface 113a of the outer peripheral cylindrical portion 113 of the clutch cylinder 110 in the hydraulic clutch 100 (see FIG. 1). Further, in the hydraulic clutch 100, the outer peripheral seal lip 20 is formed so as to slide on the inner peripheral surface 113a of the outer peripheral cylindrical portion 113 when the piston seal 1 moves in the direction of the axis x. A detailed description of the outer peripheral seal lip 20 will be given later.

As shown in FIGS. 2 and 3, the inner peripheral seal lip 30 is an annular or substantially annular portion centered or substantially centered on an axis x projecting from the inner peripheral side portion of the pressure receiving portion 11 to the inner peripheral side. be. The inner peripheral seal lip 30 is formed so as to come into contact with the outer peripheral surface 111a of the inner peripheral cylindrical portion 111 of the clutch cylinder 110 in the hydraulic clutch 100 (see FIG. 1). In addition, the inner peripheral seal lip 30 is formed so as to slide on the outer peripheral surface 111a of the inner peripheral tubular portion 111 when the piston seal 1 moves in the direction of the axis x in the hydraulic clutch 100 .

The piston 10 is made of metal as described above, and the metal material of the piston 10 includes stainless steel, SPCC (cold rolled steel), etc., mainly SPFH (hot rolled steel) and SAPH (hot rolled steel). ). The piston seal 10 is manufactured, for example, from a metal plate by pressing or forging.

As described above, the elastic body portion 4 is an elastic body that covers the pressure receiving surface 11a of the pressure receiving portion 11 of the piston 10, and the elastic material of the elastic body portion 4 is, for example, a rubber-like elastic material. As the rubber-like elastic material of the elastic body part 4, for example, nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), fluororubber (FKM), silicone rubber, styrene-butadiene rubber (SBR ) and other synthetic rubbers are used.

FIG. 4 is a partially enlarged cross-sectional view showing an enlarged peripheral seal lip 20 portion of the piston seal 1 shown in FIG. As described above, the outer peripheral seal lip 20 has the main lip portion 21 , the sub-lip portion 22 , and the groove 23 formed between the main lip portion 21 and the sub-lip portion 22 .

The main lip portion 21 is a portion that protrudes toward the outer peripheral side of an annular or substantially annular shape centered or substantially centered on the axis x. Specifically, as shown in FIG. It protrudes from the pressure-receiving surface 11a while being inclined toward the cutting side (arrow c direction) toward the outer peripheral side (arrow a direction). In the hydraulic clutch 100 (see FIG. 1), the main lip portion 21 is formed so as to slidably contact the inner peripheral surface 113a of the outer cylindrical portion 113 of the clutch cylinder 110 . For example, the main lip portion 21 is formed such that the corner portion 24a on the outer peripheral side (in the direction of arrow a) of the tip portion 24 comes into slidable contact with the inner peripheral surface 113a of the outer cylindrical portion 113 of the clutch cylinder 110. there is

Further, the main lip portion 21 can be deformed toward the groove 23 by the driving hydraulic pressure in the driving pressure chamber P1 in the hydraulic clutch 100. As shown in FIG. Specifically, the main lip portion 21 is deformable so that the cross-sectional area of the groove 23 is reduced when the hydraulic clutch 100 receives the drive pressure of the hydraulic oil in the drive pressure chamber P1. It is preferable that the main lip portion 21 is formed in such a shape that the area of the opening 23a of the groove 23 does not decrease when the main lip portion 21 is deformed. For example, as shown in FIG. 4, the side surface 25 facing the cutting side (drive pressure chamber P1 side) of the main lip portion 21 has a concave portion 25a that is concave in the thickness direction of the main lip portion 21 at the root side portion. formed. Since the thickness of the root side portion of the main lip portion 21 in the thickness direction is reduced by the recess 25a, the driving hydraulic pressure of the driving pressure chamber P1 is applied to the outer peripheral surface 25 of the main lip portion 21 in the hydraulic clutch 100. At this time, the main lip portion 21 tends to bend from the root side portion such that the tip portion 24 faces the inner peripheral side. The shape of the main lip portion 21 that can be deformed so that the cross-sectional area of the groove 23 decreases when the main lip portion 21 receives the driving hydraulic pressure in the driving pressure chamber P1 in the hydraulic clutch 100 is another shape. good too. The thickness direction of the main lip portion 21 is a direction perpendicular to the direction in which the main lip portion 21 protrudes (projection direction).

The sub-lip portion 22 is a portion that protrudes toward the outer peripheral side of an annular or substantially annular shape centered or substantially centered on the axis x. Specifically, as shown in FIG. It protrudes from the surface 11a while being inclined toward the cutting side (arrow c direction) toward the outer peripheral side (arrow a direction). In the hydraulic clutch 100 (see FIG. 1), the sub-lip portion 22 is formed so as to slidably contact the inner peripheral surface 113a of the outer cylindrical portion 113 of the clutch cylinder 110 . For example, the sub-lip portion 22 is formed such that the outer peripheral portion (outer peripheral portion 26 a ) of the tip end portion 26 comes into slidable contact with the inner peripheral surface 113 a of the outer cylindrical portion 113 of the clutch cylinder 110 .

The sub-lip portion 22 does not protrude parallel to the main lip portion 21, as shown in FIG. More specifically, the projecting direction of the sub-lip portion 22 is not parallel to the projecting direction of the main lip portion 21, but is inclined toward the cutting side with respect to the projecting direction of the main lip portion 21. As shown in FIG. The sub-lip portion 22 may protrude in parallel with the main lip portion 21 and may not be inclined toward the cutting side from the protruding direction of the main lip portion 21 . Further, the sub-lip portion 22 is formed, for example, so as to taper toward the distal end portion 26 .

The sub-lip portion 22 is spaced from the main lip portion 21 on the connection side in the thickness direction of the main lip portion 21 . is formed in As shown in FIG. 4, the groove 23 has an opening 23a on the outer peripheral side and is open at the opening 23a. For example, the groove 23 is inclined toward the driving pressure chamber P1 side (cutting side) toward the outer peripheral side.

Next, the action of the piston seal 1 having the above configuration will be explained. FIG. 5 is a cross-sectional view showing an enlarged portion of the outer peripheral seal lip 20 of the piston seal 1 in the hydraulic clutch 100 in a state where no driving hydraulic pressure is generated in the driving pressure chamber P1. As shown in FIG. 5 , when the piston seal 1 used in the hydraulic clutch 100 is used, the corner portion 24 a of the main lip portion 21 and the outer peripheral portion 26 a of the sub lip portion 22 are positioned inside the outer peripheral tubular portion 113 of the clutch cylinder 110 . It is in slidable contact with the peripheral surface 113a. Thus, the driving pressure chamber P1 is sealed.

Further, in the operating state, the hydraulic oil supplied in the driving pressure chamber P1 intervenes in the sliding portion between the corner portion 24a of the main lip portion 21 and the inner peripheral surface 113a of the clutch cylinder 110, and the oil film is formed. An oil film is formed between the outer peripheral portion 26a of the sub-lip portion 22 and the inner peripheral surface 113a of the clutch cylinder 110 at the sliding portion. In addition, hydraulic oil is accumulated in the grooves 23 . As a result, the main lip portion 21 and the sub-lip portion 22 smoothly slide on the inner peripheral surface 113a of the clutch cylinder 110 as the piston seal 1 moves in the direction of the axis x.

When driving hydraulic pressure is generated in the driving pressure chamber P1, the main lip portion 21 is pressed against the inner peripheral surface 113a of the clutch cylinder 110 by this driving hydraulic pressure. As the driving oil pressure increases, the main lip portion 21 is pressed against the inner peripheral surface 113a of the clutch cylinder 110 more strongly. For this reason, when the driving oil pressure increases, the oil film intervening in the sliding portion of the main lip portion 21 is more strongly crushed or scraped off, the oil film becomes thinner, and the main lip portion 21 tends to wear out. Further, since the main lip portion 21 is pressed against the inner peripheral surface 113a of the clutch cylinder 110 more strongly, it becomes difficult for hydraulic oil to be supplied from the driving pressure chamber P1 to the sliding portion of the sub-lip portion 22, and the sub-lip portion 22 is easily worn. Become.

On the other hand, in the piston seal 1 according to the embodiment of the present invention, as shown in FIG. 6, a driving oil pressure is generated in the driving pressure chamber P1, and the piston seal 1 is pushed by the hydraulic oil and moves in the connecting direction. When moved, the outer peripheral seal lip 20 also slides in the connecting direction, and hydraulic oil accumulated in the groove 23 flows out from the groove 23 . Hydraulic oil flowing out from the groove 23 is supplied to the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22 . As a result, the thickness of the oil film formed on the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22 can be maintained. Therefore, even if the driving hydraulic pressure increases, the wear of the main lip portion 21 and the sub-lip portion 22 can be suppressed.

In particular, when the driving oil pressure in the driving pressure chamber P1 increases, the main lip portion 21 is strongly pressed against the groove 23 side. Therefore, the main lip portion 21 is deformed toward the groove 23 and the cross-sectional area of the groove 23 is reduced. As a result, the working oil accumulated in the groove 23 can be forcibly flowed out from the groove 23 . Therefore, the higher the driving oil pressure in the driving pressure chamber P1, the more hydraulic oil in the groove 23 can be supplied to the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22. And the wear of the sub-lip portion 22 can be further suppressed.

As described above, the main lip portion 21 is deformable so that the cross-sectional area of the groove 23 is reduced by the driving hydraulic pressure in the driving pressure chamber P1. Therefore, more hydraulic oil in the groove 23 can be supplied to the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22, thereby further suppressing wear of the main lip portion 21 and the sub-lip portion 22. be able to. In terms of supplying the hydraulic oil in the groove 23 to the sliding portion in this manner, the main lip portion 21 can be deformed into a shape such that the area of the opening 23a of the groove 23 is not reduced by the drive hydraulic pressure, as described above. is preferably formed.

On the other hand, as shown in FIG. 7, when the hydraulic fluid is discharged from the driving pressure chamber P1 and the driving pressure pressing the main lip portion 21 is released, the piston seal 1 moves toward the cutting side. As a result, the outer peripheral seal lip 20 and the sub-lip portion 22 slide to the cutting side. As a result, the sub-lip portion 22 collects hydraulic oil in the groove 23 . Further, the pressing force of the driving hydraulic pressure that presses the main lip portion 21 and the sub-lip portion 22 against the inner peripheral surface 113a of the clutch cylinder 110 is released. As a result, the hydraulic oil moves into the groove 23 through the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22 .

As described above, the main lip portion 21 is deformed toward the groove 23 by the driving hydraulic pressure in the driving pressure chamber P1, and the cross-sectional area of the groove 23 is reduced. As it goes on, the main lip portion 21 returns to its original shape, and the cross-sectional area of the groove 23 expands so as to return to its original size. By restoring the cross-sectional area of the groove 23, the hydraulic oil can be sucked into the groove 23 through the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22 when the driving oil pressure is released. This suction can thicken the oil film on the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22 .

Further, the sub-lip portion 22 is inclined toward the outer peripheral side toward the cutting side as described above. In other words, the sub-lip portion 22 is in contact with the inner peripheral surface 113a of the clutch cylinder 110 at a shallow angle of inclination. Therefore, by sliding the sub-lip portion 22 toward the cutting side, the working oil can be easily collected in the groove 23 . Thus, in order to make it easier to collect hydraulic oil in the groove 23, it is preferable that the sub-lip portion 22 is formed so as to be inclined toward the outer peripheral side toward the cutting side.

In addition, as described above, the groove 23 is inclined toward the cutting side toward the outer peripheral side. That is, the groove 23 has a shallow inclination angle with respect to the inner peripheral surface 113 a of the clutch cylinder 110 . Therefore, by sliding the outer peripheral seal lip 20 toward the cutting side, it is possible to easily introduce the working oil into the groove 23 . In this way, in order to facilitate the introduction of hydraulic oil into the groove 23, the groove 23 is preferably formed so as to be inclined toward the outer peripheral side from the cutting side. Moreover, if the groove 23 is inclined toward the cutting side toward the outer peripheral side, the working oil in the groove 23 can be easily discharged from the opening 23a.

Thus, when the driving oil pressure in the driving pressure chamber P1 is released, the outer peripheral seal lip 20 can guide the working oil into the groove 23, and the main lip portion 21 is moved by the driving oil pressure in the driving pressure chamber P1. Even if hydraulic oil is discharged from the groove 23 by being pressed, the hydraulic oil can be stored in the groove 23 again. Further, as the outer peripheral seal lip 20 slides, the working oil can be guided into the groove 23, and even if the working oil is discharged from the groove 23, the working oil can be stored in the groove 23 again. In this process, the oil film on the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22, which has been thinned or lost, can be thickened or regenerated. Therefore, even if the driving hydraulic pressure in the driving pressure chamber P1 is repeatedly generated and released, the outer peripheral seal lip 20 repeats the discharge of the hydraulic oil in the groove 23 and the supply of the hydraulic oil in the groove 23. The oil film on the sliding portion of the main lip portion 21 and the sliding portion of the sub-lip portion 22 can be maintained, and wear of the main lip portion 21 and the sub-lip portion 22 can be further suppressed. Even when a high driving oil pressure is applied to the main lip portion 21, the deformation of the main lip portion 21 and the release of the driving oil pressure allow hydraulic oil to be supplied into the grooves 23. Therefore, regardless of the magnitude of the driving oil pressure, The above-mentioned effect is obtained.

As described above, according to the piston seal 1 according to the embodiment of the present invention, it is possible to suppress the reduction of the oil film at the contact portion of the outer peripheral seal lip 20 regardless of the magnitude of the acting driving hydraulic pressure.

In the piston seal 1 described above, the inner peripheral seal lip 30 is a conventional seal lip protruding to the outer peripheral side, but the inner peripheral seal lip 30 may have the same configuration as the outer peripheral seal lip. In this case, as shown in FIG. 8, the inner peripheral seal lip 30 according to this modification includes a main lip portion 31 annularly projecting inwardly around the axis x, and It has an annular sub-lip portion 32 protruding toward the inner periphery, and an annular groove 33 around the axis x that is open on the inner periphery. The main lip portion 31 and the sub-lip portion 32 are provided side by side, the main lip portion 31 is provided on the drive pressure chamber side of the sub-lip portion 32, and the groove 33 is formed between the main lip portion 31 and the sub-lip portion 32. formed between

The main lip portion 31, the sub-lip portion 32, and the groove 33 of the inner peripheral seal lip 30 according to this modification have the same forms as the main lip portion 21, the sub-lip portion 22, and the groove 23 of the above-described outer peripheral seal lip 20, respectively. have. Hereinafter, the configuration of the inner peripheral seal lip 30 according to the modification will be specifically described.

As shown in FIG. 8, the main lip portion 31 is a portion that protrudes toward the inner peripheral side of an annular or substantially annular shape centered or substantially centered on the axis x. It protrudes from the end on the inner peripheral side of 11 toward the inner peripheral side (direction of arrow b) while being inclined toward the cutting side (direction of arrow c). In the hydraulic clutch 100 (see FIG. 1), the main lip portion 31 is formed so as to slidably contact the outer peripheral surface 111a of the inner peripheral tubular portion 111 of the clutch cylinder 110 . For example, the main lip portion 31 is formed such that the corner portion 34a on the inner peripheral side (in the direction of arrow b) of the tip end portion 34 comes into slidable contact with the outer peripheral surface 111a of the inner peripheral cylindrical portion 111 of the clutch cylinder 110. ing.

Further, the main lip portion 31 can be deformed toward the groove 33 by the driving hydraulic pressure in the driving pressure chamber P1 in the hydraulic clutch 100. As shown in FIG. Specifically, the main lip portion 31 is deformable such that the cross-sectional area of the groove 33 is reduced when the hydraulic clutch 100 receives the drive pressure of the hydraulic oil in the drive pressure chamber P1. It is preferable that the main lip portion 31 is formed in such a shape that the area of the opening 33a of the groove 33 does not decrease when the main lip portion 31 is deformed. For example, as shown in FIG. 8, the side surface 35 of the main lip portion 31 facing the cutting side (drive pressure chamber P1 side) has a concave portion 35a that is concave in the thickness direction of the main lip portion 31 at the root side portion. formed. Due to this recess 35a, the thickness of the main lip portion 31 on the root side is reduced in the thickness direction, so that the driving hydraulic pressure of the driving pressure chamber P1 is applied to the outer peripheral surface 35 of the main lip portion 31 in the hydraulic clutch 100. At this time, the main lip portion 31 tends to bend from the root side portion so that the tip portion 34 faces the inner peripheral side. The shape of the main lip portion 31 that can be deformed so that the cross-sectional area of the groove 33 decreases when the main lip portion 31 receives the driving hydraulic pressure in the driving pressure chamber P1 in the hydraulic clutch 100 is another shape. good too.

The sub-lip portion 32 is a circular or substantially circular ring-shaped portion centered or substantially centered on the axis x and protruding toward the inner peripheral side. It protrudes at an angle toward the cutting side (arrow c direction) toward the inner peripheral side (arrow b direction) from the bottom. In the hydraulic clutch 100 (see FIG. 1), the sub-lip portion 32 is formed so as to slidably contact the outer peripheral surface 111a of the inner peripheral tubular portion 111 of the clutch cylinder 110 . For example, the sub lip portion 32 is formed such that the inner peripheral portion (inner peripheral portion 36 a ) of the tip end portion 36 comes into slidable contact with the outer peripheral surface 111 a of the inner peripheral tubular portion 111 of the clutch cylinder 110 .

The sub-lip portion 32 does not protrude parallel to the main lip portion 31, as shown in FIG. More specifically, the projecting direction of the sub lip portion 32 is not parallel to the projecting direction of the main lip portion 31 but is inclined toward the cutting side with respect to the projecting direction of the main lip portion 31 . The sub-lip portion 32 may protrude in parallel with the main lip portion 31 and may not be inclined toward the cutting side from the protruding direction of the main lip portion 31 . Further, the sub-lip portion 32 is formed, for example, so as to taper toward the distal end portion 36 .

The sub-lip portion 32 is spaced from the main lip portion 31 on the connecting side in the thickness direction of the main lip portion 31 . is formed in As shown in FIG. 8, the groove 33 has an opening 33a on the outer peripheral side and is open at the opening 33a. For example, the groove 33 is inclined toward the drive pressure chamber P1 side (cutting side) toward the inner peripheral side.

As described above, the inner peripheral seal lip 30 according to the modification has the main lip portion 31 , the sub-lip portion 32 and the groove 33 like the outer peripheral seal lip 20 . Therefore, the inner peripheral seal lip 30 according to the modified example acts in the same manner as the outer peripheral seal lip 20 described above in the hydraulic clutch 100, and even if the driving hydraulic pressure in the driving pressure chamber P1 is repeatedly generated and released, the groove 33 remains closed. By repeating the discharge of hydraulic oil inside and the supply of hydraulic oil to the groove 33, it is possible to maintain the oil film on the sliding portion of the main lip portion 31 and the sliding portion of the sub-lip portion 32. Wear of 31 and sub lip portion 32 can be further suppressed. Further, even when a high driving oil pressure is applied to the main lip portion 31, the deformation of the main lip portion 31 and the release of the driving oil pressure allow hydraulic oil to be supplied into the grooves 33. Regardless, the above effects are achieved.

As described above, according to the piston seal 1 having the inner peripheral seal lip 30 according to the modified example, regardless of the magnitude of the acting driving hydraulic pressure, the oil film at the contact portion between the outer peripheral seal lip 20 and the inner peripheral seal lip can be reduced. can be suppressed.

Next, a canceller seal 2 according to an embodiment of the present invention will be described. 9 is a cross-sectional view of the canceller seal 2 according to the embodiment of the present invention taken along the axis x, and FIG. 10 is a portion showing a cross section on one side of the canceller seal 2 shown in FIG. 9 with respect to the axis x. It is a sectional view. As shown in FIGS. 9 and 10, the canceller seal 2 is formed of an annular cancel plate 40 around the axis x and an elastic body attached to the cancel plate 40 for sealing the cancel pressure chamber P2. An annular seal lip 50 is provided around the axis x. As described above, the cancel plate 40 forms the cancel pressure chamber P2, which is an annular space, on the opposite side of the hydraulic actuator 100 from the piston seal 1 and the drive pressure chamber P1. The seal lip 50 includes a main lip portion 51 annularly projecting to the outer peripheral side around the axis x, a sub-lip portion 52 annularly projecting to the outer peripheral side around the axis x, and an annular ring around the axis x opened on the outer peripheral side. and a groove 53 of . The main lip portion 51 and the sub-lip portion 52 are provided side by side, the main lip portion 51 is provided on the cancel pressure chamber side of the sub-lip portion 52, and the groove 53 is formed between the main lip portion 21 and the sub-lip portion 22. formed between The configuration of the canceller seal 2 will be specifically described below.

As shown in FIGS. 9 and 10, the cancel plate 40 is an annular member made of metal centered or substantially centered on the axis x, and the surface facing the cutting side is located in the cancel pressure chamber P2 in the hydraulic clutch 100. It is a pressure receiving surface 41 that faces (see FIG. 1). The cancel plate 40 can have various forms, for example, it can have the same form as a conventional cancel plate.

As shown in FIGS. 9 and 10, the seal lip 50 is an annular or substantially annular portion centered or substantially centered on the axis x projecting from the outer peripheral end of the cancel plate 40 to the outer peripheral side. In the hydraulic clutch 100 (see FIGS. 1 and 3), the seal lip 50 is formed so as to come into contact with the piston 10 of the piston seal 1 from the inner peripheral side. For example, as shown in FIGS. 1 and 3, the seal lip 50 is formed so as to contact the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10. As shown in FIGS. Further, in the hydraulic clutch 100, the seal lip 50 is formed so as to slide on the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 when the piston seal 1 moves in the direction of the axis x. The seal lip 50 is a member that seals the cancel pressure chamber P2 on the outer peripheral side.

The cancel plate 40 is made of metal as described above, and the metal material of the cancel plate 40 includes stainless steel, SPCC (cold-rolled steel), etc., mainly SPFH (hot-rolled steel) and SAPH (hot-rolled steel). rolled steel). The cancel plate 40 is manufactured, for example, from a metal plate by pressing or forging.

The seal lip 50 is an elastic body as described above, and the elastic material of the seal lip 50 is, for example, a rubber-like elastic material. Examples of rubber-like elastic materials for the seal lip 50 include nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), fluororubber (FKM), silicone rubber, and styrene-butadiene rubber (SBR). Synthetic rubber such as

FIG. 11 is a partially enlarged cross-sectional view showing an enlarged portion of the seal lip 50 of the canceller seal 2 shown in FIG. As described above, the seal lip 50 has the main lip portion 51 , the sub-lip portion 52 , and the groove 53 formed between the main lip portion 51 and the sub-lip portion 52 .

The main lip portion 51 is a portion that protrudes toward the outer peripheral side of an annular or substantially annular shape centered or substantially centered on the axis x. Specifically, as shown in FIGS. It protrudes from the side end (peripheral end 42) toward the outer peripheral side (in the direction of arrow a) while being inclined toward the cutting side (in the direction of arrow c). The main lip portion 51 is formed to slidably contact the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 in the hydraulic clutch 100 (see FIG. 1). For example, the main lip portion 51 is formed such that a corner portion 54a on the outer peripheral side (in the direction of arrow a) of the tip portion 54 comes into slidable contact with the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10. .

Further, the main lip portion 51 can be deformed toward the groove 53 by the hydraulic pressure received from the hydraulic fluid in the cancel pressure chamber P2 in the hydraulic clutch 100 . Specifically, the main lip portion 51 is deformable such that the cross-sectional area of the groove 53 is reduced when the hydraulic clutch 100 receives hydraulic pressure from the hydraulic fluid in the cancel pressure chamber P2. It is preferable that the main lip portion 51 is formed in such a shape that the area of the opening 53a of the groove 53 does not decrease when the main lip portion 51 is deformed. For example, as shown in FIG. 11, the side surface 55 of the main lip portion 51 facing the cutting side (cancellation pressure chamber P2 side) has a concave portion 55a that is concave in the thickness direction of the main lip portion 51 at the root side portion. formed. Since the thickness of the main lip portion 51 on the root side is reduced by the recess 55a, the hydraulic pressure of the hydraulic oil in the cancel pressure chamber P2 is applied to the outer peripheral surface 55 of the main lip portion 51 in the hydraulic clutch 100. When applied, the main lip portion 51 tends to bend from the root side portion such that the tip portion 54 faces the inner peripheral side. The shape of the main lip portion 51 that can be deformed so that the cross-sectional area of the groove 53 decreases when the main lip portion 51 receives the hydraulic pressure of the hydraulic oil in the cancel pressure chamber P2 in the hydraulic clutch 100 is another shape. There may be. The thickness direction of the main lip portion 51 is a direction perpendicular to the direction in which the main lip portion 51 protrudes (projection direction).

The sub-lip portion 52 is a portion that protrudes toward the outer peripheral side of an annular or substantially annular shape centered or substantially centered on the axis x. Specifically, as shown in FIGS. It protrudes from 42 at an angle toward the cutting side (direction of arrow c) toward the outer peripheral side (direction of arrow a). The sub-lip portion 52 is formed so as to slidably contact the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 in the hydraulic clutch 100 (see FIG. 1). For example, the sub-lip portion 52 is formed such that the outer peripheral portion (outer peripheral portion 56 a ) of the tip portion 56 comes into slidable contact with the inner peripheral surface 12 a of the clutch pressing portion 12 of the piston 10 .

The sub-lip portion 52 does not protrude parallel to the main lip portion 51, as shown in FIG. More specifically, the projecting direction of the sub-lip portion 52 is not parallel to the projecting direction of the main lip portion 51 , but is inclined toward the cutting side with respect to the projecting direction of the main lip portion 51 . The sub lip portion 52 may protrude in parallel with the main lip portion 51 and may not be inclined toward the cutting side from the projecting direction of the main lip portion 51 . Further, the sub-lip portion 52 is formed, for example, so as to taper toward the distal end portion 56 .

The sub-lip portion 52 is spaced from the main lip portion 51 on the connection side in the thickness direction of the main lip portion 51 . is formed in As shown in FIG. 11, the groove 53 has an opening 53a on the outer peripheral side and is open at the opening 53a. For example, the groove 53 is inclined toward the cancel pressure chamber P2 side (cutting side) toward the outer peripheral side.

Next, the action of the canceller seal 2 having the above configuration will be described. FIG. 12 is a cross-sectional view showing an enlarged portion of the seal lip 50 of the canceller seal 2 in the hydraulic clutch 100 when no hydraulic pressure is generated in the cancel pressure chamber P2. As shown in FIG. 12 , when the canceller seal 2 used in the hydraulic clutch 100 is used, the corner portion 54 a of the main lip portion 51 and the outer peripheral portion 56 a of the sub-lip portion 52 are aligned with the inner peripheral portion of the clutch pressing portion 12 of the piston 10 . It is in slidable contact with the surface 12a. As a result, the outer peripheral side of the cancel pressure chamber P2 is sealed.

Further, in use, the hydraulic oil supplied in the cancel pressure chamber P2 is interposed in the sliding portion between the corner portion 54a of the main lip portion 51 and the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10. Then, an oil film is formed, and is interposed in the sliding portion between the outer peripheral portion 56a of the sub-lip portion 52 and the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10, and an oil film is formed. In addition, hydraulic oil is accumulated in the grooves 53 . Accordingly, the main lip portion 51 and the sub-lip portion 52 smoothly slide on the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 as the piston seal 1 moves in the direction of the axis x.

When hydraulic pressure based on the centrifugal force applied to the hydraulic fluid is generated in the cancel pressure chamber P2, the main lip portion 51 is pressed against the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 by this hydraulic pressure. When the hydraulic pressure based on the centrifugal force of hydraulic oil increases, the main lip portion 51 is pressed against the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 more strongly. Therefore, when the hydraulic pressure based on the centrifugal force of the hydraulic oil increases, the oil film intervening in the sliding portion of the main lip portion 51 is more strongly crushed and scraped out, and the oil film becomes thinner and the main lip portion becomes thinner. 51 is easily worn. In addition, since the main lip portion 51 is pressed against the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 more strongly, the hydraulic oil is less likely to be supplied from the cancel pressure chamber P2 to the sliding portion of the sub-lip portion 52. are prone to wear.

On the other hand, in the canceller seal 2 according to the embodiment of the present invention, as shown in FIG. 13, the driving oil pressure in the driving pressure chamber P1 is released, and the piston seal 1 is pushed by the return spring 140 to cut in the cutting direction. , the seal lip 50 slides relatively in the connecting direction, and hydraulic oil accumulated in the groove 53 flows out from the groove 53 . Hydraulic oil flowing out from the groove 53 is supplied to the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52 . As a result, the thickness of the oil film formed on the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52 can be maintained. Therefore, even if the hydraulic pressure in the cancel pressure chamber P2 increases, the wear of the main lip portion 51 and the sub-lip portion 52 can be suppressed.

On the other hand, as shown in FIG. 14, when hydraulic fluid is supplied into the driving pressure chamber P1 and driving hydraulic pressure is generated in the driving pressure chamber P1, the piston seal 1 moves toward the connecting side. As a result, the seal lip 50 of the canceller seal 2 slides relatively toward the cutting side. As a result, the sub-lip portion 52 collects hydraulic oil in the groove 53 . Thereby, hydraulic oil can be introduced into the groove 53 .

As described above, the sub-lip portion 52 is inclined toward the outer peripheral side toward the cutting side. That is, the sub-lip portion 52 contacts the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 at a shallow angle of inclination. Therefore, the hydraulic oil can be easily collected in the groove 53 by sliding the sub-lip portion 52 toward the cutting side. Thus, in order to make it easier to collect hydraulic oil in the groove 53, the sub-lip portion 52 is preferably formed so as to be inclined toward the outer peripheral side from the cutting side.

Further, the groove 53 is inclined toward the cutting side toward the outer peripheral side, as described above. That is, the groove 53 has a shallow inclination angle with respect to the inner peripheral surface 12 a of the clutch pressing portion 12 of the piston 10 . Therefore, by sliding the seal lip 50 toward the cutting side, it is possible to easily introduce the working oil into the groove 53 . In this way, in order to facilitate the introduction of hydraulic fluid into the grooves 53, it is preferable that the grooves 53 are formed so as to be inclined toward the outer peripheral side toward the cutting side. Further, when the groove 53 is inclined toward the cutting side toward the outer peripheral side, the hydraulic oil in the groove 53 can be easily discharged from the opening 53a by sliding the seal lip 50 toward the cutting side.

Further, as shown in FIG. 13, the main lip portion 51 is deformed toward the groove 53 by the hydraulic pressure based on the centrifugal force of the hydraulic oil in the cancel pressure chamber P2, and the cross-sectional area of the groove 53 is reduced. As a result, the hydraulic fluid accumulated in the grooves 53 can be forcibly flowed out from the grooves 53 . Therefore, the main lip portion 51 is pressed against the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 by the hydraulic pressure based on the centrifugal force of the hydraulic oil, and the oil film on the sliding portion of the main lip portion 51 becomes thin, and the sub-lip portion Even if the oil film on the sliding portion of 52 becomes thin, the supply of hydraulic oil from the groove 53 can suppress the reduction of the oil film on the sliding portion of the main lip portion 51 and the sub-lip portion 52 and maintain the oil film.

In particular, when the hydraulic pressure based on the centrifugal force of the hydraulic oil in the cancel pressure chamber P2 increases as the rotation speed of the drive source increases, the main lip portion 51 is pressed more strongly toward the groove 53, and the main lip portion 51 slides. It is conceivable that the reduction of the oil film increases, and as a result, the reduction of the oil film on the sliding portion of the sub-lip portion 52 increases, and the oil film on the sliding portions of the main lip portion 51 and the sub-lip portion 52 disappears. On the other hand, as described above, the main lip portion 51 is deformed toward the groove 53 and the hydraulic oil accumulated in the groove 53 can be forcibly flowed out from the groove 53. It is possible to prevent the oil film from disappearing from the sliding portion of the sub-lip portion 52 . In this manner, the canceller seal 2 can maintain the oil film on the sliding portions of the main lip portion 51 and the sub-lip portion 52 even if the hydraulic pressure based on the centrifugal force of the hydraulic oil in the cancel pressure chamber P2 increases. .

The higher the hydraulic pressure based on the centrifugal force of the hydraulic fluid in the cancel pressure chamber P2, the more the main lip portion 51 is deformed toward the groove 53, and the pushing force of the hydraulic fluid accumulated in the groove 53 can be increased. Therefore, even if the main lip portion 51 and the sub-lip portion 52 are strongly pressed against the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10, the oil film can be supplied to the sliding portions of the main lip portion 51 and the sub-lip portion 52. can do.

As described above, in terms of supplying the hydraulic oil in the groove 53 to the sliding portion, the main lip portion 51 is arranged so that the cross-sectional area of the groove 53 is reduced by the force acting on the pressure receiving surface 41 from the cutting side. A shape that can be deformed to the 53 side is preferable. In addition, it is preferable that the main lip portion 51 be deformable into a shape that does not reduce the area of the opening 53a of the groove 53 due to the force acting on the pressure receiving surface 41 from the cut side.

Further, as described above, the main lip portion 51 is deformed toward the groove 53 by the hydraulic pressure in the cancel pressure chamber P2, and the cross-sectional area of the groove 53 is reduced. As it goes on, the main lip portion 53 returns to its original shape, and the cross-sectional area of the groove 53 expands so as to return to its original size. By restoring the cross-sectional area of the groove 53, the hydraulic oil can be sucked into the groove 53 through the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52 when the hydraulic pressure is released. This suction can thicken the oil film on the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52 .

Further, when the pressing force of the hydraulic oil that presses the main lip portion 51 and the sub-lip portion 52 against the inner peripheral surface 12a of the clutch pressing portion 12 of the piston 10 is released, the hydraulic oil is released from the sliding portion of the main lip portion 51 and the sub-lip portion 52. It moves into the groove 23 through the sliding portion of the sub-lip portion 52 . As a result, hydraulic oil can be stored in the groove 53, and the oil film on the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52 can be thickened.

In this manner, the seal lip 50 can guide the hydraulic fluid into the groove 53 when the hydraulic pressure of the hydraulic fluid in the cancel pressure chamber P2 is released, and the main lip portion 51 is moved by the hydraulic pressure in the cancel pressure chamber P2. Even if the working oil is discharged from the groove 53 by being pressed, the working oil can be stored in the groove 53 again. Further, as the seal lip 50 slides, the working oil can be guided into the groove 53, and even if the working oil is discharged from the groove 53, the working oil can be stored in the groove 53 again. In this process, the oil film on the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52, which has been thinned or lost, can be thickened or regenerated. For this reason, the seal lip 50 will not operate in the groove 53 even if the generation and release of the driving hydraulic pressure in the drive pressure chamber P1 are repeated, and even if the generation and release of the hydraulic pressure in the cancel pressure chamber P2 are repeated. By repeating the discharge of oil and the supply of hydraulic oil into the groove 53, the oil film on the sliding portion of the main lip portion 51 and the sliding portion of the sub-lip portion 52 can be maintained. Wear of the portion 52 can be further suppressed. Even if a high hydraulic pressure is applied to the main lip portion 51, the working oil is supplied into the grooves 53 by releasing the hydraulic pressure, so that the above effect can be obtained regardless of the magnitude of the hydraulic pressure.

As described above, according to the canceller seal 2 according to the embodiment of the present invention, reduction of the oil film at the contact portion of the seal lip 50 can be suppressed regardless of the magnitude of the acting hydraulic pressure.

Although the embodiments of the present invention have been described above, the present invention is not limited to the piston seal 1 or the canceller seal 2 as the sealing device for the hydraulic actuator according to the above-described embodiments of the present invention. It includes all aspects that fall within the scope of the concept and claims. Moreover, each configuration may be selectively combined as appropriate so as to achieve at least part of the above-described problems and effects. For example, the shape, material, arrangement, size, etc. of each component in the above embodiment may be changed as appropriate according to the specific usage of the present invention.

The piston seal 1 and the canceller seal 2 as the hydraulic actuator sealing device according to the present invention are applied to the hydraulic clutch, but the application target of the hydraulic actuator sealing device according to the present invention is not limited to this. However, the present invention can be applied to all configurations that can utilize other effects of the present invention.

In the above-described embodiment, the hydraulic clutch 100 employs the piston seal 1 and the canceller seal 2 according to the embodiment of the present invention. It is not limited to a mode in which both canceller seals are applied. The present invention also includes a mode in which either one of the piston seal according to the present invention and the canceller seal according to the present invention is applied.

Further, in the outer peripheral seal lip 20 of the piston seal 1, the main lip portion 21 may have a groove 27 at its tip portion 24 communicating with the groove 23 extending in the direction of the axis x. Specifically, as shown in FIGS. 15 and 16, the groove 27 is provided in the corner portion 24a of the tip portion 24 of the main lip portion 21, and the corner portion 24a is recessed inwardly. groove to form. The groove 27 extends linearly or substantially linearly parallel or substantially parallel to the axis x. The groove 27 may extend obliquely with respect to the axis x, or may extend curvedly. The groove 27 communicates between the driving pressure chamber P1 and the groove 23 when no driving hydraulic pressure is generated in the driving pressure chamber P1 shown in FIG. is formed in such a shape that the communication between the drive pressure chamber P1 and the groove 23 is cut off when the pressure is generated.

Specifically, in a state in which the main lip portion 21 is deformed toward the groove 23 side by the driving oil pressure in the driving pressure chamber P1 and is bent from the driving pressure chamber P1 side, as shown in FIG. The portion (blocking portion 24b) of the corner portion 24a of the main lip portion 21 adjacent to the connection side (arrow d direction side) comes into contact with the inner peripheral surface 113a of the outer peripheral cylindrical portion 113, the communication of the groove 27 is lost, and the driving The groove 27 is formed so that hydraulic pressure does not escape to the connection side through the groove 27. - 特許庁On the other hand, when the drive pressure is not generated in the drive pressure chamber P1, the deformation of the main lip portion 21 due to the drive pressure is released, and the blocking portion 24b does not contact the inner peripheral surface 113a of the outer cylindrical portion 113. The main lip portion 21 contacts the inner peripheral surface 113a of the outer cylindrical portion 113 at the portion where the groove 27 is formed. there is

The main lip portion 21 may have a plurality of grooves 27, or may have only one. When the main lip portion 21 has a plurality of grooves 27, the grooves 27 are provided at intervals in the circumferential direction, for example, at equal angular intervals in the circumferential direction. The grooves 27 facilitate the suction of hydraulic fluid into the grooves 23 and the discharge of hydraulic fluid from the grooves 23 . Similarly, the main lip portion 31 of the inner peripheral seal lip 30 of the piston seal 1 and the main lip portion 51 of the seal lip 50 of the canceller seal 2 may be formed with such a groove 27 extending in the direction of the axis x.

DESCRIPTION OF SYMBOLS 1... Piston seal 2... Canceller seal 3... Piston mechanism 4... Elastic body part 10... Piston 11... Pressure receiving part 11a... Pressure receiving surface 12... Clutch pressing part 12a... Inner peripheral surface 20... Outer periphery Seal lip 21 Main lip portion 22 Sub-lip portion 23 Groove 23a Opening 24 Tip portion 24a Corner portion 24b Blocking portion 25 Side surface 25a Concave portion 26 Tip portion , 26a... Outer peripheral part 27... Groove 30... Inner peripheral seal lip 31... Main lip part 32... Sub lip part 33... Groove 33a... Opening 34... Tip part 34a... Corner part 35... Side surface , 35a... recessed part, 36... tip part, 36a... outer peripheral part, 40... cancel plate, 41... pressure receiving surface, 42... outer peripheral end, 50... seal lip, 51... main lip part, 52... sub lip part, 53... groove, 53a... Opening 54... Tip part 54a... Corner part 55... Side face 55a... Recessed part 56... Tip part 56a... Outer peripheral part 100... Hydraulic clutch 110... Clutch cylinder 111... Inner cylindrical part, DESCRIPTION OF SYMBOLS 111a... Outer peripheral surface 112... Disk part 112a... Side surface 113... Outer peripheral cylindrical part 113a... Inner peripheral surface 114... Space, 115... Drive oil hole, 116... Cancel oil hole, 120... Clutch hub, 121... Cylinder Part 130...Clutch 131...Drive plate 132...Driven plate 140...Return spring 141...Snap ring P1...Drive pressure chamber P2...Cancel pressure chamber

Claims (8)

A sealing device for a hydraulic actuator comprising a piston movable along an axis by hydraulic pressure in a drive pressure chamber that is an annular space,
said piston annular about said axis;
an outer circumferential seal lip attached to the piston and formed of an elastic material and formed of an elastic body for sealing the driving pressure chamber;
an inner peripheral seal lip attached to the piston and annular about the axis for sealing the driving pressure chamber on the inner peripheral side of the outer peripheral seal lip;
The outer peripheral seal lip includes a main lip portion that is annular and protrudes to the outer peripheral side around the axis, a sub-lip portion that is annular and protrudes to the outer peripheral side around the axis, and an annular shape around the axis that is open on the outer peripheral side. having a groove and
The main lip portion and the sub-lip portion are provided side by side, and the main lip portion is provided on the driving pressure chamber side of the sub-lip portion,
The groove is formed between the main lip portion and the sub-lip portion,
A sealing device for a hydraulic actuator, wherein when the main lip portion receives the hydraulic pressure in the driving pressure chamber, the cross-sectional area of the groove is reduced and hydraulic oil in the groove flows out. 2. A sealing device for a hydraulic actuator according to claim 1, wherein said main lip portion is deformable toward said groove by hydraulic pressure in said driving pressure chamber. 3. A sealing device for a hydraulic actuator according to claim 1, wherein said groove is inclined toward the driving pressure chamber side toward the outer peripheral side. 4. The sealing device for a hydraulic actuator according to claim 1, wherein the sub-lip portion is inclined toward the driving pressure chamber side toward the outer peripheral side. A sealing device for a hydraulic actuator comprising a piston movable along an axis by hydraulic pressure in a drive pressure chamber that is an annular space,
an annular cancel plate around the axis for forming a cancel pressure chamber, which is an annular space, on the opposite side of the piston and the drive pressure chamber in the hydraulic actuator;
a seal lip attached to the cancel plate and formed of an elastic material and having an annular shape around the axis for sealing the cancel pressure chamber;
The seal lip includes a main lip portion annularly projecting to the outer peripheral side around the axis, a sub-lip portion annularly projecting to the outer peripheral side around the axis, and an annular groove around the axis open on the outer peripheral side. and
The main lip portion and the sub-lip portion are provided side by side, and the main lip portion is provided on the cancel pressure chamber side of the sub-lip portion,
The groove is formed between the main lip portion and the sub-lip portion,
A sealing device for a hydraulic actuator, wherein when the main lip portion receives the hydraulic pressure in the cancel pressure chamber, the cross-sectional area of the groove is reduced and hydraulic oil in the groove flows out. 6. A sealing device for a hydraulic actuator according to claim 5, wherein said main lip portion is deformable toward said groove by hydraulic pressure in said cancel pressure chamber. 7. A sealing device for a hydraulic actuator according to claim 5, wherein said groove is inclined toward the cancel pressure chamber side toward the outer peripheral side. 8. The sealing device for a hydraulic actuator according to claim 5, wherein the sub-lip portion is inclined toward the cancel pressure chamber side toward the outer peripheral side.

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