JP2005264993A - Sealing structure for hydraulic oscillating actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seal structure capable of improving the responsibility of an actuator. <P>SOLUTION: Sealing member S1, S2 for sealing pressure chambers Y1, Y2, Z1, Z2 while slide contacting with a housing H inner periphery and a rotor R side surface are pressed toward the pressure chambers Y1, Y2, Z1, Z2, or the inner periphery of the housing H, or both of them, by pressure in the pressure chamber Y1, Y2, Z1, Z2 which becomes a high pressure side among the pressure chambers Y1, Y2, Z1, Z2. Thereby, tension acted on the sealing members S1, S2 is optimized for sealing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement in a seal structure of a hydraulic oscillation type actuator.

Conventionally, each pressure chamber of a hydraulic oscillating actuator that includes a housing and a rotor that is partitioned into two pressure chambers and that is rotatably inserted into the housing is formed in the housing. In the seal structure that seals, the housing is provided with an annular notch extending from both ends of each pressure chamber, an annular step provided on the outer periphery of the rotor is provided, and the seal member is provided with an annular notch and an annular step. In the space formed by the above, the axial direction of each pressure chamber is sealed (for example, see Patent Documents 1 and 2).
JP-A-7-186681 (page 4, left column, lines 35 to 40, FIG. 1) JP-A-10-54405 (page 4, right column, lines 32 to 38, FIG. 1)

  However, it may be pointed out that the conventional seal structure described above may cause the following problems.

  In the above-described conventional seal structure, hydraulic oil is supplied from the pressure chamber side to the back surface of the seal member in the space in which the seal member is accommodated, that is, in the space on the opposite side of the pressure chamber from the seal member. It leaked slightly and flowed in.

  The pressure increase in the gap is caused by leakage of the hydraulic oil from the seal member, but is delayed with respect to the pressure increase in the pressure chamber of the hydraulic oscillation actuator.

  Accordingly, when the pressure in the pressure chamber rises, the pressure rise in the gap is delayed in time, and the pressure on the housing and the rotor (the tight pressure) is kept on the seal member until the pressure in the gap rises sufficiently. Force) does not act sufficiently, so that the amount of hydraulic oil leaking from the seal member increases, so-called hydraulic oil blow-through occurs, and the pressure rise in the pressure chamber is delayed.

  This is particularly noticeable when the pressure in the pressure chamber is increased instantaneously, which causes a deterioration in the response of the hydraulic oscillation actuator.

  On the other hand, when the pressure in the pressure chamber is lowered, high pressure hydraulic oil remains in the gap even though the pressure in the pressure chamber is lowered, which is more than necessary for the seal member. As a result, the sealing member is strongly pressed against the housing and the rotor, and a frictional resistance that inhibits the rotational movement of the rotor with respect to the housing is generated.

  Further, since the seal member generates frictional resistance more than necessary, the wear of the seal member is promoted, causing deterioration of the durability of the seal member.

  Accordingly, the present invention has been developed to improve the above-described problems, and an object of the present invention is to provide a seal structure capable of improving the response of a hydraulic oscillation type actuator. is there.

  In order to achieve the above-described object, the present invention provides a seal for a hydraulic oscillating actuator that seals between a hollow housing and a rotor that is rotatably inserted into the housing and divides the housing into two pressure chambers. In the structure, the pressure chamber is provided with a pair of seal members that are in sliding contact with the inner periphery of the housing and the side surfaces of the rotor and seals both ends of each pressure chamber, and the seal member is a high pressure side of the two pressure chambers. The pressure is pressed toward the pressure chambers, the inner periphery of the housing, or both.

  According to the present invention, the tightening force acting on the seal member quickly increases as the pressure in the pressure chamber increases, and at the same time increases in proportion to the pressure increase in the pressure chamber, so the tightening force acting on the seal member becomes moderate. It is possible to prevent the hydraulic oil from being blown through.

  In addition, since the hydraulic oil can be prevented from being blown through, the responsiveness of the hydraulic oscillation actuator is greatly improved without impeding the rapid pressure rise in the pressure chamber, and the control thereof is facilitated. .

  Conversely, even when the pressure in the pressure chamber is reduced, the tightening force acting on the seal member is quickly reduced, so that an unnecessarily large force acts on the seal member and the seal member is strongly applied to the rotor and the housing. It is possible to prevent the adverse effect of causing unnecessary frictional resistance that impedes the rotational movement of the rotor relative to the housing. That is, the smooth swing movement of the hydraulic swing actuator is not hindered, and this also contributes to the response of the hydraulic swing actuator.

  In addition, since the sealing member does not receive excessive tension, it does not generate large frictional resistance as in the past, so the wear of the sealing member is not accelerated and the durability of the sealing member is improved compared to the conventional case. To do.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a longitudinal cross-sectional view of a hydraulic oscillation actuator in which a seal structure is embodied. FIG. 2 is a cross-sectional view taken along line AA of the hydraulic oscillation type actuator in which the seal structure is embodied. FIG. 3 is an enlarged vertical sectional view of a seal portion in which the seal structure is embodied.

  The seal structure of the hydraulic oscillation actuator of the present invention is specifically embodied in, for example, a seal portion of a hydraulic oscillation actuator constituted by a housing H and a rotor R as shown in FIG. This will be described in detail.

  As described above, the hydraulic oscillation type actuator includes the housing H and the rotor R. The housing H includes a hollow main body 10 and a cap body that closes the left and right ends of the main body 10 as shown in FIGS. 11 and 12, and convex portions 10 a and 10 b facing each other are provided on the inner peripheral side of the main body 10, and a pair of plates 61 and 61 extending from the distal end side to the proximal end of the convex portions 10 a and 10 b. The rubber plate 62 is inserted between the plates 61 and 61, and the rubber plate 62 is covered between the plates 61 and 61 from the front end side of the convex portions 10a and 10b. A seal 63 that is in sliding contact with a side surface of a rotor R, which will be described later, is inserted.

  Further, the cap body 11 is formed in a cylindrical shape, and an annular notch 11a is provided on the inner peripheral left end side in FIG. 1, and a bearing insertion portion 11b having a smaller diameter than the annular notch 11a extending from the annular notch 11a. And the bearing B1 is fitted into the inner periphery of the bearing insertion portion 11b.

  1 is fitted into the outer periphery of the left end of the cap body 11, and the gap between the cap body 11 and the main body 10 is sealed by an O-ring 16 provided on the outer periphery of the cap body 11. .

  On the other hand, the cap body 12 is composed of a closed portion 12c formed in a bottomed cylindrical shape and a rod portion 12d extending from the left end of the closed portion 12c in FIG. 1, and on the left end side (not shown) of the rod portion 12d. A screw groove is formed on the outer periphery. For example, the left end of the rod portion 12d can be connected to a vehicle stabilizer (not shown).

  Further, an annular notch 12a is provided on the inner peripheral right end side in FIG. 1 of the closing portion 12c, and a bearing insertion portion 12b having a smaller diameter than the annular notch 12a extending from the annular notch 12a is provided. A bearing B2 is fitted into the inner periphery of 12b.

  The left end of the main body 10 in FIG. 1 is fitted to the outer periphery of the closing portion 12c, and the gap between the cap body 12 and the main body 10 is sealed by an O-ring 15 provided on the outer periphery of the closing portion 12c. .

  A rotor R is inserted into the housing H described above, and the rotor R has a shaft 20 and a large-diameter portion formed at an intermediate portion of the shaft 20 as shown in FIGS. 21 and a pair of vanes 25, 25 extending diagonally from the large-diameter portion 21, and a pair of plates 26, 26 are accommodated from the tip side to the base end of the vanes 25, 25. A rubber plate 27 is inserted between the plates 26, 26. Further, the rubber plate 27 is covered between the plates 26, 26 from the front end side of the vanes 25, 25, and the inner periphery of the main body 10 is convex. A seal 28 that is in sliding contact with a portion where the portions 10a and 10b are not provided is inserted.

  The shaft 20 is rotatably inserted into the bearings B1 and B2, and is supported by the bearings B1 and B2 at both ends of the rotor R. The vanes 25 and 25 are formed by the convex portions 10a and 10b of the main body 10, respectively. 10b, and in the housing H, the rotor R communicates with one of the pressure chambers Y1, Y2 communicated by the communication hole 29 provided in the large diameter portion 21 and the communication provided in the large diameter portion 21. The other pressure chambers Z1 and Z2 communicated with each other through the hole 30 are separated. Incidentally, a pair of hydraulic oil supply holes (not shown) are formed in the cap body 12, and the hydraulic oil is supplied to one of the pressure chambers Y1, Y2 and the other pressure chambers Z1, Z2 through the hydraulic oil supply holes, respectively. It is possible to supply. A screw groove is provided on the right end side (not shown) of the shaft 20 in the same manner as the left end of the cap body 12, and can be connected to, for example, a vehicle stabilizer.

  Further, the seal 63 provided on the convex portions 10a and 10b of the main body 10 is in sliding contact with the outer periphery of the large diameter portion 21 where the vanes 25 and 25 are not provided, and the seals 28 and 28 provided on the vanes 25 and 25 are slidably contacted. Is in sliding contact with the inner periphery of the main body 10 where the convex portions 10a and 10b are not provided, and the circumferential directions of the pressure chambers Y1, Y2, Z1 and Z2 are sealed by these seals 28, 28, 63 and 63. ing.

  Further, annular step portions 22 and 23 are formed on the left and right sides in FIG. 1 by the large diameter portion 21 provided in the intermediate portion of the shaft 20 of the rotor R, and the side walls of the annular step portions 22 and 23 in FIG. The cap bodies 11 and 12 are provided so as to be positioned substantially on a straight line. The diameter of the large diameter portion 21 is set to be approximately the same as the inner diameter of the annular notches 11a and 12a. The annular step portions 22 and 23 and the annular notches 11a and 12a form back pressure chambers R1 and R2.

  Further, in the back pressure chamber R1, as shown in FIG. 3, an annular substantially right-angled triangular backup ring 45 having an outer shape substantially the same as the inner diameter of the annular notch 11a and an annular substantially right-angled triangular sealing ring are provided. 44, and a leaf spring 46 as a spring member for urging the seal member S1 toward the pressure chambers Y1, Y2, Z1, Z2 side. Has been stowed. Since the seal ring 44 and the backup ring 45 have the above shape, when the backup ring 45 is urged toward the left in FIG. The seal ring 44 is pressed against and brought into contact with the side wall of the annular step portion 22 and the inner diameter portion of the annular notch 11a, whereby the axial directions of the pressure chambers Y1, Y2, Z1, and Z2 are sealed. ing.

  On the other hand, in the back pressure chamber R2, as in the back pressure chamber R1, an annular substantially right triangular backup ring 42 having an outer shape substantially the same as the inner diameter of the annular notch 12a and an annular substantially right triangular shape are provided. A seal member S2 formed by combining the seal ring 41 so as to have a substantially square cross section, and a leaf spring as a spring member that urges the seal member S2 toward the pressure chambers Y1, Y2, Z1, and Z2. 43 is stored. Since the seal ring 41 and the backup ring 42 have the above shapes, when the backup ring 42 is urged to the right in FIG. 1 by the leaf spring 43, the seal ring 41 is inclined to the oblique side of the backup ring 42. The seal ring 41 is pressed against and contacted with the side wall of the annular step portion 23 and the inner diameter portion of the annular notch 12a, thereby sealing the axial directions of the pressure chambers Y1, Y2, Z1, and Z2. ing.

  Furthermore, a passage 31 that opens from the left end side in FIG. 1 of the shaft 20 is provided in the shaft center portion of the shaft 20, and a passage 33 that communicates with the passage 31 at a position eccentric from the shaft center portion, and the shaft 20. 1 is opened from the right side in FIG. 1 and communicates with the passage 33. The back pressure chambers R1 and R2 are communicated with each other via the passages 31, 33, and 34. Therefore, in this case, the first passage is composed of the passages 31, 33, and 34. In addition, since the passages 31 and 34 are provided at the above-described positions, the hydraulic oil always passes between the bearings B1 and B2 and the shaft 20 before reaching the back pressure chambers R1 and R2. The situation where the lubricating oil between the bearing 20 and the bearings B1 and B2 is insufficient is prevented, and smooth rotation of the shaft 20 is ensured.

  The large-diameter portion 21 is provided with a passage 32 that communicates the pressure chamber Y1 and the pressure chamber Z1. The passage 32 is eccentrically connected in the middle of the passage 33. Therefore, in this case, the second passage is constituted by the passage 32. Further, the diameter of the passage 32 is enlarged on the pressure chamber Y1 side, and a spherical valve body 51 is inserted into the enlarged diameter portion, and the valve body 51 is prevented from coming out of the passage 32. A plug 52 is fitted. The passage 32 is provided so as to penetrate from the side portion of the one vane 25 to the side portion of the other vane 25. Therefore, the passage 32 is blocked even when the vanes 25, 25 and the convex portions 10a, 10b are in contact with each other. It is considered so that there is nothing to do.

  Further, the distance from the lower end in FIG. 2 that is the tip of the enlarged portion of the passage 32 to the lower end that is the tip of the plug 52 is set to be longer than the diameter of the valve body 51. It can be moved up and down. Further, the connection position between the passage 32 and the passage 33 described above is such that the passage 32 and the passage 33 that are not expanded in diameter when the valve body 51 is in contact with the lower end of the plug 52 in FIG. In contrast, when the valve body 51 moves to the lower end of the expanded diameter passage 32 and closes the unexpanded diameter passage 32, the expanded diameter passage 32 and the passage 33 are communicated with each other. It has become.

  That is, if the pressure in one pressure chamber Y1, Y2 becomes higher than the pressure in the other pressure chambers Z1, Z2, the valve body 51 communicates the passage 32 and the passage 33 that are expanded in diameter by the differential pressure, Conversely, when the pressure in the other pressure chambers Z1 and Z2 becomes higher than the pressure in one pressure chamber Y1 and Y2, the valve body 51 communicates the passage 32 and the passage 33 that are not expanded in diameter. Thus, the valve body 51 and the passage 32 function as a high-pressure priority shuttle valve. Although the high-pressure priority shuttle valve can be easily configured by the above configuration and the cost can be reduced, a high-pressure priority shuttle valve having another configuration may be provided.

  Incidentally, the right end side of the shaft 20 in FIG. 1 is sealed between the shaft 20 and the cap body 11 by the U packing U provided on the inner peripheral side of the cap body 11, and further, the right side in FIG. Is provided with a dust seal D to prevent entry of dust or water into the housing H.

  The seal structure embodied in the hydraulic oscillation actuator is configured as described above, and the operation thereof will be described below.

  For example, when the hydraulic oscillation type actuator is rotated counterclockwise in FIG. 2, that is, hydraulic oil is sent into one of the pressure chambers Y1 and Y2, and hydraulic oil is discharged from the other pressure chambers Z1 and Z2. The pressure in the pressure chambers Y1 and Y2 causes a pressure difference between the pressure in the pressure chambers Z1 and Z2, and the valve body 51 is pushed downward in FIG. Therefore, the pressure in the back pressure chambers R1 and R2 communicating with the passage 33 rises as in the pressure chambers Y1 and Y2. Here, the pressure in the back pressure chambers R1 and R2 presses the backup rings 42 and 45 in the direction in which the leaf springs 44 and 46 are urged, respectively. As a result, the seal rings 41 and 44 are pushed in the annular stage. It acts so as to press against the portions 22, 23 and the annular notches 11a, 12a, that is, to increase the pressing force acting on the seal members S1, S2. The pressure in the back pressure chambers R1 and R2 is such that the pressure chambers Y1 and Y2 and the back pressure chambers R1 and R2 communicate with each other through the passages 31, 32, 33, and 34. Rises without any delay in time. Then, the tightening force acting on the seal members S1 and S2 also increases rapidly due to the pressure increase in the pressure chambers Y1 and Y2, and at the same time increases in proportion to the pressure increase in the pressure chambers Y1 and Y2, and thus acts on the seal members S1 and S2. The tightening force is moderate and can prevent the hydraulic oil from being blown through.

  In addition, since the hydraulic fluid can be prevented from being blown through, the responsiveness of the hydraulic oscillation actuator is greatly improved without impeding the rapid pressure rise in the pressure chambers Y1 and Y2. Is also easier.

  This also applies to the case where the pressure in the other pressure chambers Z1 and Z2 is increased, and the operation is the same except that the passage 32 and the passage 33 in which the valve body 51 is not expanded are communicated.

  It should be noted that, at the beginning of the pressure increase in the pressure chambers Y1, Y2, the sealing members S1, S2 are secured with the required pressing force at that time by the urging force of the leaf springs 44, 46. Blow-through of the hydraulic oil is also prevented.

  Subsequently, conversely, when the pressure in the pressure chambers Y1, Y2 is reduced, the valve body 51 must always include at least one of the pressure chambers Y1, Y2, Z1, Z2 and the back pressure chambers R1l, R2. Therefore, the pressure in the back pressure chambers R1 and R2 is also quickly reduced, the tightening force acting on the seal members S1 and S2 is quickly reduced, and the pressure is accumulated in the back pressure chambers R1 and R2. There is nothing. Therefore, a negative effect caused by the pressure in the back pressure chambers R1 and R2, that is, an excessive pressing force acts on the seal members S1 and S2, and the seal members S1 and S2 are applied to the rotor R and the housing H. It is possible to prevent an adverse effect of causing a useless frictional resistance that is strongly pressed and hinders the rotational movement of the rotor R with respect to the housing H. That is, the smooth swing movement of the hydraulic swing actuator is not hindered, and this also contributes to the response of the hydraulic swing actuator.

  Further, since the unnecessary tension force does not act on the seal members S1 and S2, the frictional resistance is not increased as in the conventional case, so the wear of the seal member is not promoted, and the durability of the seal member is also compared with the conventional one. And improve.

  In the above, the seal members S1, S2 are connected to the seal rings 41, 43 and the backup rings 42, 44 in order to efficiently apply the compressive force to the seal members S1, S2 with the pressure in the back pressure chambers R1, R2. However, the present invention is not limited to this, and the seal member may be any member that can be acted upon by the pressure in the back pressure chambers R1 and R2.

  The passages 31, 33, 34 as the first passage and the passage 32 as the second passage are provided in the rotor R, but the passage may be formed outside the housing H. The internal arrangement is superior in terms of sealing performance because there is no risk of damage to the hydraulic oscillating actuator due to interference with other members due to the passage being exposed outside the housing H.

  As described above, the seal members S1 and S2 are directed toward the annular notches 11a and 12a that are the inner periphery of the housing H and the annular step portions 22 and 23 that are the side surfaces of the rotor R with the pressure in the pressure chamber on the high pressure side. Even if only one of the annular notches 11a and 12a that are the inner periphery of the housing H or the annular step portions 22 and 23 that are the side surfaces of the rotor R is pressed, the same effect is obtained. Can be obtained.

  Furthermore, in the present embodiment, the pressure chamber Y1 and the pressure chamber Z1 are communicated by the passage 32, but the pressure chamber Y1 and the pressure chamber Z2 are communicated or the pressure chamber Y2 and the pressure chamber Z1 are communicated. Of course, it is also possible.

  In the above description, the hydraulic oscillation type actuator is a so-called double vane type actuator. However, it goes without saying that the seal structure of the present invention may be applied to a single vane type or triple vane type actuator. It is also possible to apply the present invention to a hydraulic rocking type actuator in which the interval between two vanes is an angle other than 180 degrees.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a longitudinal cross-sectional view of the hydraulic oscillation type | mold actuator by which the seal structure was embodied. It is AA sectional drawing of the hydraulic oscillation type | mold actuator by which the seal structure was embodied. FIG. 3 is an enlarged longitudinal sectional view of a seal portion of a hydraulic oscillation actuator in which a seal structure is embodied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main body 10a, 10b Convex part 11, 12 Cap body 11a, 12a Annular notch 11b, 12b Bearing insertion part 12c Closure part 12d Rod 20 Axis 21 Large diameter part 22, 23 Annular step part 25 Vane 26, 61 Plate 27, 62 Rubber Plate 28, 63 Seal 29, 30 Through hole 31, 32, 33, 34 Passage 41, 44 Seal ring 42, 45 Backup ring 43, 46 Leaf spring as a spring member 51 Valve body 52 Plug B1, B2 Bearing D Dust seal H Housing R Rotor R1, R2 Back pressure chamber S1, S2 Seal member U U packing Y1, Y2, Z1, Z2 Pressure chamber

Claims (6)

In a seal structure of a hydraulic oscillation type actuator that seals between a hollow housing and a rotor that is rotatably inserted into the housing and divides the inside of the housing into two pressure chambers, the inner periphery of the housing and the side surface of the rotor A pair of sealing members that are in sliding contact with each other and seals both ends of each pressure chamber, and the sealing member is pressured by the pressure in the pressure chamber on the high pressure side of the two pressure chambers or the inner periphery of the housing. Alternatively, a seal structure of a hydraulic oscillation type actuator characterized by being pressed toward both of them. A seal member is accommodated in a pair of back pressure chambers partitioned by a housing and a rotor on both sides of each pressure chamber, and a passage communicating each back pressure chamber and the two pressure chambers is provided in the middle of the passage. The seal structure of the hydraulic oscillation type actuator according to claim 1, further comprising a high-pressure priority shuttle valve. The back pressure chamber is defined by an annular notch extending from both sides of each pressure chamber on the inner periphery of the housing, and an annular step provided on the outer periphery of the rotor. The ring seal and the backup ring formed in an annular shape with a substantially right-angled cross section are combined so that the ring seal and the backup ring have a square cross section, and the seal member is attached to the pressure chamber side. The seal structure of the hydraulic oscillation actuator according to claim 2, further comprising a spring member that urges toward the side. A high-pressure priority shuttle valve having a first passage communicating with each back pressure chamber and a second passage communicating with each pressure chamber and having an outlet communicating with the first passage is provided in the middle of the second passage. The seal structure of the hydraulic oscillation actuator according to claim 2 or 3, 5. The hydraulic oscillating actuator seal structure according to claim 2, wherein a passage is provided in the rotor. A high-pressure priority shuttle valve is fitted to the enlarged diameter portion provided at a portion where the first passage of the second passage is communicated, a spherical valve body movably accommodated in the enlarged diameter portion, and the enlarged diameter portion. And a valve body selectively seated on the distal end portion of the enlarged diameter portion and the distal end portion of the plug, whereby the pressure chamber on the high pressure side of the two pressure chambers and the first 6. The seal structure for a hydraulic oscillation actuator according to claim 4 or 5, wherein the seal is in communication with a passage.

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