JP2014169770A - Seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring which is improved in sealing performance.SOLUTION: A seal ring 100 has an inner peripheral surface 110 and an outer peripheral surface 120 formed into cylindrical surfaces respectively and also has side faces 130, 140 on both sides formed into planes, and the side faces 130, 140 on both the sides are provided with annular lips 150, 160 which are inclined away from plane parts and then inclined toward the plane parts from a radially inner side to an outer side. Those lips 150, 160 are so designed that inclined parts 151, 161 inclined away from the plane parts from the radially inner side to the outer side are larger in gradient to the plane parts than inclined parts 152, 162 inclined toward the plane parts from the radially inner side to the outer side.

Description

  The present invention relates to a seal ring that seals a gap between end surfaces of two members.

  2. Description of the Related Art Conventionally, a hydraulic pump such as an axial piston pump has been provided with a seal ring that seals a gap between end surfaces of two members having a passage through which oil passes. Generally, a rubber-like elastic O-ring is used as such a seal ring. However, in an environment where the hydraulic pressure fluctuation (pulsation or the like) is large, the O-ring does not behave stably and the sealing performance becomes unstable, so a square ring having a rectangular cross section is used.

  However, when the seal ring is mounted at a location with a large degree of freedom and mounted at a location where the pulsation is very large, the square ring may not provide sufficient sealing performance. That is, in such a case, the seal ring is deformed so as to repeatedly expand and contract due to pulsation. As a result, a phenomenon occurs in which the oil flowing inside the seal ring is gradually scraped to the outside of the seal ring.

JP 2000-356182 A JP 2004-285932 A JP 2003-172227 A

  An object of the present invention is to provide a seal ring with improved sealing performance.

  The present invention employs the following means in order to solve the above problems.

That is, the seal ring of the present invention is
The second member is in close contact with the planar end surface of the first member so as to surround the opening of the passage of the fluid to be sealed formed in the first member, and is opposed to the planar end surface of the second member. The gap between the end surface of the first member and the end surface of the second member is sealed in a state of surrounding the passage of the fluid to be sealed by closely contacting the opening of the passage of the fluid to be sealed formed in In an annular and rubbery elastic seal ring,
The inner peripheral surface and the outer peripheral surface are each configured in a cylindrical surface shape, and the side surfaces on both sides are each configured in a planar shape,
The side lip on both sides is provided with annular lips that incline so as to approach the plane part after inclining away from the plane part from the radially inner side to the outer side,
These lips are inclined so that the inclination of the inclined portion inclined toward the outer side from the radial portion toward the outer side in the radial direction is closer to the flat portion from the inner side toward the outer side in the radial direction. It is designed to be larger than the gradient of the inclined portion with respect to the plane portion.

According to the present invention, since the side surfaces on both sides of the seal ring are each formed in a planar shape, the behavior can be stabilized compared to an O-ring or the like. Further, even if the seal ring is deformed so as to repeat the diameter expansion and contraction due to fluctuation (pulsation) of the fluid to be sealed, the lip configured as described above is provided. Scratching the target fluid radially outward can be suppressed.

  The lips provided on the side surfaces on both sides may be provided at the end portions on the inner peripheral surface side of the respective side surfaces.

  Thereby, it can suppress effectively that the fluid to be sealed leaks radially outward from the seal ring.

  A plurality of the lips provided on the side surfaces on both sides may be provided concentrically on each side surface.

  As a result, it is possible to suppress the scraping of the fluid to be sealed radially outward by each lip portion, and to be able to hold the fluid to be sealed between the lip and the lip, thereby synergistically sealing the target. Fluid leakage can be suppressed.

  Of the lips provided on the side surfaces on both sides, the lip on the innermost peripheral surface side is preferably provided at the end on the inner peripheral surface side of each side surface.

  Thereby, as above-mentioned, it can suppress effectively that the fluid to be sealed leaks radially outward from the seal ring.

The first member is provided with an annular notch along the opening of the passage, and the notch has a planar end surface and a cylindrical surface,
The seal ring may be designed so that one of the side surfaces on both sides is in close contact with the planar end surface of the notch-shaped portion and the outer peripheral surface is in close contact with the cylindrical surface of the notch-shaped portion.

  Note that the “notch-like portion” means a portion in a notched state, and does not necessarily mean a portion obtained by cutting.

  Thereby, in the state where the pressure of the fluid to be sealed is high, the seal ring expands in diameter, and the outer peripheral surface is in close contact with the cylindrical surface in the notch-shaped portion, so that the sealing performance can be further improved.

  In addition, said each structure can be employ | adopted combining as much as possible.

  As described above, according to the present invention, the sealing performance can be improved.

FIG. 1 is a schematic cross-sectional view showing a sealing structure according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a sealing structure according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the seal ring according to the first embodiment of the present invention. FIG. 4 is a partially enlarged view of FIG. FIG. 5 is a schematic cross-sectional view of a seal ring according to Embodiment 2 of the present invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

Example 1
With reference to FIGS. 1-4, the seal ring which concerns on Example 1 of this invention is demonstrated. In this embodiment, a case where a seal ring is used for a hydraulic pump such as an axial piston pump will be described as an example. Therefore, the fluid to be sealed is oil, and the oil flows through the passage with pulsation.

<Sealing structure>
In particular, a sealing structure using the seal ring 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 shows a state in which the hydraulic pressure in the passage R is high and positive pressure is acting on the inner peripheral surface of the seal ring 100, and FIG. 2 shows a state in which the hydraulic pressure in the passage R is low and negative on the inner peripheral surface of the seal ring 100. The state where the pressure is acting is shown. 1 and 2, the seal ring 100 is shown in a simplified diagram. 1 and 2 are schematic cross-sectional views cut along a plane including the central axis of the seal ring 100.

  The seal ring 100 according to the present embodiment is used for sealing a gap between end surfaces of two members (hereinafter referred to as a first member 200 and a second member 300). Here, passages 210 and 310 through which oil flows are formed in the first member 200 and the second member 300, respectively. The first member 200 and the second member 300 are fixed so that the passage 210 and the passage 310 are connected to each other and the end faces face each other. Thereby, in the case of a present Example, the flow path (passage | path R) through which oil flows from the 2nd member 300 side to the 1st member 200 side is formed. The seal ring 100 is used to suppress oil leakage from the gap between the end surfaces of the first member 200 and the second member 300. More specific description will be given below.

  The seal ring 100 is in close contact with the planar end surface 221 of the first member 200 so as to surround the opening of the passage 210 formed in the first member 200, and the planar end surface 320 of the second member 300. The second member 300 is in close contact with the opening of the passage 310 formed in the second member 300. Thus, the seal ring 100 seals the gap between the end surface 221 of the first member 200 and the end surface 320 of the second member 300 in a state of surrounding the oil passage R.

  Here, in the present embodiment, the first member 200 is provided with an annular notch 220 along the opening of the passage 210. The notch 220 is composed of the planar end surface 221 and the cylindrical surface 222 described above. In the seal ring 100, one of the side surfaces 130 on both sides is in close contact with the planar end surface 221 in the notch-shaped portion 220, and the outer peripheral surface 120 is in close contact with the cylindrical surface 222 in the notch-shaped portion 220. Designed to.

  As described above, the oil flows through the passage R with pulsation, and the oil pressure in the passage R varies periodically. Therefore, in a state where the hydraulic pressure in the passage R is high, positive pressure acts on the inner peripheral surface of the seal ring 100, and the seal ring 100 is expanded (see FIG. 1). In addition, the arrow X1 in FIG. 1 has shown a mode that high pressure oil flows. As a result, the outer peripheral surface 120 of the seal ring 100 is in close contact with the cylindrical surface 222 of the notch 220. When the hydraulic pressure in the passage R is low, negative pressure acts on the inner peripheral surface of the seal ring 100, and the seal ring 100 is reduced in diameter (see FIG. 2). In addition, the arrow X2 in FIG. 2 has shown a mode that low pressure oil flows. As a result, the outer peripheral surface 120 of the seal ring 100 is separated from the cylindrical surface 222 of the notch 220.

Then, when the hydraulic pressure in the passage R periodically varies, the seal ring 100 repeats the diameter expansion and the diameter reduction. Therefore, in the sliding portion between the seal ring 100 and the end surface 221 of the first member 200, a phenomenon occurs in which the side surface 130 of the seal ring 100 reciprocates in the radial direction with respect to the end surface 221. The same applies to the sliding portion between the seal ring 100 and the end surface 320 of the second member 300. Therefore, unless special measures are taken, a phenomenon occurs in which oil flowing inside the seal ring 100 is gradually scraped to the outside (atmosphere side (A)) of the seal ring 100. Therefore, the seal ring 100 according to the present embodiment employs a configuration that can suppress such oil scraping.

<Seal ring>
In particular, the seal ring 100 according to the present embodiment will be described in more detail with reference to FIGS. 3 and 4. FIG. 3 is a part of a schematic cross-sectional view of the seal ring 100 according to the present embodiment, and shows only a cut surface. Further, in FIG. 3, the end surface 221 and the cylindrical surface 222 of the notch-shaped portion 220 in the first member 200, so that the positional relationship between the seal ring 100 and the first member 200 and the second member 300 can be easily understood. The position of the end surface 320 in the second member 300 is indicated by a dotted line. FIG. 4 is an enlarged cross-sectional view of the annular lips 150 and 160 provided on the seal ring 100. 3 and 4 are part of a schematic cross-sectional view cut along a plane including the central axis of the seal ring 100.

  The seal ring 100 is an annular member made of a rubber-like elastic body, and has a so-called square ring as a basic shape. That is, the inner peripheral surface 110 and the outer peripheral surface 120 of the seal ring 100 are each configured in a cylindrical surface shape, and the side surfaces 130 and 140 on both sides are each configured in a planar shape. Here, the first member 200 and the second member 300 are fixed in a state where the seal ring 100 is attached to the notch-shaped portion 220 provided in the first member 200. As a result, the seal ring 100 is compressed by the end surface 221 of the first member 200 and the end surface 320 of the second member 300 and is in close contact with the end surfaces 221 and 320.

  The side faces 130 and 140 on both sides of the seal ring 100 are respectively provided with annular lips 150 and 160 that incline so as to approach the plane part after being inclined away from the plane part from the radially inner side to the outer side. It has been. In this embodiment, these lips 150 and 160 are provided at the end on the inner peripheral surface side. These lips 150 and 160 are inclined so that the slopes of the inclined portions 151 and 161 that are inclined away from the plane portion from the radially inner side to the outer side are inclined toward the outer side from the radially inner side. It is designed so that it may become larger than the inclination with respect to the plane part of the inclination parts 152 and 162 which incline so that it may approach. That is, the inclination angle α of the inclined portions 151 and 161 with respect to the plane portion is set to be larger than the inclination angle β of the inclined portions 152 and 162 with respect to the plane portion.

  Thereby, even when the lip 150 slides so as to reciprocate with respect to the end surface 221 of the first member 200, oil leakage can be suppressed. This reason is based on a generally known principle in a reciprocating seal and will be briefly described here. When the tip of the lip 150 slides with respect to the end surface 221, an oil film is formed on the surface of the end surface 221. The thickness of the oil film is based on the inclination angles α and β of the inclined portions 151 and 152 in the lip 150. That is, the greater the tilt angle, the thinner the oil film. More specifically, the seal ring 100 is formed on the end surface 221 when moving in the right direction in FIGS. 3 and 4 rather than the oil film formed on the end surface 221 when moving in the left direction in FIGS. The oil film is thinner. Therefore, the amount of returning oil is larger than the amount of oil leaking, and oil leakage can be suppressed. The same applies to the lip 160. In the present embodiment, as described above, since the lips 150 and 160 are provided at the end portions on the inner peripheral surface side, oil leaks radially outward (atmosphere side (A)) from the seal ring 100. Can be effectively suppressed.

  Further, in the seal ring 100 according to the present embodiment, the curved surfaces 170 and 180 (so-called R surface) are provided between the one side surface 130 and the outer peripheral surface 120 and between the other side surface 140 and the outer peripheral surface 120. ). The end surface 221 of the notch 220 and the cylindrical surface 222 are also connected by a curved surface 230 (so-called R surface). In this way, by adopting a configuration in which the curved surfaces 170 and 180 connect the one side surface 130 and the outer peripheral surface 120 and the other side surface 140 and the outer peripheral surface 120 respectively, the oil is radially outside. The effect which suppresses scraping to (atmosphere side (A)) is acquired. It should be noted that the same effect can be obtained with the chamfered shape (in the case of the present embodiment, a tapered surface) for the curved surfaces 170, 180, and 230 described above.

  The seal ring 100 has a rotationally symmetric shape and is symmetrical with respect to the center plane in the thickness direction (the center plane between the one side surface 130 and the other side surface 140). Therefore, when attaching the seal ring 100 to the notch 220, there is no need to worry about the front and back.

<Excellent points of seal ring according to this embodiment>
According to the seal ring 100 according to the present embodiment, since the side surfaces 130 and 140 on both sides thereof are configured in a planar shape, the behavior can be stabilized compared to an O-ring or the like. Further, even if the seal ring 100 is deformed so as to repeatedly expand and contract due to fluctuation (pulsation) of the oil pressure, the lip 150, 160 is provided, so that the oil is radially outward (atmosphere side). Scraping out to (A)) can be suppressed, and oil leakage can be suppressed. The reason why oil leakage can be suppressed by the lips 150 and 160 is based on a principle generally known in a reciprocating seal as described above.

  In this embodiment, when the hydraulic pressure is high, the diameter of the seal ring 100 is increased so that the outer peripheral surface 120 is in close contact with the cylindrical surface 222 of the notch 220 provided in the first member 300. It is configured. Thereby, sealing performance can be improved more.

  The seal ring 100 is connected by curved surfaces 170 and 180 between the one side surface 130 and the outer peripheral surface 120 and between the other side surface 140 and the outer peripheral surface 120. Accordingly, it is possible to suppress the oil from being scraped out to the outside in the radial direction by the portion between the one side surface 130 and the outer peripheral surface 120 and the portion between the other side surface 140 and the outer peripheral surface 120.

(Example 2)
FIG. 5 shows a second embodiment of the present invention. In the first embodiment, the configuration in which one annular lip is provided on each side surface of the seal ring is shown. However, in this embodiment, each annular lip is provided on each side surface of the seal ring. The structure in the case of providing a plurality of places is shown. Since other configurations and operations are the same as those in the first embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 5 is a part of a schematic cross-sectional view of the seal ring 100 according to the second embodiment of the present invention. FIG. 5 is a part of a schematic cross-sectional view cut along a plane including the central axis of the seal ring 100.

  The seal ring 100 according to the present embodiment is also an annular member made of a rubber-like elastic body, and has a so-called square ring as a basic shape. That is, the inner peripheral surface 110 and the outer peripheral surface 120 of the seal ring 100 are each configured in a cylindrical surface shape, and the side surfaces 130 and 140 on both sides are each configured in a planar shape.

Further, on the side surfaces 130 and 140 on both sides of the seal ring 100, annular lips 150a, 150b, 150c, which are inclined so as to approach the plane portion after being inclined away from the plane portion from the radially inner side to the outer side. A plurality of 160a, 160b, and 160c are provided. In the first embodiment, one lip 150, 160 is provided on each of the side surfaces 130, 140 on both sides of the seal ring 100, whereas in the present embodiment, a plurality of lips 150a are concentrically provided. , 150b, 150c, 160a, 160b, and 160c. The arrangement positions of the lips 150a and 160a are the same as the arrangement positions of the lips 150 and 160 in the seal ring 100 according to the first embodiment.

  These lips 150a, 150b, 150c, 160a, 160b, and 160c are also inclined planes that incline away from the plane part from the radially inner side to the outer side, similarly to the lip 150 and 160 in the first embodiment. The gradient with respect to the portion is designed to be larger than the gradient with respect to the plane portion of the inclined portion inclined so as to approach the plane portion from the radially inner side toward the outer side.

  Also in the seal ring 100 according to the present embodiment, the side surface 130 and the outer peripheral surface 120 and the other side surface 140 and the outer peripheral surface 120 are both connected by the curved surfaces 170 and 180. Yes.

  Also in the seal ring 100 according to the present embodiment configured as described above, the same function and effect as those of the first embodiment can be obtained. In the case of the seal ring 100 according to the present embodiment, the lips 150a, 150b, 150c, 160a, 160b, and 160c provided on the side surfaces 130 and 140 on both sides are concentric with the side surfaces 130 and 140, respectively. A plurality of them are provided. Thus, the fact that each lip 150a, 150b, 150c, 160a, 160b, 160c can prevent the oil from being squeezed outward in the radial direction and the oil can be held between the lips. Thus, oil leakage can be suppressed synergistically. Moreover, since oil is hold | maintained between lips, there also exists an effect which can suppress sliding wear. Since the cross-sectional area of the seal ring 100 can be made smaller in the first embodiment, the first embodiment is more advantageous in terms of space.

(Other)
In the above embodiment, the case where the notched portion 220 is provided only in the first member 200 and the seal ring 100 is attached to the notched portion 220 is shown, but the second member 300 side is similarly cut. It is also possible to install the seal ring 100 in the space formed by the notch-like portions provided on both sides by providing the notch-like portions.

DESCRIPTION OF SYMBOLS 100 Seal ring 110 Inner peripheral surface 120 Outer peripheral surface 130,140 Side surface 150,160,150a, 150b, 150c, 160a, 160b, 160c Lip 151,161 Inclined part 161,162 Inclined part 170,180 Curved surface 200 First member 210 Passage 220 Notch 221 End face 222 Cylindrical face 230 Curved face 300 Second member 310 Passage 320 End face R Passage α, β Inclination angle

Claims (5)

The second member is in close contact with the planar end surface of the first member so as to surround the opening of the passage of the fluid to be sealed formed in the first member, and is opposed to the planar end surface of the second member. The gap between the end surface of the first member and the end surface of the second member is sealed in a state of surrounding the passage of the fluid to be sealed by closely contacting the opening of the passage of the fluid to be sealed formed in In an annular and rubbery elastic seal ring,
The inner peripheral surface and the outer peripheral surface are each configured in a cylindrical surface shape, and the side surfaces on both sides are each configured in a planar shape,
The side lip on both sides is provided with annular lips that incline so as to approach the plane part after inclining away from the plane part from the radially inner side to the outer side,
These lips are inclined so that the inclination of the inclined portion inclined toward the outer side from the radial portion toward the outer side in the radial direction is closer to the flat portion from the inner side toward the outer side in the radial direction. A seal ring, wherein the seal ring is designed to be larger than a gradient of the inclined portion with respect to the plane portion.   2. The seal ring according to claim 1, wherein the lip provided on each of the side surfaces on both sides is provided at an end portion on the inner peripheral surface side of each side surface.   The seal ring according to claim 1, wherein a plurality of the lips provided on the side surfaces on both sides are provided concentrically with respect to each side surface.   4. The seal according to claim 3, wherein the lip on the innermost peripheral surface side among the plurality of lips provided on the side surfaces on both sides is provided on an end portion on the inner peripheral surface side in each side surface. ring. The first member is provided with an annular notch along the opening of the passage, and the notch has a planar end surface and a cylindrical surface,
The one of the side surfaces on both sides is designed to be in close contact with the planar end surface of the notch-shaped portion, and the outer peripheral surface is designed to be in close contact with the cylindrical surface of the notch-shaped portion. The seal ring according to 1, 2, 3, or 4.

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