Sealing device

Abstract

Provided is a sealing device capable of being stably sealed.　A sealing device 1, comprising: a core metal 4; an outer peripheral seal part 7 in which the core metal 4 is inserted and arranged and which seals between a housing 2 and the core metal 4; a lip seal part 8 for sealing between a rotary shaft 3 and the core metal 4; and a backup ring 6 for backing up the lip seal part 8, wherein a space S1 is provided in at least one of a site of contact between the backup ring 6 and the outer peripheral seal part 7, a site of contact between the backup ring 6 and the lip seal part 7, and a site of contact between the backup ring 6 and the core metal 4.

Description

sealing device

[0001] The present invention relates to a sealing device, for example, a sealing device for sealing a rotating shaft.

[0002] A sealing device for sealing a rotating shaft is used by being mounted between a housing of a fluid equipment and a rotating shaft that is disposed so as to pass through the housing. Among such sealing devices, there is known one that is applied to a compressor and has a lip member that is pressed against the rotating shaft by the pressure of the sealed fluid.

[0003] For example, the sealing device shown in Patent Document 1 includes an internal pressure side lip seal, an internal pressure side support plate, an atmosphere side lip seal, and an atmosphere side support plate, arranged in this order from the sealed fluid side to the atmosphere side. The internal pressure side lip seal is fixed to a metal case having a C-shaped cross section by vulcanization adhesion. The internal pressure side support plate, the atmosphere side lip seal, and the atmosphere side support plate are sandwiched and held at both ends of the case. The case is attached to a housing.

[0004] The internal pressure side lip seal has a fixed part into which a part of the case is inserted, and a movable part extending from the fixed part to the inner diameter side. The fixed part seals between the case and the housing and between the case and the internal pressure side support plate. The internal pressure side support plate holds the movable part in a position that allows it to slide against the rotating shaft.

[0005] The atmosphere-side lip seal has a fixed part sandwiched between an internal pressure-side support plate and an atmosphere-side support plate, and a movable part extending from the fixed part toward the inner diameter. The fixed part seals the gap between the internal pressure-side support plate and the atmosphere-side support plate. The atmosphere-side support plate holds the movable part in a position that allows it to slide against the rotating shaft.

[0006] JP 2009-24541 A (page 5, Figure 2)

[0007] In the sealing device of Patent Document 1, the movable part of each lip seal is pressed against the rotating shaft by the pressure of the heat transfer medium inside the compressor, making it easier to maintain a sealed state with the rotating shaft even when the pressure of the heat transfer medium increases. Also, each lip seal elastically deforms to allow tilting of the rotating shaft, making it easier to maintain a sliding state between the movable part and the rotating shaft.

[0008] However, in a sealing device such as that described in Patent Document 1, the heat transfer medium may permeate the lip member and flow into the gap between the case and the lip member, or into gaps that occur between the internal pressure side support plate and the atmosphere side support plate due to elastic deformation of the atmosphere side lip seal. If this heat transfer medium changes state and vaporizes, a force acts on the lip member in a direction that causes it to slip out, which could cause the lip member to slip out of the case.

[0009] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a sealing device that can provide stable sealing.

[0010] To solve the above problems, the sealing device of the present invention includes a mandrel, an outer circumferential seal portion into which the mandrel is inserted and which seals between a housing and the mandrel, a lip seal portion which seals between a rotating shaft and the mandrel, and a backup ring which backs up the lip seal portion, wherein a space is provided in at least one of the contact points between the backup ring and the outer circumferential seal portion, the contact points between the backup ring and the lip seal portion, and the contact points between the backup ring and the mandrel. This prevents the sealed fluid from entering through these gaps because at least one of the outer circumferential seal portion and the lip seal portion is in contact with the backup ring. Furthermore, the space ensures a large volume through which the sealed fluid that has entered the outer circumferential seal portion or the lip seal portion can flow. Therefore, even if a foaming sealed fluid is used, the lip seal portion can be prevented from slipping out or being damaged by foaming. These features result in stable sealing performance.

[0011] The space may be in communication with a gap on the backup ring side between the backup ring and at least one of the mandrel and the outer circumferential seal portion, whereby the sealed fluid can be quickly introduced into the space through the gap on the backup ring side.

[0012] The space may be in communication with a gap on the lip seal portion side between the lip seal portion and at least one of the mandrel and the outer circumferential seal portion, whereby the sealed fluid can be quickly introduced into the space through the gap on the lip seal portion side.

[0013] The outer circumferential seal portion and the lip seal portion may be attached to the mandrel in a sealed state, thereby preventing the sealed fluid from entering a gap between the outer circumferential seal portion or the lip seal portion and the mandrel, or from entering through this gap.

[0014] The outer circumferential seal portion and the lip seal portion may be integrally molded, which provides more stable sealing.

[0015] The space may be connected to the outside, whereby the sealed fluid that has flowed into the space can be released to the outside.

[0016] The space may have a radially penetrating portion that penetrates the backup ring in the radial direction, whereby the sealed fluid that has entered the outer circumferential seal portion or the lip seal portion can be stably released to the outside with a simple structure.

[0017] The radial through portion may be a groove that is open toward the side opposite to the sealed fluid, thereby making it easier for the sealed fluid to escape in the direction away from the lip seal portion.

[0018] The space may have an axial through portion that penetrates the backup ring in the axial direction and communicates with the radial through portion, and the axial through portion may be a groove that opens toward the outer diameter side. This allows the sealed fluid that has entered the outer circumferential seal portion or the lip seal portion to be guided to the radial through portion, allowing the sealed fluid to escape to the outside more smoothly.

[0019] The radial through-portion may be a groove that is open toward the sealed fluid side, thereby enabling the sealed fluid that has entered the outer circumferential seal portion or the lip seal portion to quickly escape to the outside.

[0020] A plurality of the radial through-portions may be provided in the circumferential direction, whereby the sealed fluid that has entered the outer circumferential seal portion or the lip seal portion can be stably released to the outside.

[0021] FIG. 1 is a cross-sectional view showing a state in which a sealing device of a first embodiment according to the present invention is mounted to fluid equipment. FIG. 2 is a view for explaining a peripheral seal portion and a lip seal portion hermetically attached to a mandrel of the first embodiment. FIG. 3 is a view of a backup ring of the first embodiment as viewed from the axial direction opposite to the sealed fluid side. FIG. 4 is a cross-sectional view of the sealing device of the first embodiment. FIG. 5 is a cross-sectional view of a sealing device of a second embodiment according to the present invention. FIG. 6 is a cross-sectional view of a sealing device of a third embodiment according to the present invention. FIG. 7 is a cross-sectional view of a sealing device of a fourth embodiment according to the present invention. FIG. 8 is a cross-sectional view of a backup ring of the fourth embodiment according to the present invention as viewed from the axial direction opposite to the sealed fluid side. FIG. 9 is a cross-sectional view of a sealing device of a fifth embodiment according to the present invention. FIG. 10 is a cross-sectional view of a backup ring of a sixth embodiment according to the present invention as viewed from the axial direction opposite to the sealed fluid side. FIG. 11 is a cross-sectional view of a backup ring of a seventh embodiment according to the present invention as viewed from the axial direction opposite to the sealed fluid side. FIG. 12 is a cross-sectional view of a sealing device of a seventh embodiment according to the present invention as viewed from the axial direction opposite to the sealed fluid side. Fig. 13 is a view of a backup ring of Example 13 as seen from the axial direction side of the sealed fluid. Fig. 14 is a cross-sectional view of a sealing device of Example 14 according to the present invention. Fig. 15 is a cross-sectional view of a sealing device of Example 16 according to the present invention. Fig. 16 is a cross-sectional view of a backup ring of Example 17 according to the present invention as seen from the axial direction side opposite to the sealed fluid. Fig. 17 is a cross-sectional view of a seal member of a modified example.

[0022] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sealing device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0023] A sealing device according to a first embodiment will be described with reference to Fig. 1 to Fig. 4. In the following description, the left and right sides of the sealing device as viewed from the front side of Fig. 1 will be referred to as the left and right sides.

[0024] 1, a sealing device 1 of this embodiment is disposed between a housing 2 and a rotary shaft 3 of a compressor, which is a rotary machine, and seals between a low-pressure internal space F1 and a high-pressure internal space F2, which has a higher pressure than the low-pressure internal space F1. As a result, the sealing device 1 prevents the sealed fluid from moving from the high-pressure internal space F2 to the low-pressure internal space F1, and maintains a pressure difference between the low-pressure internal space F1 and the high-pressure internal space F2. A heat transfer medium, more specifically, a carbon dioxide heat transfer medium or oil, which is a sealed fluid, flows into the low-pressure internal space F1 and the high-pressure internal space F2.

[0025] The sealing device 1 includes a mandrel 4 , a seal member 5 , and a backup ring 6 .

[0026] In this embodiment, the object is used as a reference, and the side to the left of the object in the axial direction is the side opposite to the sealed fluid, and the side to the right of the object in the axial direction is the sealed fluid side. Specifically, if the object is the seal member 5, the backup ring 6 is located on the side opposite to the sealed fluid side of the seal member 5. Similarly, if the object is the backup ring 6, the lip seal portion 8 of the seal member 5 is located on the side closer to the sealed fluid than the backup ring 6. The low-pressure internal space F1 is the outside of the present invention. The side opposite to the sealed fluid side is the back side of the present invention.

[0027] Unless otherwise specified, the axial direction, radial direction, and circumferential direction of the rotating shaft 3 will be used as reference directions.

[0028] The mandrel 4 is made of a metal material and is formed in an annular shape with a U-shaped cross section. The mandrel 4 has a cylindrical portion 40 extending in the axial direction, an inward rear flange portion 41 extending radially inward from the left axial end of the cylindrical portion 40, and an inward front flange portion 42 extending radially inward from the right axial end of the cylindrical portion 40. The mandrel 4 has a function of holding the backup ring 6. The mandrel 4 may be made of resin, and the material may be changed as appropriate.

[0029] The cylindrical portion 40 has a thick plate portion that is connected to the front flange portion 42 and extends to the left while maintaining approximately the same thickness, i.e., radial length, a tapered plate portion that extends to the left from the left end of the thick plate portion while reducing in thickness, and a thin plate portion that extends to the left from the left end of the tapered plate portion while maintaining approximately the same thickness and connects to the rear flange portion 41.

[0030] 2, in the core 4A before assembly, the thin plate portion of the tubular portion 40A extends linearly further to the left than in the state in Fig. 1, and the rear flange portion 41 is not yet formed. When the core 4A is crimped, the tubular portion 40A is plastically deformed so that the left end portion 41A of the tubular portion 40A becomes approximately parallel to the front flange portion 42, and the left end portion 41A of the tubular portion 40A becomes the rear flange portion 41.

[0031] Returning to Figure 1, the seal member 5 is made of H-NBR, i.e., hydrogenated nitrile rubber, and is formed in a cylindrical shape with an upside-down J-shaped cross section. In this specification, the portion of the seal member 5 that is fixed to the inserted mandrel 4 by vulcanization bonding is called the outer circumferential seal portion 7, and the portion extending from the outer circumferential seal portion 7 toward the inner diameter is called the lip seal portion 8, and the outer circumferential seal portion 7 and the lip seal portion 8 are formed integrally. The outer circumferential seal portion 7 is attached to the mandrel 4 in a sealed state. Furthermore, the lip seal portion 8 is attached to the mandrel 4 in a sealed state via the outer circumferential seal portion 7.

[0032] In this embodiment, for the sake of convenience, the boundary between the outer seal portion 7 and the lip seal portion 8 is shown by the dashed line, more specifically, the inner diameter end of the radially extending portion 71 described later, but these boundaries may be changed as appropriate.

[0033] The material of the seal member 5 may be changed as needed, but rubber is preferred because of its excellent sealing properties and the ability of the lip seal portion to follow the rotation axis. Among rubbers, synthetic rubber is more preferred. Furthermore, as long as the outer circumferential seal portion and the lip seal portion are hermetically attached to the mandrel, the attachment method is not limited to vulcanization bonding and may be changed as needed.

[0034] The outer seal portion 7 extends from the left end face of the rear flange portion 41 to the outer surface of the tubular portion 40 , the right end face, inner surface, and left end face of the front flange portion 42 , and to the left end of the inner surface of the tubular portion 40 .

[0035] The outer seal portion 7 has an annular bulge 70 that protrudes outward from the portion that covers the outer peripheral surface of the cylindrical portion 40. The bulge 70 seals the gap between the housing 2 and the mandrel 4 when the outer seal portion 7 is fitted into the housing 2 together with the mandrel 4. In other words, the outer seal portion 7 functions as a so-called secondary seal.

[0036] In this embodiment, the core bar 4 and the seal member 5 are configured to be directly attached to the housing 2, but this is not limiting and they may be attached to the housing 2 via other members. In other words, being attached to the housing in the present invention means that they are directly or indirectly attached to the housing.

[0037] Here, in the outer circumferential seal portion 7, a portion that covers the left end face of the front flange portion 42 and extends in the radial direction is referred to as a radially extending portion 71. In addition, a portion that extends from the outer diameter end of the radially extending portion 71 to the axially left side and covers the inner circumferential surface of the tubular portion 40 is referred to as an axially extending portion 72.

[0038] 2, the radially extending portion 71 is provided with a protrusion 73 having a triangular cross section and an annular shape that protrudes from the radial center toward the side opposite to the sealed fluid. The protrusion 73 is formed at the radial center of the core 4, more specifically, at approximately the same radial position as the radial center of the front flange portion 42.

[0039] 1 , the lip seal portion 8 has a base portion 80 that extends radially inward from the inner diameter end of the radially extending portion 71, and a lip portion 81 that extends and curves rightward and inward from the inner diameter end of the base portion 80. The inner diameter end of the radially extending portion 71 is a portion that is located on the same plane as the inner diameter end face of the portion of the outer circumferential seal portion 7 that covers the right end face of the front flange portion 42.

[0040] In the lip seal portion 8, the left end face of the base 80, i.e., the end face located on the low-pressure space F1 side, and the end face of the lip portion 81 that is continuous with this end face, are defined as end faces opposite the sealed fluid side. Also, in the lip seal portion 8, the right end face of the base 80 and the end face of the lip portion 81 that is continuous with this end face are defined as end faces on the sealed fluid side.

[0041] The end face of the base 80 of the lip seal portion 8 on the side opposite to the sealed fluid is substantially flush with the left end face (see FIGS. 2 and 4) of the outer circumferential seal portion 7 that is located radially inward of the protrusion 73 of the radially extending portion 71. Note that the end face of the base 80 on the side opposite to the sealed fluid does not have to be flush with the left end face of the radially extending portion 71, and may be located at a different position in the axial direction.

[0042] 1 and 4, the lip portion 81 is elastically deformed so that its inner diameter end expands toward the outer diameter side by the inserted rotating shaft 3. Due to this elastic deformation, the inner diameter end of the end face of the lip portion 81 opposite to the sealed fluid side is pressed against the rotating shaft 3 so as to be in sliding contact with the rotating shaft 3.

[0043] The lip portion 81 extends in the left-right direction with the inner diameter end of its end face on the sealed fluid side slightly inclined with respect to the axis of the rotating shaft 3. The lip portion 81 is pressed toward the rotating shaft 3 by fluid pressure acting on the end face on the sealed fluid side. As a result, the force with which the end face of the lip portion 81 opposite the sealed fluid side is pressed against the rotating shaft 3 is increased.

[0044] As described above, the lip seal portion 8 seals the gap between the rotating shaft 3 and the mandrel 4 together with the outer circumferential seal portion 7. The lip seal portion of the present invention may be any seal that contributes to sealing the gap between the rotating shaft and the mandrel. This also applies to the outer circumferential seal portion of the present invention.

[0045] The backup ring 6 is made of a metal material such as steel and has an annular shape with an inverted L-shape in cross section. The backup ring 6 is positioned radially inward of the cylindrical portion 40 of the mandrel 4 and is sandwiched between the rear flange portion 41 and the front flange portion 42 of the mandrel 4.

[0046] The backup ring 6 is disposed on the side away from the sealed fluid relative to the radially extending portion 71 of the outer circumferential seal portion 7 and the lip seal portion 8. The radially extending portion 71 provides a seal between the backup ring 6 and the mandrel 4.

[0047] Furthermore, the backup ring 6, which is clamped by the core metal 4, maintains the position of the lip portion 81 of the lip seal portion 8 while preventing the lip seal portion 8 from elastically deforming and tilting toward the side away from the sealed fluid, by means of its base portion 60 and inclined portion 61.

[0048] The backup ring 6 has a base portion 60 extending in the radial direction, an inclined portion 61 extending from the inner diameter end of the base portion 60 to the right and inward at an angle, and an axially extending portion 62 protruding from the outer diameter end of the base portion 60 to the left, i.e., in the direction opposite to the sealed fluid side. The backup ring 6 may be made of resin, and the material may be changed as appropriate.

[0049] The base 60 has a rectangular cross section. More specifically, the base 60 has a right end face 60a extending in the radial direction, a left end face 60b disposed to the left of the right end face 60a, i.e., on the opposite side to the sealed fluid side, a curved surface 60c extending from the outer diameter end of the right end face 60a while curving toward the left in the axial direction and toward the outer diameter side in the radial direction, and an outer peripheral surface 60d extending from the left end of the curved surface 60c toward the left in the axial direction. The curved surface 60c is formed in a quarter-circular arc shape that protrudes toward the outer diameter side and rightward.

[0050] The thickness of the base 60, that is, the length in the axial direction from the right end face 60a to the left end face 60b, is substantially constant along the radial direction.

[0051] The axially extending portion 62 is formed in a cross-sectional shape consisting of a quarter-circular portion that protrudes inward and to the left and a rectangular portion that extends from the outer diameter side to the outer diameter side, and its outer diameter end protrudes outward beyond the base 60. The axially extending portion 62 has a curved surface 62a that extends axially left and radially outward from the outer diameter end of the left end face 60b of the base 60, and a left end face 62b that extends radially outward from the outer diameter end of the curved surface 62a. The curved surface 62a is formed in a quarter-circular arc shape that protrudes inward and to the left.

[0052] 1 and 3, the backup ring 6 is formed with eight radial through-portions 63 and eight axial through-portions 64. The eight radial through-portions 63 are provided at contact areas between the axially extending portions 62 of the backup ring 6 and the rear flange portion 41 of the mandrel 4. The eight axial through-portions 64 are provided at contact areas between the base portion 60 of the backup ring 6 and the radially extending portions 71 and 72 of the outer circumferential seal portion 7. These radial through-portions 63 and axial through-portions 64 are evenly spaced. Each of the radial through-portions 63 and each of the axial through-portions 64 constitutes a space S1 of the present invention.

[0053] The radial through-portion 63 is recessed axially rightward from the curved surface 62a and the left end surface 62b of the axially extending portion 62, and is a groove that opens axially leftward, in other words, toward the rear flange portion 41. The radial through-portion 63 extends linearly in the radial direction, penetrating the axially extending portion 62, and is open to both radial sides. The radial through-portion 63 communicates with the low-pressure internal space F1. In other words, the space S1 is connected to the low-pressure internal space F1.

[0054] The radially extending bottom surface of the radially penetrating portion 63 is flat, but is not limited to this and may be curved, V-shaped, or otherwise modified as appropriate. The same applies to the axially penetrating portion 64.

[0055] The axial through-portion 64 is a groove recessed from the curved surface 60c and the outer peripheral surface 60d (see FIG. 1) of the base portion 60 toward the inner diameter side, and is open toward the outer diameter side, in other words, toward the axially extending portion 72. The axial through-portion 64 extends linearly in the axial direction, penetrating the base portion 60, and is open toward both axial sides. The axial through-portion 64 is connected to the outer diameter side portion of the radial through-portion 63.

[0056] The base 60 of the backup ring 6 and the radially extending portion 71 and axially extending portion 72 of the outer peripheral seal portion 7 define a gap G1 that has a triangular cross section and an annular shape that widens toward the left in the axial direction. Each axial through-portion 64 communicates with the gap G1. Hereinafter, the gap G1 may also be referred to as the "right-side gap G1."

[0057] Additionally, the base portion 60 and axially extending portion 62 of the backup ring 6, the cylindrical portion 40 and rear flange portion 41 of the mandrel 4, and the axially extending portion 72 of the outer circumferential seal portion 7 define an annular gap G2. Each of the radial through-portions 63 and each of the axial through-portions 64 communicates with the gap G2. Hereinafter, the gap G2 may also be referred to as the "left-side gap G2."

[0058] The right gap G1 and the left gap G2 are in communication with each other through the radial through-portions 63 and the axial through-portions 64 .

[0059] The gaps G1 and G2 are primarily defined by the core metal 4 and / or the outer circumferential seal portion 7, and the backup ring 6, and therefore correspond to the gaps on the backup ring side in the present invention.

[0060] Next, a description will be given of the assembly of the sealing device 1. In this description, it is assumed that the core 4 and the outer circumferential seal portion 7 of the seal member 5 have already been vulcanization bonded, and a description of this vulcanization bonding will be omitted.

[0061] Referring to Figure 2, by placing a backup ring 6 on the inner diameter side of the cylindrical portion 40A of the core 4A before assembly and then crimping the core 4A, the sealing device 1 can be assembled, in which the seal member 5 and the backup ring 6 are held by the core 4.

[0062] In detail, the crimping of the core bar 4A is performed by pressing the left end portion 41A of the tubular portion 40A by a pressure device (not shown) so that the left end portion 41A is bent approximately 45 degrees toward the inner diameter side, starting from the point where the tubular portion 40A continues to the other portions.

[0063] Next, the left end 41A of the cylindrical portion 40A is pressed by a pressure device so as to bend it further by approximately 50 degrees from the position where it was deformed by the first pressing, as shown schematically by the two-dot chain line in FIG.

[0064] This is possible because the axial extension portion 62 of the backup ring 6 protrudes to the left of the base portion 60, and the tip of the left end portion 41A of the pressed tubular portion 40A can advance further inward than the axial extension portion 62.

[0065] In this way, the sealing device 1 can bend the tubular portion 40A by approximately 95 degrees from the state before crimping while preventing tilting or deformation of the backup ring 6, so that the core bar 4 can be sufficiently crimped to firmly fix the backup ring 6.

[0066] Furthermore, the left end 41A of the cylindrical portion 40A is pressed against the curved surface 62a of the axially extending portion 62, so that unintended deformation due to contact with a corner is unlikely to occur.

[0067] The backup ring may not necessarily have the axially extending portion 62, but it is preferable that the axially extending portion 62 be formed in order to be able to sufficiently crimp the mandrel 4 as described above. The cross-sectional shape of the axially extending portion may be rectangular or may be changed as appropriate, but a cross-sectional shape with a curved surface such as the curved surface 62a is preferable in order to prevent corner contact.

[0068] Thereafter, the second pressure is released, causing the left end portion 41A of the cylindrical portion 40A that had been pressed to elastically return slightly, forming a rear flange portion 41 that is approximately perpendicular to the cylindrical portion 40, as shown in Figure 4.

[0069] As the uncrimped core 4A is crimped, the backup ring 6 is pressed in toward the right in the axial direction as shown by the white arrow in FIG.

[0070] The base 60 of the backup ring 6 bites into the axially extending portion 72 of the seal member 5, with the right corner portion on the outer diameter side where the curved surface 60c is formed, elastically deforming part of the axially extending portion 72. The backup ring 6 is aligned by the resilient force received from this elastically deformed axially extending portion 72. This allows the gaps G1 and G2 to be stably formed.

[0071] In addition, since the curved surface 60c of the base 60 of the backup ring 6 is pressed against the axial extension portion 72, damage such as scratches to the axial extension portion 72 due to corner contact is prevented, while the backup ring 6 can be easily pressed into the axial extension portion 72.

[0072] The backup ring 6 is pressed through the left end portion 41A, and is press-fitted while its base portion 60 is elastically deformed so as to crush the protrusion 73.

[0073] A detailed description will be given of the elastic deformation of this protrusion 73. The left end portion 41A pressed by the pressing device has a portion corresponding to the outer diameter side of the right end face of the rear flange portion 41 after assembly pressed against the left end face 62b of the axially extending portion 62. The left end face 62b against which the left end portion 41A is pressed serves as a point of force, and the portion of the base 60 where it abuts against the protrusion 73 serves as a point of action.

[0074] As described above, since the protrusion 73 is formed at approximately the same radial position as the radial center of the front flange portion 42, the distance from the force point to the action point is shorter and the moment is smaller than when the protrusion is located on the inner diameter side of the radial center of the front flange portion 42.

[0075] In this way, in the sealing device 1, the distance from the point of force to the point of action is short and the moment is small when the core bar 4 is tightened, so the influence of the elastic force from the protrusion 73 is smaller than when the distance is long and the moment is large. This allows the sealing device 1 to be assembled stably.

[0076] Furthermore, compared to a structure such as that described in Patent Document 1, in which a separate lip seal is interposed between the backup ring and the inward flange portion, the distance from the point of force to the point of action is shorter and the moment is smaller.

[0077] 4, even when the pressure on the left end portion 41A is released, that is, in the assembled state, the sealing device 1 maintains a state in which the protrusion 73 is elastically deformed as if crushed by the rear flange portion 41 and the front flange portion 42 of the core 4, and a state in which the base portion 60 is pressed against the protrusion 73 and the radially extending portion 71. In addition, a state in which the gaps G1, G2 and the space S1 are in communication with the low-pressure internal space F1 is also maintained.

[0078] As explained above, in the sealing device 1 of this embodiment, the peripheral seal portion 7 and the lip seal portion 8 are in contact with the backup ring 6, so that the intrusion of the sealed fluid through the gap between them can be prevented. In addition, the space S1 ensures a large volume into which the sealed fluid that has infiltrated the peripheral seal portion 7 or the lip seal portion 8 can flow. Therefore, even if the sealed fluid is a foamable carbon dioxide heat transfer medium that foams when it changes state from liquid to gas, the lip seal portion 8 can be prevented from slipping out and the peripheral seal portion 7 or the lip seal portion 8 can be prevented from being damaged by foaming of the sealed fluid. These factors contribute to stable sealing performance.

[0079] Furthermore, a portion of the outer circumferential seal portion 7 faces the gaps G1, G2 on the backup ring 6 side. As a result, the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 is easily guided into the gaps G1, G2. In the sealing device 1, the space S1 communicates with the gaps G1, G2, so the sealed fluid can be quickly guided into the space S1 through the gaps G1, G2.

[0080] Furthermore, since the sealing device 1 has the outer circumferential seal portion 7 and the lip seal portion 8 attached to the core metal 4 in a sealed manner, it is possible to prevent the sealed fluid from entering the gap between the outer circumferential seal portion 7 or the lip seal portion 8 and the core metal 4, or from entering the sealed fluid through this gap.

[0081] Furthermore, since the sealing device 1 has the outer circumferential seal portion 7 and the lip seal portion 8 integrally molded, the sealing performance is more stable.

[0082] Furthermore, in the sealing device 1, the space S1 communicates with the low-pressure internal space F1, so that the sealed fluid that has flowed into the space S1 can escape to the low-pressure internal space F1.

[0083] Furthermore, in the sealing device 1, the radial through-portion 63 and the axial through-portion 64 that form the space S1 are provided in the backup ring 6. This allows the sealing device 1 to easily provide the space S1.

[0084] Furthermore, since the space S1 has a radial through-hole 63 formed in the backup ring 6, the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 can be stably released into the low-pressure inner space F1 with a simple structure.

[0085] Furthermore, the radial through portion 63 is a groove that is open toward the side opposite to the sealed fluid, so that the sealed fluid can easily escape in the direction opposite to the lip seal portion 8 .

[0086] In addition, since the axial through-portion 64 is a groove that opens toward the outer diameter side, the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 can be easily guided to the axial through-portion 64. Furthermore, since the axial through-portion 64 communicates with the radial through-portion 63, the sealed fluid that has flowed into the axial through-portion 64 can be easily guided to the radial through-portion 63. As a result, the sealed fluid can be more smoothly released into the low-pressure internal space F1.

[0087] In this embodiment, the structure in which the radial through-holes 63 and the axial through-holes 64 are provided has been described, but the present invention is not limited to this, and only the radial through-holes 63 may be provided. Even with this configuration, the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 can be released into the low-pressure internal space F1. However, from the viewpoint of securing an area facing the outer circumferential seal portion 7 or the lip seal portion 8 and easily improving the efficiency of guiding the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 into the space, it is preferable to provide the radial through-holes 63 and the axial through-holes 64.

[0088] Furthermore, since the radial through-holes 63 are provided in multiple locations in the circumferential direction, the area facing the outer circumferential seal portion 7 and the lip seal portion 8 is secured, thereby increasing the efficiency of guiding the sealed fluid that has entered the outer circumferential seal portion 7 and the lip seal portion 8 to the space S1, and the sealed fluid that has entered the outer circumferential seal portion 7 and the lip seal portion 8 can be stably released into the low-pressure internal space F1. The same applies to the axial through-holes 64 that are provided in multiple locations in the circumferential direction.

[0089] Although only one radial through-portion 63 may be provided, it is preferable to provide a plurality of radial through-portions 63 from the viewpoint of ensuring an area facing the outer circumferential seal portion 7 and the lip seal portion 8 and from the viewpoint of facilitating the escape of the sealed fluid to the low-pressure internal space F1. The same applies to the plurality of axial through-portions 64 provided in the circumferential direction.

[0090] Furthermore, the right gap G1 widens toward the left in the axial direction, making it easier to guide the sealed fluid into the axial through-portion 64.

[0091] In addition, the right gap G1 is annular, which facilitates dispersion of the sealed fluid among the plurality of axial through-portions 64. Furthermore, the sealed fluid that has flowed into a position other than the position where the axial through-portions 64 are formed can be guided to one of the axial through-portions 64.

[0092] Although the gap G1 on the right side does not have to be formed, it is preferable that it be formed from the viewpoint of ensuring an area facing the outer seal portion 7 and the lip seal portion 8, and from the viewpoint of making it easier for the sealed fluid to escape into the low-pressure internal space F1.

[0093] Furthermore, since the left gap G2 is annular, the sealed fluid can be easily dispersed among the plurality of radial through-holes 63. This allows the sealed fluid to escape to the low-pressure internal space F1 more stably.

[0094] Although the gap G2 on the left side does not have to be formed, it is preferable that it be formed from the viewpoint of ensuring an area facing the outer seal portion 7 and the lip seal portion 8, and from the viewpoint of making it easier for the sealed fluid to escape into the low-pressure internal space F1.

[0095] Furthermore, in the sealing device 1, the radial through-portion 63 and the axial through-portion 64 communicate with the gaps G1, G2, so the volume of the area connected to the space S1 is larger than in a structure in which the gaps G1, G2 are not formed. This makes it easier to tolerate changes in the state of the sealed fluid that has passed through the outer circumferential seal portion 7 and the lip seal portion 8 while ensuring the area facing the outer circumferential seal portion 7 and the lip seal portion 8.

[0096] In this embodiment, the radial through portion 63 and the axial through portion 64 are described as being directly connected to each other, but this is not limited to this, and they may be connected to each other through the gap G2 on the left side.

[0097] Furthermore, although the gaps G1 and G2 in this embodiment are configured to be divided in the axial direction by the axially extending portion 72 of the seal member 5 and the base portion 60 of the backup ring 6 pressed against it, they may be formed as a continuous gap by, for example, making the axially extending portion 72 non-contact with the backup ring 6. On the other hand, from the viewpoint of being able to stably form the gaps G1 and G2, a structure in which the axially extending portion 72 and the base portion 60 are in contact with each other, as in this embodiment, is preferable.

[0098] Furthermore, the outer seal portion 7 and the lip seal portion 8 are made of hydrogenated nitrile rubber, and the sealed fluid is a carbon dioxide heat transfer medium, so that the outer seal portion 7 and the lip seal portion 8 can be kept highly sealed while preventing damage.

[0099] Furthermore, since the seal member 5 is made of rubber, it can reduce the environmental impact compared to a lip member made of PTFE.

[0100] Furthermore, in the sealing device 1, the core 4 that holds the lip seal portion 8 supports the lip seal portion 8 from its back side via the backup ring 6, so that the backup ring 6 is less likely to shift out of position, resulting in stable sealing performance.

[0101] Furthermore, in the sealing device 1, a radially extending portion 71 of the outer circumferential seal portion 7 is interposed between the backup ring 6 and the mandrel 4 in the axial direction, and a part of an axially extending portion 72 of the outer circumferential seal portion 7 is interposed between the backup ring 6 and the mandrel 4 in the radial direction. This prevents the backup ring 6 from rattling.

[0102] Note that either the radially extending portion 71 or the axially extending portion 72 may be interposed between the backup ring 6 and the mandrel 4, or neither may be interposed. In other words, the backup ring and the mandrel may be in direct contact with each other.

[0103] On the other hand, from the viewpoint of preventing axial or radial rattles, it is preferable that either the radial extension portion 71 or the axial extension portion 72 be interposed.

[0104] Furthermore, from the viewpoint of being able to reduce both axial and radial rattles, a structure in which the radial extension portion 71 and the axial extension portion 72 are interposed between the backup ring 6 and the core bar 4, as in this embodiment, is preferable.

[0105] Furthermore, in the sealing device 1, the protrusions 73 provided on the outer circumferential seal portion 7 are held in an elastically deformed state, and the elastic force acts to press the backup ring 6 against the rear flange portion 41 of the mandrel 4. This prevents the backup ring 6 from moving in the axial direction.

[0106] Furthermore, since the protrusion 73 is annular, the sealing performance between the backup ring 6 and the outer peripheral seal portion 7 is high.

[0107] The projections are not limited to being annular, and may have a trapezoidal cross-sectional shape, may be C-shaped when viewed in the axial direction, or may have multiple hemispherical projections, and the shape, number, and arrangement may be changed as appropriate. Although such a structure can prevent axial movement of the backup ring 6, annular projections as in this embodiment are preferable from the standpoint of being able to prevent axial movement of the backup ring 6 at any position in the circumferential direction and from the standpoint of sealing performance.

[0108] Next, a sealing device according to a second embodiment will be described with reference to Fig. 5. Note that the same components as those shown in the first embodiment are designated by the same reference numerals and redundant description will be omitted.

[0109] 5, in a sealing device 201 of the second embodiment, a rubber membrane material 209 having a cylindrical J-shaped cross section rotated 90 degrees counterclockwise is fixed to the rear flange portion 41 of the mandrel 4. The material of the membrane material 209 may be changed as appropriate.

[0110] The membrane material 209 is fixed in a cantilevered state with its left axial end supported on the inner diameter end of the rear flange portion 41. In addition, the membrane material 209 has its right axial end abutting against the left end surface 60b of the base 60 of the backup ring 6. In other words, the membrane material 209 seals the space S1 and the low-pressure internal space F1. This makes it difficult for contaminants floating in the low-pressure internal space F1 to flow into the space S1.

[0111] Furthermore, when the sealed fluid that has flowed into the space S1 expands and the pressure in the space S1 exceeds a certain level, the membrane material 209 elastically deforms in the direction away from the left end surface 60b of the backup ring 6, and the space S1 communicates with the low-pressure space F1, thereby allowing the sealed fluid to escape to the low-pressure space F1.

[0112] Next, a sealing device according to a third embodiment will be described with reference to Fig. 6. Note that the same components as those shown in the first embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0113] Referring to FIG. 6 , in a sealing device 301 of the third embodiment, a radial groove 363 and a through hole 364 are formed in a backup ring 306 .

[0114] The radial groove 363 is recessed from the radial center of the left end face 362b of the axially extending portion 362 of the backup ring 306 toward the inner diameter side and from the curved surface 362a toward the right in the axial direction, and is open toward the left in the axial direction. Moreover, the radial groove 363 is open toward the inner diameter side and communicates with the low-pressure internal space F1, while the outer diameter side is closed.

[0115] The through-hole 364 passes through the outer diameter side of the base portion 360 of the backup ring 306 in the axial direction, and communicates with the right gap G1 and the radial groove portion 363 .

[0116] The sealing device 301 of this embodiment can allow the sealed fluid that has entered the outer seal portion 7 or the lip seal portion 8 to escape to the low-pressure internal space F1 through the space S3 formed by the through hole 364 and the radial groove portion 363.

[0117] In this embodiment, the right gap G1 and the low-pressure space F1 are described as being in communication with each other through the radial groove 363 and the through-hole 364, but this is not limiting, and they may be in communication with each other through a single through-hole that extends at an angle from the gap G1 toward the low-pressure space F1. In other words, the formation direction and number of through-holes may be changed as appropriate.

[0118] Furthermore, in this embodiment, a configuration has been described in which the through hole 364 is formed as an alternative to the axial through portion 64 of the first embodiment, but the present invention is not limited to this, and a radial through hole penetrating in the radial direction may be formed as an alternative to the radial through portion 63 of the first embodiment. The radial through hole may be in communication with the axial through portion 64 or the through hole 364, and may be changed as appropriate.

[0119] The left gap G2 is not in communication with the space S3. From the viewpoint of making it easier for the sealed fluid that has flowed into the gap G2 to escape to the low-pressure inner space F1, the radial through-portion 63 or the axial through-portion 64 of the first embodiment are preferable.

[0120] A sealing device according to a fourth embodiment will be described with reference to Figures 7 and 8. Note that the same components as those shown in the first embodiment are designated by the same reference numerals and redundant description will be omitted.

[0121] 7 , in a sealing device 401 of the fourth embodiment, a space S4 communicating with the low-pressure internal space F1 is formed at a contact area between a base portion 460 and an inclined portion 461 of the backup ring 406 and a radially extending portion 71 and a lip seal portion 8 of the outer circumferential seal portion 7. On the other hand, no space is formed at a contact area between an axially extending portion 462 of the backup ring 406 and a rear flange portion 41 of the mandrel 4.

[0122] The space S4 is formed by eight radial through-holes 463 (see FIG. 8).

[0123] The radial through-portion 463 is recessed from the right end face 460a and curved surface 460c of the base 460 and the right end face 461a of the inclined portion 461 to the left in the axial direction, and is open to the right in the axial direction, in other words, toward the radially extending portion 71 of the outer circumferential seal portion 7 and the lip seal portion 8. The radial through-portion 463 communicates with the gap G1 on the right side. The right end face 461a of the inclined portion 461 is an inclined surface that extends linearly from the inner diameter end of the right end face 460a of the base 460, inclined toward the outer diameter side and to the right in the axial direction, and a flat surface that extends linearly from the inner diameter end toward the inner diameter side.

[0124] The radial through-portion 463 radially penetrates the backup ring 406 and is open to both radial sides. The radial through-portion 463 communicates with the low-pressure internal space F1.

[0125] As shown in Figure 7, the radial through portion 463 has different depths, i.e., different lengths in the left-right direction, at the portion facing the curved surface 460c of the base 460, the portion facing the right end surface 460a of the base 460, and the portion facing the right end surface 461a of the inclined portion 461.

[0126] In particular, the portion formed on the inclined portion 461 is formed to a depth greater than the depth of any portion formed on the base portion 460, and becomes deeper toward the inner diameter side. This makes it possible to maintain communication between the space S4 and the low-pressure inner space F1 even when the lip portion 81 of the lip seal portion 8 is pressed against the inclined portion 461 under the pressure of the sealed fluid.

[0127] In the sealing device 401 of this embodiment, the outer circumferential seal portion 7 and the lip seal portion 8 are in contact with the backup ring 406, so that the infiltration of the sealed fluid through gaps therebetween can be prevented. In addition, the space S4 ensures a large volume into which the sealed fluid that has infiltrated the outer circumferential seal portion 7 or the lip seal portion 8 can flow. Therefore, even if the sealed fluid is a foaming carbon dioxide heat transfer medium that foams when it changes state from liquid to gas, the outer circumferential seal portion 7 and the lip seal portion 8 can be prevented from being damaged by foaming of the sealed fluid.

[0128] Furthermore, the sealing device 401 can allow the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 to escape to the low-pressure inner space F1 through the space S4.

[0129] Furthermore, since the radial through portion 463 is a groove that is open toward the sealed fluid side, i.e., toward the sealing member 5 in the axial direction, it can guide the sealed fluid that has entered the outer peripheral seal portion 7 or the lip seal portion 8 and quickly release it into the low-pressure internal space F1.

[0130] Furthermore, a portion of the seal member 5 elastically returns toward the inside of the radial through-hole 463, thereby engaging with the backup ring 406. This makes it difficult for the lip seal portion 8 to be twisted due to sliding contact with the rotating shaft 3.

[0131] Next, a sealing device according to a fifth embodiment will be described with reference to Fig. 9. Note that the same components as those shown in the first embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0132] Referring to Figure 9, in the sealing device 501 of Example 5, a space S5 communicating with the low-pressure internal space F1 is formed at the contact point between the base 560 of the backup ring 506 and the radially extending portion 71 and lip seal portion 8 of the outer circumferential seal portion 7.

[0133] The space S5 is formed by eight radial grooves 563.

[0134] The radial groove 563 is formed in the base portion 560 of the backup ring 506, and its inner diameter end is closed on the outer diameter side of the inclined portion 61. The radial groove 563 also opens toward the radially extending portion 71 of the outer circumferential seal portion 7 and the base portion 80 of the lip seal portion 8.

[0135] The sealing device 501 of this embodiment can allow the sealed fluid that has entered the outer circumferential seal portion 7 or the lip seal portion 8 to escape to the low-pressure inner space F1 through the space S5.

[0136] More specifically, when the pressure in the space S5 is below a certain level, the space S5 is not in communication with the low-pressure space F1 due to the lip portion 81 being pressed against the inclined portion 61. This makes it difficult for contaminants floating in the low-pressure space F1 to flow into the space S5.

[0137] Furthermore, when the sealed fluid that has flowed into the space S5 expands and the pressure in the space S5 exceeds a certain level, the lip seal portion 8 elastically deforms in the direction away from the backup ring 6, and the space S5 communicates with the low-pressure space F1, thereby allowing the sealed fluid to escape to the low-pressure space F1.

[0138] On the other hand, the sealing device 401 of the fourth embodiment is preferable in that it is possible to stably release the sealed fluid into the low-pressure internal space F1.

[0139] Next, a sealing device according to a sixth embodiment will be described with reference to Fig. 10. Note that the same components as those shown in the first embodiment are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0140] 10 , the backup ring 606 is formed with eight radial through-holes 63 on the side opposite to the sealed fluid side, eight axial through-holes 64, and eight radial through-holes 463 on the sealed fluid side. That is, in this embodiment, spaces are formed at the contact area between the backup ring and the mandrel, the contact area between the backup ring and the outer circumferential seal portion, and the contact area between the backup ring and the lip seal portion.

[0141] The radial through-portion 63 on the side opposite to the sealed fluid and the radial through-portion 463 on the side of the sealed fluid are formed so as to alternate in the circumferential direction, so that the formation of each portion can be prevented from affecting the other's while ensuring a sufficient depth for each portion.

[0142] With this configuration, the volume of the space can be made larger than the space S1 of the first embodiment, and the sealed fluid that has entered the outer seal portion 7 or the lip seal portion 8 can be quickly released into the low-pressure inner space F1.

[0143] The anti-sealed fluid groove and the sealed fluid groove may be formed at the same circumferential position, or the formation locations may be changed as appropriate. The sealed fluid groove may also communicate with an outer diameter groove such as the axial through-portion 64. The number of anti-sealed fluid grooves and the number of sealed fluid grooves may be different.

[0144] A sealing device according to a seventh embodiment will be described with reference to Figures 11 to 13. Note that the same components as those shown in the first embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0145] 11 , a sealing device 1001 of this embodiment is disposed between a housing 1002 and a rotating shaft 1003 of a compressor, which is a rotary machine, and seals between an outer space A and an inner space F. The outer space A is the outside of the present invention, which is in communication with the atmosphere. The inner space F is a high-pressure space into which a heat transfer medium, which is a sealed fluid having a higher pressure than the atmosphere, more specifically, a carbon dioxide heat transfer medium, flows.

[0146] The sealing device 1001 includes a lip member 1004 as a lip seal portion, a backup ring 1005 , and a case 1006 .

[0147] In this embodiment, the object is used as a reference, and the left side of the object in the axial direction is the side opposite to the sealed fluid of the present invention, and the right side of the object in the axial direction is the side opposite to the sealed fluid of the present invention. Specifically, if the object is the lip component 1004, the backup ring 1005 is located on the side opposite to the sealed fluid of the lip component 1004. Similarly, if the object is the backup ring 1005, the lip component 1004 is located on the side closer to the sealed fluid of the backup ring 1005.

[0148] The lip component 1004 is made of H-NBR, i.e., hydrogenated nitrile rubber, and is formed in a cylindrical shape with an L-shaped cross section. The lip component 1004 has a base portion 1040 extending in the radial direction, and a lip portion 1041 that extends and curves from the inner diameter end of the base portion 1040 toward the right side and the inner diameter side. Note that the material of the lip component 1004 may be changed as appropriate, but rubber is more preferable in terms of its excellent followability and sealing properties.

[0149] In the lip component 1004, the left end face of the base 1040, i.e., the end face located on the external space A side, and the end face of the lip portion 1041 that is continuous with this end face, are referred to as the end faces opposite the sealed fluid side. Also, in the lip component 1004, the right end face of the base 1040 and the end face of the lip portion 1041 that is continuous with this end face are referred to as the end faces on the sealed fluid side.

[0150] 11 and 13, the lip portion 1041 is elastically deformed so that its inner diameter end expands toward the outer diameter side by the inserted rotating shaft 1003. Due to this elastic deformation, the inner diameter end side of the end face of the lip portion 1041 on the side opposite to the sealed fluid is pressed against the rotating shaft 1003 so as to be in sliding contact with the rotating shaft 1003.

[0151] The lip portion 1041 extends in the left-right direction with the inner diameter end of its end face on the sealed fluid side slightly inclined with respect to the axis of the rotating shaft 1003. The lip portion 1041 is pressed toward the rotating shaft 1003 by fluid pressure acting on the end face on the sealed fluid side. As a result, the force with which the end face of the lip portion 1041 opposite the sealed fluid side is pressed against the rotating shaft 1003 is increased.

[0152] The backup ring 1005 is made of a metal material such as steel and is formed in a disk shape. The backup ring 1005 has a base portion 1050 extending in the radial direction, an inclined portion 1051 extending inwardly and at an angle to the right from the inner diameter end of the base portion 1050, and an inner diameter end portion 1052 extending in the radial direction from the inner diameter end of the inclined portion 1051. The backup ring 1005 may be made of resin, and the material may be changed as appropriate.

[0153] The base 1050 has a rectangular cross section. More specifically, the base 1050 has a right end face 1050a extending radially, a left end face 1050b as the end face opposite the sealed fluid side in this embodiment, which is disposed on the opposite side of the right end face 1050a from the right end face 1050a, and an outer circumferential surface 1050c extending axially leftward from the outer diameter end of the right end face 1050a and continuing to the outer diameter end of the left end face 1050b. The thickness of the base 1050, i.e., the axial length from the right end face 1050a to the left end face 1050b, is substantially constant along the radial direction.

[0154] 11 and 12 , the base 1050 is formed with eight anti-sealed fluid grooves 1053 and eight outer diameter grooves 1054 as axially penetrating portions. The eight anti-sealed fluid grooves 1053 are provided at contact portions between the base 1050 of the backup ring 1005 and the rear flange portion 1071 of the mandrel 1007. The eight outer diameter grooves 1054 are provided at contact portions between the base 1050 of the backup ring 1005 and the base 1040 of the lip component 1004 and the inclined portion 1082 of the outer peripheral seal portion 1008. The anti-sealed fluid grooves 1053 and the outer diameter grooves 1054 are evenly spaced. Note that in FIG. 12 , the anti-sealed fluid grooves 1053 are shown with a dotted pattern for clarity.

[0155] The anti-sealed fluid-side groove 1053 is recessed axially rightward from the left end face 1050b of the base 1050 and is open axially leftward. The anti-sealed fluid-side groove 1053 extends linearly in the radial direction, and its outer diameter end is radially connected to the axial left end of the outer diameter side groove 1054. The anti-sealed fluid-side groove 1053 has an inner diameter end that is closed at a position outer diameter side than the inclined portion 1051.

[0156] The bottom surface of the anti-sealed fluid side groove 1053 is a curved surface that extends radially and protrudes toward the right in the axial direction, but is not limited to this and may be a flat surface, a V-shape, or any other suitable shape. The same applies to the outer diameter side groove 1054.

[0157] The outer diameter groove 1054 is a groove that is recessed from the outer peripheral surface 1050c of the base 1050 toward the inner diameter side and is open toward the outer diameter side. In addition, the outer diameter groove 1054 extends linearly in the axial direction and is open toward both sides in the axial direction.

[0158] 13, the case 1006 includes an annular core metal 1007 and an outer circumferential seal portion 1008. The case 1006 has a function of holding the lip member 1004 and the backup ring 1005, and also has a function of attaching to the housing 1002 and providing a secondary seal.

[0159] The core 1007 is made of a metal material and is formed in a ring shape with a U-shaped cross section. The core 1007 has a cylindrical portion 1070 extending in the axial direction, an inward rear flange portion 1071 extending radially inward from the left axial end of the cylindrical portion 1070, and an inward front flange portion 1072 extending radially inward from the right axial end of the cylindrical portion 1070. The core 1007 may be made of resin, and the material may be changed as appropriate.

[0160] The cylindrical portion 1070 has a thick plate portion that extends to the left while maintaining approximately the same thickness, i.e., radial length, a tapered plate portion 1073 that extends to the left from the left end of the thick plate portion while shrinking in thickness, and a thin plate portion that extends to the left from the left end of the tapered plate portion 1073 with approximately the same thickness and is connected to the rear flange portion 1071.

[0161] 13, in case 1006A before assembly, the thin plate portion of tubular portion 1070A extends linearly further to the left than in the state in Fig. 1, and rear flange portion 1071 is not yet formed. When case 1006A is crimped, tubular portion 1070A is plastically deformed so that left end portion 1071A of tubular portion 1070A becomes approximately parallel to front flange portion 1072, and left end portion 1071A becomes rear flange portion 1071.

[0162] 11 , the outer circumferential seal portion 1008 is made of H-NBR, i.e., hydrogenated nitrile rubber, and is fixed to the inserted core 1007 by vulcanization adhesion, and is hermetically attached to the core 1007. The outer circumferential seal portion 1008 is continuous from the left end face of the rear flange portion 1071 to the outer circumferential surface of the tubular portion 1070, the right end face, inner circumferential surface, and left end face of the front flange portion 1072, and to the axial center of the inner circumferential surface of the tubular portion 1070.

[0163] In the outer circumferential seal portion 1008, a portion that extends radially, particularly covering the left end face of the front flange portion 1072, is referred to as a radially extending portion 1080. Furthermore, a portion of the radially extending portion 1080 that extends axially to the left generally perpendicular to the outer diameter end and covers the thick plate portion of the cylindrical portion 1070 is referred to as an axially extending portion 1081. Furthermore, a portion of the axially extending portion 1081 that extends slantedly from the left end thereof toward the outer diameter side and the axially left side and covers the tapered plate portion 1073 of the cylindrical portion 1070 is referred to as an inclined portion 1082.

[0164] The outer circumferential seal portion 1008 has an annular bulge 1084 that protrudes outward from a portion that covers the outer circumferential surface of the cylindrical portion 1070. The bulge 1084 seals the gap between the housing 1002 and the mandrel 1007 when the outer circumferential seal portion 1008 is fitted into the housing 1002 together with the mandrel 1007. In other words, the outer circumferential seal portion 1008 functions as a so-called secondary seal.

[0165] In this embodiment, the case 1006 is configured to be directly attached to the housing 1002, but this is not limiting and the case 1006 may be attached to the housing 1002 via another member.

[0166] 11 and 13, in the assembled sealing device 1001, the base portion 1040 of the lip component 1004 is disposed radially inward relative to the axially extending portion 1081 and the inclined portion 1082 of the outer circumferential seal portion 1008.

[0167] The end face of the base 1040 on the sealed fluid side is pressed against a radially extending portion 1080 of the outer circumferential seal portion 1008. In addition, a portion of the outer circumferential surface 1040a of the base 1040 on the right side from the axial center is pressed against an axially extending portion 1081 of the outer circumferential seal portion 1008. As a result, the gap between the base 1040 and the outer circumferential seal portion 1008 is sealed in the radial direction as well.

[0168] The lip component 1004 is a separate component from the outer circumferential seal portion 1008 and is not directly fixed to the core metal 1007 in a sealed state.

[0169] Meanwhile, a portion of the outer peripheral surface 1040a of the base 1040 that is to the left of the axial center is spaced apart radially inward from the inclined portion 1082. A gap G10 having a right-angled triangular cross section and an annular shape that widens toward the left in the axial direction is formed radially between the left portion of the outer peripheral surface 1040a and the inner peripheral surface of the inclined portion 1082. Hereinafter, the gap G10 may also be referred to as the "gap G10 on the lip component 1004 side."

[0170] The lip component 1004 side means that the lip component 1004 is mainly involved in the division and configuration, such as the gap G10.

[0171] Furthermore, gap G10 corresponds to the gap on the lip seal portion side of the present invention, since its compartmentation and configuration mainly involve at least one of core metal 1007 and outer circumferential seal portion 1008, and lip component 1004. Furthermore, gap G10 corresponds to the gap on the backup ring side of the present invention, since its compartmentation and configuration mainly involve at least one of core metal 1007 and outer circumferential seal portion 1008, and backup ring 1005.

[0172] The backup ring 1005 is disposed on the inner diameter side of the thin plate portion of the cylindrical portion 1070 of the core metal 1007 and on the side opposite to the sealed fluid side of the lip component 1004. The outer diameter of the backup ring 1005, i.e., the diameter up to the outer peripheral surface 1050c, is slightly smaller than the inner diameter of the thin plate portion of the case 1006. As a result, a gap G20 having a rectangular cross section and an annular shape extending in the axial direction is formed radially between the outer peripheral surface 1050c and the inner peripheral surface of the thin plate portion. Hereinafter, the gap G20 may also be referred to as the "gap G20 on the backup ring 1005 side."

[0173] The backup ring 1005 side means that the backup ring 1005 is mainly involved in the divisions and configurations, such as the gap G20, the groove 1053 on the side opposite to the sealed fluid, and the groove 1054 on the outer diameter side.

[0174] Furthermore, gap G20 is mainly defined by at least one of core metal 1007 and outer periphery seal portion 1008 and backup ring 1005, and therefore corresponds to the gap on the backup ring side of the present invention.

[0175] Next, the space S10 on the backup ring 1005 side in this embodiment will be described. The space S10 has each of the anti-sealed fluid side grooves 1053 and each of the outer diameter side grooves 1054. The outer diameter side groove 1054 in the backup ring 1005 communicates with the gap G10 on the lip component 1004 side in the axial direction. The outer diameter side groove 1054 also opens toward the gap G20 on the backup ring 1005 side and communicates with this gap G20. In other words, the gap G20 on the backup ring 1005 side communicates with the gap G10 on the lip component 1004 side through the outer diameter side groove 1054.

[0176] The counter-sealed fluid-side groove 1053 in the backup ring 1005 communicates with a gap G10 on the lip component 1004 side and a gap G20 on the backup ring 1005 side through an outer diameter-side groove 1054. The counter-sealed fluid-side groove 1053 extends radially inward beyond the inner diameter edge of a rear flange portion 1071 of the case 1006. The portion positioned radially inward beyond the rear flange portion 1071 is open toward the external space A and communicates with the external space A. In other words, the space S10 communicates with the external space A and the gaps G10 and G20.

[0177] 13 , lip component 1004 and backup ring 1005 are disposed on the inner diameter side of case 1006A before assembly, and left end portion 1071A of uncrimped tubular portion 1070A is crimped as shown by the thick arrow in FIG.

[0178] As the left end 1071A of the uncrimped cylindrical portion 1070A is crimped, the backup ring 1005 is pushed axially rightward as indicated by the outline arrow in Fig. 13. The right corner portion on the outer diameter side of the base portion 1050 of the backup ring 1005 bites into the inclined portion 1082 of the outer circumferential seal portion 1008 while elastically deforming the inclined portion 1082.

[0179] The resilient force of this elastically deformed inclined portion 1082 is a resultant force of a force acting toward the inner diameter side of the backup ring 1005 and a force acting toward the left side in the axial direction.

[0180] The force acting on the backup ring 1005 toward the inner diameter side guides the backup ring 1005 in its radial position so that its axis substantially coincides with the axis of the case 1006 .

[0181] Furthermore, the base 1050 of the backup ring 1005, which is formed in a flat plate shape, comes into surface contact with the rear flange portion 1071 of the case 1006, so that the force received from the rear flange portion 1071 is less likely to be uneven. As a result, the axis of the backup ring 1005 is less likely to tilt relative to the axis of the case 1006.

[0182] As a result, the gap G20 on the backup ring 1005 side can be stably formed.

[0183] Furthermore, the backup ring 1005, which is being pushed in as the rear flange portion 1071 is formed, pushes the base portion 1040 of the lip component 1004 to the right in the axial direction, i.e., toward the front flange portion 1072, with its base portion 1050 being pressed axially against the base portion 1040 of the lip component 1004. This pressing force causes the base portion 1040 of the lip component 1004 to be pressed axially against the radially extending portion 1080 of the outer circumferential seal portion 1008.

[0184] The backup ring 1005 is also pushed axially to the right with its inclined portion 1051 pressed against the inner diameter end of the base portion 1040 and the outer diameter end of the lip portion 1041 .

[0185] 13, the force acting from the inclined portion 1051 on the lip component 1004 acts toward the outer diameter side and the right side in the axial direction. In other words, the force acting from the inclined portion 1051 on the lip component 1004 is a resultant force of the force acting toward the right side in the axial direction and the force acting toward the outer diameter side.

[0186] The lip portion 1041 of the lip component 1004 is maintained in a state inclined toward the right and toward the inner diameter side by a force acting from the inclined portion 1051 on the lip component 1004 toward the right in the axial direction.

[0187] Due to the force acting from the inclined portion 1051 toward the outer diameter side on the lip component 1004, the portion of the outer peripheral surface 1040a of the lip component 1004 from the axial center to the right side is pressed toward the axially extending portion 1081 and the inclined portion 1082 of the outer peripheral seal portion 1008. As a result, the axially extending portion 1081 and the inclined portion 1082 are pressed toward the outer diameter side and elastically deformed, generating a resilient force.

[0188] The elastic force generated by the axially extending portion 1081 and the inclined portion 1082 acts toward the inner diameter side of the base portion 1040. This elastic force guides the lip component 1004 to a radial position such that its axis approximately coincides with the axis of the case 1006. This allows the gap G10 on the lip component 1004 side to be stably formed.

[0189] In addition, due to the combined force of the force acting from the inclined portion 1051 toward the outer diameter side of the lip component 1004 and the force acting from the base 1050 of the backup ring 1005 toward the right side in the axial direction of the lip component 1004, the corner formed by the end face of the base 1040 on the sealed fluid side and the outer peripheral surface 1040a of the base 1040 is pushed into the corner formed by the radial extension portion 1080 and the axial extension portion 1081 of the outer peripheral seal portion 1008.

[0190] This increases the holding force of the lip component 1004 by the case 1006 and the backup ring 1005. This makes it difficult for the lip component 1004 to slip out of the case 1006, even if the lip component 1004 is made of a rubber material that is more easily elastically deformed than PTFE, which is known as an elastic material.

[0191] As described above, in the sealing device 1001 of this embodiment, the peripheral seal portion 1008 and a portion of the lip component 1004 are in contact with the backup ring 1005, so that the intrusion of the sealed fluid through these gaps can be prevented. Furthermore, the space S10 ensures a large volume into which the sealed fluid that has infiltrated the peripheral seal portion 1008 or the lip component 1004 can flow. Therefore, even if the sealed fluid is a foamable carbon dioxide heat transfer medium that foams when it changes state from liquid to gas, the lip component 1004 can be prevented from slipping out or from being damaged by foaming. These features provide stable sealing performance.

[0192] Furthermore, the gap G10 on the lip component 1004 side faces the outer circumferential seal portion 1008 and a part of the lip component 1004. As a result, the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 is easily guided into the gap G10. In the sealing device 1001, the space S10 communicates with the gap G10, so the sealed fluid can be quickly guided into the space S10 through the gap G10.

[0193] Furthermore, the outer circumferential seal portion 1008 and a portion of the lip component 1004 face the gap G10 on the lip component 1004 side and the gap G20 on the backup ring 1005 side. As a result, the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 is easily guided into the gaps G10, G20. In the sealing device 1001, the space S10 communicates with the gaps G10, G20, so the sealed fluid can be quickly guided into the space S10 through the gaps G10, G20.

[0194] Furthermore, in the sealing device 1001, the space S10 communicates with the external space A, so that the sealed fluid that has flowed into the space S10 can escape to the external space A.

[0195] Furthermore, the space S10 has an anti-sealed fluid side groove 1053 formed in the backup ring 1005, so that the sealed fluid that has entered the outer peripheral seal portion 1008 or the lip component 1004 can be stably released to the external space A with a simple structure.

[0196] Furthermore, the anti-sealed fluid side groove 1053 is a groove that is open toward the anti-sealed fluid side, so that the sealed fluid can easily escape in the direction opposite to the lip component 1004 .

[0197] In addition, since the outer diameter side groove 1054 is a groove that opens toward the outer diameter side, it is easy to guide the sealed fluid that has entered the outer peripheral seal portion 1008 or the lip component 1004 into the outer diameter side groove 1054. Furthermore, since the outer diameter side groove 1054 is in communication with the anti-sealed fluid side groove 1053, it is easy to guide the sealed fluid that has flowed into the outer diameter side groove 1054 into the anti-sealed fluid side groove 1053. As a result, the sealed fluid can be more smoothly released into the external space A.

[0198] In this embodiment, a structure in which the anti-sealed fluid side groove 1053 and the outer diameter side groove 1054 are provided has been described, but the present invention is not limited to this, and only the anti-sealed fluid side groove 1053 may be provided. Even with this configuration, the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 can be released into the outer space A. However, from the viewpoint of ensuring an area facing the outer circumferential seal portion 1008 or the lip component 1004 and easily improving the efficiency of guiding the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 into the space, it is preferable to provide the anti-sealed fluid side groove 1053 and the outer diameter side groove 1054.

[0199] Furthermore, since a plurality of anti-sealed fluid grooves 1053 are provided in the circumferential direction, an area facing the outer circumferential seal portion 1008 and the lip component 1004 is secured, thereby increasing the efficiency of guiding the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 to the space S10, and the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 can be stably released into the outer space A. The same applies to the outer diameter grooves 1054 that are provided in the circumferential direction.

[0200] Although only one anti-sealed fluid side groove 1053 may be provided, it is preferable to provide a plurality of grooves from the viewpoint of ensuring an area facing the outer circumferential seal portion 1008 and the lip component 1004 and from the viewpoint of facilitating the release of the sealed fluid into the outer space A. The same applies to the outer diameter side grooves 1054 provided in plurality in the circumferential direction.

[0201] Furthermore, the gap G10 on the lip component 1004 side widens toward the left in the axial direction, making it easier to guide the sealed fluid into the outer diameter side groove 1054.

[0202] In addition, the gap G10 on the lip component 1004 side is annular, which facilitates dispersion of the sealed fluid into the plurality of outer diameter side grooves 1054. Furthermore, the sealed fluid that has flowed into a position other than the position where the outer diameter side groove 1054 is formed can be guided to one of the outer diameter side grooves 1054.

[0203] Although the gap G10 on the lip component 1004 side does not have to be formed, it is preferable that it be formed from the viewpoint of ensuring an area facing the outer seal portion 1008 and the lip component 1004, and from the viewpoint of making it easier for the sealed fluid to escape into the external space A.

[0204] Furthermore, the gap G20 on the backup ring 1005 side is annular, which facilitates dispersion of the sealed fluid into the plurality of anti-sealed fluid side grooves 1053. This allows the sealed fluid to escape to the external space A more stably.

[0205] Although the gap G20 on the backup ring 1005 side does not have to be formed, it is preferable that it be formed from the viewpoint of ensuring an area facing the outer seal portion 1008 and the lip component 1004, and from the viewpoint of making it easier for the sealed fluid to escape to the external space A.

[0206] Furthermore, in the sealing device 1001, the anti-sealed fluid side groove 1053 and the outer diameter side groove 1054 communicate with the gaps G10 and G20, so the volume of the area connected to the space S10 is larger than in a structure in which the gaps G10 and G20 are not formed. This makes it easier to tolerate changes in the state of the sealed fluid that has passed through the outer peripheral seal portion 1008 and the lip component 1004 while ensuring the area facing the outer peripheral seal portion 1008 and the lip component 1004.

[0207] In this embodiment, the anti-sealed fluid side groove 1053 and the outer diameter side groove 1054 are described as being directly connected to each other, but this is not limited thereto, and they may be connected to each other through the gap G20 on the backup ring 1005 side.

[0208] Furthermore, the outer seal portion 1008 and the lip component 1004 are made of hydrogenated nitrile rubber, and the sealed fluid is a carbon dioxide heat transfer medium, so that the outer seal portion 1008 and the lip component 1004 can be kept highly sealed while being prevented from being damaged.

[0209] Furthermore, since the outer circumferential seal portion 1008 and the lip component 1004 are made of rubber, the environmental impact can be reduced compared to a lip component made of PTFE.

[0210] In this embodiment, the space S10 is directly connected to the external space A, but the present invention is not limited to this and may be connected to a buffer space that is configured to be able to communicate with the external space A via a relief valve, or may be modified as appropriate. In other words, "connected to the outside" in the present invention means that the space S10 can be connected to the outside, and another space may be interposed between the outside and the space.

[0211] The sealing device 1001 includes a lip component 1004 arranged to be in sliding contact with a rotating shaft 1003 inserted through a housing 1002, a backup ring 1005 arranged on the side of the lip component 1004 opposite to the sealed fluid, and a case 1006 attached to the housing 1002 and holding the lip component 1004 and the backup ring 1005, and seals between the housing 1002 and the rotating shaft 1003, and a space S10 connected to a gap G10 between the case 1006 and an outer peripheral surface 1040a serving as the outer periphery of the lip component 1004 is provided on the backup ring 1005 side. As a result, a large volume into which the heat transfer medium can flow can be secured by the gap G10 on the lip component 1004 side and the space S10 on the backup ring 1005 side connected to this gap G10, and therefore movement of the lip component 1004 due to expansion of the heat transfer medium can be prevented.

[0212] Moreover, at least a part of the space S10 is provided in the backup ring 1005. This allows the sealing device 1001 to easily provide the space S10.

[0213] Furthermore, the space S10 is provided on the outer peripheral surface 1050c of the backup ring 1005 and includes an outer diameter groove 1054 extending in the axial direction, so that a portion of the space S10 is secured between the case 1006 and the outer peripheral surface 1050c of the backup ring 1005. This makes it easier to guide the heat transfer medium that has flowed into the gap G10 on the lip component 1004 side to the left in the axial direction, that is, in the direction away from the lip component 1004. This makes it difficult for the heat transfer medium to act in a direction that causes it to escape from the lip component 1004.

[0214] Furthermore, the space S10 is provided on the left end face 1050b, which is the end face on the side opposite to the sealed fluid of the backup ring 1005, and includes the radially extending opposite-to-sealed-fluid-side groove 1053, so that an area in the space S10 that is in communication with the external space A is secured with a simple configuration.

[0215] The space S10 also includes an outer diameter groove 1054 provided on the outer peripheral surface 1050c of the backup ring 1005, and an anti-sealed fluid groove 1053 provided on a left end face 1050b, which is the end face of the backup ring 1005 on the anti-sealed fluid side, and communicating with the outer diameter groove 1054. This allows the heat transfer medium that has flowed into the gap G10 on the lip component 1004 side to be guided to the left in the axial direction, that is, in the direction away from the lip component 1004, and to escape to the external space A. This makes it more difficult for the heat transfer medium to act on the lip component 1004 in the escape direction.

[0216] In addition, since multiple anti-sealed fluid side grooves 1053 and outer diameter side grooves 1054 are provided in the circumferential direction, the heat transfer medium that flows into the gap G10 on the lip component 1004 side can be stably released into the external space A.

[0217] In this embodiment, the anti-sealed fluid side groove 1053 and the outer diameter side groove 1054 are described as being directly connected to each other, but this is not limited thereto, and they may be connected to each other through the gap G20 on the backup ring 1005 side.

[0218] Furthermore, the gap G10 on the lip component 1004 side widens toward the left in the axial direction, so even if the heat transfer medium that flows into the gap G10 expands, it is easily guided to the space S10 on the backup ring 1005 side. This makes it more difficult for the lip component 1004 to slip out of the case 1006.

[0219] Furthermore, the case 1006 is shaped to have the tapered plate portion 1073 of the core metal 1007, which facilitates the formation of the inclined portion 1082 of the outer circumferential seal portion 1008. This makes it possible to stably ensure the gap G10 on the lip component 1004 side, which widens toward the side away from the sealed fluid.

[0220] Furthermore, the outer diameter of the base 1040 of the lip component 1004 is smaller than the outer diameter of the base 1050 of the backup ring 1005. This makes it possible to utilize the elastic force of the outer circumferential seal portion 1008 to achieve centering of both the lip component 1004 and the backup ring 1005.

[0221] The outer diameter of the backup ring may be the same as the outer diameter of the lip component, or may be smaller than the outer diameter of the lip component as in Example 9 (see FIG. 15 ) described later, or may be changed as appropriate. On the other hand, it is more preferable that the outer diameter of the backup ring is larger than the outer diameter of the lip component, as in this example, because the force transmitted from the rear flange portion 1071 to the lip component 1004 is more easily dispersed approximately evenly by the backup ring 1005 interposed therebetween.

[0222] The bottom surface of the groove 1053 at its inner diameter end is curved and protrudes toward the inner diameter side and toward the right in the axial direction, which makes it easier to guide the heat transfer medium to the axially opposite side of the lip component 1004, and therefore makes it difficult for the heat transfer medium released into the external space A to act on the end surface of the lip portion 1041 of the lip component 1004 on the opposite side to the sealed fluid.

[0223] Furthermore, the inner diameter of the rear flange portion 1071 of the case 1006 is larger than the inner diameter of the base portion 1050 of the backup ring 1005. As a result, the inner diameter end of the anti-sealed fluid side groove 1053 is located on the outer diameter side of the inclined portion 1051 of the backup ring 1005, and a structure can be easily configured in which the heat transfer medium escapes into the external space A in the axially opposite direction from the lip component 1004.

[0224] In addition, the front flange portion 1072 and the radially extending portion 1080 of the case 1006 protrude radially inward more than the rear flange portion 1071. Also, the inclined portion 1051 of the backup ring 1005 is located radially inward more than the front flange portion 1072. This ensures a radial region where the base portion 1040 of the lip component 1004 and the radially extending portion 1080 of the case 1006 are in surface contact, while maintaining a state in which the lip portion 1041 of the lip component 1004 is inclined toward the sealed fluid side and the radially inward side.

[0225] Furthermore, the left end surface 1050b of the base 1050 formed in a flat plate shape is brought into face contact with the right side surface of the rear flange portion 1071, which is an inelastic body. As a result, the backup ring 1005 is subjected to a substantially uniform force in the radial direction, and is thereby firmly fixed to the case 1006, and the anti-sealed fluid side groove 1053 and the outer diameter side groove 1054 can be secured with high dimensional accuracy.

[0226] Next, a sealing device according to an eighth embodiment will be described with reference to Fig. 14. Note that the same components as those shown in the first embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0227] Referring to FIG. 14, a sealing device 1101 has a backup ring 1105 formed with a plurality of outer diameter grooves 1154, but differs from the backup ring 1005 of the seventh embodiment in that no groove is formed on the opposite side to the sealed fluid.

[0228] The space S11 on the backup ring 1105 side is formed by the outer diameter side groove 1154. In other words, the space S11 of the backup ring 1105 is not in communication with the outer space A.

[0229] Even with this configuration, a large volume into which the heat transfer medium can flow can be secured by the gap G10 on the lip component 1004 side and the space S11 on the backup ring 1105 side, thereby preventing the lip component 1004 from moving due to the expansion of the heat transfer medium.

[0230] On the other hand, the sealing device 1001 of the seventh embodiment is preferable in that it is possible to release the expanded heat medium to the outside.

[0231] Next, a sealing device according to a ninth embodiment will be described with reference to Fig. 15. Note that the same components as those shown in the first embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0232] 15, in a sealing device 1201, the outer diameter of a backup ring 1205 is smaller than the outer diameter of a base portion 1040 of the lip component 1004. As a result, a gap G1220 on the backup ring 1205 side is directly connected to a gap G10 on the lip component 1004 side.

[0233] Furthermore, the backup ring 1205 is formed with a plurality of grooves 1253 adjacent to the sealed fluid. The space S12 in this embodiment is formed by the plurality of grooves 1253 adjacent to the sealed fluid.

[0234] Even with this configuration, the heat transfer medium that has flowed into the gap G10 on the lip component 1004 side can be released to the external space A through the space S12.

[0235] In addition, since the gap G1220 on the backup ring 1205 side is annular and can be connected to the gap G10 on the lip component 1004 side in the circumferential direction, the heat transfer medium that flows into the gap G10 on the lip component 1004 side can easily escape to the external space A.

[0236] On the other hand, in terms of the difficulty in aligning the backup ring 1205 with the case 1006, the backup ring 1005 of the seventh embodiment is preferable.

[0237] Next, a sealing device according to a tenth embodiment will be described with reference to Fig. 16. Note that the same components as those shown in the first embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0238] Referring to Figure 16, the sealing device 1301 includes a first lip component 1304, a first backup ring 1305, a core metal 1306, an O-ring 1307 as an outer peripheral seal portion, a second lip component 1308, and a second backup ring 1309.

[0239] The outer seal portion may be configured to seal the space between the core bar and the housing, as in the case of O-ring 1307 in this embodiment; in other words, it does not have to be attached integrally with the core bar, and the type of outer seal portion may be changed as appropriate.

[0240] Since sealing devices having multiple types of lip members and backup rings, such as sealing device 1301, are well known, only the first lip member 1304 and the first backup ring 1305, which are involved in preventing movement of the lip member, will be described.

[0241] The first lip component 1304 has a plurality of through grooves 1342 recessed from the outer peripheral surface of the base 1340 toward the inner diameter side and penetrating in the axial direction. A gap G1310 on the first lip component 1304 side is defined by these through grooves 1342 and the mandrel 1306. In this way, the gap on the lip seal portion side in the present invention may be formed by cutting out a portion of the lip seal portion, or may be changed as appropriate.

[0242] The first backup ring 1305 has a plurality of anti-sealed fluid grooves 1353 and a plurality of outer diameter grooves 1354. The anti-sealed fluid grooves 1353 penetrate the base portion 1350 and the inclined portion 1351 of the first backup ring 1305 in the radial direction.

[0243] The anti-sealed fluid groove 1353 is formed in a location that does not correspond to any of the contact locations between the backup ring and the outer circumferential seal portion, the contact location between the backup ring and the lip seal portion, and the contact location between the backup ring and the mandrel, and is therefore not included in the space of the present invention. In other words, the space S13 in this embodiment is formed by a plurality of outer diameter grooves 1354 and communicates with the external space A through a plurality of anti-sealed fluid grooves 1353. In this way, the space may be connected to the outside via another flow path such as the anti-sealed fluid groove 1353, as long as it is connected to the outside.

[0244] Even with this configuration, the heat transfer medium that has flowed into the gap G1310 on the first lip component 1304 side can be released to the external space A through the space S13 and the anti-sealed fluid-side groove 1353. In addition, since the anti-sealed fluid-side groove 1353 penetrates the base 1350 of the first backup ring 1305 in the radial direction, the sealed fluid can be quickly released to the external space A.

[0245] On the other hand, in order to facilitate guiding the heat transfer medium in the axial direction away from the lip member and escaping to the outside, it is preferable that the anti-sealed fluid side groove be open in the axial direction away from the lip member and that the inner diameter side be closed, as in the seventh embodiment.

[0246] Furthermore, since it is difficult to align the through groove 1342 in the first lip component 1304 with the outer diameter side groove 1354 in the first backup ring 1305, and there is a risk of unintended gaps occurring other than the through groove 1342 in the first lip component 1304, a gap that is continuous in the circumferential direction, such as the gap G10 on the lip component 1004 side in Example 7, is preferable.

[0247] Although alignment with the core bar 1306 becomes more complicated, the outer diameter of the base of the first lip component may be smaller than the inner diameter of the core bar 1306, and a continuous gap may be formed radially between the inner surface of the core bar 1306 and the outer surface of the base.

[0248] As described above, regardless of the number or type of lip components or backup rings, by providing a space on the backup ring side that leads to a gap between the outer periphery of at least one lip component that is located on the side opposite the sealed fluid from the case, movement of the lip component due to expansion of the heat transfer medium can be prevented.

[0249] Next, a sealing device according to an eleventh embodiment will be described with reference to Fig. 17. Note that the same components as those shown in the first embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0250] 17, sealing device 1401 has a thin, annular rubber membrane 1409 fixed to a rear flange 1471 of a case 1406. The material of membrane 1409 may be changed as appropriate.

[0251] The membrane material 1409 is fixed in a state in which its outer diameter end is cantilevered on the inner diameter end of the rear flange portion 1471. The membrane material 1409 also protrudes toward the inner diameter side beyond the rear flange portion 1471, straddling the anti-sealed fluid side groove 1053 of the backup ring 1005 and abutting against the left end face 1050b of the base portion 1050 of the backup ring 1005. In other words, the membrane material 1409 closes the opening on the inner diameter side of the anti-sealed fluid side groove 1053. This makes it difficult for dust and the like floating in the external space A to flow into the space S10.

[0252] Furthermore, when the heat transfer medium that has flowed into the gap G10 on the lip component 1004 side expands and the pressure in the space S10 exceeds a certain level, the membrane material 1409 elastically deforms in the direction away from the left end face 1050b of the backup ring 1005, and the anti-sealed fluid-side groove 1053 communicates with the external space A. This allows the heat transfer medium to escape to the external space A.

[0253] Next, a sealing device according to a twelfth embodiment will be described with reference to Fig. 18. Note that the same components as those shown in the first embodiment will be assigned the same reference numerals and redundant description will be omitted.

[0254] 18 , in the sealing device 1501, a through hole 1554 is formed that passes through the outer diameter side of a base 1550 of a backup ring 1505 in the axial direction. Also, an anti-sealed fluid side groove 1553 in the backup ring 1505 communicates with the through hole 1554. The space S15 in this embodiment is formed by the multiple anti-sealed fluid side grooves 1553 and the multiple through holes 1554.

[0255] Even with this configuration, the space S15 can be easily provided.

[0256] In this embodiment, it has been described that the gap G10 on the lip component 1004 side and the external space A are in communication with each other via the through hole 1554 and the anti-sealed fluid side groove 1553, but this is not limiting, and there may be one through hole extending at an angle from the gap G10 on the lip component 1004 side toward the external space A. In other words, the formation direction and number of through holes may be changed as appropriate.

[0257] Furthermore, in this embodiment, the configuration in which the through hole 1554 is formed as an alternative to the outer diameter side groove 1054 of the seventh embodiment has been described, but the present invention is not limited to this, and a radial through hole penetrating in the radial direction may be formed as an alternative to the anti-sealed fluid side groove 1053 of the seventh embodiment. The radial through hole may communicate with the outer diameter side groove 1054 or may communicate with the through hole 1554, or may communicate with the gap G1220 on the backup ring 1205 side of the ninth embodiment if a separate space is provided, and may be changed as appropriate as long as it can communicate with the gap G10 on the lip component 1004 side.

[0258] Also, the gap G20 on the backup ring 1505 side is not in communication with the space S15. For this reason, the outer diameter side groove 1054 of the seventh embodiment is preferable as it can ensure a larger volume into which the heat transfer medium can flow.

[0259] A sealing device according to a thirteenth embodiment will be described with reference to Figures 19 and 20. Note that the same components as those shown in the first embodiment will be given the same reference numerals and redundant description will be omitted.

[0260] 19 and 20 , the sealing device 2001 has eight sealed fluid-side grooves 2053 formed as radially penetrating portions in the backup ring 2005. The eight sealed fluid-side grooves 2053 are provided at contact portions between the backup ring 2005 and the outer circumferential seal portion 1008 and the lip component 1004. These sealed fluid-side grooves 2053 are evenly spaced. Note that in FIG. 20 , the sealed fluid-side grooves 2053 are shown with a dotted pattern for clarity.

[0261] The sealed fluid-side groove 2053 is recessed axially leftward from a right end face 2050a of the base portion 2050, a right end face 2051a of the inclined portion 2051, and a right end face 2052a of the inner diameter end portion 2052, and is open axially rightward, in other words, toward the lip component 1004. The sealed fluid-side groove 2053 also penetrates the backup ring 2005 in the radial direction, and is open radially toward both sides.

[0262] Here, the right end face 2050a of the base portion 2050 is disposed closer to the sealed fluid than the left end face 2050b of the base portion 2050, in other words, closer to the lip component 1004. The right end face 2051a of the inclined portion 2051 extends from the inner diameter end of the right end face 2050a of the base portion 2050, inclining toward the inner diameter side and rightward. The right end face 2052a of the inner diameter end portion 2052 extends from the inner diameter end of the right end face 2051a of the inclined portion 2051 toward the inner diameter side. These right end faces 2050a, 2051a, 2052a are end faces on the lip component side in the present invention.

[0263] 19 , the sealed fluid-side groove 2053 has a bottom surface that extends linearly in the radial direction. As a result, the depth of the portion of the sealed fluid-side groove 2053 formed in the base portion 2050, i.e., the length in the left-right direction, is substantially constant along the radial direction. The depth of the portion of the sealed fluid-side groove 2053 formed in the inclined portion 2051 becomes deeper toward the inner diameter side. The depth of the portion of the inner diameter end portion 2052 is substantially constant along the radial direction and is deeper than the portions of the base portion 2050 and the inclined portion 2051.

[0264] The sealed fluid groove 2053 is open toward the lip component 1004 and communicates with the gap G10 on the lip component 1004 side in the axial direction. More specifically, the sealed fluid groove 2053 extends continuously from the point where it communicates with the gap G10 toward both the outer diameter side and the inner diameter side. This makes it easier to maintain communication between the sealed fluid groove 2053 and the gap G10. Furthermore, as described above, the gap G10 widens toward the left side, making it easier to maintain communication between the sealed fluid groove 2053 and the gap G10.

[0265] The sealed fluid-side groove 2053 is open toward and communicates with the gap G20 on the backup ring 2005 side. In other words, the gap G20 on the backup ring 2005 side communicates with the gap G10 on the lip component 1004 side through the sealed fluid-side groove 2053.

[0266] The sealed fluid-side groove 2053 has an end on its inner diameter side that is open toward the inner diameter side, in other words, toward the external space A. As a result, the sealed fluid-side groove 2053 communicates with the external space A.

[0267] Furthermore, the inclined portion 2051 of the backup ring 2005 abuts against the inner diameter end of the base 1040 of the lip component 1004 and the outer diameter end of the lip portion 1041, thereby holding the lip portion 1041 in a state inclined toward the right and toward the inner diameter side. As described above, the inclined portion 2051 and the inner diameter end portion 2052 of the sealed fluid side groove 2053 are deeper than the base 2050. This makes it difficult for the inner diameter end of the sealed fluid side groove 2053 to be blocked by the lip component 1004, and makes it easier to maintain a state in which it communicates with the external space A.

[0268] In this embodiment, the space S20 on the side of the backup ring 2005 is formed by eight sealed fluid side grooves 2053 and communicates with the outer space A.

[0269] In the sealing device 2001 of this embodiment, the outer circumferential seal portion 1008 and the lip component 1004 are in contact with the backup ring 2005, so that the infiltration of the sealed fluid through any gaps therebetween can be prevented. In addition, the space S20 ensures a large volume into which the sealed fluid that has infiltrated the outer circumferential seal portion 1008 or the lip component 1004 can flow. Therefore, even if the sealed fluid is a foamable carbon dioxide heat transfer medium that foams when it changes state from liquid to gas, it is possible to prevent the lip component 1004 from slipping out or damage to the outer circumferential seal portion 1008 or the lip component 1004 due to foaming of the sealed fluid.

[0270] Furthermore, the sealing device 2001 can allow the sealed fluid that has entered the outer circumferential seal portion 1008 or the lip component 1004 to escape to the outer space A through the space S20.

[0271] Furthermore, since the sealed fluid side groove 2053 is a groove that is open toward the sealed fluid side, that is, toward the lip component 1004 in the axial direction, it can guide the sealed fluid that has entered the outer seal portion 1008 or the lip component 1004 and quickly release it into the external space A.

[0272] Furthermore, in the sealing device 2001, the backup ring 2005 is provided with a space S20 on the backup ring 2005 side that communicates with the gap G10 on the lip component 1004 side. As a result, a large volume into which the heat medium can flow can be ensured by the gap G10 on the lip component 1004 side and the space S20 on the backup ring 2005 side that is connected to this gap G10, and therefore movement of the lip component 1004 due to expansion of the heat medium can be prevented.

[0273] The space S20 also includes a sealed fluid-side groove 2053 in the backup ring 2005, which faces the lip component 1004 of the backup ring 2005 and extends in the radial direction. This allows the sealed fluid-side groove 2053 to be disposed close to the gap G10 on the lip component 1004 side, making it possible to quickly release the heat transfer medium that has flowed into the gap G10 into the external space A.

[0274] Furthermore, since the inner diameter side of the sealed fluid side groove 2053 in the backup ring 2005 is open toward the external space A, even if the lip component 1004 moves toward the backup ring 2005, the heat transfer medium can be reliably released from the sealed fluid side groove 2053 into the external space A.

[0275] Furthermore, since a plurality of sealed fluid-side grooves 2053 are provided in the circumferential direction, the heat transfer medium that has flowed into the gap G10 on the lip component 1004 side can be stably released into the external space A.

[0276] Furthermore, the sealing device 2001 is provided with a gap G20 on the backup ring 2005 side that communicates with the sealed fluid groove 2053, so that even if the heat transfer medium flows into one sealed fluid groove 2053 in a concentrated manner, the heat transfer medium can be easily dispersed through the gap G20 to the plurality of sealed fluid grooves 2053. This allows the heat transfer medium to escape to the external space A more stably.

[0277] Furthermore, as in the seventh embodiment, the backup ring 2005 and the case 1006 can be easily aligned, and therefore the sealed fluid groove 2053 can be stably positioned in a direction approximately perpendicular to the axis of the rotating shaft 1003 while being spaced apart from the rotating shaft 1003 by approximately the same radial length around the circumferential direction.

[0278] Furthermore, the gap G10 on the lip component 1004 side widens toward the left in the axial direction, so that even if the heat transfer medium that has flowed into the gap G10 expands, it is easily guided to the sealed fluid-side groove 2053 in the backup ring 2005. This makes it more difficult for the lip component 1004 to slip out of the case 1006.

[0279] Furthermore, the left end surface 2050b of the base 2050 formed in a flat plate shape is brought into face contact with the right side surface of the rear flange portion 1071, which is an inelastic body. As a result, the backup ring 2005 is subjected to a substantially uniform force in the radial direction, and is thereby not only firmly fixed to the case 1006 but also ensures that the sealed fluid groove 2053 has high dimensional accuracy.

[0280] Furthermore, a portion of the lip component 1004 elastically returns toward the sealed fluid side groove 2053, thereby engaging with the backup ring 2005. This prevents the lip component 1004 from rotating.

[0281] Next, a sealing device according to a fourteenth embodiment will be described with reference to Fig. 21. Note that the same components as those shown in the first embodiment will be given the same reference numerals and redundant description will be omitted.

[0282] 21 , a sealing device 2101 has a backup ring 2105 formed with a plurality of sealed fluid-side grooves 2153. The sealed fluid-side grooves 2153 are formed in a base portion 2150 of the backup ring 2105, and their inner diameter ends are closed on the outer diameter side of the inclined portion 2151. The space S21 in this embodiment is defined by the plurality of sealed fluid-side grooves 2153.

[0283] As a result, the sealed fluid side gutter 2153 is not in communication with the external space A due to the lip component 1004 being pressed against the inclined portion 2151. This makes it difficult for dust and the like floating in the external space A to flow into the sealed fluid side gutter 2153.

[0284] Furthermore, when the heat transfer medium that has flowed into the gap G10 on the lip component 1004 side expands and the pressure in the sealed fluid-side groove 2153 exceeds a certain level, the lip component 1004 elastically deforms in the direction away from the inclined portion 2151, and the sealed fluid-side groove 2153 communicates with the external space A. This allows the heat transfer medium to escape to the external space A.

[0285] On the other hand, the sealing device 2001 of the thirteenth embodiment is preferable in that it is possible to stably release the expanded heat transfer medium to the outside.

[0286] Next, a sealing device according to a fifteenth embodiment will be described with reference to Fig. 22. Note that the same components as those shown in the first embodiment will be given the same reference numerals and redundant description will be omitted.

[0287] 22, a sealing device 2201 includes a first lip component 2204, a first backup ring 2205, a core metal 2206, a seal member 2207 as an outer circumferential seal portion, a second lip component 2208, and a second backup ring 2209. Hereinafter, the first lip component 2204 and the first backup ring 2205, which are involved in preventing movement of the lip component, will be described.

[0288] A plurality of through grooves 2242 are formed in the first lip component 2204. The through grooves 2242 and the core metal 2206 define a gap G2210 on the first lip component 2204 side.

[0289] The first backup ring 2205 has a plurality of sealed fluid grooves 2253 as radially penetrating portions. The sealed fluid grooves 2253 have a substantially uniform depth along the radial direction. In this embodiment, the space S22 is defined by the plurality of sealed fluid grooves 2253.

[0290] Even with this configuration, the heat transfer medium that has flowed into the gap G2210 on the first lip component 2204 side can be released to the external space A through the sealed fluid side groove 2253.

[0291] On the other hand, a groove having a deep portion that can come into contact with the lip portion, as in Example 13, is preferable in that the groove is less likely to be blocked by the lip member.

[0292] As in the fourteenth embodiment, the inner diameter end of the groove may be closed by a lip member.

[0293] Next, a sealing device according to a sixteenth embodiment will be described with reference to Fig. 23. Note that the same components as those shown in the first embodiment will be given the same reference numerals and redundant description will be omitted.

[0294] 23, a sealing device 2301 has a plurality of through grooves 2342 formed in a lip component 2304. The through grooves 2342 and the case 2306 define a gap G2310 on the lip component 2304 side.

[0295] The backup ring 2305 has a cylindrical portion 2355 extending axially leftward from the outer diameter end of the base portion 2350. A gap G2320 on the backup ring 2305 side formed radially between the backup ring 2305 and the case 2306 is longer in the axial direction and has a larger volume than the gap G20 in Example 7. The space S23 in this example is defined by a plurality of sealed fluid-side grooves 2353 formed in the backup ring 2305.

[0296] The lip component 2304 and the backup ring 2305 are held by the case 2306 with the cylindrical portion 2355 pressed against the rear flange portion 2371 of the case 2306 .

[0297] Even with this configuration, the heat transfer medium that has flowed into the gap G2310 on the lip component 2304 side can be released to the external space A through the sealed fluid side groove 2353.

[0298] Furthermore, since a gap G2320 having a larger volume can be provided on the side of the backup ring 2305, movement of the lip component 2304 due to expansion of the heat transfer medium can be prevented.

[0299] On the other hand, the force that the rear flange portion 2371 applies to press the backup ring 2305 toward the lip component 2304 tends to be concentrated at the outer diameter end of the base portion 2350 of the backup ring 2305, and therefore the backup ring 2005 of Example 7 is preferable in that it makes it easier to firmly fix the lip component to the case.

[0300] Next, a sealing device according to a seventeenth embodiment will be described with reference to Fig. 24. Note that the same components as those shown in the first embodiment will be given the same reference numerals and redundant description will be omitted.

[0301] 24, eight anti-sealed fluid grooves 1053, eight outer diameter grooves 1054, and eight sealed fluid grooves 2053 are formed in the backup ring 2405. The anti-sealed fluid grooves 1053 and the sealed fluid grooves 2053 are formed so as to alternate in the circumferential direction.

[0302] With this configuration, the volume of the space on the backup ring 2405 side can be made larger than the volume of the space S10 on the backup ring 1005 side in Example 7, thereby preventing movement of the lip component 1004 due to expansion of the heat transfer medium.

[0303] Furthermore, since the volume of the space on the backup ring 2405 side can be made larger than the space S10 in the seventh embodiment, the heat transfer medium that flows into the gap G10 on the lip component 1004 side can be more efficiently released into the external space A.

[0304] Furthermore, since the anti-sealed fluid side groove 1053 and the sealed fluid side groove 2053 are formed so as to alternate in the circumferential direction, it is possible to prevent the formation of each groove from affecting the other, while ensuring a sufficient depth for each groove, and it is easy to guide the fluid evenly from the circumferential direction into the anti-sealed fluid side groove 1053 and the sealed fluid side groove 2053.

[0305] The anti-sealed fluid groove and the sealed fluid groove may be formed at the same circumferential position, or their positions may be changed as appropriate. The sealed fluid groove may also be connected to the outer diameter groove. The number of anti-sealed fluid grooves and the number of sealed fluid grooves may be different.

[0306] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0307] For example, in the above-described first to sixth embodiments, the sealing device has been described as sealing the space on the opposite side to the sealed fluid side and the space on the sealed fluid side, and maintaining a pressure difference between the space on the opposite side to the sealed fluid side and the space on the sealed fluid side. However, this is not limited to this, and the sealing device may only seal the space on the opposite side to the sealed fluid side and the space on the sealed fluid side.

[0308] In addition, in the above-described Examples 1 to 6, the space opposite the sealed fluid side and the space on the sealed fluid side were described as being internal spaces into which a heat transfer medium or oil flows, but this is not limiting, and for example, as in the above-described Examples 7 to 17, the space opposite the sealed fluid side may be an external space that communicates directly or indirectly with the atmosphere, or only the space on the sealed fluid side may be an internal space into which the sealed fluid flows. In other words, the fluids flowing into the space opposite the sealed fluid side of the sealing device and the space on the sealed fluid side may be different.

[0309] In this configuration, the outside of the present invention is the external space, that is, the space on the side opposite to the sealed fluid.

[0310] In addition, in the seventh to seventeenth embodiments, the space opposite the sealed fluid side is an outer space that communicates directly or indirectly with the atmosphere, and only the space on the sealed fluid side is an inner space into which the sealed fluid flows, but this is not limiting, and for example, as in the first to sixth embodiments, the space opposite the sealed fluid side and the space on the sealed fluid side may be inner spaces into which a heat transfer medium or oil flows. In other words, the fluid flowing into the space opposite the sealed fluid side from the sealing device and the space on the sealed fluid side may be the same.

[0311] With this configuration, the outside of the present invention is a low-pressure space, that is, the outside of the present invention is the space on the side opposite to the sealed fluid.

[0312] Furthermore, in the first to seventeenth embodiments, a compressor is used as an example of the fluid equipment, but the invention is not limited to this and may be a pump or may be modified as appropriate.

[0313] Furthermore, in the first to seventeenth embodiments, the heat transfer medium is used as an example of the sealed fluid, but the sealed fluid is not limited to this and may be a gas or liquid other than the heat transfer medium, and may be changed as appropriate.

[0314] Furthermore, in Examples 1 to 17, carbon dioxide heat transfer medium (R744) was used as an example of the heat transfer medium, but this is not limited thereto, and other natural heat transfer mediums such as propane (R290), isobutane (R600a), and ammonia (R717) may also be used, or so-called fluorocarbon-based heat transfer mediums such as hydrofluorocarbons may also be used, and may be changed as appropriate.

[0315] In addition, in Examples 1 to 17, the outer seal portion and the lip seal portion are made of H-NBR, i.e., hydrogenated nitrile rubber, but they may be made of other rubbers. Synthetic rubbers, such as NBR, i.e., nitrile rubber, are preferable. Furthermore, the outer seal portion and the lip seal portion may be made of different materials.

[0316] In addition, in Examples 1 to 17, the grooves and through-holes that define the space are provided in the backup ring, but this is not limiting, and they may be provided in the mandrel, the outer circumferential seal portion, or the lip seal portion. On the other hand, it is preferable to provide the grooves and through-holes in the backup ring, since the type and shape of the backup ring are more easily changed depending on the fluid equipment to which it is applied than the mandrel.

[0317] Furthermore, in Examples 1 to 17, a structure in which a portion of the outer peripheral seal portion is interposed between the backup ring and the core bar has been described, but this is not limited to this, and a portion of the lip seal portion may be interposed between the backup ring and the core bar, or, for example, a portion of the outer peripheral seal portion and a portion of the lip seal portion may be interposed alternately in the circumferential direction, and this may be modified as appropriate.

[0318] In addition, in the first embodiment and the like, the radial through-portions are arranged at equal intervals in the circumferential direction, but the present invention is not limited to this and the arrangement may be changed as appropriate. The same applies to the axial through-portions.

[0319] Furthermore, in the above-described first to sixth embodiments, the seal member has been described as having a structure in which the outer circumferential seal portion and the lip seal portion are integrally molded, but this is not limited thereto and the seal member may be separate as long as they are attached to the mandrel in a sealed manner. However, because fluid pressure acts separately on the outer circumferential seal portion and the lip seal portion, which are separate, there is a risk that they may peel off from the mandrel or unintended elastic deformation may occur, resulting in a deterioration in sealing performance. From the perspective of more stable sealing performance, a structure in which the outer circumferential seal portion and the lip seal portion are integrally molded as in this embodiment is preferable.

[0320] Furthermore, in the above-described Examples 1 to 6, the sealing member has an outer circumferential seal portion and a lip seal portion that are integrally formed from rubber material of the same composition, but this is not limited to this, and the outer circumferential seal portion 3007 and the lip seal portion 3008 may have different compositions due to the addition of an additive, for example, as in the modified sealing member 3005 shown in FIG.

[0321] Such a configuration can improve wear resistance, low friction, heat resistance, and the like when the lip seal portion 3008 is in sliding contact with the rotating shaft 3. Note that the portion with a different composition is not limited to the entire lip seal portion, and may be only a portion that is expected to be in sliding contact with the rotating shaft 3, such as the lip portion 3081, for example.

[0322] Furthermore, in the above-described Examples 1 to 6, a structure in which the protrusion is formed only on the outer peripheral seal portion has been described, but this is not limited to this, and a protrusion may be provided on the lip seal portion as long as the portion sandwiched axially between the mandrel and the backup ring is part of the lip seal portion.

[0323] In addition, in the above-described Examples 7 to 17, a structure in which at least one of the anti-sealing fluid side groove, the outer diameter side groove, and the sealing fluid side groove is provided in plural is exemplified, but the present invention is not limited to this, and any one of the grooves may be provided at least once, and may be modified as appropriate. On the other hand, it is preferable to provide a plurality of grooves so that the heat transfer medium that has flowed into the gap between the case and the lip component can be stably released to the outside.

[0324] In addition, in the above-described Examples 7 to 17, the structure in which at least one of the anti-sealing fluid groove, the outer diameter groove, and the sealing fluid groove is evenly arranged in the circumferential direction has been exemplified, but the arrangement may be changed as appropriate. For example, the plurality of sealing fluid grooves may be biased to one side in the circumferential direction.

[0325] REFERENCE SIGNS LIST 1 Sealing device 2 Housing 3 Rotating shaft 4 Mandrel 6 Backup ring 7 Outer circumferential seal portion 8 Lip seal portion 63 Radial through-portion 64 Axial through-portion F1 Low-pressure internal space (outside) F2 High-pressure internal space G1, G2 Gap (gap on backup ring side) S1 Space G10 Gap (gap on lip seal portion side)

Claims

1. A sealing device comprising a mandrel, an outer circumferential seal portion into which the mandrel is inserted and which seals the gap between the housing and the mandrel, a lip seal portion which seals the gap between the rotating shaft and the mandrel, and a backup ring which backs up the lip seal portion, wherein a space is provided in at least one of the contact points between the backup ring and the outer circumferential seal portion, the contact points between the backup ring and the lip seal portion, and the contact points between the backup ring and the mandrel.

2. A sealing device according to claim 1, wherein the space is in communication with a gap on the backup ring side between the backup ring and at least one of the mandrel and the outer peripheral seal portion.

3. A sealing device according to claim 1, wherein the space is in communication with a gap on the lip seal portion side between the lip seal portion and at least one of the mandrel and the outer circumferential seal portion.

4. A sealing device according to claim 1, wherein said peripheral seal portion and said lip seal portion are hermetically attached to said mandrel.

5. The sealing device according to claim 4, wherein the outer circumferential seal portion and the lip seal portion are integrally molded.

6. A sealing device according to claim 1, wherein the space is connected to the outside.

7. A sealing device according to claim 6, wherein the space has a radially penetrating portion that penetrates the backup ring in the radial direction.

8. A sealing device according to claim 7, wherein the radially penetrating portion is a groove that opens toward the side opposite to the sealed fluid.

9. A sealing device as described in claim 7, wherein the space has an axial through-portion that penetrates the backup ring in the axial direction and communicates with the radial through-portion, and the axial through-portion is a groove that opens toward the outer diameter side.

10. A sealing device according to claim 7, wherein the radially penetrating portion is a groove that opens toward the sealed fluid side.

11. A sealing device according to any one of claims 7 to 10, wherein a plurality of the radially penetrating portions are provided in the circumferential direction.

Images