Sealing device

Abstract

Provided is a seal device capable of inhibiting damage to a resin seal by a leaf spring. The seal device is characterized by including: a metal ring (110); a resin seal (120) that is in close contact with an outer peripheral surface of a shaft (200) in a state in which an inner peripheral side is deformed in a manner that curves toward a seal target region side; and a leaf spring (130) that presses the inner peripheral side of the resin seal (120) toward a radially inner side, and has a bent portion (133) that is formed by pre-bending a portion of a front end portion of the inner peripheral side of the leaf spring (130) so that, in a state in which the shaft (200) is inserted, the front end of the inner peripheral side of the leaf spring (130) is separated from the outer peripheral surface of the resin seal (120).

Description

TECHNICAL FIELD

[0001] The present application relates to a seal device having a resin seal. BACKGROUND

[0002] The present applicant has proposed a seal device having a resin seal, in which stable sealing performance can be maintained even if shaft eccentricity occurs (see Patent Literature 1). Reference is made to Figure 11 A seal device related to the prior art will be described. Figure 11 is a schematic cross-sectional view of a seal device related to the prior art.

[0003] The seal device 500 related to the prior art is provided with a metal ring 510 that is fitted to an inner peripheral surface of a shaft hole provided in a housing (not shown), a resin seal 520 that is composed of a plate-shaped and ring-shaped resin member, a plate spring 530 that is composed of a plate-shaped and ring-shaped metal member, and a fixing ring 540 that is used to fix the resin seal 520 and the plate spring 530 to the metal ring 510. The outer peripheral side of the resin seal 520 is fixed to the metal ring 510, and the inner peripheral side is in a state of being deformed so as to bend toward the side of a sealed object region, and is in close contact with the outer peripheral surface of a shaft 200 so as to be able to slide freely, as the shaft 200 is inserted. In addition, the outer peripheral side of the plate spring 530 is fixed to the metal ring 510, and the inner peripheral side is deformed so as to bend along the resin seal 520, and presses the inner peripheral side of the resin seal 520 toward the radially inner side, as the shaft 200 is inserted.

[0004] According to the seal device 500 configured as described above, even if shaft eccentricity occurs, the resin seal 520 is pressed toward the radially inner side by the plate spring 530, and thus it is possible to suppress departure from the outer peripheral surface of the shaft 200. Therefore, it is possible to maintain stable sealing performance.

[0005] However, it is known that in the seal device 500, the leading end of the plate spring 530 sometimes sinks into the resin seal 520 during deformation of the resin seal 520 and the plate spring 530 as the shaft 200 is inserted. That is, as Figure 12 indicated, the portion of the leading end of the plate spring 530 on the side of the resin seal 520 sometimes sinks into the resin seal 520 (see the S portion in the drawing). In addition, Figure 12 is a schematic cross-sectional view showing a portion of the resin seal 520 and the plate spring 530 during insertion of the shaft.

[0006] If such a phenomenon occurs, it is possible that the original function of the seal device 500 cannot be sufficiently exerted, and there is room for improvement.

[0007] PRIOR ART DOCUMENTS

[0008] PATENT LITERATURE

[0009] Patent Literature 1: Japanese Patent Application Publication No. 2015-203491 SUMMARY

[0010] An object of the present application is to provide a sealing device capable of inhibiting damage of a resin-made seal member by a leaf spring.

[0011] To solve the above problem, the present application employs the following means.

[0012] That is, the sealing device of the present application is a sealing device that seals an annular gap between a shaft and a housing that relatively move, characterized by comprising:

[0013] a metal ring that fits with an inner peripheral surface of a shaft hole provided in the housing;

[0014] a resin-made seal member that is composed of a plate-shaped and annular resin member, is fixed to the metal ring at an outer peripheral side, and is in a state of being deformable in a manner of bending toward a seal target region side at an inner peripheral side, and is in close contact with an outer peripheral surface of the shaft at the inner peripheral side in a freely slidable manner as the shaft is inserted;

[0015] a leaf spring that is composed of a plate-shaped and annular metal member, is fixed to the metal ring at an outer peripheral side, is deformed in a manner of bending along the resin-made seal member at an inner peripheral side as the shaft is inserted, and presses the inner peripheral side of the resin-made seal member toward a radially inner side, and

[0016] a front end of the leaf spring forms a sinkage-inhibiting structure toward the resin-made seal member.

[0017] According to the present application, the front end of the inner peripheral side of the leaf spring can be inhibited from sinking into the resin-made seal member at the time of insertion of the shaft and the like.

[0018] Further, a part of the front end portion of the inner peripheral side of the leaf spring is preferably composed of the sinkage-inhibiting structure by a bent portion that is bent in advance, so that the front end of the inner peripheral side of the leaf spring is separated from the outer peripheral surface of the resin-made seal member in a state where the shaft is inserted.

[0019] If such a structure is employed, by having the bent portion, the front end of the inner peripheral side of the leaf spring is composed to be separated from the outer peripheral surface of the resin-made seal member, so that the front end of the inner peripheral side of the leaf spring can be inhibited from sinking into the resin-made seal member at the time of insertion of the shaft and the like.

[0020] In a state before the shaft is inserted, a bending angle θ of the resin-made seal member side in the bent portion is preferably 30° or more.

[0021] By this, the front end of the inner peripheral side of the leaf spring can be more reliably inhibited from sinking into the resin-made seal member.

[0022] The radius of curvature R of the bending portion on the side of the resin seal in the bent portion of the bent portion is preferably 0.1 mm or more in a state before the shaft is inserted.

[0023] Thus, the bending portion of the bent portion can be prevented from sinking into the resin seal.

[0024] In a state before the shaft is inserted, when a radial width of the resin seal is set as L and a radial distance between a front end of the inner peripheral side of the leaf spring and a front end of the inner peripheral side of the resin seal is set as X, it is preferable that 0 < X ÷ L < 0.2 is satisfied.

[0025] In addition, in a state before the shaft is inserted, when a radial width of the resin seal is set as L and a radial distance from the front end of the inner peripheral side of the resin seal to the bent portion of the bending portion is set as Y, it is preferable that 0.03 < Y ÷ L < 0.3 is satisfied.

[0026] In addition, it is preferable that the sinking prevention structure is constituted by a bent portion that is bent in a manner that the front end of the leaf spring is folded back. Furthermore, it is preferable that the sinking prevention structure is constituted by providing a protection portion for covering the front end of the leaf spring at the front end of the leaf spring.

[0027] Furthermore, the above-described structures can be combined as much as possible.

[0028] As described above, according to the present application, the resin seal can be prevented from being damaged by the leaf spring. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a plan view of a sealing device to which Embodiment 1 of the present application relates;

[0030] Figure 2 is a bottom view of the sealing device to which Embodiment 1 of the present application relates;

[0031] Figure 3 is a schematic cross-sectional view of the sealing device to which Embodiment 1 of the present application relates;

[0032] Figure 4 is a plan view of the leaf spring to which Embodiment 1 of the present application relates;

[0033] Figure 5 is a schematic cross-sectional view showing a use state of the sealing device to which Embodiment 1 of the present application relates;

[0034] Figure 6 is a schematic cross-sectional view showing a case where the bent portion of the leaf spring sinks into the resin seal;

[0035] Figure 7 is a graph showing a relationship between a bending angle and a radius of curvature of the bent portion;

[0036] Figure 8 is a schematic cross-sectional view of a sealing device to which Embodiment 2 of the present application relates;

[0037] Figure 9 is a schematic cross-sectional view of a sealing device to which Embodiment 3 of the present application relates;

[0038] Figure 10 is a schematic cross-sectional view of a sealing device to which Embodiment 4 of the present application relates;

[0039] Figure 11 is a schematic cross-sectional view of a sealing device to which the prior art example relates;

[0040] Figure 12 is a schematic cross-sectional view showing a case where a front end of a leaf spring is sunk into a resin-made seal. DETAILED DESCRIPTION

[0041] Hereinafter, a mode for carrying out the present application will be explained in detail exemplarily with reference to the drawings based on embodiments. However, the dimensions, materials, shapes, relative arrangement of the constituent members described in the embodiments are not intended to limit the scope of the present application to these unless specifically specified, and the present application is not limited to these.

[0042] (Embodiment 1)

[0043] Reference Figures 1-7 A sealing device to which Embodiment 1 of the present application relates will be explained. Further, the sealing device to which the present embodiment relates functions to seal an annular gap between a shaft and a housing which relatively move. Further, as specific examples of the relative movement of the shaft and the housing, there can be cited a case where the shaft and the housing relatively rotate, a case where the shaft and the housing relatively reciprocate, a case where the shaft and the housing relatively swing, and a case where these are combined with two or more of them.

[0044] <Sealing device>

[0045] The constitution of the sealing device 100 to which the present embodiment relates will be explained. Figure 1 is a plan view of the sealing device to which Embodiment 1 of the present application relates. Figure 2 is a bottom view of the sealing device to which Embodiment 1 of the present application relates. Figure 3 is a schematic cross-sectional view of the sealing device to which Embodiment 1 of the present application relates. Further, Figure 3 is Figure 2 is a AA cross-sectional view in which hatching is omitted and a part is enlarged. Figure 4 is a plan view of the leaf spring to which Embodiment 1 of the present application relates. Figure 5 is a schematic cross-sectional view showing a use state of the sealing device to which Embodiment 1 of the present application relates. Figure 6is a schematic cross-sectional view showing that the bent portion of the plate spring is sunk into the resin seal. Figure 7 is a graph showing the relationship between the bending angle and the radius of curvature of the bent portion.

[0046] The sealing device 100 according to the present embodiment includes a metal ring 110, a resin seal 120, a plate spring 130, and a metal fixing ring 140 fixed to the inner peripheral surface side of the metal ring 110. The metal ring 110 has a cylindrical portion 111 which is fitted in a state of being in close contact with the inner peripheral surface of the shaft hole provided in the housing 300. Further, an inward flange portion 112 extending to the radially inner side from one end side of the cylindrical portion 111 and a pressing portion 113 formed by bending the other end side of the cylindrical portion 111 to the radially inner side are provided on the metal ring 110. Furthermore, in use of the sealing device 100, the "one end side" described above corresponds to the opposite side (low pressure side (L)) of the sealed region, and the "other end side" described above corresponds to the sealed region side (high pressure side (H)).

[0047] The resin seal 120 is composed of a plate-shaped and ring-shaped resin member. Further, as the resin material used in the present embodiment, PTFE (polytetrafluoroethylene) is employed. The PTFE has characteristics of excellent heat resistance, pressure resistance, and chemical resistance, and less sliding wear. Further, the resin seal 120 according to the present embodiment is configured to be fixed to the metal ring 110 on the outer peripheral side, and to be in close contact with the outer peripheral surface of the shaft 200 in a state of being deformed in a manner of being bent toward the sealed region side (high pressure side (H)) on the inner peripheral side.

[0048] The plate spring 130 is composed of a plate-shaped and ring-shaped metal (for example, SUS (stainless steel)) member. Further, the plate spring 130 is configured to be fixed to the metal ring 110 on the outer peripheral side, and to be deformed in a manner of being bent along the resin seal 120 on the inner peripheral side, and to press the vicinity of the end portion of the inner peripheral side of the resin seal 120 toward the radially inner side. Further, a plurality of inner peripheral side slits 131 extending from the inner peripheral end to the outer peripheral end side are provided on the plate spring 130 at intervals in the circumferential direction. In the present embodiment, the plurality of inner peripheral side slits 131 are provided at equal intervals in the circumferential direction. Further, a plurality of outer peripheral side slits 132 extending from the outer peripheral end to the inner peripheral end side are provided on the plate spring 130 according to the present embodiment at intervals in the circumferential direction. In the present embodiment, the plurality of outer peripheral side slits 132 are provided at equal intervals in the circumferential direction. Furthermore, the inner peripheral side slits 131 and the outer peripheral side slits 132 are alternately provided in the circumferential direction. Further, the plate spring 130 according to the present embodiment has a bent portion 133 which is formed by pre-bending a part of the front end portion on the inner peripheral side of the plate spring 130.

[0049] The retaining ring 140 includes a cylindrical portion 141 fixed to the inner circumferential surface of the metal ring 110, and an inwardly projecting flange portion 142 extending radially inward from one end of the cylindrical portion 141. Furthermore, the metal ring 110 is bent radially inward to form a pressing portion 113, such that when the retaining ring 140 is positioned on the inner circumferential surface of the metal ring 110, the end of the other end of the metal ring 110 (the sealing target area side) abuts against the end of the retaining ring 140. Thus, the outer circumferential ends of the resin seal 120 and the leaf spring 130 are compressed between the inwardly projecting flange portion 112 and the retaining ring 140, thereby fixing these outer circumferential ends of the resin seal 120 and the leaf spring 130 to the metal ring 110.

[0050] <Installation method and usage status of the sealing device>

[0051] Especially referencing Figure 5 The installation method and usage state of the sealing device 100 according to this embodiment will be described. First, the installation method of the sealing device 100 will be described. The sealing device 100, configured as described above, is inserted into the shaft hole provided in the housing 300 and fits into the shaft hole. At this time, the outer peripheral surface of the cylindrical portion 111 of the metal ring 110 in the sealing device 100 is in close contact with the inner peripheral surface of the shaft hole. Furthermore, the shaft 200 from... Figure 5 The left side (opposite to the area to be sealed during use (low-pressure side (L))) is inserted into the right side (the area to be sealed during use (high-pressure side (H))). As a result, the inner circumferential ends of the resin seal 120 and leaf spring 130 are pressed by the shaft 200. Therefore, the resin seal 120 and leaf spring 130 deform in such a way that their inner circumferential sides bend further towards the area to be sealed (high-pressure side (H)) than when compressed between the inward flange 112 and the retaining ring 140. That is, as the shaft 200 is inserted, the resin seal 120 slides freely and comes into close contact with the outer circumferential surface of the shaft 200 while its inner circumferential side is deformed towards the area to be sealed. Furthermore, as the shaft 200 is inserted, the leaf spring 130 deforms along the inner circumferential side of the resin seal 120 and presses the inner circumferential side of the resin seal 120 radially inward.

[0052] As described above, with the shaft 200 inserted, the inner circumferential surface near the front end of the bent portion of the resin seal 120 is in close contact with the outer circumferential surface of the shaft 200. Furthermore, the inner circumferential surface near the front end of the bent portion of the leaf spring 130 is in close contact with the outer circumferential surface near the front end of the bent portion of the resin seal 120. Moreover, utilizing the elastic restoring force of the leaf spring 130, the portion near the front end of the leaf spring 130 presses radially inward against the area near the front end of the bent portion of the resin seal 120.

[0053] <folded portion>

[0054] The folded portion 133 provided on the inner peripheral side of the plate spring 130 will be described in detail. The plate spring 130 according to the present embodiment has the above-described folded portion 133 so that the front end of the inner peripheral side of the plate spring 130 is separated from the outer peripheral surface of the resin seal 120 in a state in which the shaft 200 is inserted. In the present embodiment, the folded portion 133 constitutes a sinkage suppression structure in which the sinkage of the front end of the plate spring 130 toward the resin seal 120 is suppressed. Referring to Figure 3 The dimension setting of the folded portion 133 will be described.

[0055] (1) In a state before the shaft 200 is inserted, the bending angle θ of the folded portion 133 on the resin seal 120 side is set to 30° or more.

[0056] (2) In a state before the shaft 200 is inserted, the radius of curvature R of the folded portion 133 on the resin seal 120 side is set to 0.1 mm or more.

[0057] (3) In a state before the shaft 200 is inserted, when the radial width of the resin seal 120 is set to L and the radial distance between the front end of the inner peripheral side of the plate spring 130 and the front end of the inner peripheral side of the resin seal 120 is set to X, it is set to satisfy 0 < X ÷ L < 0.2.

[0058] (4) In a state before the shaft 200 is inserted, when the radial distance from the front end of the inner peripheral side of the resin seal 120 to the folded portion 133 is set to Y, it is set to satisfy 0.03 < Y ÷ L < 0.3. Note that the "radial distance" does not include the distance of the deviation in the axial direction, and only refers to the distance of the length in the radial direction.

[0059] Referring to Figure 6 and Figure 7 The reasons for setting as in (1) to (4) will be described. Figure 7 is a graph showing the measured values of the bending angle θ of the folded portion 133 provided on the front end of the inner peripheral side of the plate spring 130 and the above-described radius of curvature R when the various folded portions 133 are processed by changing the bending angle θ of the folded portion 133. Note that the graph shows an approximate curve based on the measured values.

[0060] The white circles in the graph indicate measured values when the front end of the inner peripheral side of the plate spring 130 does not sink into the outer peripheral surface of the resin seal 120. In contrast, the black circles in the graph indicate measured values when the front end of the inner peripheral side of the plate spring 130 sinks into the outer peripheral surface of the resin seal 120. As is clear from this, even if the bent portion 133 is provided, if the bending angle θ of the bent portion 133 is small, the front end of the inner peripheral side of the plate spring 130 sinks into the outer peripheral surface of the resin seal 120. Further, as is clear from the graph, by setting the bending angle θ of the bent portion 133 to 30° or more, sinking of the front end of the inner peripheral side of the plate spring 130 into the outer peripheral surface of the resin seal 120 can be suppressed. The above is the reason for the setting as in (1) above.

[0061] The white triangles in the graph indicate measured values when the bent portion of the bent portion 133 does not sink into the outer peripheral surface of the resin seal 120. In contrast, the black triangles in the graph indicate measured values when the bent portion of the bent portion 133 sinks into the outer peripheral surface of the resin seal 120. As is clear from this, even if sinking of the front end of the inner peripheral side of the plate spring 130 into the outer peripheral surface of the resin seal 120 can be suppressed by providing the bent portion 133, when the radius of curvature of the bent portion is small, the bent portion sinks into the outer peripheral surface of the resin seal 120. Further, in the graph, Figure 6 In the graph, a case where the bent portion of the plate spring 130 sinks into the resin seal 120 is shown (refer to T in the graph). Further, as is clear from the graph, by setting the radius of curvature R to 0.1 mm or more, sinking of the bent portion into the outer peripheral surface of the resin seal 120 can be suppressed. The above is the reason for the setting as in (2) above. Further, in the present embodiment, by setting the bending angle θ to 60° or less, the radius of curvature R can be set to 0.1 mm or more. As is clear from this, if 30° < θ < 60° is set, sinking of the front end of the inner peripheral side of the plate spring 130 into the outer peripheral surface of the resin seal 120 can be suppressed, and sinking of the bent portion into the outer peripheral surface of the resin seal 120 can also be suppressed.

[0062] Further, the reason for the setting as in (3) is to suppress direct contact of the front end of the inner peripheral side of the plate spring 130 with the shaft 200, and to stably exert the original function of the plate spring 130 of pressing the resin seal 120. Further, the reason for the setting as in (4) is to more reliably separate the front end of the inner peripheral side of the plate spring 130 from the outer peripheral surface of the resin seal 120, and to stably exert the original function of the plate spring 130 of pressing the resin seal 120.

[0063] <Advantages of the sealing device according to the present embodiment>

[0064] According to the sealing device 100 according to the present embodiment, the plate spring 130 is configured so that the leading end on the inner peripheral side thereof is separated from the outer peripheral surface of the resin seal 120 by having the bent portion 133. Thus, the leading end on the inner peripheral side of the plate spring 130 is prevented from sinking into the resin seal 120 at the time of insertion of the shaft 200 or the like. Therefore, the resin seal 120 can be prevented from being damaged by the plate spring 130. Further, by setting the dimensions of each portion as described above, the damage to the resin seal 120 can be more reliably prevented.

[0065] Further, the sealing device 100 according to the present embodiment employs a structure having the metal ring 110 having the cylindrical portion 111 that is fitted in a state of being in close contact with the inner peripheral surface of the shaft hole provided in the housing 300. Thus, even in the case where the housing 300 is composed of a casting (for example, a casting made of aluminum), sufficient sealability can be obtained between the outer peripheral surface of the metal ring 110 and the inner peripheral surface of the shaft hole. That is, even if there are a plurality of minute recesses like casting nests on the inner peripheral surface of the shaft hole of the housing 300, the sealability can be exerted.

[0066] Further, the sealing device 100 according to the present embodiment is composed of a plate-shaped and ring-shaped resin member, and employs a configuration having the resin seal 120 that is fixed to the metal ring 110 on the outer peripheral side thereof and is in close contact with the outer peripheral surface of the shaft 200 in a state of being deformed in a manner of being bent toward the seal target region side on the inner peripheral side thereof. Thus, compared with the case where a seal made of a rubber-like elastic body is used, the heat resistance and the like are excellent, and the sliding wear can be reduced.

[0067] Further, the sealing device 100 according to the present embodiment is provided with the plate spring 130 that presses the inner peripheral side of the resin seal 120 toward the radially inner side. Thus, even if fatigue is generated in the resin seal 120 itself due to long-time use in a high-temperature environment, stable sealability can be maintained for a long time.

[0068] (Embodiment 2)

[0069] Figure 8 Embodiment 2 of the present application is shown. In the present embodiment, a configuration in which bending processing is performed in a manner of being bent toward the seal target region side at a position in the plate spring that is more radially outward than the bent portion is described. Since the other structures and effects are the same as those of Embodiment 1, the same reference numerals are assigned to the same constituent parts, and the description thereof is omitted.

[0070] Even in the sealing device 100 according to the present embodiment, as in the case of the above-described embodiment 1, the metal ring 110, the resin seal 120, the plate spring 130, and the metal fixing ring 140 fixed to the inner circumferential surface of the metal ring 110 are included. The configuration of the metal ring 110, the resin seal 120, and the fixing ring 140 is the same as that of the above-described embodiment 1, and thus the description thereof is omitted.

[0071] In addition, in the present embodiment, the plate spring 130 also has a bent portion 133 that is bent in advance by bending a part of the front end portion on the inner circumferential side of the plate spring 130. Further, as for the dimensional settings (1) and (2) shown in the embodiment 1, the same as the above-described embodiment 1 is applied.

[0072] Also, in the present embodiment, as for the plate spring 130, at a position more radially outward than the bent portion 133, bending processing is performed in advance in a manner of bending toward the sealing target region side (right side in the drawing) of the sealing device 100 at the time of use (refer to the bent portion 134 in the drawing). Only this point is different from the case of the above-described embodiment 1. As explained in the above-described embodiment 1, by inserting the shaft 200 in the sealing device 100, the inner circumferential side of the plate spring 130 is deformed in a manner of bending toward the sealing target region side (high pressure side (H)).

[0073] Here, in order to stabilize the pressing force generated by the plate spring 130 for a long period of time, it is desirable that the amount of deformation of the plate spring 130 that occurs with the insertion of the shaft 200 is included in the elastic region. That is, it is desirable that plastic deformation does not occur. In the case of the above-described embodiment 1, since the amount of deformation of the plate spring 130 that occurs with the insertion of the shaft 200 is relatively large, it is sometimes not possible to include the amount of deformation in the elastic region. Therefore, in the present embodiment, by performing bending processing on the inner circumferential side of the plate spring 130, a certain degree of plastic deformation is generated in advance. Thereby, it is possible to reduce the amount of deformation of the plate spring 130 that occurs with the insertion of the shaft 200, and it is possible to include the amount of deformation that occurs with the insertion of the shaft 200 in the elastic region.

[0074] Even in the sealing device 100 configured as described above, the same effects as in the case of the above-described embodiment 1 can be obtained. Further, by performing bending processing in advance on the part of the inner circumferential side of the plate spring 130 and the part of the inner circumferential side of the resin seal 120, it is also possible to insert the shaft 200 from the sealing target region side (high pressure side (H)) at the time of use toward the opposite side (low pressure side (L)) of the sealing target region. In this case, in the state in which the bending processing is performed on the resin seal 120, it is of course necessary to set the inner diameter of the inner circumferential end of the resin seal 120 (the inner diameter of the smallest part) to be larger than the outer diameter of the front end of the shaft 200.

[0075] (Embodiment 3)

[0076] Figure 9 An embodiment 3 of the present application is shown. In this embodiment, a structure of the sinkage suppression structure of the front end of the plate spring is shown as a structure different from that of the above-described embodiment 1. Since other structures and actions are the same as those of embodiment 1, the same components are denoted by the same symbols, and the description thereof is omitted.

[0077] Figure 9 is a schematic cross-sectional view of the sealing device to which the embodiment 3 of the present application relates. Furthermore, Figure 9 corresponding to the AA cross-sectional view of Figure 2 in the above-described embodiment 1 is shown. In the sealing device 100 to which the present embodiment relates, as well as in the case of the above-described embodiment 1, a metal ring 110, a resin sealing member 120, a plate spring 130, and a metal fixing ring 140 fixed to the inner peripheral surface of the metal ring 110 are included. The structures of the metal ring 110, the resin sealing member 120, and the fixing ring 140 are the same as those of the above-described embodiment 1, and thus the description thereof is omitted.

[0078] Furthermore, in the present embodiment, the plate spring 130 has a bent portion 133X that is formed by previously bending a part of the front end portion on the inner peripheral side of the plate spring 130. The bent portion 133X is bent in such a manner as to fold back the front end of the plate spring 130. Only this point is different from the case of the above-described embodiment 1. As described above, in the present embodiment, the sinkage suppression structure is constituted by the bent portion 133X. In the present embodiment, as explained in the above-described embodiment 1, by inserting the shaft 200 into the sealing device 100, the inner peripheral side of the plate spring 130 is deformed in such a manner as to bend toward the sealing target region side (high pressure side (H)).

[0079] In the sealing device 100 constituted as described above, the front end of the plate spring 130 is folded back by the bent portion 133X, and thus the front end of the plate spring 130 does not sink into the resin sealing member 120. In addition, the bent portion 133X itself also does not sink into the resin sealing member 120. Furthermore, in the present embodiment, as shown in the above-described embodiment 2, a structure in which, at a position radially outward of the bent portion 133X, a bending process is performed in such a manner as to bend toward the sealing target region side (the right side in the drawing) of the sealing device 100 at the time of use can also be employed.

[0080] (Embodiment 4)

[0081] Figure 10 An embodiment 4 of the present application is shown. In this embodiment, a structure of the sinkage suppression structure of the front end of the plate spring is shown as a structure different from that of the above-described embodiment 1. Since other structures and actions are the same as those of embodiment 1, the same components are denoted by the same symbols, and the description thereof is omitted.

[0082] Figure 10 is a schematic cross-sectional view of a sealing device to which Embodiment 4 of the present application relates. Furthermore, Figure 10 corresponds to the AA cross-sectional view of the sealing device shown in Embodiment 1, the hatching is omitted, and a portion is shown enlarged. In the sealing device 100 of the present embodiment, as well as in the case of Embodiment 1 described above, a metal ring 110, a resin seal 120, a leaf spring 130, and a metal fixing ring 140 fixed to the inner peripheral surface of the metal ring 110 are included. The configurations of the metal ring 110, the resin seal 120, and the fixing ring 140 are the same as in Embodiment 1 described above, and thus the description thereof is omitted. Figure 2

[0083] Also, in the present embodiment, a sinking suppression structure is configured by providing a protection portion 133Y for covering the front end of the leaf spring 130 at the front end of the leaf spring 130. Only this point is different from the case of Embodiment 1 described above. The protection portion 133Y can be configured, for example, by adhering a resin material or the like to the front end of the leaf spring 130. In the present embodiment, as explained in Embodiment 1 described above, by inserting the shaft 200 into the sealing device 100, the inner peripheral side of the leaf spring 130 is deformed in a manner of bending toward the sealing target region side (high pressure side (H)).

[0084] In the sealing device 100 configured as described above, since the front end of the leaf spring 130 is covered by the protection portion 133Y, the front end of the leaf spring 130 does not sink into the resin seal 120. In addition, by appropriately setting the shape and material of the protection portion 133Y, the protection portion 133Y also does not sink into the resin seal 120. Furthermore, in the present embodiment, as shown in Embodiment 2 described above, a configuration in which bending processing is performed in advance in a manner of bending toward the sealing target region side (right side in the drawing) of the sealing device 100 at a position radially outward of the protection portion 133Y can also be employed.

[0085] Symbol Explanation

[0086] 100: Sealing device;

[0087] 110: Metal ring;

[0088] 111: Cylinder portion;

[0089] 112: Inward flange portion;

[0090] 113: Pressing portion;

[0091] 120: Resin seal;

[0092] 130: Leaf spring;

[0093] 131: Inner peripheral side slit; ​

[0094] 132: outer peripheral side slit;

[0095] 133: bent portion;

[0096] 133X: bent portion;

[0097] 133Y: protection portion;

[0098] 134: bent portion;

[0099] 140: fixing ring;

[0100] 141: cylindrical portion;

[0101] 142: inward flange portion;

[0102] 200: shaft;

[0103] 300: housing.

Claims

1. A seal device that seals an annular gap between an axially moving shaft and a housing, the seal device characterized by comprising: a metal ring having a cylindrical portion that fits with an inner peripheral surface of a shaft hole provided in the housing, an inward flange portion that extends from one end side of the cylindrical portion to a radially inner side, and a pressing portion that is formed by bending the other end side of the cylindrical portion to the radially inner side; a resin seal member that is composed of a plate-shaped and annular resin portion; a leaf spring that is composed of a plate-shaped and annular metal portion; and a retainer ring that is fixed to an inner peripheral surface side of the metal ring and that abuts against the pressing portion, and wherein in the seal device, an end portion of the resin seal member on an outer peripheral side and an end portion of the leaf spring on an outer peripheral side are compressed between the inward flange portion and the retainer ring so that the outer peripheral side of the resin seal member and the outer peripheral side of the leaf spring are fixed to the metal ring, the resin seal member has a bent portion on an inner peripheral side that is configured to bend toward a seal target region side during insertion of the shaft into the seal device, the leaf spring has a pressing portion on an inner peripheral side that is configured to bend and deform along the resin seal member during insertion of the shaft into the seal device, to press a bent portion of the resin seal member to a radially inner side using an elastic restoring force of the leaf spring, and a protection portion that covers a front end of the leaf spring is provided at the front end of the leaf spring to constitute a sinkage suppression structure, and the sinkage suppression structure toward which sinkage of the resin seal member is suppressed is constituted by the protection portion that covers the front end of the leaf spring so that the front end of the leaf spring on the inner peripheral side is separated from an outer peripheral surface of the resin seal member in a state in which the shaft is inserted. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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