JP3760327B2

JP3760327B2 - Sealing device

Info

Publication number: JP3760327B2
Application number: JP15045397A
Authority: JP
Inventors: 浩山内
Original assignee: Nok Corp
Current assignee: Nok Corp
Priority date: 1997-05-23
Filing date: 1997-05-23
Publication date: 2006-03-29
Anticipated expiration: 2017-05-23
Also published as: JPH10325470A

Description

【０００１】
【発明の属する技術分野】
本発明は、各種油圧機器の軸封部に使用される密封装置に関し、特に、高圧流体を密封する密封装置に関する。
【０００２】
【従来の技術】
従来、この種の密封装置としては、図４に示すようなオイルシール１０１がある。オイルシール１０１は、被覆部１０２と金属環１０３とを一体に形成したものである。オイルシール１０１では、截頭円錐筒形状の保持器１０４とシールリップ部１０５とが非接着に構成されており、保持器１０４は径方向に非拘束の状態となっている。
【０００３】
実際の使用条件では、取付偏心，軸偏心等が発生するとともに、密封対象流体の圧力による軸へのシールリップ部１０５の押し付けも作用する。
【０００４】
【発明が解決しようとする課題】
このような軸偏心が発生した状態を図５に示す。偏心マイナス側（図５の軸線下側）では、シールリップ部１０５の倒れ込み及びシールリップ部１０５に作用する圧力で、無偏心時の保持器１０４（図５の破線部）の筒部端部１０４ａに過大な力が作用する。一方、偏心プラス側（図５の軸線上側）では、シールリップ部１０５と軸１０６とに隙間が発生する方向に変形する。保持器１０４に軸線垂直方向に作用する力は、偏心プラス側よりも偏心マイナス側の方が大きい。従って、実際には、保持器１０４（図５の実線部）は偏心プラス側へ移動し、所期の位置に保つことができなくなる。
【０００５】
このように、保持器１０４が当初の機能を発揮できないため、シールリップ部１０５の付け根部１０５ａの変形が大きくなるともに圧力（一般には変動圧）の作用により、シールリップ部１０５の破損及び軸１０６とシールリップ部１０５との接触状態の変化による密封性能の低下が引き起こされる。
【０００６】
尚、保持器１０４のフランジ部１０４ａの外径側の被覆部１０２による保持器１０４の径方向の拘束は、シール体がゴム等の弾性体製であり、ゴムの劣化によるへたりがあるために有効なものではない。
【０００７】
また、シールリップ部１０５に高圧が作用した場合には、保持器１０４の強度不足によるたわみが生じるので、軸１０６とシールリップ部１０５との接触状態が不安定となり、密封性能の低下が引き起こされる。
【０００８】
本発明は、かかる従来技術の課題を解決するためになされたものであって、その目的とするところは、軸とシールリップとの接触状態を安定させ、シールリップの破損の防止と密封性能の向上を図ることにある。
【０００９】
【問題点を解決するための手段】
上記目的を達成するために、本発明にあっては、ハウジングと同心的に組み付けられた軸との間を密封する密封装置であって、前記ハウジングに組み付けられる補強環を有し、該補強環は前記ハウジングに組み付けられる筒部と、該筒部の反密封対象流体側端部から内径方向に延びるフランジ部と、該フランジ部の内径端部から密封対象流体側に延びる支持環支持部が設けられ、前記補強環に一体に設けられ、前記軸に密封接触するゴム状弾性体製のシールリップを有し、
該シールリップの反密封対象流体側であって、密封対象流体側へ向かって延びる筒部と、該筒部の密封対象流体側端部から軸線に対し直角に内径側に延び、その内径側端部が平面であると共に、前記支持環支持部の軸方向端部と間隙を有している内向きフランジ部とからなる、前記支持環支持部との間に相対移動可能に装着されて該シールリップを支持する支持環と、前記支持環に設けられた内径側端部は前記シールリップの反密封対象流体側縁部よりも内径側に形成し、前記支持環の筒部は前記補強環の内径部と嵌合することにより径方向の移動を規制され、密封対象流体の圧力による前記シールリップの変形に伴なう支持環の変形が抑制されることを特徴とする。
【００１０】
このようにすれば、同心的に組み付けられた２部材間で偏心が生じた場合に、支持環と補強環とが嵌合させてあり、支持環の径方向の移動が補強環によって規制されるので、シールリップと支持環とが相対移動可能であっても、２部材の一方の部材とシールリップとの接触状態が安定し、密封性能が向上する。また、支持環のシールリップへのくい込み等によるシールリップの破損防止を図ることができる。
【００１１】
第２の発明は第１の発明において、前記支持環に設けられた内径側端部を前記シールリップの反密封対象流体側縁部よりも内径側に形成することを特徴とする。
【００１２】
前記支持環に設けられた内径側端部を前記シールリップの反密封対象流体側縁部よりも内径側に形成すれば、同心的に組み付けられた２部材間で偏心が生じた場合に、シールリップと支持環とが相対移動可能であっても、支持環のリールリップへのくい込み等によるシールリップの破損防止を図ることができる。
【００１４】
このように、支持環の反シールリップ側すなわち密封対象流体の圧力によるシールリップの変形を受ける側を支持する補強環支持部を設けることにより、支持環の剛性が向上し、密封対象流体の圧力によるシールリップの変形に伴う支持環の変形が抑制され、シールリップの変形が小さくなるので、２部材の一方の部材とシールリップとの接触状態が安定し、密封性能が向上する。
【００１５】
【発明の実施の形態】
以下、本発明を図示の実施の形態に基づいて説明する。
【００１６】
（第１の実施形態）
図１に本発明の第１の実施形態に係る密封装置としてのオイルシール１を示す。
【００１７】
オイルシール１は、主として、断面略Ｊ字形状の金属環３，ゴム状弾性体製の被覆部２及び環状の保持器４からなり、従来技術に係るオイルシール１０１と同様に同心的に組み付けられたハウジング（図示せず）と軸（図示せず）との環状隙間を密封する。
【００１８】
補強環としての金属環３は、軸方向に延びる筒部３１，筒部３１の反密封対象流体側（Ａ）端部から内径方向に延びるフランジ部３２及びフランジ部３２の内径側端部から密封対象流体側（Ｏ）に延びる内径部３３からなる。
【００１９】
被覆部２は金属環３に一体に形成されている。金属環３の筒部３１の密封対象流体側（Ｏ）端部から筒部３１の内周及び外周側を覆い、反密封対象流体側（Ａ）端部から連続的にフランジ部３２の密封対象流体側（Ｏ）及び反密封対象流体側（Ａ）を内径側まで覆う。被覆部２の反密封対象流体側（Ａ）は金属環３の内径部３３の付け根部分までを覆っており、内径側の端部には内径方向反密封対象流体側（Ａ）に延びて軸（図示せず）に摺動密封するダストリップ部２１が設けられている。被覆部２の密封対象流体側（Ｏ）は金属環３のフランジ部３２の内径側端部近傍までを覆っており、内径側の端部には内径方向密封対象流体側（Ｏ）に延びて軸に摺動密封するシールリップとして主シールリップ部２２が設けられている。主シールリップ部２２の付け根部分の内径側には、保持器４が嵌り込む凹部２３が形成されている。また、主シールリップ部２２の先端部２２ａの外径側に設けられた溝２４には先端部２２ａを軸側に押圧するための環状のスプリング５が装着されている。
【００２０】
支持環としての保持器４は、断面略Ｓ字形状をなし、密封対象流体側（Ｏ）へ向かって軸方向から若干内径方向に延びる筒部４１，筒部４１の密封対象流体側（Ｏ）端部から内径側に延びる内向きフランジ部４２及び筒部４１の反密封対象流体側（Ａ）端部から外径方向に延びる外向きフランジ部４３からなる。金属環３の内径部３３はフランジ部３２の内径側端部から密封対象流体側（Ｏ）へ向かって軸方向から若干内径方向に形成されており、保持器４の筒部４１と嵌合している。外向きフランジ部４３の反密封対象流体側（Ａ）端面４３ａは、金属環３のフランジ部３２の密封対象流体側（Ｏ）端面３２ａに当接している。このように、本実施形態では金属環３の内径部３３及びフランジ部３２が、支持環としての保持器を内径側及び反密封対象流体側（Ａ）から支持する支持環支持部を構成する。保持器４は主シールリップ部２２の付け根部分の内径側の凹部２３に装着され、外径側を被覆部２に覆われているが、保持器４と被覆部２とは接着されておらず相対移動可能である。また、保持器４の内向きフランジ部４２の内径側端部４２ａは主シールリップ部２２の反密封対象流体側（Ａ）縁部よりも若干内径側に位置する。このように保持器４の内向きフランジ部４２の内径側端部４２ａを主シールリップ部の反密封対象流体側（Ａ）縁部よりも若干内径側に形成しておけば、主シールリップ部２２が内向きフランジ部４２の内径側にくい込んで損傷することがない。保持器４と金属環３とは密接に嵌合している場合に限られず、若干の隙間を有して嵌り合っていてもよい。
【００２１】
このように、外径側を被覆部２を介してハウジングに固定保持されて径方向の移動を規制された金属環３の内径部３３と保持器４とを嵌合させることにより、保持器の径方向の移動が規制されるので、取付偏心，軸偏心等が生じても、軸と主シールリップ部２２との接触状態が不安定化することはない。従って、主シールリップ部２２の破損の防止及び密封性能の向上を図ることができる。
【００２２】
また、保持器４の反密封対象流体側（Ａ）及び内径側が金属環３のフランジ部３２及び内径部３３によって支持されて剛性が向上し、密封対象流体の圧力による保持器の変形が抑制されるので、主シールリップ部２２の変形が小さくなり、軸と主シールリップ部２２との接触状態が安定化する。従って、密封性能が向上する。
【００２３】
（第２の実施形態）
図２に本発明の第２の実施形態を示す。
【００２４】
本実施形態に係るオイルシール６は、保持器７の形状，金属環３の内径部３４の形状及び被覆部２の主シールリップ部２２の付け根部分の内径側の凹部２５の形状を除いては第１の実施形態と同様であるので、同様の符号を付して説明を省略する。
【００２５】
オイルシール６の保持器７は、軸方向に延びる筒部７１と、筒部７１の密封対象流体側（Ｏ）端部から内径側に延びる内向きフランジ部７２とからなる。筒部７１の反密封対象流体側（Ａ）端面７１ａは金属環３の密封対象流体側（Ｏ）端面３２ａに当接している。保持器７は、内径側で筒部３４に沿うように軸方向に形成された金属環３の内径部３４と嵌合している。本実施形態では、金属環３の内径部３４及びフランジ部３２が、支持環としての保持器７を内径側及び反密封対象流体側（Ａ）から支持する支持環支持部を構成する。保持器７と金属環３とは密接に嵌合している場合に限られず、若干の隙間を有して嵌り合っていてもよい。保持器７は主シールリップ部２２の付け根部分の内径側の凹部２５に装着され、外径側を被覆部２によって覆われているが、保持器７と被覆部２とは接着されておらず、相対移動可能である。また、保持器７の内向きフランジ部７２の内径側端部７２ａは主シールリップ部２２の反密封対象流体側（Ａ）縁部よりも若干内径側に位置する。このように保持器７の内向きフランジ部７２の内径側端部７２ａを主シールリップ部２２の反密封対象流体側（Ａ）縁部よりも若干内径側に形成しておけば、主シールリップ部２２が内向きフランジ部７２の内径側にくい込まれて損傷することがない。
【００２６】
このように、外径側を被覆部２を介してハウジングに固定保持されて径方向の移動を規制された金属環３の内径部３４と保持器７とを嵌合させることにより、保持器７の径方向の移動が規制されるので、取付偏心，軸偏心等が生じても、軸と主シールリップ部２２との接触状態が不安定化することはない。従って、主シールリップ部２２の破損の防止及び密封性能の向上を図ることができる。
【００２７】
また、保持器７の反密封対象流体側（Ａ）及び内径側が金属環３のフランジ部３２及び内径部３４によって支持されて剛性が向上し、密封対象流体の圧力による保持器の変形が抑制されるので、主シールリップ部２２の変形が小さくなり、軸と主シールリップ部２２との接触状態が安定化する。従って、密封性能が向上する。
【００３２】
【発明の効果】
第１の発明によれば、同心的に組み付けられた２部材間で偏心が生じた場合に、支持環の径方向の移動が補強環によって規制されるので、シールリップと支持環とが相対移動可能であっても、２部材の一方の部材とシールリップとの接触状態が安定し、密封性能が向上する。また、支持環のシールリップへのくい込み等によるシールリップの破損防止を図ることができる。
【００３３】
第２の発明によれば、支持環と補強環とが嵌合し、支持環の径方向の移動が規制されるので、同心的に組み付けられた２部材間で偏心が生じた場合に、シールリップと支持環とが相対移動可能であっても、２部材の一方の部材とシールリップとの接触状態が安定し、密封性能が向上する。また、支持環のリールリップへのくい込み等によるシールリップの破損防止を図ることができる。
【図面の簡単な説明】
【図１】図１は本発明の第１の実施形態に係るオイルシールの構成を示す断面図である。
【図２】図２は本発明の第２の実施形態に係るオイルシールの構造を示す半断面図である。
【図３】図３は従来技術に係るオイルシールの構成を示す半断面図である。
【図４】図４は従来技術に係るオイルシールの問題点を説明するための図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device used for a shaft seal portion of various hydraulic devices, and more particularly to a sealing device that seals a high-pressure fluid.
[0002]
[Prior art]
Conventionally, as this type of sealing device, there is an oil seal 101 as shown in FIG. The oil seal 101 is formed by integrally forming a covering portion 102 and a metal ring 103. In the oil seal 101, the truncated conical cylinder-shaped cage 104 and the seal lip portion 105 are configured to be non-bonded, and the cage 104 is in an unconstrained state in the radial direction.
[0003]
Under actual use conditions, mounting eccentricity, shaft eccentricity, and the like occur, and the seal lip 105 is pressed against the shaft by the pressure of the fluid to be sealed.
[0004]
[Problems to be solved by the invention]
FIG. 5 shows a state in which such shaft eccentricity has occurred. On the eccentric minus side (below the axis in FIG. 5), the cylinder lip 104a of the cage 104 (dashed line in FIG. 5) when not eccentric due to the fall of the seal lip 105 and the pressure acting on the seal lip 105. Excessive force acts on the. On the other hand, on the eccentric plus side (the upper side of the axis in FIG. 5), the seal lip portion 105 and the shaft 106 are deformed in a direction in which a gap is generated. The force acting on the cage 104 in the direction perpendicular to the axis is greater on the eccentric minus side than on the eccentric plus side. Therefore, actually, the cage 104 (solid line portion in FIG. 5) moves to the eccentric plus side and cannot be maintained at the intended position.
[0005]
As described above, since the cage 104 cannot perform the original function, the base portion 105a of the seal lip portion 105 is greatly deformed and the seal lip portion 105 is damaged due to the action of pressure (generally fluctuating pressure). The sealing performance is deteriorated due to a change in the contact state between the lip portion 105 and the sealing lip portion 105.
[0006]
In addition, the radial restriction of the cage 104 by the covering portion 102 on the outer diameter side of the flange portion 104a of the cage 104 is because the seal body is made of an elastic body such as rubber, and there is a sag due to deterioration of the rubber. It is not valid.
[0007]
In addition, when a high pressure is applied to the seal lip portion 105, the cage 104 is deflected due to insufficient strength, so that the contact state between the shaft 106 and the seal lip portion 105 becomes unstable, and the sealing performance is reduced. .
[0008]
The present invention has been made to solve the problems of the prior art, and the object of the present invention is to stabilize the contact state between the shaft and the seal lip, to prevent damage to the seal lip and to improve the sealing performance. The goal is to improve.
[0009]
[Means for solving problems]
In order to achieve the above object, according to the present invention, there is provided a sealing device for sealing between a housing and a shaft assembled concentrically, the sealing device having a reinforcing ring assembled to the housing, and the reinforcing ring Is provided with a cylindrical portion assembled to the housing, a flange portion extending in the inner diameter direction from the end portion on the anti-sealing target fluid side of the cylindrical portion, and a support ring support portion extending from the inner diameter end portion of the flange portion toward the sealing target fluid side. A seal lip made of a rubber-like elastic body provided integrally with the reinforcing ring and in sealing contact with the shaft;
A cylinder portion extending toward the fluid to be sealed on the anti-sealing fluid side of the seal lip, and an inner diameter side end extending from the sealing fluid side end of the cylinder to the inner diameter side at right angles to the axis. The seal is mounted on the support ring support portion so as to be movable relative to the support ring support portion. The seal ring has a flat surface and includes an axial end portion of the support ring support portion and an inward flange portion having a gap. A support ring that supports the lip and an inner diameter side end provided on the support ring are formed on the inner diameter side of the seal lip on the side opposite to the fluid to be sealed, and the cylindrical portion of the support ring is formed on the reinforcing ring. The radial movement is restricted by fitting with the inner diameter portion, and the deformation of the support ring due to the deformation of the seal lip due to the pressure of the fluid to be sealed is suppressed.
[0010]
In this way, when eccentricity occurs between the two members assembled concentrically, the support ring and the reinforcement ring are fitted, and the radial movement of the support ring is restricted by the reinforcement ring. Therefore, even if the seal lip and the support ring are relatively movable, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved. Further, it is possible to prevent the seal lip from being damaged due to the biting of the support ring into the seal lip.
[0011]
The second invention is characterized in that, in the first invention, an inner diameter side end portion provided in the support ring is formed on an inner diameter side of an anti-sealing target fluid side edge portion of the seal lip .
[0012]
If the inner diameter side end provided on the support ring is formed on the inner diameter side with respect to the anti-sealing target fluid side edge of the seal lip , a seal is formed when eccentricity occurs between two concentrically assembled members. Even if the lip and the support ring can move relative to each other, it is possible to prevent the seal lip from being damaged due to the biting of the support ring into the reel lip.
[0014]
As described above, by providing the reinforcing ring support portion that supports the anti-seal lip side of the support ring, that is, the side that receives the deformation of the seal lip due to the pressure of the fluid to be sealed, the rigidity of the support ring is improved and the pressure of the fluid to be sealed is increased. The deformation of the support ring accompanying the deformation of the seal lip due to is suppressed, and the deformation of the seal lip becomes small. Therefore, the contact state between one member of the two members and the seal lip is stabilized, and the sealing performance is improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiments.
[0016]
(First embodiment)
FIG. 1 shows an oil seal 1 as a sealing device according to a first embodiment of the present invention.
[0017]
The oil seal 1 mainly includes a metal ring 3 having a substantially J-shaped cross section 3, a covering portion 2 made of a rubber-like elastic body, and an annular cage 4, and is concentrically assembled in the same manner as the oil seal 101 according to the prior art. The annular gap between the housing (not shown) and the shaft (not shown) is sealed.
[0018]
The metal ring 3 as the reinforcing ring is sealed from the cylindrical portion 31 extending in the axial direction, the flange portion 32 extending in the inner diameter direction from the anti-sealing target fluid side (A) end portion of the cylindrical portion 31, and the inner diameter side end portion of the flange portion 32. It consists of an inner diameter part 33 extending to the target fluid side (O).
[0019]
The covering portion 2 is formed integrally with the metal ring 3. Covering the inner and outer peripheral sides of the cylindrical portion 31 from the end of the sealing target fluid side (O) of the cylindrical portion 31 of the metal ring 3, and continuously sealing the flange portion 32 from the end of the anti-sealing target fluid side (A) The fluid side (O) and the anti-sealing target fluid side (A) are covered to the inner diameter side. The anti-sealing target fluid side (A) of the covering portion 2 covers up to the base portion of the inner diameter portion 33 of the metal ring 3, and the inner diameter side end portion extends to the inner diameter direction anti-sealing target fluid side (A) and has a shaft. A dust lip 21 is provided for sliding and sealing (not shown). The sealing target fluid side (O) of the covering portion 2 covers the vicinity of the inner diameter side end of the flange portion 32 of the metal ring 3, and the inner diameter end extends to the inner diameter direction sealing target fluid side (O). A main seal lip portion 22 is provided as a seal lip that slides and seals on the shaft. On the inner diameter side of the base portion of the main seal lip portion 22, a recess 23 into which the cage 4 is fitted is formed. Further, an annular spring 5 for pressing the distal end portion 22a to the shaft side is attached to the groove 24 provided on the outer diameter side of the distal end portion 22a of the main seal lip portion 22.
[0020]
The retainer 4 as a support ring has a substantially S-shaped cross section, and extends from the axial direction toward the sealed fluid side (O) slightly in the inner diameter direction, and the sealed fluid side (O) of the tubular portion 41. The inward flange portion 42 extends from the end portion toward the inner diameter side, and the outward flange portion 43 extends in the outer diameter direction from the anti-sealing target fluid side (A) end portion of the cylindrical portion 41. The inner diameter portion 33 of the metal ring 3 is formed in the inner diameter direction slightly from the axial direction from the inner diameter side end portion of the flange portion 32 toward the fluid to be sealed (O), and is fitted to the cylindrical portion 41 of the cage 4. ing. The anti-sealing target fluid side (A) end surface 43 a of the outward flange portion 43 is in contact with the sealing target fluid side (O) end surface 32 a of the flange portion 32 of the metal ring 3. Thus, in this embodiment, the inner diameter part 33 and the flange part 32 of the metal ring 3 constitute a support ring support part that supports the cage as a support ring from the inner diameter side and the anti-sealing target fluid side (A). The cage 4 is mounted in a recess 23 on the inner diameter side of the base portion of the main seal lip portion 22, and the outer diameter side is covered with the covering portion 2, but the cage 4 and the covering portion 2 are not bonded. Relative movement is possible. Further, the inner diameter side end portion 42 a of the inward flange portion 42 of the cage 4 is located slightly on the inner diameter side with respect to the anti-sealing target fluid side (A) edge portion of the main seal lip portion 22. Thus, if the inner diameter side end portion 42a of the inward flange portion 42 of the cage 4 is formed slightly on the inner diameter side from the anti-sealing target fluid side (A) edge portion of the main seal lip portion, the main seal lip portion Therefore, the inner flange 22 is not damaged by the inner diameter side of the inward flange portion 42. The cage 4 and the metal ring 3 are not limited to being closely fitted, and may be fitted with a slight gap.
[0021]
In this way, by fitting the retainer 4 with the inner diameter portion 33 of the metal ring 3 whose outer diameter side is fixedly held by the housing via the covering portion 2 and whose radial movement is restricted, the retainer 4 is fitted. Since the movement in the radial direction is restricted, the contact state between the shaft and the main seal lip portion 22 does not become unstable even if mounting eccentricity, shaft eccentricity, or the like occurs. Therefore, it is possible to prevent damage to the main seal lip portion 22 and improve the sealing performance.
[0022]
Further, the anti-sealing target fluid side (A) and the inner diameter side of the cage 4 are supported by the flange portion 32 and the inner diameter portion 33 of the metal ring 3 to improve rigidity, and deformation of the cage due to the pressure of the fluid to be sealed is suppressed. Therefore, the deformation of the main seal lip portion 22 is reduced, and the contact state between the shaft and the main seal lip portion 22 is stabilized. Accordingly, the sealing performance is improved.
[0023]
(Second Embodiment)
FIG. 2 shows a second embodiment of the present invention.
[0024]
The oil seal 6 according to the present embodiment except for the shape of the cage 7, the shape of the inner diameter portion 34 of the metal ring 3, and the shape of the concave portion 25 on the inner diameter side of the base portion of the main seal lip portion 22 of the covering portion 2. Since it is the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0025]
The cage 7 of the oil seal 6 includes a cylindrical portion 71 extending in the axial direction, and an inward flange portion 72 extending from the sealing target fluid side (O) end of the cylindrical portion 71 toward the inner diameter side. The anti-sealing target fluid side (A) end surface 71 a of the cylindrical portion 71 is in contact with the sealing target fluid side (O) end surface 32 a of the metal ring 3. The cage 7 is fitted to the inner diameter portion 34 of the metal ring 3 formed in the axial direction so as to follow the cylindrical portion 34 on the inner diameter side. In the present embodiment, the inner diameter portion 34 and the flange portion 32 of the metal ring 3 constitute a support ring support portion that supports the cage 7 as a support ring from the inner diameter side and the anti-sealing target fluid side (A). The cage 7 and the metal ring 3 are not limited to being closely fitted, and may be fitted with a slight gap. The cage 7 is mounted in a recess 25 on the inner diameter side of the base portion of the main seal lip portion 22, and the outer diameter side is covered with the covering portion 2, but the cage 7 and the covering portion 2 are not bonded. The relative movement is possible. Further, the inner diameter side end 72 a of the inward flange portion 72 of the cage 7 is located slightly on the inner diameter side with respect to the anti-sealing target fluid side (A) edge of the main seal lip portion 22. Thus, if the inner diameter side end portion 72a of the inward flange portion 72 of the cage 7 is formed slightly on the inner diameter side with respect to the anti-sealing target fluid side (A) edge portion of the main seal lip portion 22, the main seal lip The portion 22 does not get caught and damaged by the inner diameter side of the inward flange portion 72.
[0026]
In this manner, the cage 7 is fitted by fitting the inner diameter portion 34 of the metal ring 3 whose outer diameter side is fixedly held in the housing via the covering portion 2 and whose movement in the radial direction is restricted, and the cage 7. Therefore, even if mounting eccentricity, shaft eccentricity, or the like occurs, the contact state between the shaft and the main seal lip portion 22 does not become unstable. Therefore, it is possible to prevent damage to the main seal lip portion 22 and improve the sealing performance.
[0027]
Further, the anti-sealing target fluid side (A) and the inner diameter side of the cage 7 are supported by the flange portion 32 and the inner diameter portion 34 of the metal ring 3 to improve rigidity, and deformation of the cage due to the pressure of the fluid to be sealed is suppressed. Therefore, the deformation of the main seal lip portion 22 is reduced, and the contact state between the shaft and the main seal lip portion 22 is stabilized. Accordingly, the sealing performance is improved.
[0032]
【The invention's effect】
According to the first invention, when the eccentricity occurs between the two members assembled concentrically, the radial movement of the support ring is restricted by the reinforcing ring, so that the seal lip and the support ring move relative to each other. Even if possible, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved. Further, it is possible to prevent the seal lip from being damaged due to the biting of the support ring into the seal lip.
[0033]
According to the second invention, the support ring and the reinforcement ring are fitted and the radial movement of the support ring is restricted, so that when an eccentricity occurs between two concentrically assembled members, Even if the lip and the support ring are relatively movable, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved. Further, it is possible to prevent the seal lip from being damaged due to the biting of the support ring into the reel lip.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an oil seal according to a first embodiment of the present invention.
FIG. 2 is a half sectional view showing the structure of an oil seal according to a second embodiment of the present invention.
FIG. 3 is a half sectional view showing a configuration of an oil seal according to the prior art.
FIG. 4 is a diagram for explaining a problem of an oil seal according to the prior art.

Claims

A sealing device that seals between a housing and a shaft that is concentrically assembled. The sealing device includes a reinforcing ring that is assembled to the housing, and the reinforcing ring includes a cylindrical portion that is assembled to the housing, and a reaction portion of the cylindrical portion. A flange portion extending in the inner diameter direction from the end portion on the fluid target side to be sealed, and a support ring support portion extending from the inner diameter end portion of the flange portion to the target fluid side to be sealed are provided. A seal lip made of a rubber-like elastic body provided integrally with the reinforcing ring and in sealing contact with the shaft; A cylinder portion extending toward the fluid to be sealed on the side opposite to the fluid to be sealed of the seal lip, and extending from the end on the fluid to be sealed side of the tube to the inner diameter side at right angles to the axis. The seal is mounted on the support ring support portion so as to be relatively movable between the support ring support portion and an inward flange portion having a gap. A support ring that supports the lip; The inner diameter side end provided in the support ring is formed on the inner diameter side of the anti-sealing target fluid side edge of the seal lip, The cylindrical portion of the support ring is engaged with the inner diameter portion of the reinforcing ring to restrict radial movement, and deformation of the support ring due to deformation of the seal lip due to the pressure of the fluid to be sealed is suppressed. A sealing device characterized by that.