JPH0557526U - Packing - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a packing having improved durability and sealability. [Structure] The packing 1 is provided in the groove 8 of the housing 7.
The packing 1 has an annular shape, and the shaft 6 is inserted into the packing 1.
The packing 1 includes a seal member 2 and a backup ring 4. The seal member 2 has an annular shape and has a lip portion 3. The backup ring 4 has an annular shape, and the seal member 2
Provided on the end face side of. The packing 1 slides the inner peripheral portion thereof on the shaft 6 to seal between the members 6 and 7. A taper portion 5 is formed on a part of the sliding surface of the backup ring 4, and the shaft 6
To form a non-contact portion with respect to. Even if the packing 1 creeps and the backup ring 4 tightens the shaft 6, the non-contact portion of the sliding surface of the backup ring 4 is not in contact with the shaft 6. The tightening force of is reduced. Therefore, packing 1
Can be prevented from rubbing with the shaft 6 and moving in the groove 8 as the shaft 6 moves.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a packing, and more particularly to a packing which is provided between two members that move relative to each other and seals the two members.

[0002]

[Prior art and its problems]

 Conventionally, as this type, there is a packing as shown in FIG. 4, and FIG. 5 shows a state in which the packing is arranged between the housing and the shaft.

The packing 31 shown in FIGS. 4 and 5 has a seal member 32 having a lip portion 33 provided with a backup ring 34, and has an annular shape as a whole, and is shown in FIG. 5, for example. By disposing between the housing 37, which is one member, and the shaft 36, which is the other member, the two members 37, 36 are sealed so that they can move relative to each other. There is.

In FIGS. 4 and 5, a housing 37, which is one member, has a shaft 36, which is the other member, inserted therein and supports the shaft 36 in a rotatable and retractable state. Further, inside the housing 37, a groove 38 is formed annularly so as to face the shaft 36, and the packing 31 is arranged in the groove 38.

The packing 31 is a so-called U-ring, in which an annular backup ring 34 is integrally provided on an annular seal member 32 having a lip portion 33, and has a U-shaped cross section. It is formed so as to form an annular shape as a whole.

The seal member 32 constituting one side of the packing 31 is made of an elastic material having excellent sealing properties and is formed into a ring shape as a whole. One end surface of the seal member 32 is located on the inner peripheral side and the outer peripheral side. An annular lip portion 33 is formed on each of and.

The backup ring 34, which constitutes the other side of the packing 31, is formed in a ring shape by using a resin material that is relatively stronger than the seal member 32 and has excellent slidability. Thus, it is provided on the end surface of the seal member 32 on the side where the lip portion 33 is not formed and is integrated.

The packing 31 is disposed in the groove 38 of the housing 37, and the shaft 36 is inserted into the inside of the packing 31, so that the outer peripheral portion of the packing 31 is inserted into the groove 38 of the housing 37. Further, the packing 31 is arranged so that the inner peripheral portion thereof abuts on the outer peripheral surface of the shaft 36, respectively.

At this time, the packing 31 is arranged such that the end surface on the side where the lip portion 33 is formed faces the one gap 41 formed between the housing 37 and the shaft 36. When the pressure P is introduced from the gap 41, the pressure P is guided to the space 39 formed between the both lip portions 33 of the packing 31.

Further, in this case, the backup ring 34 of the packing 31 has an inner peripheral portion, which is a sliding surface side with the shaft 36, of the other gap 40 formed between the housing 37 and the shaft 36. The distance between the backup ring 34 and the shaft 36 is designed to be zero or small so as to be almost closed.

By configuring the packing 31 as described above, the pressure P is introduced from the one gap 41 formed between the housing 37 and the shaft 36, and the space 39 formed by the lip portion 33 is formed. When the pressure P is introduced into the inside, the action of the pressure P causes the both lip portions 33 to expand toward the mating member side. Then, the outer lip portion 33 of the packing 31 presses the bottom surface of the groove 38 of the housing 37, and the inner lip portion 33 of the packing 31 presses the outer peripheral surface of the shaft 36. By the pressing force of both lip portions 33, a sealing property is obtained on the contact surface between each lip portion 33 and the mating members 36 and 37.

Further, even if the shaft 36 rotates or retracts, the shaft 36 slides along the inner peripheral portion of the packing 31, so that the seal between the packing 31 and the shaft 36 is reduced. Is ensured.

Further, due to the existence of the backup ring 34 of the packing 31, the pressure P introduced from the gap 41 between the housing 37 and the shaft 36 or the movement of the shaft 36 in the retracted state is caused. The seal member 32 is prevented from being deformed such that a part of the seal member 32 protrudes into the other gap 40.

However, in such a packing 31, when a creep appears such that the backup ring 34 tightens the shaft 36 due to the elastic force of the seal member 32, etc., the backup ring 34 is tightened to the shaft 36. Due to the force, friction may occur between the backup ring 34 and the shaft 36 when the shaft 36 operates, and heat may be generated.

As described above, when frictional heat is generated between the backup ring 34 and the shaft 36, this heat action accelerates the deterioration of the backup ring 34 and also affects the seal member 32. As a result, the life of the packing is shortened.

Further, since the mechanical strength of the backup ring 34 is relatively larger than that of the seal member 32, when the backup ring 34 tightens the shaft 36 due to creep or the like, the tightening force of the backup ring 34 is The pressing force of the lip portion 33 of the seal member 32 against the shaft 36 is significantly larger, and as a result, the back-up ring 34 sticks firmly to the shaft 36, and the backup ring 34 moves when the shaft 36 operates. In some cases, they could rotate or appear and disappear together with 36.

In such a case, particularly when the shaft 36 moves in the direction facing the pressure P (upward in FIG. 5), the backup ring 34 moves together with the seal member 32 along with the movement of the shaft 36, and the packing 31 The end surface on the side of the lip portion 33 comes into contact with the side surface 38a of the groove 38 of the housing 37.

Then, the space 39 formed by the lip portion 33 of the seal member 32 is closed by the side surface 38 a of the groove 38, and thus the pressure P is less likely to be introduced into the space 39, and accordingly, the pressure P is less likely to be introduced. In some cases, the pressing force of the lip portion 33 against the mating members 36 and 37 was insufficient, and the sealing performance became unstable.

Further, when the shaft 36 further advances from the state where the end surface of the packing 31 is in contact with the side surface 38 a of the groove 38, a part of the lip portion 33 on the inner peripheral side of the seal member 32 is deformed, and the housing is deformed. The seal member 32 may be damaged due to the protrusion to one gap 41 formed between the shaft 37 and the shaft 36.

The present invention solves the above problems, and an object thereof is to provide a packing that improves durability and stabilizes sealing performance.

[0021]

[Means for solving problems]

 In order to solve the above problems, the present invention is a packing which is provided on one member of two members that move relative to each other and slides on the other member at a sliding surface to seal between the two members. And a means for providing an annular seal member and an annular backup ring provided on the end face side of the seal member and having a non-contact portion with a mating member on a part of the sliding surface. It was adopted. Further, the non-contact portion of the backup ring is formed by a taper portion, and the non-contact portion of the backup ring is formed by an annular step portion.

[0022]

[Advantage] This invention adopts the above-mentioned means, and after the packing is provided so as to be interposed between the members, even if pressure is introduced from the gap formed between the members, the presence of the back-up ring , It is designed to prevent the seal member from being deformed by the action of pressure.

Even if the packing is creeped or the like, the backup ring does not strongly tighten the mating member.

That is, by forming a non-contact portion for the mating member on a part of the sliding surface of the backup ring, even if the backup ring tightens the mating member due to the deformation of the packing, the non-contact portion on the sliding surface is not formed. Since the mating member is not tightened at the contact area, the tightening force of the back-up ring on the mating member is reduced.

Therefore, by reducing the tightening force of the backup ring, it is possible to prevent the backup ring from sticking to the mating member, and it is possible to always position the packing in a good state even when the two members move relative to each other. It is also possible to prevent friction between the backup ring and the mating member.

[0026]

【Example】

 Embodiments of the present invention shown in the drawings will be described below. FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a usage state of the packing shown in FIG.

That is, the packing 1 shown in FIGS. 1 and 2 is provided in the groove 8 of the housing 7 which is one member, and the shaft 6 which is the other member is slid so that both members are A seal member 2 having a lip portion 3 is provided with a backup ring 4 for sealing between 7 and 6, and a taper portion 5 which is a non-contact portion with respect to the shaft 6 is provided on a sliding surface side of the backup ring 4. Is provided.

In FIGS. 1 and 2, a housing 7 which is one member has a shaft 6 which is the other member inserted therein and supports the shaft 6 in a rotatable and retractable state. An annular groove 8 is formed in the inner peripheral portion of the groove 7 so as to face the shaft 6, and the packing 1 is arranged in the groove 8.

The packing 1 is a so-called U-ring, which is composed of a seal member 2 and a backup ring 4, and has a U-shaped cross section and an annular shape as a whole. By arranging the packing 1 in the groove 8 of the housing 7 and further inserting the shaft 6 inside the packing 1, the packing 1 can slide its inner peripheral portion along the outer peripheral surface of the shaft 6. In this state, the two members 7, 6 are interposed.

The seal member 2 that constitutes one of the packings 1 is formed in an annular shape as a whole by using an elastic material having excellent sealing properties, and one end surface of the seal member 2 has an inner peripheral side and an outer peripheral side. An annular lip portion 3 is formed on each of and.

The backup ring 4 that constitutes the other side of the packing 1 is formed in a ring shape by using a resin material that is relatively stronger than the seal member 2 and has excellent slidability. The seal member 2 is provided at the end surface portion on the side where the lip portion 3 is not formed.

In this case, the backup ring 4 is formed such that the inner peripheral portion forming the sliding surface thereof substantially closes the gap 10 formed between the housing 7 and the shaft 6. The distance between the opposing surfaces of the sliding surface of the backup ring 4 and the outer peripheral surface of the shaft 6 is set to be zero or small.

Then, on the sliding surface side of the backup ring 4, a portion close to the seal member 2 is formed as a sliding surface for the shaft 6, and at the other portions, it is directed toward the end surface of the back-up ring 4. Therefore, the tapered portion 5 is formed in a ring shape in the circumferential direction so as to be separated from the outer peripheral surface of the shaft 6, and the tapered portion 5 forms a non-contact portion with respect to the shaft 6.

Next, the operation of the above will be described. As shown in FIG. 2, the packing 1 is arranged in the groove 8 of the housing 7 which is one member, so that the packing 1 is provided between the housing 7 and the shaft 6 which is the other member. As a result, the members 1 and 6 are sealed by the packing 1.

In this case, the packing 1 is arranged so that the end surface on the side where the lip portion 3 is formed faces the one gap 11 formed between the housing 7 and the shaft 6, and Thus, the pressure P introduced from the one gap 11 is guided to the space 9 formed between both lip portions 3 of the packing 1.

When the pressure P introduced from this one gap 11 is introduced into the space 9 of the packing 1, the action of this pressure P causes both lip portions 3 to move toward the mating members 7, 6 respectively. It can be expanded. Then, the lip portion 3 on the outer peripheral side of the packing 1 presses the bottom surface of the groove 8 of the housing 7, and the lip portion 3 on the inner peripheral side presses the outer peripheral surface of the shaft 6, respectively. By the pressing force of 3 against the mating members 7 and 6, a sealing property can be obtained at the contact surface between each lip portion 3 and the mating members 7 and 6.

Further, even if the shaft 6 rotates or retracts, the shaft 6 slides along the inner peripheral portion of the packing 1 to ensure the sealing property between the packing 1 and the shaft 6. It is supposed to be done.

Further, the backup ring 4 of the packing 1 is positioned in the groove 8 in such a manner that the inner peripheral portion forming the sliding surface thereof closes the other gap 10 between the housing 7 and the shaft 6. Therefore, due to the presence of the backup ring 4, a deformation such that a part of the seal member 2 protrudes into the other gap 10 due to the action of the pressure P introduced from the one gap 11 or the movement of the shaft 6 in and out. It is being blocked.

Here, even if the packing 1 is deformed such that the shaft 6 is tightened due to creep or the like, friction heat is generated between the backup ring 4 and the shaft 6 when the shaft 6 operates. It can be reduced.

That is, a taper portion 5 is formed on the inner peripheral portion of the backup ring 4 on the sliding surface side, and the taper portion 5 forms a non-contact portion with the shaft 6 of the backup ring 4. Therefore, at the non-contact portion of the backup ring 4, the shaft 6 is not strongly tightened even if creep or the like occurs.

Further, by forming a non-contact portion on the sliding surface of the backup ring 4, the contact area with the shaft 6 can be made smaller than that of the conventional one. The reduction in the force acts to suppress friction between the back-up ring 4 and the shaft 6 when the shaft 6 operates.

Further, by reducing the tightening force of the backup ring 4 with respect to the shaft 6 as described above, it is possible to prevent the backup ring 4 from sticking to the shaft 6. Therefore, when the shaft 6 operates, the backup ring 4 Can be prevented from moving together with the seal member 2 in the groove 8 of the housing 7 together with the shaft 6.

This prevents the end surface of the packing 1 on the side where the lip portion 3 is not formed from coming into contact with the side surface 8 a of the groove 8 even when the shaft 6 is retracted and retracted. The pressure P is always preferably introduced into the void 9 to be formed. Therefore, the pressing force of the lip parts 3 against the mating members 7 and 6 can be maintained well, whereby the sealing performance can be stabilized.

Further, since the packing 1 is prevented from moving together with the shaft 6 in the groove 8 as described above, the lip portion 3 on the inner peripheral side of the packing 1 is moved to the housing 7 as the shaft 6 moves. It does not protrude into one of the gaps 11 formed between the shaft 6 and the shaft 6, and this prevents damage to the lip portion 3.

Next, a modification of the above embodiment is shown in FIG. That is, the packing 21 shown in FIG. 3 has a stepped portion 25 formed in a groove-like annular shape at the center of the inner peripheral portion on the sliding surface side of the backup ring 24, so that Since the non-contact portion with respect to is formed and the other structure is the same as that of the above-mentioned embodiment, the detailed description will be omitted by attaching the same reference numerals.

As described above, the shape of the non-contact portion formed on the sliding surface of the backup ring 4 need not be limited.

Although the packings 1 and 21 are formed in a so-called U-ring shape in the above-described embodiment and its modified example, an O-ring shape can be applied and the shape of the packing is not limited.

Further, in the above embodiment, the inner peripheral portion of the packing is the sliding surface with the mating member, but the outer peripheral portion may be the sliding surface. In this case, an annular groove that opens to the outer peripheral surface is formed on the shaft that is the other member, and the packing is arranged in this groove so that the outer peripheral surface of the packing is the one member when the shaft operates. Slide it on the inner surface of the housing so that the packing and shaft move together.

At this time, the backup ring is formed such that the outer peripheral portion that forms the sliding surface thereof has a size that substantially closes the gap formed between the housing and the shaft. The distance between the surface facing the inner surface of the housing should be zero or small.

Then, by forming a tapered portion or a stepped portion on the outer peripheral surface which is the sliding surface of the backup ring, a non-contact portion is formed with respect to the inner peripheral surface of the housing which is the counterpart member, and the shaft is formed. It is possible to prevent friction between the backup ring and the housing due to the operation of.

[0051]

[Effect of the device]

 As described above, according to the present invention, since the non-contact portion with respect to the mating member is formed on a part of the sliding surface of the backup ring, even if the packing undergoes deformation such as creep, The tightening force can be reduced compared to the conventional one.

Therefore, even if a relative movement occurs between the two members, it is possible to prevent the packing from moving in the groove, which makes it possible to stabilize the sealing performance of the packing and also to improve the packing performance. Damage can also be prevented.

Further, since the friction on the sliding surface of the backup ring can be reduced as the tightening force of the backup ring against the counterpart member is reduced, the temperature rise due to friction heat can be reduced. Therefore, there is an effect that the deterioration of the backup ring and the seal member can be suppressed and the durability can be improved.

[Submission date] April 1, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

[0021]

[Means for solving problems]

 In order to solve the above problems, the present invention is an annular packing that is mounted in an annular groove formed in one of two members that move relative to each other and slides with the other member. A seal member made of a rubber-like elastic material having a pressure receiving surface on one of the two end faces in the axial direction of the annular shape and an annular step on the surface facing the other member on the opposite end face side, and this seal. A backup ring made of a harder material than the seal member, which is provided on the stepped portion of the member and has a non-contact surface for the other member formed at the end surface side opposite to the seal member or in the middle of the contact surface with the other member, It is the one that adopts the means of having. As a second invention including the first invention, a means is adopted in which the non-contact surface of the backup ring is formed by a tapered portion having a width larger than the width of the contact surface. In addition, as a third invention including the first invention, a means is adopted in which the non-contact surface of the backup ring is formed by an annular groove portion having a width larger than the width of the contact surface.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

That is, by forming a non-contact surface for a mating member on a part of the sliding surface of the backup ring, even if the backup ring tightens the mating member due to deformation of the packing, the non-contact surface on the sliding surface is not. Since the mating member is not tightened at the contact surface, the tightening force of the back-up ring on the mating member is reduced.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

That is, the packing 1 shown in FIGS. 1 and 2 is provided in the groove 8 of the housing 7 which is one member, and the shaft 6 which is the other member is slid so that both members are A seal member 2 having a lip portion 3 is provided for sealing between 7 and 6, and a backup ring 4 is provided. On the sliding surface side of the backup ring 4, a taper portion 5 which is a non-contact surface with respect to the shaft 6 is provided. Is provided.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

The seal member 2 that constitutes one of the packings 1 is formed in an annular shape as a whole by using an elastic material having excellent sealing properties, and one end surface of the seal member 2 has an inner peripheral side and an outer peripheral side. An annular lip portion 3 is formed on each of and. Then, in this packing 1, the end surface on the side where the lip portion 3 is formed serves as a pressure receiving surface for the pressure P described later.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

The backup ring 4 that constitutes the other side of the packing 1 is formed in a ring shape by using a resin material that is relatively stronger than the seal member 2 and has excellent slidability. Then, it is mounted on an annular step formed on the inner peripheral edge of the end surface of the seal member 2 on the side where the lip portion 3 is not formed.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0033

[Correction method] Change

[Correction content]

On the sliding surface side of the backup ring 4, a portion close to the seal member 2 is formed as a sliding surface for the shaft 6, and at other portions, as it goes toward the end surface of the back-up ring 4. A taper portion 5 which is separated from the outer peripheral surface of the shaft 6 is formed in an annular shape in the circumferential direction, and the taper portion 5 forms a non-contact surface of the backup ring 4 with respect to the shaft 6.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Item name to be corrected] 0040

[Correction method] Change

[Correction content]

That is, a taper portion 5 is formed on the inner peripheral portion of the backup ring 4 on the sliding surface side, and the taper portion 5 forms a non-contact surface with the shaft 6 of the backup ring 4. Therefore, at the portion of the non-contact surface of the backup ring 4, the shaft 6 is not strongly tightened even if creep or the like occurs.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

Further, since the backup ring 4 has a non-contact surface for the shaft 6 on its sliding surface, the contact area with the shaft 6 can be made smaller than that of the conventional one. The friction force between the backup ring 4 and the shaft 6 during the operation of the shaft 6 is suppressed by interacting with the decrease in the tightening force of the shaft 6 on the shaft 6.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

Next, a modification of the above embodiment is shown in FIG. That is, in the packing 21 shown in FIG. 3, a step portion 25 is formed in a groove shape in an annular shape in the center of the inner peripheral portion on the sliding surface side of the backup ring 24 to form a groove portion. Since a non-contact surface with respect to the shaft which is the mating member is formed, the other structure is the same as that of the above-mentioned embodiment, and the detailed description thereof will be omitted by giving the same reference numerals.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction content]

As described above, the shape of the non-contact surface formed on the sliding surface of the backup ring 4 need not be limited.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

By forming a tapered portion or a stepped portion on the outer peripheral surface which is the sliding surface of the backup ring, a non-contact surface with the inner peripheral surface of the housing which is the mating member is formed, and It is possible to prevent friction between the backup ring and the housing due to the operation of.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0051

[Correction method] Change

[Correction content]

[0051]

[Effect of the device]

 The present invention has the following effects due to the above configuration. (1) The backup ring provided on the step portion on the end surface side opposite to the pressure receiving surface of the seal member is the middle of the contact surface with the other member or the non-contact surface corresponding to the other member on the end surface side opposite to the pressure receiving surface. Due to the formation of the seal member, when pressure is applied to the pressure receiving surface of the seal member, even if the pressure receiving side of the backup ring expands to the other member side due to the pressure, the backup ring is You can prevent it from protruding into the gap.

[Procedure Amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

(2) Since the non-contact surface of the backup ring with respect to the other member is formed by a tapered surface or an annular groove surface that is larger than the width of the contact surface, sliding resistance against the other member receives pressure. Can be held low.

[Procedure Amendment 15]

[Document name to be amended] Statement

[Name of item to be corrected] 0053

[Correction method] Change

[Correction content]

(3) When the backup ring receives pressure from the axial direction, the corners on the pressure receiving side of the backup ring come into contact with the mating member, so that the lubricating oil is retained between the seal member and the backup ring. To exert the lubrication effect, and at the same time, to try to deform so that the opposite side of the pressure receiving can become the mating member, so the sliding resistance is not increased.

[Brief description of drawings]

FIG. 1 is a view showing an example of packing according to the present invention.

FIG. 2 is a diagram showing a usage state of the packing shown in FIG.

FIG. 3 is a view showing a modified example of the packing shown in FIG.

FIG. 4 is a view showing a conventional packing.

5 is a diagram showing a usage state of the packing shown in FIG.

[Explanation of symbols]

 1, 21, 31 ………… Packing 2, 32 ………… Sealing member 3, 33 ………… Lip part 4, 24, 34 ………… Backup ring 5 ………… Tapered part 6, 36… ………… Shaft 7, 37 ………… Housing 8, 38 ………… Groove 8a, 38a ………… Side surface 9, 39 ………… Vacancy 10, 11, 40, 41 ………… Gap 25 ………… Steps

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[Procedure amendment]

[Submission date] April 1, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Item name to be amended] Scope of utility model registration request

[Correction method] Change

[Correction content]

[Scope of utility model registration request]

Claims (3)

[Scope of utility model registration request] 1. A seal provided between one member (7) of two members that move relative to each other and sliding on the other member (6) at a sliding surface to seal between the members (7) and (6). And a ring-shaped seal member (2) and a ring-shaped seal member (2) provided on the end face side of the seal member (2) and having a non-contact portion with a mating member (6) formed on a part of the sliding surface. Packing characterized by having backup rings (4) and (24). 2. The packing according to claim 1, wherein the non-contact portion of the backup ring (4) is formed by a tapered portion (5). 3. The packing according to claim 1, wherein the non-contact portion of the backup ring (24) is formed by an annular step portion (25).