JP2002276817A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device of high quality capable of maintaining a sealing property for a long period of time. SOLUTION: The sealing device has an outer diameter being the same or less than an inner diameter dimension of an annular groove 8 and is provided with a reinforcement ring 5 at an area fitted and retained to the annular groove 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device that fits into an annular groove provided in a shaft hole of a housing.

[0002]

2. Description of the Related Art Conventionally, as this type of sealing device, for example, as shown in a schematic view of FIG. 5, water is sealed from a stern tube 102 of a ship into which a shaft 101 connecting screws is inserted. Some are used.

In such a case, a special structure is provided in which a grease box 103 is provided inside the stern tube 102, and the shaft 101 is inserted through the grease box 103 and guided to the engine side (right side in FIG. 5). Since it is difficult to install the annular oil seal as it is (the shaft needs to be divided), the split type oil seal 10 is provided in the annular groove in the gap between the stern tube and the grease box and the shaft.
5 so that the oil seal 105 can be attached and replaced without removing the shaft 101.

[0004]

However, in the case of the above-mentioned prior art, the following problems have occurred.

[0005] As shown in FIG. 6, the oil seal 105 includes a seal lip 106 which is in close contact with the shaft 101,
It comprises a seal outer peripheral portion 107 fitted to the housing. A seal allowance is provided on the seal outer peripheral portion 107.

Here, depending on the mounting state of the oil seal 105 incorporated in the annular groove and a change in the temperature of the environment after the mounting, stress may be generated due to deformation of the seal outer peripheral portion 107 including interference. . Since this stress is mainly generated in the radial direction, there is a possibility that the sealing property of the seal lip 106 may be affected.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a high-quality sealing device capable of maintaining a sealing property for a long period of time. It is in.

[0008]

In order to achieve the above object, according to the present invention, in a sealing device fitted in an annular groove formed in a shaft hole of a housing, the sealing device has the same inner diameter as that of the annular groove. Alternatively, a reinforcing member is provided in a region having an outer diameter smaller than that, and fitted and held in the annular groove.

With this configuration, it is possible to eliminate the influence of the stress due to the deformation caused by the mounting state and the temperature change in the outer peripheral portion of the sealing device.
Since the stress mainly generated in the radial direction can be eliminated, good sealing performance can be maintained.

[0010] It is preferable that the reinforcing member has a cut portion having a predetermined gap in at least one position in a circumferential direction.

With such a configuration, when a flange or the like is attached to the end of the shaft, when a seal can be inserted, etc., the device configuration is complicated,
Even in the case where it is not possible to insert the shaft from the shaft end (by removing the shaft) due to the structure of the equipment, the seal can be easily attached or replaced.

[0012] It is also preferable that the annular groove is provided with a side wall whose width increases toward the groove bottom.

[0013] It is also suitable to be used for a stern tube of a ship.

[0014]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, and relative arrangement thereof should be appropriately changed depending on the configuration of the apparatus to which the invention is applied and various conditions, and are not intended to limit the scope of the invention to the following embodiments.

FIG. 1 is a view for explaining the configuration of an oil seal 1 as a sealing device according to an embodiment of the present invention, and FIG. 2 is a view for explaining a state in which the oil seal 1 is attached to an annular groove 8. The oil seal 1 is fitted into an annular groove 8 provided in a shaft hole of the housing 7, and seals an annular gap between the shaft hole of the housing 7 and a sliding surface of the shaft member 9.

The oil seal 1 has an annular shape, and has a fitting portion 3 fitted in an annular groove 8 provided in a shaft hole of a housing 7, a seal lip 4 in close contact with a shaft member 9, and
The rubber-like elastic body 2 includes a connection portion 2c having a substantially V-shaped cross section for connecting the fitting portion 3 and the seal lip 4.

As a characteristic configuration of the present embodiment, the oil seal 1 has an outer diameter equal to or less than the inner diameter of the annular groove 8. That is, no interference is provided on the outer periphery of the oil seal 1 as in the related art. Further, a reinforcing ring 5 is provided at the fitting portion 3 of the rubber-like elastic body 2 as a reinforcing member. here,
The reinforcing ring 5 is a rubber-like elastic body 2 held in an annular groove 8.
Are formed integrally in the region of

Further, it is preferable that the seal body is cut at least at one place in the circumferential direction and then assembled. In this case, a reinforcing ring as shown in FIG. 5 is provided with a cutting portion 5a.

In this embodiment, the oil seal 1
Is the sliding area 2a of the seal lip 4 abutting on the shaft member 9.
Is made of a material having excellent wear resistance, and at least a part of the area other than the sliding area 2a is made of a material having excellent eccentricity followability.

Further, in a state where the seal body is cut at one place in the circumferential direction and then assembled, the seal lip 4
Is applied with tension by the spring 6.

In the annular groove 8, the side wall 7a of the housing 7 is directed toward the groove bottom (outer diameter direction) in order to securely hold the oil seal 1 in the annular groove 8, as shown in FIG. A widening slope is formed, and on one side of the side wall 7a, a holding portion 7b along which a connection portion 2c having a substantially V-shaped cross section is substantially provided at the time of operation is provided. In addition, such an annular groove 8 is generally called a dovetail groove shape.

Here, as a material applied to the oil seal 1, in consideration of durability, abrasion resistance and salt water corrosion,
FKM (fluoro rubber), NBR (nitrile rubber) or H-NBR (hydrogenated nitrile rubber) is suitable for the rubber-like elastic body 2, SUS304H or SUS316 is suitable for the reinforcing ring 5, and the spring 6 is suitable for the spring 6. SU
S316 or Hastelloy C is preferred.

The oil seal 1 configured as described above is
The connection portion 2c which is bent to have a substantially V-shaped cross section provides high followability to the shaft eccentricity, and furthermore, the connection portion 2c is arranged along the holding portion 7a during operation, so that high pressure resistance is obtained. Since it can be assembled after cutting at least one place, the flange is attached to the end of the shaft, the seal can be inserted, etc., but the device configuration is complicated, or the structure of machinery and equipment Above, even when it is not possible to insert the shaft from the shaft end (by pulling out the shaft), the seal can be easily attached and exchanged. In particular, the stern tube of a ship as shown in FIG. It is suitable when applied to.

In the present embodiment, since no interference is provided on the outer periphery of the oil seal 1, the influence of the stress caused by the deformation caused by the mounting state or the temperature change is not provided on the outer periphery of the oil seal 1. Since it is possible to eliminate the stress that occurs mainly in the radial direction, it is possible to maintain good sealing performance.

However, since the side wall 7a is a slope that widens in the groove bottom direction (outer diameter direction), in the region of the oil seal 1 located near the side wall 7a, the side wall 7a is deformed along the slope. A stress A (indicated by an arrow in FIG. 2) is generated. Conventionally, a margin is provided on the outer periphery, so that there is no deformation due to the stress A due to the balance with the stress generated by the interference, but in the present embodiment, no margin is provided on the outer periphery. Therefore, the annular groove 8 is deformed in the outer diameter direction due to the stress A.
There is a possibility that the fitting force (holding force by the side wall 7a) may be reduced, and if the entire oil seal 1 is deformed in the outer diameter direction, the sealing performance may be affected.

For this reason, in the present embodiment, the reinforcing ring 5 is provided on the fitting portion 3 of the rubber-like elastic body 2 as described above, and by providing the reinforcing ring 5, the fitting portion 3 is formed. The oil seal 1 can be reinforced, and the oil seal 1 can be securely held in the annular groove 8, and can be prevented from being deformed by the stress applied to the oil seal 1. The holding force by the side wall 7a can be maintained by holding the groove 8 in the groove 8. In addition, when the housing 7 and the shaft member 9 are moved relative to each other, even when a force that tries to pull out from the annular groove 8 in the inner diameter direction acts on the oil seal 1, the oil seal 1 is provided by providing the reinforcing ring 5. It can be held in the annular groove 8.

Here, in this embodiment, a hard steel wire having a substantially circular cross section is used for the reinforcing ring 5 as shown in FIG. 1A, but as shown in FIG. Spring 5b
May be used. These reinforcing rings 5 are metal members having elasticity, but may be rubber members or resin members, or may be leather members or cloth members. However, when a rubber member or a resin member is used as the reinforcing ring, it is preferable that the member has a predetermined hardness (in the case of a rubber member, JIS A: 90 or more) and has a small linear expansion rate (shrinkage rate). And when the reinforcing ring 5 is not metal,
The cutting portion 5a is not necessarily required and may be annular, and may be cut together with the rubber-like elastic body 2 when cutting the seal body.

Although the reinforcing ring 5 is formed integrally with the rubber-like elastic body 2, it may be buried inside the rubber-like elastic body 2 or provided on the surface of the rubber-like elastic body 2. It may be.

In the oil seal 1, the sliding area 2a of the seal lip 4 which comes into contact with the shaft member 9 is made of a material having excellent wear resistance. Since at least a part of the region 2b other than the region 2a is made of a material having excellent eccentricity followability,
The eccentricity followability can be improved.

The sliding area 2a of the seal lip 4 is preferably made of a material having excellent wear resistance and blister resistance. In particular, when used in a stern tube,
Materials having the property of becoming harder when exposed to seawater are preferred.

It is preferable that at least a part of the area other than the sliding area 2a of the seal lip 4 is made of a material having excellent eccentricity followability (several), and particularly, it is used for a stern tube. In such a case, a material having a property of not hardening even when exposed to seawater is preferable. When FKM is used, deterioration (particularly hardening) can be prevented by the heat resistance of fluorine.

Here, it is preferable to form a two-layer structure using materials having different characteristics from the FKM, but it is also preferable to apply NBR. However, in the case of a two-layer structure of NBR and FKM, NBR and FKM are different because the polymers are different.
Since a bridging structure cannot be formed at the joint portion with the KM and the strength is weakened, a two-layer structure between FKMs or NBRs may be used.

The sliding area 2a made of a material having excellent wear resistance may be limited to the area near the seal lip 4 as shown in FIG. 1 (a). As shown, it may be up to the vicinity of the connection portion 2c.

FIG. 4 is a view showing an oil seal 10 in which a fitting portion fitted into the annular groove 8 is formed as a resin member.

As shown in FIG. 4, the fitting portion 3a serving as a reinforcing member is made of PTFE (polytetrafluoroethylene), and a region 2 which is a seal body other than the fitting portion 3a.
It is also preferable to configure d as FKM. here,
As shown in the figure, the fitting portion 3a and the region 2d are integrally formed by providing an uneven fitting portion respectively.

Accordingly, the weight of the oil seal 10 can be reduced, so that the oil seal 10 can be easily handled and the assembling workability can be improved in addition to the effects described above. .

In the present embodiment, the cut surface will not be described in detail, but may be constituted by a surface perpendicular to the circumferential direction (straight cut), but may be formed by an inclined surface (bias cut). Or, for example, wavy,
Positioning can be performed by using a non-linear shape such as a mountain shape, a trapezoidal shape, a step shape, or the like, and high sealing performance can be maintained without generating a displacement of the tip of the seal lip.

Further, in the present embodiment, the cut portion of the seal body is one, but the present invention is not limited to this, and it is also suitable for cutting at a plurality of positions.

[0039]

As described above, according to the present invention,
In the outer peripheral portion of the sealing device, it is possible to eliminate the influence of stress due to deformation caused by the mounting state or temperature change, that is, it is possible to eliminate stress generated mainly in the radial direction, so that it is possible to maintain good sealing performance. Become.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a sealing device according to an embodiment of the present invention, wherein (a) is a schematic sectional view and (b) is a schematic plan view.

FIG. 2 is an explanatory view showing a state in which the sealing device according to the embodiment of the present invention is attached to an annular groove.

FIG. 3 is an explanatory diagram of an example of a sealing device according to the embodiment of the present invention.

4A and 4B are explanatory diagrams of an example of a sealing device according to an embodiment of the present invention, wherein FIG. 4A is a schematic sectional view, and FIG. 4B is a schematic plan view.

FIG. 5 is a schematic diagram illustrating a situation in which a sealing device is used in a stern tube of a ship.

FIG. 6 is an explanatory view of a conventional sealing device.

[Explanation of symbols]

1, 10 Oil seal 2 Rubber-like elastic body 2a Sliding area 2b At least part of area other than sliding area 2a 2c Connection area 2d Area that is seal body other than fitting area 3a 3, 3a Fitting area 4 Seal lip 5 Reinforcement ring 5a Cutting section 5b Leaf spring 6 Spring 7 Housing 7a Side wall 7b Holding section 8 Annular groove 9 Shaft member

Claims (4)

[Claims] 1. A sealing device fitted in an annular groove formed in a shaft hole of a housing, wherein the sealing device has an outer diameter equal to or less than an inner diameter of the annular groove, and is fitted and held in the annular groove. A sealing device comprising a reinforcing member in an area to be sealed. 2. The sealing device according to claim 1, wherein the reinforcing member includes a cut portion having a predetermined gap at least at one position in a circumferential direction. 3. The sealing device according to claim 1, wherein the annular groove is provided with a side wall whose width increases toward the groove bottom. 4. The sealing device according to claim 1, wherein the sealing device is used for a stern tube of a ship.