JP2003106463A - Hermetically sealed device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetically sealed device preventing the damage to a seal lip and capable of improving workability in assembling while securing a dustproof performance. SOLUTION: This hermetically sealed device 1 seals between a housing 3 and a rotary shaft 2 to be inserted in the housing 3, which are relatively rotatably assembled to each other. This hermetically sealed device is characterized by having an annular seal body 4 to be installed in the housing 3, the seal lip 51 sequentially provided in the seal body 4 and slidably and hermetically contacted with the rotary shaft 2, and a protective guide part 64 provided in the insertion side of the rotary shaft 2 relative to the seal lip 51 and protecting the seal lip 51. This device is also characterized in that the inside diameter of the protective guide part 64 is smaller than the inside diameter of the seal lip 51.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device such as an oil seal used for a shaft sealing portion of various devices such as a diff side seal for an automobile, and more particularly to a sealing device having means for protecting a seal lip.

[0002]

2. Description of the Related Art As a conventional sealing device of this type, there is, for example, one shown in FIG. That is, this sealing device 100 is used in a diff part for an automobile, and seals between a stepped spline shaft 101 as a rotary shaft and a housing 102 which is relatively rotatably assembled (FIG. 5C). reference).

The sealing device 100 is provided with an annular seal body 103 which is attached to a housing 102. The seal body 103 has a reinforcing ring 105 which is a cylindrical member having an L-shaped cross section having an inward flange 104. It has a rubber-like elastic body 106 integrally baked and fixed to the outer peripheral surface of the cylindrical portion 105A of the reinforcing ring 105 and the end surface A on the atmosphere side.

Further, the spline shaft 10 is attached to the inner end of the flange portion 104 of the reinforcing ring 105 continuously with the rubber-like elastic body 106.
1. A seal lip portion 1 slidably sealingly contacting the outer peripheral surface of 1.
It is equipped with 07.

The seal lip portion 107 is the flange portion 10.
4 has a wedge-shaped main lip 108 extending from the inner end to the axial sealed fluid side O, and a substantially rectangular shape having a tapered cross-section extending from the inner end of the flange portion 104 to the atmospheric atmosphere side A and tilting toward the radial spline shaft 101 side. It is made up of a secondary lip 109. The sub-lip 109 prevents dust from entering from the atmosphere side A.

The main lip 108 has a spring 1 for applying a tightening force to the spline shaft 101 on the outer peripheral side.
10 is installed.

In addition to the above structure, as shown in FIG. 5B, the rubber-like elastic body 106 is provided at the inner end of the flange portion 104.
There is also used a sealing device which is provided with a side lip 112 having a substantially rectangular cross-section that is tapered toward the radial direction and extends outward in the axial direction toward the atmosphere side A.

The side lip 112 slidably and sealingly contacts the end face of the step portion of the spline shaft 101 to prevent dust from entering from the atmosphere side A, and is used for so-called dust protection.

[0009]

However, when the sealing device 100 is assembled between the housing 102 and the spline shaft 101, the sealing device is mounted on the spline shaft 101 having a plurality of step portions as shown in FIG. 5 (c). When the 100 is inserted, the seal body 103 has the spline portion 101A.
The seal lip portion 1 which is provided continuously with the seal main body 103 by hooking or deforming a stepped portion (B portion in the drawing)
The tip of 07 is often scratched, which impairs the sealability and, at the same time, pays close attention to the assembly, resulting in deterioration of workability.

The present invention has been made to solve the above-mentioned problems of the prior art, and the purpose thereof is to:
It is an object of the present invention to provide a sealing device capable of preventing damage to a seal lip when inserting a spline shaft into the sealing device while ensuring the sealing property and improving workability in assembly.

[0011]

In order to achieve the above object, in the sealing device of the present invention, a sealing device for sealing between a housing assembled so as to be rotatable relative to each other and a rotary shaft inserted into the housing. A ring-shaped seal body mounted on the housing, a seal lip continuously provided on the seal body and slidably sealingly contacting the rotary shaft, and a seal lip provided on the rotary shaft insertion side with respect to the seal lip. And a protection guide portion having an inner diameter smaller than the inner diameter of the seal lip.

As a result, in the conventional sealing device,
When inserting a rotary shaft that has a spline part or a step part,
Although the spline portion or the like is likely to damage the seal lip and impair the sealing performance, in the present invention, since the inner diameter of the protection guide portion is formed to be smaller than the inner diameter of the seal lip, the rotating shaft is first Since it is inserted along the protection guide portion, it is possible to improve the workability, prevent damage to the seal lip, and provide a sealing device having excellent durability and sealing performance.

The inner diameter of the protection guide portion may be smaller than the outer diameter of the rotary shaft.

With this, since the rotary shaft can be inserted without shaking when the rotary shaft is inserted, it is possible to prevent the central shaft from being aligned or the shaft from being obliquely inserted, and the spline portion may come into contact with the seal lip and be damaged. Can be prevented and workability can be improved.

The protection guide portion may form a labyrinth seal portion having a gap between the protection guide portion and the recess provided in the rotary shaft.

As a result, not only the seal lip portion,
Since the labyrinth seal part between the protection guide part and the concave part provided on the rotary shaft also exhibits the sealing property, it is possible to provide a sealing device having improved sealing performance and excellent durability.

The shape of the tip of the protection guide portion may be rectangular or R-shaped.

As a result, the contact resistance with the protective guide portion when the rotary shaft is inserted is reduced, and the workability can be improved.

It is preferable that the protection guide portion has rigidity higher than that of the seal lip.

As a result, it is possible to prevent the protective guide portion from being deformed and the spline portion or the like of the rotary shaft directly abutting on the seal lip to prevent damage, and it is possible to provide a sealing device having excellent durability.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
Unless otherwise specified, the material, the shape, the relative arrangement, and the like are not intended to limit the scope of the present invention thereto.

The configuration of the sealing device according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a half sectional view showing a sealing device according to an embodiment of the present invention. FIG. 2 is a half sectional view showing a sealing device having a side lip according to an embodiment of the present invention. FIG. 3 is a longitudinal sectional view showing a state before inserting the spline shaft into the sealing device according to the present embodiment fitted in the housing. FIG. 4 is a detailed cross-sectional view of the sealing device sealing portion according to the present embodiment after inserting the spline shaft.

The sealing device described below seals the annular gap between the housing and the spline shaft, which are concentrically assembled with each other and are movable relative to each other.

The sealing device 1 shown in FIG. 1 has an annular seal body 4 fitted and fixed to a housing 3, and a seal body 4.
And a seal lip portion 5 which is continuously provided and slidably sealingly contacts the outer peripheral surface of the spline shaft 2, and when the spline shaft 2 is inserted into the seal body 4 fixed to the housing 3, The protective member 6 has a protective guide portion 64 provided on the insertion side for protection.

The seal body 4 comprises a reinforcing ring 8 and a rubber-like elastic body 9 integrally fixed to the reinforcing ring 8 by baking.

The reinforcing ring 8 is on the atmosphere side A, that is, the spline shaft 2.
It is a cylindrical member having a substantially U-shaped cross section having a concave portion 81 that is open on the insertion side. Further, a flange portion 82, which faces inward in the radial direction, is provided at the tip of the inner peripheral portion of the recess 81.

A rubber-like elastic body 9 is integrally baked and fixed on almost the entire inside and outside of the reinforcing ring 8.

At the inner end of the flange portion 82 of the reinforcing ring 8, a seal lip portion 5 made of a rubber-like elastic body is provided continuously with the rubber-like elastic body 9.

The seal lip portion 5 has a main lip 51 and a sub lip 52, and the main lip 51 has a flange portion 82.
From the inner end to the axially sealed fluid side O, and has a wedge-shaped cross section. A flange portion 82 is provided on the atmosphere side A of the main lip 51.
A sub-lip 52 having a substantially rectangular shape with a tapered cross section is provided, which extends from the inner end to the air side A in the axial direction and is inclined inward in the radial direction.

The main lip 51 and the sub-lip 52 are slidably and sealingly contacted with the outer peripheral surface of the spline shaft 2. The main lip 51 seals the sealing fluid, and the sub-lip 52 from the atmosphere side A. It is designed to prevent dust from entering. A spring 10 for applying a tightening force to the spline shaft 2 is provided on the outer peripheral side of the main lip 51.

On the atmosphere side A of the seal body 4, that is, on the shaft insertion side,
An annular protective member 6 having a substantially L-shaped cross section is provided.

The protective member 6 includes a protective member reinforcing ring 61 having a substantially L-shaped cross section, a cylindrical portion 62 protruding toward the sealed fluid side O and fitted in the recess 81 of the reinforcing ring 8, and the protective member 6. A cylindrical portion 62 has a flange portion 63 radially inward from an end on the atmosphere side A, and an inner peripheral side thereof is made of a resin which plays a role of preventing scratches of a guide and a seal portion when the spline shaft is inserted. The protection guide portion 64 is provided.

As the protective member 6, a member provided with a side lip 65 as shown in FIG. 2 according to the shape of the spline shaft is also used.

The inner diameter of the protection guide portion 64 is set smaller than that of the main lip 51 and the sub lip 52 (the tightening margin is large). Further, in consideration of contact resistance at the time of inserting the shaft and catching at a corner, it is preferable that the tip has an R shape or a rectangular shape. Further, by making the rigidity higher than that of the seal lip portion 5, it is possible to prevent the function of protecting the seal lip portion 5 from being deteriorated due to the deflection of the protection guide portion 64.

The fitting portion 62 of the protective member 6 has a shape substantially conforming to the shape of the outer peripheral inner wall surface of the recess 81 of the reinforcing ring 8 of the seal body 4.

The protective member 6 thus constructed is attached to the seal body 4 by fitting the fitting portion 62 into the recess 81 of the seal body 4.

The seal main body 4 provided with the protective guide portion 6 as described above has the housing 3 as shown in FIG. 3 as an example.
And the spline shaft 2 are assembled.

The spline shaft 2 has a plurality of step portions 2B, and has a spline portion 2A at the tip end in the axial direction.

First, the outer peripheral surface of the outer peripheral portion of the concave portion 81 of the reinforcing ring 8 of the seal main body 4 is fitted to the inner peripheral surface of the housing 3 so as to make sealing contact with the rubber-like elastic body 9. At this time,
The fitting portion 62 of the protection member 6 is fitted in the recess 81, and the protection member 6 is attached to the seal body 4.

The spline shaft 2 is inserted into the inner circumference of the seal body 4 in that state. At this time, the protection member 6 prevents the seal body 4 from directly contacting the spline portion 2A and the step portion 2B of the spline shaft 2. Therefore, the seal body 4 is protected and is not deformed, and the continuously provided main lip 51 and sub lip 52 do not hit the spline shaft 2, so that damage is prevented. As a result, since it is not necessary to pay close attention when inserting the shaft, it is possible to improve the workability in assembly by that much.

In addition, since the protective member 6 is provided with a protective guide portion having an inner diameter smaller than that of the main lip 51 and the auxiliary lip 52, radial interference can be absorbed when the spline shaft 2 is inserted, so that the assembly can be more easily performed. The workability is improved, and it also helps prevent the seal lip 5 from being scratched.

Further, since the inner diameter of the protection guide portion 64 is smaller than the outer diameter of the sealing device sealing portion of the rotary shaft 2, the rotary shaft 2 can be inserted without shaking when the rotary shaft 2 is inserted,
It is possible to prevent the spline portion 2A from coming into contact with the seal lip portion 5 and being damaged, as well as to prevent the splines from being aligned with each other or being inserted obliquely.

Next, details of the vicinity of the seal portion after the spline shaft 2 is inserted will be described with reference to FIG.

When the spline shaft 2 is attached to the sealing device 1, if the seal portion on the side of the spline shaft 2 is flat, the protection guide portion cannot be retracted, but the spline shaft 2 remains in contact with the spline shaft 2 and continues to rub, which causes friction. This can cause problems such as wear and increased torque.

Therefore, it is preferable that the concave portion 2c is provided as shown in FIG. 4, and the protection guide portion 64 is not in contact with the spline shaft 2 when the sealing device is attached. This makes it possible to prevent frictional wear and torque increase.

Further, the labyrinth effect of the minute gap 2d between the protection guide portion 64 and the concave portion 2c can prevent dust from entering from the atmosphere side A. That is, it constitutes a sealing means for dust and dust resistance from the atmosphere side A is secured.

Incidentally, the protection member 6 shown in the above embodiment.
May be formed integrally with the seal body 4 instead of being a separate body, and the shape is not limited to the above, and the protective guide portion 64 having an inner diameter smaller than that of the seal lip portion 5 is provided on the atmosphere side A. If it is good.

Further, the protection member 6 is provided with the protection guide portion 64, but the shape thereof is not limited to the above-mentioned shape, and the point is that it has a shape capable of absorbing interference when the spline shaft 2 is inserted. good.

[0049]

As described above, according to the present invention, the protective guide portion having an inner diameter smaller than the inner diameter of the seal lip portion is provided on the shaft insertion side in order to protect the seal lip. Since the seal lip is protected and is not deformed and the seal lip does not hit the shaft, scratches can be prevented. As a result, since it is not necessary to pay close attention when inserting the shaft, it is possible to improve the workability in assembly by that much.

Further, it is possible to prevent dust from entering from the atmosphere side due to the labyrinth effect of the predetermined gap between the protective guide portion and the concave portion provided on the spline shaft. As a result, the seal resistance to the atmosphere side can be further improved.

[Brief description of drawings]

FIG. 1 is a half sectional view showing a sealing device according to an embodiment.

FIG. 2 is a half sectional view showing a sealing device having a side lip according to the present embodiment.

FIG. 3 is a vertical cross-sectional view showing a state before inserting the spline shaft into the sealing device according to the present embodiment fitted in the housing.

FIG. 4 is a detailed cross-sectional view of the sealing device sealing portion according to the present embodiment after inserting the spline shaft.

FIG. 5A is a sectional view of a conventional sealing device,
(B) is sectional drawing of the conventional sealing device which has a side lip, (c) is a figure which shows the process of inserting a spline shaft in the sealing device of (b).

[Explanation of symbols]

1 Sealing device 2 housing 3 axes 3a Spline part 3b recess 4 Seal body 4a Fitting part 4b Flange part 5 metal rings 6 seal lip 7 dust lip 8 springs 9 Inner surface 10 side lip

Claims (5)

[Claims] 1. A sealing device for sealing between a housing assembled to be rotatable relative to each other and a rotary shaft inserted into the housing, wherein an annular seal body mounted on the housing and a continuous seal body connected to the seal body. A seal lip slidably sealingly contacting the rotary shaft, and a protection guide portion provided on the rotary shaft insertion side with respect to the seal lip and having an inner diameter smaller than the inner diameter of the seal lip. A sealing device characterized by the above. 2. The sealing device according to claim 1, wherein an inner diameter of the protection guide portion is smaller than an outer diameter of the rotary shaft. 3. The sealing device according to claim 1, wherein the protection guide portion forms a labyrinth seal portion having a gap between the protection guide portion and a recess provided in the rotary shaft. 4. The sealing device according to claim 1, 2 or 3, wherein a tip of the protection guide portion has a rectangular shape or an R shape. 5. The sealing device according to claim 1, wherein the protection guide portion has rigidity higher than that of the seal lip.