JPH11280914A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of partitems and reduce a cost. SOLUTION: In a sealing device 3 formed such that a guide ring 4 and an oil seal 5 are assembled together, the surface of the guide ring 4 between an outer ring body 1 and the guide ring 4 is covered with an elastic substance 6 to form structure for ensuring sealing ability and this structure eliminates an O-ring used in a conventional type. This constitution further reduces a parts cost and labor required for assembly compared with a conventional type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a sealing device. This sealing device is used, for example, as an oil seal for a piston rod of a power steering device of an automobile.

[0002]

2. Description of the Related Art The structure of a conventional sealing device of this type is shown in FIG. In the figure, reference numeral 80 denotes a cylinder tube of the power steering device, 81 denotes a piston rod of the power steering device, and 82 denotes a sealing device.

The sealing device 82 includes a guide ring 83, an oil seal 84, and an O-ring 85. Conventionally, an O-ring 85
, And with the O-ring 85, the guide ring 8
The fitting surface of the cylinder tube 80 with the cylinder tube 80 is sealed.

[0004]

The above-described conventional sealing device 82 has three parts, and there is room for improvement in cost reduction, such as a large part cost and labor for assembling.

Accordingly, an object of the present invention is to reduce the number of components and cost in a sealing device.

[0006]

According to a first aspect of the present invention, a sealing device is provided in a radially opposed space between two inner and outer concentric rings, and is fitted to the inner peripheral surface of an outer ring. And a lip that is opposed to the outer peripheral surface of the inner ring body with a minute gap therebetween, and a lip that is held by the guide ring and forms a contact sealing portion or a non-contact sealing portion between the outer peripheral surface of the inner ring member. The guide ring has an elastic body attached to a fitting surface of the guide ring with respect to the outer ring.

The high-precision 2 sealing device of the present invention is provided in a radially opposed space between two inner and outer concentric rings.
A guide ring and an oil seal are combined, and the guide ring is connected to one end in the axial direction of the cylindrical portion, which is fitted to the inner peripheral surface of the outer ring, and is connected to the outer peripheral surface of the inner ring. An annular core opposed to the cylindrical portion through a minute gap, and an elastic body attached to the outer peripheral surface of the cylindrical portion, wherein the oil seal is fitted inside the cylindrical portion of the guide ring. And a lip that is attached to the inner peripheral side of the annular cored bar and forms a sealed portion with the outer peripheral surface of the inner annular body.

According to a third aspect of the present invention, in the first or second aspect, a lip that is in contact with an outer peripheral surface of the inner ring is attached to a surface of the guide ring facing the inner ring. ing.

As described above, in the present invention, the O-ring is omitted by attaching an elastic body having the same function as the O-ring used in the conventional example to the guide ring.
As a result, it is possible to reduce the cost of parts and the work of assembling, and it is possible to reduce the cost.

According to the third aspect of the present invention, the minute gap between the guide ring and the inner ring body can be closed by the lip of the guide ring, so that foreign matter can be reliably prevented from entering the oil seal side. become.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on an embodiment shown in FIG.

FIG. 1 is a vertical sectional side view of an upper half showing a use state of a sealing device according to an embodiment of the present invention. In the figure,
1 is a cylinder tube of the power steering device, 2 is a piston rod of the power steering device, and 3 is a sealing device. The cylinder tube 1 corresponds to the outer ring body of the claim,
Further, the piston rods 2 correspond to the inner ring bodies in the claims, respectively.

The sealing device 3 has a structure in which a guide ring 4 and an oil seal 5 are integrally combined.

The guide ring 4 is formed by processing a metal plate into a sheet metal, and has a wide outer cylindrical portion 4a and an outer cylindrical portion 4a.
It has a narrow inner cylindrical portion 4b provided concentrically with a, and an annular plate portion 4c connecting these. The outer cylindrical portion 4a of the guide ring 4 has a stepped shape such that a half region in the axial direction has a slightly smaller diameter, and an elastic body made of synthetic rubber or the like extends from the outer peripheral surface of the small diameter region to the outer surface of the annular plate portion 4c. 6 are applied. A lip 7 protruding radially inward is provided on the inner peripheral end side of the elastic body 6 attached to the annular plate portion 4c.

The oil seal 5 is composed of an annular core 8, an elastic body 9, a spring ring 10, and a backup ring 11. The annular metal core 8 is formed by processing a metal plate into a substantially inverted L-shape in cross section, and includes a cylindrical portion 8a and an annular plate portion 8 extending radially inward from one axial end of the cylindrical portion 8a.
b. The elastic body 9 is made of nitrile rubber (NB
R) or a synthetic rubber such as hydrogenated nitrile rubber (HNBR), etc., and is vulcanized and bonded (baked) from the cylindrical portion 8a of the annular cored bar 8 to the annular plate portion 8b. An extension 9a is provided on the inner peripheral side of the annular plate 8b of the annular core 8 in the elastic body 9 so as to extend in one axial direction. A lip 9b is provided. The spring ring 10 is a so-called garter spring, and is fitted on the outer periphery of the extension 9a to tighten the extension 9a radially inward. The backup ring 11 is formed of a synthetic resin such as nylon, and is formed between the inner periphery of the base of the extension 9a and the annular plate 8b of the annular core 8 in order to prevent the extension 9a from being inverted. It is fitted in the recess formed between them.

Incidentally, the oil seal 5 is held by the above-described guide ring 4 in such a manner as to be held in the axial direction. That is, the cylindrical portion 8 a of the annular core 8 of the oil seal 5 is press-fitted to the inner periphery of the large diameter region of the wide outer cylindrical portion 4 a of the guide ring 4 via the elastic body 8. At this time, the V-shaped lip 9b of the oil seal 5
Is opposed to the free end of the narrow inner cylindrical portion 4b of the guide ring 4.

In the sealing device 3 including the guide ring 4 and the oil seal 5, the wide outer cylindrical portion 4 a of the guide ring 4 is press-fitted to the inner peripheral surface of the cylinder tube 1. And the V-shaped lip 9b of the oil seal 5 are in contact with the outer peripheral surface of the piston rod 2, respectively. The narrow inner cylindrical portion 4b of the guide ring 4 and the backup ring 11 are opposed to the outer peripheral surface of the piston rod 2 via a minute gap.

The guide ring 4 is arranged inside the power steering apparatus, that is, on the side of the oil existing space to be sealed, and the oil seal 5 is arranged outside. Therefore, the oil inside the power steering device is prevented from directly touching the oil seal 5 side by the guide ring 4 itself. The small annular gap between the guide ring 4 and the piston rod 2 is closed by the lip 7 of the guide ring 4 to prevent leakage of oil and foreign matter mixed in oil from the small annular gap. It has become. However, even if some oil oozes out,
The V-shaped lip 9b of the oil seal 5 prevents leakage to the outside. In addition, since foreign matter mixed in the oil in the oil existing space does not leak to the oil seal 5 side, it is possible to prevent the foreign matter from being caught between the V-shaped lip 9b of the oil seal 5 and the piston rod 2 and to wear them. become able to.

When the piston rod 2 reciprocates in the axial direction, the V-shaped lip 9b of the oil seal 5 comes into sliding contact with the outer peripheral surface of the piston rod 2, but the backup ring 11 slides the V-shaped lip 9b. Because of the support, the bending is restricted and the reversal is prevented.

Furthermore, since the elastic body 6 of the guide ring 4 exists on the fitting surface between the guide ring 4 and the cylinder tube 1, it is possible to prevent oil from leaking from the fitting surface. In particular, in the present invention, by attaching the elastic body 6 to the guide ring 4, there is no waste compared with the case where an independent part such as a conventional O-ring is used extra, and the cost of parts and the number of assembling steps are reduced. Is possible, and the cost can be reduced accordingly.

It should be noted that the present invention is not limited to only the above-described embodiment, and various applications and modifications are conceivable.

(1) As the oil seal 5, a type in which the spring ring 3 is not used, a backup ring 1
It is possible to adopt a configuration in which 1 is not used.

(2) The present invention includes a guide ring 4 having no lip 7.

[0024]

According to the first to third aspects of the present invention, the guide ring has a structure in which an elastic body is applied to a fitting surface of the guide ring with the outer ring body so as to secure a sealing property therewith, which is used in the conventional example. Since the O-ring is omitted, it is possible to reduce the cost of parts and the labor of assembling as compared with the conventional example, thereby achieving cost reduction.

In particular, according to the third aspect, the lip of the guide ring can close the minute gap between the guide ring and the inner ring, so that the oil leaks to the oil seal side and is mixed with the oil. Foreign matter can be reliably prevented from entering. Therefore, it is possible to prevent the foreign matter from being caught between the lip of the oil seal and the inner ring body, and thereby both are worn.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of an upper half showing a use state of a sealing device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view of an upper half showing a use state of a conventional sealing device.

[Description of Signs] 1 Cylinder tube 2 Piston rod 3 Sealing device 4 Guide ring 4a Large outer cylindrical portion 4b Narrow inner cylindrical portion 5 Oil seal 6 Elastic body of guide ring 8 Ring core metal of oil seal 9b V of oil seal Character lip

Claims (3)

[Claims] 1. A sealing device provided in a radially opposed space between two inner and outer concentric annular bodies, wherein the sealing apparatus is fitted to an inner peripheral surface of an outer annular body and has a minute gap with respect to an outer peripheral surface of the inner annular body. And an oil seal having a lip which is held by the guide ring and forms a contact sealing portion or a non-contact sealing portion between the guide ring and the outer peripheral surface of the inner ring body. A sealing device, wherein an elastic body is attached to a fitting surface to the body. 2. A sealing device provided in a radially opposed space between two inner and outer concentric rings, wherein a guide ring and an oil seal are combined, wherein the guide ring is an inner peripheral surface of an outer ring. And an annular portion connected to one end of the cylindrical portion in the axial direction and opposed to the outer peripheral surface of the inner annular member via a minute gap, and is attached to the outer peripheral surface of the cylindrical portion. An elastic body, wherein the oil seal is provided between an annular cored bar fitted inside the cylindrical portion of the guide ring and an outer peripheral surface of the inner annular portion attached to the inner peripheral side of the annular cored bar. And a lip forming a sealing portion. 3. The sealing device according to claim 1, wherein a lip that is in contact with an outer peripheral surface of the inner ring is attached to a surface of the guide ring facing the inner ring. Characteristic sealing device.