JPH10246187A - Oil seal structure of pump bearing - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In an oil seal structure of a pump bearing part,
Reduce the number of parts while securing the oil seal function,
Reduce the size and cost of the pump. An oil seal (7) is provided between a pump housing (2) and a pump drive shaft (4) of a pump bearing portion (3), adjacent to a bearing (6) of the pump drive shaft (4) and closer to the pump chamber (8) than the bearing (6).
In the oil seal structure of the pump bearing portion 3 in which the oil seal 7 is interposed, the oil seal 7 is disposed on the end face of the oil seal 7 on the bearing 6 side in the circumferential direction so as to be located on the extension of the pump axial portion 7d of the reinforcing ring 7c of the oil seal 7. The oil seal structure of the pump bearing unit 3 is characterized in that the projections 7e are formed continuously or at appropriate intervals in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal structure for a pump bearing used mainly in a hydraulic pump, and more particularly to a pump bearing in which the number of parts is reduced to reduce the size and cost of the pump. Related to an oil seal structure.

[0002]

2. Description of the Related Art As shown in FIG. 3, an oil seal structure of a pump bearing portion of a conventional hydraulic pump such as a vane pump has an inner wall large diameter portion 02a in a pump bearing portion 03 of a housing 02 of a vane pump 01 and a pump. Small diameter part of drive shaft 04
A bearing 06 is interposed between the bearing 06 and the inner diameter of the inner wall surface 02b of the housing 02 and the large diameter portion 04b of the pump drive shaft 04, adjacent to the bearing 06 and closer to the pump chamber 08 than the bearing 06. Between them, an oil seal 07 is interposed.

The outer surface of the bearing 06 in the axial direction of the pump is restricted by a circlip 012 fitted in an annular groove formed in the large-diameter portion 02a of the inner wall surface of the housing 02. The inner surface in the direction is regulated by a step portion 02d formed by a large-diameter portion 02a of the inner wall surface of the housing 02 and a small-diameter portion 02b of the inner wall surface via a spacer 013.

The oil seal 07 has its inner end in the axial direction of the pump regulated by a stepped portion 02e formed by an inner wall small diameter portion 02b and an inner wall tapered portion 02c of a housing 02, and a pump chamber 08. When a high hydraulic pressure is received from the
While sliding on the outer peripheral surface of the large diameter portion 04b of the large diameter portion 04b, it moves outward in the axial direction of the pump, and its outer end in the axial direction of the pump comes into contact with the spacer 013 and is thereby regulated. I have.

[0005] Since the conventional one is configured as described above, even if the oil seal 07 is moved to the bearing 06 side by receiving a high hydraulic pressure from the pump chamber 08, the spacer 01 is not moved.
3 restricts the movement, so that the oil seal 07 does not interfere with the bearing 06 and is damaged, so that the sealing function is not impaired.

[0006]

However, the spacer 013 in the conventional device only fulfills the fail-safe function as described above, and is not normally required.
The length in the pump axial direction was also increased by that amount. Therefore, an object of the present invention is to eliminate the spacer 013, reduce the number of parts, and reduce the size and cost of the pump while securing the above-mentioned fail-safe function that the conventional spacer 013 has fulfilled. It is to plan.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an oil seal structure of a pump bearing which solves the above-mentioned problems.
An oil seal structure of a pump bearing portion, wherein an oil seal is interposed between the pump housing of the pump bearing portion and the pump drive shaft, adjacent to the bearing of the pump drive shaft and closer to the pump chamber than the bearing. Protrusions are formed on the bearing-side end face of the oil seal so as to be positioned on an extension of the pump axial direction portion of the reinforcing ring of the oil seal, continuously in the circumferential direction or at appropriate intervals in the circumferential direction. An oil seal structure for a pump bearing portion.

According to the first aspect of the present invention, when the oil seal receives a high hydraulic pressure from the pump chamber, the oil seal is connected to the inner wall surface of the pump housing and the pump drive shaft. While sliding on the outer peripheral surface of the oil seal, the protrusion moves outward in the axial direction of the pump, and its projection comes into contact with the bearing. Since the oil seal is located, even if the oil seal receives a reaction due to the contact, the oil seal is hardly deformed, and the oil seal main body is not damaged, so that the sealing function is impaired. There is nothing.

Further, since it is not necessary to use a spacer as in the prior art in order to prevent the oil seal from abutting on the bearing and interfering with the bearing and being damaged, the number of parts can be reduced and the pump can be reduced in size. And cost reduction.

Further, according to the second aspect of the present invention, even if the projection comes into contact with the bearing, both of the two portions are slightly damaged. Further, since no biasing force is generated on the oil seal body, the deformation of the oil seal is further reduced, and the sealing function is less likely to be impaired.

Further, by configuring the invention according to claim 1 or 2 as described in claim 3, it is possible to easily configure the bearing with a simple lubrication using a commercially available product.

According to the fourth aspect of the present invention, even if the protrusion comes into contact with the bearing, the bearing side of the contact portion is constituted by a seal which is a stationary member. As a result, both damages at the contact portion are further reduced, so that the sealing function of the oil seal is less likely to be impaired.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the invention described in claims 1 to 4 of the present invention shown in FIGS. 1 and 2 will be described below. In these drawings, reference numeral 1 denotes a vane pump having an oil seal structure of a pump bearing portion in the present embodiment, and an oil seal structure of the pump bearing portion 3 is, as shown, a pump bearing of a housing 2 of the vane pump 1. A bearing 6 is provided between the large diameter portion 2a of the inner wall surface of the portion 3 and the small diameter portion 4a of the pump drive shaft 4.
An oil seal 7 is interposed between the small-diameter portion 2b of the inner wall surface of the housing 2 and the large-diameter portion 4b of the pump drive shaft 4 adjacent to the bearing 6 and closer to the pump chamber 8 than the bearing 6. Is equipped.

The bearing 6 has its outer surface in the pump axial direction regulated by a circlip 12 fitted in an annular groove formed in the inner wall large diameter portion 2a of the housing 2.
The inner surface of the pump 2 in the axial direction is directly regulated by a step 2d formed by the inner wall large diameter portion 2a and the inner wall small diameter portion 2b of the housing 2.

As the bearing 6, a rolling bearing is used. In the present embodiment, a single shield type ball bearing is used, and a ball 6c is provided between the outer ring 6a and the inner ring 6b. , A shield 6d is mounted on the outer side in the pump axial direction, and a seal 6e is mounted on the inner side in the pump axial direction.

The shield 6d and the seal 6e have their outer peripheral sides fixed to the outer ring 6a, and their inner peripheral sides have the inner ring 6b.
Are attached so as to form a labyrinth along the annular V-shaped groove. In addition, shield 6d
The labyrinth on the side is more precisely formed to seal the liquid.

As shown in the figure, the seal 6e has an inner peripheral edge which is erected a small length outward in the axial direction of the pump, a central portion is perpendicular to the axial direction of the pump, and a radially outward portion in the axial direction of the pump. It is an annular disk with an irregular cross section whose outer peripheral edge is rounded inward in the pump axial direction, and a portion perpendicular to the pump axial direction at the center, As described above, the oil seal 7 is fixed to the outer ring 6a so as to substantially face a projection 7e of the oil seal 7 described later.

The oil seal 7 has a metal reinforcing ring 7c having an L-shaped cross section on a radially outer base 7a having a substantially U-shaped cross section.
Is embedded and has a lip 7b connected to the base 7a. Although these are well-known structures, the oil seal 7 further has a protrusion 7e formed on the end face on the bearing 6 side so as to protrude continuously in the circumferential direction.

The projecting portion 7e is formed so as to be located on an extension of the pump axial direction portion 7d of the L-shaped reinforcing ring 7c in cross section, and further, its tip surface 7f is orthogonal to the pump axial direction. It is formed on a flat surface. Instead of being formed continuously in the circumferential direction, a plurality of protrusions 7e may be formed at appropriate intervals in the circumferential direction. In this case, the individual cross section may be circular.

The inner end of the oil seal 7 in the axial direction of the pump is regulated by a step 2e formed by a small-diameter portion 2b of the inner wall surface of the housing 2 and a tapered portion 2c of the inner wall surface. Receiving high fluid pressure from the inner surface of the housing 2 and the pump drive shaft 4
Is moved outward in the pump axial direction while sliding on the outer peripheral surface of the large-diameter portion 4b of the large diameter portion 4b.
e comes into contact with the seal 6e of the bearing 6 and is thereby regulated. In addition, 9 is a rotor of the vane pump 1, 10 is a vane, and 11 is a cam ring.

In this embodiment, since the oil seal 7 receives a high hydraulic pressure from the pump chamber 8, the oil seal 7 moves outward in the axial direction of the pump, and its projection 7e is formed.
Abuts on the bearing 6, but since the projection 7e is located on an extension of the pump axial direction portion 7d of the L-shaped cross-section reinforcing ring 7c embedded in the oil seal 7, the oil seal 7 is Even if a reaction is caused by the contact, there is almost no deformation and the oil seal main body (except for the projection 7e) is not damaged, so that the sealing function may be impaired. Absent.

Also, the contact between the oil seal 7 and the bearing 6
In order to avoid interference, it is not necessary to use a spacer as in the related art, so that the number of parts can be reduced, and the size and cost can be reduced by shortening the length in the pump axial direction.

Further, since the front end face 7f of the projection 7e is formed on a flat surface orthogonal to the pump axis direction, even if the projection 7e comes into contact with the bearing 6, both ends of the projection 7e are damaged. Is small, and no deviating force is exerted on the oil seal body, so that the deformation of the oil seal 7 is further reduced, and the sealing function is less likely to be impaired.

Further, since the projection 7e is formed so as to project toward the seal 6e of the ball bearing 6, even if the projection 7e comes into contact with the bearing 6, the projection 7e will not 6 comes into contact with the seal 6e, which is a stationary member fixedly supported by the outer ring 6a, and does not come into contact with the inner ring 6b. As a result, both damages at the corresponding contact portions are further reduced, and the sealing function of the oil seal 7 is less likely to be impaired.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a vane pump having an oil seal structure of a pump bearing portion according to an embodiment of the present invention described in claims 1 to 4 of the present application.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a diagram showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vane pump, 2 ... Pump housing, 3 ... Pump bearing part, 4 ... Pump drive shaft, 6 ... Bearing (ball bearing),
6d: shield, 6e: seal, 7: oil seal, 7
c ... reinforcement ring, 7d ... pump axial direction part, 7e ... projection part,
7f: tip surface, 8: pump chamber, 9: rotor, 10: vane, 11: cam ring, 12: circlip.

Claims (4)

[Claims] 1. A pump bearing, comprising: a pump housing having a pump housing and a pump driving shaft;
In an oil seal structure of a pump bearing part in which an oil seal is provided closer to a pump chamber than the bearing, the oil seal is located on an end face of the oil seal on the bearing side on an extension of a portion of a reinforcing ring of the oil seal in a pump axial direction. The oil seal structure of the pump bearing portion, wherein the protrusions are formed continuously in the circumferential direction or at appropriate intervals in the circumferential direction. 2. An oil seal structure for a pump bearing according to claim 1, wherein said projection has a tip surface formed on a flat surface orthogonal to the pump axis direction. 3. The oil seal structure of a pump bearing according to claim 1, wherein the bearing is a rolling bearing. 4. The rolling member according to claim 3, wherein the projecting portion is formed so as to project toward a seal side of the rolling bearing.
The oil seal structure of the pump bearing described in the above.