CN210118456U - Framework oil seal - Google Patents

Abstract

The utility model relates to a skeleton oil blanket. The framework oil seal is generally annular and comprises a main body part, a reinforcing framework and a pressing device. The main body portion has a seal lip on a radially inner side adapted to mate with a shaft to be sealed. The pressing device is suitable for pressing the sealing lip on the shaft to be sealed. The seal lip includes a tapered portion whose axial dimension gradually decreases in a direction from a radially inner side toward a radially outer side. According to the utility model discloses, even also can guarantee under the condition that the seal lip is along with using wearing and tearing that sealed effect is stable to the life-span of skeleton oil blanket has been improved.

Description

Framework oil seal

Technical Field

The utility model relates to a sealing member field, more specifically relates to a skeleton oil blanket.

Background

In a working machine such as a wheel loader, a rotary shaft such as a drive shaft or half shaft, a crankshaft, a propeller shaft or the like is supported in a housing of an axle, an engine, a transmission or the like via bearings, in particular tapered roller bearings. Generally, components such as bearings are lubricated with lubricating oil. In order to prevent the leakage of the lubricating oil, an oil seal structure needs to be provided near the end of the rotating shaft.

The framework oil seal is an oil seal structure widely adopted at present. As shown in fig. 5, the skeleton oil seal, which is annular in general, generally includes a main body portion 1 'made of a rubber material, a reinforcing skeleton 2' made of a metal material (e.g., steel), and a coil spring 3 'serving as a pressing means, wherein the coil spring 3' under tension presses a seal lip 4 'formed on a radially inner side of the main body portion 1' against a rotating shaft (not shown) to be sealed.

The sealing lip 4' of the existing framework oil seal is in a sharp-angled style. At the beginning of use, the contact area between the seal lip 4 'and the rotating shaft is small, while the amount of tension of the coil spring 3' is large and accordingly a large pressing force is applied to the seal lip 4 ', and therefore the specific pressure per unit area is large, resulting in a rapid wear of the seal lip 4'. On the other hand, as the seal lip 4 'is used and worn, the contact area between the seal lip 4' and the rotating shaft increases, while the amount of tension of the coil spring 3 'decreases and accordingly the pressing force applied to the seal lip 4' decreases, so that the specific pressure per unit area decreases, resulting in deterioration of the sealing effect, affecting the service life of the skeleton oil seal.

SUMMERY OF THE UTILITY MODEL

In view of the above problems in the prior art, an object of the present invention is to provide a skeleton oil seal capable of maintaining a stable sealing effect.

In order to achieve the above object, the utility model provides a skeleton oil blanket, the skeleton oil blanket is cyclic annular as a whole to including main part, reinforcing skeleton and closing device, the main part has in radial inboard be suitable for with treat sealed axle complex sealing lip, closing device be suitable for with sealing lip compresses tightly epaxial treating sealed, sealing lip includes that axial dimension reduces gradually along the direction from radial inboard outside.

Preferably, the framework oil seal of the present invention may have one or more of the following advantageous technical features:

-the radially inner surface of the conical portion is a convex surface adapted to be in interference fit with a shaft to be sealed;

-the sealing lip further comprises a second conical portion located radially outside and adjacent to the conical portion, the axial dimension of the second conical portion increasing in a direction from the radially inside towards the radially outside;

-the body portion is formed with an annular groove at a position corresponding to the sealing lip, the pressing means being disposed in the annular groove;

-the hold-down device is a helical spring;

-the main body portion is U-shaped in cross-section, the sealing lip being formed at an axially open end of the U-shape;

-the reinforcing cage is L-shaped in cross-section.

-the main body portion is made of a rubber material and the reinforcing skeleton is made of a metal material or an engineering plastic;

-the reinforcing cage is encased within the body portion;

the main body portion is also formed, radially on the inside, with a dust lip which is axially spaced apart from the sealing lip.

The utility model provides a frame oil blanket's seal lip includes that axial dimension reduces gradually along the direction from radial inboard to the radial outside. In an initial stage of use, a contact area between the seal lip and a shaft to be sealed is large, and a specific pressure per unit area is small as compared with an existing seal lip in a sharp-angled shape, thereby slowing down early wear of the seal lip. On the other hand, when the seal lip wears with use, although the pressing force applied to the seal lip by the pressing device decreases, the contact area between the seal lip and the shaft to be sealed decreases, and therefore the specific pressure per unit area can be kept substantially constant, so that a stable sealing effect can be maintained.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings:

fig. 1 is a perspective view of a skeleton oil seal according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the backbone oil seal shown in FIG. 1 taken along a plane containing the central axis;

FIG. 3 is an enlarged partial view of the backbone oil seal shown in FIG. 2;

FIG. 4 is a further enlarged view of the backbone oil seal shown in FIG. 3, showing the seal lip;

fig. 5 is a schematic structural view of a skeleton oil seal shown in correspondence with fig. 3.

Detailed Description

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. The described embodiments are not intended to limit the present invention, but are merely exemplary, and not all the features or combinations thereof described in the embodiments are essential to the present invention.

Fig. 1 and 2 show a framework oil seal according to an embodiment of the present invention. Fig. 3 and 4 show the structure of the framework oil seal, particularly the structure of the seal lip, in an enlarged view.

As shown in fig. 1 to 3, the skeleton oil seal according to the present embodiment is generally annular, and includes a main body portion 1, a reinforcing skeleton 2, and a pressing device 3. A seal lip 4 and a dust lip 5 are formed radially inside the body 1.

In the present embodiment, the main body portion 1 has a substantially U-shaped cross section. More specifically, the body portion 1 includes an outer circumferential wall and an inner circumferential wall that are substantially parallel to each other, and a bottom wall that connects the outer circumferential wall and the inner circumferential wall together at one axial end. The outer peripheral wall, the inner peripheral wall, and the bottom wall are integrally formed, and define a space in which lubricating oil can be stored. It will be appreciated that the body portion 1 need not be U-shaped in cross-section, but other shapes of cross-section are possible. The body portion 1 may be made of a rubber material.

The reinforcing frame 2 supports and reinforces the main body 1. In the present embodiment, the reinforcing cage 2 is housed within the main body portion 1, and has an L-shaped cross section, i.e., housed within the outer peripheral wall and the bottom wall of the main body portion 1. In other embodiments, the reinforcing cage 2 may be attached to the surface of the main body 1 instead of being housed in the main body 1. The reinforcing cage 2 may be made of a metal material, such as steel, or may be made of an engineering plastic having a light weight and sufficient strength.

The pressing device 3 serves to press the sealing lip 4 against a shaft to be sealed, which is not shown in the drawing. In the present embodiment, the pressing device 3 is a coil spring having a circular cross section. In order to arrange the coil spring, the main body 1 is formed with an annular groove in which the coil spring is disposed at a position corresponding to the seal lip 4. In other embodiments, the compression means 3 may be a serpentine coil spring, and accordingly, the annular groove formed in the body portion 1 has a rectangular cross-section. Other pressing means than a coil spring may be used as long as a pressing force that presses the seal lip 4 against the shaft to be sealed can be applied.

The sealing lip 4 and the dust lip 5 are spaced apart in the axial direction. In the present embodiment, the sealing lip 4 is formed at the axial opening end of the main body 1, and the dust-proof lip 5 is formed at the other end of the main body 1, i.e., the end where the bottom wall is located. The sealing lip 4 and the dust lip 5 are both tightly fitted to the shaft to be sealed. The seal lip 4 is for preventing leakage of seal oil, and the dust lip 5 is for preventing intrusion of foreign matters such as dust.

Fig. 4 shows a specific structure of the seal lip 4. The seal lip 4 includes a tapered portion 41 whose axial dimension gradually decreases in a direction from the radially inner side toward the radially outer side. The radially inner surface of the conical portion 41 is convex adapted for an interference fit with the shaft to be sealed. The sealing lip 4 further comprises a second conical portion 42 located radially outside and adjacent to the conical portion 41. The axial dimension of the second tapered portion 42 gradually increases in the direction from the radially inner side toward the radially outer side. In other words, the axial dimension of the sealing lip 4 is smallest at the transition between the tapered portion 41 and the second tapered portion 42.

INDUSTRIAL APPLICABILITY

The framework oil seal of the utility model can be applied to any occasion that needs to prevent the leakage of lubricating oil, including but not limited to being used on the axle of engineering machinery such as wheel loader or on parts such as engine, derailleur, motor.

The utility model discloses a skeleton oil blanket is when using, at first installs the skeleton oil blanket at treating sealed epaxial. By designing the radially inner side surface of the tapered portion 41 as a convex surface adapted to be in interference fit with the shaft to be sealed, the main body portion 1 of the skeleton oil seal is prevented from being in friction fit with the shaft by the maximum axial dimension of the tapered portion 41 during the mounting process, facilitating the mounting work to some extent.

When just using after the installation, the utility model discloses a skeleton oil blanket is similar with the effect of current skeleton oil blanket. However, after a short period of use, the contact area of the sealing lip 4 with the shaft is maximized, and the contact pressure of the pressure device 3 is also close to the maximum. As the use progresses, the seal lip 4 wears, the pressing force applied to the seal lip 4 by the pressing device 3 decreases, but the contact area between the seal lip 4 and the shaft also decreases, so that the specific pressure per unit area on the seal lip 4 can be kept substantially constant, thereby enabling a stable sealing effect to be maintained.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments disclosed above without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples disclosed herein be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.

Claims (10)

1. A skeleton oil seal, which is generally ring-shaped and comprises a main body portion (1), a reinforcing skeleton (2), and a pressing device (3), the main body portion (1) having, on the radially inner side, a seal lip (4) adapted to be fitted to a shaft to be sealed, the pressing device (3) being adapted to press the seal lip (4) against the shaft to be sealed, characterized in that the seal lip (4) comprises a tapered portion (41) whose axial dimension gradually decreases in a direction from the radially inner side toward the radially outer side.

2. The backbone oil seal of claim 1, wherein the radially inner surface of the tapered portion (41) is convex adapted for interference fit with a shaft to be sealed.

3. The framework oil seal according to claim 1, wherein the seal lip (4) further comprises a second tapered portion (42) located radially outside and adjacent to the tapered portion (41), and an axial dimension of the second tapered portion (42) gradually increases in a direction from a radially inner side toward a radially outer side.

4. The skeleton oil seal according to any one of claims 1 to 3, wherein the main body portion (1) is formed with an annular groove in a position corresponding to the seal lip (4), the pressing means (3) being disposed in the annular groove.

5. A skeleton oil seal according to any one of claims 1 to 3, characterized in that the pressing means (3) is a coil spring.

6. The backbone oil seal according to any one of claims 1 to 3, wherein the main body portion (1) has a U-shaped cross section, and the seal lip (4) is formed at an axial opening end of the U-shape.

7. The framework oil seal as claimed in claim 6, wherein the cross section of the reinforcing framework (2) is L-shaped.

8. The skeleton oil seal of any one of claims 1 to 3, wherein the main body portion (1) is made of a rubber material, and the reinforcing skeleton (2) is made of a metal material or an engineering plastic.

9. A skeleton oil seal according to any one of claims 1 to 3, characterized in that the reinforcing skeleton (2) is housed inside the main body portion (1).

10. The backbone oil seal according to any one of claims 1 to 3, wherein the main body portion (1) is further formed with a dust lip (5) on a radially inner side, the dust lip (5) being spaced apart from the seal lip (4) in an axial direction.

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