JP2535396Y2 - Slewing bearing sealing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for a slewing bearing of a construction machine or the like.

[0002]

2. Description of the Related Art Slewing bearings used in construction machines such as hydraulic excavators are configured as shown in FIGS. 9 and 10, for example. That is, the slewing bearing 50 includes the inner ring 51 and
An outer ring 52 rotatable with respect to the inner ring 51;
And a ball 53 interposed between the outer ring 52 and
A gap 54 between the outer peripheral surface of the inner race 51 and the inner peripheral surface of the outer race 52 is filled with a lubricant such as grease.

[0003] The sealing device for the slewing bearing 50 in which the lubricant is sealed is provided with mounting grooves 51a, 52a on the outer peripheral surface of the inner race 51 and the outer peripheral surface of the outer race 52, respectively. A sealing material 55a that is in close contact with the other axial end surface of the outer ring 52 is fitted into the groove 51a, and a sealing material 55b that is in close contact with one axial end surface of the inner ring 51 is fitted into the mounting groove 52a on the outer ring 52 side. It is configured. Here, the seal members 55a and 55b are integrally formed, rubber members having a lip-shaped cross-section and a ring-shaped planar shape, and the mounting groove 51 is formed by an adhesive.
a, 52a.

When the load does not uniformly act on the upper revolving structure mounted thereon and acts unevenly, the one end of the outer ring 52 is lowered, while the other end is rotated, as shown in FIG. The outer ring 52 is inclined with respect to the inner ring 51 so that the portion floats, and the gap 54 between the inner peripheral surface of the outer ring 52 and the outer peripheral surface of the inner ring 51 changes.

That is, at one end of the outer ring 52,
While the gap on the upper side of the ball 53 becomes larger, the gap on the lower side becomes smaller, and at the other end of the outer ring 52,
While the upper gap of the ball 53 becomes smaller, the lower gap becomes larger.

[0006] In this case, if the change in the gap 54 is small, the leakage of the lubricant can be prevented by the sealing members 55a and 55b of the sealing device.

[0007]

However, the sealing members 55a and 55b of the sealing device are, as described above,
Since the outer ring 52 is largely inclined with respect to the inner ring 51 because the outer ring 52 is fixed to the mounting grooves 51a and 52a with an adhesive, it cannot follow the inclination.
The lubricant leaks from 4 and foreign matter or the like enters the gap 54, causing seizure on the contact surface between the inner ring 51, the outer ring 52 and the ball 53, or damage due to foreign matter biting. There was an inconvenience. Further, even at a low temperature, the followability is poor, and there is a similar disadvantage.

Further, the sealing member 55a of the sealing device,
Reference numeral 55b denotes a ring-shaped member which is integrally molded. Even if a part of the member is broken, the entire sealing members 55a and 55b must be replaced.
There is also an inconvenience that the replacement work requires a great deal of labor and time because it is fixed to 1a and 52a.

Accordingly, an object of the present invention is to provide a seal device for a slewing bearing which can follow the movement of an inner ring or an outer ring and can easily replace a seal material.

[0010]

According to the present invention, a ball is interposed between an inner ring and an outer ring, and the other is rotatably mounted on one of the inner ring and the outer ring. Of the slewing bearing, the inner ring, provided with a ring-shaped seal material that is in close contact with the outer ring, and the outer ring, provided with a ring-shaped seal material that is in close contact with the inner ring, the inner ring and the outer ring with these seal materials A sealing device for a slewing bearing, in which a lubricating oil filled in a gap between the seal members is formed by dividing each of the seal members into a plurality of arc-shaped seal pieces. Pieces are combined so that the lubricant does not leak from between the seal pieces,
The inner ring is equipped so as to be movable in the radial direction, and the seal pieces of the seal material on the outer ring side are combined so that the lubricant does not leak from between the seal pieces. The present invention provides a seal device for a slewing bearing, wherein the seal device is mounted so as to be movable.

[0011]

According to the seal device for a slewing bearing of the present invention, for example, even when the outer ring is inclined with respect to the inner ring and the gap between the outer ring and the inner ring changes, each seal piece moves following the gap. Thus, leakage of the lubricant from the gap and entry of foreign matter into the gap can be prevented.

Further, when the seal material is damaged, the seal piece at the damaged portion may be replaced, and it is not necessary to replace the entire seal material.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

1 to 8 show an embodiment of the present invention. FIG. 1 is an enlarged sectional view of a main part, FIG. 2 is a partially cutaway plan view of a slewing bearing equipped with a sealing device of the present invention, FIG. 3 is FIG.
4 is an enlarged plan view of a portion A shown in FIG. 4, FIG. 4 is an exploded perspective view showing a seal holding portion provided on the inner race, and is partially cut away. FIG. 5 is a partially enlarged front view seen from a direction B shown in FIG. FIG. 7 is an enlarged sectional view illustrating the operation of the sealing device when an excessive load is applied to the outer ring, FIG. 7 is a partially enlarged plan view illustrating the operation of the sealing device when the gap between the outer ring and the inner ring is widened, FIG. 8 is a partially enlarged plan view for explaining the operation of the sealing device when the gap between the outer ring and the inner ring is narrowed.

As shown in FIG. 1, the sealing device of this embodiment is a hydraulic shovel in which a ball 3 is interposed between an inner ring 1 fixed to a vehicle body and an outer ring 2 rotatable with respect to the inner ring 1. A ring-shaped sealing member 7a, which is in close contact with the inner peripheral surface of the outer ring 2, is provided on the inner ring 1 of the slewing bearing 4.
In addition, a ring-shaped sealing member 7b that is in close contact with the outer peripheral surface of the inner ring 1 is provided so as to be able to follow the movement of the outer ring 2, and the outer peripheral surface of the inner ring 1 and the outer ring 2 are fixed by the sealing members 7a and 7b. And a lubricant 6 such as grease filled in a gap 5 between the inner peripheral surface of the base and the inner peripheral surface.

That is, the sealing device of the present embodiment is similar to that of FIG.
As shown in FIG. 2, the seal members 7a and 7b are each formed by a plurality of arc-shaped seal pieces 70 along the circumferential direction.
a, 70b, respectively, and sealing pieces 70a, 70b of the sealing materials 7a, 7b are respectively provided in the radial direction at the upper end of the outer peripheral surface of the inner ring 1 and the lower end of the inner peripheral surface of the outer ring 2, respectively. Seal insertion grooves 8a and 8b as seal holding portions for movably holding are provided, and between the seal members 7a and 7b and the seal insertion grooves 8a and 8b, each seal piece 70a on the inner ring 1 side is provided. To the upper end side of the inner peripheral surface of the outer ring 2, and each seal piece 70 b on the outer ring 2 side
And a plurality of springs 9a and 9b as urging members for urging the inner ring 1 toward the lower end of the outer peripheral surface thereof.

Here, the arc-shaped seal pieces 70a, 70
b are rubber seal lips 71a, 71b, which are urged by the springs 9a, 9b and are in close contact with the lower end of the outer peripheral surface of the inner ring 1 and the upper end of the inner peripheral surface of the outer ring 2, and the seal lips 71a, A metal seal body 72 that supports 71b
a and 72b. The seal lips 71a and 71b are integrated with the seal bodies 72a and 72b by baking.

The seal lips 71a and 71b are shown in FIG.
As shown in FIG. 3, the adjacent sealing lips 71a, 71b and the engaging portions 73a, 7
3b. Further, the seal bodies 72a and 72b are provided with gaps 74 at appropriate intervals between the other seal bodies 72a and 72b.
a and 74b are provided.

Therefore, the sealing pieces 70a, 70b
As shown in FIGS. 7 and 8, even when the inner ring 1 and the outer ring 2 move in the radial direction, the seal lips 71a, 71b
When the gap is opened, the lubricant 6 leaks, or when the seal bodies 72a and 72b come into contact with each other, the seal piece 70
There is no danger of blocking the movement of a and 70b.

As shown in FIGS. 1 and 4, the seal insertion groove 8a covers a step 80a formed by cutting off the upper corner of the outer peripheral surface of the inner ring 1 with a cover 81a. It is formed by fixing it to the upper end surface of the unit 1 with a bolt 82a. As shown in FIG. 1, the seal insertion groove 8b also covers a stepped portion 80b formed by cutting off a lower end corner of the inner peripheral surface of the outer ring 2 with a cover 81b. It is formed by fixing to an end face with a bolt 82b.
And, on the inner end surfaces of the seal insertion grooves 8a, 8b, there are provided accommodation recesses 83a for accommodating the springs 9a, 9b, respectively.
83b are provided.

In the seal insertion grooves 8a and 8b,
As shown in FIG. 1, a part of the lubricant 6 penetrates, the lubricant 6 lubricates the seal pieces 70a, 70b and the springs 9a, 9b, and the seal insertion grooves 8a, 8b and the seal Seizure, abnormal wear, etc. do not occur between the pieces 70a, 70b and the springs 9a, 9b.

That is, as shown in FIGS. 1, 4 and 5, the step portions 80 of the seal lips 71a and 71b are formed.
a, intermittent projections 75a, 75b are provided on the surface on the 80b side,
A part of the lubricant 6 is allowed to enter the seal insertion grooves 8a and 8b from the gap 5, and the surfaces of the seal lips 71a and 71b on the cover 81a and 81b side are covered with the covers 81a and 81b. Continuous projections 76 that adhere
a and 76b are provided to prevent the lubricant 6 from leaking outside from the seal insertion grooves 8a and 8b.

Next, the operation of the sealing device will be described with reference to FIGS. 6, 7 and 8.

As shown in FIG. 6, when a load external force acts on a part of the outer ring 2 of the slewing bearing 4, the outer ring 2 is pressed downward and greatly inclined with respect to the inner ring 1 fixed to the vehicle body. The upper gap 5 of the ball 3 is wide, and the lower gap 5 is narrow.

At this time, as shown in FIGS. 6 and 7, a part of the seal piece 70a provided on the inner ring 1 side is provided with a spring 9a.
The outer ring 2 moves forward in the radial direction, moves away from each other in the circumferential direction, follows the movement of the outer ring 2, and maintains contact with the upper end of the inner peripheral surface of the outer ring 2.

The seal piece 70 provided on the outer ring 2 side
6 and 8, a part of b retreats in the radial direction against the elastic force of the spring 9b and moves close to each other in the circumferential direction to follow the movement of the outer ring 2. Then, the contact with the lower end of the outer peripheral surface of the inner ring 1 is maintained.

Accordingly, there is no possibility that the lubricant 6 in the gap 5 leaks to the outside or foreign matter enters the gap 5 from the outside, and the contact surface between the rolling surface of the inner ring 1 and the outer ring 2 and the ball 3 does not. There is no damage due to seizure or foreign matter biting.

The seal piece 70 provided on the inner ring 1 side
7, even if a part of the seal lip 71a moves away from each other in the circumferential direction as shown in FIG.
a are joined by the concave and convex engaging portions 73a, so that the lubricant 6
There is no risk of leakage.

The seal piece 70 provided on the outer ring 2 side
Even if a part of b moves so as to approach each other in the circumferential direction as shown in FIG. 8, the seal lip 71b is made of rubber and is deformed by the engaging portion 73b so as not to hinder this movement. A gap 74 is provided between the seal bodies 72b.
b, and similarly does not hinder said movement.

Contrary to the case described above, when the upper gap 5 of the ball 3 is narrow and the lower gap 5 is wide, a part of the seal piece 70a provided on the inner ring 1 side is caused by the elastic force of the spring 9a. While retreating in the radial direction against the movement of the outer ring 2 and moving so as to approach each other in the circumferential direction,
While maintaining contact with the upper end of the inner peripheral surface of the outer ring 2, the outer ring 2
A part of the seal piece 70b mounted on the side moves forward in the radial direction by the elastic force of the spring 9b and moves away from each other in the circumferential direction to follow the movement of the outer ring 2,
The contact with the lower end of the outer peripheral surface of the inner ring 1 is maintained.

Further, even if a part of the sealing members 7a, 7b is damaged, it is sufficient to replace the damaged sealing pieces 70a, 70b without having to replace the entire sealing members 7a, 7b. Is easy.

The sealing device of the present invention is not limited to the one shown in the above embodiment. In short, the seal material is divided into a plurality of arc-shaped seal pieces, and the seal pieces are equipped so as to be movable in the radial direction with respect to the inner ring and the outer ring, and can follow the movement of the inner ring and the outer ring. It is good if you do.

[0033]

As described above, the sealing device of the present invention can sufficiently follow the movement of the inner ring or the outer ring, prevents leakage of the lubricant, and prevents the lubricant from leaking between the inner ring and the outer ring. Foreign matter can be prevented from entering the gap from the outside. In addition, since the sealing material is formed by dividing into a plurality of arc-shaped sealing pieces, it is only necessary to replace the sealing piece at the damaged portion, and the replacement of the sealing material is easy and economical.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part showing an embodiment of a sealing device of the present invention.

FIG. 2 is a partially cutaway plan view of a slewing bearing equipped with the sealing device of the present invention.

FIG. 3 is an enlarged plan view of a portion A shown in FIG. 2;

FIG. 4 is an exploded perspective view showing a seal holding portion provided on the inner ring, with a part cut away.

FIG. 5 is a partially enlarged front view as viewed from a direction B shown in FIG. 4;

FIG. 6 is an enlarged sectional view for explaining the operation of the sealing device when a load acts on the outer race.

FIG. 7 is a partially enlarged plan view illustrating an operation of the sealing device when a gap between the outer ring and the inner ring is widened.

FIG. 8 is a partially enlarged plan view illustrating an operation of the sealing device when a gap between the outer ring and the inner ring is narrowed.

FIG. 9 is a partially cutaway perspective view of the slewing bearing.

FIG. 10 is a sectional view showing a conventional sealing device for a slewing bearing.

FIG. 11 is an explanatory view for explaining the operation of a conventional seal device for a slewing bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3 Ball 4 Slewing bearing 5 Clearance 6 Lubricant 7a, 7b Seal material 70a, 70b Seal piece 71a, 71b Seal lip 72a, 72b Seal body 73a, 73b Combined part 8a, 8b Seal holding part (seal insertion groove) 9a, 9b biasing member (spring)

Claims (3)

(57) [Scope of request for utility model registration] 1. A ring for a slewing bearing in which a ball is interposed between an inner ring and an outer ring, and the other of the inner ring and the outer ring is rotatably mounted on the inner ring, the ring being in close contact with the outer ring. A slewing bearing provided with a ring-shaped seal material, a ring-shaped seal material provided on the outer ring in close contact with the inner ring, and sealing oil filled in a gap between the inner ring and the outer ring with the seal material. In the sealing device, each of the sealing materials is divided into a plurality of arc-shaped sealing pieces, and each of the sealing pieces of the inner ring-side sealing material is formed so that the lubricant does not leak from between the sealing pieces. In combination with
The inner ring is equipped so as to be movable in the radial direction, and the seal pieces of the seal material on the outer ring side are combined so that the lubricant does not leak from between the seal pieces. A slewing bearing sealing device, which is movably mounted on the slewing bearing. 2. The seal device for a slewing bearing according to claim 1, wherein each of said seal pieces is composed of a seal lip having flexibility and a seal body supporting said seal lip. . 3. A seal holding portion for holding the seal piece movably in a radial direction is provided on each of the inner ring and the outer ring, and the seal lip is provided between the seal holding portion and the seal body. 3. A seal device for a slewing bearing according to claim 2, wherein a biasing member for biasing the inner bearing side is disposed on the inner side.