JPH083475Y2 - Slewing bearing seal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a seal device for a slewing bearing of a construction machine such as a hydraulic excavator.

[Prior Art] Fig. 4 shows a side view of a hydraulic excavator as an example of a construction machine.

1 is a lower traveling body, 2 is an upper swing body, 3 is a swing bearing, 4 is a front attachment, and the upper swing body 2 is
Is rotatably supported by the lower traveling body 1 via a slewing bearing 3.

FIG. 5 shows a sectional structure of a mounting portion of a conventionally known slewing bearing 3.

Reference numeral 11 denotes an outer ring, which is a component of the swivel belling 3, and is fastened and fixed to the main frame 13 of the upper swivel body 2 by a suitable number of bolts 12 arranged on the circumference.

Similarly, the inner ring 14 which is fastened and fixed to the lower frame 16 of the lower traveling body 1 by a suitable number of bolts 15 arranged on the circumference has a ring gear 17 inside and is driven by a turning pinion (not shown). While being able to turn with respect to the outer ring 11.

Reference numeral 22 is a pinion chamber for accommodating the pinion, in which a small amount of lubricating grease is initially supplied.

A plurality of balls 18 and spacers (not shown) are alternately arranged between the outer race 11 and the inner race 14 to receive thrust load, moment load and the like.

During excavation work and turning work of a shovel, a large compressive load is applied to the raceways 11a, 14a of the ball 18, the outer ring 11, and the inner ring 14.
Therefore, the raceway surface is filled with grease for smooth operation.

Further, in order to reduce the loss due to the frictional force during rotation of the ball 18, some clearance is provided between the raceway surfaces 11a, 14a and the ball 18.

After protecting the raceway surface, the grease descends due to gravity and accumulates in the grease reservoir 19.

Rubber seals 20 and 21 are usually provided above and below the grease reservoir 19 for the purpose of preventing dust and metal powder from entering the track and preventing grease from flowing out.

One of the seals 20 and 21 is attached to the outer periphery of the lower portion of the inner ring 14 and the other 21 is attached to the upper inner periphery of the outer ring 11, and the tip lip portion of the seal 20 attached to the inner ring 14 is the lower surface 11 of the outer ring 11.
Further, the tip lip portion of the seal 21 attached to the outer ring 11 contacts the upper surface 14b of the inner ring to form a closed space, and grease is held in the closed space, that is, the grease reservoir 19. (For example, see Japanese Utility Model Laid-Open No. Sho 63-190348) [Problems to be Solved by the Invention] In the above-described conventional structure, the attachment 4 during work is attached.
And the moment acting on the slewing bearing 3 changes, the gap between the raceway surfaces 11a and 14a and the ball 18 causes
The outer ring 11 and the inner ring 14 move up and down relatively in the direction of the arrow in FIG.

As a result, the seal attached to the lower outer periphery of the inner ring 14
The tip lip portion of 20 cannot keep up with the movement of the outer ring 11, and the weight of the grease accumulated in the grease reservoir 19 causes it to open.
However, there is a problem that the outer surface of the vehicle is contaminated and eventually the contaminated grease is scattered and dropped on the road surface, resulting in pollution of the natural environment.

In order to solve this problem, the applicant of the present invention has proposed that the lip of the lower seal has a bifurcated shape.
Since the lower seal is attached to the outer surface of the inner ring which is vertically raised, the base end of the lower seal must be attached in the horizontal direction, and the weight of the grease accumulated in the grease reservoir causes the seal to be sealed. However, it has not been possible to solve the problem that the portion bends downward with the base end portion as a fulcrum and opens freely, causing grease leakage.

The present invention aims to solve the above problems.

[Means for Solving the Problem] The present invention provides means for solving the above-mentioned problems, and is an outer ring 11 fixed to a base plate 13 of an upper swing body 2 and a lower portion of a lower traveling body 1. In a revolving bearing sealing device in which a ball 18 is arranged between the inner ring 14 fixed to the frame 16 and the upper and lower spaces of the ball 18 are sealed by a rubber seal, an upper seal
21 has a V-shaped cross section, the base end portion of which is fitted in a groove provided on the inner peripheral surface of the outer ring 11 and is attached in the horizontal direction, and the tip lip portion is curved downward and is provided on the upper surface 14b of the inner ring 14. The lower frame 16 that comes into contact with the lower seal 23 has a Y-shaped cross section that is symmetrical inside and outside, and the base end portion of the lower frame 16 projects outward from the outer circumference of the inner ring 14.
Of the bifurcated tip lip portion which is fitted in a groove 16a or a protrusion 16b provided on the upper surface of the protruding portion of the projection 16b and is attached in the vertical direction, and which is symmetrical inside and outside contacts the lower surface 11b of the outer ring 11 separately. The gist of the invention is a slewing bearing seal device characterized by the following.

[Embodiment] The configuration of the present invention will be described with reference to FIGS. 1 and 2.

The basic structure of the slewing bearing 3 is exactly the same as that of the conventional example shown in FIG.

That is, the balls 18 are arranged between the outer ring 11 fixed to the base plate 13 of the upper revolving structure 2 and the inner ring 14 fixed to the lower frame 16 of the lower traveling structure 1, and the upper and lower spaces 19 of the balls 18 are made of rubber. The point where the seals 21 and 23 are used for sealing is as conventionally known.

As shown in FIG. 5, one of the conventionally known seals is
20 is attached to the lower outer periphery of the inner ring 14 and the other 21 is attached to the upper inner periphery of the outer ring 11 in a horizontal direction, and the tip lip portion of the seal 20 attached to the inner ring 14 is curved upward so that the lower surface of the outer ring 11 is curved. The tip lip portion of the seal 21 attached to the outer ring 11 was curved downward and was in contact with the upper surface 14b of the inner ring 11b.

In the present invention, the upper seal 21 of the upper and lower seals 21 and 23 is mounted horizontally as in the conventional example, but the lower seal 23 is mounted vertically.

The upper seal 21 has a V-shaped cross section, and the base end is the outer ring 11
Is fitted in a groove provided on the inner peripheral surface of the inner ring 14 and is attached in the horizontal direction.
Is in contact with This point is the same as the conventional example shown in FIG.

As mentioned above, the upper seal 21 is mounted horizontally as is conventionally known, while the lower seal 23 is
Has a Y-shaped cross-section whose inner and outer symmetry is symmetrical, and its base end portion is formed in a groove 16a or a protrusion 16b provided on the upper surface of the protruding portion of the lower frame 16 protruding outward from the outer periphery of the inner ring 14. It is fitted and attached in the vertical direction, and the bifurcated tip lip parts that are symmetrical inside and outside are evenly divided inside and outside, and the lower surface 11 of the outer ring 11 is
touching b.

That is, the diameter of the lower frame 16 is set to be larger than the diameter of the inner ring 14, the outer frame of the inner ring 14 is projected outward, and the groove 16a or the protrusion 16b is provided on the upper surface of the projecting portion to vertically support the lower seal 23. It is something that is done.

[Operation] The present invention is configured as described above, and has upper and lower seals.
Of 21,23, the mounting structure of the upper seal 21 is the same as that of the conventional example shown in FIG. 5, but the lower seal 23 is mounted in the vertical direction, and its tip lip portion is a bifurcated inner and outer opening. Since it is in the shape of a circle, it is evenly divided into the inside and outside and double contacts with the lower surface 11b of the outer ring 11, so when grease accumulates in the grease reservoir 19, the sealing performance is not affected by the weight of the grease. Even if the outer ring 11 and the inner ring 14 move up and down relative to each other, the seal 23 is attached in the vertical direction, so that the seal 23 has a bifurcated shape and has a tip lip portion that is evenly opened inward and outward. It is possible to follow the vertical movement of the outer ring 11 by changing the opening and closing width, to maintain contact with the lower surface 11b of the outer ring 11, and to maintain the sealed state of the slewing bearing to prevent grease from flowing out.

[Effect] According to the present invention, the lower seal 23 of the upper and lower seals 21, 23 has a Y-shaped cross-sectional shape with inner-outer symmetry, and the lower end thereof projects outward from the outer periphery of the inner ring 14. 16 Fits in a groove 16a or a protrusion 16b provided on the upper surface and is mounted in the vertical direction, and since the forked tip lip portions are evenly divided inside and outside to contact the lower surface 11b of the outer ring 11, a load is applied during the work. The moment acting on the slewing bearing 3 is changed due to the fluctuation of, and even if the outer ring 11 and the inner ring 14 of the slewing bearing 3 are vertically moved relative to each other, the tip lip portion of the seal 23 is
The bottom surface 11b can be kept in contact with the bottom surface 11b at all times, and the grease can be prevented from flowing out, which is very useful for environmental protection and improvement of maintainability.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of the present invention, FIG. 2 is an enlarged view of part A of FIG. 1, FIG. 3 is a modification thereof, FIG. 4 is a side view of a hydraulic excavator, and FIG. It is a side view. 1: Undercarriage 2: Upper revolving structure 3: Revolving bearing 11: Revolving bearing outer ring 11a: Raceway surface, 11b: Lower surface 12: Bolt 13: Upper revolving structure base plate 14: Revolving bearing inner ring 14a: Raceway surface, 14b : Upper surface 15: Bolt 16: Lower frame of lower traveling body 16a: Groove, 16b: Protrusion 17: Ring gear 18: Ball 19: Grease reservoir 20: Lower seal (conventional example) 21: Upper seal 22: Pinion chamber 23: Lower seal

Claims (1)

[Scope of utility model registration request] 1. A base plate (13) for an upper swing body (2).
A ball (18) is arranged between the outer ring (11) fixed to the inner ring (14) and the inner ring (14) fixed to the lower frame (16) of the lower traveling body (1). In a slewing bearing sealing device in which a rubber seal is used, the upper seal (21) has a V-shaped cross section, and the base end is fitted in a groove provided on the inner peripheral surface of the outer ring (11). And attached in a horizontal direction, the tip lip bends downward and contacts the upper surface (14b) of the inner ring (14), and the lower seal (23) has a Y-shaped cross section with inner and outer symmetry. The end portion is fitted in a groove (16a) or a protrusion (16b) provided on the upper surface of the lower frame (16) protruding outward from the outer periphery of the inner ring (14), and is vertically attached, The bifurcated tip lip that is symmetrical inside and outside is divided into the inside and outside and contacts the lower surface (11b) of the outer ring (11). Sealing apparatus of a slewing bearing according to claim.