JP2002339979A - Single row ball turning bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single row ball turning bearing capable of smoothly turning a turntable under a partial load. SOLUTION: A holder 6 for holding balls in the circumferential direction between raceway surfaces of inner and outer rings is divided into a plurality of segments 6a in the circumferential direction, a pocket 11a is provided in an end part of each segment 6a, and a ball 5 is inserted between the segments 6a, and a space is provided between the segments 6a. Then, the moment load associated with the partial load on the turntable is applied to the bearing, no tensile load or compressive load is applied to the holder even when the relative advance/delay phenomenon of the ball occurs, the bearing is smoothly turned so that the turntable can be turned by the consistent turning torque, and the interference between the segments 6a is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-row ball slewing bearing for rotatably supporting a turntable.

[0002]

2. Description of the Related Art A slewing bearing for rotatably supporting a turntable used for various machines such as a construction machine, a cargo handling machine, a machine tool, and various devices such as a parabolic antenna and a rotating stage is a ball bearing type, a roller. There are various types such as a bearing type and a cross roller type. This slewing bearing
In addition to the axial load and the radial load, a moment load is also applied along with the eccentric load applied to the turntable.

As shown in FIG. 5, each of the raceway surfaces 3 and 4 of the inner ring 1 and the outer ring 2 is formed by two curved surfaces, respectively.
A single-row ball slewing bearing that holds a plurality of single-row balls 5 between the raceway surfaces 3 and 4 with a retainer 6 and makes each ball 5 contact the raceway surfaces 3 and 4 at four points is a rolling element. Since the ball 5 is firmly held between the two raceway surfaces 3 and 4 and the rigidity of the inner and outer races 1 and 2 formed integrally with each other is high, a high load capacity can be obtained with a simple configuration.

In this single-row ball slewing bearing, a gear 9 meshing with the drive shaft of the turntable is provided on the inner periphery of the inner ring 1 so that the inner ring 1 rotates together with the turntable. In some cases, a gear is provided on the outer periphery of the outer ring, and the outer ring is rotated together with the turntable.

As shown in FIGS. 6 (a) and 6 (b), the retainer 6 is formed in a full circle or a missing circle, and in the circumferential direction thereof,
As shown in FIG. 6C, a plurality of pockets 11 for holding the balls 5 one by one are provided. Each pocket 11
Is formed in a circular shape substantially equal to the diameter of the ball 5.

[0006]

In the single row ball slewing bearing, when the turntable turns while receiving an eccentric load,
The contact angle of each ball in contact with the raceway surface changes individually due to the moment load caused by the unbalanced load. As described above, when the contact angles of the balls individually change, the orbit diameters of the balls are different for each ball, and a relative advance / delay phenomenon occurs for the balls.

For this reason, in the conventional single-row ball slewing bearing described above, a tensile load or a compressive load acts on the cage for holding the ball, which hinders smooth rotation of the bearing and fluctuates in the slewing torque of the turntable. There is a problem that occurs. Further, the cage may be damaged due to repeated tensile load and compressive load.

An object of the present invention is to provide a single-row ball slewing bearing that can smoothly turn a turntable that receives an eccentric load.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to an inner ring and an outer ring in which each of the raceways is formed by two curved surfaces, and a plurality of balls in a single row are interposed between the raceways. Are held in the pocket of the cage in the circumferential direction, and when a load is applied, in a single row ball slewing bearing in which these balls make four-point contact with the raceway surfaces of the inner and outer rings, the cage is divided into a plurality of segments in the circumferential direction. And a pocket is provided at the end of each segment, a ball is inserted between the segments, and a gap is provided between the segments.

In other words, by dividing the cage for holding the ball in the circumferential direction between the raceway surfaces of the inner and outer races into a plurality of segments in the circumferential direction, even if the relative advance / delay phenomenon of the ball due to the moment load occurs. , 1
Since it can be avoided individually in the segment, no tensile load or compressive load acts on the cage, the bearing rotates smoothly, and
The cage is not damaged.

According to the present invention, a pocket is provided at an end of each segment, a ball is inserted between the segments, and a gap is provided between the segments, so that interference due to contact between the segments is prevented. ing.

Further, in the present invention, by forming chamfers at the axial corners of both ends of each segment,
Even if each segment meanders due to the advance or delay of the ball,
Both end corners in the axial direction of each segment can prevent contact with other components such as a seal and a mounting base.

Further, according to the present invention, by forming chamfers on the inner and outer surfaces in the circumferential direction of both ends of each segment, when each segment rises to the inner diameter side of the outer ring or the outer diameter side of the inner ring, each segment is formed. Can be prevented from contacting the inner and outer surfaces with the inner diameter surface of the outer ring or the outer diameter surface of the inner ring at both ends. As the chamfer, a tapered surface or a curved surface can be adopted.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This single row ball slewing bearing
As shown in FIG. 1, each of the raceways 3, 4 of the inner race 1 and the outer race 2 is formed by two curved surfaces, respectively.
A plurality of balls 5 in a single row are held by a retainer 6 therebetween, and each ball 5 comes into contact with each of the raceway surfaces 3 and 4 at four points. Grease is filled between the raceway surfaces 3 and 4 on which the balls 5 are held, and upper and lower ends thereof are respectively provided with sealing members 7.
Sealed by a and 7b.

The inner ring 1 is provided with a screw hole 8 for attaching a turntable, and a gear 9 meshing with a drive shaft of the turntable is provided on the inner periphery thereof. The outer race 2 is provided with a bolt hole 10 for attachment to a fixed seat. Although not shown, the inner ring 1 has a ball 5
Is provided between the raceway surfaces 3 and 4, and this hole is closed with a stopper plug.

As shown in FIG. 2A, the retainer 6 is formed by equally dividing a ring-shaped one into six segments 6a in the circumferential direction. As shown in FIG. Each segment 6a is provided with a plurality of pockets 11 for holding the balls 5 one by one.

At the end of each segment 6a, a pocket 11a into which the ball 5 is inserted is provided, the ball 5 between the segments 6a is inserted, a gap is provided between the segments 6a, and the contact between the segments 6a is made. To prevent interference.

As shown in FIG. 4, chamfers 12 are formed at the corners in the axial direction of both ends of each segment 6a, so that each segment 6a
In the meanwhile, even when the meandering is meandering, the interference caused by the contact between the both end corners in the axial direction of each segment 6a and other parts such as the seal and the mounting base is reduced.

Further, as shown in FIG. 4, chamfers 13 are formed on the inner and outer surfaces of both ends of each segment 6a in the circumferential direction so that each segment 6a rises to the inner diameter side of the outer ring or the outer diameter side of the inner ring. In this case as well, interference caused by contact between the inner and outer surfaces of both ends of each segment 6a and the inner surface of the outer ring or the outer surface of the inner ring is reduced.

As the chamfers 12 and 13, a tapered surface or a curved surface can be adopted.

[0021]

As described above, in the single-row ball slewing bearing of the present invention, the cage is divided into a plurality of segments in the circumferential direction, a pocket is provided at an end of each segment, and a ball is provided between the segments. By inserting and providing a gap between each segment, even if the relative advance / delay of the ball due to the moment load occurs, the advance / delay of the ball can be avoided individually in one segment. No load or compression load is applied, the bearing rotates smoothly, and the cage is not damaged. Also, interference due to contact between the segments can be prevented.

Further, by forming chamfers at the corners in the axial direction at both ends of each segment, even if each segment meanders due to the advance / delay of the ball, the both ends in the axial direction of each segment are sealed. And other parts such as the mounting base can be prevented from contacting.

Further, by forming chamfers on the inner and outer surfaces in the circumferential direction of both ends of each of the segments, when each segment floats on the inner diameter side of the outer ring or the outer diameter side of the inner ring, both ends of each segment are formed. The contact between the inner and outer surfaces and the inner diameter surface of the outer ring or the outer diameter surface of the inner ring can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a single-row ball slewing bearing according to an embodiment of the present invention.

2A is a plan view of a retainer portion of FIG. 1, and FIG.

FIG. 3 is a partially enlarged plan view of a retainer part of FIG. 1;

FIG. 4 is an enlarged perspective view of the end of the cage shown in FIG. 1;

FIG. 5 is a longitudinal sectional view showing a conventional single-row ball slewing bearing.

6A is a plan view of a conventional cage, b is a plan view of another conventional cage, and c is a partially omitted development view of a or b. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 3, 4 Raceway surface 5 Ball 6 Cage 6a Segment 7a, 7b Sealing member 8 Screw hole 9 Gear 10 Bolt hole 11, 11a Pocket 12, 13 Chamfer

Claims (5)

[Claims] An inner race and an outer race each have two raceway surfaces.
Formed of two curved surfaces, between which a plurality of balls in a single row are circumferentially held in pockets of the cage, and when a load is applied, these balls make four-point contact with the raceways of the inner and outer rings. In the single-row ball slewing bearing, the cage is divided into a plurality of segments in the circumferential direction, pockets are provided at ends of the segments, balls are inserted between the segments, and gaps are provided between the segments. Single-row ball slewing bearing. 2. The single-row ball slewing bearing according to claim 1, wherein a chamfer is formed at an axial corner at both ends of each segment. 3. The single-row ball slewing bearing according to claim 1, wherein chamfers are formed on the inner and outer surfaces in the circumferential direction of both ends of each of the segments. 4. The chamfer according to claim 2, wherein the chamfer is a tapered surface.
Or the single-row ball slewing bearing according to 3. 5. The single-row ball slewing bearing according to claim 2, wherein the chamfer is a curved surface.