JP2008082487A - Oscillating bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a bearing ring of an oscillating bearing positioned in a housing from moving even when the bearing ring contacts a recessed arc-shaped part of the housing at a central part in the peripheral direction of an outer diameter face. <P>SOLUTION: The cross sectional shapes of a pin projection 6 of the bearing ring 1 for positioning the bearing ring 1 in the housing 11 and a pin hole 13 of the housing 11 are formed in elliptic shapes that engage with each other. Therefore, even when the bearing ring 1 contacts the recessed arc-shaped part 11a of the housing 11 at the central part in the peripheral direction of the outer diameter face 1b, rotation around the pin projection 6 of the bearing ring 1 is restricted by engagement of straight portions of the pin projection 6 and the pin hole 13, and the bearing ring 1 is prevented from moving. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rocking bearing in which a plurality of rollers are arranged on a concave arc-shaped raceway surface of a bearing ring fixed to a housing, and a convex arc-shaped portion of a movable member is swingably supported.

A swash plate type hydraulic pump, a hydraulic motor, or the like used in construction machinery, agricultural machinery, or the like incorporates a swing bearing that supports a movable member such as a swash plate in a swingable manner. An example of this type of rocking bearing is shown in FIGS. 5A and 5B (see Patent Document 1). In this oscillating bearing, a plurality of rollers 2 are arranged on a concave arc-shaped raceway surface 1 a of a raceway ring 1 fixed to a housing 11 while being held by a cage 3, and the swash plate or the like is movable by the plurality of rollers 2. The convex arcuate portion 12a of the member 12 is supported in a swingable manner. The bearing ring 1 has a pin projection 51, which has a convex arc-shaped outer diameter surface 1 b in contact with a concave arc-shaped portion 11 a of the housing 11 and projects vertically from the circumferential center position of the outer diameter surface 1 b. The concave arc-shaped portion 11a of the housing 11 is positioned by engaging with a pin hole 52 provided in the concave arc-shaped portion 11a. Note that the axial position of the pin projection is often provided at the center in the axial direction of the raceway surface, and may be shifted in the axial direction due to a problem in processing of the pin hole.
Japanese Patent Laying-Open No. 2002-286041 (FIG. 2)

By the way, as shown in FIG. 6 (a), the rocking bearing for positioning the raceway ring by the pin projection vertically projecting from the circumferential center position of the raceway outer diameter surface as shown in FIG. The radius of curvature _RH of the portion 11a is larger than the radius of curvature _RL of the outer diameter surface 1b of the bearing ring 1, and the outer diameter surface 1b of the race ring 1 contacts the concave arcuate portion 11a of the housing 11 at the circumferential center. In this case, as shown in FIG. 6B, there is a problem that the race 1 is easy to move around the pin protrusion 51 that engages with the pin hole 52 of the housing 11, and it is difficult to assemble the convex arcuate portion of the movable member. When the radius of curvature _RH of the concave arcuate portion 11a is smaller than the radius of curvature _{RL of} the raceway outer diameter surface 1b, and the raceway outer diameter surface 1b contacts the concave arcuate portion 11a at both ends in the circumferential direction. Since the race 1 is stabilized without moving, there is no such problem.

  An object of the present invention is to prevent a bearing ring positioned on a housing from moving even when the bearing ring of the rocking bearing is in contact with the concave arc-shaped portion of the housing at the circumferential center of the outer diameter surface. It is.

  In order to solve the above-described problems, the present invention provides a raceway having a concave arc-shaped raceway surface on an inner diameter surface and an outer diameter surface formed in a convex arc shape, and is arranged on the raceway surface of the raceway. A plurality of rolling rollers, and the outer ring surface of the bearing ring abuts on the concave arcuate portion of the housing, and the pin is integral with or separate from the bearing ring protruding vertically from the outer diameter surface of the bearing ring. A protrusion is engaged with a pin hole provided in the concave arc-shaped portion of the housing to position the raceway in the concave arc-shaped portion of the housing, and the convex arc-shaped portion of the movable member is shaken by the plurality of rollers. In the oscillating bearing that is movably supported, a configuration is adopted in which the cross-sectional shape of the pin protrusion and the pin hole has a straight portion in its contour.

  That is, the cross-sectional shape of the pin protrusion and pin hole has a straight portion in its contour, so that even when the race is in contact with the concave arcuate portion of the housing at the circumferential center of the outer diameter surface, The engagement of the projection and the straight portion of the pin hole restrains the rotation of the raceway around the pin projection so that the raceway does not move.

Further, in the above-described structure, when the position of the pin protrusions are offset from the axial center of the track surface, the axial length of the raceway surface L _L, the length of the rolling surface of the roller L _R , one side of the chamfer length of the roller when the C _R, axial distance x from the axial center of the raceway surface to the end on the side closer to the raceway surface side end of the pin projections, the following (1) It is desirable to satisfy the formula.
x <(L _R + C _R ) −L _L / 2 (1)

That is, as shown in FIG. 4, when shifting the position of the pin projections 6 from the axial center O of the raceway surface 1a of the axial length L _L in the axial direction, one side of the chamfered length in the length L _R of the rolling surface the two rollers of C _R, even when moving the pin protrusion 6 to the side edge opposite the raceway surface 1a, the side of the end closer to the axial center O on the raceway surface 1a side end of the pin protrusion 6 of the raceway surface 1a If the axial distance x to the portion satisfies the above formula (1), the rolling contact area with the raceway surface 1a of the roller 2 will not be disengaged from the engaging portion of the pin protrusion 6, and the pin The protrusion 6 can be pressed toward the concave arcuate portion of the housing to prevent the raceway from moving.

  In the oscillating bearing of the present invention, as described above, the pin protrusion for positioning the bearing ring to the housing and the pin hole of the housing that engages with the pin protrusion have linear portions in the outlines of the respective cross-sectional shapes. Therefore, even when the race is in contact with the concave arcuate portion of the housing at the circumferential center of the outer diameter surface, the movement of the race is restrained by the engagement of the pin protrusion and the straight portion of the pin hole. The convex arc-shaped portion of the movable member can be easily assembled.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 4. As shown in FIG. 1 (a), this oscillating bearing has a raceway ring 1 in which a concave arc-shaped raceway surface 1a is provided on an inner diameter surface and an outer diameter surface 1b is formed in a convex arc shape, and a raceway ring 1 A plurality of rollers 2 which are arranged on the raceway surface 1a and roll, and a cage 3 which holds these rollers 2 so that they can roll. The raceway ring 1 has an outer diameter surface 1b which is a concave circle of the housing 11. The roller 11 is fixed to the housing 11 in contact with the arcuate portion, and the plurality of rollers 2 support the convex arcuate portion 12a of the movable member 12 in a swingable manner.

  The track ring 1 is a press-formed product of a steel plate, and as shown in FIGS. 1B and 2A, the axial movement of the roller 2 is restricted at both axial ends of the track surface 1a. 4 is formed by flange bending. In addition, like the conventional example shown in FIG. 5, the hooks of the race rings may be provided only on either one of both end portions in the axial direction of the raceway surface. Moreover, the stopper 5 which controls the rocking | fluctuation of the holder | retainer 3 is formed in the both ends of the circumferential direction of the track surface 1a by the bending process. Note that this stopper is not necessarily provided.

  As shown in FIGS. 2 (a) and 2 (b), the bearing ring 1 has a pin projection 6 that protrudes perpendicularly from the outer diameter surface 1b by embossing at the axial center of the circumferential center portion. The pin hole 13 is formed in the concave arcuate portion 11 a of the housing 11 so as to face the pin protrusion 6. Each of the pin protrusion 6 and the pin hole 13 is formed in an oval shape whose cross-sectional shape extends in the circumferential direction, and when the pin protrusion 6 engages with the pin hole 13, the race 1 is a concave arc-shaped portion of the housing 11. 11a.

  This rocking bearing is configured as described above, and the cross-sectional shapes of the pin projection 6 of the bearing ring 1 and the pin hole 13 of the housing 11 for positioning the bearing ring 1 on the housing 11 are formed in an oval shape. Even when 1 is in contact with the concave arcuate portion 11a of the housing 11 at the center in the circumferential direction of the outer diameter surface 1b, the pin projection 6 and the pin hole 13 around the pin projection 6 of the race 1 are engaged by the engagement of the straight portions. The rotation can be restricted, and the convex arcuate portion 12a of the movable member 12 can be easily assembled.

  In addition, the cross-sectional shape of the pin protrusion and the pin hole is not limited to the oval shape extending in the raceway circumferential direction as in the above-described embodiment, and may be any shape having a straight line portion in the outline. Therefore, for example, as shown in FIG. 3, it may be an oval shape extending in the direction of the race ring axis, or may be a polygon such as a triangle or a quadrangle. In the above-described embodiment, the pin protrusion is integrally formed on the outer diameter surface of the race ring by embossing. However, the pin projection is attached to the outer diameter surface of the race ring by fitting or the like, and the pin projection is formed separately. You can also.

Furthermore, in the above-described embodiment, the pin protrusion is provided at the center in the axial direction of the raceway surface. However, depending on the problem in processing the pin hole, the position of the pin protrusion may be shifted in the axial direction. In this case, as shown in FIG. 4, even if the roller 2 moves to the side end of the raceway surface 1 a opposite to the pin projection 6, the rolling contact area with the raceway surface 1 a of the roller 2 is the pin projection 6. It is desirable not to disengage from the engaging portion. For example, when the axial length L _L = 20.2 mm of the raceway surface 1 a, the length L _R = 19 mm of the rolling surface of the roller 2, and the chamfering length C _R = 0.5 mm on one side of the roller 2, the raceway If the axial distance x = 6 mm from the axial center O of the surface 1a to the end of the pin protrusion 6 on the side close to the end of the raceway surface 1a, the aforementioned equation (1) is satisfied, and the raceway surface of the roller 2 is satisfied. Since the rolling contact area with 1a does not come off from the engaging portion of the pin protrusion 6, the pin protrusion 6 is surely pressed toward the concave arcuate portion 11a side of the housing 11 so that the race ring 1 does not move. Can do.

a is a longitudinal front view of the rocking bearing of the embodiment, b is a cross-sectional plan view taken along line II of a. a is an exploded perspective view for explaining the positioning method of the bearing ring in FIG. 1, and b is an enlarged vertical sectional view of a main part in FIG. Exploded perspective view showing a modification of the pin protrusion and pin hole Top view explaining the positional relationship between rollers and pin projections a is a longitudinal front view of a conventional rocking bearing, and b is a perspective view of a bearing ring of a. a is a longitudinal front view showing an example of a contact state between the race and the housing, and b is a plan view of a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Race ring 1a Raceway surface 1b Outer diameter surface 2 Roller 3 Cage 4 Cage 5 Stopper 6 Pin protrusion 11 Housing 11a Concave arcuate part 12 Movable member 12a Convex arcuate part 13 Pin hole

Claims (2)

  A raceway having a concave arc-shaped raceway surface on an inner surface and an outer diameter surface formed in a convex arcuate shape, and a plurality of rollers arranged and rolled on the raceway surface of the raceway, the raceway The outer ring surface of the ring is brought into contact with the concave arcuate portion of the housing, and a pin projection that is integral with or separate from the raceway ring that protrudes perpendicularly from the outer diameter surface of the raceway ring is provided on the concave arcuate portion of the housing. A rocking bearing that engages with a pin hole, positions the race on a concave arcuate portion of the housing, and swings the convex arcuate portion of the movable member with the plurality of rollers, A rocking bearing characterized in that the cross-sectional shape of the protrusion and the pin hole has a straight portion in its contour. The position of the pin protrusion is shifted from the axial center of the raceway surface, the axial length of the raceway surface is L _L , the length of the rolling surface of the roller is L _R , and the chamfer length on one side of the roller. the when the C _R to the axial distance x from the axial center of the raceway surface to the end on the side closer to the raceway surface side end of the pin projections and so as to satisfy the following formula (1) The rocking bearing according to claim 1.
x <(L _R + C _R ) −L _L / 2 (1)

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