JP4708222B2 - Roller bearing - Google Patents

Description

  The present invention relates to a roller bearing in which a spacer is interposed between rolling elements instead of a cage.

Patent Document 1 discloses a roller bearing in which a spacer is interposed between adjacent rollers. This type of roller bearing can incorporate more rollers in the bearing and can obtain a high load capacity. However, the roller bearing described in Patent Document 1 inevitably restricts the movement of the spacer by the raceway surface and the collar side surface of the inner ring and the outer ring, so that the spacer is necessarily the same size as the radial cross section of the roller. Therefore, there is a tendency that the stirring resistance of the lubricating oil is large. Further, since the spacer is slid on the raceway surface and the collar side surface of the inner ring or the outer ring, smooth oil film formation on the rolling surface and the collar side surface may be impaired.
Japanese Patent No. 3549530

  In order to eliminate the above-described problems of the roller bearing described in Patent Document 1, the present applicant previously described in FIG. 7 in the roller bearing in which the spacer is interposed between the rollers, the axial direction of the spacer. It has been proposed to restrict the movement of the spacer in the axial direction by providing extended portions with surfaces facing the roller end surfaces at both ends (Japanese Patent Application No. 2005-253746). By adopting such a configuration, the movement of the spacer in the axial direction can be restricted by the end portion of the expansion portion, and the movement in the radial direction can be restricted by the roller rolling surface or the inner ring collar outer diameter or outer ring collar. It can be regulated by the inner diameter. That is, since the inner ring and outer ring raceway surfaces and flange side surfaces are not used as spacer movement restricting means, there is no need to interpose the spacer over a wide area between adjacent rollers, and the stirring resistance of the lubricating oil can be suppressed. Also, oil film formation on the rolling surface and the collar side surface is not hindered. Further, when the spacer is guided to the inner ring collar outer diameter or the outer ring collar inner diameter, the expansion portion also exerts an effect of expanding the guide area, so that an oil film is easily formed on the guide surface.

  A main object of the present invention is to improve the strength of a spacer in a roller bearing in which a spacer is interposed between adjacent rollers.

This onset Ming, a plurality of rollers rollably interposed between the inner ring raceway surface and the outer ring raceway surface, the roller bearing having a spacer between rollers adjacent, injection molding said spacer is a synthetic resin It has a roller-shaped contact surface that contacts the rolling surface of the roller on both sides, and has a surface facing the roller end surface by extending both ends in the circumferential direction in the circumferential direction. Yes and extension forms, in a cross section perpendicular to the bearing circumferential direction of the spacer, the inner side of the bearing radial direction of the spacer toward Ku surface is formed flush, including the extension, the towards a plane from the extended portion toward the outside of the bearing radial direction of the spacer to form a slope portion of and flush with the same gradient, or surface facing the outside of the bearing radial direction of the spacer is the extension And the same from the extended part toward the inner surface of the spacer in the radial direction of the bearing. Forming an inclined surface portion of and flush with a gradient, said spacer, by providing the inside or only one gate on the surface facing the outside of the bearing radial contact line direction of the place the spacer to the resin flow direction (Claim 1) .
Further, the present invention provides a roller bearing having a plurality of rollers that are freely rollable between an inner ring raceway surface and an outer ring raceway surface, and a spacer between adjacent rollers. It is a plate that is integrally formed by molding, has roller contact surfaces that contact the roller rolling surfaces on both sides, and has a surface that faces both ends of the roller by extending both ends in the circumferential direction in the circumferential direction. An extension portion is formed, and in a cross section perpendicular to the bearing circumferential direction of the spacer, a surface facing the outer side of the spacer in the radial direction of the bearing is formed to be flush with the extension portion, and the extension Forming a slope portion having the same gradient and flush with the surface facing the inner side of the bearing in the radial direction of the spacer, and only one surface of the spacer facing the inner side or the outer side of the bearing radial direction. By providing a gate, the flow direction of the resin with respect to the contact line direction with the spacer Is characterized in that the allowed interlinked (claim 2).
By adopting such a configuration, establishment of breakage of the spacer can be reduced. That is, on the upper surface of the spacer (for example, the surface facing the outer side in the bearing radial direction of the spacer ) or the lower surface (for example, the surface facing the inner side of the bearing in the radial direction of the bearing ), Stress concentration can be avoided. In other words, it is possible to reduce the number of corners that are the starting point of stress concentration in the spacer.
As a configuration of the spacer in a cross section perpendicular to the circumferential direction of the bearing, the surface facing the inner side of the bearing in the radial direction of the spacer is formed to be flush with the extended portion and from the extended portion to the radial direction of the bearing. Formed with the same slope and the same slope toward the outside facing surface , or the face facing the outside in the bearing radial direction of the spacer is formed flush with the extended portion and expanded While forming the slope part of the same gradient and flush with the surface facing the inner side of the bearing radial direction of the spacer from the part, by adopting either one, while avoiding the occurrence of the stress concentration, Heat generation during operation of the bearing can be reduced. That is, by extending the gradient of the expansion portion toward the axial center of the spacer, it is not necessary to extend the expansion portion from the inner diameter side to the outer diameter side of the spacer, so the bearing radius of the expansion portion The size of the direction can be reduced, and the stirring resistance of the lubricating oil can be reduced. Moreover, the contact length of a roller rolling surface and a spacer can be shortened by extending | stretching of the said gradient shape. Furthermore, since the area where the spacer covers the roller rolling surface is reduced, the cooling efficiency by the lubricating oil can be improved.

For example, when the extended portion is formed as shown in FIG. 7, stress concentrates on the corners of the upper and lower surfaces. In addition to the compressive stress in the circumferential direction of the bearing, bending stress to the extension may act on the spacer. That is, since the spacer has a degree of freedom in the circumferential clearance of the bearing, the posture of the spacer may be disturbed, and a force may act on the extended portion from the roller end face. In particular, when the corner is located in the vicinity of the thin portion of the spacer, there is a possibility that a crack may occur at the base of the extended portion starting from the corner.

According to a third aspect of the present invention, in the roller bearing of the first or second aspect, a notch portion is provided on a surface facing the inner side or the outer side in the radial direction of the bearing at the central portion in the longitudinal direction of the spacer. is there. The presence of the notch not only helps to reduce the agitation resistance of the lubricating oil, but also the surface facing the inside or outside in the radial direction of the bearing formed by the notch can be used as a surface for providing the gate.

According to a fourth aspect of the present invention, in the roller bearing of the first , second, or third aspect, the clearance Sa between the expansion portion and the end surface of the spacer is S in the circumferential direction, Lw in the roller length, When the maximum value of the extension portion length is L, it is within the range represented by Formula 1.

Referring to the roller bearing according to claim 1 again, the spacer is formed by injection molding of synthetic resin, by adopting the configuration in which only provided one gate spacer, to avoid the occurrence of weld And local reduction in strength can be avoided. If the spacer has a through hole, although not essentially generate the weld is inevitable, it is possible to keep the weld occurred in one place by adopting a point gate.

Further, the spacer, by adopting the configuration of arranging the gate radially inner or surface facing the outside of the bearing, the flow direction of the resin and the contact line direction of the rollers and the spacers orthogonal As a result, the crushing strength of the spacer can be improved.

  In general, an injection-molded product has a lower strength in the direction perpendicular to the flow direction of the resin, and this tendency appears more prominently in resin materials containing fibers. In particular, when receiving a line load along the direction of the fiber, the effect of fiber reinforcement cannot be obtained sufficiently. Here, the spacer receives a compressive force through the line contact of the roller rolling surface during the operation of the bearing. Therefore, the crushing strength can be improved by making the flow direction of the resin in the spacer perpendicular to the contact line direction of the spacer. In terms of the crushing strength, it is desirable to provide a gate over the entire contact position of the spacer and make the direction of compressive force to the spacer and the flow direction of the resin the same. There is a problem with slidability with the moving surface, which is not realistic.

  According to the present invention, in a roller bearing in which a spacer is interposed between adjacent rollers, the probability of breakage of the spacer can be reduced. Further, the stirring resistance of the lubricating oil during the operation of the bearing can be reduced, and heat generation on the roller rolling surface and the sliding surface of the spacer can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, for convenience, a cylindrical roller bearing as an example of a roller bearing will be described with reference to FIG. 2. The cylindrical roller bearing includes an inner ring 2, an outer ring 4, a cylindrical roller 6, and a spacer 8. The cylindrical roller 6 can roll between the raceway surface of the inner ring 2 and the raceway surface of the outer ring 4, and a spacer 8 is interposed between the adjacent cylindrical rollers 6. The spacer 8 is generally plate-shaped, and has a surface that contacts the rolling surface 6a of the cylindrical roller 6, that is, a roller contact surface 8a, on both surfaces thereof. At both ends of the spacer 8 in the longitudinal direction, extended portions 8b having surfaces facing the roller end surface 6b of the cylindrical roller 6 are formed.

The embodiment shown in FIG. 1 is an example in which the upper and lower surfaces including the extended portion 8b of the spacer 8 are formed linearly, that is, flush with each other. As shown in the figure, since no step (corner) is formed at the base of the extended portion 8b except in the extended direction, concentration of stress can be avoided.

Embodiment shown in FIG. 3 is a straight upper surface of the spacer 8 including an extension 8b, i.e. formed flush, an example in which the lower surface of the extension portion 8 b is formed at the slope. In this case, the slope extends in a straight line, that is, flush with the roller contact surface 8a. In other words, the gradient is the same from the region of the extended portion 8b to the region of the roller contact surface 8a. By adopting such a configuration, the lower corner portion of the extended portion 8b is cut compared to the extended portion having a rectangular cross section, and the lower corner portions of both ends of the roller contact surface 8a are also cut. In addition to reducing the agitation resistance of the lubricating oil, the contact length between the rolling surface 6a of the roller 6 and the spacer 8 is shortened to reduce heat generation. In FIG. 3, the gradient shape is connected to the vertical surface via a gentle arc, but the gradient shape may be extended to the lowermost surface of the spacer 8.

In FIG. 4, the movement of the spacer 8 to be inclined in the circumferential clearance of the bearing is not restricted by the extended portion 8 b and the end face 6 b but by the contact of the spacer 8 and the rolling surface 6 a. This shows the state, and the force applied from the roller end face 6b to the extended portion 8b of the spacer 8 can be greatly reduced. For example, the internal specifications of the cylindrical roller bearing NJ2324E (φ120 × φ260 × 86) shown in FIG. 2 are as follows: circumferential clearance S = 1.5 mm, roller length Lw = 62 mm, spacer extension portion length L = 20 mm. Therefore, the clearance Sa between the extended portion 8b of the spacer 8 and the end surface 6b should be 0.53 mm or more. If this is expressed by a formula, it is as shown in Formula 1.

  FIG. 5 shows a resin spacer 8 formed by injection molding, and an injection-molded gate 10 is arranged at one position on the lower surface of the spacer 8, in other words, the surface facing the inside in the radial direction of the bearing. Here, in order to reduce the flow resistance of the lubricating oil, the lower center of the spacer 8 is notched as indicated by reference numeral 8c, and the gate 10 is provided on the lower surface of the notch. Since the spacer 8 does not have a portion in which the resin material is divided into two, such as a through hole, for example, a weld portion is not generated by setting the gate 10 to one location.

  Further, since the gate 10 is arranged on the lower surface of the spacer 8, the flow direction of the resin in the spacer 8 is orthogonal to the contact line direction with the spacer 8 and 6. Will improve. FIG. 6 shows a case where the gate 10 is arranged at the end of the spacer 8 for comparison. In this case, as indicated by the arrows, the flow direction of the resin is parallel to the contact line direction between the spacers 8 and 6, which is not desirable from the viewpoint of the crushing strength of the spacers 8. It should be noted that the gate 10 should be provided at a position that avoids contact with other components, and is preferably provided at a place that is not conspicuous when assembled in the bearing. Both ends are removed for the reasons described above in connection with FIG. 6 and the roller contact surface 8a is removed for contact with the roller 6, so that the lower surface (FIG. 5) or upper surface of the spacer 8 is the gate 10 It can be said that it is suitable for installation. These are the surfaces facing inward or outward in the radial direction of the bearing.

(A) is the front view of the spacer which shows an Example, (B) is a perspective view. Broken perspective view of a roller bearing showing another embodiment Front view of the spacer in the bearing of FIG. Plan view showing rollers adjacent to each other via a spacer A perspective view of a spacer showing another embodiment A perspective view of a spacer showing a comparative example (A) is a broken perspective view of a roller bearing, (B) is a front view of a spacer in the bearing of FIG. 7 (A).

Explanation of symbols

2 Inner ring 4 Outer ring 6 Cylindrical roller 6a Rolling surface 6b Roller end surface 8 Spacer 8a Roller contact surface 8b Expansion portion 8c Notch 10 Gate

Claims (4)

In a roller bearing having a plurality of rollers movably interposed between an inner ring raceway surface and an outer ring raceway surface, and a spacer between adjacent rollers,
The spacer is a plate formed integrally by synthetic resin injection molding, has a roller contact surface that contacts the roller rolling surface on both sides, and both ends in the longitudinal direction extend in the circumferential direction. An extension with a surface facing the roller end face is formed,
In a cross section perpendicular to the bearing circumferential direction of the spacer, the inner side of the bearing radial direction of the spacer toward Ku surface is formed flush, including the extension, the bearing of the spacer from the extended portion Forming the same slope and the same slope toward the radially outward surface,
Rollers characterized in that the flow direction of the resin is orthogonal to the contact line direction with the spacer by providing a single gate on the surface of the spacer facing the inner or outer side in the bearing radial direction. bearing. In a roller bearing having a plurality of rollers movably interposed between an inner ring raceway surface and an outer ring raceway surface, and a spacer between adjacent rollers,
The spacer is a plate formed integrally by synthetic resin injection molding, has a roller contact surface that contacts the roller rolling surface on both sides, and both ends in the longitudinal direction extend in the circumferential direction. An extension with a surface facing the roller end face is formed,
In the cross section perpendicular to the bearing circumferential direction of the spacer, a surface of the spacer facing outward in the bearing radial direction is formed to be flush with the extended portion, and from the extended portion to the bearing radial direction of the spacer. Forming the same slope and the same slope toward the inside facing surface,
Rollers characterized in that the flow direction of the resin is orthogonal to the contact line direction with the spacer by providing a single gate on the surface of the spacer facing the inner or outer side in the bearing radial direction. bearing. The roller bearing according to claim 1 or 2, wherein a notch portion is provided on a surface facing the inner side or the outer side in the radial direction of the bearing at a central portion in the longitudinal direction of the spacer . When the circumferential clearance is S, the roller length is Lw, and the maximum length of the extended portion of the spacer is L, the clearance Sa between the extended portion and the end surface of the spacer is within the range of Formula 1. Item 1, 2 or 3 roller bearing.

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