JP2007162916A - Roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing which makes a spacer interposed between rollers, wherein the shared use of a spacer is allowed among bearings with different roller lengths and the stirring resistance of lubricating oil during an operation of a bearing can be reduced. <P>SOLUTION: A roller bearing is provided with an outer ring 12, an inner ring 14, a plurality of rollers 16 and spacers 18 interposed between adjacent rollers 16. One end of the spacer 18 is provided with: an expanded part 18a having a surface facing an end surface 16b of the roller 16; and a surface 18d facing a collar side surface of a raceway ring (12 or 14). <P>COPYRIGHT: (C)2007,JPO&INPIT

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 rollers instead of a cage. This type of roller bearing can incorporate more rollers in the bearing and can exhibit a high load capacity.

  As shown in FIGS. 8 and 9, the applicant of the present invention, as shown in FIGS. 8 and 9, in the roller bearing in which the spacer is interposed between the adjacent rollers, the extension portion having a surface facing the roller end surface at both axial ends of the spacer. It is proposed to restrict the movement of the spacer in the axial direction (Japanese Patent Application No. 2005-253746). In this case, if the length of the roller to be used changes, it is necessary to manufacture a dedicated spacer according to the length. As the material of the spacer, various synthetic resins and metals such as high-strength brass are used, and the former is generally manufactured by injection molding and the latter is manufactured by casting or cutting. Here, in the production of metal spacers, it is difficult to manage the dimensional accuracy by casting, and it is preferable to manufacture by cutting functionally. However, the cut product is not suitable for mass production, and the complexity of the shape is not good. Together, the cost is very high.

In addition, as shown in FIG. 10, the applicant of the present application has proposed that the movement of the spacer in the axial direction is regulated by supporting the extended portion of the spacer with an annular side plate fixed to the inner ring or the outer ring. (Japanese Patent Application No. 2005-253738). In this case, an extension is provided only at one end of the spacer in the axial direction, and the extension can be supported by the side plate to restrict the movement of the spacer in the axial direction. It can also be used. However, the side plate is expensive to manufacture, and special processing is required for the inner ring or the outer ring to which the side plate is to be fixed, and also causes an increase in the agitation resistance of the lubricating oil during operation of the bearing.
Japanese Patent No. 3549530

  The main object of the present invention is to enable a roller bearing with a spacer between rollers to be used as a spacer in a bearing having a different roller length, and further reduce the agitation resistance of lubricating oil during the operation of the bearing. There is to make it.

  A roller bearing according to the present invention includes an outer ring, an inner ring, a plurality of rollers, and a spacer interposed between adjacent rollers, a surface facing the end face of the roller at one end of the spacer, and a raceway It is characterized in that a surface facing the collar side of the ring is provided. By adopting such a configuration, it becomes possible to share the spacer in the bearings having different roller lengths. That is, the movement of the spacer in the axial direction is regulated in one direction by the roller end face, and the opposite direction is regulated by the outer ring collar side face or the inner ring collar side face. As a result, even if the roller length changes, the spacer can also be used.

  Furthermore, the stirring resistance of the lubricating oil during the operation of the bearing can be reduced. That is, the spacer does not cover the roller rolling surface over a wide area, and the lubricating oil around the roller easily enters and exits, so that the stirring resistance is reduced and the cooling efficiency is improved.

  The shape is also advantageous when the spacer is manufactured by cutting. That is, first, after forming an integrated comb cage, the spacer can be manufactured by cutting off the pillar portion. Although it is unrealistic to apply this method to spacers with extensions at both ends in the axial direction, the comb type cage can easily form the pillar part that becomes the spacer by simple drilling. The spacer can be manufactured at low cost.

  According to a second aspect of the present invention, in the roller bearing of the first aspect, when the roller diameter is Dw, the number of rollers is Z, and the circumferential clearance is S, 0.001 × Dw × Z ≦ S ≦ 0.01 × Dw This is characterized in that the relationship of × Z is established. By adopting such a configuration, it is possible to stabilize the behavior of the spacer and suppress vibration while avoiding disappearance of the circumferential clearance due to thermal expansion of the spacer and the roller during operation of the bearing.

  According to a third aspect of the present invention, in the roller bearing of the first or second aspect, when the maximum value of the length of the expansion portion is L and the roller diameter is Dw, 0.2 × Dw ≦ L ≦ 0.9 × Dw The relationship is established. The reason why the lower limit is set to 0.2 × Dw is to bring the extended portion into contact with the flat portion near the center that avoids chamfering of the end face of the roller. The reason why the upper limit is set to 0.9 × Dw is to prevent the adjacent spacers from interfering with each other in the extended portion.

  According to a fourth aspect of the present invention, in the roller bearing of any one of the first to third aspects, the spacer extends from the inner diameter side to the outer diameter side of the pitch circle of the roller and faces the roller rolling surface of the spacer. The surface has a concave shape for receiving the roller rolling surface. By adopting such a configuration, the movement of the spacer in the radial direction can be restricted only by the roller rolling surface. In other words, it is possible to regulate the movement of the spacer in the radial direction only by pinching the spacer with the rollers without contacting the inner ring or the outer ring.

  According to a fifth aspect of the present invention, in the roller bearing according to any one of the first to fourth aspects, the spacer is guided by an inner surface of the outer ring. According to a sixth aspect of the present invention, in the roller bearing of any one of the first to fourth aspects, the spacer is guided by an inner ring outer diameter surface. As described above, the spacer may only be sandwiched between rollers, but its behavior is further stabilized by guiding it to the inner surface of the outer ring or the outer surface of the inner ring. Here, the “outer ring inner diameter surface” and the “inner ring outer diameter surface” may be any surfaces that can support and guide the spacer in the radial direction. For example, the former refers to the raceway surface of the outer ring and the inner diameter surface of the collar. The latter refers to the raceway surface of the inner ring and the outer diameter surface of the collar.

  According to a seventh aspect of the present invention, in the roller bearing of the fifth aspect, the surface of the spacer facing the inner ring surface of the outer ring is a convex curved surface having a radius of curvature smaller than the radius of curvature of the inner ring surface of the outer ring. It is. By adopting such a configuration, the so-called “wedge film effect (effect in which the fluid is drawn into the wedge-shaped gap narrowing in the movement direction by viscosity to generate pressure, that is, load capacity)” is obtained, and the spacer Heat generation and wear on the guide surface can be reduced. Here, the “outer ring outer diameter surface” may be any surface that can support and guide the spacer in the radial direction, and refers to, for example, the raceway surface and the inner diameter surface of the outer ring.

  According to this invention, in the roller bearing in which the spacer is interposed between the rollers, the spacer can be used in the bearing having a different roller length. Furthermore, since the agitation resistance of the lubricating oil during the operation of the bearing is reduced and the cooling efficiency is improved, a roller bearing having a high allowable rotational speed can be provided.

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

  The embodiment shown in FIG. 1 is an example applied to an NJ type cylindrical roller bearing, and includes an outer ring 12, an inner ring 14, a cylindrical roller 16, and a spacer 18. This cylindrical roller bearing is of the NJ type, the outer ring 12 has a collar 12a on both sides of the raceway, and the inner ring 14 has a collar 14a on one side of the raceway. The cylindrical roller 16 rolls on the raceway surface of the outer ring 12 and the raceway surface of the inner ring 14 on its rolling surface 16a. A spacer 18 is interposed between the adjacent cylindrical rollers 16.

  FIG. 2 shows details of the spacer 18. The spacer 18 is formed with an extended portion 18a having a surface facing the end surface 16b of the roller 16 at one end, and a rising surface 18d facing the inner surface of the collar 12a of the outer ring 12 is formed on the outer diameter side thereof. . When the extended portion 18a comes into contact with the end surface 16b of the roller 16, and the rising surface 18d comes into contact with the inner side surface of the collar 12a of the outer ring 12, the movement of the spacer 18 in the axial direction of the bearing is restricted.

  The spacer 18 has a concave shape in which a surface (hereinafter also referred to as a roller contact surface) 18b facing the rolling surface 16a of the cylindrical roller 16 receives the rolling surface 16a. Here, the roller contact surface 18b is a concave arc having a radius of curvature slightly larger than the radius of curvature of the rolling surface 16a of the cylindrical roller 16, but the concave roller contact surface 18b is formed by a combination of flat surfaces. You can also The roller contact surface 18b extends over the roller pitch circle indicated by the alternate long and short dash line in FIG. 3, that is, from the inner diameter side to the outer diameter side of the roller pitch circle. Therefore, the movement of the spacer 18 in the bearing radial direction is restricted by the rolling surface 16a of the roller 16.

  As shown in FIG. 4, an outer peripheral surface (a surface facing outward in the radial direction when incorporated in the bearing) 18 c of the expansion portion 18 a is a partial cylindrical surface. In other words, the outer peripheral surface of the extended portion 18a is a convex curved surface, and its radius of curvature R1 is smaller than the radius of curvature R2 of the inner peripheral surface of the collar 12a of the outer ring 12. Thereby, during rotation of the bearing, the extended portion 18a of the spacer 18 is guided by the inner peripheral surface of the collar 12a of the outer ring 12, and the behavior of the spacer 18 is stabilized. That is, by supporting the outer peripheral surface 18c of the extended portion 18a of the spacer 18 with the inner peripheral surface of the collar 12a of the outer ring 12, the movement of the spacer 18 in the radial direction is restricted and the behavior is stabilized.

  Further, during the rotation of the bearing, a wedge film effect is generated on the outer peripheral surface 18c of the extended portion 18a of the spacer 18, and heat generation and wear can be reduced. Furthermore, by forming the convex curved surface (18c), edge contact on the outer peripheral surface 18c of the extended portion 18a can be avoided even if the behavior of the spacer 18 is disturbed. In order to avoid edge contact, it is desirable to provide chamfering at the edge of the extended portion 18a facing the bearing circumferential direction.

  In the bearing of this embodiment, as shown in FIG. 6, cylindrical rollers 16 and spacers 18 are alternately arranged on the raceway surface of the outer ring 12, and are positioned on both sides of the cylindrical roller 16 to be incorporated last. By inserting the last cylindrical roller 16 toward the raceway surface of the outer ring 12 in a state where the seat 18 is along the front side of the rolling surface 16a of the arranged cylindrical rollers 16, the spacer 18 on both sides is inserted. The cylindrical roller 16 can be incorporated on the raceway surface of the outer ring 12 while sliding the.

  FIG. 7 shows an example of a process of manufacturing the spacer by cutting. After forming the comb cage, the spacer can be obtained by cutting off the pillar portion by, for example, wire cutting.

If the material of the spacer 18 is 66 nylon (natural) and applied to NJ2324E (φ120 × φ260 × 86), the circumferential clearance S (see FIG. 5) on the pitch circle of the cylindrical roller 16 is 1. It is 5 mm, and is expressed as S = 0.026 × Dw × Z. The minimum thickness of the spacer 18 is 1.8 mm. At this time, even if the temperature of the bearing rises by 100 ° C., the sum of the thermal expansion of the cylindrical roller 16 and the spacer 18 is about 1 mm, and the circumferential clearance S is not crushed. Can withstand the use of Incidentally, the linear expansion coefficient of the cylindrical roller (bearing steel) is 12.5 × 10 ⁻⁶ (° C.), and the linear expansion coefficient of the spacer (66 nylon (N)) is 9 × 10 ⁻⁵ (° C.). Moreover, the maximum value L (see FIG. 3) of the length of the end portion of the spacer 18 expanded in the pitch circle tangential direction is 20 mm, and L = 0.5 × Dw in terms of a mathematical expression. In such a setting, the extended portion 18a contacts the roller end surface 16b near the center beyond the chamfering of the roller 16, and the adjacent spacers 18 do not interfere with each other.

The fracture | rupture perspective view of the cylindrical roller bearing of the state which pulled out the inner ring | wheel which shows embodiment of this invention 1 is a perspective view of the spacer in FIG. Side view of the cylindrical roller bearing of FIG. Partial enlarged view of FIG. 1 is a schematic cross-sectional view of the cylindrical roller bearing of FIG. Sectional drawing which shows the assembly process of the cylindrical roller bearing of FIG. The perspective view which illustrates the manufacturing process of the spacer of FIG. Broken perspective view of cylindrical roller bearing with inner ring removed The perspective view of the spacer in FIG. Broken exploded perspective view of cylindrical roller bearing

Explanation of symbols

12 outer ring 12a collar 14 inner ring 14a collar 16 cylindrical roller 16a rolling surface 16b end face 18 spacer 18a expansion portion 18b roller contact surface 18c convex curved surface 18d rising surface

Claims (7)

  It has an outer ring, an inner ring, a plurality of rollers, and a spacer interposed between adjacent rollers, a surface facing the end surface of the roller at one end of the spacer, and a surface facing the collar side surface of the bearing ring And roller bearings.   The roller bearing according to claim 1, wherein a relationship of 0.001 × Dw × Z ≦ S ≦ 0.01 × Dw × Z is established, where Dw is the roller diameter, Z is the number of rollers, and S is the circumferential clearance.   The roller bearing according to claim 1, wherein a relationship of 0.2 × Dw ≦ L ≦ 0.9 × Dw is established, where L is a maximum value of the length of the extended portion and Dw is a roller diameter.   4. The spacer according to claim 1, wherein the spacer extends from an inner diameter side to an outer diameter side of a pitch circle of the roller, and a surface facing the roller rolling surface of the spacer has a concave shape that receives the roller rolling surface. Roller bearings.   The roller bearing according to claim 1, wherein the spacer is guided by an inner surface of the outer ring.   The roller bearing according to claim 1, wherein the spacer is guided by an outer diameter surface of the inner ring.   The roller bearing according to claim 5, wherein a surface of the spacer facing the inner ring surface of the outer ring is a convex curved surface having a radius of curvature smaller than that of the inner ring surface of the outer ring.

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