JP2007309455A - Ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that heat, torque fluctuation and vibration are caused by the contact of the bearing ring of a ball bearing with a cage. <P>SOLUTION: In the ball bearing of such a type that the bearing ring 12 or 14 is used for guiding the cage 18, rolling contact is made between the cage 18 and the bearing ring 12 or 14 with a rolling element 20 laid between the cage 18 and the bearing ring 12 or 14. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ball bearing.

Usually, a cage of a ball bearing rotates while being guided by a bearing ring or a ball. A guide type in which the cage is guided by the bearing ring is called a bearing ring guide, and may be further distinguished as an inner ring guide and an outer ring guide. The guidance form guided by balls is called rolling element guidance. In the case of a bearing ring guide, the cage and the bearing ring come into contact. For example, the ball bearing shown in FIG. 4 is an inner ring guide, and includes an inner ring 2, an outer ring 4, a ball 6, and a cage 8. Between the outer circumferential surface of the inner ring 2 and the inner circumferential surface of the cage 8. The radial clearance (guide clearance) is controlled to a predetermined value, and the cage 8 is guided by the inner ring 2 while the bearing is rotating. At that time, since the inner ring 2 and the cage 8 are in sliding contact, heat may be generated due to friction. Japanese Utility Model Publication No. 39-34687 describes a technology relating to a ball bearing incorporating a cage for an outer ring guide.
Japanese Utility Model Publication No. 39-34687

  As described above, when the cage is guided by the raceway, since the cage and the raceway are in contact with each other, friction is generated on the contact surface. As a result, heat may be generated, causing a temperature rise. Further, there is a radial clearance (guide clearance) between the race and the cage, and the cage moves in the radial direction by the amount of the guide clearance during rotation. Therefore, problems such as torque fluctuations and vibrations may occur.

  A main object of the present invention is to eliminate problems such as heat generation, torque fluctuation, and vibration caused by contact between a bearing ring of a ball bearing and a cage.

  This invention is a ball bearing of a type in which a cage is guided by a raceway guide, that is, an inner ring or an outer race, and a problem is caused by rolling and contacting the cage and the raceway with a rolling element interposed between the cage and the raceway. Is a solution.

  That is, the ball bearing of the present invention has an inner ring, an outer ring, a ball, and a cage, and is characterized by rolling contact between the cage and the raceway ring that guides the cage.

  According to a second aspect of the present invention, in the ball bearing of the first aspect, a rolling element is interposed between the cage and the raceway ring.

  According to a third aspect of the present invention, in the ball bearing of the second aspect, the cage is provided with an accommodating portion for the rolling element.

  According to the present invention, since the raceway and the cage are brought into rolling contact with each other, the friction is greatly reduced as compared with the conventional sliding contact, so heat generation is reduced. Further, since the rotation of the cage is stable, torque fluctuation and vibration can be prevented or suppressed.

  FIG. 1 shows an embodiment of the present invention. The ball bearing according to this embodiment includes an inner ring 12, an outer ring 14, a ball 16, and a cage 18, and a rolling element 20 is interposed between the inner ring 12 and the cage 18. Here, the same ten rolling elements 20 as the balls 16 are arranged, and one rolling element 20 is located between the adjacent balls 16 and the balls 16. Each rolling element 20 is accommodated in a recess 22 formed on the inner peripheral surface of the cage 18.

  The number of rolling elements 20 is desirably three or more, and considering the stability of the cage rotation, it is desirable to arrange them at equal intervals. Moreover, the recessed part 22 as an accommodating part of the rolling element 20 may be provided in the holder | retainer 18 like the above-mentioned example, or may be provided in a bearing ring (inner wheel 12 in the above-mentioned embodiment). When the concave portion 22 is provided in the cage 18, the bearing ring is advantageous in that a conventional standard bearing can be used as it is.

  As described above, by rolling the rolling element between the cage and the raceway and rolling it, the friction can be reduced and the rotation of the cage can be stabilized. Further, since the rolling elements are interposed between the guide surfaces of the cage and the raceway, the raceway and the cage are in point contact with each other, so that the radial clearance is reduced and the rotation of the cage is stabilized. Furthermore, it is effective against torque fluctuations and vibrations. By interposing the rolling elements, a space is created between the cage and the race. Therefore, it is useful for holding the grease or the oil permeability is improved in the case of oil lubrication, and the lubricity is improved in any case.

  FIG. 2 shows a modification. 2A corresponds to an enlarged view of FIG. 1A, and FIG. 2B shows a modification thereof. In FIG. 1A, rolling elements (balls) 20 are accommodated in the recesses 22 provided on the inner peripheral surface of the cage 18, and roll on the outer peripheral surface of the inner ring 12. On the other hand, in FIG. 1B, a track 24 for the rolling elements (balls) 20 is provided on the outer peripheral surface of the inner ring 12. The track 24 has a semicircular cross section and is formed on the outer circumferential surface of the inner ring 12 over the entire circumference. When the track 24 is provided, an effect of restricting the movement of the cage 20 in the axial direction can be obtained, which helps prevent vibration and further stabilizes the rotation of the cage.

  The modification shown in FIG. 3 corresponds to an example in which the rolling elements 20 in FIG. 2 are replaced with balls. In the case of FIG. 3 (A), the outer peripheral surface of the inner ring 12 becomes the rolling surface of the rolling element (roller) 20 as in FIG. 2 (A). In the case of FIG. 3 (B), a track 26 for the rolling elements (rollers) 20 is provided on the outer peripheral surface of the inner ring 12 as in FIG. 2 (B). The track 26 has a rectangular cross section and is formed on the outer peripheral surface of the inner ring 12 over the entire circumference. When the track 26 is provided, an effect of restricting the axial movement of the cage 20 can be obtained, which helps prevent vibration and further stabilizes the rotation of the cage.

(A) is an axial sectional view of a ball bearing showing an embodiment of the present invention, and (B) is an axial perpendicular sectional view. Sectional drawing similar to FIG. 1 (A) which shows the modification in case a rolling element is a ball Longitudinal sectional view similar to FIG. 1 (A) showing a modification when the rolling element is a roller Axial sectional view of ball bearing showing conventional technology

Explanation of symbols

12 Inner ring 14 Outer ring 16 Ball 18 Cage 20 Rolling element (ball or roller)
22 Concave part (rolling element housing part)
24 Tracks for rolling elements (balls) 26 Tracks for rolling elements (rollers)

Claims (3)

  A ball bearing having an inner ring, an outer ring, a ball, and a cage, in which the cage and a raceway that guides the cage are brought into rolling contact. The ball bearing according to claim 1, wherein a rolling element is interposed between the cage and the race. The ball bearing according to claim 2, wherein the cage is provided with a housing portion for the rolling elements.

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