JP2007170436A - Angular ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an angular ball bearing capable of sufficiently supplying lubricating oil to an inner area between two contact points of a ball and a raceway surface. <P>SOLUTION: An oil groove 5 extending in a circumference direction is formed on each raceway surface 1a, 2a between two contact points P<SB>1</SB>, P<SB>2</SB>and Q<SB>1</SB>, Q<SB>2</SB>on which the balls 3 and an inner ring 1 and an outer ring 2 contact. Consequently, lubricating oil can be sufficiently supplied to the inner area between the contact points where clearance is almost eliminated due to elastic contact deformation at each contact point P<SB>1</SB>, P<SB>2</SB>and Q<SB>1</SB>, Q<SB>2</SB>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an angular contact ball bearing.

  Angular ball bearings have raised shoulders on the inner and outer rings on opposite sides of the bearing center line so that they can receive radial and axial loads. It comes in contact with each shoulder side at a biased point. There is almost no rise on the counter portion side opposite to the shoulder portion, and the range of the central angle at which the ball is received by each raceway surface of the inner and outer rings is about 0 to 78 ° from the bearing center line to the shoulder portion side.

  In such an angular ball bearing, which is used at a low speed for a construction machine or a reduction gear of a robot and requires high rigidity, at least one of the raceway surfaces of the inner ring and the outer ring and a ball having a different contact angle 2 There is one in which contact is made at two contact points and the contact load between the ball and the raceway surface is dispersed to reduce the amount of elastic contact deformation (see, for example, Patent Document 1).

JP 2005-201294 A

  As described in Patent Document 1, in an angular contact ball bearing in which at least one of the raceways of the inner ring and the outer ring and the ball are in contact at two contact points having different contact angles, these are caused by elastic contact deformation at each contact point. There is almost no gap between the ball and the raceway surface in the inner region between the contact points, and there is a problem that lubricating oil is difficult to be supplied to the inner region. For this reason, wear tends to occur on the inner region side of each contact point. Further, since the contact area between the ball and the raceway surface is increased, the relative slip between the two is also increased, and the oil film is easily cut.

  Accordingly, an object of the present invention is to provide an angular ball bearing capable of sufficiently supplying lubricating oil to an inner region between two contact points between a ball and a raceway surface.

  In order to solve the above-described problems, the present invention is such that the ball contacts the raceway surfaces of the inner ring and the outer ring on opposite sides of the bearing center line, and contacts at two contact points having different contact angles with at least one of the raceway surfaces. In this angular ball bearing, an oil groove extending in the circumferential direction is formed on the raceway surface between two contact points with which the ball contacts.

  That is, by forming an oil groove extending in the circumferential direction on the raceway surface between two contact points with which the ball contacts, an inner region between the two contact points where there is almost no gap due to elastic contact deformation at each contact point In addition, the lubricating oil can be sufficiently supplied.

  By forming the oil groove in the center between the two contact points, the oil groove does not enter the elastic contact deformation region at each contact point, and edge stress is generated between the ball and the groove edge. Can be prevented.

  Even if the spread angle between the contact angles of the two contact points is set to 25 ° or more, the oil groove does not enter the elastic contact deformation region at each contact point, and an edge is formed between the ball and the groove edge. Generation of stress can be prevented.

  By bringing the ball into contact with both of the raceways of the inner ring and the outer ring at the two contact points having the different contact angles, the bearing rigidity can be further increased.

  In the angular ball bearing of the present invention, the oil groove extending in the circumferential direction is formed on the raceway surface between the two contact points with which the ball contacts, so that the two contacts are almost free of gaps due to elastic contact deformation at each contact point. Lubricating oil can be sufficiently supplied to the inner region between the points, and wear on the inner region side of each contact point can be prevented.

  By forming the oil groove in the center between the two contact points, the oil groove does not enter the elastic contact deformation region at each contact point, and edge stress is generated between the ball and the groove edge. Can be prevented.

  Even if the spread angle between the contact angles of the two contact points is set to 25 ° or more, the oil groove does not enter the elastic contact deformation region at each contact point, and an edge is formed between the ball and the groove edge. Generation of stress can be prevented.

  By bringing the balls into contact with both the inner and outer raceway surfaces at two contact points having different contact angles, the bearing rigidity can be further increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this angular ball bearing, as shown in FIG. 1, a plurality of balls 3 are held by a cage 4 between raceway surfaces 1 a and 2 a of an inner ring 1 and an outer ring 2, and the inner ring 1 and the outer ring 2 pass through a bearing center O. Shoulder portions 1b and 2b swelled on opposite sides of the bearing center line C are provided, and counter portions 1c and 2c are provided on the opposite sides of the raceway surfaces 1a and 2a.

The ball 3 is in contact with the raceway surface 1a of the inner ring 1 at two contact points P ₁ and P ₂ that are offset from the bearing center line C toward the shoulder 1b at contact angles α _P1 and α _P2 , respectively. The contact surface 2a is also in contact at contact angles α _Q1 and α _Q2 at two contact points Q ₁ and Q ₂ that are offset from the bearing center line C toward the shoulder 2b. In this embodiment, the contact angles α _P1 , α _P2 on the inner ring 1 side and the contact angles α _Q1 , α _Q2 on the outer ring 2 side are set to be equally symmetrical with respect to the bearing center O.

The spread angles β _P and β _Q between the contact angles α _P1 and α _{P2 of the} contact points P ₁ and P ₂ and the contact angles α _Q1 and α _{Q2 of the} contact points Q ₁ and Q ₂ are both 30 °. An oil having a circular cross section that is set and extends in the circumferential direction to the raceway surfaces 1a and 2a of the inner ring 1 and the outer ring 2 at the center between the contact points P ₁ and P ₂ and the contact points Q ₁ and Q _2. A groove 5 is formed.

  In the above-described embodiment, the oil groove formed between the two contact points has an arc cross section, but the oil groove may have an arbitrary cross-sectional shape such as a V cross section or each cross section.

  Further, in the above-described embodiment, the raceway surfaces of both the inner ring and the outer ring and the ball are brought into contact at two contact points, and the contact angles at the contact points of both raceway surfaces are set to be equal in point symmetry. These contact angles are not necessarily point-symmetric and set equal. Note that only one of the raceway surfaces of the inner ring and the outer ring may be brought into contact with the ball at two contact points.

Longitudinal sectional view showing an embodiment of the angular ball bearing

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 2 Outer ring 1a, 2a Raceway surface 1b, 2b Shoulder part 1c, 2c Counter part 3 Ball 4 Cage 5 Oil groove

Claims (4)

  In the angular contact ball bearing in which the balls are in contact with the raceway surfaces of the inner ring and the outer ring on opposite sides of the bearing center line and are in contact at two contact points having different contact angles with at least one of the raceway surfaces, An angular ball bearing, wherein an oil groove extending in a circumferential direction is formed on a raceway surface between contact points.   The angular ball bearing according to claim 1, wherein the oil groove is formed at a center between the two contact points.   The angular contact ball bearing according to claim 1 or 2, wherein a spread angle between contact angles of the two contact points is 25 ° or more.   The angular ball bearing according to claim 1, wherein the ball is in contact with both the raceway surfaces of the inner ring and the outer ring at two contact points having the different contact angles.

Images