JP2007198501A - Double-row angular ball bearing for axle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-row angular ball bearing for an axle capable of reducing torque during linear advancement of a vehicle and preventing riding up on a shoulder during cornering. <P>SOLUTION: The radius of curvature of a raceway groove 21 of an outer ring 11 is set between 50.5% and 52.0% of a ball diameter at a central part with a plane surface in the radial direction including an inflection point β1 as the boundary and between 55% and 65% of the ball diameter on the end side. Further, the radius of curvature of a raceway groove 31 of an inner ring 12 is set between 55% and 65% of the ball diameter at a central part with a plane surface in the radial direction including an inflection point β2 as the boundary and between 50.5% and 52.0% of the ball diameter on the end side. During linear advancement of the vehicle, the position of a ball 13 is set so that the ball 13 contacts parts of raceway grooves with a small curvature of the inner and outer rings 11, 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an axle double row angular contact ball bearing.

  Conventionally, as a double row angular contact ball bearing for an axle, there is one described in Utility Model Registration No. 2577108 (Patent Document 1). The double-row angular contact ball bearing for an axle includes an outer ring and an inner ring. Between the two rows of raceway grooves provided on the inner peripheral surface of the outer ring and the two rows of raceway grooves provided on the outer peripheral surface of the inner ring. A plurality of balls are arranged. The curvature of the outer ring and the inner ring raceway groove of the double-row angular contact ball bearing for the axle is a single curvature. The axle double row angular contact ball bearing supports a wheel that rotates together with the axle so as to be rotatable with respect to the vehicle body side member.

  However, in the conventional double-row angular contact ball bearing for an axle, since the curvature of the inner ring and the outer ring is single, if this single curvature is reduced, the contact ellipse between the ball and the raceway groove is small. However, there is an advantage that the torque at the time of straight traveling is reduced and the fuel consumption of the vehicle is reduced, but there is a drawback in that so-called shoulder climbing occurs because the ball is detached from the track groove during cornering.

On the other hand, increasing the single curvature of the track groove has the advantage of preventing shoulder climbing during cornering, but the contact ellipse between the ball and the track groove during straight travel increases, so the torque increases. As a result, there is a disadvantage that the fuel consumption is deteriorated.
Utility Model Registration No. 2577108

  SUMMARY OF THE INVENTION An object of the present invention is to provide a double-row angular contact ball bearing for an axle that can reduce the torque when the vehicle is traveling straight and can prevent the shoulder from climbing during cornering.

In order to achieve the above object, the double-row angular contact ball bearing for an axle of the present invention is:
Arranged between the outer ring provided with two rows of raceway grooves on the inner peripheral surface, the inner ring provided with two rows of raceway grooves on the outer peripheral surface and the raceway grooves facing each other so as to face the raceway grooves of the outer ring. In a double row angular contact ball bearing for an axle comprising
The curvature of the raceway groove of the outer ring is a composite curvature with a small curvature on the end side in the axial direction and a large curvature on the central side in the axial direction,
In addition, the curvature of the raceway groove of the inner ring is a composite curvature having a large curvature on the end portion side in the axial direction and a small curvature on the central portion side in the axial direction.

  In this specification, the raceway groove is defined as a region where the ball travels during straight travel and cornering, and the raceway groove does not include a cylindrical surface or the like on the center portion of the bearing where the ball does not travel.

  According to the double-row angular contact ball bearing for an axle of the present invention, the curvature on the axial end side of the raceway groove of the outer ring is reduced and the curvature on the center side in the axial direction of the raceway groove of the inner ring is reduced. Therefore, by setting the position of the ball so that the ball comes into contact with the raceway groove portion having a small curvature of the outer ring and the inner ring during straight running, which occupies most of the driving time, the ball and the raceway groove during straight running The contact ellipse can be reduced, and the frictional force generated between the ball and the raceway groove when traveling straight can be reduced. Therefore, it is possible to reduce the torque when traveling straight, and to significantly reduce the fuel consumption of the vehicle.

  Further, according to the double-row angular contact ball bearing for an axle of the present invention, the curvature of the center portion in the axial direction of the raceway groove of the outer ring is increased and the curvature of the end portion in the axial direction of the raceway groove of the inner ring is increased. Since the ball has been enlarged, even if the ball moves to the center part side in the axial direction of the raceway groove of the outer ring and the end side in the axial direction of the raceway groove of the inner ring during cornering of the vehicle, Can be held in the raceway groove part with a large curvature. Therefore, when the vehicle is cornered, the ball does not ride on the shoulder.

  Moreover, the double-row angular contact ball bearing for an axle of one embodiment is characterized in that the ball is made of ceramic.

  According to the double-row angular contact ball bearing for an axle of the above embodiment, since the ball is made of ceramic, the rigidity of the ball can be made higher than that of steel, and the contact ellipse between the ball and the raceway groove can be made small. Therefore, even if the preload varies in a state where the balls are incorporated, the balls can be reliably brought into contact with the portion where the curvature of the raceway groove is small when the vehicle is traveling straight, so that the torque during straight traveling can be ensured. This can reduce the fuel consumption.

  According to the double-row angular contact ball bearing for an axle of the present invention, the curvature on the axial end side of the raceway groove of the outer ring is reduced and the curvature on the center side in the axial direction of the raceway groove of the inner ring is reduced. Therefore, the contact ellipse between the ball and the raceway groove can be made small when going straight, by setting the ball so as to be in contact with the raceway groove portion where the curvature of the outer ring and the inner race is small when going straight, which occupies most of the driving. Therefore, it is possible to reduce the torque when traveling straight, and to significantly reduce the fuel consumption of the vehicle.

  Further, according to the double-row angular contact ball bearing for an axle of the present invention, the curvature of the center portion in the axial direction of the raceway groove of the outer ring is increased and the curvature of the end portion in the axial direction of the raceway groove of the inner ring is increased. Since the ball has been enlarged, even if the ball moves to the center part side in the axial direction of the raceway groove of the outer ring and the end side in the axial direction of the raceway groove of the inner ring during cornering of the vehicle, Can be held in the raceway groove portion with a large curvature, so that it is possible to prevent the ball from climbing up when cornering the vehicle.

  Also, according to the double-row angular contact ball bearing for an axle according to one embodiment, since the ball is made of ceramic, the rigidity of the ball can be made higher than that of the steel ball, and the contact ellipse between the ball and the raceway groove can be reduced. it can. Therefore, when the vehicle is traveling straight, the ball can be brought into contact with the raceway groove portion where the curvature of the inner and outer rings is small, the torque when traveling straight can be reliably reduced, and the fuel consumption can be reliably reduced.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 is a sectional view in the axial direction of a double row angular contact ball bearing for an axle according to an embodiment of the present invention. The double-row angular contact ball bearing for an axle includes an outer ring 11 and an inner ring 12, two rows of race grooves 21 and 22 provided on the inner peripheral surface of the outer ring 11, and a race groove of the outer ring 11 on the outer peripheral surface of the inner ring 12. A plurality of ceramic balls 13 held by the retainer 14 are arranged between the two rows of raceway grooves 31 and 32 provided at opposing positions 21 and 22. The two raceway grooves 21 and 22 on the inner peripheral surface of the outer ring 11 and the two raceway grooves 31 and 32 on the outer peripheral surface of the inner ring 12 are formed substantially symmetrically.

  The outer ring 11 is fitted or connected to a vehicle body side member of the vehicle, and the inner ring 12 is fitted to an outer diameter portion of a driving wheel axle of the vehicle via a hub wheel (not shown).

  A seal member 15 is disposed between the inner peripheral surface of the outer ring 11 and the outer peripheral surface of the inner ring 12 at both ends in the axial direction. The seal member 15 seals the raceway grooves 21, 22, 31, 32 and balls 13 of the outer ring 11 and the inner ring 12 to the outside.

  FIG. 2 shows the positional relationship between the ball 13 of the double-row angular contact ball bearing for an axle and the raceway grooves 21 and 31 of the inner and outer rings 11 and 12 when the vehicle is traveling straight.

  A line segment A shown in FIG. 2 is a straight line extending in the radial direction through the center of the ball 13, and a line segment B is a contact line between the ball 13 and the inner and outer rings 11, 12.

  2 is an inflection point at which the curvature of the raceway groove 21 of the outer ring 11 changes in the cross-sectional view of FIG. The raceway groove 21 of the outer ring 11 has a radius of curvature on the center side with respect to a radial plane including β1 as 50.5% to 52.0% (preferably 51.0%) of the ball diameter of the ball 13. % To 51.5%), and the radius of curvature on the end side is set between 55% and 65% of the ball diameter of the ball 13 (preferably 59.75% to 60.25%). Has been. A line segment C shown in FIG. 2 is a straight line connecting the inflection point β1 and the center of curvature of the raceway groove portion having a small curvature on the end side in the axial direction of the outer ring 11, and the line segment C is the line segment A. Is set to a larger angle than the contact angle indicated by θ3 in FIG. In this embodiment, θ1 is set to approximately 31 °, and θ3 is set to an angle between 29 ° and 30 °.

  On the other hand, β2 shown in FIG. 2 is an inflection point where the curvature of the raceway groove 31 of the inner ring 12 changes in the cross-sectional view of FIG. The raceway groove 31 of the inner ring 12 has a radius of curvature on the center portion side of a radial plane including β2 that is 55% to 65% of the ball diameter of the ball 13 (preferably 59.75% to 60.60). 25%), and the radius of curvature of the raceway groove portion on the end side is 50.5% to 52.0% (preferably 51.0% to 51.5%) of the ball diameter of the ball 13 Is set between. A line segment D shown in FIG. 2 is a straight line connecting the inflection point β2 and the center of curvature of the raceway groove portion having a small curvature on the center side in the axial direction of the inner ring 12, and the line segment D is the line segment A. Is set to approximately 31 °.

  Since the contact angle θ3 is set between 29 ° and 30 °, as shown in FIG. 2, the ball 13 has a curvature of the raceway grooves 31 and 21 of the inner and outer rings 11 and 12 when the vehicle goes straight. Is in contact with the small raceway groove. The set of β1 and β2 in the three-dimensional space is a single circumference extending in the circumferential direction.

  In the double-row angular contact ball bearing for an axle of the above embodiment, the radius of curvature of the raceway groove portion with the smaller curvature is changed from 55% to 65% of the ball diameter, but the radius of curvature of the raceway groove portion with the smaller curvature is changed. It has been experimentally known that if the diameter is smaller than 55% of the ball diameter, the effect of reducing the torque when the vehicle goes straight is lost. Further, if the radius of curvature of the raceway groove portion having the smaller curvature is larger than 65% of the ball diameter, the contact ellipse between the ball and the raceway groove becomes very small, and the surface pressure between the ball and the raceway groove is reduced. Becomes excessive, and the raceway groove is frequently peeled off.

  According to the double-row angular contact ball bearing for the axle of the above embodiment, the curvature of the end portions in the axial direction of the raceway grooves 21 and 22 of the outer ring 11 is reduced, and the center of the raceway grooves 31 and 32 of the inner race 12 in the axial direction. Since the curvature of the portion side is reduced and the ball 13 contacts the raceway groove portion where the curvature of the inner and outer rings 11, 12 is small when the vehicle goes straight, the ball 13 and the inner and outer rings 11, 12 move straight. The contact ellipse with the raceway grooves 21, 31 and 22, 32 becomes smaller, and the frictional force generated between the ball 13 and the raceway grooves 21, 31 and 22, 32 of the inner and outer rings 11, 12 becomes smaller when going straight. . Therefore, it is possible to reduce the torque when traveling straight, and to significantly reduce the fuel consumption of the vehicle.

  Further, according to the double-row angular contact ball bearing for an axle of the above embodiment, the curvature of the center portion side in the axial direction of the raceway grooves 21 and 22 of the outer ring 11 is increased and the axial direction of the raceway grooves 31 and 32 of the inner race 12 is increased. Since the curvature on the end side of the inner ring 12 is increased, the ball 13 is positioned at the axially central side of the raceway grooves 21 and 22 of the outer ring 11 and the end portions in the axial direction of the raceway grooves 31 and 32 of the inner ring 12 when cornering the vehicle. Even if it moves to the side, the moved ball 13 can be held by the raceway groove portion where the curvature of the outer ring 11 and the inner ring 12 is large. Therefore, when the vehicle is cornered, the ball 13 does not ride on the shoulder.

  Further, according to the double row angular contact ball bearing for an axle of the above embodiment, since the ball 13 is made of ceramic, the rigidity of the ball 13 is increased, and the contact between the ball 13 and the raceway grooves 21, 22, 31, 32 is increased. The ellipse is smaller than when using steel balls. Therefore, due to the variation in the preload in the state where the ball is incorporated, the size of the negative gap between the inner and outer rings 11, 12 and the ball 13 varies, and the contact position of the ball 13 when it goes straight is a predetermined position. Even if it moves toward the raceway groove portion with a larger curvature, the contact ellipse between the ball 13 and the raceway grooves 21, 22, 31, and 32 has a large curvature and a small portion with respect to the raceway grooves 21, 22, 31, and 32. The ball 13 can be reliably brought into contact with the portion having the small curvature of the raceway grooves 21, 22, 31, 32 when the vehicle goes straight without intervening. Therefore, it is possible to reliably reduce the torque when traveling straight, and to reliably reduce fuel consumption.

  In the double-row angular contact ball bearing for an axle according to the above embodiment, θ1 which is an angle formed by the line segment C that determines the position of the inflection point β1 in the cross-sectional view in the axial direction and the cross-sectional view in the axial direction. The angle θ2 that is the angle formed by the line segment D that determines the position of the inflection point β2 with the line segment A is set to approximately 31 °. However, the values of θ1 and θ2 are not limited to 31 °. θ1 and θ2 may be set to any angle. Further, it is not necessary that θ1 and θ2 be the same angle.

  Moreover, in the double row angular contact ball bearing for axles of the said embodiment, the ceramic ball | bowl 13 was employ | adopted, However, You may employ | adopt steel balls in the double row angular contact ball bearing for axles of this embodiment.

  In the double-row angular contact ball bearing for an axle according to the above-described embodiment, the inflection points .beta.1 and .beta.1 are formed at the inner and outer rings 11 and 12, respectively, in the raceway grooves 21, 22, 31, and 32 of the inner and outer rings 11 and 12 in the axial sectional view. β2 is formed one by one, and in the inner ring 12, the curvature on the axial end portion of the raceway grooves 31 and 32 is increased with the radial plane including β2 as a boundary, and the central portion in the axial direction is also formed. In the outer ring 11, the curvature on the axial end portion of the raceway grooves 21 and 22 is reduced with the radial plane including β 1 as the boundary, and the axial center portion side of the outer ring 11 is also reduced. In the double-row angular contact ball bearing for an axle of the present invention, the curvature on the axial end portion of the inner ring raceway groove is large, the curvature on the central portion side in the axial direction is small, and the outer ring raceway The curvature on the axial end side of the groove is small and the curvature on the central side in the axial direction is large. If the inner and outer ring raceway grooves satisfy the above condition, three or more inflection points may be provided in the inner and outer ring raceway grooves in the axial cross section.

It is sectional drawing of the axial direction of the double row angular contact ball bearing for axles of one Embodiment of this invention. It is the elements on larger scale of the said sectional view.

Explanation of symbols

11 Inner ring 12 Outer ring 13 Ball 21, 22, 31, 32 Track groove

Claims (2)

Arranged between the outer ring provided with two rows of raceway grooves on the inner peripheral surface, the inner ring provided with two rows of raceway grooves on the outer peripheral surface and the raceway grooves facing each other so as to face the raceway grooves of the outer ring. In a double row angular contact ball bearing for an axle comprising
The curvature of the raceway groove of the outer ring is a composite curvature with a small curvature on the end side in the axial direction and a large curvature on the central side in the axial direction,
In addition, the curvature of the raceway groove of the inner ring is a compound curvature with a large curvature on the end portion side in the axial direction and a small curvature on the central portion side in the axial direction. . In the double row angular contact ball bearing for axles according to claim 1,
A double row angular contact ball bearing for an axle, wherein the ball is made of ceramic.

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