JP4251332B2 - Wheel bearing device - Google Patents

Description

  The present invention relates to a wheel bearing device in an automobile.

  2. Description of the Related Art Double-row angular contact ball bearings are generally used in automobile wheel bearing devices. FIG. 8A shows a partial cross-sectional view of an example thereof. The raceway surfaces 24 and 25 of the outer ring 21 and the inner ring 22 are provided with chamfered portions 24a and 25a having an arcuate cross section at the edges to reduce the edge load of the load surface pressure.

  When a moment load is applied to this bearing, as shown in FIG. 8 (B), the contact angle θ increases, and the contact positions p and q between the raceway surfaces 24 and 25 and the ball 23 are the bearings in the outer ring 21. The inner ring 22 moves outward in the axial direction. At the ball contact positions p and q of the raceway surfaces 24 and 25, an elliptical load surface pressure acting portion around the positions p and q, that is, a contact ellipse (not shown) is generated. When the moment load is large, the contact ellipse may protrude to the chamfered portions 24a and 25a. As a result, an edge load occurs and early peeling occurs. When the chamfered portions 24a and 25a are provided, the increase in the edge load is reduced as compared with the case where the contact ellipse extends from the raceway surfaces 24 and 25 to the cylindrical surface portion of the shoulder without being provided. However, the chamfered portions 24a and 25a cannot perform satisfactory reduction, and it is difficult to eliminate early peeling.

  As a countermeasure, the inner diameter of the outer ring 21 is reduced or the outer diameter of the inner ring 22 is increased as indicated by a two-dot chain line in FIG. 8B so that the contact ellipse does not protrude from the chamfered portions 24a and 25a. It is possible. However, when the inner diameter or the outer diameter is changed in this way, when grinding the raceway surfaces 24 and 25, if a general-purpose grindstone having a cross-sectional shape corresponding to the shape of the groove cross-section is generally used, The vicinity of the portions 24a and 25a approaches the state of machining on the side surface of the grindstone, and the pressing force in the cutting direction of the grindstone hardly acts on this portion. Therefore, the processing time is remarkably increased. In other words, the processing cycle time becomes longer.

  An object of the present invention is to provide a wheel bearing device that can alleviate the generation of edge load due to a contact ellipse when the moment load increases and can avoid an increase in the grinding time of the raceway surface.

The vehicle bearing device of the present invention includes an outer member having a double-row arc-shaped raceway surface on the inner periphery, an inner member having an arc-shaped raceway surface facing each of the raceway surfaces, and the above-described multiple members. and a ball double row interposed between the rows of raceways, the bearing portion of each row wheel bearing device having a contact angle, per the outer member, in the cross section of the raceway surface of the upper Symbol least one column The radial position of the higher shoulder is extended to approximately the center position of the ball, and an auxiliary track surface is provided at the edge of the track surface that is the side of the higher shoulder, and the auxiliary track surface is connected to the track surface. abbreviation sectional smoothly come continue from arc-shaped curve that constitutes the, with a sectional shape composed of small curve or straight curvature than the curve, the form-grinding wheel having a cross-sectional shape of the raceway surface of the outer member it was ground processed surface by cut radially And features. You may provide the chamfering part following the edge part of this auxiliary track surface.
When the auxiliary raceway surface is provided in this way, the contact ellipse protrudes from the raceway surface to the auxiliary raceway surface when a large moment load is applied to the bearing and the contact angle increases. This auxiliary track surface has a cross-sectional shape consisting of a curve or a straight line that smoothly follows the arc-shaped curve constituting the cross section of the track surface and has a smaller curvature than the above curve, so that the contact ellipse protrudes from the auxiliary track surface. However, the occurrence of edge loading is prevented. Further, the auxiliary raceway surface is composed of a curve or a straight line having a smaller curvature than the arcuate curve constituting the cross section of the raceway surface, so that the inner diameter of the outer member is set smaller or the outer diameter of the inner member is set larger. However, since the inclination is larger than the surface obtained by extending the raceway surface as it is, a certain inclination angle can be secured, and when grinding is performed, the side surface of the grindstone is not processed. Therefore, an increase in the processing time of grinding can be avoided. Therefore, the inner diameter of the outer ring and the outer diameter of the inner ring can be set regardless of the grinding limit.

In the present invention, a wheel mounting flange may be provided on one of the outer member and the inner member. Moreover, you may provide the flange for attaching to a vehicle body in any one of the said outer member and inner member. Further, the inner member is composed of an integral hub wheel having a wheel mounting flange and a separate inner ring component member fitted to the outer diameter of the end of the hub wheel. It is good also as what has each track surface of each above-mentioned row.
In various types of wheel bearing devices using the wheel mounting flange, the vehicle body mounting flange, or the inner member composed of the hub wheel and the inner ring component member, the moment load increases due to the provision of the auxiliary track surface in the present invention. The effect of mitigating the occurrence of edge load due to the contact ellipse at the time and the effect of avoiding an increase in the grinding time of the raceway surface can be obtained.

The wheel bearing device of the present invention includes an outer member having a double-row arc-shaped raceway surface on an inner periphery, an inner member having an arc-shaped raceway surface facing each of the raceway surfaces, and the above-described multiple members. and a ball double row interposed between the rows of raceways, the bearing portion of each column Te wheel bearing apparatus odor having a contact angle, per the outer member, the cross-section of the upper Symbol least one raceway surface of the column The radial position of the higher shoulder of the ball is extended to approximately the center position of the ball, and an auxiliary track surface is provided at the edge of the track surface that is the side of the higher shoulder, and the auxiliary track surface is connected to the track. smoothly come continue from arc-shaped curve that constitutes the cross-section of the surface, with the cross-sectional shape composed of small curve or straight curvature than the curve, the form-grinding wheel having a cross-sectional shape of the raceway surface of the outer member Because the surface was cut by cutting in the almost radial direction. It can alleviate the occurrence of an edge load due to contact ellipse at moment load increases, and can avoid an increase in grinding time of the raceway surface.

  A first embodiment of the present invention will be described with reference to FIGS. This embodiment is an example applied to a first-generation inner ring rotation type wheel bearing device. The wheel bearing device includes an outer member 1 having double-row cross-sectional arc-shaped raceway surfaces 4 and 4 on the inner periphery, and cross-section arc-shaped raceway surfaces 5 and 5 respectively facing the raceway surfaces 4 and 4. The inner member 2 is provided, and the double row balls 3 interposed between the double row raceway surfaces 4 and 5 are provided. This wheel bearing device is a double row angular contact ball bearing, and the raceway surfaces 4 and 5 are formed so that the contact angle θ is aligned with the back surface. The contact angle θ is, for example, in the range of 10 to 45 degrees. The outer member 1 is a member on the fixed side, and is composed of a single bearing outer ring. The inner member 2 is a member on the rotation side, and is formed of a split type in which two bearing inner rings 2A are arranged in the axial direction. The balls 3 are held by the cage 6 for each row. The annular spaces at both ends between the inner and outer members 2 and 1 are sealed with seals 7 and 7A.

As shown in an enlarged cross-sectional view in FIG. 2, the radial positions of the higher shoulders c1 and c2 in the cross section of the raceway surfaces 4 and 5 are extended substantially to the center position O of the ball , and the higher shoulders c1 and c2 are extended. Auxiliary track surfaces 4aa and 5aa are provided on the edge portions 4a and 5a of the track surfaces 4 and 5 serving as side portions of c2. The auxiliary raceways 4aa, 5aa is arcuate curve a that constitute the cross section of the raceway surfaces 4 and 5 smoothly continued from b, that have a cross-sectional shape composed of straight lines. This Kodewa auxiliary raceways 4aa, the cross-sectional shape of the 5aa is that is a straight line which becomes the curve a, the tangent of b. The radial position of the edge on the shoulders c1 and c2 side of the auxiliary track surfaces 4aa and 5aa is substantially the center position O of the ball 3. Also, the each raceway surfaces 4 and 5, the auxiliary raceway surface 4aa, chamfer 4ab arcuate cross-sectional shape following the edge of 5aa, 5ab are formed.

According to the bearing device having this configuration, since the auxiliary raceway surfaces 4aa and 5aa are provided, when a large moment load is applied to the bearing and the contact angle θ increases, the contact ellipse (not shown) is separated from the raceway surfaces 4 and 5. It protrudes to the auxiliary track surfaces 4aa and 5aa. However, since the auxiliary track surfaces 4aa and 5aa smoothly follow the curves a and b constituting the cross section of the track surfaces 4 and 5 and have a cross-sectional shape consisting of straight lines, the contact ellipse is formed on the auxiliary track surfaces 4aa and 5aa. Even if it protrudes, edge loading does not occur.
Further, since the auxiliary track surfaces 4aa and 5aa are straight, even if the inner diameter of the outer member 1 is set to be small or the outer diameter of the inner member 2 is set to be large, the track surfaces 4 of the arcuate curves a and b are set. The inclination is larger than the surface obtained by extending 5 as it is, and a certain inclination angle can be secured. Therefore, the auxiliary track surfaces 4aa and 5aa are not in a state of being processed on the side surface of the grindstone when grinding. For this reason, an increase in the processing time of the grinding process can be avoided. Therefore, the inner diameter of the outer member 1 and the outer diameter of the inner member 2 can be set regardless of the grinding limit.

Further, the inner diameter of the outer member 1 is reduced and the inner member 2 is set so that the radial position of the higher shoulders c1 and c2 in the cross section of the raceway surfaces 4 and 5 is substantially the center position O of the ball 3. Since the outer diameter of the contact ellipse is increased, the contact ellipse does not protrude to the chamfered portions 4ab and 5ab, and edge loading does not occur.
Further, since each of the raceway surfaces 4 and 5 is formed with chamfered portions 4ab and 5ab having an arcuate cross section following the edges of the auxiliary raceway surfaces 4aa and 5aa, the edge load of the contact ellipse is further alleviated. . That is, basically, the auxiliary track surfaces 4aa and 5aa can be covered only. However, even when a larger moment load is applied and the contact angle θ increases, the edge load is reduced by the chamfered portions 4ab and 5ab.

  The cross-sectional shapes of the auxiliary track surfaces 4aa and 5aa in the track surfaces 4 and 5 may be curved lines instead of the straight lines. In that case, it is set as a curve with a smaller curvature than the circular-arc-shaped curves a and b which comprise the cross section of the track surfaces 4 and 5. FIG. Also in this case, the generation of the edge load of the contact ellipse can be prevented, and the processing time does not increase in the grinding processing of the raceway surfaces 4 and 5.

3 to 7 show other embodiments of the present invention. A common configuration of each of these embodiments will be described. Each of these embodiments also faces the outer member 1 having double-row (two rows here) raceway surfaces 4 and 4 on the inner periphery, and these raceway surfaces 4 and 4, respectively, as in the first embodiment. A wheel bearing device that includes an inner member 2 having raceway surfaces 5 and 5 and a double row of balls 3 interposed between the raceway surfaces 4 and 5 and rotatably supports the wheel with respect to the vehicle body. ing. The wheel bearing device is a double-row angular contact ball bearing, and the raceway surfaces 4 and 5 are formed so that the contact angles are back to back. The shape of each raceway surface 4, 5 is the same as that described in the first embodiment, and the radial positions of the higher shoulders c 1, c 2 in the cross section of the raceway surfaces 4, 5 are approximately the center position of the ball. The auxiliary track surfaces 4aa and 5aa are provided at the edge portions 4a and 5a of the track surfaces 4 and 5 which are extended to O and the side portions of the higher shoulders c1 and c2. These auxiliary raceway surfaces 4aa and 5aa smoothly follow the arcuate curves a and b (FIG. 2) constituting the cross section of the raceway surfaces 4 and 5, and are from curves or straight lines having a smaller curvature than the curves a and b. It made the cross-sectional shape that have a. The radial position of the edge on the shoulders c1 and c2 side of the auxiliary track surfaces 4aa and 5aa is substantially the center position O of the ball 3. Ball Lumpur 3 is retained by a retainer 6 employed for each row, also on both sides of the open end of the annular space formed between the inner and outer members 2 and 1 are sealed with each sealing 7, 7A, first This is the same as the first embodiment.

FIG. 3 shows a second embodiment of the present invention. This wheel bearing device is a second-generation outer ring rotation type and is a wheel bearing device for supporting a driven wheel.
In the case of this embodiment, the outer member 1 has a wheel mounting flange 1a at one end on the front side, and the wheel is attached to the wheel mounting flange 1a with bolts 14. The inner member 2 is of a split type in which two bearing inner rings 2A are arranged in the axial direction.

FIG. 4 shows a third embodiment of the present invention. This wheel bearing device is a second-generation inner ring rotation type and is a wheel bearing device for driving wheel support.
In the case of this embodiment, the outer member 1 has a vehicle body attachment flange 1b, and is attached to a knuckle or the like of the vehicle body via the vehicle body attachment flange 1b. Other configurations are the same as those of the first embodiment shown in FIGS.

FIG. 5 shows a fourth embodiment of the present invention. This wheel bearing device is a third-generation inner ring rotating type and is a wheel bearing device for supporting a driven wheel.
In the case of this embodiment, the outer member 1 is an integral member having a vehicle body mounting flange 1b. The inner member 2 includes a hub wheel 2B and a separate inner ring member 2C fitted to the outer diameter of the end of the hub wheel 2B. The inner ring member 2C has a raceway surface in each row on the hub wheel 2B and the inner ring member 2C. 5, 5 are formed. The inner ring constituent member 2C is fastened and fixed to the hub wheel 2B in the axial direction by a caulking portion provided on the hub wheel 2B. The inner member 2 has a wheel mounting flange 2a.

FIG. 6 shows a fifth embodiment of the present invention. This wheel bearing device is a third generation inner ring rotating type and is a wheel bearing device for driving wheel support.
In the case of this embodiment, because it is for a drive wheel, in the fourth embodiment shown in FIG. 5, a constant velocity joint (not shown) is connected to the hub wheel 2B that forms the inner member 2 with the inner ring component 2C. An inner diameter hole 2c is formed through which the shaft portion is inserted and fixed. Other configurations are the same as those of the fourth embodiment shown in FIG.

FIG. 7 shows a sixth embodiment of the present invention. This wheel bearing device is a fourth generation bearing device.
In the case of this embodiment, the inner member 2 is a combination of a hub wheel 2B integrally having a wheel mounting flange 2a and another inner ring component 2D. Each row of raceway surfaces 5 and 5 is formed on the hub wheel 2B and the internal component member 2D. The inner ring constituting member 2D is a member in which the outer ring 8a of the constant velocity joint 8 is integrally formed, and a drive shaft (not shown) is connected to the inner ring (not shown) of the constant velocity joint 8. A shaft portion 9 extending integrally from the constant velocity joint outer ring 8a is formed of a large-diameter portion 9a on the base end side and a small-diameter portion 9b that continues to the large-diameter portion 9a through a step, and a hub is formed on the outer periphery of the small-diameter portion 9b. The wheel 2B is fitted. The hub wheel 2B and the inner ring component 2D are integrally fixed by plastic coupling such as caulking. The fact that the outer member 1 has the vehicle body mounting flange 1b is the same as in the case of the embodiment of FIGS.

In the embodiments shown in FIGS. 3 to 7, as in the first embodiment , the radial positions of the higher shoulders c <b> 1 and c <b> 2 in the cross section of the raceway surfaces 4 and 5 are substantially the center positions of the balls 3. O and the fact, auxiliary raceway surface 4aa, to obtain a generation relieving effect of the edge load due to contact ellipse at moment load increase due to the provision, and the effect of the increase in the avoidance of grinding time raceways 4, 5 5aa Can do.

It is sectional drawing of the wheel bearing apparatus concerning 1st Embodiment of this invention. It is a principal part expanded sectional view of the bearing apparatus for wheels. It is sectional drawing of the wheel bearing apparatus concerning 2nd Embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning 3rd Embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning 4th Embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning 5th Embodiment of this invention. It is sectional drawing of the wheel bearing apparatus concerning 6th Embodiment of this invention. (A) shows the principal part expanded sectional view of a prior art example, (B) shows explanatory drawing of the improved structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 2 ... Inner member 3 ... Ball | bowl 4, 5 ... Track surface 4a, 5a ... Edge 4aa of a track surface, 5aa ... Auxiliary track surface 4ab, 5ab ... Chamfer 1a, 2a ... Wheel mounting flange 1b ... Car body mounting flange 2B ... Hub wheels 2C, 2D ... Inner ring components a, b ... Curve θ ... Contact angle

Claims (6)

An outer member having a double-row cross-section arc-shaped raceway surface on the inner periphery, an inner member having a cross-section arc-shaped raceway surface facing each of the raceway surfaces, and a multi-row interposed between the double-row raceway surfaces. and a ball of string, a bearing portion of each column Te wheel bearing apparatus odor having a contact angle,
Per the outer member, the upper Symbol least one radial position of the higher shoulder in the cross section of the raceway surface of the column, extending to substantially the center position of the ball, the raceway surface formed with the higher shoulder side of the edges providing the auxiliary raceway surface, the auxiliary raceway surface smoothly came continued from the arcuate curve constituting the cross section of the raceway surface, while the cross-sectional shape composed of small curve or straight curvature than the curve A wheel bearing device, characterized in that a grinding wheel having a cross-sectional shape of a raceway surface is cut into a substantially radial direction of the outer member to obtain a ground surface . The vehicle bearing device according to claim 1, wherein a cross-sectional shape of the auxiliary raceway surface is a straight line that is a tangent to an arc-shaped curve that forms a cross-section of the raceway surface .   3. The vehicle bearing device according to claim 1, wherein a wheel mounting flange is provided on one of the outer member and the inner member.   The wheel bearing device according to any one of claims 1 to 3, wherein a flange for mounting on a vehicle body is provided on one of the outer member and the inner member.   3. The inner member according to claim 1 or 2, wherein the inner member comprises a hub ring of an integral member having a wheel mounting flange and a separate inner ring constituent member fitted to the outer diameter of the end of the hub ring. A bearing device for a wheel having a raceway surface in each row on the hub ring and the inner ring constituting member.   3. The inner ring according to claim 1, wherein the inner member is formed by integrally forming a hub ring of an integral member having a wheel mounting flange and an outer ring of a constant velocity joint, and a part of the inner ring is fitted to an inner diameter of the hub ring. A wheel bearing device comprising: a component member, wherein the hub wheel and the inner ring component member each have a raceway surface in each row.

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