JP2019095005A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel in which an indentation is not formed on a raceway surface. As a result, it is an object of the present invention to provide a bearing device for wheels that does not generate abnormal noise due to indentation or shorten the bearing life. SOLUTION: An outer member 2 having a double-row outer raceway surface 2c / 2d formed on an inner circumference, an inner member 3 having a double-row inner raceway surface 3c / 3d formed on an outer circumference, and the outer side thereof. In the wheel bearing device 1 provided with the member 2 and a plurality of rolling elements 41 interposed between the raceway surfaces 2c, 2d, 3c, and 3d of the inner member 3, the outer member 2 is outside the outer member 2. The annular member 21 is internally fitted, and the auxiliary raceway surface 21c formed on the outer annular member 21 continuously holds the rolling element 41 on the outer raceway surface 2c. [Selection diagram] FIG. 5

Description

  The present invention relates to a bearing device for a wheel.

  Background Art Conventionally, a wheel bearing device that rotatably supports a wheel is known (see Patent Document 1). In the wheel bearing device, the outward member is fixed to the vehicle body. Further, the inner member is disposed inside the outer member, and a plurality of rolling elements are interposed between the raceway surfaces of the outer member and the inner member. Thus, the wheel bearing device constitutes a rolling bearing structure, and the wheel attached to the inward member is rotatable.

  By the way, in such a wheel bearing device, when a large and impulsive external force is applied, an indentation may be formed on the raceway surface of the rolling element. That is, when a large and impulsive external force is applied as the wheel rides on a curb or the like, the rolling element may rise on the raceway surface, so-called edge loading may occur and an indentation may be formed on the raceway surface. Therefore, there has been proposed a wheel bearing device in which the ratio of the depth of the raceway surface to the diameter of the rolling element is a predetermined value or more (see FIG. 12). However, even in such a bearing device for a wheel, there is a problem that an indentation is formed on the raceway surface when an impact external force larger than assumed is applied. As a result, there has been a problem that abnormal noise is generated due to the indentation and the bearing life is reduced.

JP, 2015-224655, A

  An object of the present invention is to provide a bearing device for a wheel which does not have an indentation on a raceway surface. Accordingly, it is an object of the present invention to provide a bearing device for a wheel that does not generate abnormal noise due to indentations or reduce the bearing life.

The first invention is
An outer member having a plurality of rows of outer raceways formed on the inner periphery,
An inner member having a plurality of rows of inner raceways formed on the outer periphery,
A wheel bearing device comprising: a plurality of rolling elements interposed between the outer member and each of the raceways of the inner member;
An outer annular member is internally fitted to the outer member,
The auxiliary raceway surface formed in the outer annular member holds the rolling element continuously to the outer raceway surface.

A second invention relates to the wheel bearing apparatus according to the first invention,
The auxiliary raceway surface holds the rolling element continuously to an outer side end portion of the outer raceway surface formed on the inner side of the outer member.

A third aspect of the invention relates to the wheel bearing apparatus according to the first aspect of the invention.
The auxiliary raceway surface holds the rolling element continuously to the inner side end portion of the outer raceway surface formed on the outer side of the outer member.

A fourth aspect of the invention relates to a wheel bearing apparatus according to any one of the first to third inventions,
An axial cross section of a boundary portion between the outer raceway surface and the auxiliary raceway surface is recessed in an arc shape.

The fifth invention is
An outer member having a plurality of rows of outer raceways formed on the inner periphery,
An inner member having a plurality of rows of inner raceways formed on the outer periphery,
A wheel bearing device comprising: a plurality of rolling elements interposed between the outer member and each of the raceways of the inner member;
An inner annular member is externally fitted to the inner member,
The auxiliary raceway surface formed in the inner annular member holds the rolling element continuously to the inner raceway surface.

A sixth aspect of the invention relates to the wheel bearing apparatus of the fifth aspect,
The auxiliary raceway surface holds the rolling element continuously with the inner side end portion of the inner raceway surface formed on the inner side of the inward member.

A seventh aspect of the invention relates to the wheel bearing apparatus of the fifth aspect,
The auxiliary raceway surface holds the rolling element continuously to an outer side end portion of the inner raceway surface formed on the outer side of the inward member.

An eighth aspect of the invention is the wheel bearing apparatus according to any of the fifth to seventh aspects of the invention,
An axial cross section of a boundary portion between the inner raceway surface and the auxiliary raceway surface is recessed in an arc shape.

  The effects of the present invention are as follows.

  In the wheel bearing device according to the first aspect of the present invention, the outer annular member is internally fitted to the outer member. The auxiliary raceway surface formed on the outer annular member holds the rolling elements continuously to the outer raceway surface. According to such a bearing device for a wheel, even when the rolling element ascends on the outer raceway surface, the occurrence of so-called edge loading can be prevented. Therefore, even when a large and impulsive external force is applied as the wheel rides on a curb or the like, it is possible to prevent the impression of the rolling elements on the outer raceway surface. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life.

  In the wheel bearing device according to the second aspect of the present invention, the auxiliary raceway surface holds the rolling element continuously to the outer side end portion of the outer raceway surface formed on the inner side of the outer member. According to such a bearing device for a wheel, since the outer annular member receives the load even if the rolling element ascends on the outer raceway surface, the impression of the rolling element on the outer raceway surface can be prevented.

  The wheel bearing device pertaining to the third aspect of the invention holds the rolling elements continuously to the inner side end portion of the outer raceway surface in which the auxiliary raceway surface is formed on the outer side of the outer member. According to such a bearing device for a wheel, since the outer annular member receives the load even if the rolling element ascends on the outer raceway surface, the impression of the rolling element on the outer raceway surface can be prevented.

  In the bearing apparatus for a wheel according to the fourth aspect of the present invention, the axial cross section of the boundary portion between the outer raceway surface and the auxiliary raceway surface is recessed in an arc shape. According to such a bearing device for a wheel, it is possible to relieve the stress generated at the boundary between the outer raceway surface and the auxiliary raceway surface.

  In the wheel bearing apparatus according to the fifth aspect of the present invention, the inner annular member is externally fitted to the inner member. The auxiliary raceway surface formed on the inner annular member holds the rolling elements continuously to the inner raceway surface. According to such a bearing device for a wheel, even if the rolling element ascends on the inner raceway surface, it is possible to prevent the occurrence of so-called edge loading. Therefore, even when a large and impulsive external force is applied as the wheel rides on a curb or the like, it is possible to prevent the impression of the rolling elements on the inner raceway surface. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life.

  The wheel bearing device pertaining to the sixth aspect of the invention holds the rolling elements continuously at the inner side end portion of the inner raceway surface where the auxiliary raceway surface is formed on the inner side of the inner member. According to such a bearing device for a wheel, since the inner annular member receives a load even if the rolling element rises on the inner raceway surface, it is possible to prevent the impression of the rolling element from being formed on the inner raceway surface.

  The wheel bearing device pertaining to the seventh invention holds the rolling element continuously to the outer side end portion of the inner raceway surface in which the auxiliary raceway surface is formed on the outer side of the inward member. According to such a bearing device for a wheel, since the inner annular member receives a load even if the rolling element rises on the inner raceway surface, it is possible to prevent the impression of the rolling element from being formed on the inner raceway surface.

  In the wheel bearing device according to the eighth invention, the axial cross section of the boundary portion between the inner raceway surface and the auxiliary raceway surface is recessed in an arc shape. According to such a bearing device for a wheel, it is possible to relieve the stress generated at the boundary between the inner raceway surface and the auxiliary raceway surface.

The figure which shows the bearing apparatus for wheels. The figure which shows the structure of the bearing apparatus for wheels. The figure which shows the partial structure of the bearing apparatus for wheels. The figure which shows the partial structure of the bearing apparatus for wheels. The figure which shows the principal part structure of the bearing apparatus for wheels which concerns on 1st embodiment. The figure which shows the principal part structure of the bearing apparatus for wheels which concerns on 2nd embodiment. The figure which shows the grinding process of the outer side track surface formed in the outward member. The figure which shows the principal part structure of the bearing apparatus for wheels which concerns on 3rd embodiment. The figure which shows the principal part structure of the bearing apparatus for wheels which concerns on 4th embodiment. The figure which shows the grinding process of the inner side track surface formed in the inward member. The figure which shows the principal part structure of the bearing apparatus for wheels which concerns on 5th embodiment. The figure which shows the principal part structure of the bearing apparatus for wheels which is a conventional product.

  First, the wheel bearing device 1 according to the present invention will be described. FIG. 1 is a view showing a wheel bearing device 1. FIG. 2 is a view showing the structure of the wheel bearing device 1. And FIG. 3 and FIG. 4 is a figure which shows the partial structure of the bearing apparatus 1 for wheels.

  The wheel bearing device 1 rotatably supports a wheel. The wheel bearing device 1 includes an outer member 2, an inner member 3, and a rolling element train 4. In the present specification, the "inner side" refers to the vehicle side of the wheel bearing device 1 when attached to the vehicle body, and the "outer side" refers to the wheel bearing device 1 when attached to the vehicle body. Represents the wheel side. Further, “radially outer side” indicates a direction away from the rotation axis A of the inner member 3, and “radially inner side” indicates a direction approaching the rotation axis A of the inner member 3.

  The outer member 2 constitutes an outer ring portion of a rolling bearing structure. A fitting surface 2 a is formed on the inner periphery of the inner side end of the outer member 2. A fitting surface 2 b is formed on the inner periphery of the outer side end of the outer member 2. Further, on the inner periphery adjacent to the fitting surface 2a and the fitting surface 2b, two outer raceway surfaces 2c and 2d are formed. The outer raceway surface 2c faces an inner raceway surface 3c described later. The outer raceway surface 2d faces an inner raceway surface 3d described later. In addition, the outer member 2 is formed with a vehicle mounting flange 2 e that extends radially outward. A plurality of bolt holes 2f are provided in the vehicle body mounting flange 2e. The outer member 2 is attached to a vehicle body (knuckle N described later) by inserting a fastening member (knuckle bolt 34 described later) into each bolt hole 2 f.

  The inward member 3 constitutes an inner ring portion of the rolling bearing structure. The inward member 3 is composed of a hub wheel 31 and an inner ring 32.

  The hub wheel 31 is inserted into the outer member 2. A small diameter step 3a is formed on the outer periphery of the inner end portion of the hub wheel 31 up to the axial center. The small diameter step portion 3a indicates a portion where the outer diameter of the hub wheel 31 is reduced, and the outer peripheral surface thereof has a cylindrical shape with the rotation axis A as a center. Further, the hub wheel 31 is formed with a spline hole 3b penetrating from the inner end to the outer end. Furthermore, an inner raceway surface 3d is formed on the outer periphery of the hub wheel 31 in the axial direction central portion. The inner raceway surface 3 d faces the above-mentioned outer raceway surface 2 d in a state where the hub wheel 31 is inserted into the outer member 2. In addition, the hub wheel 31 is formed with a wheel mounting flange 3 e that extends radially outward. The wheel mounting flange 3e is provided with a plurality of bolt holes 3f around the rotation axis A, and a hub bolt 33 is press-fit into each of the bolt holes 3f.

  The inner ring 32 is externally fitted to the small diameter step 3 a of the hub wheel 31. A fitting surface 3g is formed on the outer periphery of the inner end of the inner ring 32. Further, an inner raceway surface 3c is formed on the outer periphery adjacent to the outer side of the fitting surface 3g. The inner ring 32 forms an inner raceway surface 3 c on the outer periphery of the hub wheel 31 by being externally fitted to the small diameter step portion 3 a of the hub wheel 31. The inner raceway surface 3 c faces the outer raceway surface 2 c described above in a state where the inner ring 32 integrated with the hub wheel 31 is inserted into the inside of the outer member 2. The inner ring 32 is fixed by a crimped portion 3h formed by pushing the tip of the small diameter step portion 3a outward in the radial direction in a state of being externally fitted to the small diameter step portion 3a.

  The rolling element row 4 constitutes a rolling portion of a rolling bearing structure. The inner side rolling element train 4 is configured of a plurality of rolling elements 41 and one cage 42. Similarly, the rolling element row 4 on the outer side is also configured by a plurality of rolling elements 41 and one cage 42.

  The rolling elements 41 are each arranged in a circle at equal intervals by a holder 42. The rolling elements 41 are balls (steel balls). The rolling elements 41 constituting the rolling element row 4 on the inner side are rotatably interposed between the outer raceway surface 2c of the outer member 2 and the inner raceway surface 3c of the inner member 3 (inner ring 32). It is disguised. The rolling elements 41 constituting the rolling element row 4 on the outer side can roll freely between the outer raceway surface 2d of the outer member 2 and the inner raceway surface 3d of the inner member 3 (hub wheel 31). It is interspersed.

  The cage 42 is an annular body in which pockets for containing the rolling elements 41 are formed at equal intervals. The retainer 42 has a spherical wall extending between the rolling elements 41 and the rolling elements 41 adjacent to each other, and holds one rolling element 41 by two spherical walls. For this reason, the cage 42 limits the circumferential displacement (displacement) of the rolling elements 41. Therefore, it can prevent that the adjacent rolling element 41 and the rolling element 41 collide, or that each rolling element 41 rattles.

  By the way, in the present wheel bearing device 1, the inner seal member 5 and the outer seal member are used to seal the annular space S formed between the outer member 2 and the inner member 3 (the hub wheel 31 and the inner ring 32). It has six. In addition, various specifications exist for these seal members 5 and 6, and they are not limited to the specifications disclosed in the present specification.

  The inner side seal member 5 is configured of a slinger 51 and a seal ring 52. The slinger 51 has a substantially L-shaped cross section in the axial direction, and includes a cylindrical fitting portion 51 a and a disk-shaped side plate portion 51 b extending outward in the radial direction. Then, the fitting portion 51a is externally fitted to the fitting surface 3g of the inner member 3 (inner ring 32). On the other hand, the seal ring 52 is obtained by bonding the elastic member 54 to the core metal 53. The metal core 53 has a substantially L-shaped cross section in the axial direction, and has a cylindrical fitting portion 53a and a disk-shaped side plate portion 53b extending inward in the radial direction. Then, the fitting portion 53 a is fitted on the fitting surface 2 a of the outer member 2. In addition, two side lips 54a and 54b are formed in the elastic member 54, and the tip end edges thereof are in contact with the side plate portion 51b of the slinger 51 opposed to each other. Furthermore, one grease lip 54 c is formed on the elastic member 54, and the tip end edge thereof is in contact with or in proximity to the fitting portion 51 a of the opposing slinger 51.

  The outer side sealing member 6 is obtained by bonding an elastic member 62 to a core metal 61. The metal core 61 has a substantially L-shaped cross section in the axial direction, and includes a cylindrical fitting portion 61 a and a disk-shaped side plate portion 61 b extending inward in the radial direction. Then, the fitting portion 61 a is fitted on the fitting surface 2 b of the outer member 2. A side lip 62a and an intermediate lip 62b are formed in the elastic member 62, and the tip end of each side contacts the arc surface 3i connected to the hub flange 3e. Furthermore, one grease lip 62c is formed on the elastic member 62, and the tip end edge thereof is in contact with or close to the axial circumferential surface 3j connected to the arc surface 3i.

  Next, the wheel bearing device 1 according to the first embodiment will be described in detail. FIG. 5 is a view showing a main part structure of the wheel bearing device 1 according to the first embodiment. In addition, (A) in FIG. 5 is the figure which expanded partial area | region R of the bearing apparatus 1 for wheels. Further, (B) in FIG. 5 is an enlarged view of a boundary portion B of the outer raceway surface 2c and the auxiliary raceway surface 21c.

  The wheel bearing device 1 includes an outer annular member 21 fitted in the outer member 2. If it demonstrates concretely, the outer side annular member 21 is fitted by the shoulder part 2m of the outer side track surface 2c formed in the outward member 2. As shown in FIG. The shoulder portion 2m is formed by recessing the inner end portion of the inner peripheral surface adjacent to the outer side of the outer raceway surface 2c radially outward. The outer annular member 21 has a curved surface in which the inner end surface 21c is continuous with the outer raceway surface 2c without any step. In other words, the inner side end face 21c is a curved surface that is smoothly continuous with the outer raceway surface 2c. In the present specification, the inner side end face 21c is defined as "the auxiliary track surface 21c". The auxiliary raceway surface 21c extends to the vicinity of the pitch circle of the rolling elements 41 or to the inner side in the radial direction beyond the pitch circle, and substantially extends the outer raceway surface 2c. And, in any case, the auxiliary raceway surface 21 c has a shape in which the axial cross section thereof is curved along the rolling element 41.

  In the wheel bearing device 1, the outer annular member 21 is made of high carbon chromium bearing steel (SUJ2) which is a high hardness and high rigidity material, but it is made of machine tool steel (SK), ceramics (CE) or the like. It may be configured. Moreover, in this bearing apparatus 1 for wheels, although it has a structure where the outer side annular member 21 is pressingly injected in the shoulder part 2m of the outer side track surface 2c, you may be a structure fixed using an adhesive agent. In this way, since the buffer layer is formed between the outer member 2 and the outer annular member 21, impact can be mitigated. Moreover, the thermal expansion difference of the outward member 2 and the outer side annular member 21 can also be absorbed.

  Thus, in the wheel bearing device 1 according to the first embodiment, the outer annular member 21 is internally fitted to the outer member 2. And the auxiliary raceway surface 21c formed in the outer side annular member 21 continues the outer raceway surface 2c, and holds the rolling element 41. According to the bearing device 1 for a wheel, even when the rolling element 41 lifts the outer raceway surface 2c due to the application of an excessive load or an impact load, so-called generation of edge load can be prevented. Therefore, even when a large and impulsive external force is applied as the wheel rides on a curb or the like, it is possible to prevent the impression of the rolling element 41 on the outer raceway surface 2c. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life.

  In particular, in recent years, due to the increase in output or increase in size of the vehicle, the load above the assumption tends to act on the wheel bearing device 1. In addition, when a low profile tire is adopted for the vehicle, not only the load at the time of cornering, the load on the curb or the like may be exerted during normal running, not only at the time of riding on a curb or the like. As described above, the wheel bearing device 1 according to the present embodiment is useful under the condition that the load more than assumed tends to act, and the load easily generates an indentation on the outer raceway surface 2c.

  Further, in the structure in which the outer raceway surface 2c is extended by shoulder-raising the outer member 2, when the rolling element 41 is raised and an indentation is generated, peeling easily occurs in the outer raceway surface 2c starting from the indentation. . However, in the structure in which the outer ring member 21 of a separate body is fitted to the outer member 2, even if an indentation occurs, it is the auxiliary orbit surface 21c that is separate from the outer raceway surface 2c, even if the indentation occurs. , Hard to affect bearing life. Further, the processability is improved (for example, the processing time is shortened) as compared with the structure in which the outer member 2 is shouldered to extend the outer raceway surface 2c.

  Here, in the present wheel bearing device 1, the contact point between the rolling element 41 and the outer raceway surface 2c is X, the contact point between the rolling element 41 and the inner raceway surface 3c is Y, and an imaginary line connecting the contact point X and the contact point Y is Z In this case, an angular ball bearing is configured such that the imaginary line Z inclines to the outer side as it goes radially outward. Therefore, a load is applied to the outer raceway surface 2c in parallel to the imaginary line Z (see arrow F). However, when the rolling element 41 raises the outer raceway surface 2c, the virtual line Z falls, so that the load is applied to the outer side end portion of the outer raceway surface 2c in a shifted manner. In this case, the outer annular member 21 is a high hardness and high rigidity material, and the auxiliary raceway surface 21c formed on the outer annular member 21 extends radially inward continuously with the outer side end portion of the outer raceway surface 2c. So it can receive such load.

  As described above, in the wheel bearing device 1 according to the first embodiment, the rolling element 41 is continuously connected to the outer side end portion of the outer raceway surface 2c in which the auxiliary raceway surface 21c is formed on the inner side of the outer member 2. keeping. According to the bearing device 1 for a wheel, the outer annular member 21 receives the load even when the rolling element 41 rises up the outer raceway surface 2c, so that the impression of the rolling element 41 on the outer raceway surface 2c is prevented Can.

  In addition, in the wheel bearing device 1, it is preferable that an axial cross section of the boundary portion B between the outer raceway surface 2 c and the auxiliary raceway surface 21 c be recessed in a substantially arc shape (see (B) in FIG. 5). The reason for this is to reduce the load applied to the boundary portion B and to minimize the stress generated at each corner as much as possible.

  As described above, in the wheel bearing device 1 according to the first embodiment, the axial cross section in the boundary portion B between the outer raceway surface 2c and the auxiliary raceway surface 21c may be recessed in an arc shape. According to the wheel bearing device 1, the stress generated at the boundary portion B between the outer raceway surface 2 c and the auxiliary raceway surface 21 c can be relieved.

  Next, the wheel bearing device 1 according to the second embodiment will be described in detail. FIG. 6 is a view showing the main part structure of the wheel bearing device 1 according to the second embodiment. FIG. 6A is an enlarged view of a partial region R of the wheel bearing device 1. Further, (B) in FIG. 6 is an enlarged view of a boundary portion B of the outer raceway surface 2d and the auxiliary raceway surface 22d.

  The wheel bearing device 1 includes an outer annular member 22 fitted in the outer member 2. Specifically, the outer annular member 22 is fitted in the shoulder 2 n of the outer raceway surface 2 d formed on the outer member 2. The shoulder portion 2 n is formed by recessing the outer side end portion of the inner peripheral surface adjacent to the inner side of the outer raceway surface 2 d radially outward. The outer annular member 22 has a curved surface in which the inner end surface 22d is continuous with the outer raceway surface 2d without any step. In other words, the inner side end face 22d is a curved surface that is smoothly continuous with the outer raceway surface 2d. In the present specification, the inner side end face 22d is defined as "auxiliary track face 22d". The auxiliary raceway surface 22d extends to the vicinity of the pitch circle of the rolling element 41 or to the inner side in the radial direction beyond the pitch circle, and substantially extends the outer raceway surface 2d. And, in any case, the auxiliary raceway surface 22 d has a shape in which the axial cross section thereof is curved along the rolling element 41.

  In the wheel bearing device 1, the outer annular member 22 is made of high carbon chromium bearing steel (SUJ2) which is a high hardness and high rigidity material, but it is made of machine tool steel (SK), ceramics (CE), etc. It may be configured. Moreover, in this bearing apparatus 1 for wheels, although it has a structure where the outer side annular member 22 is pressingly injected in the shoulder part 2n of 2 d of outer side track surfaces, it may be a structure fixed using an adhesive agent. In this way, since the buffer layer is formed between the outer member 2 and the outer annular member 22, shock can be mitigated. Moreover, the thermal expansion difference of the outward member 2 and the outer side annular member 22 can also be absorbed.

  As described above, in the wheel bearing device 1 according to the second embodiment, the outer annular member 22 is fitted in the outer member 2. The auxiliary raceway surface 22d formed on the outer annular member 22 is continuous with the outer raceway surface 2d to hold the rolling elements 41. According to the bearing device 1 for a wheel, even if the rolling element 41 lifts the outer raceway surface 2d due to the application of an excessive load or an impact load, so-called edge loading can be prevented. Therefore, even when a large and impulsive external force is applied as the wheel rides on a curb or the like, it is possible to prevent the impression of the rolling element 41 on the outer raceway surface 2d. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life.

  In particular, in recent years, due to the increase in output or increase in size of the vehicle, the load above the assumption tends to act on the wheel bearing device 1. In addition, when a low profile tire is adopted for the vehicle, not only the load at the time of cornering, the load on the curb or the like may be exerted during normal running, not only at the time of riding on a curb or the like. As described above, the wheel bearing device 1 according to the present embodiment is useful under the condition that the load more than assumed easily acts, and the load easily generates an indentation on the outer raceway surface 2d.

  Further, in the structure in which the outer raceway surface 2d is extended by shoulder-raising the outer member 2, when the rolling element 41 is raised and an indentation is generated, peeling easily occurs in the outer raceway surface 2d starting from the indentation. . However, in the structure in which the outer ring member 22 of another body is fitted to the outer member 2, even if an indentation is generated, the indentation is generated in the auxiliary raceway surface 22d separately from the outer raceway surface 2d. , Hard to affect bearing life. Further, the processability is improved (for example, the processing time is shortened) as compared with the structure in which the outer member 2 is shouldered to extend the outer raceway surface 2d.

  Here, in the present wheel bearing device 1, the contact point between the rolling element 41 and the outer raceway surface 2d is X, the contact point between the rolling element 41 and the inner raceway surface 3d is Y, and an imaginary line connecting the contact point X and the contact point Y is Z In this case, an angular ball bearing is configured such that the imaginary line Z inclines to the inner side as it goes radially outward. Therefore, a load is applied to the outer raceway surface 2d in parallel to the imaginary line Z (see arrow F). However, when the rolling element 41 raises the outer raceway surface 2d, the virtual line Z falls, so the load is applied to the inner side end portion of the outer raceway surface 2d in a shifted manner. In this case, the outer annular member 22 is a high hardness and high rigidity material, and the auxiliary raceway surface 22d formed on the outer annular member 22 extends radially inward continuously with the inner side end portion of the outer raceway surface 2d. So it can receive such load.

  As described above, in the wheel bearing device 1 according to the second embodiment, the rolling element 41 is continuously connected to the inner side end portion of the outer raceway surface 2d in which the auxiliary raceway surface 22d is formed on the outer side of the outer member 2. keeping. According to the wheel bearing device 1, the outer annular member 22 receives the load even when the rolling element 41 lifts the outer raceway surface 2 d, so that the impression of the rolling element 41 on the outer raceway surface 2 d is prevented Can.

  In addition, in the wheel bearing device 1, it is preferable that an axial cross section at a boundary portion B between the outer raceway surface 2d and the auxiliary raceway surface 22d is recessed in a substantially arc shape (see (B) in FIG. 6). The reason for this is to reduce the load applied to the boundary portion B and to minimize the stress generated at each corner as much as possible.

  Thus, in the wheel bearing device 1 according to the second embodiment, the axial cross section at the boundary B between the outer raceway surface 2d and the auxiliary raceway surface 22d may be recessed in an arc shape. According to the wheel bearing device 1, the stress generated at the boundary portion B between the outer raceway surface 2 d and the auxiliary raceway surface 22 d can be relaxed.

  By the way, the outer member 2 is completed through various processes. Here, it demonstrates paying attention to the grinding process of outer side track surface 2c * 2d formed in the outward member 2. As shown in FIG. FIG. 7 is a view showing a grinding process of the outer raceway surfaces 2c and 2d formed on the outer member 2. As shown in FIG.

  The grinding process is a process of reducing the surface roughness of the outer raceway surfaces 2c and 2d formed on the outer member 2. The outer raceway surfaces 2c and 2d are already formed on the outer member 2 before the grinding process, but their surface roughness is large. Therefore, in the grinding process, the outer raceway surface 2c is polished with the polishing tool (whole grinding wheel) T applied to the outer raceway surface 2c to finish the outer raceway surface 2c precisely. Similarly, the polishing tool T is applied to the outer raceway surface 2d for polishing to finish the outer raceway surface 2d precisely. The auxiliary raceway surface 21c of the outer annular member 21 may be finished together when finishing the outer raceway surface 2c. The auxiliary raceway surface 22d of the outer annular member 22 may also be finished together when finishing the outer raceway surface 2d. The auxiliary raceways 21c and 22d are effective when an impact external force larger than expected is applied, and the rolling elements 41 are not always in contact. Therefore, it is not necessary to make the surface roughness of the auxiliary raceway surfaces 21c and 22d equal to the outer raceway surfaces 2c and 2d. Even if the auxiliary raceway surfaces 21c and 22d are damaged, there is almost no influence on the outer raceway surfaces 2c and 2d.

  Next, the wheel bearing device 1 according to the third embodiment will be described in detail. FIG. 8 is a view showing a main part structure of the wheel bearing device 1 according to the third embodiment. In addition, (A) in FIG. 8 is the figure which expanded partial area | region R of the bearing apparatus 1 for wheels. Further, (B) in FIG. 8 is an enlarged view of a boundary portion B of the inner raceway surface 3c and the auxiliary raceway surface 33c.

  The wheel bearing device 1 includes an inner annular member 33 fitted on the inner member 3. If it demonstrates concretely, the inner side annular member 33 is externally fitted by the shoulder part 3m of the inner side track surface 3c formed in the inward member 3 (inner ring 32). The shoulder portion 3m is formed by recessing the outer end portion of the outer peripheral surface adjacent to the inner side of the outer raceway surface 3c radially inward. The inner annular member 33 has a curved surface in which the outer end surface 33c is continuous with the inner raceway surface 3c without any step. In other words, the outer side end surface 33c is a curved surface that is smoothly continuous with the inner raceway surface 3c. In the present specification, the outer side end surface 33c is defined as "the auxiliary track surface 33c". The auxiliary raceway surface 33c extends to the vicinity of the pitch circle of the rolling element 41 or to the outside in the radial direction beyond the pitch circle, and substantially extends the inner raceway surface 3c. In any case, the auxiliary raceway surface 33 c has a shape in which the axial cross section thereof is curved along the rolling elements 41.

  In the wheel bearing device 1, the inner annular member 33 is made of high carbon chromium bearing steel (SUJ2) which is a high hardness and high rigidity material, but it is made of machine tool steel (SK), ceramics (CE), etc. It may be configured. Moreover, in this bearing apparatus 1 for wheels, although it has a structure where the inner side annular member 33 is press-fit in the shoulder part 3m of the inner side track surface 3c, you may be a structure fixed using an adhesive agent. In this way, since the buffer layer is formed between the inner member 3 and the inner annular member 33, shock can be mitigated. Moreover, the thermal expansion difference of the inward member 3 and the inner annular member 33 can also be absorbed.

  As described above, in the wheel bearing device 1 according to the third embodiment, the inner annular member 33 is externally fitted to the inner member 3. And the auxiliary raceway surface 33c formed in the inner side annular member 33 continues the inner raceway surface 3c, and holds the rolling element 41. According to the bearing device 1 for a wheel, even if the rolling element 41 lifts up the inner raceway surface 3c due to the application of an excessive load or an impact load, so-called edge loading can be prevented. Therefore, even if a large and impulsive external force is applied as the wheel rides on a curb or the like, it is possible to prevent the impression of the rolling element 41 on the inner raceway surface 3c. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life.

  In addition, the structure in which the separate inner annular member 33 is fitted to the inner ring 32 can easily secure a space in which the inner seal member 5 is accommodated as compared with the structure in which the inner ring 32 is shouldered to extend the inner raceway surface 3c. Therefore, the sealing performance of the annular space S can be enhanced by adopting the inner side seal member 5 having a large cross-sectional area.

  Further, in the structure in which the inner race 32 is shouldered to extend the inner raceway surface 3c, if the rolling element 41 is raised and an indentation is generated, peeling easily occurs on the inner raceway surface 3c starting from the indentation. However, in the structure in which the separate inner annular member 33 is fitted to the inner ring 32, even if an indentation occurs, it is the auxiliary raceway surface 33c that is separate from the inner raceway surface 3c even if the indentation occurs. It is hard to affect the life. Further, the processability is improved (for example, the processing time is shortened) as compared with the structure in which the inner race 32 is shouldered to extend the inner raceway surface 3c.

  Here, in the present wheel bearing device 1, the contact point between the rolling element 41 and the outer raceway surface 2c is X, the contact point between the rolling element 41 and the inner raceway surface 3c is Y, and an imaginary line connecting the contact point X and the contact point Y is Z In this case, an angular ball bearing is configured such that the imaginary line Z inclines to the outer side as it goes radially outward. Therefore, a load is applied to the inner raceway surface 3c in parallel to the imaginary line Z (see arrow F). However, when the rolling element 41 lifts up the inner raceway surface 3c, the virtual line Z falls, so that the load is applied to the inner side end portion of the inner raceway surface 3c in a shifted manner. In this case, the inner annular member 33 is a high hardness and high rigidity material, and the auxiliary raceway surface 33c formed on the inner annular member 33 extends radially outward continuously to the inner side end portion of the inner raceway surface 3c. So it can receive such load.

  As described above, in the wheel bearing device 1 according to the third embodiment, the rolling elements 41 are continuously connected to the inner side end portion of the inner raceway surface 3c in which the auxiliary raceway surface 33c is formed on the inner side of the inward member 3. keeping. According to the wheel bearing device 1, the inner annular member 33 receives the load even when the rolling elements 41 move up on the inner raceway surface 3 c, so that the impression of the rolling elements 41 on the inner raceway surface 3 c is prevented Can.

  In addition, in the wheel bearing device 1, it is preferable that an axial cross section at a boundary portion B between the inner raceway surface 3c and the auxiliary raceway surface 33c is recessed in a substantially arc shape (see (B) in FIG. 8). The reason for this is to reduce the load applied to the boundary portion B and to minimize the stress generated at each corner as much as possible.

  As described above, in the wheel bearing device 1 according to the third embodiment, the axial cross section at the boundary portion B between the inner raceway surface 3c and the auxiliary raceway surface 33c may be recessed in an arc shape. According to the wheel bearing device 1, it is possible to relieve the stress generated at the boundary portion B between the inner raceway surface 3 c and the auxiliary raceway surface 33 c.

  Next, the wheel support bearing assembly 1 according to the fourth embodiment will be described in detail. FIG. 9 is a view showing a main part structure of the wheel bearing device 1 according to the fourth embodiment. (A) in FIG. 9 is an enlarged view of a partial region R of the wheel bearing device 1. Further, (B) in FIG. 9 is an enlarged view of a boundary portion B of the inner raceway surface 3d and the auxiliary raceway surface 34d.

  The wheel bearing device 1 includes an inner annular member 34 fitted on the inner member 3. Specifically, the inner annular member 34 is externally fitted to the shoulder 3n of the inner race 3d formed on the inner member 3 (the hub wheel 31). The shoulder portion 3 n is formed by recessing the inner end portion of the outer peripheral surface adjacent to the outer side of the outer raceway surface 3 d radially inward. The inner annular end surface 34d of the inner annular member 34 is a curved surface which continues without any step relative to the inner raceway surface 3d. In other words, the inner side end surface 34d is a curved surface that is smoothly continuous with the inner raceway surface 3d. In the present specification, the outer side end surface 34d is defined as "the auxiliary track surface 34d". The auxiliary raceway surface 34d extends to the vicinity of the pitch circle of the rolling elements 41 or to the outside in the radial direction beyond the pitch circle, and substantially extends the inner raceway surface 3d. And, in any case, the auxiliary raceway surface 34 d has a shape in which the axial cross section thereof is curved along the rolling element 41.

  In the wheel bearing device 1, the inner annular member 34 is made of high carbon chromium bearing steel (SUJ2) which is a high hardness and high rigidity material, but it is made of machine tool steel (SK), ceramics (CE), etc. It may be configured. Moreover, in this bearing apparatus 1 for wheels, although it has a structure where the inner annular member 34 is press-fit in the shoulder part 3n of 3 d of inner side track surfaces, it may be a structure fixed using an adhesive agent. In this way, since the buffer layer is formed between the inner member 3 and the inner annular member 34, shock can be mitigated. Moreover, the thermal expansion difference of the inward member 3 and the inner annular member 34 can also be absorbed.

  As described above, in the wheel bearing device 1 according to the fourth embodiment, the inner annular member 34 is externally fitted to the inner member 3. The auxiliary raceway surface 34d formed on the inner annular member 34 is continuous with the inner raceway surface 3d to hold the rolling elements 41. According to the bearing device 1 for a wheel, even if the rolling element 41 lifts up the inner raceway surface 3d due to the application of an excessive load or an impact load, so-called edge loading can be prevented. Therefore, even when a large and impulsive external force is applied as the wheel rides on a curb or the like, it is possible to prevent the impression of the rolling element 41 on the inner raceway surface 3d. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life.

  In addition, the structure in which the separate inner annular member 34 is fitted to the hub wheel 31 secures a space in which the outer side seal member 6 is accommodated, as compared with the structure in which the hub ring 31 is shouldered to extend the inner raceway surface 3d. Cheap. Therefore, the sealing performance of annular space S can be improved by adopting outer side seal member 6 with a large cross-sectional area.

  Further, in the structure in which the inner raceway surface 3d is extended by shoulder-raising the hub wheel 31, when the rolling element 41 is raised and an indentation is generated, peeling easily occurs in the inner raceway surface 3d starting from the indentation. However, in the structure in which the separate inner annular member 34 is fitted to the hub wheel 31, even if an indentation is generated, the indentation is generated in the auxiliary raceway surface 34d separate from the inner raceway surface 3d, Hard to affect bearing life. Further, the processability is improved (for example, the processing time is shortened) as compared with the structure in which the hub wheel 31 is shouldered to extend the inner raceway surface 3d.

  Here, in the present wheel bearing device 1, the contact point between the rolling element 41 and the outer raceway surface 2d is X, the contact point between the rolling element 41 and the inner raceway surface 3d is Y, and an imaginary line connecting the contact point X and the contact point Y is Z In this case, an angular ball bearing is configured such that the imaginary line Z inclines to the inner side as it goes radially outward. Therefore, a load is applied to the inner raceway surface 3d in parallel to the imaginary line Z (see arrow F). However, when the rolling element 41 lifts up the inner raceway surface 3d, the virtual line Z falls, so the load is applied to the outer side end portion of the inner raceway surface 3d in a shifted manner. In this case, the inner annular member 34 is a high hardness and high rigidity material, and the auxiliary raceway surface 34d formed on the inner annular member 34 extends radially outward continuously with the outer side end portion of the inner raceway surface 3d. So it can receive such load.

  As described above, in the wheel bearing device 1 according to the fourth embodiment, the rolling elements 41 are continuously connected to the outer side end portion of the inner raceway surface 3 d in which the auxiliary raceway surface 34 d is formed on the outer side of the inward member 3. keeping. According to the wheel bearing device 1, the inner annular member 34 receives the load even when the rolling element 41 lifts up the inner raceway surface 3 d, so that the impression of the rolling element 41 on the inner raceway surface 3 d is prevented Can.

  In addition, in the wheel bearing device 1, it is preferable that an axial cross section at a boundary portion B between the inner raceway surface 3d and the auxiliary raceway surface 34d is recessed in a substantially arc shape (see (B) in FIG. 9). The reason for this is to reduce the load applied to the boundary portion B and to minimize the stress generated at each corner as much as possible.

  As described above, in the wheel bearing device 1 according to the fourth embodiment, the axial cross section at the boundary portion B between the inner raceway surface 3d and the auxiliary raceway surface 34d may be recessed in an arc shape. According to the wheel bearing device 1, the stress generated at the boundary portion B between the outer raceway surface 3 d and the auxiliary raceway surface 34 d can be relieved.

  By the way, the inward member 3 is completed through various processes. Here, it demonstrates paying attention to the grinding process of inner side track surface 3c * 3d formed in the inward member 3. FIG. FIG. 10 is a view showing a grinding process of the outer races 3c and 3d formed on the inner member 3. As shown in FIG.

  The grinding process is a process of reducing the surface roughness of the inner raceway surfaces 3c and 3d formed on the hub wheel 31 and the inner ring 32. The inner raceway surface 3d is already formed on the hub wheel 31 before the grinding process, but the surface roughness is large. Moreover, although the inner raceway surface 3c is already formed in the inner ring 32, this surface roughness is also large. Therefore, in the grinding process, the polishing tool T is applied to the inner raceway surface 3d for polishing to finish the inner raceway surface 3d precisely. Similarly, a polishing tool T is applied to the inner raceway surface 3c for polishing to finish the inner raceway surface 3c precisely. The auxiliary raceway surface 34d of the inner annular member 34 may be finished together when finishing the inner raceway surface 3d. The auxiliary raceway surface 33c of the inner annular member 33 may also be finished together when finishing the inner raceway surface 3c. The auxiliary raceways 33c and 34d are effective when an impact external force larger than expected is applied, and the rolling elements 41 are not always in contact with each other. Therefore, it is not necessary to make the surface roughness of the auxiliary raceway surfaces 33c and 34d equal to those of the inner raceway surfaces 3c and 3d. Even if the auxiliary raceways 33c and 34d are damaged, there is almost no influence on the inner raceways 3c and 3d. In addition, externally fitting and caulking the inner ring 32 on the small diameter step portion 3a of the hub wheel 31 is the final step of completing the wheel bearing device 1.

  Next, the wheel bearing device 1 according to the fifth embodiment will be described in detail. FIG. 11 is a view showing the main part structure of the wheel bearing device 1 according to the fifth embodiment. In addition, (A) and (B) in FIG. 11 are the figures which expanded the partial area | region R of the bearing apparatus 1 for wheels.

  The wheel bearing device 1 according to the fifth embodiment is one to which all the feature points of the above-described embodiments are applied. Specifically, the wheel bearing apparatus 1 includes the outer annular members 21 and 22 fitted in the outer member 2 and the inner annular members 33 and 34 fitted in the inner member 3. (Refer to (A) in FIG. 11).

  According to the bearing device 1 for a wheel, even when the rolling element 41 ascends on the outer raceway surfaces 2c and 2d, the occurrence of so-called edge loading can be prevented. In addition, even if the rolling elements 41 raise the inner raceway surfaces 3c and 3d, it is possible to prevent the occurrence of so-called edge loading. Therefore, even if a large and impulsive external force is applied as the wheel rides on a curb or the like, the impression of the rolling elements 41 on the outer raceway surfaces 2c and 2d and the inner raceway surfaces 3c and 3d is prevented. Can. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life. In addition, the other effects are similarly exhibited.

  Furthermore, when the two outer annular members 21 and 22 are provided as in the present wheel bearing device 1, these outer annular members 21 and 22 may be integrated into one outer annular member 23 ( Refer to (B) in FIG.

  In the wheel bearing device 1 as well, it is possible to prevent the impression of the rolling element 41 on the outer raceway surfaces 2c and 2d and the inner raceway surfaces 3c and 3d. As a result, it is possible to suppress the generation of abnormal noise due to the indentation and to prevent the deterioration of the bearing life. In addition, the other effects are similarly exhibited.

  The wheel bearing device 1 in the present application includes a third member including an outer member 2 having a vehicle body mounting flange 2 e and an inner member 3 in which one inner ring 32 is fitted to the hub wheel 31. Although it has a generation structure, it is not limited to this. For example, the second generation structure of the inward member rotation specification configured by the outward member having the vehicle body mounting flange and the inward member consisting of a pair of inner rings, or the outside having the wheel attachment flange It may be a second generation structure of an outward member rotation specification configured by a square member and an inward member composed of a pair of inner rings. In addition, it may be a first generation structure configured by an outer member fitted in a housing or the like and an inner member consisting of a pair of inner rings.

  Finally, the invention in the present application is not limited to the respective embodiments, but is merely an example, and it goes without saying that the invention can be embodied in various forms without departing from the scope of the present invention. The scope of the invention is indicated by the description of the claims, and further includes the equivalent meaning described in the claims, and all the modifications within the scope.

1 Wheel bearing device 2 Outer member 2c Outer raceway surface 2d Outer raceway surface 21 Outer annular member 21c Auxiliary raceway surface 22 Outer annular member 22d Auxiliary raceway surface 3 Inner member 3c Inner raceway surface 3d Inner raceway surface 31 Hub wheel 32 Inner ring 33 inner annular member 33 c auxiliary raceway surface 34 inner annular member 34 d auxiliary raceway surface 4 rolling element train 41 rolling element 42 cage B boundary portion

Claims (8)

An outer member having a plurality of rows of outer raceways formed on the inner periphery,
An inner member having a plurality of rows of inner raceways formed on the outer periphery,
A wheel bearing device comprising: a plurality of rolling elements interposed between the outer member and each of the raceways of the inner member;
An outer annular member is internally fitted to the outer member,
A wheel bearing device characterized in that an auxiliary raceway surface formed in the outer annular member holds the rolling element continuously to the outer raceway surface.   The wheel according to claim 1, wherein the auxiliary raceway surface holds the rolling element continuously to the outer side end of the outer raceway surface formed on the inner side of the outer member. Bearing equipment.   The wheel according to claim 1, wherein the auxiliary raceway surface holds the rolling element continuously to the inner side end portion of the outer raceway surface formed on the outer side of the outer member. Bearing equipment.   The wheel bearing device according to any one of claims 1 to 3, wherein an axial cross section of a boundary portion between the outer raceway surface and the auxiliary raceway surface is recessed in an arc shape. An outer member having a plurality of rows of outer raceways formed on the inner periphery,
An inner member having a plurality of rows of inner raceways formed on the outer periphery,
A wheel bearing device comprising: a plurality of rolling elements interposed between the outer member and each of the raceways of the inner member;
An inner annular member is externally fitted to the inner member,
A wheel bearing device characterized in that an auxiliary raceway surface formed on the inner annular member holds the rolling element continuously to the inner raceway surface.   The wheel according to claim 5, wherein the auxiliary raceway surface holds the rolling element continuously to the inner side end portion of the inner raceway surface formed on the inner side of the inward member. Bearing equipment.   The wheel according to claim 5, wherein the auxiliary raceway surface holds the rolling element continuously to the outer side end of the inner raceway surface formed on the outer side of the inward member. Bearing equipment.   The wheel bearing device according to any one of claims 5 to 7, wherein an axial cross section of the boundary portion between the inner raceway surface and the auxiliary raceway surface is recessed in an arc shape.

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