JP2019123265A - Wheel bearing device and its manufacturing method - Google Patents

Abstract

To hinder rocking of flange and improve sealing performance in a wheel bearing device.SOLUTION: A hub-shaft manufacturing includes: a lathe turning step in which a lathe turning for a flange surface 31 and a lathe turning for an annular surface 19 including part of a seal surface 29 are performed; a first grind step in which the annular surface 19 is ground; a press-in step in which a bolt 28 is pressed into a bolt hole 32; and a second grinding step in which, after the press-in step, the flange surface 31 is ground using the ground annular surface 19 as a reference surface. In the second grinding step, a flange surface 31 is ground while a cylindrical jig is disposed in contact with a second annular area K2, on the radially outside, of an annular surface 32 while a first annular area K1 serving as part of the seal surface 29 is left from the second annular area.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bearing device for a wheel and a method of manufacturing the same.

  In vehicles, such as a motor vehicle, in order to support a wheel, the bearing apparatus for wheels (hub unit) is used. The wheel bearing device includes an outer ring member attached to the vehicle body side, an inner shaft member to which the wheel is attached, and a plurality of rolling elements (balls) disposed between the outer ring member and the inner shaft member. FIG. 8 is a cross-sectional view of a hub shaft of the inner shaft member. The hub axle 90 has a shaft portion 91 and a flange portion 92 provided on one side in the axial direction of the shaft portion 91. Wheels and a brake rotor (not shown) are attached to the flange portion 92. A seal surface 93 is provided between the shaft portion 91 and the flange portion 92. The lip of the seal attached to the outer ring member (not shown) comes in contact with the seal surface 93, and the entry of foreign matter from the outside is prevented. For this purpose, the sealing surface 93 is polished.

  The flange portion 92 has a flange surface 94 on one side in the axial direction and a bolt hole 95. The bolt holes 95 are pressed into bolts 96 for fixing the wheel and the brake rotor (not shown). The flange surface 94 is a surface in contact with the brake rotor. Patent Document 1 discloses a conventional vehicle bearing device.

JP, 2014-156197, A

  As shown in FIG. 8, a bolt 96 is press-fit into the bolt hole 95 of the flange portion 92. For this reason, the flange portion 92 may be distorted, and a shake (also referred to as “flange runout”) occurs on the flange surface 94. The above-mentioned vibration causes the generation of a brake judder noise.

  So, in patent document 1, after press-fitting the volt | bolt 96 in the bolt hole 95, in order to eliminate a flange runout, with respect to the flange surface 94, grinding | polishing process is performed. In this polishing process, the seal surface 93 which has been previously polished is used as a reference. That is, the cylindrical jig 99 is brought into contact with the sealing surface 93.

  As described above, in order to eliminate the flange runout, the jig 99 is brought into contact with the sealing surface 93 to polish the flange surface 94. However, during the processing, slippage occurs between the jig 99 and the seal surface 93. This slippage may cause intermittent rubbing marks on the sealing surface 93, which may affect the sealing performance.

  Therefore, an object of the present invention is to provide a method of manufacturing a bearing device for a wheel capable of suppressing a flange runout and improving sealing performance, and a bearing device for a wheel manufactured by the method.

  The method for manufacturing a bearing device for a wheel according to the present invention includes a cylindrical outer ring member, a shaft portion provided radially inward of the outer ring member, and one axial side of the shaft portion. An inner shaft member having a hub shaft including a flange portion and having a sealing surface provided between the shaft portion and the flange portion, which is disposed between the outer ring member and the inner shaft member A rolling element, and a seal having a lip attached to one axial side of the outer ring member and in contact with the sealing surface; the flange portion has a flange surface on one axial side, and the flange portion in the axial direction A method of manufacturing a bearing device for a wheel having a bolt hole passing through and an annular surface on the other side in the axial direction including a part of the seal surface, the hub shaft manufacturing process and the hub shaft manufacturing process The inner shaft member with the hub shaft An assembling step of combining the outer ring member, the rolling element, and the seal, and the hub shaft manufacturing step includes a turning step of turning the flange surface and a turning step of the annular surface; grinding the annular surface A second polishing step of polishing the flange surface after the press-fitting step, wherein the annular surface that has been polished is used as a reference surface; and In the second polishing step, a first annular region, which is the part of the sealing surface on the radially inward side, of the annular surface is opened, and a cylindrical shape is formed in the second annular region on the radially outer side. The flange surface is polished with the jig applied.

  According to this manufacturing method, since the flange surface is polished after the bolt is pressed into the bolt hole of the flange portion in the hub shaft manufacturing process, it is possible to suppress the flange runout. In the second polishing step, polishing of the flange surface is performed using the annular surface including a part of the seal surface as a reference surface. However, in this case, the cylindrical jig is not in contact with the first annular region that is a part of the radially inward sealing surface, but in a state in which the cylindrical jig is applied to the second annular region radially outward. As a result, no rub mark is left on the sealing surface, and the sealing performance can be improved.

  In addition, the seal surface includes a part of the outer peripheral surface on one side in the axial direction of the shaft portion, and a virtual circle having a diameter equal to or more than a value obtained by adding 10 mm to the outer diameter of a part of the outer peripheral surface. Preferably, the jig is applied to the second annular region as a boundary between the first annular region and the second annular region. According to this method, although rubbing marks may be left in the second annular region, rubbing marks do not occur on the sealing surface.

  The wheel bearing device manufactured by the manufacturing method is provided on one side of the cylindrical outer ring member, a shaft portion provided radially inward of the outer ring member, and the axial portion of the shaft portion. An inner shaft member having a hub shaft including a flange portion provided with a sealing surface between the shaft portion and the flange portion, the inner shaft member being disposed between the outer ring member and the inner shaft member And a seal having a lip attached to one side in the axial direction of the outer ring member and in contact with the seal surface, and the flange portion has a flange surface on one side in the axial direction and the flange portion A bolt which is press-fit into a bolt hole penetrating in a direction, and an annular surface on the other side in the axial direction including a part of the sealing surface, the flange surface is a polishing surface, and of the annular surfaces The radially inner first annular region of the A polished surface which is a part of the surface, the radially outer side of the second annular region of said annular surfaces, said sealing surface and the surface state is different polishing surfaces.

  Further, in the wheel bearing device, a part of the outer peripheral surface on one side in the axial direction of the shaft portion is a polishing surface that is continuous with the part of the sealing surface, and the first annular region and the second annular region The boundary with the annular region is preferably located on an imaginary circle having a diameter equal to or more than a value obtained by adding 10 mm to the outer diameter of a part of the outer peripheral surface.

  According to the present invention, it is possible to suppress the flange runout and to improve the sealing performance.

It is sectional drawing which shows an example of the bearing apparatus for wheels of this invention. It is a flowchart which shows a manufacturing method. It is explanatory drawing of a turning process. It is explanatory drawing of a 1st grinding | polishing process. It is a schematic diagram explaining the shake (distortion) of an annular surface. It is explanatory drawing of a 2nd grinding | polishing process. It is sectional drawing of the XX arrow of a hub axle shown in FIG. It is a sectional view of a hub axis which an inner shaft member has.

[Regarding Configuration of Wheel Bearing Device]
FIG. 1 is a cross-sectional view showing an example of a wheel bearing device of the present invention. The wheel bearing device (hub unit) 10 is attached to a suspension system (knuckle) provided on the vehicle body side of the automobile, and rotatably supports the wheel. The wheel bearing device 10 includes a cylindrical outer ring member 12, an inner shaft member 11, a rolling element 13, a cage 14, a first seal 15 provided on one side in the axial direction, and the other in the axial direction. And a second seal 16 provided on the side. In the wheel bearing device 10, the axial direction is a direction parallel to the central axis C (hereinafter referred to as a bearing central axis C) of the wheel bearing device 10. Moreover, a radial direction is a direction orthogonal to the said axial direction.

  The outer ring member 12 has an outer ring main body portion 21 having a cylindrical shape, and a fixing flange portion 22 extending radially outward from the outer ring main body portion 21. Outer ring raceway surfaces 12 a and 12 b are formed on the inner peripheral side of the outer ring main body 21. The outer ring member 12 is attached to a knuckle (not shown) which is a vehicle body side member by a flange portion 22, whereby the wheel bearing device 10 including the outer ring member 12 is fixed to the vehicle body. In a state where the wheel bearing device 10 is fixed to the vehicle body, the wheel mounting flange portion 27 side of the inner shaft member 11 described later is the outside of the vehicle. That is, one axial direction side in which the flange portion 27 is provided is the vehicle outer side, and the other axial direction side opposite thereto is the vehicle inner side.

  The inner shaft member 11 has a hub shaft (inner shaft) 23 and an inner ring 24 attached to the other side of the hub shaft 23 in the axial direction. The hub axle 23 includes a shaft portion 26 provided radially inward of the outer ring member 12 and a flange portion 27 provided on one axial side of the shaft portion 26. The shaft portion 26 is a long shaft portion in the axial direction. The flange portion 27 is provided so as to extend radially outward from one axial side of the shaft portion 26. A seal surface 29 is provided between the shaft portion 26 and the flange portion 27.

  As shown in the enlarged view of FIG. 1, the sealing surface 29 includes an annular sealing surface 29a, a cylindrical sealing surface 29b, and a rounded surface 29c. The annular sealing surface 29 a is in contact with a lip 30 a which the seal 15 has and extends to the flange 27 side. The cylindrical sealing surface 29 b faces the lip 30 b which the seal 15 has and extends to the shaft 26 side. The annular seal surface 29 a is a surface along a plane orthogonal to the bearing central axis C as a whole. The cylindrical sealing surface 29 b is a part of the outer peripheral surface on one side in the axial direction of the shaft portion 26, and is a surface along a cylindrical surface parallel to the bearing central axis C as a whole. The rounded surface 29c is a surface connecting the annular sealing surface 29a and the annular sealing surface 29a.

  The inner ring 24 is an annular member, and is externally fitted and fixed to the small diameter portion 39 on the other side in the axial direction of the shaft portion 26. An axial raceway surface 11 a is formed on the outer peripheral surface of the shaft portion 26, and an inner raceway surface 11 b is formed on the outer peripheral surface of the inner race 24.

  A plurality of balls, which are rolling elements 13, are disposed between the outer raceway surface 12a and the axial raceway surface 11a on one side in the axial direction. A plurality of balls, which are rolling elements 13, are disposed between the outer ring raceway surface 12b and the inner ring raceway surface 11b on the other side in the axial direction. The rolling elements (balls) 13 are arranged in two rows between the outer ring member 12 and the inner shaft member 11.

  The flange portion 27 has a flange surface 31 on one side in the axial direction, a bolt hole 32 penetrating the flange portion 27 in the axial direction, and an annular surface 19 on the other side in the axial direction. Wheel mounting bolts 28 are press-fitted into the bolt holes 32. The flange surface 31 is an annular surface provided in the radially outer area of the flange portion 27. A brake rotor (not shown) is attached in contact with the flange surface 31. The flange surface 31 is a polished surface.

  In the enlarged view of FIG. 1, the annular surface 19 includes a part of the sealing surface 29 (annular sealing surface 29a). That is, although the annular surface 19 is a single annular surface, it is divided into the radially inner first annular region K1 and the radially outer second annular region K2. FIG. 7 is a cross-sectional view of the hub shaft 23 shown in FIG. 1 as viewed in the direction of arrows XX, and is a view of the annular surface 19 and the periphery thereof from the axial direction. In FIG. 7, the boundary between the first annular region K1 and the second annular region K2 is indicated by a two-dot chain line L. The first annular region K1 is a part of the sealing surface 29 (annular sealing surface 29a) and is a polishing surface. The second annular region K2 is a polishing surface, but the surface state is different from that of the sealing surface 29 (annular sealing surface 29a). The difference in surface state will be specifically described. When compared with the first annular area K1 (the annular seal surface 29a), the gloss is partially different in the second annular area K2. The first annular region K1 (annular seal surface 29a) has uniform gloss along the circumferential direction. On the other hand, in the second annular region K2, the gloss is partially reduced along the circumferential direction. This is because in the second annular region K2, rubbing marks (scratches) caused by contact with a jig 41 (see FIG. 6) described later are present. In the area of the rubbing marks, the surface roughness (average value) is different (higher) from that of the first annular area K1, and the gloss is reduced.

  As shown in the enlarged view of FIG. 1, the cylindrical seal surface 29 b included in the seal surface 29 is a part of the outer peripheral surface on one side in the axial direction of the shaft portion 26. The cylindrical seal surface 29 b is a polished surface that is continuous via the annular seal surface 29 a and the rounded surface 29 c. In FIG. 7, the boundary between the first annular region K1 and the second annular region K2 is a virtual circle having a diameter D2 equal to or more than a value obtained by adding 10 mm to the outer diameter D1 of the cylindrical sealing surface 29b. ) Located above (D2 2 D1 + 10 mm).

  The first seal 15 is attached to one end of the outer ring member 12 in the axial direction. The first seal 15 has a rubber lip 30 a, which contacts the sealing surface 29. The first seal 15 prevents foreign matter such as muddy water from invading the inside of the bearing in which the rolling element 13 is provided from between the outer ring member 12 and the inner shaft member 11 on one side in the axial direction. The second seal 16 prevents foreign matter such as muddy water from intruding into the bearing from between the outer ring member 12 and the inner shaft member 11 on the other side in the axial direction.

[About the manufacturing method]
A method of manufacturing the wheel bearing device 10 having the above configuration will be described. FIG. 2 is a flowchart showing the manufacturing method. This manufacturing method includes a process (manufacturing process) S10 for manufacturing each element constituting the wheel bearing device 10 (see FIG. 1) and an assembling process S20 for assembling each element obtained in the manufacturing process S10. . About the manufacturing method of elements other than hub axis 23, it is the same method as before, and explanation is omitted here. The method of manufacturing the hub axle 23 (hub axle manufacturing process) is as follows. In addition, heat processing, such as hardening treatment, may be included in the manufacturing process of each element.

[About hub axle manufacturing process]
As shown in FIG. 2, in the present embodiment, the turning process S11, the first polishing process S12, the press-in process S13, and the second polishing process S14 are performed in this order, whereby the hub axle 23 is manufactured. There is also a method in which the press-in step 13 is performed before the first polishing step S12.

In the turning process S11, turning of the flange surface 31 and turning of the annular surface 19 are performed.
In the first polishing step S12, the annular surface 19 is polished.
In the press-in step S13, the bolt 28 is press-fitted into the bolt hole 32.
In the second polishing step S14, a portion of the ground annular surface 19 (the second annular region K2, see FIG. 7) serves as a reference surface, and the flange surface 31 is polished.

Hereinafter, each process included in the hub axle manufacturing process will be described.
The turning process S11 is performed as follows. Turning is performed on a predetermined portion (necessary portion) of an intermediate product to be the hub axle 23 manufactured by forging. In FIG. 3, the flange surface 31, the annular surface 19, the rounded surface 29 c and the cylindrical seal surface 29 b included in the seal surface 29, and the outer peripheral surface of the shaft portion 26 of the hub shaft 23. 33 are included. The outer peripheral surface 33 of the shaft portion 26 includes a small diameter outer peripheral surface 34 in which the shaft raceway surface 11 a and the inner ring 24 (see FIG. 1) are fitted. The order in which the turning process is performed on these portions to be turned can be changed. In the present embodiment, after the flange surface 31 is turned, the annular surface 19 and other surfaces are turned. Turning of the sealing surface 29 and other surfaces may be performed on the basis of the turned flange surface 31. As described above, in the turning process S11, the rounded surface 29c and the cylindrical seal surface 29b included in the seal surface 29 are also turned along with the turning process of the flange surface 31 and the annular surface 19. Furthermore, in the present embodiment, the outer peripheral surface 33 of the shaft body portion 26 of the hub axle 23 is turned as a whole.

  In the turning process S11, the turning process may be divided into a plurality of times at each turning target location. For example, the flange surface 31 may be divided into rough processing and semi-finishing processing, and turning may be performed in a plurality of steps. In addition, turning may be performed on the annular surface 19 in a plurality of processes, divided into rough processing and semi-finishing processing.

  The first polishing step S12 is performed as follows. As shown in FIG. 4, a cylindrical jig 40 is brought into contact with the flange surface 31 which has been subjected to the turning process, and the annular surface 19 is polished. In the present embodiment, simultaneously with the polishing process of the annular surface 19 including the annular sealing surface 29a, the outer peripheral surface 33 of the shaft portion 26 including the rounded surface 29c, the cylindrical sealing surface 29b, and the shaft raceway surface 11a The polishing process (except for the surface 34) is performed. That is, the peripheral surface 33 including the annular surface 19 including the annular sealing surface 29a, the rounded surface 29c, the cylindrical sealing surface 29b, and the shaft raceway surface 11a (but with a small diameter outer periphery) The polishing process (except for the surface 34) is performed.

  The jig 40 receives a reaction force in the polishing process. In the present embodiment, the turned flange surface 31 is the reference surface, and the annular surface 19 and the like are polished. At this time, the bolt 28 is not attached to the bolt hole 32. The annular surface 19 is turned in the turning process S11 as described above, and is polished in the first polishing process S12. For this reason, on the annular surface 19, the turning process of the turning process S11 is "primary process", and the polishing process of the first polishing process S12 is "secondary process".

  In the first polishing step S12, the polishing process may be performed a plurality of times on the annular surface 19 or the like. That is, as secondary processing of the annular surface 19 or the like, for example, the polishing process may be performed in a plurality of steps, divided into rough polishing process and finish polishing process.

  The press-in step S13 is performed as follows. A plurality of bolt holes 32 are provided at equal intervals along the circumferential direction. The bolts 28 are press-fit into all the bolt holes 32. The bolts 28 are attached to the bolt holes 32 with a margin. For this reason, the circumference of the bolt hole 32 is particularly distorted, and a shake occurs on the flange surface 31. Since a plurality of bolt holes 32 are provided along the circumferential direction (see FIG. 7), the runout has a corrugated shape of unevenness of a minute height along the circumferential direction. In addition, due to the press-fitting of the bolt 32, the same swing may occur in the annular surface 19. FIG. 5 is a schematic view for explaining the deflection (distortion) of the annular surface 19 (annular seal surface 29a). The annular surface 19 has a corrugated shape of asperities with a small height.

  The second polishing step S14 is performed as follows. As shown in FIG. 6, a cylindrical jig 41 is brought into contact with the radially outer second annular region K2 of the polished annular surface 19, and the flange surface 31 is polished. The jig 41 receives a reaction force in the polishing process. At this time, the bolt 28 is attached to the bolt hole 32. By the second polishing step S14, the swing of the flange surface 31 is eliminated. In this polishing process, the flange surface 31 is precisely polished because the annular surface 19 which is the polishing surface is used as a reference. In the second polishing step S14, the polishing process on the flange surface 31 may be performed a plurality of times.

  As shown in FIG. 6, when polishing of the flange surface 31 is performed in a state where the cylindrical jig 41 is in contact with the second annular region K2 of the annular surface 19 which is a polishing surface, the annular surface 19 (second Slippage occurs between the annular region K2) and the jig 41. As a result, rubbing marks may occur in the second annular region K2. As described above, the press-in of the bolt 28 generates a swing on the annular surface 19 (see FIG. 5). This runout has a corrugated shape of unevenness of minute height along the circumferential direction. Therefore, in the second annular region K2, a scuff mark is attached to the wave-like convex portion. In FIG. 5, the area to which the rubbing marks are attached is denoted by a symbol Q. On the other hand, as shown in FIG. 6, the jig 41 does not contact the radially inner first annular region K1 of the annular surface 19 which is the polishing surface. For this reason, a scratch does not occur in the first annular region K1.

  As described above, in the second polishing step S14, the first annular region K1 to be a part (the annular seal surface 29a) of the seal surface 29 on the radially inward side of the annular surface 19 is opened. The flange surface 31 is polished in a state in which the cylindrical jig 41 is in contact with the second annular region K2. In this embodiment, as shown in FIG. 7, an imaginary circle (two-dot chain line L) having a diameter D2 equal to or more than a value obtained by adding 10 mm to the outer diameter D1 of the cylindrical sealing surface 29b of the sealing surface 29. And a boundary between the first annular region K1 and the second annular region K2. The jig 41 strikes the second annular region K2 provided on the outer side in the radial direction of the boundary (two-dot chain line L).

[Assembly process]
In FIG. 2, in the assembly step S <b> 20, the elements manufactured through the manufacturing step S <b> 10 are assembled. In FIG. 1, the inner ring 24 is fitted to the small diameter portion 39 on the other side in the axial direction of the hub axle 23 manufactured by the hub axle manufacturing process, and caulks (plastically deforms) the end 23 a of the hub axle 23. Thereby, the inner shaft member 11 is obtained. The assembling process is the same as the conventional method, and the description is omitted here. In the assembly process, the inner shaft member 11 having the hub shaft 23 manufactured by the hub shaft manufacturing process, the outer ring member 12, the rolling element 13, and the seals 15 and 16 are combined. Thus, the wheel bearing device 10 is completed.

[About this embodiment]
According to the above manufacturing method, as shown in FIG. 6, after the bolt 28 is pressed into the bolt hole 32 of the flange portion 27, the flange surface 31 is polished. For this reason, the runout of the flange surface 31 can be suppressed. Polishing of the flange surface 31 is performed using the annular surface 19 as a reference surface. However, in this case, the cylindrical jig 41 is not in contact with the radially inward first annular region K1 but in a state in which the cylindrical jig 41 is in contact with the radially outward second annular region K2. As described above, the first annular region K1 is the annular sealing surface 29a which is a part of the sealing surface 29 (see FIG. 1). As a result, no rub marks are left on the sealing surface 29.

  The wheel bearing device 10 obtained by this manufacturing method is as follows. In FIG. 1, the flange surface 31 on one side in the axial direction of the flange portion 27 is a polished surface, and deflection of the flange surface 31 is suppressed. The flange surface 31 is a polished surface having a uniform surface condition along the circumferential direction. Then, on the other side in the axial direction of the flange portion 27, the radially inner first annular region K1 of the annular surface 19 is a polished surface that becomes a part of the sealing surface 29 (annular sealing surface 29a). The radially outer second annular region K2 of the annular surface 19 is a polished surface having a surface state different from that of the sealing surface 29 (annular sealing surface 29a).

  The reason why the surface state is different in the second annular region K2 compared to the first annular region K1 is as follows. That is, as shown in FIG. 6, while the jig 41 contacts the second annular area K2, the jig 41 does not contact in the first annular area K1. The jig 41 is in contact with the second annular region K2, and when the flange surface 31 is polished, a slip occurs between the jig 41 and the annular surface 19. For this reason, rubbing marks (scratches) occur in the second annular region K2. In the rubbed area, the surface roughness (average value) is different (higher) from that of the first annular area K1, and the gloss is reduced. On the other hand, in the first annular region K1, since the jig 41 is not in contact, the surface condition (glossy, surface roughness) is uniform along the circumferential direction.

  From the above, no rubbing marks are generated on the sealing surface 29, particularly the annular sealing surface 29a. For this reason, in the wheel bearing device 10 obtained by the manufacturing method of the present embodiment, it is possible to improve the sealing performance in the sealing structure on one side in the axial direction constituted by the sealing surface 29 and the first seal 15 Become. In addition, as shown in FIG. 5, since the bolt 28 is press-fit into the bolt hole 32, the lip 30a of the seal 15 (FIG. 1) even if the entire annular surface 19 including the annular sealing surface 29a is shaken. Can be elastically deformed to follow the annular sealing surface 29a. For this reason, sealing performance is secured. Further, since the seal surface 29 (annular seal surface 29a) is a polished surface, the seal performance is high.

  The embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is not limited to the embodiments described above, and includes all modifications within the scope equivalent to the configurations described in the scope of the claims.

10: bearing device for wheel 11: inner shaft member 12: outer ring member 13: rolling element 15: first seal 19: annular surface 23: hub shaft 26: shaft portion 27: flange portion 28: bolt 29: seal surface 30a : Lip 31: flange surface 32: bolt hole 41: jig K1: first annular area K2: second annular area

Claims (4)

Cylindrical outer ring member,
A shaft body portion provided radially inward of the outer ring member, and a flange portion provided on one axial side of the shaft body portion, and between the shaft body portion and the flange portion Inner shaft member having a hub shaft provided with a sealing surface,
A rolling element disposed between the outer ring member and the inner shaft member;
And a seal having a lip attached to one axial side of the outer ring member and in contact with the sealing surface,
The above-mentioned flange part has a flange surface on one side in the axial direction, a bolt hole penetrating the flange part in the axial direction, and a bearing apparatus for a wheel having an annular surface on the other side in the axial direction including a part of the sealing surface. Manufacturing method of
A hub shaft manufacturing step, and an assembling step of combining the inner shaft member having the hub shaft manufactured by the hub shaft manufacturing step, the outer ring member, the rolling element, and the seal;
The hub axle manufacturing process
A turning process for turning the flange surface and turning the annular surface;
A first polishing process for polishing the annular surface;
A press-fitting step of pressing a bolt into the bolt hole;
And, after the press-in step, a second polishing step of polishing the flange surface using the ground annular surface as a reference surface,
In the second polishing step, a first annular region, which is the part of the sealing surface on the radially inward side, of the annular surface is opened to form a cylindrical shape in the second annular region on the radially outer side. The manufacturing method of the bearing apparatus for wheels which grind-processes the said flange surface in the state which applied the tool. The sealing surface includes a part of an outer peripheral surface on one side in the axial direction of the shaft portion,
An imaginary circle having a diameter equal to or more than a value obtained by adding 10 mm to the outer diameter of a part of the outer peripheral surface is used as a boundary between the first annular region and the second annular region. The manufacturing method of the bearing apparatus for wheels of Claim 1 which strikes. Cylindrical outer ring member,
A shaft body portion provided radially inward of the outer ring member, and a flange portion provided on one axial side of the shaft body portion, and between the shaft body portion and the flange portion Inner shaft member having a hub shaft provided with a sealing surface,
A rolling element disposed between the outer ring member and the inner shaft member;
And a seal having a lip attached to one axial side of the outer ring member and in contact with the sealing surface,
The flange portion has a flange surface on one side in the axial direction, a bolt press-fitted into a bolt hole penetrating the flange portion in the axial direction, and an annular surface on the other side in the axial direction including a part of the sealing surface. Have
The flange surface is a polished surface,
The radially inner first annular region of the annular surfaces is a polished surface that becomes a part of the sealing surface,
The wheel bearing apparatus, wherein the radially outer second annular region of the annular surfaces is a polished surface having a surface condition different from that of the sealing surface. A part of the outer peripheral surface on one side in the axial direction of the shaft portion is a polished surface that is continuous with the part of the sealing surface,
The boundary between the first annular region and the second annular region is located on a virtual circle having a diameter equal to or greater than a value obtained by adding 10 mm to the outer diameter of a part of the outer peripheral surface. Bearing device for wheels as described.

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