JP2002370104A - Bearing unit for wheel and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the judder generated in braking by improving the perpendicularity of an outer face of a rotation-side flange 13a against a center of the rotation of a hub 8b. SOLUTION: Finishing work of the outer face of the rotation-side flange 13a is performed by turning work in a state of rotating the hub 8b after components of this bearing unit 5b for a wheel are assembled. The subject of this invention can be achieved by preventing the perpendicularity from being affected by dimensional error and assembling error of each component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel bearing unit for supporting a wheel of a motor vehicle and a rotating body for braking such as a rotor or a drum, and to an improvement of a method of manufacturing such a wheel bearing unit.

[0002]

2. Description of the Related Art A wheel 1 constituting a wheel of an automobile and a rotor 2 constituting a disc brake which is a braking device.
Is rotatably supported on a knuckle 3 constituting a suspension device, for example, by a structure as shown in FIG. That is, the outer ring 6, which is a stationary member, which constitutes the wheel bearing unit 5 to which the present invention is applied, is fixed to the circular support hole 4 formed in the knuckle 3 by a plurality of bolts 7. On the other hand, the hub 8 constituting the wheel bearing unit 5
The wheel 1 and the rotor 2 are connected to a plurality of studs 9.
And the nut 10 for connection and fixation.

The inner race of the outer race 6 has a double row outer raceway 1
1a and 11b are formed, and a fixed-side flange 12 is formed on the outer peripheral surface. Such an outer ring 6 is fixed to the knuckle 3 by connecting the fixed side flange 12 to the knuckle 3 with the bolts 7.

On the other hand, a part of the outer peripheral surface of the hub 8 is an outer end opening of the outer race 6 (the term "outside in the axial direction" means a part which is outward in the width direction when assembled to an automobile,
The left side of FIGS. 1, 2, 5, and 6, the upper side of FIGS. Conversely, when it is assembled to a car, it is located at the center in the width direction.
The right side of 2, 5, 6 and the lower side of FIGS. 4, 7 are referred to as inner in the axial direction. The portion protruding from ()) is formed with a rotating flange 13. The wheel 1 and the rotor 2 are provided on one side (the outer side in the illustrated example) of the rotating flange 13.
Then, the above-mentioned studs 9 and nuts 10 are connected and fixed. Also, on the outer peripheral surface of the intermediate portion of the hub 8, the outer raceway 11 of the outer row of the double row outer raceways 11a and 11b
An inner raceway 14a is formed in a portion opposing a. Further, a rotating member 23 is formed together with the hub 8 on the small-diameter stepped portion 15 formed on the outer peripheral surface of the inner end of the hub 8.
The inner ring 16 is externally fitted and fixed. The inner raceway 14b formed on the outer peripheral surface of the inner race 16 is opposed to the inner raceway 11b of the double row outer raceways 11a and 11b.

[0005] Between each of the outer raceways 11a, 11b and each of the inner raceways 14a, 14b, a plurality of balls 17, 17 each of which is a rolling element, is provided with a plurality of cages 18, 1 respectively.
8 so that it can roll freely. With this configuration, a double-row angular contact type ball bearing as a rear combination is formed, and the rotating member 23 is provided inside the outer ring 6.
Are supported rotatably and capable of supporting radial loads and thrust loads. A seal ring 19 is provided between the inner peripheral surface of both ends of the outer ring 6, the outer peripheral surface of the intermediate portion of the hub 8 and the outer peripheral surface of the inner end of the inner ring 16.
a, 19b are provided to block the interior space where the balls 17, 17 are provided from the outside. Further, the illustrated example is a wheel bearing unit 5 for drive wheels (rear wheels of FR and RR vehicles, front wheels of FF vehicles, all wheels of 4WD vehicles). A hole 20 is formed. The spline shaft 22 of the constant velocity joint 21 is inserted into the spline hole 20. Although not shown, the wheel bearing units for the non-drive wheels (the front wheels of the FR and RR vehicles, the rear wheels of the FF vehicle) include not only the inner-wheel rotating type as shown but also the outer-wheel rotating type. There are also things.

When the above-described wheel bearing unit 5 is used, the outer ring 6 is fixed to the knuckle 3 as shown in FIG. And the rotor 2 is fixed. The rotor 2 is combined with a support and a caliper (not shown) fixed to the knuckle 3 to form a disc brake for braking. At the time of braking, a pair of pads provided so as to sandwich the rotor 2 is pressed against both side surfaces of the rotor 2 which are friction surfaces for braking. still,
In the present specification, the friction surface for braking refers to both axial side surfaces of the rotor when the braking rotary body is a rotor, and when the braking rotary body is a drum, the inside of the drum is used. Say the circumference.

[0007] On the other hand, it is known that vibrations accompanied by unpleasant noise, often called judder, are generated when braking an automobile. There are various known causes of such vibrations, such as uneven friction between the side surface of the rotor 2 and the lining of the pad. However, it is known that the runout of the rotor 2 is also a major cause. Have been. That is, this rotor 2
Should be at right angles to the rotation center of the rotor 2, but it is difficult to make it completely at right angles due to inevitable manufacturing errors and the like. As a result, it is inevitable that the side surface of the rotor 2 swings in the direction of the rotation axis (the left-right direction in FIG. 6) when the vehicle is running. When such shake (the amount of displacement in the left-right direction in FIG. 6) increases,
When the lining of a pair of pads is pressed against both side surfaces of the rotor 2 for braking, the judder is generated.
When a drum constituting a drum brake is fixed to the side surface of the rotating side flange 13 and the inner peripheral surface of the drum is not completely parallel to the rotation center of the drum, the shoe is attached to the inner peripheral surface. When pressed, vibration like judder also occurs.

In order to suppress the judder generated due to such a cause, it is necessary to suppress (improve) the axial runout (axial runout) of the side surface of the rotor 2 or the radial runout of the inner peripheral surface of the drum. Is important. Then, in order to suppress this run-out, the mounting surface of the rotation side flange 13 with respect to the rotation center of the hub 8 (one side surface of the rotation side flange 13)
It is important to improve the squareness of the object. U.S. Pat. No. 6,071,180 discloses that this rotary side flange 13
A method for manufacturing a bearing unit for a wheel for improving the perpendicularity of the mounting surface is described.

In the case of the method of manufacturing the wheel bearing unit 5a described in the above-mentioned US patent specification, as shown in FIGS. 7 and 8, one side surface 26 of the rotating flange 13a provided on the outer peripheral surface of the hub 8a is fixed. When processing to the shape and dimensions of the above, first, each component member of the wheel bearing unit 5a including the hub 8a before processing the one side surface 26 is assembled. Next, after fixing the fixed flange 12 provided on the outer peripheral surface of the outer ring 6 to the support stand 24 of the processing apparatus, the spindle 8 rotates the hub 8 a while rotating the hub 8 a.
The tip end surface of the grindstone 27 is brought into contact with one side surface 26 of 3a, and this one side surface 26 is finished to a predetermined shape and dimensions. When a wheel bearing unit is manufactured by such a method,
Regardless of dimensional errors and assembly errors inevitable in manufacturing each component, the one side surface 2 with respect to the rotation center of the hub 8a.
6 can be improved, and the vibration of the braking friction surface of the rotary brake such as the rotor 2 (see FIG. 6) fixed to the one side surface 26 can be suppressed.

[0010]

In the method of manufacturing a bearing unit for a wheel described in the above-mentioned U.S. Pat. No. 6,071,180, the finishing of the one side surface 26 of the rotary flange 13a is performed by a grindstone. 27, it is difficult to ensure sufficient quality of the wheel bearing unit. That is, the grinding is performed by the grinding wheel 27.
Is performed by rotating the grindstone 27 in a state where the grindstone 27 is pressed against the one side surface 26, so that the temperature of the rotating side flange 13a increases during processing. In order to prevent the rotation side flange 13a from being distorted due to the temperature rise, it is necessary to grind the one side surface 26 while supplying the grinding fluid to the portion to be processed.

After assembling the components of the wheel bearing unit 5a, grinding is performed on the one side surface 26 while supplying a grinding fluid, and the grinding fluid installs the tapered rollers 28, 28 as rolling elements. As a result, there is a possibility that the vehicle enters the internal space 29 of the wheel bearing unit 5a. Then, if it enters, the grease sealed in the internal space 29 is deteriorated or the like, thereby deteriorating the durability of the wheel bearing unit. In addition, since fine chips and grindstone powder generated by the grinding process are mixed in the grinding fluid entering the internal space 29, these chips and grindstone powder are rolled on the rolling surfaces of the tapered rollers 28, 28. And outer raceway 11c, 1
1c and the inner ring raceways 14c, 14c, which may cause the durability of the wheel bearing unit 5a to be significantly reduced.

A cup-shaped grindstone 2 as shown in FIGS.
In the case of performing the grinding process on the one side surface 26 according to 7,
The frictional area between the tip surface of the grindstone 27 and the one side surface 26 increases, and the rotational resistance of the grindstone 27 tends to be large and unstable. As a result, there is a possibility that the finishing accuracy of the one side surface 26 cannot always be sufficiently ensured. Also, when a high degree of rotational balance is required, as in a high-performance car,
In some cases, it is required to finish not only one side of the rotating side flange 13a but also the outer peripheral edge.
In the method using the method, the outer peripheral edge cannot be finished as it is. Processing work becomes troublesome.

Further, it is common to press-fit and fix the base ends of the studs 9 and 9 (see FIG. 6) for fixing the wheels and the rotating body for braking to the rotating side flange 13a.
At the time of this press-fitting, the one side surface 26 may be deformed. Regardless of such deformation, in order to secure the accuracy of the one side surface 26, it is conceivable that the finishing process of the one side surface 26 is performed after the studs 9, 9 are press-fitted and fixed. It is difficult to perform the grinding process using the press after the press-fitting and fixing. The wheel bearing unit and the method of manufacturing the same according to the present invention have been made in view of such circumstances.

[0014]

According to the wheel bearing unit of the present invention and the method of manufacturing the same, the wheel bearing unit according to the first aspect of the present invention is the same as the above-described conventional wheel bearing unit, and is a non-rotating stationary unit. Member, a rotating member that rotates together with the wheels, a plurality of rolling elements provided between a stationary track and a rotating track provided on peripheral surfaces of the stationary member and the rotating member facing each other, A rotating flange is provided on the outer peripheral surface of the rotating member, and the braking rotating body and the wheel are fixedly connected to the side surface in a used state. In particular, in the wheel bearing unit according to claim 1, the side surface of the rotating side flange for coupling and fixing the rotating body for braking and the wheel includes at least the stationary member, the rotating member, and the plurality of rolling elements. Is assembled into a predetermined shape and dimensions by turning. Further, a method for manufacturing a wheel bearing unit according to claim 2 is the method for manufacturing a wheel bearing unit according to claim 1, wherein the stationary member, the rotating member, and the plurality of rolling elements are combined. After assembling, while rotating the rotating member with respect to the stationary member, the side surface of the rotating flange is processed into a predetermined shape and dimensions by turning.

[0015]

In the case of the wheel bearing unit and the method of manufacturing the same according to the present invention constructed as described above, after assembling the stationary member, the rotating member, and the plurality of rolling elements, the braking member provided on the outer peripheral surface of the rotating member is provided. The side surface of the rotating flange for connecting and fixing the rotating body for use and the wheel is machined into a predetermined shape and dimensions. For this reason, regardless of dimensional errors and assembly errors that are inevitable in the manufacture of each component, the perpendicularity of the side surface of the rotating flange with respect to the rotation center of the rotating member is increased, and the braking fixed to the rotating flange is performed. The vibration of the friction surface for braking of the rotating body can be suppressed.

Further, in the case of the present invention, since the processing of the side surface of the rotating flange is performed by turning, it is not necessary to pour a grinding fluid into a portion to be processed, and so-called dry processing can be performed. Further, the processing waste generated during the processing becomes continuous in a thread shape, and is hardly scattered around. For this reason, it becomes difficult for foreign substances such as grinding fluid and processing chips to enter the internal space of the wheel bearing unit, and it is difficult to cause a cause of the deterioration of the durability of the wheel bearing unit due to the finishing of the rotating flange. it can. In addition, the frictional force acting between the machining tool and the side surface of the rotating flange during turning is limited, so that the machining can be performed in a stable state,
Distortion hardly occurs in the rotating flange. Furthermore,
If necessary, finishing of the outer peripheral edge of the rotating flange and finishing after press-fitting and fixing the stud can be easily performed.

[0017]

1 to 3 show a first embodiment of the present invention. The wheel bearing unit 5b manufactured by the manufacturing method of the present embodiment is provided with a fixed side flange 12 for connecting and fixing the outer ring 6 to the knuckle 3 (FIG. 6) on the outer peripheral surface of an intermediate portion of the outer ring 6 which is a stationary wheel. I have. Further, double rows of outer raceways 11a and 11b are formed on the inner peripheral surface of the outer race 6. Further, inner ring raceways 14a and 14b are provided on portions of the outer peripheral surfaces of the hub 8b and the inner race 16 that constitute the rotating member 23a and oppose the outer raceways 11a and 11b, respectively. That is, the inner raceway 14a is formed directly on the outer peripheral surface of the intermediate portion of the hub 8b, and the inner raceway 16b is formed with the inner raceway 14b on the outer peripheral surface of the small-diameter step portion 15 formed near the inner end of the hub 8b. Is fitted outside. In order to prevent the inner ring 16 from coming out of the small-diameter stepped portion 15, a caulked portion 30 is formed at the inner end of the hub 8b. That is, the inner ring 16 is attached to the small-diameter step portion 15.
Is externally fitted, the portion protruding from the inner end surface of the inner race 16 at the inner end of the hub 8b is plastically deformed radially outward to form the swaged portion 30, and the swaged portion 30 forms the inner race 16 Of the inner end face. With this configuration, the inner ring 16 is externally fitted and fixed to the inner end of the hub 8b.

A portion near the outer end of the outer peripheral surface of the hub 8b and protruding from the outer end opening of the outer ring 6 includes a wheel 1 constituting a wheel and a rotor 2 which is a rotating body for braking.
(FIG. 6) Or rotating side flange 13 for fixing drum
a is provided. At a plurality of positions in the circumferential direction of the rotation side flange 13a, mounting holes 31 are formed on the same circumference centered on the rotation center of the hub 8b, and a plurality of studs are formed inside each of the mounting holes 31. The serrations provided at the base end of each of 9 are press-fitted and fixed.

Between the outer raceways 11a, 11b and the inner raceways 14a, 14b, a plurality of balls 17, 17 each of which is a rolling element, are provided with a cage 18, 18, respectively.
It is provided so that it can roll freely while being held by. A pair of seal rings 19a and 19b are provided between the inner peripheral surface of both ends of the outer ring 6 and the outer peripheral surface of the intermediate portion of the hub 8b and the inner peripheral portion of the inner ring 16 so as to provide Ball 17,
The interior space 32 provided with 17 is shut off from the outside to prevent leakage of grease sealed in the interior space 32 and to prevent foreign matter from entering the interior space 32.

Further, in the case of this embodiment, the inner seal ring 19 of the pair of seal rings 19a and 19b is used.
The encoder 34 is fixed to a side surface of a core bar 33 which is externally fitted and fixed to the inner end of the inner ring 16. The encoder 34 is made of a rubber magnet in which S poles and N poles are alternately arranged in the circumferential direction. That is, this encoder 3
Reference numeral 4 denotes a ring-shaped rubber magnet formed by mixing ferrite powder in rubber, and is magnetized in the axial direction. The magnetization directions are changed alternately and at equal intervals in the circumferential direction. Therefore, on the inner surface of the encoder 34, S poles and N poles are alternately arranged at equal intervals in the circumferential direction. When the wheel bearing unit 5b is used, a detection unit of a sensor (not shown) supported on a fixed part such as a part of a suspension device is opposed to the inner surface of the encoder 34 via a minute gap. The output signal of the sensor, which changes according to the rotation speed of the encoder 34, can be taken out. Such an encoder 34 and a sensor constitute a rotation speed detecting device for detecting a rotation speed of a wheel fixed to the hub 8b.

The outer surface of the rotating flange 13a provided on the wheel bearing unit 5b as described above is finished by turning to a flat surface perpendicular to the rotation center axis of the hub 8b. Prior to turning on the outer surface of the rotating flange 13a in this manner, the components of the wheel bearing unit 5b are replaced with predetermined shapes and dimensions except for the outer surface of the rotating flange 13a. Process into or,
The outer side surface of the rotating side flange 13a is processed into a rough shape and dimensions. Next, the components of the wheel bearing unit 5b are assembled in the state shown in FIG. That is, the outer raceways 11a, 11 provided on the inner peripheral surface of the outer race 6
b, the outer ring 6, the hub 8b, the inner ring 16, and the plurality of balls 17 in a state where a plurality of balls 17, 17 are provided between the inner ring raceways 14a, 14b provided on the outer peripheral surface of the hub 8b and the inner ring 16; , 17 are assembled. A pair of seal rings 19a, 19b is provided between the inner peripheral surface of both ends of the outer ring 6 and the outer peripheral surface of the intermediate portion of the hub 8b and the outer peripheral surface of the inner end of the inner ring 16.
Is provided. Further, the base ends of the plurality of studs 9 are fixed to the rotating side flange 13a.

Then, in this state, the wheel bearing unit 5b to be turned on the outer side surface of the rotary side flange 13a is assembled to the turning apparatus 35. in this case,
A portion of the outer peripheral surface of the outer ring 6 that is axially inner than the inner side surface of the fixed side flange 12 is gripped by the tip of a chuck 36 that constitutes the turning device 35. In addition, the distal end surface (the left end surface in FIGS. 1 and 2) of the chuck 36 abuts on the inner surface of the fixed side flange 12 near the inner diameter.
In the case of the present example, the inner peripheral surface of the distal end of the chuck 36 is constituted by a sleeve 37 made of a relatively soft material such as synthetic resin, aluminum, or copper. And
When the outer ring 6 is gripped by the chuck 36, the outer peripheral surface of the outer ring 6 contacts only the inner peripheral surface of the sleeve 37 so that the outer peripheral surface of the outer ring 6 is not damaged.

In the case of the present embodiment, the shape of the outer surface of the rotating side flange 13a is set so that the outer surface of the rotating side flange 13a can be easily turned with the respective studs 9 fixed to the rotating side flange 13a. Is devised. That is, in the case of the present embodiment, an annular concave portion 38 is formed over the entire circumference at a radially intermediate portion of the outer surface of the rotating side flange 13a. One end (left end in FIGS. 1 and 2) of the plurality of mounting holes 31 for fixing the base end of each stud 9 is opened in the recess 38. Width W ₃₈ in the radial direction of the recess 38 is larger than the inner diameter d ₃₁ of each mounting hole 31 (FIG. _{2) (W 38> d 31} ). Each stud 9 above
Of the studs 9 with the base end of the rotating flange 13a fixed to the rotating flange 13a.
Part protruding from the outer surface of 3a (part except flange 39)
Exists between an imaginary cylindrical surface including the outer peripheral edge of the concave portion 38 shown by a dashed line α in FIG. 1 and an imaginary cylindrical surface including the inner peripheral edge also shown by a dashed line β. Is a cross section thereof) in a cylindrical virtual space.

Then, the tip of the spindle 40 of the turning device 35 is inserted into the spline hole 20 provided at the center of the hub 8b from the outer end of the hub 8b. The male spline portion 41 provided on the outer peripheral surface and the spline hole 20 are spline-engaged. Next, by rotating the spindle 40, the hub 8b is rotated about its central axis, and the concave portion 3 is formed on the outer surface of the rotary flange 13a.
In the portion sandwiching 8 from both sides in the radial direction (oblique lattice portion in FIG. 3),
Two precision machining tools 42a and 42b are abutted to perform turning on each of these portions. Then, the outer side surface of the rotation side flange 13a is finished to a predetermined shape and dimensions.

As described above, in the case of the method of manufacturing the wheel bearing unit of the present invention and the wheel bearing unit obtained by this manufacturing method, after assembling the components of the wheel bearing unit 5b, the hub 8b is mounted. Wheel 1 provided on the outer peripheral surface
And a rotating side flange 13a for connecting and fixing the rotor 2
Is turned on the outer surface of the to finish it in a predetermined shape and dimensions. For this reason, the perpendicularity of the outer side surface of the rotating side flange 13a with respect to the center of rotation of the hub 8b is increased irrespective of dimensional errors and assembly errors which are inevitable in the manufacture of the respective constituent members. Can be suppressed on both sides of the rotor 2 which is the frictional surface for braking fixed to the rotor 2.

In addition, in the case of the present invention, since the outer surface of the rotary side flange 13a is processed by turning using the precision machining tools 42a and 42b,
There is no need to pour a grinding fluid onto the outer surface of the rotating flange 13a, which is the portion to be processed, and so-called dry processing can be performed.
Further, the processing waste generated during the processing becomes continuous in a thread shape, and is hardly scattered around. For this reason, it becomes difficult for foreign substances such as grinding fluid and processing waste to enter the internal space 32 of the wheel bearing unit 5b, which has already been assembled with the constituent members, and with the finishing of the rotary side flange 13a, A cause that the durability of the wheel bearing unit 5b is impaired can be less likely to occur.

At the time of turning, each of the precision machining tools 42a and 42b, which are machining tools, and the rotating flange 1
The frictional force acting on the outer surface of the member 3a is limited. For this reason, the stress applied to the rotating side flange 13a at the time of machining can be suppressed to be small, and the heat generated at the portion to be processed can be reduced.
a is less likely to be distorted. For this reason, run-out on both side surfaces of the rotor 2 fixed to the rotating side flange 13a can be further reduced. Further, if necessary, finishing of the outer peripheral edge of the rotating flange 13a can be easily performed without attaching / detaching the wheel bearing unit 5b to / from the turning device 35.

Further, in the case of this embodiment, the outer peripheral surface of the outer race 6 is gripped by the chuck 36 of the turning device 35, and the outer peripheral surface of the outer race 6 is formed inside a sleeve 37 made of a relatively soft material. It comes into contact only with the peripheral surface.
A relatively hard metal part constituting the main body of the chuck 36 does not contact the outer peripheral surface of the outer ring 6. For this reason, the outer peripheral surface can be prevented from being damaged by the hard metal portion constituting the chuck 36, and the shape accuracy of the outer peripheral surface of this portion can be sufficiently ensured. The outer peripheral surface of this portion is a portion that is fitted inside the support hole 4 (FIG. 6) of the knuckle 3 when the wheel bearing unit 5b is used, and the accuracy of the outer peripheral surface of this portion can be sufficiently ensured. As a result, a part of the outer ring 6 can be fixed inside the support hole 4 without rattling.

In the case of the present embodiment, an annular concave portion 38 is formed at a radially intermediate portion of the outer side surface of the rotating side flange 13a, and a plurality of mounting holes 31 for fixing the plurality of studs 9 are formed. One end in the axial direction is opened in the recess 38. For this reason, at the time of turning with each precision machining tool 42a, 42b, these precision machining tools 42a, 42b
And studs 9 fixed to the mounting holes 31 can be prevented from interfering with each other. Therefore, the rotation side flange 13a
In the state where the plurality of studs 9 are fixed, the turning work performed on the outer side surface of the rotating side flange 13a can be easily performed. Moreover, on the outer side surface of the rotary side flange 13a, it is possible to perform turning on almost all of the portion sandwiching the concave portion 38 from both sides in the radial direction. For this reason, it is possible to eliminate the formation of a protruding portion that protrudes outward in the axial direction from the part subjected to the turning process on a part of the outer side surface of the rotating flange 13a. Therefore, almost all portions of the outer surface deviating from the recesses 38 can be made flat, and the runout of the rotor 2 fixed to the outer surface can be sufficiently suppressed.

In the first example described above, if the finishing of the outer side surface of the rotary side flange 13a is performed before the stud 9 is press-fitted and fixed to the rotary side flange 13a, the rotary side flange 13a may be used. 13a from the outer surface of the recess 3
8 can be omitted, and a finishing process can be continuously performed on this outer surface with one precision machining bit. Further, when the finishing process of the outer surface is performed after the press-fitting and fixing of the stud 9, the processing time is slightly increased, but the finishing process can be performed by one precision working bit. Even in this case, if the NC control is performed, the surface positions of the outer diameter side and the inner diameter side of the concave portion 38 can be strictly matched.

FIG. 4 shows a second embodiment of the present invention.
An example is shown. In the case of this example, the finishing of the outer surface of the rotating flange 13a constituting the wheel bearing unit 5c is performed before the stud is press-fitted and fixed to the rotating flange 13a as described above. . For this reason, in the case of this example, the concave portion 38 (FIGS. 1 and 2) as in the above-described first example is not formed on the outer side surface of the rotating side flange 13a. Further, the wheel bearing unit 5c is assembled to a turning device 35a so that the outer surface is continuously machined by one precision machining tool 42c. In this case, the outer race 6 is supported and fixed on the support base 24a with its central axis positioned in the vertical direction.
a at the outer end of the hub 8c.
In addition, it is adapted to be fitted inside so as to be able to transmit torque. Further, the inner end of the inner race 16 externally fitted and fixed to the inner end of the hub 8c is made to protrude beyond the inner end surface of the hub 8c, and the inner end surface of the inner race 16 is suppressed by a part of a constant velocity joint (not shown). I am doing it. Further, the encoder as in the first example is not incorporated in the seal ring 19b for closing the inner end opening of the internal space 32. Other configurations and operations are the same as those of the above-described first example, and thus redundant description will be omitted.

The above description has been made in the case where the present invention is applied to a structure in which the base end of the stud 9 is press-fitted and fixed to the rotary side flange 13a. The present invention is not limited to the simple structure, and can be implemented with a structure as shown in FIG. That is, a screw hole 43 for screwing the bolt 44 is formed in the rotating side flange 13b, and a braking rotating member such as the rotor 2 and the wheel 1 are formed in the rotating side flange 13b.
When connecting and fixing the bolts, there is also known a structure in which the bolt 44 passing through the rotating member for braking and the wheel 1 is screwed into the screw hole 43 and further tightened. When the present invention is implemented with such a structure, the concave portion 38 as shown in FIGS. 1 to 3 is not necessary, and one turning tool such as a precision cutting tool used for turning is also required. Can perform continuous machining.

[0033]

The wheel bearing unit and the method of manufacturing the same according to the present invention are constructed and operated as described above. Therefore, unpleasant noise and vibration generated during braking can be sufficiently suppressed at a low cost, and the wheel bearing unit can be manufactured at low cost. The durability of the bearing unit can be sufficiently ensured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first example of an embodiment of the present invention in a state where turning is performed on a side surface of a rotating flange.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a view of the hub as viewed from the left in FIG. 1 omitting a spindle for rotationally driving the hub.

FIG. 4 is a view similar to FIG. 1, showing a second example of the embodiment of the present invention.

FIG. 5 is a partial sectional view showing the third example.

FIG. 6 is a sectional view showing an example of an assembled state of a wheel bearing unit to which the present invention is applied.

FIG. 7 is a partial cross-sectional view showing an example of a conventional structure in a state in which a side surface of a rotating flange is subjected to grinding.

FIG. 8 is a view as viewed from above in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wheel 2 Rotor 3 Knuckle 4 Support hole 5, 5a, 5b, 5c Wheel bearing unit 6 Outer ring 7 Bolt 8, 8a, 8b, 8c Hub 9 Stud 10 Nut 11a, 11b, 11c Outer ring track 12 Fixed side flange 13, 13a , 13b Rotation side flange 14a, 14b, 14c Inner ring raceway 15 Small diameter step 16 Inner ring 17 Ball 18 Retainer 19a, 19b Seal ring 20 Spline hole 21 Constant velocity joint 22 Spline shaft 23, 23a Rotating member 24, 24a Support 25 spindle 26 One side surface 27 Grinding stone 28 Tapered roller 29 Internal space 30 Caulked portion 31 Mounting hole 32 Internal space 33 Core bar 34 Encoder 35, 35a Turning device 36 Chuck 37 Sleeve 38 Recess 39 Flange 40, 40a Spindle 41 Male spline 42a, 42b, 42c Precision machining tool 43 Screw hole 44 Bolt 45 Cylindrical part

Claims (2)

[Claims] 1. A stationary member which does not rotate, a rotating member which rotates together with a wheel, and a stationary member provided between a stationary member and a rotating member provided on peripheral surfaces of the stationary member and the rotating member facing each other. In a wheel bearing unit provided with a plurality of rolling elements and a rotating side flange provided on an outer peripheral surface of the rotating member and connecting and fixing a rotating body for braking and a wheel to a side surface in a use state, The side of the rotating flange is
A bearing unit for a wheel, wherein at least the stationary member, the rotating member, and the plurality of rolling elements are assembled and then processed into a predetermined shape and dimensions by turning. 2. The method for manufacturing a bearing unit for a wheel according to claim 1, wherein after assembling the stationary member, the rotating member, and the plurality of rolling elements, the rotating member is rotated with respect to the stationary member. A method of manufacturing a bearing unit for a wheel, wherein a side surface of a rotating flange is processed into a predetermined shape and dimensions by turning.