JP2002347402A - Bearing unit for wheel and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inexpensively structure capable of preventing the judder in braking. SOLUTION: A notch 30 whose cross section forms an arc shape is formed at a part of the external peripheral face of an outer ring 6. In a state assembling a bearing unit 5a for wheels, the outside face of the rotation side flange 13 of which is to be turned, the outside face of the rotation side flange 13 is turned with a hub 8a rotated in relation to the outer ring 6. With the phase of a mounting hole 24 provided in the rotation side flange 13, and that of the notch 30 coinciding with each other, the bearing unit 5a for wheels is secured in an automatic assembling device. With a stud 26 arranged inside the rotation side flange 13 in the axial direction coaxially with the mounting hole 24, a load is applied to the stud 26 to insert a part of the stud 26 except for a head section 31 into the mounting hole 24 in the axial direction of the mounting hole 24.

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 in 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 by a structure as shown in FIG. 8, for example. That is, the outer ring 6 that constitutes the wheel bearing unit 5 that is the subject of the present invention is fitted to the circular support hole 4 formed in the knuckle 3.
It is fixed by a plurality of bolts 7. On the other hand, the wheel 1 and the rotor 2 are connected and fixed to a hub 8 constituting the wheel bearing unit 5 by a plurality of studs 9 and nuts 10.

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,
Left side of FIGS. Conversely, the right side of FIGS. 1, 4, and 8, which is the center in the width direction when assembled to an automobile, is referred to as the inner side in the axial direction. The portion protruding from ()) is formed with a rotating flange 13. The wheel 1 and the rotor 2 are fixedly connected to one side surface (outside surface in the illustrated example) of the rotating flange 13 by the studs 9 and the nuts 10. A male serration portion 34 is formed on the outer peripheral surface of the base end portion of the stud 9, and the male serration portion 34 is formed in the mounting hole 24 provided in the rotation side flange 13 from the inside in the axial direction to the outside in the axial direction. By press-fitting, each of the studs 9 is fixedly connected to the rotating flange 13. An inner ring raceway 14a is formed on the outer peripheral surface of the intermediate portion of the hub 8 at a portion facing the outer raceway 11a outside the double row outer raceways 11a and 11b. Further, an inner ring 16, which constitutes a rotating member 23 together with the hub 8, is externally fixed to a small-diameter stepped portion 15 formed on the outer peripheral surface of the inner end of the hub 8. And this inner ring 1
The inner raceway 14b formed on the outer peripheral surface of the outer raceway 6 is opposed to the inner outer 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.

When the above-described rolling bearing unit 5 for a wheel is used, as shown in FIG. 8, the outer ring 6 is fixed to the knuckle 3 and a wheel (not shown) is combined with the rotating flange 13 of the hub 8 and a tire (not shown). 1 and a rotor 2 as a rotating body for braking are fixed. Also, rotor 2 of these
And a support and 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. In the present specification, the braking friction surface means both axial sides of the rotor when the braking rotary body is a rotor, and when the braking rotary body is a drum constituting a drum brake. Refers to the inner peripheral surface of this drum.

[0007] On the other hand, it is known that vibrations accompanied by unpleasant noise, often called judder, are often 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 unavoidable that the side surface of the rotor 2 swings in the direction of the rotation axis (the left-right direction in FIG. 8) when the vehicle is running. When such shake (the amount of displacement in the left-right direction in FIG. 8) 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.
Further, when a drum constituting a drum brake is fixed to the side surface of the rotating side flange 13, unless the inner peripheral surface of the drum is completely parallel to the rotation center of the drum,
When the shoe is pressed against the inner peripheral surface of the drum, vibration like a judder also occurs.

In order to suppress the judder generated due to such a cause, 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 suppressed (improved). Things matter. In order to suppress the run-out, it is important to improve the perpendicularity of the mounting surface of the rotating flange 13 (one side surface of the rotating flange 13) to the center of rotation of the hub 8. U.S. Pat. No. 6,071,180 describes a method of manufacturing a wheel bearing unit for improving the perpendicularity of the mounting surface of the rotating flange 13. In the case of the method of manufacturing a bearing unit for a wheel described in this specification, when processing one side surface of a rotating flange provided on an outer peripheral surface of a hub into a predetermined shape and dimensions, first, the one side surface is processed. Assemble the components of the wheel bearing unit, including the front hub. Then, after fixing the fixed side flange provided on the outer peripheral surface of the outer ring to a part of the processing device, while rotating the hub by a spindle, grinding the one side of the rotating side flange provided on the outer peripheral surface of the hub. The one side is finished to a predetermined shape and dimensions by abutting a tool. When the wheel bearing unit is manufactured by such a method, the right angle of one side of the rotation side flange with respect to the rotation center of the hub is improved irrespective of dimensional errors and assembly errors inevitable in manufacturing each component. The vibration of the rotary brake such as the rotor fixed to one side can be suppressed.

[0009]

In the method of manufacturing a bearing unit for a wheel described in the above-mentioned US Pat. No. 6,071,180, a wheel and a rotor are fixed to one side of the rotating flange. There is no particular idea about the structure for this. However, when an actual wheel bearing unit is used, in order to fix the wheel and the rotor on one side surface of the rotating flange, as in the case of the conventional structure shown in FIG. It is necessary to connect the base ends of the studs 9, 9 at a plurality of locations in the circumferential direction. Then, the wheel 1 and the rotor 2 are fixed to one side surface of the rotating flange 13 by the plurality of studs 9 and the plurality of nuts 10 and 10 connected to the tips of the studs 9 and 9. .

However, as in the method of manufacturing a bearing unit for a wheel described in the above-mentioned US Patent Specification, after assembling the components of the bearing unit for a wheel, one side surface of the rotating flange is subjected to grinding or the like. In the case of finishing to the shape and dimensions of the above, there is a possibility that the work of connecting each stud to the rotating side flange becomes considerably troublesome. That is, in the case of the conventional structure, it has not been considered that the respective studs are connected to the rotating flange after assembling the constituent members of the wheel bearing unit. For this reason, in the case of the conventional structure, in general, the stud is fixed to the mounting hole provided in the rotation side flange, and the outer peripheral surface of the head of the stud is extended inward in the axial direction. The surface and a part of the outer ring such as the fixed side flange interfere with each other. In particular, in a structure in which the dimensions of the wheel bearing unit are not particularly increased and the thickness of the outer ring in the radial direction is sufficiently ensured, the virtual cylindrical surface and a part of the outer ring easily interfere with each other. In this case, the studs cannot be inserted into the mounting holes from the axial inner ends of the mounting holes in the axial direction of the mounting holes. For this reason, not only the work of connecting each stud to the rotating flange is considerably troublesome, but also it becomes difficult to automate the work of connecting each stud to the rotating flange by an automatic assembly device or the like. Then, the cost required for manufacturing the wheel bearing unit is increased.

On the other hand, after fixing the base end of each of the studs to the rotating side flange, assembling each component member of the wheel bearing unit including the rotating side flange, and then attaching one end of the rotating side flange. It is also conceivable to finish the side. In this case, however, it is necessary to finish one side of the rotating flange while avoiding a portion of each of the studs protruding from one side of the rotating flange. Since such finishing is considerably troublesome, the cost required for manufacturing the wheel bearing unit also increases. The wheel bearing unit and the method of manufacturing the same according to the present invention have been made in view of such circumstances.

[0012]

In the wheel bearing unit and the method of manufacturing the same according to the present invention, the wheel bearing unit according to the first aspect of the present invention has an outer peripheral surface similar to the above-described conventional wheel bearing unit. An outer ring having a fixed side flange for fixing to a vehicle body, an outer raceway on an inner peripheral surface, and not rotating even when used; a rotating member having an inner raceway on an outer peripheral surface, rotating during use; A plurality of rolling elements provided between a raceway and the outer raceway, and rotations provided on an outer peripheral surface of an outer end portion of the rotating member to couple and fix a braking rotary body and wheels to side surfaces thereof in use. And a side flange.

[0013] In particular, in the bearing unit for a wheel according to the first aspect, a mounting hole formed in a part of the rotating side flange is coupled to the rotating side flange while being inserted into the mounting hole. A fixed stud; and a notch formed on a part of an outer peripheral surface of at least one of the outer race and the stud. Then, after assembling the outer race, the rotating member, and the plurality of rolling elements, the stud is processed into a predetermined shape and dimensions on the side surface of the rotating flange, and then the notch is formed around the outer periphery of the stud or the outer race. This is inserted into the mounting hole from the axially inner end side of the mounting hole while being aligned with the surface, and is fixedly connected to the rotating flange.

Further, a method of manufacturing a wheel bearing unit according to a second aspect is the method of manufacturing a wheel bearing unit according to the first aspect, wherein the outer ring, a rotating member, and a plurality of rolling elements are assembled. Then, while rotating the rotating member with respect to the outer ring, a side surface of a rotating flange for coupling and fixing the rotating body for braking and the wheel is processed into a predetermined shape and dimensions, and then the notch is removed from the stud. Alternatively, the stud is inserted into the mounting hole from the axial inner end side of the mounting hole while being aligned with the outer peripheral surface of the outer ring, and the stud is connected and fixed to the rotating flange.

[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 outer ring, the rotating member and the plurality of rolling elements, the braking unit is provided on the outer peripheral surface of the rotating member. The side surface of the rotating side flange for connecting and fixing the rotating body and the wheel is processed into a predetermined shape and dimensions. For this reason, irrespective 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 swing of the rotating body can be suppressed. Moreover, in the case of the present invention, after the side surface of the rotary flange is processed into a predetermined shape and dimensions, a stud is connected and fixed to the rotary side flange. I can do it. When the stud is fixedly connected to the rotating flange, the stud can be inserted into the mounting hole in the axial direction of the mounting hole. For this reason, the operation of connecting the stud to the rotating flange can be easily performed, and the cost required for the manufacturing operation of the wheel bearing unit can be reduced. Further, according to the present invention, the work of connecting the stud to the rotating flange can be automated by an automatic assembling apparatus or the like, and the cost required for the manufacturing operation of the wheel bearing unit can be further reduced. Moreover, in the case of the present invention, a notch is formed in a part of an outer peripheral surface of at least one of the outer ring and the stud, and the notch is inserted into the mounting hole when the stud is inserted. Since it is aligned with the outer peripheral surface of the stud or the outer ring, the size of the wheel bearing unit is not particularly increased, and the radial thickness of the outer ring can be sufficiently ensured.

[0016]

1 to 3 show a first embodiment of the present invention. The wheel bearing unit 5a 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. 8) on the outer peripheral surface of an intermediate portion of the outer ring 6. Further, double rows of outer raceways 11a and 11b are formed on the inner peripheral surface of the outer race 6. Then, a part of the outer peripheral surface of the intermediate part of the outer ring 6 which is displaced inward in the axial direction from the inner side surface of the fixed side flange 12 is fitted into the support hole 4 (FIG. 8) provided in the knuckle 3. A cylindrical surface portion 32 is formed.

The outer raceways 11a, 11b are formed on the outer peripheral surfaces of the hub 8a and the inner race 16 constituting the rotating member 23a.
Are provided with inner raceways 14a and 14b, respectively. That is, the inner raceway 14a is formed directly on the outer peripheral surface of the intermediate portion of the hub 8a, and the inner race 16 having the inner raceway 14b formed on the outer peripheral surface thereof is formed on the small-diameter step portion 15 formed near the inner end of the hub 8a. It is fitted outside. In order to prevent the inner ring 16 from coming out of the small-diameter stepped portion 15, a caulked portion 25 is formed at the inner end of the hub 8a. That is, the inner ring 16 is attached to the small-diameter step portion 15.
Is externally fitted, a portion protruding from the inner end surface of the inner ring 16 at the inner end of the hub 8a is plastically deformed radially outward to form the caulked portion 25, and the caulked portion 25 causes the inner ring 16 to be formed. Of the inner end face. With this configuration, the inner race 16 is externally fitted and fixed to the inner end of the hub 8a.

A portion near the outer end of the outer peripheral surface of the hub 8a and protruding from the outer end opening of the outer ring 6 includes a wheel 1 constituting a wheel and a rotor 2 serving as a rotating body for braking.
(FIG. 8) or rotating flange 13 for fixing drum
Is provided. At a plurality of positions in the circumferential direction of the rotating side flange 13, mounting holes 24 are respectively formed on the same circumference around the rotation center of the hub 8 a, and a plurality of studs are provided inside each of the mounting holes 24. 26 are press-fitted and fixed at their base ends.

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 8a and the inner peripheral portion of the inner ring 16 to provide each of the above-mentioned seal rings. Ball 17,
The interior space 27 having the interior 17 is isolated from the outside to prevent the grease sealed in the interior space 27 from leaking and to prevent foreign matter from entering the interior space 27.

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 29 is fixed to the side surface of the core 28 externally fitted and fixed to the inner end of the inner ring 16. The encoder 29 is made of a rubber magnet in which S poles and N poles are alternately arranged in the circumferential direction. That is, this encoder 2
Reference numeral 9 denotes a rubber magnet formed by mixing ferrite powder in rubber into a ring shape, 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 29, S poles and N poles are arranged alternately and at equal intervals in the circumferential direction. When the wheel bearing unit 5a 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 29 via a minute gap. The output signal of the sensor, which changes according to the rotation speed of the encoder 29, can be taken out. Such an encoder 29 and a sensor constitute a rotation speed detecting device for detecting a rotation speed of a wheel fixed to the hub 8a.

In particular, in the case of the present invention, the fixed flange 12 and the cylindrical surface portion 32 provided on the outer peripheral surface of the outer race 6 are provided.
A circular-shaped cutout 30 is formed at one end (right end in FIG. 2) with respect to the front-rear direction of the vehicle when assembled to the vehicle at a part of the circumferential direction of the vehicle.
In the axial direction (FIG. 1)
(Left and right directions, front and back directions in FIGS. 2 and 3). In the case of the present invention, the positions of the cutouts 30 and the mounting holes 24 are regulated in a predetermined relationship described below. First, in a state where the respective constituent members of the wheel bearing unit 5a are assembled, the rotating flange 13 of the outer race 6 is used.
It is assumed that one of the plurality of mounting holes 24, 24 provided in each of the notches 30 and the notch 30 have the same phase in the rotation direction. Then, it is assumed that the stud 26 to be inserted into the one mounting hole 24 is arranged concentrically with the mounting hole 24 on the inner side in the axial direction than the rotating flange 13. In this state, when the stud 26 and the wheel bearing unit 5a to which the stud 26 is to be mounted are viewed from the inside in the axial direction, the head 31 of the stud 26 and the outer ring 6 do not overlap each other. I have to.

In the case of manufacturing the wheel bearing unit of the present embodiment, each part of each component of the wheel bearing unit 5a, including the outer ring 6, is connected to the outer surface of the rotating flange 13 (the left side surface in FIG. 1). ) Except for the shape and dimensions. The outer side surface of the rotating side flange 13 is processed into a rough shape and dimensions. Next, each constituent member of the wheel bearing unit 5a except for the stud 26 is shown in FIGS.
Assemble to the state shown in 3. That is, a state in which a plurality of balls 17, 17 are provided between the outer raceways 11a, 11b provided on the inner circumferential surface of the outer race 6 and the inner raceways 14a, 14b provided on the outer circumferential surfaces of the hub 8a and the inner race 16. Then, the outer ring 6, the hub 8a, the inner ring 16, and the plurality of balls 17, 17 are assembled. A pair of seal rings 1 is provided between inner peripheral surfaces of both ends of the outer race 6 and outer peripheral surfaces of ends of the hub 8a and the inner race 16.
9a and 19b are provided.

Then, in this state, the wheel bearing unit 5a to be turned on the outer side surface of the rotary side flange 13 is installed in a turning device (not shown). In this case, for example, a cylindrical surface portion 32 provided at a portion on the outer peripheral surface of the intermediate portion of the outer ring 6 which is deviated inward in the axial direction from the inner surface of the fixed side flange 12 is attached to the tip of the chuck constituting the turning apparatus. Grab by the part. Then, the tip of the spindle provided in the turning device is inserted into the inside of the spline hole 20 provided in the center of the hub 8a from the outer end side of the hub 8a, and provided on the outer peripheral surface of the tip of the spindle. The male spline portion and the spline hole 20 are spline-engaged. Then, by rotating the spindle, the precision machining tool (not shown) is abutted against the outer surface of the rotating flange 13 in a state where the hub 8a is rotated about its central axis, and the outer surface is turned. Processing is performed to finish this outer surface into a predetermined shape and dimensions.

When the turning of the outer surface of the rotating flange 13 is completed, the wheel bearing unit 5
a for removing each of the studs 26 from the turning apparatus,
Attached to an automatic assembly device (not shown). At this time, the outer ring 6 and the hub 8a are illustrated in a state where the phase of one of the plurality of mounting holes 24 provided in the rotating side flange 13 and the notch 30 are matched. Not supported by jigs.

One stud 2 is provided axially inward of the rotary side flange 13 and concentric with the mounting hole 24.
6, the pressing member (not shown) is pressed against the end face of the head 31 of the stud 26, and the stud 26
To the mounting hole 24. Then, while aligning the notch 30 provided on the outer peripheral surface of the outer ring 6 with a part of the stud 26, the male screw portion 33 provided in the first half of the stud 26 is inserted into the mounting hole 24,
Subsequently, a serration portion 34 provided at a portion near the base end of the stud 26 is pressed into the mounting hole 24. Further, one side of the head 31 of the stud 26 (the left side in FIG. 1).
Against the inner side surface of the rotation side flange 13. Therefore, the stud 26 is inserted into the mounting hole 24 in the axial direction of the mounting hole 24 from the axially inner end side of the mounting hole 24.

The operation of press-fitting one stud 26 into one mounting hole 24 in this manner is performed similarly for the remaining studs and mounting holes 24. That is, by rotating the hub 8 a by a predetermined angle with respect to the outer ring 6, the mounting holes 24 into which the studs 26 are to be inserted, and the notches 30 provided on the outer peripheral surfaces of the fixed flange 12 and the cylindrical surface portion 32. The studs 26 are pressed into the mounting holes 24 in a state where the phases are matched. When the operation of press-fitting all the studs 26 into all the mounting holes 24 is completed, the wheel bearing unit 5a is removed from the automatic assembling apparatus.

In the case of the method of manufacturing the wheel bearing unit of the present invention configured as described above and the wheel bearing unit obtained by this manufacturing method, after assembling the constituent members of the wheel bearing unit 5a, the hub 8a is assembled. Rotation-side flange 1 provided on the outer peripheral surface for connecting and fixing wheel 1 and rotor 2
The outer surface of No. 3 is subjected to turning to finish it to a predetermined shape and dimensions. For this reason, regardless of dimensional errors and assembly errors that are inevitable in manufacturing the components, the perpendicularity of the side surface of the rotary flange 13 with respect to the rotation center of the hub 8a is increased, and Fixed rotor 2
Swing can be suppressed.

In addition, in the case of the present invention, after turning is performed on the side surface of the rotary side flange 13, the stud 26 is fixedly connected to the rotary side flange 13. Work can be done easily.
When the stud 26 is fixedly connected to the rotating side flange 13, a part of the stud 26 to be inserted into the mounting hole 24 is entirely removed from the axial inner end of the mounting hole 24. Inside this mounting hole 24, this mounting hole 24
Insert along the axial direction of. Therefore, the operation of connecting the stud 26 to the rotating flange 13 can be easily performed, and the cost required for the operation of manufacturing the wheel bearing unit 5a can be reduced. Further, according to the present invention, since the joining operation of the stud 26 to the rotating side flange 13 can be automated, the cost required for the production operation of the wheel bearing unit 5a can be further reduced. Moreover, in the case of the present invention,
A notch 30 is formed in a part of the outer peripheral surface of the outer race 6, and the inside of the notch 30 is aligned with a part of the stud 26 when each of the studs 26 is inserted into each of the mounting holes 24. . For this reason, the size of the wheel bearing unit 5a does not become particularly large, and the radial thickness of the outer ring 6 at a portion separated from the notch 30 can be sufficiently ensured.

Unlike the case of the present invention, no matter how the hub is rotated with respect to the outer ring, when the wheel bearing unit is viewed from the inside in the axial direction, the mounting hole formed in the rotation side flange. When the and the outer ring overlap, the stud cannot be inserted into the mounting hole in the axial direction of the mounting hole. In such a case, when inserting the stud into the mounting hole, insert a part of the stud near the tip into the mounting hole to a certain extent with the center axes of the studs disagreeing. Therefore, it is necessary to press-fit the serration provided on the stud into the mounting hole after the center axes of the stud and the mounting hole are made to coincide with each other while preventing interference between the stud and the outer ring. Such a press-fitting operation is not only troublesome but also difficult to automate by an automatic assembling apparatus. In the case of the present invention, the stud 26 is provided in the mounting hole 24 provided in the rotating flange 13.
Can be inserted in the axial direction of the mounting hole 24 from the beginning,
Such inconvenience does not occur.

Furthermore, in the case of the present embodiment, in order to prevent interference between the outer peripheral surface of the outer race 6 and the stud 26, the outer peripheral surface of the fixed side flange 12 of the outer race 6 and the outer peripheral surface of the cylindrical surface portion 32 are arranged in the circumferential direction. In the portion, a notch 30 having an arc-shaped cross section is formed at a position which is one end in the front-rear direction of the vehicle when assembled to the vehicle. For this reason, the radial thickness of the portion where the notch 30 is present on the outer peripheral surface of the outer ring 6 in a part of the outer ring 6 in the circumferential direction becomes relatively small. The thickness in the radial direction at two positions on the opposite side in the radial direction of the outer race as a part can be sufficiently large. Therefore, in the case of the present example, the radial thickness of the outer race 6 in the vertical direction, which greatly affects the secondary moment of area related to the bending moment acting on the outer race 6 during turning of the vehicle, can be sufficiently increased. Despite forming the notch 30 in a part of the outer peripheral surface of the outer race 6, the durability of the wheel bearing unit 5a can be sufficiently ensured.

The notch 30, unlike the case of this embodiment, is a part of the outer peripheral surface of the fixed side flange 12 and the cylindrical surface portion 32 in the circumferential direction, and is different from the front-back direction of the vehicle when assembled to the vehicle. It can also be formed at a position to be an end (the left end in FIG. 2). When the outer ring 6 is formed by forging, if a shape of a die used for forging is extremely asymmetric with respect to the center axis of the die, a large bending moment acts on the die, and The life of the mold may be shortened. In the case of this example, each of the fixed-side flange 12 and the cylindrical surface portion 32 of the outer ring 6 has the circumferential direction 1.
Since the notch 30 is formed only at the position, when the outer ring 6 is formed by forging, the shape of the die used for forging is asymmetric with respect to the center axis of the die. Therefore, when the present invention is carried out and the outer race 6 is formed by forging, the notch 3 is preferably used in order to extend the life of the die used for the forging.
0 are formed at two positions on the opposite side in the radial direction of the outer ring 6, respectively, so that the shape of the mold approaches a shape symmetric with respect to the central axis. In this way, the bending moment acting on the die during forging of the outer ring 6 can be sufficiently reduced, so that the life of the die is prolonged and the production cost during mass production of the wheel bearing unit 5a is increased. Can be reduced.

Next, FIGS. 4 to 7 show a second example of the embodiment of the present invention. In the case of this example, a pair of inner rings 16, 16 are externally fitted and fixed to the outer peripheral surface of the intermediate portion of the hub 8 b, and the inner ring raceway 14 is fixed to the outer peripheral surface of each of the inner rings 16, 16.
a and 14b are formed. Also, a pair of seal rings 19a, 19b for sealing the internal space 27 provided with the plurality of balls 17, 17 from the outside are provided at the outer peripheral surfaces at the end portions of the inner rings 16, 16 and at the inner peripheral surfaces at both ends of the outer ring 6. And is provided between them.

In particular, in the case of the present embodiment, a part of the head 31 of each stud 26 in the circumferential direction for insertion into the plurality of mounting holes 24, 24 provided in the rotating flange 13 of the hub 8b, A planar second notch 35 is formed. or,
A notch 30 having an arc-shaped cross section is formed only on the outer peripheral surface of the fixed side flange 12 provided on the outer ring 6. In the case of the present example, unlike the case of the above-described first example, a notch is not formed on the outer peripheral surface of the outer ring 6 on the outer peripheral surface of the cylindrical surface portion 32 provided near the inner end in the axial direction. . Therefore, in the case of this example, the depth d of the notch 30 formed on the outer peripheral surface of the fixed side flange 12 in the radial direction of the outer ring 6 is d.
₃₀ (FIG. 5) can be made smaller than in the case of the first example described above.

The positions of the cutouts 30 provided in the fixed side flange 12 and the mounting holes 24 are regulated in a predetermined relationship described below. First, in a state where each component of the wheel bearing unit 5a is assembled, a plurality of mounting holes 24, 2 and 2 provided in the rotation side flange 13 of the outer ring 6 are provided.
4, it is assumed that one mounting hole 24 and the notch 30 have the same phase. Then, it is assumed that the stud 26 to be inserted into the one mounting hole 24 is disposed concentrically with the mounting hole 24 inside the rotation side flange 13 in the axial direction. In this case, the second notch 35 formed in the head 31 of the stud 26 is used.
Is directed toward the notch 30 formed in the fixed side flange 12. Then, in this state, when the stud 26 and the wheel bearing unit 5a to which the stud 26 is to be mounted are viewed from the inside in the axial direction, the head 31 of the stud 26 and the outer ring 6 do not overlap. I have.

When the wheel bearing unit of this embodiment having the above-described structure is manufactured, the hub 8b is rotated while the respective components of the wheel bearing unit 5a are assembled, and the rotating flange is rotated. Turning the outer surface of 13 to a predetermined shape and dimensions. Next, the notch 30 and 1 formed on the outer peripheral surface of the outer ring 6 are provided to the automatic assembling apparatus (not shown) by mounting the wheel bearing unit 5a.
Attached in a state where the phases of the mounting holes 24 coincide with each other, and inward in the axial direction with respect to the rotating side flange 13,
One stud 26 is arranged concentrically with the mounting hole 24. In this case, the second notch 35 formed on the head 31 of the stud 26 is directed toward the notch 30 formed on the outer peripheral surface of the outer ring 6. Then, by applying a load to the stud 26 by a pressing device (not shown), the stud 26 is positioned inside the mounting hole 24 while aligning one side of the second notch 35 with the inside of the notch 30. Is press-fitted along the axial direction of the mounting hole 24. The operation of press-fitting one stud 26 into one mounting hole 24 in this manner is performed in the same manner for the remaining studs 26 and mounting holes 24.

In the case of this embodiment as well, as in the case of the above-described first embodiment, the working of the outer surface of the rotary flange 13 can be easily performed, and the stud 26 for the rotary flange 13 can be formed. The joining operation can be performed easily. or,
In the case of this example, since the second notch 35 is formed in a part of the head 31 of each stud 26 in the circumferential direction, the cylindrical surface portion 32 provided near the axial inner end of the outer ring 6 is provided. Without forming a notch on the fixed side flange 12
The structure is such that the depth d ₃₀ of the notch 30 is relatively small, and the mounting hole 24 formed in the rotating side flange 13 is
The work of press-fitting each of the studs 26 into 24 can be easily performed. Other configurations and operations are the same as those in the above-described first example, and thus redundant description will be omitted.

When the stud 26 is inserted into the mounting hole 24 provided in the rotary side flange 13 separately from the case of the present embodiment, a second cut is made in a part of the head 31 of the stud 26 in the circumferential direction. As long as interference between the stud 26 and the outer ring 6 can be prevented only by forming the notch 35, the notch 30 (FIGS. 4 and 5) need not be formed on the outer peripheral surface of the outer ring 6.

In each of the above-described examples, the case where the outer surface of the rotating flange 13 is turned to finish the outer surface to a predetermined shape and size has been described.
The present invention is not limited to such a case. The present invention can be carried out even when the outer side surface of the rotating side flange 13 is finished to a predetermined shape and dimensions by grinding or the like using a grindstone.

[0039]

Since the wheel bearing unit and the method of manufacturing the same according to the present invention are constructed and operated as described above, a structure capable of sufficiently suppressing unpleasant noise and vibration generated during braking can be obtained at low cost. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a first example of an embodiment of the present invention in a state immediately before one stud is inserted into one of a plurality of mounting holes provided in a rotating flange. AO of 2
-B sectional drawing.

FIG. 2 is a view from the right side of FIG. 1, showing a state before a stud is inserted into a mounting hole provided in a rotation side flange.

FIG. 3 is an enlarged view of a portion C in FIG. 2;

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

FIG. 5 is a view similar to FIG. 3, showing a second example.

FIG. 6 is a view showing a stud used for a wheel bearing unit of a second example.

FIG. 7 is a view seen from the right side of FIG. 6;

FIG. 8 is a sectional view showing an example of an assembled state of the wheel bearing unit to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wheel 2 Rotor 3 Knuckle 4 Support hole 5, 5a Wheel bearing unit 6 Outer ring 7 Bolt 8, 8a, 8b Hub 9 Stud 10 Nut 11a, 11b Outer ring track 12 Fixed side flange 13 Rotation side flange 14a, 14b Inner ring track 15 Small diameter Step 16 Inner ring 17 Ball 18 Cage 19a, 19b Seal ring 20 Spline hole 21 Constant velocity joint 22 Spline shaft 23, 23a Rotating member 24 Mounting hole 25 Caulking section 26 Stud 27 Internal space 28 Core metal 29 Encoder 30 Notch 31 Head Part 32 Cylindrical surface part 33 Male thread part 34 Male serration part 35 Second notch

Continued on front page F-term (reference) 3J017 HA02 HA04 3J101 AA02 AA32 AA43 AA54 AA62 DA11 FA01 GA03

Claims (2)

[Claims] 1. An outer ring which has a fixed side flange for fixing to a vehicle body on an outer peripheral surface, an outer ring raceway on an inner peripheral surface, and which does not rotate during use, and an inner raceway on an outer peripheral surface. A rotating member that rotates, a plurality of rolling elements provided between the inner raceway and the outer raceway, and a braking rotation provided on an outer peripheral surface of an outer end portion of the rotating member in use in use. In a wheel bearing unit having a rotating flange for coupling and fixing a body and a wheel, a mounting hole formed in a part of the rotating flange and the rotating flange inserted into the mounting hole are provided. Studs fixed to the
A notch formed in a part of an outer peripheral surface of at least one of the outer ring and the stud, wherein the stud is formed by assembling the outer ring, a rotating member, and a plurality of rolling elements, and then rotating the rotating side flange. After the side surface is machined into a predetermined shape and dimensions, the notch is aligned with the outer peripheral surface of the stud or the outer ring, and inserted into the mounting hole from the axially inner end side of the mounting hole, and the rotation is performed. A wheel bearing unit which is fixedly connected to a side flange. 2. The method for manufacturing a bearing unit for a wheel according to claim 1, wherein after assembling the outer ring, a rotating member, and a plurality of rolling elements, the braking is performed while rotating the rotating member with respect to the outer ring. After machining the side surface of the rotating side flange for connecting and fixing the rotating body and the wheels to a predetermined shape and dimensions, aligning the notch with the outer peripheral surface of the stud or the outer ring, and attaching the stud to the shaft of the mounting hole. A method of manufacturing a bearing unit for a wheel, wherein the stud is inserted into the mounting hole from the inner side in the direction to couple and fix the stud to the rotating flange.