JP2002347406A - Bearing unit for wheel and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide structure capable of preventing judder during the application of braking at a low cost by restraining the vibration of the rotor fixed to a hub 8a. SOLUTION: An assembled bearing unit 5a for wheels, the outside face of a rotation side flange 13a of which is to be turned, is installed in a turning unit 39. An engagement section 46 which is arranged at the tip of the rotation axis 45 of the turning unit 39 is engaged directly with an engaging recessed section 43, which is formed at the center section of the axial outer end face of the hub 8a, and the cross section of a part of which is hexagonal. Turning is applied to the outer side face of the rotation side flange 13a while rotating the hub 8a in relation to an outer ring 6 by the rotation axis 45.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel for use as a driven wheel of an automobile (a front wheel of an FR car and an RR car, a rear wheel of an FF car) and a wheel for supporting a rotating body for braking such as a rotor or a drum. The present invention relates to an improvement in a bearing unit and a method for 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 by a knuckle 3 constituting a suspension device, for example, by a structure as shown in FIG. 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 each figure except FIG. Conversely, the right side of each drawing except for FIG. 3, which is the center side 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. 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. Then, the inner ring raceway 14b formed on the outer peripheral surface of the inner ring 16 is connected to the inner outer ring raceway 1 of the double row outer ring raceways 11a and 11b.
1b.

[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 supporting drive wheels (rear wheels of FR and RR vehicles, front wheels of FF vehicles, and all wheels of 4WD vehicles). , A spline hole 20 is formed. The spline shaft 22 of the constant velocity joint 21 is inserted into the spline hole 20.

When using the above-described rolling bearing unit 5 for a wheel, as shown in FIG. 6, the outer ring 6 is fixed to the knuckle 3 and a wheel (not shown) is combined with a rotating side flange 13 of the hub 8 and a tire (not shown). 1 and the rotor 2 are 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.
In the present specification, the friction surface for braking means both axial sides of the rotor when the rotating body for braking is a rotor, and the drum when the rotating body for braking is a drum. Of the inner circumference.

[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 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 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 apparatus, the hub is rotated by a spindle inserted inside the hub, and the rotation provided on the outer peripheral surface of the hub is rotated. A grinding tool is abutted against one side surface of the side flange, and this one side surface is finished to a predetermined shape and dimensions. In the case where the wheel bearing unit is manufactured by such a method, the right angle of one side of the rotating flange with respect to the center of rotation of the hub is improved irrespective of dimensional errors and assembly errors inevitable in manufacturing each component. As a result, it is possible to suppress the vibration of the braking friction surface of the rotary brake such as the rotor fixed to one side surface.

[0009]

In the method of manufacturing a bearing unit for a wheel described in US Pat. No. 6,071,180 described above, a bearing unit for a wheel for supporting a drive wheel is manufactured. Only the thing is considered, the method of manufacturing the bearing unit for the wheel for supporting the driven wheel,
Not specifically considered. On the other hand, in the case of a wheel bearing unit for supporting a driven wheel, since a through hole is not required at the center of the hub, generally, for securing strength, etc.,
This hub is solid. For this reason, in the case of a general wheel bearing unit used to support a driven wheel, a jig such as a rotatable spindle or the like is used to rotate the hub with respect to the outer ring when machining one side of the rotating flange. It is difficult to couple a part of the hub to the hub so that the rotational force can be transmitted. Therefore, it is difficult to manufacture a wheel bearing unit for supporting a driven wheel by the method described in the above-mentioned US patent specification.

In the method of manufacturing a bearing unit for a wheel described in the above-mentioned US patent specification, a connecting member called a flexible adapter element provided on an outer peripheral surface of a tip portion of the spindle is provided inside a hub. In the fitted state, the hub is rotated by the spindle.
Although the above specification does not specifically describe a specific material constituting the connection member, from the usage state of the connection member described in the specification, the connection member is made of rubber or the like. It is considered to be made of elastic material. If the connecting member is made of an elastic material, the connecting member is fitted inside the hub while being elastically deformed.
Since it is necessary to repeat the process each time one wheel bearing unit is manufactured, the connecting member may fatigue relatively early and may not be able to secure required performance. And
In this case, during mass production of the wheel bearing unit, the frequency of replacing the spindle including the connection member increases, and it becomes difficult to manufacture many wheel bearing units using one spindle. This causes an increase in the manufacturing cost of the wheel bearing unit. The wheel bearing unit and the method of manufacturing the same according to the present invention have been made in view of such circumstances.

[0011]

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 wheels provided on an outer peripheral surface of an outer end portion of the rotating member and used as braking rotary bodies and driven wheels on side surfaces thereof in use. And a rotation side flange for coupling and fixing.

[0012] In particular, in the wheel bearing unit according to the first aspect, an engaging recess having at least a part of a non-circular cross section is formed at the center of one end surface in the axial direction of the rotating member. I have. And the side surface of the rotating side flange for coupling and fixing the rotating body for braking and the wheel, or the frictional surface for braking of the rotating body for braking fixed to this side surface, the outer ring, the rotating member and the plurality of rolling elements Is assembled into a predetermined shape and dimensions while rotating the rotating member with respect to the outer ring by a rotating shaft having a tip portion engaged with the engaging recess.

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, the rotating member, and the plurality of rolling elements are assembled. After that, the leading end of the rotating shaft is engaged with an engaging recess formed at the center of one end surface in the axial direction of the rotating member. The side surface of the rotating flange for connecting and fixing the rotating body and the wheel, or the braking friction surface of the braking rotating body fixed to this side surface is processed into a predetermined shape and dimensions.

[0014]

According to the wheel bearing unit and the method of manufacturing the same according to the present invention, the rotation of the rotating member with respect to the center of rotation of the rotating member can be performed irrespective of dimensional errors and assembly errors which are inevitable in manufacturing each component. By increasing the squareness of the side surface of the side flange or the squareness or parallelism of the side surface of the friction surface for braking, it is possible to suppress the deflection of the friction surface for braking. In addition, in the case of the present invention, by utilizing the engaging recess provided in the center of the rotating member, even if there is no through hole in the center of the rotating member, the side surface of the rotating flange or the brake Processing of the braking friction surface of the rotating body can be easily performed. Further, the tip of the rotating shaft made of a relatively hard material such as metal can be directly engaged with the engaging recess.
For this reason, the durability of the tip portion of the rotating shaft can be ensured, and the production cost during mass production of the wheel bearing unit can be reduced.
In addition, since the engaging recess can be formed by inexpensive forging, in this case, the manufacturing cost of the wheel bearing unit can be reduced more sufficiently.

Further, in the present invention, when the braking friction surface of the braking rotator fixed to the side surface of the rotating flange provided on the rotating member is processed into a predetermined shape and size, the rotating flange and the rotating flange may be fixed to each other. The assembly error which is inevitable in manufacturing, which is present in the mounting portion with the braking rotator, does not lead to the deterioration of the perpendicularity or parallelism of the braking friction surface of the braking rotator. Therefore, in such a case, the braking rotary body in which the braking friction surface is processed into a predetermined shape and size in advance is used.
The deflection of the braking friction surface of the braking rotator can be suppressed more than in the case where the rotating body is fixed to the side surface of the rotating flange. Further, in this case, it is not necessary to particularly improve the shape accuracy of the mounting portion between the braking rotator and the rotating flange, and the cost required to suppress the deflection of the braking rotator is sufficiently reduced. Can be suppressed.

[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 example has 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 the 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.

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. A caulking portion 24 is formed at the inner end of the hub 8a to prevent the inner ring 16 from coming out of the small diameter step portion 15. 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 race 16 at the inner end of the hub 8a is plastically deformed radially outward to form the swaged portion 24, and the swaged portion 24 forms the inner race 16 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.

Further, the wheel bearing unit of the present invention is for supporting a wheel used as a driven wheel. For this reason, in the case of this example, unlike the case of the conventional structure shown in FIG. 6 described above, the spline shaft 22 of the constant velocity joint 21 that penetrates the hub 8a in the axial direction is inserted into the center of the hub 8a. No spline hole 20 (FIG. 6) is formed. In the case of the present invention, a portion of the outer peripheral surface of the hub 8a near the outer end 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. Rotating flange 1 for fixing (Fig. 6)
3a is provided. At a plurality of positions in the circumferential direction of the rotating side flange 13a, mounting holes 25 are formed on the same circumference centered on the rotation center of the hub 8a, and a plurality of studs are formed inside each of the mounting holes 25. 9 (see Fig. 6)
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 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.

Particularly, in the case of the present invention, an engaging recess 43 having a hexagonal cross section is formed by forging at the center of the axially outer end surface of the hub 8a. In addition, a conical hole 44 is formed at the bottom of the engagement recess 43. A hexagonal column-shaped engaging portion 4 provided at the tip of a rotating shaft 45 rotatably supported by a part of the turning device 39.
6 is freely engageable with the engagement recess 43.

In the case of the present embodiment, a single cylindrical surface portion 30 is provided over the entire circumference at the portion where the outer diameter is the largest on the outer peripheral surface of the rotating flange 13a provided on the hub 8a. . Then, the outer diameter D ₃₀ of the cylindrical surface portion ₃₀ (FIG. 2)
The diameter of the circumscribed circle of the fixed side flange 12 provided on the outer peripheral surface of the outer ring 6 is larger than the diameter D ₁₂ (FIG. 2) (D ₃₀ > D).
₁₂ ). Turning is performed on the outer surface of the rotating side flange 13a in a predetermined state, and the outer surface is finished to a predetermined shape and dimensions.

That is, when turning is performed on the outer surface of the rotating side flange 13a, first, the wheel bearing unit 5a
Each part of each constituent member is machined into a predetermined shape and size except for the outer side surface of the rotating side flange 13a. 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 5a are assembled in the state shown in FIGS. That is, the outer raceway 11 provided on the inner peripheral surface of the outer race 6
a, 11b and a plurality of balls 17, 1 between the inner ring raceways 14a, 14b provided on the outer peripheral surface of the hub 8a and the inner ring 16;
The outer ring 6, the hub 8a, the inner ring 16, and the plurality of balls 17, 17 are assembled with the 7 provided. A pair of seal rings 19a and 19b are provided between the inner peripheral surfaces of both ends of the outer race 6 and the outer peripheral surfaces of the ends of the hub 8a and the inner race 16. Also, a plurality of studs 9 are provided on the rotation side flange 13a.
The base end of FIG. 6 is fixed.

In this state, the closing member 31 is externally fitted and fixed to the small-diameter step portion 38 provided on the outer peripheral surface of the inner end portion of the outer ring 6. The closing member 31 is formed in a cylindrical shape with a bottom by injection molding synthetic resin. That is, the closing member 31 includes a cylindrical portion 32 and a bottom plate portion 33 for closing the inner end (the right end in FIGS. 1 and 2) of the cylindrical portion 32.
In the bottom plate portion 33, a knob portion 34 protrudes from the center of the side surface on the side opposite to the cylindrical portion 32. The cylindrical portion 32 is formed by connecting a small-diameter cylindrical portion 35 and a large-diameter cylindrical portion 36 which are concentric with each other by a step portion 37. The closing member 31 is externally fitted and fixed to the small-diameter stepped portion 38 when the outer surface of the rotary side flange 13a is turned. Also, a step 37 provided at an intermediate portion of the cylindrical portion 32
Is abutted against the inner end surface of the outer ring 6.

Then, in this state, the rotating flange 13
bearing unit 5 for a wheel to be turned on the outer surface of a
a is installed in the turning device 39. In this case, of the outer peripheral surface of the outer ring 6, the cylindrical surface portion 49 provided axially inside the inner side surface of the fixed side flange 12 and axially outside the outer end of the small-diameter stepped portion 38 is subjected to the turning. Processing equipment 3
9 is gripped by the tip of the chuck 40. In addition, the distal end surface (the left end surface in FIGS. 1 and 2) of the chuck 40 abuts on the inner side 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 40 is formed of a sleeve 41 made of a relatively soft material such as synthetic resin, aluminum, or copper. Then, with the cylindrical surface portion 49 provided on the outer peripheral surface of the outer ring 6 held by the chuck 40, the outer peripheral surface of the cylindrical surface portion 49 is brought into contact with only the inner peripheral surface of the sleeve 41.

Further, in the case of the present embodiment, the base end of a cylindrical cover 42 made of a metal plate such as a steel plate or a synthetic resin, and whose inner and outer peripheral surfaces are merely cylindrical surfaces, is attached to the turning device 39. The part is fixed. Also, the inner diameter d of the cover 42
₄₂ (FIG. 2), it is slightly greater than the outer diameter D ₃₀ of the cylindrical surface portion 30 provided on the rotating side flange 13a (d ₄₂
> D ₃₀ ). When the wheel bearing unit 5a is installed in the turning device 39, the wheel bearing unit 5a in which the closing member 31 is fixed to the inner end of the outer ring 6 is used.
Is inserted into the inside of the cover 42 in a state where the closing member 31 is in front. And, the rotating side flange 13
The cover 42 covers the periphery of a portion extending from the outer diameter side of the axially intermediate portion of the cylindrical surface portion 30 provided at a to the outer diameter side of the inner end of the closing member 31. The portion of the rotation side flange 13a near the axial outer end and the portion of the hub 8a near the axial outer end are not inserted into the inside of the cover 42 but protrude from the outer end of the cover 42.

In the case of this example, Japanese Patent Application No. 2000-45
No. 479, the studs 9 are attached to the rotating flange 13a.
In order to easily perform the turning process on the outer surface of the rotating side flange 13a in a state where is fixed. That is, in the case of the present example, an annular concave portion 47 is formed over the entire circumference at the radially intermediate portion of the outer side surface of the rotating side flange 13a. One end (left end in FIGS. 1 and 2) of the plurality of mounting holes 25 for fixing the base end of each stud 9 is opened in the recess 47. This recess 4
The width W _{47 in} the radial direction of 7 is larger than the inner diameter d ₂₅ (FIG. 2) of each of the mounting holes 25 (W ₄₇ >).
d ₂₅ ). With the base end of each stud 9 fixed to the rotating flange 13a, the portion of each stud 9 protruding from the outer surface of the rotating flange 13a is indicated by a chain line α in FIG. Cylindrical virtual space (the cross-section is a white portion in FIG. 3) existing between the virtual cylindrical surface including the outer peripheral edge of the concave portion 47 and the virtual cylindrical surface also including the inner peripheral edge, also indicated by a chain line β. Exists within.

Then, an engaging portion 46 provided at the distal end of the rotating shaft 45 of the turning device 39 is engaged with an engaging concave portion 43 provided at the center of the axially outer end surface of the hub 8a.
Next, the hub 8a is rotated about its central axis by rotating the rotary shaft 45. In this state, a portion sandwiching the concave portion 47 from both sides in the radial direction on the outer surface of the rotating flange 13a (oblique lattice portion in FIG. 3).
, Butted two precision machining tools 48a, 48b,
Turning is performed on each of these parts to finish the outer surface of the rotating flange 13a into a predetermined shape and dimensions.

As described above, in the case of the manufacturing method of 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 5a, the hub 8a is assembled. 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, regardless of dimensional errors and assembly errors that are inevitable in manufacturing the components, the perpendicularity of the side surface of the rotation side flange 13a with respect to the rotation center of the hub 8a is increased, and the rotation side flange 13a It is possible to suppress run-out on both sides, which are the friction surfaces for braking, of the fixed rotor 2.

Further, in the case of the present invention, the hub 8a
At the center of the axially outer end face of the turning section 39, an engaging recess 43 having a hexagonal cross-sectional shape is formed, and the rotating shaft 45 of the turning device 39 in which the leading end is engaged with the engaging recess 43, Turning the outer surface of the rotating flange 13a while turning the hub 8a with respect to the outer ring 6.
For this reason, even if there is no through hole in the center of the hub 8a, the working of the outer side surface of the rotating flange 13a can be easily performed. Further, the engaging recess 46 can be directly engaged with the engaging portion 46 of the rotary shaft 45 made of a relatively hard material such as metal. For this reason, the durability of the engagement portion 46 can be sufficiently ensured, the frequency of replacement of the jig can be reduced, and the production cost during mass production of the wheel bearing unit 5a can be reduced. Further, in the case of this example, the engagement recess 43 is used.
Is formed by inexpensive forging, so that the manufacturing cost of the wheel bearing unit 5a can be reduced more sufficiently.

Further, in the case of this embodiment, when machining the outer surface of the rotating flange 13a, the inner ring 6 is formed from the outer diameter side of the cylindrical surface portion 30 provided on the outer peripheral surface of the rotating flange 13a. A portion around the outer diameter side of the end is covered with a cylindrical cover 42. Further, in the outer peripheral surface of the rotary side flange 13a, the portion where the outer diameter is greatest, provided with a single cylindrical surface portion 30, the outer diameter D ₃₀ of the cylindrical surface portion 30, of the circumscribed circle of the fixed side flange 12 It is made larger than the diameter _{D 12 (D 30> D 12} ). Therefore, even if the periphery of the predetermined portion is covered with the cylindrical cover 42,
Interference between the cover 42 and the fixed side flange 12 can be prevented. In addition, the gap between the inner peripheral surface of the cover 42 and the outer peripheral surface of the cylindrical surface portion 30 of the rotating flange 13a can be made sufficiently small. Therefore, at the time of turning on the outer side surface of the rotating side flange 13a, foreign substances such as cutting chips generated by the turning enter the internal space 27 provided with the plurality of balls 17, 17 or each seal ring 19a. ,
19b can be sufficiently prevented from being damaged by the foreign matter. Therefore, the durability of the wheel bearing unit 5a can be sufficiently ensured, and foreign matter such as cutting powder of a magnetic material can be prevented from adhering to the encoder 29, which is a permanent magnet, and the wheel fixed to the hub 8a can be prevented. The accuracy of rotation speed detection can be improved. In addition, a dynamic pressure groove is formed in the cylindrical surface portion 30, and between the cylindrical surface portion 30 and the inner peripheral surface of the cover 42 with the rotation of the rotation-side flange 13 a, goes from inside to outside of the cover 42. If the flow is caused, the entry of foreign matter into the internal space 27 can be more reliably prevented.

Further, in the case of the present embodiment, a closing member 31 is externally fitted and fixed to the inner end of the outer ring 6 at the time of turning the outer surface of the rotary side flange 13a. Therefore, in combination with covering a part of the periphery of the wheel bearing unit 5a with the cylindrical cover 31, foreign matter enters the internal space 27 from the inner ends of the outer ring 6 and the hub 8a. Can be prevented more reliably. When the turning is completed, the wheel bearing unit 5a is removed from the turning device 39, and the closing member 31 is further removed from the inner end of the outer ring 6. In this manner, the work of removing the closing member 31 can be easily performed by an operator pulling the knob 34 provided on the closing member 31. Moreover, since the work of attaching and detaching the closing member 31 to and from the outer ring 6 can be performed at a place sufficiently distant from the turning device 39 and where there is no swarf, entry of foreign matter into the internal space 27 and It is possible to sufficiently prevent the cutting powder of the magnetic material from adhering to the encoder 29 which is a permanent magnet.

Unlike the case of the present embodiment, instead of omitting the closing member 31, the base end of a cylindrical second cover (not shown) is fixed to a part of the turning device 39. When turning, the tip of the second cover can be fitted over the inner end of the outer race 6. Even in this case, it is possible to sufficiently prevent foreign matter from entering the internal space 27 from the inner ends of the outer ring 6 and the hub 8a as in the case of the present example using the closing member 31.
When the second cover is externally fitted to the inner end of the outer ring 6 in this manner, the second cover is attached to the outer cover 6 so that the outer cover can be easily fitted. It is preferable that the outer ring 6 is fitted to the inner end of the outer ring 6 with a clearance fit. Even when the second cover is fitted to the outer ring by a clearance fit in this way, the base end of the second cover is fixed to a part of the turning device 39. The second cover does not come off the inner end of the outer ring 6.

Further, in the case of this embodiment, the cylindrical surface portion 49 provided on the outer peripheral surface of the outer ring 6 is gripped by the chuck 40 of the turning device 39, and the outer peripheral surface of the cylindrical surface portion 49 is relatively soft. Only the inner peripheral surface of the sleeve 41 made of a material is brought into contact. The relatively hard metal portion of the chuck 40 does not contact the outer peripheral surface of the cylindrical surface portion 49. For this reason, the cylindrical portion 49 can be prevented from being damaged by the metal portion constituting the chuck 40, and the shape accuracy of the cylindrical surface portion 49 can be sufficiently ensured. The cylindrical surface portion 49 is provided with the wheel bearing unit 5.
a, which is fitted inside the support hole 4 (FIG. 6) of the knuckle 3. In the case of this example in which the accuracy of the shape of the cylindrical surface portion 49 can be sufficiently ensured, one of the outer ring 6 is used. The portion can be fitted and fixed inside the support hole 4 without rattling.

In the case of this embodiment, an annular concave portion 47 is formed at the radially intermediate portion of the outer side surface of the rotating side flange 13a, and a plurality of mounting holes 25 for fixing the plurality of studs 9 are formed. One end in the axial direction is opened in the recess 47. For this reason, at the time of turning with each precision machining tool 48a, 48b, these precision machining tools 48a, 48b
And the studs 9 fixed to the mounting holes 25 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. In addition, on the outer side surface of the rotating side flange 13a, it is possible to perform turning on almost all portions sandwiching the concave portion 47 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 recess 47 can be made flat, and the runout of the rotor 2 fixed to the outer surface can be sufficiently suppressed.

Next, FIG. 4 shows a second embodiment of the present invention.
An example is shown. In the case of this example, outside the middle portion of the hub 8a
A pair of inner rings 16, 16 are externally fitted and fixed to the peripheral surface, and
Inner ring raceways 14a, 14
b is formed. In addition, in the case where a plurality of balls 17 are provided,
A pair of seal rings for sealing the space 27 from outside
19a, 19b, the outer peripheral surface of the end portion of each of the inner rings 16, 16
And between the inner peripheral surfaces of both ends of the outer ring 6. Furthermore, the book
In the case of the example, the rotating flange 1 provided on the hub 8a is used.
When turning on the outer surface of 3a, it should be turned.
The wheel bearing unit 5a to the turning device 39
And a part of the wheel bearing unit 5a is
Cover 42a made of a metal plate such as
Covered by. Also, at the tip of the cover 42a,
An inward flange 50 projecting toward the inner diameter side is formed over the entire circumference.
You. Inner diameter d of this inward flange 50₅₀Is the above rotating franc
Outer diameter D of the cylindrical surface portion 30 provided on the outer peripheral surface of the die 13a₃₀Than
Is also slightly larger (d₅₀> D ₃₀).

The inner surface of the inward flange portion 47 (FIG. 4)
The right end surface of the cover 42a and the inner peripheral surface of the distal end of the cover 42a are connected to the base end of a seal ring 51 made of an elastic material such as rubber over the entire circumference. The inner diameter d ₅₁ in the free state of the seal ring 51 is slightly smaller than the outer diameter D ₃₀ of the cylindrical surface portion _{30 (d 51 <D 30)} . Therefore, the wheel bearing unit 5a to be subjected to the turning process is connected to the turning device 3
9, the distal end edge of the seal ring 51 elastically contacts the outer peripheral surface of the cylindrical surface portion 30 over the entire circumference.

In the case of this embodiment, turning is performed on the outer surface of the rotating flange 13a without fixing the stud 9 (see FIG. 6) to the rotating flange 13a. In addition, during the turning process, the rotating side flange 1
A suitable lid member (not shown) is attached to the inner end opening of the mounting hole 25 provided to fix the base end of the stud 9 at a plurality of positions in the circumferential direction of 3a, and the mounting hole 25 is closed. Then, the entire outer surface is turned by one precision cutting tool (not shown) to finish the outer surface into a predetermined shape and dimensions. In the case of this example, as described below, since the sealing performance between the inside and outside of the cover 42a can be sufficiently ensured by the seal ring 50, the inner end of the outer ring 6 is closed when the turning is performed. The member 31 (see FIGS. 1 and 2) is not externally fixed.

In the case of this example, the tip edge of the seal ring 50 is fixed to the cylindrical surface portion 30 during turning.
The cover 42a is in sliding contact with the outer peripheral surface of the
Between the inner peripheral surface of the distal end portion and the outer peripheral surface of the cylindrical surface portion 30 can be sufficiently sealed. For this reason, it is possible to more reliably prevent foreign substances generated during the turning process from entering the internal space 27 provided with the plurality of balls 17. Further, in the case of this example, the plurality of studs 9 are attached to the rotating side flange 13a.
Since the turning is performed on the outer side surface of the rotary side flange 13a without fixing the studs 9, it is not necessary to consider the prevention of interference between the stud 9 and the precision machining bit during the turning. The stud 9 is press-fitted and fixed in the mounting hole 25 after the turning process. For this reason, turning can be performed on the outer surface of the rotating side flange 13a with one precision machining tool, and an annular concave portion 47 (see FIGS. 1 to 3) is formed at a radially intermediate portion of the outer surface. You don't have to. Other configurations and operations are the same as those in the above-described first example, and thus redundant description will be omitted.

FIG. 5 shows a third embodiment of the present invention.
An example is shown. In the case of this example, while the rotor 2 is fixed to the outer surface of the rotation side flange 13 a provided on the outer peripheral surface of the hub 8 a, while rotating the hub 8 a, the shaft which is the friction surface for braking of the rotor 2 is rotated. Turning is performed on both side surfaces in the direction, and the both side surfaces are finished to predetermined shapes and dimensions.
That is, in the case of this example, after finishing the outer surface of the rotating side flange 13a to a predetermined shape and dimensions, the rotor 2 is coupled to the outer surface by a plurality of studs 9 and nuts 52. I have. Further, both side surfaces of the portion near the outer periphery of the rotor 2 are processed into a desired shape in the process of manufacturing the rotor 2. That is, these two side surfaces are parallel to each other, and are also parallel to both side surfaces of the coupling flange portion 54 provided near the inner periphery in order to couple and fix to the rotating side flange 13a. However, the parallelism between both side surfaces of the coupling flange portion 54 and both side surfaces of the portion near the outer periphery of the rotor 2 may not be very strict.

After assembling the components of the wheel bearing unit 5a and the rotor 2, the turning device 3
9, the both sides of the portion near the outer periphery of the rotor 2 are subjected to turning, and the both sides are finished to predetermined shapes and dimensions. In the case of this example, the turning device 3
9, a base end of a cylindrical cover 42b is provided, and a base end of a seal ring 55 is mounted on the front end surface of the cover 42b over the entire circumference. At the time of the turning, a part of the wheel bearing unit 5a is inserted inside the portion near the front end of the cover 42b, and the front end edge of the seal ring 55 is attached to the inner surface of the portion near the outer periphery of the rotor 2. , And are slid over the entire circumference. Then, the inner ring 1 on the inner peripheral surface of the outer end of the outer ring 6 and the outer ring (left side in FIG. 5)
The part extending from the portion between the outer peripheral surface of the outer end portion 6 and the inner peripheral surface of the inner end portion of the outer race 6 to the inner peripheral surface of the inner race 16 on the inner side (right side in FIG. 5) is referred to as the rotor. 2 and cover 4
2b shields from the outside.

In the case of this example, the turning device 3
9 is provided with an air supply device (not shown), and an air supply port (not shown) provided in the air supply device is opened inside a portion near the base end of the cover 42b. Then, air of (0.5 to 4) × 10 ⁵ Pa at a gauge pressure is sent from the air supply port to the inside of the cover 42b. Therefore, the inner surface of the rotor 2 and the cover 42
b, the air flows out from the space between the front end edge of the seal ring 55 provided to the outside of the rotor 2 and the foreign matter existing outside.
Cover 42 from between the inner surface of the
It can be reliably prevented from entering the inside of b.

Then, the engaging portion 46 provided at the distal end of the rotating shaft 45 of the turning device 39 is engaged with the engaging concave portion 43 formed at the center on the axially outer end surface of the hub 8a. By rotating the rotation shaft 45, the precision machining tools 48b, 48b are abutted against both sides of the rotor 2 while rotating the hub 8a, and the both sides are finished to predetermined shapes and dimensions. I have. When the turning on both sides is completed, the nut 52 is removed from the stud 9. The wheel bearing unit 5a is conveyed from the component manufacturer of the wheel bearing unit to the manufacturer of the finished product of the vehicle with the nut 52 removed from the stud 9. Therefore, when attaching the wheel 1 (see FIG. 6) to one side surface of the rotor 2, the finished product maker can save the trouble of removing the nut 52 from the stud 9.

According to the manufacturing method of the wheel bearing unit of the present embodiment configured as described above and the wheel bearing unit obtained by this manufacturing method, the rotating flange 13a provided on the outer peripheral surface of the hub 8a, the rotor 2 and The mounting error unavoidable in manufacturing, which is present in the mounting portion, does not lead to the deterioration of the perpendicularity of the braking surfaces of the rotor 2 to the rotation center of the rotor 2. Therefore, in the case of this example,
The run-out on both side surfaces of the rotor 2 can be suppressed more sufficiently than in each of the above-described examples. Also, this rotor 2
It is not necessary to particularly improve the shape accuracy of the connecting flange portion 54 and the rotating side flange 13a, and the cost required for suppressing the runout on both side surfaces of the rotor 2 can be sufficiently reduced.

Further, in the case of this embodiment, when turning both sides of the rotor 2, the outer ring 6 is moved from the portion between the inner peripheral surface of the outer end of the outer ring 6 and the outer peripheral surface of the outer end of the outer ring 16 to the outer ring. The portion between the inner peripheral surface of the inner end portion 6 and the outer peripheral surface of the inner end portion of the inner inner ring 16 is shielded from the outside by the rotor 2 and the cover 42b. For this reason, the foreign matter generated during the turning process enters the internal space 27 of the wheel bearing unit 5a provided with the plurality of balls 17, 17 or a seal ring provided to block the internal space 27 from the outside. 19
a and 19b can be sufficiently prevented from being damaged by the foreign matter, and the durability of the wheel bearing unit 5a can be sufficiently ensured.

In the case of this embodiment, the tip edge of the seal ring 55 connected to the tip face of the cover 42b is brought into sliding contact with the inner face of the rotor 2 when the rotor 2 is turned. However, the predetermined edge can be shielded from the outside by sliding the leading edge of the seal ring 55 into contact with a part of the hub 8a, such as the side surface of the rotating flange 13a. In addition, the turning process can be performed while omitting the seal ring 55 and making the distal end surface of the cover 42b approach the inner surface of the rotor 2 or the like via a minute gap. Even in this case, the cover 42
Since air flows out from the inside to the outside through the small gap, the foreign matter can be prevented from entering from outside through the small gap. Other configurations and operations are the same as those of the second example shown in FIG. 4 described above, and therefore, duplicate description will be omitted.

As an application example of this embodiment, a drum constituting a drum brake is fixed to the side surface of the rotary flange 13a, and the inner peripheral surface which is a friction surface for braking of the drum is subjected to turning. This inner peripheral surface can be finished to a predetermined shape and dimensions. In this case, the runout of the inner peripheral surface can be sufficiently suppressed.

In addition to the case of this embodiment, when turning is performed on both side surfaces of the rotor 2, the inside of the step portion 56 provided at a continuous portion between the inner peripheral portion and the outer peripheral portion of the rotor 2 is formed. A relatively large annular space is provided between the peripheral surface and the outer peripheral surface of the rotary side flange 13a, and the distal end of the cylindrical cover, whose base end is fixed to a part of the turning device 39, is formed by the above-described method. It can also be inserted into an annular space. In this case, the outer peripheral surface of the distal end of the cover is made to closely approach the inner peripheral surface of the step portion 56 via a minute gap. Then, in this state, the hub 8a is connected to the rotating shaft 4 of the turning device 39.
Turning is performed on both side surfaces of the rotor 2 while being rotated by 5. Even in this case, it is possible to prevent foreign matter generated during the turning process from entering the internal space 27 of the wheel bearing unit 5a. In this case, the possibility of foreign matter such as cutting chips entering the inside of the cover can be reduced as compared with the structure in which the seal ring 55 is omitted in the present embodiment shown in FIG. The rotor 2 and the hub 8a
There is no need to provide a seal ring for abutting a part of the seal ring.

In each of the above-described embodiments, the cross section of the engaging recess 43 formed at the center of one axial end surface of the hub 8a is hexagonal. ,
Other non-circular shapes such as a square shape can also be used. In this case, the turning device 39 is used in accordance with the shape of the engagement recess.
The shape of the tip of the rotating shaft 45 provided in the above is changed. Furthermore, in each of the above-described examples, a case has been described in which turning is performed on the outer surface of the rotating side flange 13a or both side surfaces of the rotor 2, and the outer surface and the like are finished to predetermined shapes and dimensions.
The present invention is not limited to such a case. The present invention relates to an outer surface of the rotating side flange 13a or the rotor 2
It can be carried out even when the outer surfaces and the like are finished to predetermined shapes and dimensions by grinding or the like using a grindstone on both side surfaces and the like.

[0050]

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 manufactured at low cost.

[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 diagram showing only the hub taken out and viewed from the left side of FIG. 1;

FIG. 4 is a view similar to FIG. 1, but showing a second example of the embodiment of the present invention with a precision machining tool omitted;

FIG. 5 is a sectional view showing a third example of the embodiment of the present invention in a state where turning is performed on both side surfaces of the rotor.

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.

[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 Hub 9 Stud 10 Nut 11a, 11b Outer ring track 12 Fixed flange 13, 13a Rotating 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 Caulking portion 25 Mounting hole 27 Internal space 28 Core metal 29 Encoder 30 Cylindrical surface portion 31 Sealing member 32 Tube part 33 Bottom plate part 34 Knob part 35 Small diameter cylindrical part 36 Large diameter cylindrical part 37 Step part 38 Small diameter step part 39 Turning machine 40 Chuck 41 Sleeve 42, 42a, 42b Cover 43 Engaging concave part 44 Conical hole part 45 Rotating shaft 46 Engagement part 47 recess 8a, 48b precision machining bite 49 cylindrical surface 50 inward flange portion 51 the seal ring 52 nut 54 coupling flange 55 sealing ring 56 step portion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C045 CA03 CA04 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. A wheel-side bearing unit comprising a body and a rotating side flange for connecting and fixing a wheel used as a driven wheel;
At least one part of the rotation member has a non-circular engagement recess formed at the center of one end surface in the axial direction of the rotation member, and a side surface of a rotation side flange for connecting and fixing the brake rotation body and the wheel. Alternatively, the braking friction surface of the braking rotator fixed to the side surface may include a rotating shaft having its outer end, a rotating member, and a plurality of rolling elements assembled with each other, and the leading end thereof engaged with the engaging recess. Thus, the wheel bearing unit is processed into a predetermined shape and dimensions while rotating the rotating member with respect to the outer ring. 2. The method for manufacturing a bearing unit for a wheel according to claim 1, wherein the outer ring, a rotating member, and a plurality of rolling elements are assembled at a central portion of one end surface in the axial direction of the rotating member. The engaging recess, the tip of the rotating shaft is engaged, while rotating the rotating member with respect to the outer ring by the rotating shaft, the side surface of the rotating flange for connecting and fixing the rotating body for braking and the wheel, Or processing the friction surface for braking of the rotating body for braking fixed to this side surface into a predetermined shape and dimensions,
Manufacturing method of wheel bearing unit.