JP2003072308A - Bearing system for driving wheel and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain rattling in the diametrical direction existing between serrations to fit a hub ring and a coupling outer ring and to improve flexural rigidity of the hub ring. SOLUTION: The serrations 35, 36 complementarily fit a made tooth of a shaft part 24 and a female tooth of the hub ring 1 and give pre-load in the diametrical direction of them on a bearing system for a driving wheel furnished with the outer ring 12 forming outer races 5, 6 in double rows on an outer periphery, the hub ring 1 forming one inner race 7 out of the inner races 7, 8 in double rows on an outer periphery, a constant velocity universal coupling 3 having a coupling outer ring 4 forming a shaft part 24 and the other inner race 8 on the outer periphery and rolling elements 9, 10 in double rows stored between the outer races 5, 6 of the outer ring 12 and the inner race 8 of the hub ring 1 and the constant velocity universal coupling 3 and integrally fastening the hub ring 1 and the coupling outer ring 4 in an abutted state by fitting the shaft part 24 on the hub ring 1 through the serrations 35, 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive wheel bearing device for rotatably supporting the drive wheels of an automobile (front wheels of an FF vehicle, rear wheels of an FR vehicle, all wheels of a 4WD vehicle) with respect to a vehicle body. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Various types of bearing devices for driving wheels of automobiles have been proposed according to their applications. For example, in the drive wheel bearing device shown in FIG. 7, the hub wheel 1, the double-row bearing 2 and the constant velocity universal joint 3 are unitized, and the joint outer ring 4 of the constant velocity universal joint 3 is provided on the inner periphery of the hub wheel 1. It has a structure that is press-fitted so that torque can be transmitted.

The bearing 2 is composed of double rows of outer races 5, 6 and inner races 7, 8 and double rows of rolling elements 9, 10 assembled between the outer races 5, 6 and inner races 7, 8. It is a double-row angular contact ball bearing configured. In this bearing device, one of the double-row inner races 7 and 8 is formed on the outer peripheral surface of the hub wheel 1, and the other inner race 8 is formed on the outer peripheral surface of the shoulder portion 11 of the joint outer ring 4. Has been done. Double row outer races 5 and 6 are outer ring 12
Is formed on the inner peripheral surface of the.

The hub wheel 1 has a wheel mounting flange 13 for mounting a wheel, and hub bolts (not shown) for fixing a wheel disk are planted at equal intervals in the circumferential direction of the wheel mounting flange 13. Has been done. Outer ring 12
Has a vehicle body mounting flange 14 for mounting on a vehicle body, and this vehicle body mounting flange 14 is fixed to a knuckle (not shown) extending from a suspension device of the vehicle body by a bolt.
A serration 26 is formed on a part of the inner peripheral surface of the hub wheel 1.

The outer ring 12 is provided at the openings of both ends of the bearing 2.
A pair of seals 15 and 16 for sealing the annular spaces of the hub ring 1 and the joint outer ring 4 are fitted to the inner diameter of the end portion of the outer ring 12 so that the grease filled in the inside leaks and the water or foreign matter enters from the outside. It is designed to prevent

The constant velocity universal joint 3 is provided at one end of a shaft 17 and has a joint outer ring 4 having a track groove 18 formed on the inner peripheral surface thereof and a track groove 19 opposed to the track groove 18 of the joint outer ring 4. The joint inner ring 20 formed on the surface, the ball 21 installed between the track groove 18 of the joint outer ring 4 and the track groove 19 of the joint inner ring 20, and the ball 21 interposed between the joint outer ring 4 and the joint inner ring 20. And a holder 22 for supporting the. The outer joint ring 4 includes a mouth portion 23 accommodating the inner joint ring 20, the ball 21 and the cage 22, and a shaft portion 24 integrally extending axially from the mouth portion 23 and having serrations 25 formed on the outer peripheral surface thereof. Have.

The shaft portion 24 of the joint outer ring 4 is press-fitted into the hub wheel 1, and the two are fitted by the serrations 25 and 26 provided on the outer peripheral surface of the shaft portion 24 and the inner peripheral surface of the hub ring 1, respectively. It is possible to communicate. At this time, hub wheel 1
The preload control of the bearing 2 is performed by abutting the inboard side end surface 27 of the and the end surface 28 of the shoulder portion 11 of the joint outer ring 4. Further, by tightly press-fitting the root portion of the shaft portion 24 of the joint outer ring 4 into the hub wheel 1, centering by the pilot portion 29 ensures the coaxiality between the hub wheel 1 and the joint outer ring 4. Then, the end portion of the shaft portion 24 is plastically deformed to the outer diameter side by, for example, swing caulking, and the caulking portion 30 is engaged with the outboard-side end surface 31 of the hub wheel 1 so that the joint outer ring 4 becomes a hub. It is fixed to the wheel 1, and the hub wheel 1, the bearing 2 and the constant velocity universal joint 3 are unitized.

[0008]

By the way, in the above-mentioned conventional bearing device for a drive wheel, the serration 25 is formed on the outer peripheral surface of the shaft portion 24 of the joint outer ring 4 and the hub wheel 1 is used.
A serration 26 is formed on the inner peripheral surface of the, and the serrations 25 and 26 are fitted to each other so that torque can be transmitted. FIG. 8 is an enlarged cross-sectional view taken along the line AA of FIG. 7, showing the shaft portion 24 of the joint outer ring 4 and both serrations 25 and 26 of the hub wheel 1. As shown in the figure, the serration 25 of the shaft portion 24 is composed of a large number of male teeth 25a, and the serration 26 of the hub wheel 1 is composed of a large number of female teeth 26a.

Both the serrations 2 of the shaft portion 24 and the hub wheel 1
5 and 26, the male tooth 25a of the serration 25 and the female tooth 26a of the serration 26 are fitted by tooth surface alignment. That is, the male teeth 25a and the female teeth 26a are in a state in which the tooth surfaces, which are the side surfaces along the respective axial directions, are butted against each other, and the outer diameter surface of the male teeth 25a and the female teeth 26a.
There is a radial clearance a between the inner surface of the hub wheel and the inner surface of the hub wheel.
Further, in this serration fitting structure, the male teeth 25a
As a means for suppressing the rattling of the male tooth 25a with the female tooth 26a in the circumferential direction, the tooth surface of the male tooth 25a is tilted by a predetermined angle with respect to the axial direction to give a twist angle to the tooth surface of the male tooth 25a. I am trying.

However, even if the rattling of the male teeth 25a and the female teeth 26a in the circumferential direction can be suppressed in the serration fitting by the tooth surface alignment, as described above, the outer diameter of the shaft portion of the male teeth 25a is reduced. Since there is a radial clearance a between the surface and the inner diameter surface of the hub wheel of the female tooth 26a, it is difficult to suppress rattling in the radial direction.

Further, in the bearing device shown in FIG. 7, of the inner races 7 and 8 in the double row, the joint outer ring 4 of the constant velocity universal joint 3 is used.
Since the inner race 8 is formed on one side, the constant velocity universal joint 3 receives a bending moment as well as a torsion moment. When a bending moment is applied to the constant velocity universal joint 3 as described above, there is a problem in that the bending rigidity decreases due to radial rattling existing between the male teeth 25a and the female teeth 26a.

Therefore, the present invention has been proposed in view of the above problems, and an object of the present invention is to provide a diameter existing between a male tooth and a female tooth in which a hub wheel and a joint outer ring are serrated and fitted. It is an object of the present invention to provide a drive wheel bearing device capable of suppressing rattling in the direction and improving bending rigidity of a hub wheel, and a method for manufacturing the same.

[0013]

As a technical means for achieving the above-mentioned object, a drive wheel bearing device according to the present invention comprises a hub wheel, a double row bearing and a constant velocity universal joint as a unit. In a drive wheel bearing device in which a wheel and a constant velocity universal joint are fitted via a torque transmitting means, the torque transmitting means complementarily fits uneven portions provided on the hub wheel and the constant velocity universal joint. It is characterized in that a radial preload is applied to the uneven portion.

In the drive wheel bearing device according to the present invention, a radial preload is applied to the concavo-convex portions provided in the hub wheel and the constant velocity universal joint in a complementary state. As a result, radial rattling can be eliminated in the fitted state of the uneven portion. Here, when the torque transmission means is serration, it means that the male and female teeth which are the concave and convex portions provided on the hub wheel and the constant velocity universal joint respectively. It means a state in which they mesh with each other. Note that, as is well known, it is possible to adopt splines instead of serrations, so the term serration means serration or spline.

A preload in the radial direction is applied to the serration by adopting a structure in which at least one of the large diameter and the small diameter facing each other of the serrations provided on the hub wheel and the constant velocity universal joint is fitted with an interference fit. Can be granted. Here, the large diameter of the serration means the outermost diameter of the tooth profile that forms the serration, and the small diameter of the serration means the minimum diameter of the tooth profile that forms the serration. Further, if the male teeth of the serration have a helix angle with respect to the axis, it is possible to suppress the rattling of the male teeth and the female teeth in the circumferential direction.

According to the present invention, an outer ring having a vehicle body mounting flange on the outer periphery and a double row outer race formed on the inner periphery, and a wheel mounting flange on one end, and one of the double row inner races on the outer periphery. A hub wheel that directly forms the inner race,
A constant velocity universal joint having a joint outer ring integrally formed with the shaft portion and the other inner race on the outer periphery, a double row outer race of the outer ring and a double row of outer rings accommodated between the hub race and the inner race of the constant velocity universal joint. The present invention can be applied to a drive wheel bearing device of a type including a rolling element, and a structure in which a hub wheel is externally fitted to the shaft portion and the hub wheel and the joint outer ring are integrally fixed in a butted state. is there.

The method of manufacturing a bearing device for a drive wheel according to the present invention has a vehicle body mounting flange on the outer circumference, an outer ring having a double row outer race formed on the inner circumference, and a wheel mounting flange on one end, and the outer circumference. A constant velocity universal joint having a hub wheel in which one inner race of the double row inner race is directly formed, and a joint outer ring in which the other inner race is integrally formed on the shaft portion and the outer periphery, and a double row of the outer ring Outer race and a double row rolling element housed between a hub wheel and an inner race of a constant velocity universal joint, and the shaft portion is press-fitted into the hub wheel through serrations to which a preload is applied in the radial direction. In a method for manufacturing a drive wheel bearing device in which a wheel and a joint outer ring are fixed together in a butted state, the shaft portion is press-fitted into a hub wheel to finish the inner race, and then the hub wheel and the shaft portion are temporarily separated. After doing Degrees, wherein the fixed integrally in a state abutting the hub wheel and the joint outer ring on which is fitted the shaft portion into the hub wheel assembled rolling elements of the outer ring and double row.

In the method of the present invention, the shaft portion of the joint outer ring is press-fitted into the hub ring before the inner race finish processing of the hub ring and the joint outer ring to temporarily assemble them. Then, after finishing the inner race, the hub wheel and the shaft portion are pulled out and separated, and then the shaft portion is press-fitted into the hub wheel again to assemble the outer ring and the double row rolling element and then the hub wheel. The joint outer ring and the joint outer ring are fixed together. With this configuration, even if the shaft portion is press-fitted into the hub wheel via the serration that has been preloaded in the radial direction, it is possible to suppress the deformation of the inner race of the hub wheel due to the press-fitting of the shaft portion.

When assembling the hub wheel, the bearing and the constant velocity universal joint, it is desirable that the phases of the serrations of the hub wheel and the outer ring of the joint be matched.

[0020]

1 shows a bearing assembly for a drive wheel according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along the line BB of FIG. Hub wheel 1
Both serrations 35 and 36 are shown. The same parts as those in FIGS. 7 and 8 are designated by the same reference numerals.

In the bearing device for a drive wheel of this embodiment, the hub wheel 1, the double row bearing 2 and the constant velocity universal joint 3 are unitized, and the outer ring of the constant velocity universal joint 3 is joined to the inner periphery of the hub wheel 1. Four
It is equipped with a structure in which is press-fitted so that torque can be transmitted.

The bearing 2 comprises a double row of outer races 5, 6 and inner races 7, 8 and a double row of rolling elements 9, 10 assembled between the outer races 5, 6 and the inner races 7, 8. It is a double-row angular contact ball bearing configured. In this bearing device, one of the double-row inner races 7 and 8 is formed on the outer peripheral surface of the hub wheel 1, and the other inner race 8 is formed on the outer peripheral surface of the shoulder portion 11 of the joint outer ring 4. Has been done. Double row outer races 5 and 6 are outer ring 12
Is formed on the inner peripheral surface of the.

The hub wheel 1 has a wheel mounting flange 13 for mounting a wheel, and hub bolts (not shown) for fixing a wheel disk are planted at equal intervals in the circumferential direction of the wheel mounting flange 13. Has been done. Outer ring 12
Has a vehicle body mounting flange 14 for mounting on a vehicle body, and this vehicle body mounting flange 14 is fixed to a knuckle (not shown) extending from a suspension device of the vehicle body by a bolt.
The hub wheel 1 has a cylindrical shape, and a serration 36 is formed on a part of its inner peripheral surface.

The outer ring 12 is provided at the openings at both ends of the bearing 2.
A pair of seals 15 and 16 for sealing the annular spaces of the hub ring 1 and the joint outer ring 4 are fitted to the inner diameter of the end portion of the outer ring 12 so that the grease filled in the inside leaks and the water or foreign matter enters from the outside. It is designed to prevent

The constant velocity universal joint 3 is provided at one end of a shaft 17, and has a joint outer ring 4 having a track groove 18 formed on the inner peripheral surface thereof, and a track groove 19 opposed to the track groove 18 of the joint outer ring 4. The joint inner ring 20 formed on the surface, the ball 21 installed between the track groove 18 of the joint outer ring 4 and the track groove 19 of the joint inner ring 20, and the ball 21 interposed between the joint outer ring 4 and the joint inner ring 20. And a holder 22 for supporting the. The outer joint ring 4 includes a mouth portion 23 accommodating the inner joint ring 20, the ball 21 and the cage 22, and a shaft portion 24 axially integrally extending from the mouth portion 23 and having serrations 35 formed on the outer peripheral surface thereof. Have.

The shaft portion 24 of the joint outer ring 4 is press-fitted into the hub wheel 1, and the both are fitted by the serrations 35 and 36 provided on the outer peripheral surface of the shaft portion 24 and the inner peripheral surface of the hub ring 1, respectively, and torque is applied. It is possible to communicate. At this time, the preload of the bearing 2 is controlled by abutting the end surface 27 of the shoulder portion 11 of the joint outer ring 4 and the inboard side end surface 28 of the hub wheel 1. Further, by tightly press-fitting the root portion of the shaft portion 24 into the hub wheel 1, centering by the pilot portion 29 ensures the coaxiality between the hub wheel 1 and the joint outer ring 4. Then, the end portion of the shaft portion 24 is plastically deformed to the outer diameter side by, for example, swing caulking, and the caulking portion 30 is engaged with the outboard-side end surface 31 of the hub wheel 1 so that the joint outer ring 4 becomes a hub. It is fixed to the wheel 1, and the hub wheel 1, the bearing 2 and the constant velocity universal joint 3 are unitized.

In this bearing device, as shown in FIG. 2, the male teeth 35a of the serrations 35 formed on the shaft portion 24 and the female teeth 36a of the serrations 36 formed on the hub wheel 1 are made to have a large diameter, so that the shaft is formed. The portion 24 and the hub wheel 1 are fitted together. That is, the outermost diameter dimension of the male tooth 35a of the shaft portion 24 is set larger than the outermost diameter dimension of the female tooth 36a of the hub wheel 1, and the outer diameter surface 35b of the male tooth 35a is set to the inner diameter of the hub wheel between the female teeth 36a. By abutting against the surface 36b (matching with a large diameter), radial preload is applied to the serrations 35, 36. By applying the radial preload to the serrations 35 and 36 in this manner, radial rattling can be eliminated in the fitted state of the shaft portion 24 and the hub wheel 1.

In this embodiment, the large diameter matching structure is shown. However, the smaller inner diameter dimension of the male tooth 35a of the shaft portion 24 is set larger than the innermost dimension of the female tooth 36a of the hub wheel 1. It may be a structure.

In the bearing device of this embodiment, one inner race 8 is formed in the joint outer ring 4 of the constant velocity universal joint 3 of the double row inner races 7 and 8, so that the constant velocity universal joint 3 is A bending moment is also received at the same time as a torsion moment. However, even if a bending moment is applied to the constant velocity universal joint 3, the male teeth 35a and the female teeth 36a are in a state of being fitted to each other due to the large diameter matching.
Since radial rattling can be suppressed between and the female teeth 36a, the bending rigidity can be improved.

Here, as described above, the serrations 35 and 36 for adjusting the shaft portion 24 of the joint outer ring 4 to the hub wheel 1 with a large diameter.
In the case of adopting the structure in which the shaft portion 24 is fitted into the hub wheel 1 while the serrations 35, 36 are preloaded in the radial direction, the shaft portion 24 is formed on the outer peripheral surface of the hub wheel 1. The inner race 7 may be deformed.

Therefore, the shaft portion 24 of the joint outer ring 4 is attached to the hub ring 1.
When press-fitting into, the method detailed below is adopted.
First, as shown in FIG. 3, before the inner race finish processing of the hub wheel 1 and the joint outer ring 4, the shaft portion 24 of the joint outer ring 4 is attached to the hub wheel 1.
Press into and temporarily assemble both. Then, after the inner races 7 and 8 are finished, the hub wheel 1 and the shaft portion 24 are processed.
After pulling out and separating, the shaft portion 24 is fitted again to the hub wheel 1 while aligning the phases of the serrations 35 and 36, and the end portion 32 of the shaft portion 24 is caulked to the outer diameter side to make the compound with the outer ring 12. After assembling the rolling elements 9 and 10 in a row, the hub wheel 1 and the joint outer ring 4 are integrally fixed in a butted state. With this configuration, even if the shaft portion 24 is press-fitted into the hub wheel 1 through the serrations 35 and 36 that are preloaded in the radial direction, the inner race 7 of the hub wheel 1 is deformed by the press-fitting of the shaft portion 24. Can be suppressed.

On the other hand, in this serration fitting structure, as means for suppressing the rattling of the male teeth 35a and the female teeth 36a in the circumferential direction, the tooth surfaces of the male teeth 35a of the serrations 35 provided on the shaft portion 24 are provided. Is inclined by a predetermined angle with respect to the axial direction so that the tooth surface of the male tooth 35a has a helix angle, the rattling of the male tooth 35a and the female tooth 36a in the circumferential direction can be suppressed. it can.

However, in order to secure the coaxiality between the hub wheel 1 and the joint outer ring 4, in the bearing device having the centering structure by the pilot portion 29 (see FIG. 1), the base portion of the shaft portion 24 of the joint outer ring 4 is It is necessary to tightly press fit into the hub wheel 1. If the tightening margin of the pilot portion 29 is large, the inboard side inner diameter of the hub wheel 1 swells to the outer diameter side,
As a result, the tightening margins at the ends of the serrations 35 and 36 on the inboard side cannot be secured, and conversely, excessive stress is likely to occur at the ends of the serrations 35 and 36 on the outboard side.

Therefore, as in the embodiment shown in FIG. 4, the annular groove 3 is formed in the axially substantially central portion of the serration 35 of the shaft portion 24.
3 is formed, and the serration 35 is divided into two in the axial direction.
In this way, by fitting the shaft portion 24 of the joint outer ring 4 to the hub wheel 1 via the first serration portion 35 ′ and the second serration portion 35 ″, the tightening margin of the pilot portion 29 is large, When the root portion of the shaft portion 24 is tightly press-fitted into the hub wheel 1, even if the tightening margin of the inboard side end portion (portion shown in the figure) of the second serration portion 35 '' cannot be secured, other Three places, that is, the second serration part 3
5 ″ outboard side end (portion shown in the figure), first serration portion 35 ′ inboard side end (portion shown in the figure) and outboard side end (portion shown in the figure) Since the tightening margin can be secured by contacting with each other, an excessive stress does not occur in any part, the fitting stress generated in the inner diameter of the hub wheel 1 can be relieved, and the inner diameter of the hub wheel 1 can be reduced. Fatigue strength is improved, and scoring does not occur due to serration fitting.

The male teeth 35a of the shaft portion 24 and the female teeth 3 of the hub wheel 1
The magnitude of the twist angle at 6a may be the same or different between the first serration portion 35 'and the second serration portion 35''. In addition, as shown in FIG. 5A, the direction of the twist angle is set to the first serration portion 3
Even if 5 ′ and the second serration portion 35 ″ are the same, as shown in FIG.
5'and the second serration portion 35 '' may be reversed. Although the twist angles of the male teeth 35a and the female teeth 36a are greatly exaggerated in the figure for easy understanding, the actual twist angle is about 10 minutes. Even if the serration portion 35 ′ and the second serration portion 35 ″ are reversed, the shaft portion 24 can be press-fitted into the hub wheel 1.

In the above embodiment, one of the double row inner races 7 and 8 is formed on the outer peripheral surface of the hub wheel 1, and the other inner race 8 is formed on the outer joint surface of the constant velocity universal joint 3. Although the bearing device of the type directly formed on the outer peripheral surface of No. 4 has been described, the present invention is not limited to this and is also applicable to the bearing device of the type shown in FIG. 6, for example. In the bearing device of the embodiment shown in the figure, one of the inner races 7 and 8 of the double row is formed on the outer peripheral surface of the hub wheel 1, and the other inner race 8 is formed on the hub wheel 1.
The structure is formed on the outer peripheral surface of a separate inner ring 34 that is externally fitted to the end portion of the inboard side.

Also in this embodiment, the shaft portion 24 and the hub wheel 1 are fitted by serration by making the male teeth 35a of the shaft portion 24 and the female teeth 36a of the hub wheel 1 have a large diameter (FIG. 2). reference). That is, by setting the radial dimension m of the male tooth 35a of the shaft portion 24 to be larger than the radial dimension n of the female tooth 36a of the hub wheel 1, the outer diameter surface 35b of the male tooth 35a is set.
Are abutted against the inner diameter surface 36b of the hub wheel between the female teeth 36a (large-diameter matching), thereby preloading the serrations 35, 36 in the radial direction and fitting the shaft portion 24 and the hub wheel 1 in the radial direction. I try to eliminate the rattling.

Further, in this serration fitting structure, the tooth surface of the male tooth 35a is inclined at a predetermined angle with respect to the axial direction as means for suppressing rattling of the male tooth 35a and the female tooth 36a in the circumferential direction. By making the tooth surface of the male tooth 35a have a helix angle, rattling in the circumferential direction between the male tooth 35a and the female tooth 36a can be suppressed.

Also in this embodiment, an annular groove 33 is formed in a substantially central portion of the serration 35 of the shaft portion 24 in the axial direction to divide the serration 35 into two in the axial direction. In this type of bearing device, if the serration 35 is not divided into two, the axial dimension of the serration 35 is long. Therefore, if the male teeth 35a of the shaft portion 24 are provided with a helix angle, the end portion on the inboard side and the outboard side portion are formed. Since there is a tightening margin only at the side end portion, excessive stress is generated in the serrations 35 at the inboard side end portion and the outboard side end portion, which may reduce the fatigue strength of the inner diameter of the hub wheel 1. Further, when the shaft portion 24 is fitted into the hub wheel 1, there is a possibility that the serration fit may cause galling or the like.

Therefore, if the axial dimension of the serration 35 is long as in this type of bearing device, a means for dividing the serration 35 into two parts is effective. In this way, the first serration portion 35 'and the second serration portion 3
By fitting the shaft portion 24 of the joint outer ring 4 to the hub wheel 1 via 5 ″, the outboard side end portion (portion shown in the figure) and the inboard side end of the first serration portion 35 ′ are formed. Portion (portion shown in the figure), second serration portion 3
The 5 '' outboard side end (the part shown in the figure) and the inboard side end (the part shown in the figure) come into contact with each other at four places to secure the tightening allowance, so there is an excessive amount in either part. No stress is generated, the fitting stress generated in the inner diameter of the hub wheel 1 can be relaxed, the fatigue strength of the inner diameter of the hub wheel 1 is improved, and galling or the like does not occur due to serration fitting.

[0041]

In the bearing device for a drive wheel according to the present invention,
With the concave and convex portions provided on the hub wheel and the constant velocity universal joint complementarily fitted together, a radial preload is applied to the concave and convex portions, so It is possible to eliminate rattling, improve the bending rigidity of the hub wheel, and provide a high-quality drive wheel bearing device.

Further, in the manufacture of the drive wheel bearing device in which the hub wheel and the constant velocity universal joint are fitted in a state where a preload is applied in the radial direction, the shaft portion is press-fitted into the hub wheel to finish the inner race. After processing, temporarily separate the hub ring and the shaft part, then fit the shaft part to the hub ring again to assemble the outer ring and the double row rolling element, and then place the hub ring and the joint outer ring in abutment state. By integrally fixing, even if the shaft portion is press-fitted into the hub wheel through the serration that is preloaded in the radial direction, it is possible to suppress the deformation of the inner race of the hub wheel due to the press-fitting of the shaft portion.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a drive wheel bearing device according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line BB of FIG.

FIG. 3 is a cross-sectional view showing a state in which the hub wheel is temporarily assembled to the joint outer ring before the inner race finish processing of the hub wheel and the joint outer ring in the method for manufacturing a drive wheel bearing device according to the present invention.

FIG. 4 is a sectional view including a partially omitted portion showing a bearing device in which the serration of the shaft portion is divided into two in the axial direction in the embodiment of FIG. 1.

FIG. 5 (a) is a front view showing a shaft portion in which serrations are divided into two parts, and each part is provided with a twist angle in the same direction. (B) is a front view showing a shaft portion in which the serration is divided into two parts, and a twist angle in the opposite direction is provided in each part.

FIG. 6 is another embodiment of the present invention, which has a structure in which an inner race is formed on the outer peripheral surface of a separate inner ring that is externally fitted to the inboard side end portion of the hub wheel, and the serration of the shaft portion is set in the axial direction. FIG. 3 is a cross-sectional view including a partially omitted portion showing the bearing device divided into two parts.

FIG. 7 is a sectional view showing a conventional example of a drive wheel bearing device.

8 is an enlarged cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 hub wheel 2 bearings 3 constant velocity universal joint 4 Joint outer ring 5,6 outer race 7,8 Inner race 9,10 rolling elements 12 outer ring 13 Wheel mounting flange 14 Body mounting flange 24 Shaft 35,36 Torque transmission means (serration) 35a Concavo-convex part (male tooth) 36a Concavo-convex part (female tooth)

Continued front page    (72) Inventor Yoshihiro Ozawa             Entier, 1578 Higashi-Kaizuka, Iwata City, Shizuoka Prefecture             Nu Co., Ltd. (72) Inventor Hikaru Umekita             Entier, 1578 Higashi-Kaizuka, Iwata City, Shizuoka Prefecture             Nu Co., Ltd. (72) Inventor Hiroyuki Ogura             Entier, 1578 Higashi-Kaizuka, Iwata City, Shizuoka Prefecture             Nu Co., Ltd. F term (reference) 3J101 AA02 AA43 AA54 AA62 AA72                       BA53 BA54 BA56 BA65 DA16                       FA15 FA31 FA41 GA03 GA14

Claims (7)

[Claims] 1. A drive wheel bearing device in which a hub wheel, a double-row bearing and a constant velocity universal joint are unitized, and the hub wheel and the constant velocity universal joint are fitted through a torque transmitting means. The means complementarily fits the concave and convex portions provided on the hub wheel and the constant velocity universal joint, respectively, and applies a radial preload to the concave and convex portions. apparatus. 2. The drive wheel bearing device according to claim 1, wherein the torque transmission means are serrations provided on the hub wheel and the constant velocity universal joint, respectively. 3. The at least one of the large diameters and the small diameters of the serrations provided on the hub wheel and the constant velocity universal joint, which are opposed to each other, are fitted with an interference fit. Drive wheel bearing device. 4. The drive wheel bearing device according to claim 2, wherein the serrations provided on the constant velocity universal joint have a helix angle with respect to the shaft center. 5. An inner race having a vehicle body mounting flange on the outer periphery and a double row outer race formed on the inner periphery, and a wheel mounting flange on one end, and one inner race of the double row inner races on the outer periphery. A constant velocity universal joint having a hub wheel directly formed with a shaft portion and a joint outer ring integrally formed with the other inner race on the outer periphery of the shaft portion; 5. A double-row rolling element housed between races, wherein a hub wheel is externally fitted to the shaft portion, and the hub wheel and the joint outer ring are fixed together in a butted state. A bearing device for a drive wheel according to any one of 1. 6. An inner race having a vehicle body mounting flange on the outer periphery and a double row outer race formed on the inner periphery, and a wheel mounting flange on one end, and one inner race of the double row inner races on the outer periphery. A constant velocity universal joint having a hub wheel directly formed with a shaft portion and a joint outer ring integrally formed with the other inner race on the outer periphery of the shaft portion; A double row rolling element accommodated between races is provided, and the shaft portion is press-fitted into a hub wheel through serrations to which radial preload is applied, and the hub wheel and the joint outer ring are fixed together in a butted state. In the method for manufacturing a drive wheel bearing device described above, after the shaft portion is press-fitted into the hub wheel to finish the inner race, the hub wheel and the shaft portion are once separated, and then the shaft portion is fitted to the hub wheel again. Combined with the outer ring and double row A method of manufacturing a bearing device for a drive wheel, comprising assembling a rolling element, and integrally fixing a hub wheel and a joint outer ring in a butted state. 7. The method of manufacturing a bearing device for a drive wheel according to claim 6, wherein the phases of serrations of the hub wheel and the outer ring of the joint are matched when the hub wheel, the bearing and the constant velocity universal joint are assembled. .