JP2002195280A - Bearing unit for axle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sealing property of a connecting portion between a hub wheel and constant velocity joint in a bearing unit for an axle. SOLUTION: In the hub wheel 1 in which a double row rolling bearing 2 and a constant velocity joint 3 are installed, the connecting portion with the hub wheel 1 and a shaft portion 36 in an outer ring 31 of the constant velocity joint 3 is sealed by a sealing unit 7 so as to hide from the outside. Thus, muddy water and the like is not directly splashed to the connecting portion, and invasion of water to the connecting portion can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axle bearing device to which wheels are mounted.

[0002]

2. Description of the Related Art An example of a conventional axle bearing device is shown in FIG. In the figure, a hub unit of a type to which a drive wheel of an automobile is attached is exemplified as an axle bearing device. In the figure, 1 is a hub wheel, 2 is a double row rolling bearing, 3
Is a constant velocity joint.

In order to mount the double row rolling bearing 2 to the hub wheel 1, the inner end of the hub wheel 1 on the vehicle inner side is bent radially outward, so that the inner race of the double row rolling bearing 2 is mounted. Inner ring 24 on the side
It is caulked against the end face of. By this caulking, a required preload is applied to the double row rolling bearing 2.

[0004] Further, as a mode of connecting the outer ring 31 of the constant velocity joint 3 to the hub wheel 1, a shaft portion 36 of the outer ring 31 of the constant velocity joint 3 is spline-fitted into a hollow hole of the hub wheel 1. The hub wheel 1 is sandwiched between the nut 10 screwed to the small diameter thread portion of the shaft portion 36 and the bowl-shaped portion 35 of the outer ring 31 of the constant velocity joint 3 from both axial directions.

[0005]

In the above-mentioned conventional example, since muddy water or the like is directly applied between the caulking portion 14 and the bowl-shaped portion 35, moisture invades therefrom. There is a possibility that rust may be generated by penetrating to the spline fitting surface between the hollow hole of the hub wheel 1 and the shaft portion 36 of the outer race 31 of the constant velocity joint 3.

By the way, in the above structure,
If the fastening force of the nut 10 is too strong, the hub wheel 1
Since the caulking portion 14 is compressed and deformed, an extra load is applied to the double row rolling bearing 2, and the rolling characteristics are reduced and the life is shortened. It is necessary to carefully and carefully tighten the nut 10, resulting in poor workability.

On the other hand, the applicant of the present application has previously described the caulking portion 14 of the hub wheel 1 and the outer race 3 of the constant velocity joint 3.
1 has a structure in which the bowl-shaped portion 35 is brought into non-contact or light contact.

In this proposed technique, muddy water or the like is directly applied to the caulking portion 14 and the bowl-shaped portion 35. In such a case, the non-coupling of the caulking portion 14 and the bowl-shaped portion 35 is prevented. Moisture easily penetrates from the contact portion or the light contact portion, and penetrates into the spline fitting surface between the hollow hole of the hub wheel 1 and the shaft portion 36 of the outer ring 31 of the constant velocity joint 3, so that the above-described problem occurs. It can be said that it is more easily generated.

In view of such circumstances, an object of the present invention is to improve the sealing performance of a joint between a hub wheel and a constant velocity joint in an axle bearing device.

[0010]

According to the first axle bearing device of the present invention, a double row rolling bearing is mounted on the outer periphery of a hub wheel to which the wheel is mounted, and the constant velocity joint is mounted on the inner periphery of the hub wheel. The outer ring of the constant velocity joint is connected to the bowl-shaped portion in which the tilt guide element is housed, and the small diameter portion of the bowl-shaped portion, and is prevented from rotating in the circumferential direction with respect to the hub wheel. And a shaft portion coupled from the vehicle inner side, and straddles between the outer ring of the constant velocity joint and the outer ring of the double row rolling bearing, from the outside between the hub wheel and the outer ring of the constant velocity joint. A sealing device for concealing and sealing is provided.

The second axle bearing device according to the present invention includes the first axle bearing device.
Wherein the inner end of the hub wheel on the vehicle inner side is bent radially outward and crimped to the end face of the inner race of the vehicle inner side of the double row rolling bearing, and the swaged portion is a bowl in the outer ring of the constant velocity joint. It is characterized in that it is in a non-contact state or a lightly contact state with the shape part.

The third axle bearing device of the present invention is characterized in that:
Alternatively, in the second configuration, the sealing device is attached to a first ring attached to an outer ring of a double-row rolling bearing, and attached to a stepped portion of a bowl-shaped portion of an outer ring of a constant velocity joint. And a second annular body opposed in the axial direction with a minute gap therebetween.

The fourth axle bearing device of the present invention is characterized in that
Wherein the lip which is brought into contact with the other ring is provided on one of the rings.

A fifth axle bearing device according to the present invention is characterized in that
Alternatively, in the third configuration, the first ring body is attached to an outer ring of a double-row rolling bearing and extends a core metal of a seal ring that forms a contact sealing portion or a non-contact sealing portion with an inner ring side. Consisting of:

According to a sixth aspect of the present invention, there is provided the axle bearing device according to the first aspect.
In any one of the fifth to fifth configurations, the outer race of the double-row rolling bearing is provided with a vehicle body coupling flange, and a portion present on the vehicle inner side with respect to the outer ring is provided outside the outer race of the double-row rolling bearing. It is characterized in that it is set smaller than the diameter dimension.

In short, in the present invention, the joint between the hub wheel and the outer ring of the constant velocity joint is concealed from the outside by a sealing device and sealed. As a result, muddy water and the like do not need to be directly applied to the space between the hub wheel and the outer ring of the constant velocity joint, and it is possible to prevent moisture from entering there.

In particular, in the case of a structure in which the vehicle inner side of the hub wheel is caulked to the vehicle inner side inner ring of the double row rolling bearing as in the second configuration, the caulked portion is also externally sealed by the sealing device. Can be concealed. Moreover, in the second configuration, since the bowl-shaped portion of the outer race of the constant velocity joint is brought into non-contact or light contact with the swaged portion of the hub wheel, it is not necessary for the double row rolling bearing through the swaged portion. It is possible to prevent the axial load from being applied, which is advantageous in practicality.

In the third configuration, since the sealing device has a labyrinth structure, there is no need to increase the rotational torque.

Further, in the fourth configuration, since the contact portion is provided in the sealing device, the sealing performance is remarkably improved although the rotational torque is slightly increased.

Further, in the fifth configuration, since the sealing device uses a part of the seal ring attached to the double row rolling bearing, the equipment cost can be reduced.

In the sixth configuration, since the outer diameter of the outer ring bowl of the sealing device and the constant velocity joint is set to be smaller than the outer diameter of the outer ring of the double row rolling bearing, the axle bearing device is assembled. Thus, it is possible to realize a simple work form in which the mounting member is inserted into the through hole of the supporting member on the vehicle body side to be mounted and inserted from one side in the axial direction.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings.

FIGS. 1 to 3 show a first embodiment of the present invention. Here, as the axle bearing device, a hub unit to which a driving wheel of an automobile is attached is taken as an example. FIG. 1 is a sectional view showing an axle bearing device, and FIG.
FIG. 3 is an enlarged view of a portion surrounded by a circle in FIG.
FIG. 2 is a diagram showing an assembling process of FIG. 1.

The axle bearing device shown in FIG.
, A double row rolling bearing 2 and a constant velocity joint 3.

The hub wheel 1 has a hollow structure. A radially outward flange 11 is formed at an axially intermediate portion of an outer peripheral surface of the hub wheel 1, and a spline (not shown) is provided in a required area of the hollow hole. And a raceway surface 12 of a ball 22 group on the vehicle outer side of the double row rolling bearing 2 on the vehicle inner side of the flange 11 on the outer peripheral surface.

The double row rolling bearing 2 includes a single outer ring 21 having two rows of raceway grooves, a plurality of balls 22 as rolling elements arranged in two rows, two crowned cages 23, And an inner ring 24 related to the ball 22 group on the vehicle inner side,
The inner ring of the ball group 22 on the vehicle outer side does not exist because the raceway surface of the hub wheel 1 is used as described above.

The constant velocity joint 3 is a so-called known Zeppa type (Barfield type) constant velocity joint.
It is composed of Outer ring 31 is inner ring 32, ball 3
Bowl-shaped portion 35 in which the container 3 and the retainer 34 are stored and arranged
And a shaft portion 3 integrally connected to the small diameter side of the bowl-shaped portion 35.
6 is comprised. A spline is formed on the outer peripheral surface of the shaft portion 36, and the spline is fitted into the hollow hole of the hub wheel 1.

A double row rolling bearing 2 is mounted on the outer peripheral surface of the hub wheel 1. The inner end of the hub wheel 1 on the vehicle inner side is bent radially outward and is caulked to the inner side end surface of the inner race 24 of the double row rolling bearing 2. The caulking portion is denoted by reference numeral 14.

Further, the constant velocity joint 3 is connected to the hub wheel 1 in such a form as to be adjacent to the double row rolling bearing 2. This connection mode will be described later in detail.

Then, a disc rotor and wheels of a disc brake device (not shown) are applied to the flange 11 of the hub wheel 1 and mounted by a plurality of bolts 13. A radially outward flange 25 provided on the outer race 21 of the double row rolling bearing 2 is bolted to a vehicle body (not shown). Further, the shaft 5 is spline-fitted to the inner ring 32 of the constant velocity joint 3, and is fixed by a retaining ring (reference numeral omitted) or the like. The other end of the shaft 5 is attached to a differential device of the vehicle via another constant velocity joint (not shown).

In such an axle bearing device, the rotational power of the shaft 5 is transmitted to a wheel (not shown) attached to the hub wheel 1 via the constant velocity joint 3.

Next, a description will be given of a form in which the outer ring 31 of the constant velocity joint 3 is connected to the hub wheel 1 described above.

First, in the hollow hole of the hub wheel 1, a spline is formed only in the axially intermediate region, and the diameter of the spline in the vehicle inner side region and the vehicle outer side region is larger than the diameter of the groove bottom of the spline in the axially intermediate region. The enlarged diameter regions at both ends are cylindrical surfaces. The reference numeral 15 is assigned to the enlarged diameter region on the vehicle inner side, and the reference numeral 16 is assigned to the enlarged diameter region on the vehicle outer side.

A peripheral groove 37 is provided on the outer ring 31 of the constant velocity joint 3 at the end edge of the shaft portion 36.
The C-shaped retaining ring 6 is fitted into the peripheral groove 37 so as to partially protrude.

The shaft 36 of the outer race 31 of the constant velocity joint 3 is spline-fitted into the hollow hole of the hub wheel 1 from the vehicle inner side.
The inner end of the spline on the vehicle inner side is the hub wheel 1
When the spline abuts against the vehicle inner end portion, the C-shaped retaining ring 6 attached to the shaft portion 36 reaches the enlarged diameter region 16 on the vehicle outer side in the hollow hole, and the C-shaped retaining ring 6 Are spread radially outward and come into contact with the enlarged diameter region. As a result, the female spline of the hub wheel 1 is sandwiched between the vehicle inner side edge of the male spline of the shaft portion 36 and the C-shaped retaining ring 6 from both sides in the axial direction. Joint 3
Are connected inseparably.

In this state, it is controlled so that a required gap is formed between the caulking portion 14 and the bowl-shaped portion 35 of the outer race 31 of the constant velocity joint 3, and the caulking portion 14 is caulked. A load other than the applied axial force is not applied at all.

In the first embodiment, by providing a gap between the swaged portion 14 of the hub wheel 1 and the bowl-shaped portion 35 of the outer race 31 of the constant velocity joint 3, the preload applied to the double row rolling bearing 2 is provided. And the outer race 31 of the constant velocity joint 3 and the double row rolling bearing 2
A sealing device 7 that covers the caulked portion 14 of the hub wheel 1 from the outside and seals it is provided so as to straddle the outer ring 21 of the hub wheel 1 so that the gap is concealed from the outside and sealed. It is characterized by:

Sealing devices 8 and 9 are mounted on the vehicle outer side and the vehicle inner side of the double row rolling bearing 2.
The sealing device 8 on the vehicle outer side is mounted on the shoulder of the outer ring 21 to form a single seal ring. The sealing device 9 on the vehicle inner side includes a seal ring 91 mounted on the shoulder of the outer ring 21 and an inner ring. 24 is a pack seal in combination with a slinger 92 mounted on the shoulder. Each of the seal rings has a structure in which a plurality of lips are attached to the inner periphery of the annular cored bar.

The sealing device 7 includes two rings 71 and 72.
And a pack seal. First ring 71
Here, a part of the annular core of the seal ring 91 of the sealing device 9 on the inner side of the vehicle is linearly extended in the axial direction. Further, the second annular body 72 is formed in a U-shape, which is a double cylinder inside and outside in the radial direction, and is fixed to the bowl-shaped portion 35 of the outer ring 31 of the constant velocity joint 3 by press fitting. The first ring 71 is inserted between the inner and outer cylindrical portions of the second ring 72 in a non-contact state with a small gap therebetween. Is done.

If such a sealing device 7 is used, muddy water or the like is not directly applied to the periphery of the caulking portion 14 of the hub wheel 1, and the caulking portion 14 and the bowl-shaped portion 3 are not required.
5 through the gap between the hub wheel 1 and the constant velocity joint 3
It is possible to prevent moisture from intruding toward the spline fitting portion.

Since the sealing performance around the caulked portion 14 is thus enhanced, the bowl-shaped portion 35 of the constant velocity joint 3 may be brought into non-contact or light contact with the caulked portion 14 of the hub wheel 1. Axial load when the outer ring 31 of the constant velocity joint 3 is coupled to the hub wheel 1 and the outer ring 31 of the constant velocity joint 3 from a tripod joint (not shown) connected to the shaft 6
The axial load acting on the outer side of the vehicle does not need to act on the caulking portion 14 at all. Therefore, it is only necessary to apply the required preload to the double-row rolling bearing 2 only when the hub wheel 1 is crimped, so that the management is facilitated and the design is maintained as designed. Therefore, the rolling characteristics and the life of the double row rolling bearing 2 can be achieved as designed.
This is advantageous in practicality.

FIG. 4 is a sectional view showing an axle bearing device according to Embodiment 2 of the present invention. In the second embodiment, FIG.
1 is eliminated, and the configuration of the sealing device 7 shown in FIG. 1 is changed.

The sealing device 7A here is a first ring 71 fitted and mounted on the outer ring 21 of the double row rolling bearing 2 by press fitting.
A, and a second annular body 72A that is externally fitted and fixed to the bowl-shaped portion 35 by press-fitting.

The inner periphery of the first ring 71A is
A lip 73A that is brought into contact with the inner cylindrical portion of the annular body 72A is attached. A flange 74A is provided on the outer diameter side of the second ring body 72A so as to extend radially outward and face the first ring body 71A and the outer ring 21 of the double row rolling bearing 2 via a minute gap. Have been. This minute gap serves as a non-contact sealing portion.

According to the second embodiment, the same operation and effect as those of the first embodiment can be obtained.
The sealing device 9 on the vehicle inner side can be omitted, which is advantageous for cost reduction. Moreover, since the non-contact sealing portion is formed by making the flange 74A of the second ring 72A substantially radially opposed to the outer ring 21 in the radial direction, the relative position between the outer ring 21 and the second ring 72A is in the axial direction. This is advantageous in that the non-contact sealing portion can be stably secured even if it is displaced.

FIG. 5 is a sectional view showing an axle bearing device according to Embodiment 3 of the present invention. In the third embodiment, the sealing device 7B is a single seal ring.

The sealing device 7B has a structure in which a lip 73B which is brought into contact with the caulking portion 14 is attached to an inner peripheral portion of an annular body 72B which is externally fitted and fixed to the bowl-shaped portion 35 by press-fitting. Has become.

A flange 74B extending radially outward and facing the slinger 92 of the sealing device 9 and the outer ring 21 of the double-row rolling bearing 2 via a small gap is provided on the outer diameter side of the ring 72B. Is provided. This minute gap serves as a non-contact sealing portion.

According to the third embodiment, the same operation and effect as those of the first embodiment can be obtained.

FIG. 6 is a sectional view showing an axle bearing device according to Embodiment 4 of the present invention. In the fourth embodiment, the sealing device 7C composed of a single slinger is connected to the constant velocity joint 3.
And a sealing device 9A comprising a single seal ring is mounted on the inner side of the double row rolling bearing 2 on the vehicle inner side.

The sealing device 7C here is an annular body of metal or the like in which one axial end portion of the inner and outer cylindrical portions in the radial direction is connected by an annular plate portion, and the inner cylindrical portion is a bowl shape of the constant velocity joint 3. Part 35
Is externally fitted and fixed to the small-diameter side step portion by press-fitting.

The sealing device 9A is provided on the inner peripheral portion of the annular cored bar.
The radial lip 93a is brought into contact with the outer peripheral surface of the inner ring 24, and the axial lip 93b is brought into contact with the annular plate of the sealing device 7C.

The annular core of the sealing device 9A is protruded toward the vehicle inner side along the axial direction, and this protruding portion has a small diameter with respect to the outer cylindrical portion of the sealing device 7C via a small gap. Facing each other. This minute gap serves as a non-contact sealing portion.

According to the fourth embodiment, the same operation and effect as those of the first embodiment can be obtained.

The present invention is not limited to the above-described first to fourth embodiments, and various modifications and applications are possible.

(1) In each of the above embodiments, various modifications are conceivable for the connection between the hub wheel 1 and the constant velocity joint 3. For example, without using the C-shaped retaining ring 6 shown in the first to third embodiments, a small-diameter screw portion or a screw hole is provided at the shaft end of the shaft portion 36, and a nut or a bolt is attached thereto. A nut or a bolt may be abutted against the end face of the hub wheel 1 on the vehicle outer side.

(2) In each of the above embodiments, the outer ring 31 of the constant velocity joint 3 is
Although the bowl-shaped portion 35 is managed in a non-contact state, it may be managed in a contact state. Even in that case, when connecting the constant velocity joint 3 to the hub wheel 1,
Since almost no load is applied to the caulked portion 14, the preload applied to the double row rolling bearing 2 at the time of caulking is kept substantially unchanged. The present invention can also be applied to the structure presented in the conventional example.

(3) In each of the above embodiments, in order to simplify the work of attaching the hub unit to a support member 17 (refer to FIG. 6) called a knuckle or a carrier on the vehicle body in a state where the hub unit is assembled, a constant velocity joint is used. Outer ring 31 of 3
It is preferable that the outer diameter of the bowl-shaped portion 35 and the sealing devices 7, 7A, 7B, 7C is set smaller than the outer diameter of the outer ring 21 of the double row rolling bearing 2. Specifically, as a procedure for attaching the hub unit to the support member 17, first, the bowl-shaped portion 35 of the constant velocity joint 3 in the hub unit is inserted into the through hole 17 a provided in the support member 17 from the vehicle outer side. After inserting, double row rolling bearing 2
In the outer ring 21, the inner side region of the vehicle with respect to the radially outward flange 25 is fitted into the through hole 17 a of the support member 17 with a required interference, and at the axial middle of the outer ring 21 of the double row rolling bearing 2. The provided radially outward flange 25 is brought into contact with the support member 17. The flange 25 and the support member 17 are connected by bolts 18. In this process, the shaft 5 is connected to the inner ring 32 of the constant velocity joint 3. It is considered that such mounting work is the simplest, but in order to allow this work, the outer diameter of the bowl-shaped portion 35 of the constant velocity joint 3 and the outer diameters of the sealing devices 7, 7A, 7B, and 7C are set. The dimension is set smaller than the outer diameter dimension of the outer ring 21 of the double row rolling bearing 2. Assuming that the sealing devices 7, 7A, 7B, 7
If the outer diameter of C is set to be larger than the outer diameter of the outer race 21 of the double row rolling bearing 2, the above-described mounting work cannot be performed, so that another mounting work needs to be devised. In that sense, the sealing devices 7 and 7C presented in the first and fourth embodiments do not hinder the illustration, but the outer diameters of the sealing devices 7A and 7B presented in the second and third embodiments are double-row rolling. It is preferable that the outer diameter of the outer ring 21 of the bearing 2 be set smaller than the outer diameter.

[0059]

According to the first to sixth aspects of the present invention, the joint between the hub wheel and the outer ring of the constant velocity joint is concealed from the outside by a sealing device and sealed, whereby the hub wheel and the outer ring of the constant velocity joint are connected. Since muddy water and the like are not directly applied to the space, it is possible to prevent water from entering there. Therefore, it is possible to contribute to the improvement of product reliability over a long period of time, for example, by protecting the connection portion from rust.

In particular, in the case where the vehicle inner side of the hub wheel is caulked to the vehicle inner side inner ring of the double row rolling bearing as in the second aspect of the invention, the caulked portion is also externally sealed by the sealing device. Concealed from the surface, and the intrusion of moisture into the caulked portion can be prevented. Moreover, in the second aspect of the present invention, since the bowl-shaped portion of the outer ring of the constant velocity joint is brought into non-contact or light contact with the swaged portion of the hub wheel, it is necessary for the double row rolling bearing through the swaged portion. Axial load that is not applied can be prevented. As a result, the required preload can be applied to the double row rolling bearing only when the hub wheel is caulked, so that the preload applying operation is simplified, and the preload for the double row rolling bearing can be appropriately maintained for a long period of time. , It can achieve its rolling characteristics and life as designed,
This is advantageous in practicality.

According to the third aspect, since the sealing device has a labyrinth structure, it is not necessary to increase the rotational torque.

According to the fourth aspect, since the contact portion is provided in the sealing device, the sealing performance is remarkably improved although the rotational torque is slightly increased.

According to the fifth aspect, the sealing device uses a part of the seal ring attached to the double row rolling bearing, so that the equipment cost can be reduced.

Further, if the outer diameter of the outer ring bowl of the sealing device or the constant velocity joint is set smaller than the outer diameter of the outer ring of the double row rolling bearing, the axle bearing device is assembled. In this state, it is possible to realize a simple work mode in which the mounting member is inserted into the through-hole of the support member on the vehicle body side to be mounted and is mounted from one side in the axial direction.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an axle bearing device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion surrounded by a circle in FIG. 1;

FIG. 3 is a view showing an assembling process of FIG. 1;

FIG. 4 is a sectional view showing an axle bearing device according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing an axle bearing device according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing an axle bearing device according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a conventional axle bearing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hub wheel 14 swaged portion of hub wheel 15 enlarged diameter portion of hub wheel 2 double row rolling bearing 24 inner ring of double row rolling bearing 3 constant velocity joint 31 outer ring of constant velocity joint 35 bowl shape section of outer ring 36 shaft section of outer ring 7 Sealing device 71 First ring of sealing device 72 Second ring of sealing device

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Keisuke Nomura 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. F-term (reference) 3J016 AA01 BB02 CA02 CA06 3J101 AA02 AA43 AA54 AA62 AA72 GA02

Claims (6)

[Claims] An axle bearing device wherein a double row rolling bearing is mounted on an outer periphery of a hub wheel to which a wheel is mounted, and a constant velocity joint is mounted on an inner periphery of the hub wheel. An outer ring, a bowl-shaped portion in which the tilt guide element is stored, and a shaft portion connected to the small-diameter portion of the bowl-shaped portion and coupled from the vehicle inner side in a state of being prevented from rotating in the circumferential direction with respect to the hub wheel. A sealing device is provided to straddle between the outer race of the constant velocity joint and the outer race of the double row rolling bearing, and conceal and seal the space between the hub wheel and the outer race of the constant velocity joint from the outside. A bearing device for an axle. 2. The axle bearing device according to claim 1, wherein a vehicle inner shaft end of the hub wheel is bent and deformed radially outward and is caulked to an end surface of a vehicle inner side inner ring of the double row rolling bearing. A bearing device for an axle, wherein a caulking portion is in a non-contact state or a lightly contact state with a bowl-shaped portion of an outer ring of a constant velocity joint. 3. The axle bearing device according to claim 1, wherein the sealing device is provided on a first ring attached to an outer ring of the double row rolling bearing and a stepped portion of a bowl-shaped portion of the outer ring of the constant velocity joint. A bearing device for an axle, comprising: a second ring body attached and opposed to the first ring body in the axial direction with a small gap therebetween. 4. The axle bearing device according to claim 3, wherein one of said rings is provided with a lip which is brought into contact with the other ring. 5. The axle bearing device according to claim 2, wherein the first ring is mounted on an outer ring of a double-row rolling bearing to form a contact sealing portion or a non-contact sealing portion with an inner ring side. A bearing device for an axle, characterized in that the bearing is formed by extending a core of a seal ring. 6. The axle bearing device according to any one of claims 1 to 5, wherein a flange for connecting the vehicle body is provided on an outer ring of the double-row rolling bearing, and a portion located closer to the vehicle inner side than the flange. Is set smaller than the outer diameter of the outer race of the double row rolling bearing.