JP2002161924A - Bearing device for axle shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a drag against draft on a caulking part in a bearing device for an axle shaft. SOLUTION: The cylinder part on the free end of shaft 1, where the rolling bearing 2 with R chamfering 24a at the inside diameter corner part of the inner ring 24 is installed to the outside, is bended for outside of the diametrical direction and the bearing device fixes the rolling bearing 2 to the shaft 1 not to be draught by caulking along R chamfering 24a of the inner ring 24. Forming the corner part of inside diameter side on the caulking parts 14 into the conical shape that the diameter enlarges gradually for outside of the shaft direction, the location of minimum diameter of this conical surface 14a is arranged for outside of the shaft direction even more than the inner ring edge face in this bearing device. Such form of the caulking part 14 means that the inside diameter side corner part of the caulking part 14 got finished without plastical deformation in the process of caulking and can keep the thickness of inside diameter side corner part, namely the thickness between the conical surface 14a of caulking part and the inside diameter corner part of the inner ring 24, almost equally before caulking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an axle bearing device. As the axle bearing device, for example, a hub unit of an automobile is exemplified.

[0002]

2. Description of the Related Art As an example of a conventional axle bearing device, there is U.S. Pat. No. 5,490,732, which has a structure as shown in FIGS.

In the drawing, reference numeral 80 denotes a hub wheel, 81 denotes a double-row rolling bearing such as a double-row outward-facing angular ball bearing, and 82 denotes a caulking portion.

The free end of the hub wheel 80 is bent radially outward by rolling caulking, and caulked against the end surface of the inner ring 83 of the double row rolling bearing 81, so that the double row rolling bearing 81 is attached to the hub wheel 80. It is fixed to keep it from falling off.

The overall shape of the outer end surface of the caulked portion 82 is a rounded curved surface. In addition, the radius of curvature R of the inner diameter side corner portion of the caulking portion 82 is the radius of curvature r of the so-called R chamfer at the inner peripheral surface corner portion of the inner ring 83.
It is set larger than.

[0006]

In the above conventional example,
If the free end of the hub wheel 80 can be made thicker than the predetermined thickness d1, as shown by the imaginary line in FIG. 8, the thickness of the inner diameter side corner of the caulked portion 82 can be kept thick, so there is no problem. , The free end of the hub wheel 80 has a thickness d2 less than a predetermined value.
When it is necessary to reduce the thickness, as shown by the solid line in FIG. 8, the inner diameter side corner of the caulked portion 82 is plastically deformed in a stretched form, so that the thickness becomes too thin and the radius of curvature R becomes large. Because it is too much, the rigidity of the caulked portion 82 itself tends to be insufficient. For this reason, the drag against the pull-out load acting on the double-row rolling bearing 81, that is, the pulling-out drag, such as the caulking portion 82 falling down and moving away from the end surface of the inner ring 83 due to the reaction force of the axial force applied to the double-row rolling bearing 81 by caulking, Run short.

[0007] In view of such circumstances, an object of the present invention is to improve the pull-out resistance of a swaged portion in an axle bearing device.

[0008]

SUMMARY OF THE INVENTION A first axle bearing device according to the present invention is characterized in that a free end side cylindrical portion of a shaft body on which a rolling bearing provided with an R chamfer at an inner ring inner corner portion is externally fitted is radially outwardly mounted. The rolling bearing is fixed to the shaft body by being bent in the direction and caulking along the R chamfer of the inner ring of the rolling bearing, and the inner diameter side corner of the caulking portion is gradually outward in the axial direction. It is formed in a conical shape whose diameter increases, and the minimum diameter position of this conical surface is arranged axially outside the inner ring end surface.

[0009] The second axle bearing device of the present invention comprises the first axle bearing device.
Wherein the angle formed between the conical surface and the shaft body center line is set in a range of 20 to 80 degrees.

The third axle bearing device of the present invention is characterized in that
Alternatively, in the second configuration, the corner on the minimum diameter side and the corner on the maximum diameter side of the conical surface are each formed into a curved surface, and the curved surface has a radius of curvature smaller than the radius of curvature of the chamfer at the inner diameter side corner of the inner ring. Is set to.

In short, according to the present invention, the inner diameter side corner of the caulked portion is not a curved surface but a conical surface. In the case of such a shape, in the caulking process of bending the free end of the shaft body, it means that the inner diameter side corner portion did not have to be plastically deformed into a stretched shape, and the thickness of the caulked portion The thickness between the conical surface and the inner-diameter-side corner of the inner ring can be maintained substantially equal to that before crimping. For this reason, the rigidity of the caulked portion is improved, and the caulked portion is prevented from falling down from the end surface of the inner ring after caulking.

In particular, when the inclination angle of the conical surface provided on the caulking portion is defined within a required range as in the second configuration, the thickness of the inner diameter side corner portion, that is, the conical surface of the caulking portion and the inner ring side of the inner ring are formed. This is advantageous in increasing the thickness between the corners as much as possible.

Further, if the end of the conical surface in the caulking portion is formed into a curved shape as in the third configuration, excessive stress does not act on a local portion of the caulking portion in the caulking process, and a small crack such as a micro-crack can be prevented. Occurrence is avoided.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on embodiments shown in the drawings. Here, a hub unit of a type used for driving wheels of an automobile is taken as an example of the axle bearing device.

FIG. 1 to FIG. 4 show an embodiment of the present invention. 1 is a longitudinal sectional view showing an axle bearing device, FIG. 2 is an enlarged view of a caulked portion, FIG. 3 is a longitudinal sectional view of a caulking jig for obtaining the caulked portion of FIG. 1, and FIG. It is explanatory drawing which shows the rolling caulking form using the caulking jig of No.3.

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, and a radially outward flange 11 is formed at an axially intermediate portion of an outer peripheral surface thereof. 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 raceways, a plurality of balls 22 as rolling elements arranged in two rows, two crowned retainers 23, It is a double-row outward-facing angular ball bearing composed of an inner ring 24 for a group of balls 22 on the vehicle inner side, and the inner wheel of the group of balls 22 on the vehicle outer side has a hub wheel 1 as described above.
Does not exist because it uses the orbital surface of

The constant velocity joint 3 is called a well-known Zeppa type (Barfield type) constant velocity joint, and includes an outer ring 31, an inner ring 32, a ball 33, and a retainer.
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.

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 the wheels (not shown) attached to the hub wheel 1 via the constant velocity joint 3.

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 from the R chamfer 24a of the inner peripheral surface corner of the inner race 24 of the double row rolling bearing 2 to the inner end side of the vehicle. ing. The caulking portion is denoted by reference numeral 14.

Further, a constant velocity joint 3 is connected to the hub wheel 1 so as to be adjacent to the double row rolling bearing 2. That is, in the hollow hole of the hub wheel 1, a spline is formed only in the axially intermediate region,
The vehicle inner side region and the vehicle outer side region are formed on a cylindrical surface whose diameter is larger than the diameter of the groove bottom of the spline in the axially intermediate region. The reference numeral 15 is assigned to the diameter-increased area on the vehicle inner side, and the reference numeral 16 is assigned to the diameter-increased area on the vehicle outer side.
Is attached to each. A circumferential groove 37 is provided on the outer ring 31 of the constant velocity joint 3 on the edge side of the shaft portion 36. The C-shaped retaining ring 6 is fitted into the peripheral groove 37 so as to partially protrude. And hub wheel 1
The shaft 36 of the outer ring 31 of the constant velocity joint 3 is spline-fitted from the vehicle inner side into the hollow hole of the constant velocity joint 3. When the C-shaped retaining ring 6 comes into contact with the side end portion, the C-shaped retaining ring 6 mounted on 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 faces outward in the radial direction. And comes into contact with the enlarged diameter region. Thus, the spline of the hub wheel 1 is sandwiched between the vehicle inner side edge of the spline of the shaft portion 36 and the C-shaped retaining ring 6 from both sides in the axial direction. 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. The gap may be eliminated by abutting the bowl-shaped portion 35 of the constant velocity joint 3 against the caulking portion 14.

In this embodiment, the shape of the swaged portion 14 of the hub wheel 1 is characterized, and will be described below.

That is, as shown in FIG.
Is formed in a conical surface 14a whose diameter gradually increases toward the vehicle inner side. The position of the minimum diameter in the conical surface 14a is located closer to the vehicle inner side than the perpendicular g along the end surface of the inner ring 24 of the double row rolling bearing 2.

The angle θ between the conical surface 14a and the central axis O of the hub wheel 1 is set in the range of 20 to 80 degrees.

The corner on the minimum diameter side and the corner on the maximum diameter side of the conical surface 14a are respectively curved surfaces 14b and 14b.
14c. The radii of curvature r1 and r2 of the curved surfaces 14b and 14c are set smaller than the radius of curvature r of the so-called R chamfer 24a in the shape of an arc at the inner corner of the inner ring 24.

The outer surface of the caulking portion 14 is provided with a flat surface 14d extending radially outward, and the length of the flat surface 14d in the radial direction is determined based on the vehicle to which the axle bearing device is to be used. Is specified as appropriate depending on the type of the device.

Next, a method of forming the above-described caulking portion 14 will be described. First, the inner race 24 of the double row rolling bearing 2 is externally fitted to the outer periphery of the free end side of the hub wheel 1, and then the same rolling end as described in the related art is applied to the free end of the hub wheel 1. You just have to do it.

However, the shape of the tip of the caulking jig 40 used for rolling caulking here must be as shown in FIG.

More specifically, in the caulking jig 40 shown in the figure, a convex portion 41 is formed at the center of the distal end surface, and an annular concave portion 42 is formed on the outer periphery of the convex portion 41. On the inner diameter side of the annular depression 42, an inclined surface 43 that is inclined by a required angle θ1 with respect to a virtual plane L along the radial direction is provided.
On the outer diameter side of the annular depression 42, an inclined surface 44 inclined by a required angle θ2 is provided. The inclination angles θ1 and θ2 of these inclined surfaces 43 and 44 are set in a relationship of θ1> θ2. However, the inner peripheral edge of the inclined surface 43 on the inner diameter side is formed into a curved surface, and this curved surface is set to a radius of curvature r2 corresponding to the curved surface 14c on the largest diameter side of the conical surface 14a in the caulking portion 14.

Then, as shown in FIG. 4, the tip of the caulking jig 40 as described above is applied to the free end of the hub wheel 1, and the caulking jig 40 is rolled around the dashed line P, so that the required When the angle α is set, a caulked portion 14 having a shape as shown in FIG. 2 can be obtained.

That is, by rolling the caulking jig 40, the entire shape of the caulking portion 14 is determined by the annular depression 42 of the caulking jig 40. Specifically, in the final stage of the rolling caulking, the conical surface 14 a is formed at the inner diameter side corner of the caulking portion 14 with the inclined surface 43 on the inner diameter side of the caulking jig 40, and the caulking portion 14 is formed at the bottom surface of the annular depression 42. A flat portion 14d is formed in the middle of the outer end surface in the radial direction, and the caulking portion 1 is further formed by the outer diameter side inclined surface 44.
An inclined surface 14e is formed on the outer diameter side of the outer end surface of the outer end surface 4. The curved surface 14b on the minimum diameter side of the caulking portion 14 is used for the caulking jig 40 at the final stage of caulking.
Is formed by sloping with the inclined surface 43 and the chamfer 43a on the inner diameter side.

That is, in the caulking form of the conventional example, as the thickness of the free end of the hub wheel 1 is reduced, the inner corner portion of the caulking portion 14 is plastically deformed in such a manner as to be extended toward the outer diameter side. Therefore, the thickness of the inner diameter side corner portion is likely to be reduced. However, if the caulking jig 40 of this embodiment is used, the inner diameter side corner portion of the caulking portion 14 is plastically expanded. Since it is difficult to deform, the thickness of the inner corner portion, that is, the conical surface 14a of the caulked portion 14 and the inner ring 2
The thickness between the inner diameter side corner and the inner diameter side 4 can be maintained substantially equal to that before crimping. For this reason, the rigidity of the caulked portion 14 is sufficient, and the caulked portion 14 does not fall down and separate from the inner ring 24 after caulking. Therefore, the pull-out drag of the double row rolling bearing 2 is increased as compared with the conventional example.

It should be noted that the present invention is not limited to the above-described embodiment, and various applications and modifications are conceivable.

That is, in the above-described embodiment, the axle bearing device used for the drive shaft of an automobile has been described as an example. However, the present invention is also applied to an axle bearing device used for a driven shaft of an automobile as shown in FIG. Can be applied. This axle bearing device has a structure in which the constant velocity joint 3 is not attached to the hub wheel 1. Therefore, the hub wheel 1 is solid and only the free end on the vehicle inner side is formed in a cylindrical shape. This is bent radially outward and is caulked against the inner ring of the double row outward angular ball bearing 2. In addition, since the configuration according to the features of the present invention is the same as that of the above embodiment, the description thereof is omitted.

[0038]

According to the first to third aspects of the present invention, by modifying the shape of the inner diameter side corner of the swaged portion, the thickness of the inner diameter side corner of the swaged portion can be maintained substantially equal to that before the swage. Therefore, the caulked portion can be maintained in a state in which the caulked portion is in close contact with or close to the outer end surface of the inner race, and the drag force of the caulked portion can be made sufficient. This is particularly advantageous when the thickness of the cylindrical free end of the shaft body is reduced.

In particular, when the inclination angle of the conical surface provided in the caulking portion is defined within a required range as in the invention according to the second aspect, the thickness of the inner diameter side corner portion of the caulking portion, that is, the conical surface of the caulking portion This is advantageous in increasing the thickness between the inner ring and the inner diameter side corner as much as possible.

Further, if the end of the conical surface in the caulking portion is formed into a curved shape as in the invention according to the third aspect, excessive stress does not act on the local portion of the caulking portion in the caulking process, and the micro-crack can be prevented. Is avoided.

[Brief description of the drawings]

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

FIG. 2 is an enlarged view of a caulked portion in FIG. 1;

FIG. 3 is a longitudinal sectional view of a caulking jig for obtaining a caulked portion in FIG. 2;

FIG. 4 is an explanatory view showing a rolling caulking mode using the caulking jig of FIG. 3;

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

FIG. 6 is a longitudinal sectional view of a conventional axle bearing device.

FIG. 7 is an enlarged view of a caulked portion in FIG. 6;

FIG. 8 is a diagram showing a defect in the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hub wheel 2 Double row rolling bearing 24 Inner ring of bearing 14 Caulking part of hub wheel 14a Conical surface of caulking part 14b Curved surface of conical surface on minimum diameter side 14c Curved surface of conical surface on maximum diameter side θ Conical surface inclination angle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichiro Kashiwagi 3-5-8 Minamisenba, Chuo-ku, Osaka City Inside Koyo Seiko Co., Ltd. (72) Inventor Tadashi Tadashi 3-5-8 Minamisenba, Chuo-ku, Osaka City Koyo Seiko F term in the company (reference) 3J017 AA02 DA01 DB08

Claims (3)

[Claims] A free end side cylindrical portion of a shaft body on which a rolling bearing provided with an R-chamfer at an inner-ring inner-diameter corner portion is externally mounted is bent radially outward to form the R-chamfer of the inner ring of the rolling bearing. A bearing device for an axle in which a rolling bearing is fixed to a shaft body by being caulked along, and an inner diameter side corner portion of the caulked portion is formed in a conical shape whose diameter gradually increases outward in the axial direction. A bearing device for an axle, wherein the minimum diameter position of the conical surface is disposed axially outside the inner ring end surface. 2. The axle bearing device according to claim 1, wherein an angle between the conical surface and a center axis of the shaft body is 20 to 8 degrees.
A bearing device for an axle, which is set in a range of 0 degrees. 3. The axle bearing device according to claim 1, wherein a minimum diameter side corner and a maximum diameter side corner of the conical surface are respectively curved surfaces, and the curved surfaces are inner diameter side corners of the inner ring. Wherein the radius of curvature is set to be smaller than the radius of curvature of the chamfer.