JP2009248788A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of aligning a portion in the axial spline engaging region of the central hole of a hub spindle and a central shaft of a constant velocity joint outer ring on the same central axis and reducing machining cost. <P>SOLUTION: The central hole 14 of the hub spindle 13 of a hub wheel 10 on which a wheel is mounted, is engaged with the central shaft 62 projected from an end face of the outer ring 60 of the constant velocity joint 50 in the axial spline engaging region W1 so that torque can be transferred therebetween. Out of both peripheral faces of an inner peripheral face of the central hole 14 and an outer peripheral face of the central shaft 62, one peripheral face includes a smooth engaging part 92 without spline teeth formed in one portion in the axial direction of the spline engaging region W1. Teeth tip faces of spline teeth on the other peripheral face is engaged with the smooth engaging part 92 in a press-fit state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wheel in which a center hole of a hub shaft of a hub wheel to which a wheel is attached and a center shaft protruding from an end surface of an outer ring of a constant velocity joint are fitted so that torque can be transmitted in an axial spline fitting region. The present invention relates to a bearing device.

In this type of wheel bearing device, a female spline is formed in the inner peripheral surface axial direction of the center hole of the hub shaft of the hub wheel, and the outer peripheral surface axial direction of the central shaft protrudes from the end surface of the outer ring of the constant velocity joint. Is formed with a male spline corresponding to the female spline.
Then, the female spline of the hub shaft of the hub wheel and the male spline of the central shaft of the outer ring of the constant velocity joint are spline-fitted so that torque can be transmitted, and the tip of the central shaft is caulked radially outward, or The outer ring of the constant velocity joint and the hub shaft are integrally connected by tightening a fastening nut at the tip of the central shaft.
In addition, as a wheel bearing device in which the center hole of the hub shaft of the hub wheel and the center shaft protruding from the end face of the outer ring of the constant velocity joint are fitted so as to transmit torque in the axial spline fitting region, For example, it is disclosed in Patent Document 1 and the like.
Japanese Patent Laid-Open No. 9-96317

By the way, in the wheel bearing device described above, in order to align the center hole of the hub shaft and the center shaft of the outer ring of the constant velocity joint on the same center line, it is necessary to cope with spline large diameter matching.
For this reason, the tooth tip surface of each spline tooth constituting the male spline of the center shaft and the tooth bottom surface of each spline tooth constituting the female spline of the center hole of the hub shaft are raised over the entire axial length of the spline fitting region. Polishing must be performed with precision, and the tooth tip surface and the tooth bottom surface must be brought into contact with each other to be spline-fitted, which requires a lot of labor and time and increases costs.

  In view of the above-described problems, the object of the present invention is to align the center line on the same center line in a part of the axial direction of the spline fitting region between the center hole of the hub shaft and the center axis of the outer ring of the constant velocity joint. An object of the present invention is to provide a wheel bearing device capable of reducing the processing cost.

To achieve the above object, a wheel bearing device according to a first aspect of the present invention includes a center hole of a hub shaft of a hub wheel to which a wheel is attached, and a center shaft protruding from an end surface of an outer ring of a constant velocity joint. Is a wheel bearing device fitted so that torque can be transmitted in the axial spline fitting region,
One of the peripheral surfaces of the inner peripheral surface of the center hole and the outer peripheral surface of the central shaft has a smooth fitting portion that has no spline teeth on a part of the spline fitting region in the axial direction. Formed,
The tip surface of the spline tooth on the other peripheral surface and the smooth fitting portion are fitted in a press-fitted state.

According to the above configuration, in a part of the axial direction of the spline fitting region between the central hole on the hub shaft side and the central shaft on the constant velocity joint side, the smooth fitting portion formed on one circumferential surface and the other circumferential surface The hub shaft and the center axis of the outer ring of the constant velocity joint can be centered on the same center line by fitting the tip surfaces of the spline teeth in a press-fitted state.
For this reason, it is not necessary to polish both male and female splines with high accuracy over the entire axial length of the spline fitting region, and the processing cost can be reduced.

The wheel bearing device according to claim 2 is the wheel bearing device according to claim 1,
The smooth fitting part is formed by a large diameter hole part formed in a part of the axial direction of the spline fitting region of the center hole,
A large-diameter male spline portion having a tooth tip surface fitted in the inner peripheral surface of the large-diameter hole portion in a press-fit state is formed in a part of the axial direction of the male spline of the central shaft. And

  According to the above configuration, the hub shaft and the central axis of the outer ring of the constant velocity joint are fitted by fitting the large-diameter hole portion of the central hole and the tooth tip surface of the large-diameter male spline portion of the central shaft in a press-fit state. Can be centered on the same center line.

The wheel bearing device according to claim 3 is the wheel bearing device according to claim 1,
The smooth fitting portion is formed by a smooth shaft portion formed in a part of the axial direction of the spline fitting region of the central shaft,
A small-diameter female spline portion having a tooth tip surface that is fitted into the outer peripheral surface of the smooth shaft portion in a press-fit state is formed in a part of the axial direction of the spline fitting region of the center hole. To do.

  According to the above configuration, the hub shaft and the central shaft of the outer ring of the constant velocity joint are concentric with each other by fitting the smooth shaft portion of the central shaft and the tooth tip surface of the small-diameter female spline portion of the central hole in a press-fit state. Can be centered on the line.

  Next, the best mode for carrying out the present invention will be described with reference to examples.

Example 1
A first embodiment of the present invention will be described with reference to FIGS.
1 is a longitudinal sectional view showing a wheel bearing device according to Embodiment 1 of the present invention. FIG. 2 is an enlarged longitudinal sectional view showing a spline fitting region of both male and female splines between the central hole of the hub shaft of the hub wheel and the central shaft of the outer ring of the constant velocity joint. FIG. 3 is a longitudinal sectional view showing a state where the hub wheel and the constant velocity joint are separated.

As illustrated in FIG. 1, the wheel bearing device according to the first embodiment includes a hub wheel 10, a double row angular ball bearing 20 as a rolling bearing, and a constant velocity joint 50. As the constant velocity joint 50, a well-known constant velocity joint called a Zepper type or a bar field type is used, and an inner ring 52 integrally connected to an outer peripheral surface of one end of the drive shaft 51, an outer ring 60, The plurality of balls 53 disposed between the inner and outer rings 52 and 60 and a holder 54 for holding the plurality of balls 53 are provided.
Further, a central shaft 62 for connecting the hub wheel 10 and the constant velocity joint 50 integrally is projected at the center of the end wall portion 61 of the outer ring 60 of the constant velocity joint 50. A cylindrical portion 67 for forming a caulking portion 68 is formed at the distal end portion of the central shaft 62.

  The hub wheel 10 integrally has a cylindrical hub shaft 13 and a flange 11 formed on the outer peripheral surface near one end of the hub shaft 13. A plurality of hub bolts 12 for attaching a wheel (not shown) with a brake rotor (not shown) interposed therebetween are fixed to the flange 11 at a predetermined pitch and by press-fitting.

  The outer ring 30, a plurality of balls 41, 42 as rolling elements and the cages 45, 46 are straddled across the outer peripheral surface of the hub axle 13 of the hub wheel 10 and the outer peripheral surface of the end wall portion 61 of the outer ring 60 of the constant velocity joint 50. The double row angular ball bearing 20 provided is assembled.

  That is, in the first embodiment, a raceway surface 22 corresponding to one raceway surface 31 of the outer ring 30 is formed on the outer peripheral surface of the hub shaft 13 closer to the flange 11, and the end wall of the outer ring 60 of the constant velocity joint 50 is formed. A raceway surface 23 corresponding to the other raceway surface 32 of the outer ring 30 is formed on the outer peripheral surface of the portion 61.

A center shaft 62 protruding from the center of the end wall portion 61 of the outer ring 60 of the constant velocity joint 50 is spline-fitted into the center hole 14 penetrating in the center of the hub shaft 13 of the hub wheel 10 so that torque can be transmitted. ing. The cylindrical portion 67 at the tip of the central shaft 62 is caulked radially outward along the outer surface of the hub shaft 13 to form a caulking portion 68, so that the hub shaft 13 and the constant velocity joint 50 can be connected. The outer ring 60 is fastened integrally so as to be able to transmit torque.
That is, a female spline 90 is formed in the inner peripheral surface axial direction of the center hole 14 of the hub shaft 13, and a male spline corresponding to the female spline 90 is formed in the outer peripheral surface axial direction of the central shaft 62 of the outer ring 60 of the constant velocity joint 50. A spline 80 is formed.

As shown in FIG. 3, the outer diameter (tip surface diameter) dimension A of the male spline 80 is smaller than the valley diameter dimension B of the female spline 90, and the valley diameter dimension C of the male spline 80 is equal to the female spline 90. Is set smaller than the inner diameter (tooth tip surface diameter) dimension D.
Further, of the male and female splines 80 and 90, one spline, for example, each spline tooth constituting the male spline 80 is formed in a spiral shape with an appropriate lead angle set in the circumferential direction, and in the axial direction. It extends.
Moreover, each spline tooth | gear which comprises the female spline 90 as the other spline is extended in parallel with the axial direction.
As a result, the side surface of the axial end portion of each spline tooth constituting the male spline 80 comes into contact with the side surface of each spline tooth constituting the female spline 90 to transmit torque, and the intermediate portion is in a non-contact state.

As shown in FIGS. 1 and 2, the center hole 14 of the hub shaft 13 and the center shaft 62 of the outer ring 60 of the constant velocity joint 50 are centered in the spline fitting region W1 by both male and female splines 80 and 90. One of the peripheral surfaces of the inner peripheral surface of the hole 14 and the outer peripheral surface of the central shaft 62 has a smooth fitting portion having no spline teeth in a part of the spline fitting region W1 in the axial direction. The tip surface of the spline teeth on the other peripheral surface and the smooth fitting portion are fitted in a press-fitted state.
In the first embodiment, as shown in FIG. 3, the smooth fitting portion is formed by a large-diameter hole portion 92 formed in a part of the axial direction of the spline fitting region W <b> 1 of the center hole 14.
On the other hand, a part of the central shaft 62 in the axial direction of the male spline 80 has an outer diameter F slightly larger than the inner diameter E of the large-diameter hole 92 and has an inner periphery of the large-diameter hole 92. A large-diameter male spline portion 82 having a tooth tip surface that is fitted into the surface in a press-fit state is formed.
Furthermore, the inner peripheral surface of the large-diameter hole portion 92 and the tooth tip surface (outer-diameter surface) of the large-diameter male spline portion 82 are processed with high accuracy by polishing or the like.

Further, in Example 1, when the load of one ball 41 of the angular ball bearing 20 acts in the direction of arrow P in FIG. Part) 92 and the large-diameter male spline part 82 are received by the press-fitting part, and the position in the press-fitting part axial direction is set.
Further, the press-fitting portion of the large-diameter hole portion 92 and the large-diameter male spline portion 82 is an axially intermediate portion where the side surfaces of the spline teeth of both the male and female splines 80 and 90 are in a non-contact state (non-contact state). The contact area is set so as not to hinder torque transmission.
Further, the outer diameter dimension G of the cylindrical portion 65 at the tip of the central shaft 62 is set smaller than the inner diameter (tip surface diameter) dimension D of the spline 90.

The wheel bearing device according to the first embodiment is configured as described above.
Therefore, as shown in FIG. 2, the male spline 80 of the center shaft 62 of the outer ring 60 of the constant velocity joint 50 is inserted while meshing with the female spline 90 of the center hole 14 of the hub shaft 13 of the hub wheel 10. After the joining, the cylindrical portion 67 at the tip of the central shaft 62 is caulked radially outward along the vehicle outer end surface of the hub shaft 13 to form a caulking portion 68, so that the speed is the same as that of the hub shaft 13. The outer ring 60 of the joint 50 is fastened integrally so as to transmit torque (see FIG. 1).

A large-diameter hole portion 92 of the center hole 14 in a part of the spline fitting region W1 formed by both male and female splines 80 and 90 between the center hole 14 of the hub shaft 13 and the center shaft 62 of the outer ring 60 of the constant velocity joint 50. And the tooth tip surface of the large-diameter male spline portion 82 of the center shaft 62 are fitted in a press-fitted state, whereby the hub shaft 13 and the center shaft 62 of the outer ring 60 of the constant velocity joint 50 are centered on the same center line. Can be combined.
For this reason, it is not necessary to polish both male and female splines with high accuracy over the entire axial length of the spline fitting region W1, and the processing cost can be reduced.

(Example 2)
Next, a second embodiment of the present invention will be described with reference to FIGS.
FIG. 4 is an enlarged longitudinal sectional view showing a spline fitting region of both male and female splines between the center hole of the hub shaft of the wheel bearing device according to the second embodiment of the present invention and the center shaft of the outer ring of the constant velocity joint. FIG. FIG. 5 is a longitudinal sectional view showing a state in which the hub wheel and the constant velocity joint are separated. FIG. 6 is an explanatory view showing an initial state of meshing of both male and female splines.

As shown in FIGS. 4 to 6, in the wheel bearing device according to the second embodiment, the center hole 114 of the hub shaft 13 of the hub wheel 10 and the center shaft 162 of the outer ring 60 of the constant velocity joint 50 are male. -The smooth fitting part provided in the spline fitting area | region W2 by both female splines 180 and 190 is arrange | positioned at the center axis | shaft 162 side.
That is, the smooth fitting portion is a smooth shaft formed in a part of the axial direction of the spline fitting region W2 of the central shaft 162 (a length portion of the half of the spline fitting region W2 on the distal end side of the central shaft 162). The portion 182 is formed. The outer diameter dimension J of the smooth shaft portion 182 is set smaller than the outer diameter (tip surface diameter) dimension K of each spline tooth of the male spline 180 and larger than the valley diameter dimension L, and the inner diameter of the female spline 190. (Tooth tip surface diameter) It is set slightly smaller than the dimension M.
On the other hand, the outer diameter of the smooth shaft portion 182 is formed in a part of the axial direction of the spline fitting region W2 of the center hole 114 (a length part of the outer side of the center hole 114 about half the length of the spline fitting region W2). An inner diameter dimension slightly smaller than the dimension and having a tooth tip surface fitted in the outer peripheral surface of the smooth shaft portion 182 in a press-fit state, and an inner diameter (tip surface diameter) dimension M of a general portion of the female spline 190 A small-diameter female spline portion 192 having a smaller inner diameter dimension N is formed.
Further, the outer peripheral surface of the smooth shaft portion 182 and the tooth tip surface (inner diameter surface) of the small-diameter female spline portion 192 are processed with high accuracy by polishing or the like.

Further, in Example 2, when the load of one ball 41 of the angular ball bearing 20 is applied in the direction of the arrow P in the figure during the rotation of the bearing, the load of the ball 41 is converted into a smooth shaft portion (smooth fitting portion). The position of the press-fit fitting portion is set so as to be received by the press-fit fitting portion between 182 and the small-diameter female spline portion 192.
Further, in the second embodiment, a cylindrical portion 165 for forming a caulking portion 166 at the tip of the smooth shaft portion 182 extends coaxially, and the outer diameter R of the cylindrical portion 165 is equal to the smooth shaft portion. It is set smaller than the outer diameter dimension J of 182 and the inner diameter dimension N of the small-diameter female spline portion 192.

In the second embodiment, the smooth shaft portion 182 of the center shaft 162 is inserted into the predetermined length portion of the one end of the female spline 190 of the center hole 114 before the center shaft 162 is pressed into the small-diameter female spline portion 192. In order to mesh and guide the male spline 180 and the female spline 190 of the center hole 14, the tooth tip surface is deleted by a predetermined amount to increase the inner diameter dimension S, and the meshing guide portion 200 is formed in that portion. Yes. As a result, both the male and female splines 180 and 190 between the center hole 114 of the hub shaft 13 and the center shaft 162 of the outer ring 60 of the constant velocity joint 50 are easily meshed with each other without being poorly meshed. 182 is press-fitted into the small-diameter female spline portion 192.
Since other configurations of the second embodiment are configured in the same manner as the first embodiment, the same components are denoted by the same reference numerals, and description thereof is omitted.

Therefore, in the second embodiment, the outer peripheral surface of the smooth shaft portion 182 of the central shaft 162 and the tooth tip surface of the small-diameter female spline portion 192 of the central hole 114 are fitted in a press-fit state, The center axis 162 can be centered on the same center line.
For this reason, it is not necessary to polish both male and female splines with high accuracy over the entire axial length of the spline fitting region W2, and the processing cost can be reduced.

The present invention is not limited to the first and second embodiments.
For example, in the first and second embodiments, the cylindrical portion 65 (165) at the tip of the central shaft 62 (162) is caulked outward in the radial direction to form the caulking portion 66 (166), thereby forming the hub shaft 13. The outer ring 60 of the constant velocity joint 50 and the outer ring 60 of the constant velocity joint 50 are integrally connected. However, a male screw is formed at the tip of the central shaft, and a fastening nut is fastened to the male screw to tighten the hub shaft and the outer ring of the constant velocity joint. The present invention can also be carried out when the two are connected together.
Moreover, in the said Example 1 and 2, although the case where the double row angular ball bearing was employ | adopted as a rolling bearing was illustrated, this invention can be implemented even if it uses a double row tapered roller bearing other than an angular ball bearing. It is.

It is a longitudinal cross-sectional view which shows the wheel bearing apparatus which concerns on Example 1 of this invention. Similarly, it is a longitudinal sectional view showing an enlarged spline fitting region of both male and female splines between the central hole of the hub shaft of the hub wheel and the central shaft of the outer ring of the constant velocity joint. It is a longitudinal section showing the state where a hub wheel and a constant velocity joint were separated similarly. In the longitudinal cross-sectional view which expands and shows the spline fitting area | region of both male and female splines with the center hole of the hub shaft of the wheel bearing apparatus which concerns on Example 2 of this invention, and the center axis | shaft of the outer ring | wheel of a constant velocity joint. is there. It is a longitudinal section showing the state where a hub wheel and a constant velocity joint were separated similarly. It is explanatory drawing which similarly shows the initial state of meshing of both male and female splines.

Explanation of symbols

10 Hub Wheel 13 Hub Shaft 14, 214 Center Hole 20 Angular Contact Ball Bearing (Rolling Bearing)
50 constant velocity joint 60 outer ring 62, 262 central shaft 80, 280 male spline 82 large diameter male spline part 90, 290 female spline 92 large diameter hole (smooth fitting part)
182 Smooth shaft part (smooth fitting part)
192 Small diameter female spline

Claims (3)

A wheel bearing device in which the center hole of the hub axle of the hub wheel to which the wheel is attached and the center axis protruding from the end face of the outer ring of the constant velocity joint are fitted so that torque can be transmitted in the axial spline fitting area. There,
One of the peripheral surfaces of the inner peripheral surface of the center hole and the outer peripheral surface of the central shaft has a smooth fitting portion that has no spline teeth on a part of the spline fitting region in the axial direction. Formed,
A wheel bearing device, wherein a tip surface of a spline tooth on the other peripheral surface and the smooth fitting portion are fitted in a press-fitted state. The wheel bearing device according to claim 1,
The smooth fitting part is formed by a large diameter hole part formed in a part of the axial direction of the spline fitting region of the center hole,
A large-diameter male spline portion having a tooth tip surface fitted in the inner peripheral surface of the large-diameter hole portion in a press-fit state is formed in a part of the axial direction of the male spline of the central shaft. Wheel bearing device. The wheel bearing device according to claim 1,
The smooth fitting portion is formed by a smooth shaft portion formed in a part of the axial direction of the spline fitting region of the central shaft,
A small-diameter female spline portion having a tooth tip surface that is fitted into the outer peripheral surface of the smooth shaft portion in a press-fit state is formed in a part of the axial direction of the spline fitting region of the center hole. Wheel bearing device.

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