JP2007192342A - Bearing unit for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing unit for a vehicle which can reduce production cost and bears a large load capacity to an acting load. <P>SOLUTION: The bearing unit is equipped with an inner shaft 1, an outer ring 2 to sheathe the inner shaft 1, and a first rolling body 3 on the inner side and a second rolling body 4 on the outer side which are provided in two rows between the inner shaft 1 and the outer ring 2. Furthermore, the unit is equipped with an inner ring member 5 having an inner ring raceway for the first rolling body 3 which is provided so as to sheathe the inner side of the inner shaft 1; and a caulking part 6 which is formed by enlarging the outer circumference side of the end 1a at the inner side of the inner shaft 1, and fixes the inner ring member 5 to the inner shaft 1 not to pop out. The unit is composed of a ball which is provided so that the first rolling body 3 on the inner side contacts angularly to the inner ring member 5 and the outer ring 2, and the second rolling body 4 on the outer side is composed of a tapered roller. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle bearing device.

  What is known as a bearing device for a vehicle is, for example, as in Patent Document 1, provided in two rows between an inner shaft, an outer ring provided so as to be fitted on the inner shaft, and the inner shaft and the outer ring. Some have first and second rolling elements. Then, an inner ring member having a raceway surface for the first rolling element is fitted on the inner side (inner side) of the inner shaft, and a raceway surface for the second rolling element is formed on the outer peripheral surface of the intermediate portion of the inner shaft, A flange portion for attaching the wheel side member to the outer side (outer side) end portion of the inner shaft is provided. The first rolling element on the inner side is composed of a plurality of tapered rollers. The inner ring member having the raceway surface for the first rolling element has an inclined circumferential surface whose raceway surface is inclined with respect to the axial center, and further has a circumferential flange portion for receiving the acting axial load. Have. The inner ring member is secured to the inner shaft by a retaining ring member fitted in a concave circumferential groove provided on the outer peripheral surface of the inner shaft.

JP-A-11-91308 (FIG. 1)

The bearing device described in Patent Document 1 uses a retaining ring member that is a separate member for fixing the inner ring member, and further includes a member for preventing the retaining ring member from falling off. In many cases, the assembly becomes complicated, which increases the production cost. Further, as shown in the sectional view of the inner ring member 52 in FIG. 2, conventionally, the outer peripheral side of the end portion of the inner shaft 51 is widened outwardly to form a caulking portion 55, and the caulking portion 55 forms the inner ring. A configuration is known in which the member 52 is secured and secured. However, when this caulking portion 55 is applied to the bearing device described in Patent Document 1, the inner ring member 52 that is externally fitted to the inner shaft 51 is deformed by a load during caulking, and is indicated by a two-dot chain line in FIG. As described above, there is a problem that the inclination angle of the raceway surface 53 of the inner ring member 52 and the heel angle of the heel portion 54 change. When the inclination angle of the raceway surface 53 changes, the contact state with the tapered rollers changes and an appropriate line contact cannot be obtained. Further, if the flange angle changes, the flange portion 54 cannot come into contact with the end surface of the tapered roller at the surface, and it may not be possible to receive a load while sliding against the end surface of the tapered roller.
For this purpose, it is conceivable that the inner ring member 52 has an initial shape with a predetermined deformation amount so as to have a predetermined shape and angle after caulking. However, this operation is very difficult, which increases production costs and may cause variations in product dimensions.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a bearing device that can reduce the production cost, has a large load capacity with respect to an applied load, and has high rigidity.

  In order to achieve the above object, a bearing device according to the present invention includes an inner shaft, an outer ring provided so as to be fitted on the inner shaft, and an inner side provided in two rows between the inner shaft and the outer ring. A first rolling element and an outer side second rolling element, an inner ring member having an inner ring raceway for the first rolling element provided to be fitted on the inner side of the inner shaft, and an inner side end of the inner shaft And a caulking portion formed so that the inner ring member is secured to the inner shaft and fixed to the inner shaft. It is constituted by a ball provided so as to be in angular contact with the inner ring member and the outer ring which are externally fitted to a shaft, and the second rolling element on the outer side is constituted by a tapered roller. Yes.

According to the bearing device having such a configuration, the first rolling element on the inner side and on the caulking portion side is configured by a ball provided so as to be in angular contact with the inner ring member and the outer ring on the inner shaft side. Therefore, it is possible to allow deformation of the raceway surface of the inner ring member caused by a load when forming the caulking portion. That is, even if the direction of the raceway surface of the arc-shaped cross section of the inner ring member slightly changes due to caulking, it is possible to maintain an appropriate contact state between the balls that are rolling elements and the inner ring member and the outer ring. it can. Thereby, the load capacity with respect to the load in the radial direction and the load capacity with respect to the load in the axial direction are not impaired. That is, when the rolling element on the caulking portion side is a tapered roller bearing as in the prior art, even if the inclination angle of the raceway surface of the inner ring member changes even slightly, it becomes impossible to make a line contact with the tapered roller. If the angle of the collar portion of the inner ring member changes even slightly, the contact surface of the collar portion cannot slide while sliding against the end surface of the tapered roller. Trouble that occurs. However, the present invention does not cause these troubles.
Moreover, since the 2nd rolling element by the side of the flange part which is an outer side is made into the tapered roller, it can receive the load of a radial direction and an axial direction, and can enlarge load capacity further. Accordingly, the rigidity of the entire bearing device can be increased.

Furthermore, the inner side end of the inner shaft is caulked and the inner ring member is externally fitted and fixed to the inner shaft, eliminating the need for a separate retaining ring member and reducing the number of parts. Can be simplified and the production cost can be reduced.
Further, when the bearing device is attached to the vehicle, the side on which the angular ball bearing is configured is the inner side (inside), and the side on which the tapered roller bearing is configured is the outer side (outside). In the bearing device for a vehicle, for example, when the vehicle is turned, a load acting on the outer side becomes larger than that on the inner side. Therefore, in the bearing device of the present invention, a tapered roller bearing having a large load capacity is configured on the outer side, and an angular ball bearing having a smaller load capacity than the tapered roller bearing is configured on the inner side. A bearing device with a good balance of capacity can be obtained.

According to the wheel bearing device of the present invention, since the inner ring member is fixed by caulking of the inner side end portion of the inner shaft, the manufacture is simplified and the production cost can be reduced. By configuring the angular ball bearing, deformation of the raceway surface due to caulking can be allowed, so that the load capacity in the bearing portion is not reduced. Moreover, by having a tapered roller bearing, the load capacity with respect to the load which acts on a bearing apparatus can be enlarged.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing a bearing device according to an embodiment of the present invention. This bearing device can be used as a bearing device for a wheel in an automobile. The bearing device includes an inner shaft 1, an outer ring 2 provided so as to be fitted on the inner shaft 1, and an inner shaft 1 and an outer ring 2. The inner side first rolling elements 3 and the outer side second rolling elements 4 provided in two rows are provided.

Further, the bearing device includes an inner ring member 5 and a caulking portion 6 that prevents the inner ring member 5 from being fixed to the inner shaft 1. The inner ring member 5 has an inner ring raceway for the first rolling element 3 formed on the outer circumferential surface thereof, and the caulking portion 6 is configured such that the outer circumferential side portion of the inner side end 1a of the inner shaft 1 is expanded radially outward. It is formed by plastic deformation.
The inner shaft 1 has the caulking portion 6 formed at the inner side end portion 1a, and has a radially outer flange portion 7 for attaching a wheel side member to the outer side end portion 1b. Although not shown, the wheel side member includes a wheel of a wheel and a brake rotor of a disc brake device.

The inner shaft 1 has a smaller diameter portion 8 on the inner side, a middle diameter portion 9 formed to have a larger diameter than the smaller diameter portion 8 in the middle portion in the axial center direction, and a larger diameter than the middle diameter portion 9 on the outer side. The inner shaft 1 has a stepped shape. Further, between the small diameter portion 8 and the medium diameter portion 9, there is a radially outward stepped surface portion 10 that is orthogonal to the axis. The inner ring member 5 is externally fitted to the small diameter portion 8. The inner ring member 5 is sandwiched between the cut surface portion 10 and the caulking portion 6 from both sides in the axial direction, and the caulking portion 6 presses the side end surface of the inner ring member 5. Further, the large-diameter portion 13 and the base portion of the flange portion 7 serve as a sealing surface of a sealing member 14 provided at the inner peripheral end portion of the outer ring 2.
The outer ring 2 is provided coaxially with the inner shaft 1 and has a cylindrical portion 11 having two rows of outer ring raceway surfaces on the inner peripheral surface, and a radially outer flange portion 12 connected to the vehicle body side member. The flange portion 12 is provided on the outer peripheral surface of the cylindrical portion 11.

  The inner-side first rolling element 3 that is the caulking portion 6 side is constituted by a ball provided so as to be in angular contact with the inner ring member 5 and the outer ring 2 that are externally fitted to the inner shaft 1, and The second rolling element 4 on the outer side which is the flange portion 7 side is constituted by a tapered roller. Therefore, the inner ring member 5 has an inner ring raceway surface for the first rolling element 3 constituted by balls, the raceway surface has a circular arc shape, and the curvature radius of the raceway surface is set larger than the radius of the ball. Yes. The outer ring raceway surface for the first rolling element 3 formed on the inner peripheral surface of the cylindrical portion 11 of the outer ring 2 has a circular arc shape in cross section, and the radius of curvature of this raceway surface is set larger than the radius of the ball. ing. The straight line connecting the contact point between the ball and the raceway surface of the inner ring member 5 and the contact point between the ball and the raceway surface of the outer ring 2 forms a predetermined angle with respect to the radial direction that is perpendicular to the axis. The angular ball bearing is comprised in the 1st rolling element 3 side which is an inner side.

  And the inner ring raceway surface for the 2nd rolling elements 4 comprised by the tapered roller is formed in the intermediate diameter part 9 of the inner shaft 1. FIG. The inner ring raceway surface is formed as a concave circumferential groove in the medium diameter portion 9, and the raceway surface that contacts the circumferential surface of the tapered roller is a tapered circumferential surface that increases in diameter toward the outer side of the inner shaft 1. And the outer ring raceway surface for the 2nd rolling elements 4 is formed in the inner peripheral surface of the cylinder part 11 of the outer ring | wheel 2, and the tapered roller bearing is comprised in the 2nd rolling element 4 side which is an outer side.

  The first rolling element 3 made up of a plurality of balls that make angular contact with the outer ring 2 and the inner ring member 5 and the second rolling element 4 made up of a plurality of tapered rollers constitute a two-row bearing device. These are arranged so as to face each other along the axial direction so as to receive loads from both sides in the central direction. Further, when the vehicle turns, a larger radial load and axial load act on the axle opposite to the turning direction (that is, on the left side of the vehicle when turning right). Therefore, the bearing device having two rows of bearing portions according to the present invention has the first rolling element 1 in which the bearing portion on the inner side is constituted by balls, and the bearing portion on the outer side is constituted by tapered rollers. The outer rolling element 4 has a larger load capacity than the inner bearing part. Thereby, a bearing device with a good balance of load capacity can be obtained.

In addition, the wheel bearing device of the present invention is not limited to the illustrated form, and may be another form within the scope of the present invention. In the above embodiment, the inner shaft 1 rotates with respect to the outer ring 2. Although it is set as the bearing apparatus for driven wheels made free, this invention is applicable also as a bearing apparatus for drive wheels although illustration is abbreviate | omitted.
In the above embodiment, the outer ring raceway surface on the outer side is formed integrally (directly) on the inner diameter portion 9 of the inner shaft 1. However, as with the inner side, the inner ring raceway surface on the outer side is formed on the inner shaft. It is good also as a structure which formed in the inner ring member separate from 1, and fitted this to the inner shaft 1. FIG.

1 is a longitudinal sectional view showing a bearing device according to an embodiment of the present invention. It is principal part sectional drawing explaining the conventional bearing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner shaft 1a Inner side edge part 1b Outer side edge part 2 Outer ring 3 1st rolling element 4 2nd rolling element 5 Inner ring member 6 Caulking part

Claims (1)

  An inner shaft, an outer ring provided so as to be fitted to the inner shaft, an inner-side first rolling element and an outer-side second rolling element provided in two rows between the inner shaft and the outer ring; The inner ring member having an inner ring raceway for the first rolling element provided so as to be fitted on the inner side of the inner shaft, and the outer peripheral side of the inner side end portion of the inner shaft are formed to be expanded radially outward. A vehicular bearing device including an inner ring member that is secured to the inner shaft to prevent the inner ring member from coming off; and the inner ring member and the outer ring that the inner first rolling element is externally fitted to the inner shaft. A bearing device for a vehicle comprising: a ball provided so as to be an angular contact, wherein the second rolling element on the outer side is constituted by a tapered roller.

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