JP2007269066A - Rolling bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device for a wheel capable of preventing deformation of a bearing ring and generation of creep even if a large load is applied and preventing a rotation failure and deterioration of service life by reducing the weight of the device. <P>SOLUTION: The rolling bearing device for a wheel has an inner shaft 4 and the bearing ring 3 through a rolling element 2 inside the inner periphery of an outer ring member 1. The bearing ring 3 has a chamfered part 5 in both ends of the inner periphery, and has a fitting surface A to be fitted on the inner shaft 4 between both the chamfered parts. A part of the inner shaft 4 corresponding to the only fitting part A of the bearing ring 3 is formed into a solid structure part 7, and other parts except the solid structure part is formed into hollow structure parts 9. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel rolling bearing device.

  As shown in FIG. 2, the rolling bearing device used to support the wheel on the vehicle body generally has an outer ring member 1 in which double-row outer raceway surfaces 1 a and 1 b are formed on the inner periphery, and the outer ring member 1. And an inner shaft 4 formed with a first inner raceway surface 4a facing one outer raceway surface 1a of the outer ring member 1 on the outer periphery. Further, the bearing ring 3 is fitted to the outer peripheral surface of the inner shaft 4 in an interference fit state, and has a second inner raceway surface 3a facing the other outer raceway surface 1b of the outer ring member 1 on the outer periphery. It has. A rolling element 2 is provided between the outer raceway surfaces 1a and 1b and the first and second inner raceway surfaces 4a and 3a. Further, a vehicle body mounting flange 11 is formed on the outer periphery of the outer ring member 1 so as to protrude radially outward. Normally, all the inner shafts 4 have a solid structure, but some have a hollow structure on the vehicle outer side in order to reduce weight (for example, see Patent Document 1).

Japanese Patent Laying-Open No. 2003-206967 (page 7, FIG. 1)

  With the recent demand for weight reduction of components, further reduction in weight is desired for the wheel rolling bearing device described in Patent Document 1. Thus, for example, in the wheel rolling bearing device shown in FIG. 2, it is conceivable that the inner shaft 4 is entirely hollow, but in this case, the rigidity of the inner shaft 4 is reduced. For this reason, when a large load is applied, the race 3 is deformed together with the inner shaft 4. As a result, abnormal vibration may occur, or the second inner raceway surface 3a of the race 3 may be peeled off at an early stage, and the service life may be reduced. Further, with the deformation of the inner shaft 4 and the bearing ring 3, so-called creep may occur in which the inner shaft 4 and the bearing ring 3 rotate relative to each other. Then, due to the occurrence of creep, there is a risk that a rolling failure will occur in the wheel rolling bearing device or its life may be reduced.

  The present invention has been made in view of the above-described problems, and achieves weight reduction as compared with the conventional rolling bearing device for wheels, and prevents deformation of the bearing ring and occurrence of creep even when a large load is applied. It is an object of the present invention to provide a rolling bearing device for a wheel that can be prevented and that can prevent rotation failure and a decrease in life of the bearing device.

  In order to achieve the above object, a rolling bearing device for a wheel according to the present invention includes an outer ring member having a double row outer raceway surface formed on an inner periphery thereof, a coaxial arrangement with the outer ring member, and one of the outer ring members disposed on an outer periphery. The inner shaft on which the first inner raceway surface facing the outer raceway surface is formed, and chamfered portions are provided at both ends of the inner periphery, and a space between the two chamfered portions is configured as a fitting surface. Is fitted to the outer peripheral surface of the inner shaft in an interference fit state, and the outer ring is formed with a second inner raceway surface facing the other outer raceway surface of the outer ring member on the outer periphery. A rolling bearing device for a wheel comprising a rolling element interposed between a surface and first and second inner raceways, wherein the inner shaft has a solid portion corresponding to the fitting surface of the raceway The structure is characterized in that a portion other than the portion is a hollow structure.

  According to the rolling bearing device for a wheel having such a configuration, only the portion corresponding to the fitting surface of the raceway of the inner shaft has a solid structure, so that the necessary rigidity can be ensured for the portion. it can. As a result, the deformation of the race and the occurrence of creep when the wheel rolling bearing device is subjected to a large load can be prevented.

  In addition, since the portion other than the portion corresponding to the raceway fitting surface of the inner shaft has a hollow structure, by increasing the volume of the hollow structure portion as much as possible within a range in which rigidity can be secured, Compared to the bearing device, the weight can be reduced.

  According to the rolling bearing device for a wheel of the present invention, the weight of the bearing device can be reduced by the deformation of the raceway ring and the occurrence of creep even when a large load is applied while realizing a weight reduction as compared with the rolling bearing device for a wheel of the prior art. It is possible to prevent rotation failure and life reduction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a rolling bearing device for a wheel according to the present invention. This wheel rolling bearing device is arranged via an outer ring member 1 having outer race surfaces 1a and 1b having a circular arc cross section on the inner periphery, and a rolling element 2 made of steel balls on the inner periphery of the outer ring member 1. The inner shaft 4 and the race ring 3 are provided.

  The inner shaft 4 is disposed coaxially with the outer ring member 1, and a first inner raceway surface 4 a having a circular arc shape facing the one outer raceway surface 1 a of the outer ring member 1 is formed on the outer periphery. A wheel mounting flange 6 is formed on the outer periphery of one end of the inner shaft 4 (the vehicle outer side end portion on the left side in FIG. 1) so as to project radially outward. The flange 11 is formed so as to protrude in the radially outward direction. Further, a bolt 12 is provided for attaching a wheel side member (not shown) such as a wheel or brake rotor to the wheel mounting flange 6. An annular spigot portion 13 for fitting a brake rotor (not shown) is provided in the axial direction at the vehicle outer side end of the inner shaft 4.

  The bearing ring 3 has chamfered portions 3b at both ends of the inner periphery, and a space between the double-sided chamfered portions is configured as a fitting surface A. The fitting surface A is fitted into the outer peripheral surface of the small-diameter portion formed on the vehicle inner side (right side in FIG. 1) of the first inner raceway surface 4a of the inner shaft 4 in a tight-fitting state by press fitting. The ring 3 is fixed by caulking the end 8 of the inner shaft 4. In addition, a second inner raceway surface 3a having a circular arc shape facing the other outer raceway surface 1b of the outer ring member 1 is formed on the outer periphery.

  The rolling element 2 is interposed between the outer raceway surfaces 1a and 1b and the first inner raceway surface 4a and the second inner raceway surface 3a. A cage 10 is provided to hold the rolling elements 2 at a predetermined interval, and a seal 5 is provided to seal the annular space between the outer ring member 1 and the inner shaft 4. Further, a bottomed short cylindrical cover 14 produced by press-molding a metal plate such as iron is fitted into the inner peripheral surface of the end portion of the outer ring member 1.

  In the rolling bearing device for a wheel having the above-described configuration, the inner shaft 4 forms a solid structure portion 7 in a portion corresponding only to the fitting surface A of the bearing ring 3, and a hollow structure portion 9 other than the portion is formed. Yes. That is, both end faces 7a and 7b of the solid structure portion 7 are provided on a plane orthogonal to the axial direction passing through the boundary between the chamfered portion 3b and the fitting surface A, and also on the vehicle inner side of the solid structure portion 7. A hollow structure portion 9 is newly provided. The hollow structure 9 has a maximum volume within a range in which the rigidity of the inner shaft 4 can be secured, and the inner diameter of the inner shaft 4 increases as the vehicle inner side changes to the vehicle outer side. .

  As described above, it is possible to further reduce the weight of the inner shaft 4 by using the hollow structure portion 9 other than the solid structure portion 7 as compared with the conventional rolling bearing device for wheels. By forming the solid structure portion 7, even when a large load is applied to the wheel rolling bearing device, the rotation of the wheel rolling bearing device due to deformation of the raceway and the occurrence of creep and a decrease in the service life of the wheel rolling bearing device are caused. It is possible to ensure the necessary rigidity for preventing the above.

  In addition, the rolling bearing device for wheels of the present invention is not limited to the form shown in the drawings, and may be another form within the scope of the present invention. For example, in the above embodiment, the bearing portion is an angular ball bearing. However, it may be a tapered roller bearing device, and the rolling element 2 may be a tapered roller.

It is sectional drawing which shows one Embodiment of the rolling bearing device for wheels which concerns on this invention. It is sectional drawing of the conventional rolling bearing device for wheels.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring member 1a Outer raceway surface 2 Rolling element 3 Raceway 3a Second inner raceway surface 4 Inner shaft 4a First inner raceway surface 3b Chamfered portion 7 Solid structure portion 9 Hollow structure portion A Fitting surface

Claims (1)

An outer ring member having a double-row outer raceway surface formed on the inner periphery;
An inner shaft that is arranged coaxially with the outer ring member and has a first inner raceway surface that is opposed to one outer raceway surface of the outer ring member on the outer periphery;
There are chamfered portions at both ends of the inner periphery, and a space between the two-sided chamfered portions is formed as a fitting surface, and the fitting surface is fitted into the outer peripheral surface of the inner shaft in a tight-fitting state, and on the outer periphery. A bearing ring formed with a second inner raceway surface facing the other outer raceway surface of the outer ring member;
A wheel rolling bearing device comprising a rolling element interposed between the outer raceway surface and the first and second inner raceway surfaces,
A rolling bearing device for a wheel according to claim 1, wherein the inner shaft has a solid structure at a portion corresponding to the fitting surface of the raceway, and has a hollow structure other than the portion.

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