JP2006321337A - Anti-friction bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-friction bearing device for a wheel which surely maintains the fixation between a supporting member of a vehicle and the anti-friction bearing for the wheel even when a large moment load or a vibration is activated, and at the same time, which can cope with a weight reduction and a cost reduction as well. <P>SOLUTION: This anti-friction bearing device for the wheel is provided with a flange for attaching on at least one of the supporting members of an external member and an internal member. In the anti-friction bearing device for the wheel, a surface hardening treatment is applied to at least one of the supporting member and the flange for attaching. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheel rolling bearing device having a flange for attachment to a support member of a vehicle body on an outer member or an inner member.

  For example, a conventional wheel rolling bearing device will be described with reference to FIG.

  Rolling bearing device Huz for wheels shown in FIG. 4 includes an outer ring 1z, an inner ring 2z having a wheel mounting hub flange 2fz on the vehicle outer end side (right side in the figure), and a rolling element interposed between the outer and inner rings. It consists of 5z.

The inner periphery of the outer ring 1z has inner tracks 1a ₁ z and 1a ₂ z on the vehicle outer end side and the vehicle center side, respectively.

  An outer ring flange 1fz is provided on the outer peripheral portion of the outer ring 1z, and a predetermined number of screwed bolt holes 1jz for attaching a rolling bearing to the knuckle 8z as a support member are provided on the outer ring flange 1fz.

  The inner ring 2z includes a hub shaft Hbz formed integrally with a wheel flange 2fz for wheel mounting, and an inner ring element 3z fitted and fixed to a vehicle center side end portion (left side in the figure) of the hub shaft Hbz. It has become.

  Although the wheel rolling bearings for automobiles vary depending on the specifications of the vehicle, in the case of the wheel rolling bearing device shown in FIG. 4, the wheel rolling bearing device Huz is attached to the knuckle 8z as a supporting member, but other carriers, etc. It may be attached to the support member.

  The bearing mounting surface 81z of the supporting member such as the knuckle 8z may be machined, but even if it is machined, it may have a rough finish or remain painted. The finishing accuracy of the mounting surface is not as good as that of the bearing.

When perpendicularity of the rotational center line X ₀ -X ₀ of flatness and the rolling bearing of the mounting surface 1kz of the outer ring flange 1fz is good, the fastening force by a predetermined number of bolts 9z against the knuckle 8z and the outer ring flange 1fz and automobile A turning load or vibration force during operation is applied between the outer ring flange 1fz and the knuckle 8z and between the outer ring flange 1fz and the bolt 9z. 82z and the bearing surface 91z of the bolt 9z, the contact surface pressure generated on each surface becomes uniform.

However, when the flatness of the mounting surface 1 kz of the outer ring flange 1 fz and the perpendicularity to the rotation center line X ₀ -X ₀ are poor, or due to heat treatment of the outer ring 1 z or changes over time after processing of the outer ring flange 1 fz, the outer ring flange 1 fz. When the mounting surface 1kz is deformed, the contact surface between the mounting surface 1kz and the bearing mounting surface 81z of the knuckle 8z is locally contacted, and the contact surface pressure is locally excessive. There is a case.

  In such a case, if a large moment load during vibration or turning is repeatedly applied to a place where a high pressure is locally generated, the contact surface is worn or damaged.

  Furthermore, if this state is repeated, there is a risk that the fastening force of the outer ring flange 1fz and the knuckle 8z by the bolt 9z is loosened, and eventually the outer ring flange 1fz is cracked.

  In particular, considering the recent trend toward thinner outer ring flanges for weight reduction and lower cost, this is a more important problem.

There is a proposal as a wheel bearing device. (See Patent Document 1)
JP 2003-300401 A

  However, in Patent Document 1, a hardened uneven portion 5 is formed on the inner peripheral surface of the hub wheel 1, and the fitting portion 17b of the outer joint member 14 is expanded in diameter to bite the uneven portion. The outer ring flange of the outer ring is not engaged with the vehicle support member.

  The present invention has been made in view of the above points, and the present invention reliably maintains the fixation between the vehicle support member and the wheel roller bearing even when subjected to a large moment load or vibration, and is lightweight. An object of the present invention is to provide a rolling bearing device for a wheel that achieves reduction in cost and cost.

In order to achieve the above object, the present invention provides:
A first flange having a mounting surface to the support member of the vehicle body and a plurality of fastening holes formed in the mounting surface is provided on the outer peripheral portion, and an outer side having a double row inner peripheral track on the inner peripheral portion. Members,
An inner member having a double-row outer circumferential track opposed to the double-row inner circumferential track;
A rolling element interposed between the outer and inner members to enable relative rotation of the outer and inner members;
A rolling bearing device for a wheel, wherein the mounting surface of the first flange and the support member are brought into contact with each other, and the first flange and the support member are fastened by a bolt.
Provided is a wheel rolling bearing device in which at least one of a mounting surface of the first flange and a support member is subjected to surface hardening treatment.

The present invention also provides:
Furthermore, it is desirable that the rolling bearing device for a wheel is characterized in that at least one of the support member and the bearing surface of the bolt is subjected to a surface hardening treatment.

The present invention also provides:
Furthermore, it is desirable that the rolling bearing device for a wheel is characterized in that at least one of the first flange and the bearing surface of the bolt is subjected to surface hardening treatment.

The present invention also provides:
A first flange having a mounting surface to the wheel and a plurality of fastening holes drilled in the mounting surface on the outer peripheral portion; an outer member having a double row inner peripheral track on the inner peripheral portion;
A second flange having a mounting surface to the support member of the vehicle body and a plurality of fastening holes drilled in the mounting surface is provided at the end, and the outer periphery of the double row facing the inner peripheral track of the double row An inner member having a track;
A rolling element interposed between the outer and inner members to enable relative rotation of the outer and inner members;
A rolling bearing device for a wheel comprising:
Provided is a wheel rolling bearing device in which at least one of a mounting surface of a second flange and a support member is subjected to a surface hardening treatment.

The present invention also provides:
Furthermore, it is desirable that the rolling bearing device for a wheel is characterized in that at least one of the support member and the bearing surface of the bolt is subjected to a surface hardening treatment.

The present invention also provides:
Furthermore, it is desirable that the rolling bearing device for a wheel is characterized in that at least one of the second flange and the bearing surface of the bolt is subjected to surface hardening treatment.

The present invention also provides:
A rolling bearing device for a wheel is preferable in which the surface hardening treatment is a thin film treatment of diamond-like carbon.

The present invention also provides:
A rolling bearing device for a wheel, wherein the surface hardening treatment is a ceramic coating material treatment, is desirable.

  According to the present invention, even when a large moment load or vibration is applied, the fixing of the vehicle support member and the wheel rolling bearing is reliably maintained, and the wheel rolling bearing device achieves weight reduction and cost reduction. Can be provided.

  Embodiments according to the present invention will be described below with reference to the drawings.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIG.

FIG. 1 shows a cross-sectional view of this embodiment.
The wheel rolling bearing device Hu of the present embodiment is for a driving wheel, and includes a rolling bearing and a knuckle that is a part of a vehicle for mounting the rolling bearing.

The rolling bearing Hu ₀ has a first flange 1f on the outer periphery. The first flange 1f has a mounting surface 1k ₁ for mounting on a vehicle support member, which will be described later, and a bolt hole formed in a predetermined number on the mounting surface 1k _1. 1j ₁ has an outer ring 1, a wheel mounting flange 2f on the vehicle outer end side (right side in the figure), and integrally formed with this mounting flange 2f, and on the vehicle center side (left side in the figure). An inner ring 2 composed of an extending hub shaft Hb and an inner ring element 3 fitted and fixed to the end of the hub shaft Hb on the vehicle center side, and a plurality of intermediate wheels 2 interposed between the outer ring 1 and the inner ring 2. It consists of a row of balls 5.

The outer ring 1 is an outer member, has a first flange 1f for attachment having a predetermined thickness in the axial direction on the outer periphery, and has double-row inner tracks 1a ₁ and 1a ₂ on the inner periphery. ing.

The first flange 1f has a mounting surface 1k ₁ anti mounting surface 1k _2, bolt holes 1j ₁ given are threaded extends through the mounting surface 1k ₁ to counter mounting surface 1k ₂ number as a fastening hole It has been drilled. The mounting surface 1k _1, such as turning machined, perpendicularity is in good relative rotational center X ₁ -X ₁ of the rolling bearing. The opposite mounting surface 1k ₂ which is the surface opposite to the mounting surface 1k ₁ is a primary processing surface (forging surface if the primary processing is forging).

The inner ring 2 is an inward member, and has a second flange 2f for wheel attachment on the vehicle outer end side (right side in the figure). The inner ring 2 is formed integrally with the second flange 2f and extends toward the vehicle center. The hub shaft Hb and the inner ring element 3 fitted and fixed to the terminal portion on the vehicle center side of the hub shaft Hb. Double-row outer peripheral tracks 2a and 3a are provided on the outer periphery of the hub shaft Hb and the outer periphery of the inner ring element 3 so as to face the double-row inner peripheral tracks 1a ₁ and 1a ₂ .

The outer peripheral track 2a provided on the second flange 2f side (vehicle outer end side) of the hub axle Hb is provided integrally with the hub axle Hb. The inner ring 2 has a hollow shaft, and a serration 2s that is fitted to a drive shaft (not shown) is processed on the inner periphery. The wheel mounting flange 2f the wheel mounting bolts (not substantially) through hole 2f ₁ through which is provided a predetermined number in the circumferential direction.

A predetermined number of balls 5 and 5 are interposed between the inner peripheral tracks 1a ₁ and 1a ₂ and the outer peripheral tracks 2a and 3a, and cages 6 and 6 for holding the balls 5 and 5 are provided.

  Sealing seals 7 a and 7 b for sealing between the outer ring 1 and the inner ring 2 are provided at both ends of the outer ring 1.

The wheel rolling bearing device Hu is attached to the knuckle 8 which is a support member of the wheel rolling bearing Hu ₀ having the structure described above. Engaged Luo a mounting surface 1k ₁ and fastening bolt 9 the mounting surface 81 in contact with the knuckle 8 of the first flange 1f bearing Hu ₀ rolling wheel the bolt hole 1j ₁ from the back 82 of the first flange 1f of the knuckle 8 Yes. The knuckle 8 through hole 83 through which the bolts 9 are provided at positions corresponding to the bolt holes 1j _1.

In this case, keep the surface hardening treatment at least one of the mounting surface 81 of the mounting surface 1k ₁ and knuckle 8 of the outer ring 1. Thereby, even if the vehicle receives a biasing force or vibration during traveling, the mounting surface 81 of the mounting surface 1k ₁ and the knuckle 8 of the outer ring 1 which are in contact is not causing such wear, improved durability To do.

Furthermore, at least one of the surface to the back surface 82 and the knuckle 8 with the seating surface 91 of the bolt 9 for fastening to the mounting surface 1k ₁ of the first flange 1f does not cause deformation and wear undergoing vibration or moment load of the knuckle 8 It is desirable to perform a curing process.

  By performing such surface hardening, durability is maintained without increasing the thickness dimension of the first flange 1f of the outer ring 1, and it is possible to cope with weight reduction.

(Embodiment 2)
A second embodiment will be described with reference to FIG.

This embodiment is also a driving wheel, as compared to the first embodiment, when mounting the rolling bearing Hu ₀ knuckle 8, when the fastening of the outer ring 1 and the knuckle 8, anti-attachment of the opposite side of the mounting surface 1k ₁ from the surface 1k _2, is different from the first embodiment in that the combined fastening bolt 9 Luo.

In this embodiment, the through hole 1j ₂ is a predetermined number formed as fastening holes on the mounting surface 1k ₁ of the first flange 1f not threaded. On the other hand, bolt holes 84 are provided on the mounting surface 81 of the knuckle 8 is threaded in a position corresponding to the through hole 1j _2. Bolt 9 is screwed into the bolt hole 84 of the knuckle 8 through the through-hole 1j ₂ from the opposite mounting surface 1k ₂ side of the first flange 1f.

Mounting surface 81 of the mounting surface 1k ₁ and the knuckle 8 of the first flange 1f abuts also the seating surface 91 of the counter-mounting surface 1k ₂ and the bolt 9 of the first flange 1f is in contact. Is subjected to surface hardening treatment on at least one of the mounting surface 81 of the mounting surface 1k ₁ and knuckles 8 of the first flange 1f, but further, among the anti-mounting surface 1k ₂ bolt bearing surface 91 and the first flange 1f at least It is desirable to carry out surface hardening treatment on one side.
Since the configuration other than the above is the same as that of the first embodiment, the description of the reference numerals and configuration is omitted.

(Embodiment 3)
The third embodiment will be described with reference to FIG.

  The present embodiment is for a driven wheel, and the first and second embodiments are the outer member fixing and the inner member rotation, but this embodiment is the outer member rotating and the inner member fixing.

  That is, in the first embodiment and the second embodiment, the first flange 1f of the outer ring 1 that is the outer member is fixed to the knuckle 8, but in this embodiment, a wheel (not shown) is attached to the first flange 1. It is installed.

  In the first and second embodiments, a wheel (not shown) is attached to the second flange 2f of the inner ring 2 that is the inner member. In the present embodiment, the second flange 2f is fixed to the knuckle 8. is doing.

The outer ring 1 has a first flange 1f for wheel attachment on the outer periphery of the outer end side of the vehicle, and has double rows of inner tracks 1a ₁ and 1a ₂ on the inner periphery.

The inner ring 2 is attached to a knuckle 8 as a support member on the vehicle center side (right side in the figure), and extends from the second flange 2f toward the vehicle outer end side (left side in the figure) so as to be integrated. The inner ring element 3 has a hub shaft Hb formed and is fitted and fixed to the vehicle outer end side (left side in the figure) of the hub shaft Hb. Second flange 2f has a mounting surface 2k ₁ anti mounting surface 2k _2, bolt holes 2j ₂ given are threaded extends through the mounting surface 2k ₁ to counter mounting surface 2k ₂ number as a fastening hole A predetermined number is provided. Outer tracks 2a and 3a facing the inner tracks 1a ₁ and 1a ₂ of the outer ring 1 are formed on the outer periphery of the hub shaft Hb and the outer periphery of the inner ring element 3. The outer peripheral track 2a provided on the second flange 2f side (vehicle center side) of the hub axle Hb is provided integrally with the hub axle Hb. The inner ring element 3 is fixed by a hub shaft Hb and a nut N and a washer W that are combined with a threaded portion Sn processed at the vehicle outer end side end portion of the hub shaft Hb.

  Sealing seals 7 a and 7 b for sealing between the outer ring 1 and the inner ring 2 are provided at both ends of the outer ring 1. The sealing seal 7b is a lid-like seal fitted and fixed to the inner periphery of the outer ring 1 and seals the outer end side end.

The wheel rolling bearing Hu ₀ having the structure described above is attached to the knuckle 8 that is a support member to form a wheel rolling bearing device Hu. Engaged Luo the fastening bolt 9 the mounting surface 81 in contact with the mounting surface 2k ₁ and the knuckle 8 of the second flange 2f bearing Hu ₀ rolling wheel the bolt hole 2j ₁ from the back 82 of the second flange 2f of the knuckle 8 Yes. The knuckle 8 through hole 83 through which the bolts 9 are provided at positions corresponding to the bolt holes 2j _1.

In this case, the surface hardening treatment at least one of the mounting surface 81 of the mounting surfaces 2k ₁ and the supporting member 8 of the second flange 2f. Further, it is desirable that at least one of the bolt seat surface 91 and the back surface 82 of the support member 8 is subjected to a surface hardening process for the bolt seat surface 91 and the back surface 82 of the support member 8.

  In addition, about the structure shown in Embodiment 1, since it overlaps, description is abbreviate | omitted.

  As the surface treatment performed in the first, second, and third embodiments, there are carburizing treatment and carbonitriding treatment that are difficult to wear from the surface material surface, but a good effect is obtained by improving sliding resistance and wear resistance. Some of these means have been put into practical use in recent years.

  As a result, the wear resistance of the mounting surface is improved, the coefficient of friction on the mounting surface is sufficiently reduced, and the occurrence of scratches and wear is prevented.

  Specifically, diamond-like carbon (DLC) thin film agent coating and ceramic-based coating agent coating such as Ti alloy are practically or practically used as surface hardening treatment means.

  The outline of the diamond-like carbon (DLC) thin film coating and the ceramic coating coating including Ti alloy is as follows.

Typical surface hardening treatments that have been improved in recent years include TiN, TiCN, TiAlN, TiC, CrN, multilayer coating films TiC / TiN, TiC / TiCN / Al ₂ O ₃ , TiC / Al ₂ O ₃ / TiN, TiC / Examples thereof include ceramic coating agents such as TiCN / TiC / Al ₂ O ₃ and diamond-like carbon (DLC) coating. In addition to these coatings, surface treatment such as nitrosulfiding is also effective. These surface hardening treatments increase the hardness of the surface and increase the wear resistance and corrosion resistance.

Ti alloy-based coating films such as TiN, TiAlN, TiCN, or multilayer coating films based on these alloys have high altitude, low friction, and strong adhesion, and are less susceptible to wear and scratches. is there. Among these, TiN and TiC / TiN multilayer coating films are excellent in preventing wear and peeling. In addition, a foot coat film such as TiC / TiCN / AL ₂ O ₃ , TiC / Al ₂ O ₃ / TiN, TiC / TiCN / TiC / Al ₂ O ₃ is excellent in improving friction resistance and preventing adhesion. .

  As specific examples of performance values, in terms of hardness, the TiN film is 2000-2400 (HV), the TiAlN film is 2300-2800 (HV), the TiCN film is 3000-3500 (HV), and the friction coefficient is the TiN film. 0.4-0.45, TiCN film 0.12-0.15, and the performance varies depending on the type of Ti alloy.

  The coating film by the diamond carbon (DLC) thin film agent has higher wear resistance than the Ti alloy, and the temperature of the coating process is usually 200 ° C. or lower, which is lower than the coating process temperature of the Ti alloy or the like. For this reason, characteristics such as hardness obtained by quenching and tempering of martensitic stainless steel and high-speed steel usually used for bearings have the advantage that they are not changed by the thermal influence during the coating process. As a result, the bearing shape and bearing clearance conforming to the design, and the corresponding bearing performance characteristics are maintained.

  Further, the fact that it can be applied to martensitic stainless steel and high-speed steel is also an advantage in application to bearing members. Recently, DLC with improved adhesion has been developed, and its application to a rotating part and a sliding part in a high speed and high load range is being put into practical use.

  In the first, second, and third embodiments described above, the inner member has a configuration in which the outer peripheral track 2a on the second flange 2f side is provided integrally with the hub shaft Hb, but the inner ring element 3 in each embodiment. A separate inner ring element similar to that shown in FIG. 5 may be fitted and fixed to the hub axle Hb in parallel with the inner ring element 3.

The outer member directly forms the inner tracks 1a ₁ and 1a ₂ on the inner periphery of the outer ring 1, but a configuration in which a separate outer ring is fitted to the inner side of the outer member having the first flange 1f. As well.

In addition, the rolling element is not limited to a ball, and is also implemented in a tapered roller.
Further, although the knuckle has been described as the support member, the support member is not limited to the knuckle, but is intended for a vehicle-side mounting portion such as a carrier.

FIG. 1 is a sectional view showing Embodiment 1 of the present invention. FIG. 2 is a sectional view showing Embodiment 2 of the present invention. FIG. 3 is a sectional view showing Embodiment 3 of the present invention. FIG. 4 is a sectional view showing a conventional example.

Explanation of symbols

Hu: Rolling bearing device for wheels Hu ₀ : Rolling bearing 1: Outer member 1a ₁ , 1a ₂ : Inner circumferential track 1f: First flange 1j ₁ : Bolt hole 1k ₁ : Mounting surface 1k ₂ : Anti-mounting surface 2: Inside Side member 2a: outer peripheral track 2f: second flange 3: inner ring element 3a: outer peripheral track Hb: hub shaft 5: ball 6: cage 7a, 7b: sealing seal 8: support member 81: mounting surface 82: back surface 9: fastening Bolt 91: Bolt bearing surface

Claims (8)

A first flange having a mounting surface to the support member of the vehicle body and a plurality of fastening holes formed in the mounting surface is provided on the outer peripheral portion, and an outer side having a double row inner peripheral track on the inner peripheral portion. Members,
An inner member having a double-row outer circumferential track opposed to the double-row inner circumferential track;
A rolling element interposed between the outer and inner members to enable relative rotation of the outer and inner members;
A rolling bearing device for a wheel, wherein the mounting surface of the first flange and the support member are brought into contact with each other, and the first flange and the support member are fastened by a bolt.
A rolling bearing device for a wheel, wherein at least one of the mounting surface of the first flange and the support member is subjected to surface hardening treatment.   Further, at least one of the support member and the bearing surface of the bolt is subjected to a surface hardening treatment.   Further, at least one of the first flange and the bearing surface of the bolt is subjected to a surface hardening treatment, and the rolling bearing device for a wheel according to claim 1, wherein: A first flange having a mounting surface to the wheel and a plurality of fastening holes drilled in the mounting surface on the outer peripheral portion; an outer member having a double row inner peripheral track on the inner peripheral portion;
A second flange having a mounting surface to the support member of the vehicle body and a plurality of fastening holes drilled in the mounting surface is provided at the end, and the outer periphery of the double row facing the inner peripheral track of the double row An inner member having a track;
A rolling element interposed between the outer and inner members to enable relative rotation of the outer and inner members;
A rolling bearing device for a wheel, wherein the mounting surface of the second flange and the support member are brought into contact with each other, and the second flange and the support member are fastened by a bolt.
A rolling bearing device for a wheel, wherein at least one of the mounting surface of the second flange and the support member is subjected to a surface hardening treatment.   Further, at least one of the support member and the seating surface of the bolt is subjected to a surface hardening treatment.   Further, at least one of the second flange and the bearing surface of the bolt is subjected to a surface hardening treatment, and the wheel rolling bearing device according to claim 4.   The wheel rolling bearing device according to any one of claims 1 to 6, wherein the surface hardening treatment is a thin film treatment of diamond-like carbon.   The wheel rolling bearing device according to any one of claims 1 to 6, wherein the surface hardening treatment is a ceramic coating material treatment.

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