JP2008175276A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device with greatly reduced cost by reducing the number of components and standardizing a bearing while elongating the life of the bearing. <P>SOLUTION: The wheel bearing device comprises a hub drum 1 which has an integrated wheel mounting flange 6 at one end of a cylindrical base portion 5 and on which a cylindrical brake drum 8 is continuously provided extending from the outer end of the wheel mounting flange 6 to the axial direction, a spindle 4 which has an integrated vehicle body mounting flange 9 at the other end and which is formed with a shaft portion 10 extending from the vehicle body mounting flange 9 to the axial direction and a small diameter stepped portion 13 at the end of the shaft portion 10, and the wheel bearing for supporting a wheel rotatably relative to the spindle 4. The wheel bearing consists of deep groove ball bearings 2, 3 formed of a pair of standard line products. The deep groove ball bearings 2, 3 are each pressed into the base portion 5 via a predetermined interference and set at a negative clearance. The pair of deep groove ball bearings 2, 3 is filled with grease different in property. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like, and more particularly to a wheel bearing device that achieves significant cost reduction by reducing the number of parts and standardizing a bearing along with extending the life of the bearing It is.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. In this double row angular contact ball bearing, a plurality of balls are interposed between a fixed ring and a rotating ring, and a predetermined contact angle is given to the balls so as to contact the fixed ring and the rotating ring. As such a conventional wheel bearing device, one shown in FIG. 4 is known. In the following description, the side closer to the outer side of the vehicle in a state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  The wheel bearing device 50 mainly includes a hub drum 51, a double-row angular ball bearing 60, and a spindle 70. The hub drum 51 integrally has a wheel mounting flange 53 for attaching a wheel (not shown) to one end of a cylindrical base 52, and the wheel is fixed to a circumferentially equidistant position of the wheel mounting flange 53. A hub bolt 54 is installed. A brake drum 55 is connected to the wheel mounting flange 53, and a shoe surface 55a is formed on the inner periphery thereof.

  A double-row angular ball bearing 60 is fitted to the inner peripheral portion of the base portion 52 of the hub drum 51, and the wheel is rotatably supported with respect to the spindle 70. The spindle 70 is integrally formed with a vehicle body mounting flange 72 for mounting to the vehicle body 71. A flange 56 is integrally formed on the inner periphery of the outer end of the base 52, and a retaining ring 57 is mounted on the inner periphery of the inner end, and the double row angular ball bearing 60 is formed by the retaining ring 57 and the flange 56. Is fixed in the axial direction.

  The double row angular contact ball bearing 60 includes an outer ring 61 having double row outer raceway surfaces 61a and 61a formed on the inner circumference, and an inner raceway surface 62a facing the double row outer raceway surfaces 61a and 61a on the outer circumference. Are formed of a pair of inner rings 62, 62, double-row balls 63, 63 accommodated between the rolling surfaces, and a holder 64 for holding the balls 63 in a freely rolling manner.

  The inner peripheral surface of the flange 56 is formed so as to face the outer peripheral surface of the inner ring 62 on the outer side through a slight radial clearance, and leakage of the lubricating grease enclosed in the bearing and the bearing from the outside It constitutes a labyrinth seal that prevents rainwater and dust from entering inside.

  Here, the spindle 70 is provided with a small-diameter stepped portion 74 extending in the axial direction from the shoulder 73, and the double-row angular ball bearing 60 is press-fitted into the outer peripheral surface thereof. A threaded portion 75 is formed at the end of the spindle 70, and a pair of inner rings 62, 62 are sandwiched between the nut 76 fastened to the threaded portion 75 and the shoulder portion 73, and the double-row angular contact. A ball bearing 60 is positioned and fixed in the axial direction.

An end cap 58 is attached to the wheel pilot portion 53a of the hub drum 51 to prevent muddy water from entering from the outside. On the other hand, a seal 59 is attached to the inner periphery of the end of the base 52, and a radial lip 59a formed in a bifurcated shape is in sliding contact with the outer peripheral surface of the inner ring 62 on the inner side. The seal 59 prevents leakage of the lubricating grease sealed inside the bearing and prevents rainwater, dust, etc. from entering the bearing from the outside. This eliminates the need for assembly consisting of strict process control, has high sealing performance, and can be lightweight and compact.
JP 2003-21151 A

  In such a conventional wheel bearing device 50, when the spindle 70 is inserted at the time of assembly into a vehicle, there is no possibility that the radial lip 59a is reversed and the seal 59 is damaged. However, on the other hand, bearing manufacturers still need strict process control not only in the assembly process of the seal 59 but also in the clearance adjustment of the double row angular contact ball bearing 60 and the processing process of each part. There is a limit to the cost reduction of the product because it uses a double row angular contact ball bearing.

  SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has an object to provide a bearing device for a wheel that achieves significant cost reduction by reducing the number of parts and standardizing the bearing as well as extending the life of the bearing. Yes.

  In order to achieve such an object, the invention according to claim 1 of the present invention integrates a rotating side member integrally having a wheel mounting flange for mounting a wheel at one end and a vehicle body mounting flange for mounting to a vehicle body. And a wheel bearing device that rotatably supports the wheel with respect to the fixed side member, wherein the wheel bearing comprises a pair of deep groove ball bearings. Seals are attached to both ends of the deep groove ball bearing, and grease having different properties are sealed in the pair of deep groove ball bearings.

  Thus, in the wheel bearing device that rotatably supports the wheel via the wheel bearing, the wheel bearing is composed of a pair of deep groove ball bearings, and seals are attached to both ends of these deep groove ball bearings. Since a pair of deep groove ball bearings are filled with greases having different properties, a bearing device for a wheel is provided which achieves a significantly lower cost by extending the life of the bearing, reducing the number of parts, and standardizing the bearing. Can do.

  Preferably, if the pair of deep groove ball bearings is composed of a standard series product as in the invention described in claim 2, the cost can be significantly reduced by standardizing the bearings.

  Further, as in the third aspect of the present invention, if the pair of deep groove ball bearings is press-fitted into at least the rotating side member through a predetermined shimoshiro and set to a negative clearance, creep occurs. As well as preventing backlash after assembly, the bearing rigidity can be increased, and the life and running stability of the vehicle can be improved.

  According to a fourth aspect of the present invention, the grease enclosed in the inner deep groove ball bearing of the pair of deep groove ball bearings includes a mineral oil-based base oil and a urea-based thickener, The grease encapsulated in the deep groove ball bearing on the side is made of mineral oil and synthetic oil and contains a urea-based thickener, which prevents fretting during transportation and assembly. The durability of the bearing can be improved correspondingly.

  If the grease containing the extreme pressure additive is sealed in the deep groove ball bearing having a higher surface pressure among the pair of deep groove ball bearings as in the invention according to claim 5, one layer of the bearing Long life can be achieved.

  A wheel bearing device according to the present invention includes a rotating side member integrally including a wheel mounting flange for mounting a wheel at one end, a fixed side member integrally including a vehicle body mounting flange for mounting to a vehicle body, In a wheel bearing device comprising a wheel bearing for rotatably supporting the wheel with respect to a side member, the wheel bearing comprises a pair of deep groove ball bearings, and seals are provided at both ends of these deep groove ball bearings. As well as being mounted, greases with different properties are sealed in the pair of deep groove ball bearings, so the bearings for wheels are designed to extend the life of the bearings, reduce the number of parts and standardize the bearings, thereby significantly reducing costs. An apparatus can be provided.

  A hub drum integrally having a wheel mounting flange for mounting a wheel at one end of a cylindrical base, and a cylindrical brake drum extending in an axial direction from the outer end of the wheel mounting flange, and the other end A vehicle body mounting flange for being attached to the vehicle body is integrally formed at the portion, and a shaft portion extending in the axial direction from the vehicle body mounting flange and a small diameter step portion extending further in the axial direction from the shaft portion via the shoulder portion are formed. A wheel bearing device including a spindle and a wheel bearing for rotatably supporting the wheel with respect to the spindle, wherein the wheel bearing is constituted by a pair of standard grooved deep groove ball bearings, Each of the deep groove ball bearings is press-fitted into the base through a predetermined squeeze to set a negative clearance, and grease having different properties is applied to the pair of deep groove ball bearings. It is sealed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is a longitudinal sectional view showing a deep groove ball bearing on the inner side of FIG. 1, and FIG. It is a longitudinal cross-sectional view which shows the outer side deep groove ball bearing same as the above.

  This wheel bearing device is for a driven wheel, and has a hub drum 1, a pair of deep groove ball bearings 2, 3 and a spindle 4 as main components. The hub drum 1 is made of gray cast iron such as FC25 or spheroidal graphite cast iron such as FCD45, and integrally has a wheel mounting flange 6 for mounting a wheel (not shown) on one end of a cylindrical base portion 5. Hub bolts 7 for fixing the wheels at the circumferentially equidistant positions of the flange 6 are implanted. Further, a cylindrical brake drum 8 extending in the axial direction from the outer end portion of the wheel mounting flange 6 is continuously provided, and a shoe surface 8a is formed on the inner periphery thereof. A pair of deep groove ball bearings 2 and 3 are fitted to the inner peripheral portion of the base portion 5 of the hub drum 1, and a wheel is rotatably supported with respect to the spindle 4.

  The spindle 4 integrally has a vehicle body mounting flange 9 for mounting to a vehicle body (not shown), and a shaft portion 10 extending from the vehicle body mounting flange 9 in the axial direction is projected. Shoulder portions 11 and 12 are formed at both ends of the shaft portion 10, and a small-diameter step portion 13 further extending in the axial direction from the outer-side shoulder portion 12, and a male screw 14 is formed at the end portion of the small-diameter step portion 13. Has been.

  The spindle 4 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S45C, and the surface hardness is 50 to 64 HRC by induction hardening from the shoulder portion 11 to the shaft portion 10 and the small diameter step portion 13. It has been cured to the extent of. Thereby, it has sufficient mechanical strength with respect to the bending load applied to the axial part 10 grade | etc., And the fretting resistance of the fitting part of the deep groove ball bearings 2 and 3 improves.

  On the inner periphery of the base portion 5 of the hub drum 1, fitting portions 15 and 16 to which a pair of deep groove ball bearings 2 and 3 are fitted, and a cylindrical shoulder portion 17 is formed between the fitting portions 15 and 16. Yes. Of the pair of deep groove ball bearings 2 and 3, the inner deep groove ball bearing 2 is fitted into the shaft portion 10 of the spindle 4 and the fitting portion 15 of the base portion 5 and is sandwiched between the shoulder portions 11 and 17. It is positioned in the state. On the other hand, the outer side deep groove ball bearing 3 is press-fitted into the small-diameter step portion 13 of the spindle 4 and the fitting portion 16 of the base portion 5 with a predetermined shimiro while being in contact with both shoulder portions 12 and 17. The deep groove ball bearing 3 is fixed in the axial direction by a fixing nut 19 screwed onto the male screw 14 via a washer 18.

  An end cap 20 is attached to the outer end opening of the hub drum 1 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater, dust and the like into the bearing from the outside. The end cap 20 is formed into a cup shape by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). ing.

  Further, the end cap 20 is formed with a cylindrical portion 20a that is press-fitted into the hub drum 1 so as to protrude further from the side surface of the wheel mounting flange 6 to the outer side, and constitutes a pilot portion that supports the wheel. As a result, the shape of the hub drum 1 can be simplified, and the number of processing steps such as forging, casting, and turning can be reduced, and the cost can be reduced.

  In this embodiment, the deep groove ball bearing 2 on the inner side is formed of a so-called standard series product composed of 62, 63, etc. defined in JIS B1513 “Nominal number of rolling bearing”, and is shown in FIG. Thus, an outer ring 21 having an arcuate outer rolling surface 21a formed on the inner periphery, an inner ring 22 having an arcuate inner rolling surface 22a facing the outer rolling surface 21a on the outer periphery, A plurality of balls 24 are provided between the running surfaces 21 a and 22 a so as to be freely rollable via a cage 23. And the seal | stickers 25 and 25 are mounted | worn with the both ends.

  The outer ring 21, the inner ring 22 and the ball 24 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching. The cage 23 is a so-called corrugated cage in which two annular holding plates 23a and 23a are fixed by rivets 23b, which are formed by cold working from a cold rolled steel plate (JIS standard SPCC system or the like). .

  The outer side deep groove ball bearing 3 is made of standard series products such as 62 and 63, and is smaller than the inner side deep groove ball bearing 2. And as shown in FIG.2 (b), the outer ring | wheel 26 in which the arc-shaped outer side rolling surface 26a was formed in the inner periphery, and the arc-shaped inner side rolling surface 27a which opposes the outer side rolling surface 26a in the outer periphery. The formed inner ring 27 and a plurality of balls 29 accommodated between the rolling surfaces 26a and 27a via a cage 28 so as to roll freely. And the seal | stickers 30 and 30 are mounted | worn with the both ends.

  The outer ring 26, the inner ring 27 and the ball 29 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching. The cage 28 is formed of a cold rolled steel plate (JIS standard SPCC system or the like) by press working, and includes a corrugated cage in which two annular holding plates 28a and 28a are fixed by rivets 28b.

  In the present embodiment, the internal clearance of the pair of deep groove ball bearings 2 and 3 is set to a predetermined positive clearance before assembly, but after assembly, the fitting portion of the base 5 is set to a predetermined negative clearance. 15 and 16 are press-fitted through a predetermined scissors. As a result, it is possible to prevent the occurrence of creep and prevent rattling after assembly to increase the bearing rigidity, thereby improving the service life and running stability of the vehicle. Note that the shimoshiro may be provided not only between the fitting portions 15 and 16 of the base portion 5 but also between the spindle 4. The term “creep” as used herein refers to a phenomenon caused by shortage of the fitting portion or inaccuracy of the fitting portion. The creep may cause the fitting surface to become a mirror surface or a cloudy surface, which may be galling.

  Further, since the pair of deep groove ball bearings 2 and 3 can be positioned only by the shoulder portions 17, 11 and 12, there is no need for a retaining ring or a spacer as in the prior art, and the cost is greatly reduced by reducing the number of parts and standardizing the bearing It is possible to provide a wheel bearing device that achieves the above.

  Here, in the present embodiment, the pair of deep groove ball bearings 2 and 3 is constituted by a sealed type bearing having seals 25 and 30 attached to both ends, and greases having different properties are provided to the deep groove ball bearings 2 and 3. It is enclosed. That is, the deep groove ball bearing 2 on the inner side has good fretting resistance and excellent rust prevention performance. Specifically, the base oil is a mineral oil type, the thickener is a non-soap type such as urea, For example, Pyroc Universal N6C (trade name; manufactured by Mitsubishi Nisseki) containing a sulfonate anticorrosive and a phenolic antioxidant as additives is enclosed. Further, the outer side deep groove ball bearing 3 has grease having good fretting resistance and high temperature durability, specifically, synthetic oils such as mineral oils + synthetic hydrocarbon oils, For example, Rare Max 9B367 (commercial surface; manufactured by Kyodo Yushi Co., Ltd.) containing a non-soap type such as urea and a sulfonate type rust preventive agent and a phenol type antioxidant as additives is enclosed. Here, fretting is a phenomenon in which when a vibration load is applied to the contact portion or the swinging portion swings with a small amplitude, the lubricant is pushed out from the portion, resulting in no lubrication and significant wear. In the case of a rolling surface, it becomes a depression of the rolling element pitch and is also called Brinell indentation.

  In this way, the appropriate grease for each deep groove ball bearing 2, 3, that is, the inner deep groove ball bearing 2 exposed to the external environment and used under wet conditions, and heat transfer from the brake friction surface, The outer-side deep groove ball bearing 3 used in the atmosphere is filled with grease corresponding to each use condition, so that fretting during transportation and assembly can be prevented and the durability of the bearing can be improved. it can.

  Furthermore, a solid lubricant made of sulfur, phosphorus, molybdenum disulfide, or the like, or an organic metal compound, a so-called extreme pressure additive, is added to a bearing having a high surface pressure, for example, a deep groove ball bearing 3 on the outer side having a small size. By enclosing the grease containing, the life of the bearing can be further extended. That is, it is possible to select an appropriate grease depending on the structure including peripheral parts, conditions for incorporation in the vehicle, vehicle specifications, and the like.

  FIG. 3 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention. Note that the same parts and parts as those in the first embodiment described above or parts and parts having the same functions are denoted by the same reference numerals and detailed description thereof is omitted.

  This wheel bearing device is for a drive wheel, and mainly includes a hub wheel 31, an outer member 32, and a pair of deep groove ball bearings 2 and 33. The hub wheel 31 integrally has a wheel mounting flange 34 at one end, a small-diameter step portion 31b extending in the axial direction from the wheel mounting flange 34 via a shoulder 31a is formed on the outer periphery, and a torque transmission is formed on the inner periphery. Serrations (or splines) 31c are formed. The hub ring 31 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the surface hardness is set to a range of 58 to 64 HRC by induction hardening from the shoulder portion 31a to the small diameter step portion 31b. A curing process is applied.

  The outer member 32 integrally has a vehicle body mounting flange 32b for mounting to the vehicle body (not shown) on the outer periphery, and fitting portions 32a, 32a into which the pair of deep groove ball bearings 2, 33 are press-fitted on the inner periphery. And the shoulder part 17 is formed between these fitting parts 32a and 32a. This outer member 32 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the fitting portions 32a and 32a are hardened by induction hardening to a surface hardness of 58 to 64 HRC. ing.

  Of the pair of deep groove ball bearings 2 and 33, the inner deep groove ball bearing 2 is fitted into the small diameter step portion 31 b of the hub wheel 31 and the fitting portion 32 a of the outer member 32. On the other hand, the outer side deep groove ball bearing 33 is made of standard series products of the same size, such as 62 and 63, like the inner side deep groove ball bearing 2, and is fitted to the small diameter step portion 31b and the fitting portion 32a. Positioning is performed while being sandwiched between the portions 31 a and 17. An inner ring spacer 35 is interposed between the pair of deep groove ball bearings 2 and 33.

  A seal 36 is attached to the outer end of the outer member 32, and the leakage of the lubricating grease sealed inside the bearing by sliding on the shoulder 31a having an outer periphery formed into an arcuate surface, and from the outside to the inside of the bearing. Prevents intrusion of rainwater and dust.

  In the present embodiment, the pair of deep groove ball bearings 2 and 33 are made of standard series products of the same size. Like the above-described embodiment, the pair of deep groove ball bearings 2 and 33 is set to a predetermined positive clearance before assembly, but serves as a rotation side member. The hub wheel 31 is press-fitted into the small-diameter step portion 31b of the hub wheel 31 through a predetermined squeeze, and the internal clearance after assembly is set to a predetermined negative clearance. As a result, the cost can be significantly reduced, the occurrence of creep and play after assembly can be prevented, the bearing rigidity can be increased, and the life and running stability of the vehicle can be improved.

  Here, the pair of deep groove ball bearings 2 and 33 are formed of sealed type bearings, and greases having different properties are sealed in the deep groove ball bearings 2 and 33. That is, the inner deep groove ball bearing 2 is filled with grease having good fretting resistance and excellent rust prevention performance, and the outer deep groove ball bearing 33 has good fretting resistance. The grease is packed with high temperature durability. As described above, in this embodiment, since each of the deep groove ball bearings 2 and 33 is filled with appropriate grease corresponding to the use conditions, the fretting during transportation and assembly is prevented, thereby improving the durability of the bearing. Can be improved.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to a wheel bearing device using a pair of deep groove ball bearings regardless of a driven wheel or a drive wheel.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. (A) is a longitudinal cross-sectional view which shows the deep groove ball bearing of the inner side of FIG. (B) is a longitudinal sectional view showing the deep groove ball bearing on the outer side of the same. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

1 ... hub drums 2, 3, 33 ... deep groove ball bearings 4 ... spindle 5 ············· Base 6, 34 ·········· Wheel mounting flange 7 ························ Hub bolt ... Brake drum 8a ... Shoe surface 9, 32b ... Car body mounting flange 10 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shafts 11, 12, 17, 31a ・ ・ ・ Shoulders 13, 31b ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 14 ・ ・ ・ ・ ・ ・ ・ ・..... Male thread 15, 16, 32a ... Fitting part 18 ... Washer 19 ... Fixing nut 20 ... End cap 20a ····························································································· .... Inner rings 22a, 27a ... Inner rolling surfaces 23, 28 ... ... Retainers 23a, 28a ... ... Annular Retaining plate 23b, 28b ... Rivet 24, 29 ... Ball 25, 30 ... Seal 31 ...・ ・ ・ ・ ・ ・ Hub wheel 31c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Serration 32 ・ ・ ・ ・ ・ ・ ・ ・ Outer member 35 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ Inner ring spacer 50 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bearing bearing device 51 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub drum 52 ・ ・ ・ ・ ・ ・ ・ ・... Base 53 ... ... Wheel mounting flange 53a ... Wheel pilot part 54 ... Hub bolt 55 ... · Brake drum 55a ··········· Shoe surface 56 ············································ ... End cap 59 ... Seal 59a ... Radial lip 60 ... .... Double row angular contact ball bearing 61 ... Outer ring 61a ... Outer rolling surface 62 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 62a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 63 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ball 64 ・ ・ ・ ・ ・ ・.... Retainer 70 ...・ ・ ・ ・ ・ ・ ・ ・ Spindle 71 ・ ・ ・ ・ ・ ・ ・ ・ Car body 72 ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 73 ・ ・ ・ ・ ・ ・ ・ ・...... Shoulder 74 ......... Small diameter step 75 ......... Screw 76 ... ····nut

Claims (5)

A rotation side member integrally having a wheel mounting flange for mounting a wheel on one end;
A fixed-side member integrally having a vehicle body mounting flange for mounting to the vehicle body;
In a wheel bearing device comprising a wheel bearing for rotatably supporting the wheel with respect to the fixed side member,
The wheel bearing is composed of a pair of deep groove ball bearings, seals are attached to both ends of the deep groove ball bearings, and grease having different properties is sealed in the pair of deep groove ball bearings, respectively. Wheel bearing device.   The wheel bearing device according to claim 1, wherein the pair of deep groove ball bearings is formed of a standard series product.   3. The wheel bearing device according to claim 1, wherein the pair of deep groove ball bearings are press-fitted into at least the rotating side member via a predetermined squeeze and set to a negative clearance. 4.   Of the pair of deep groove ball bearings, the grease sealed in the inner deep groove ball bearing includes a mineral base oil and a urea-based thickener, and a grease sealed in the outer deep groove ball bearing. The wheel bearing device according to any one of claims 1 to 3, wherein the base oil is a mineral oil type and a synthetic oil type, and a urea type thickener is contained.   The wheel bearing device according to any one of claims 1 to 4, wherein grease containing an extreme pressure additive is enclosed in a deep groove ball bearing having a higher surface pressure among the pair of deep groove ball bearings.

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