JP6157280B2 - Wheel bearing device - Google Patents

Description

  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 secures a bearing life by preventing a change in bearing clearance while reducing weight.

  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.

  Further, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. It is roughly classified into a second generation structure in which a body mounting flange or a wheel mounting flange is directly formed on the outer periphery of the member, or a third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel. .

  In recent years, in such wheel bearing devices, not only improvement in durability and cost reduction, but also weight reduction has been progressing in order to improve fuel efficiency. For example, the wheel bearing device 51 shown in FIG. 11 includes an inner member 52, an outer member 53, and double-row balls 54. The inner member 52 includes a hub ring 55 and an inner ring 56 fixed to the hub ring 55. The hub wheel 55 has a wheel mounting flange 55a, an inner rolling surface 55b, and a small-diameter step portion 55c formed on the outer periphery. The inner ring 55 has an inner rolling surface 55a formed on the outer periphery, and is press-fitted and fixed to the small diameter step portion 52c of the hub ring 55.

  The outer member 53 is disposed outside the inner member 52 and includes an attachment member 57 and an outer ring 58 as shown in FIG. The attachment member 57 is formed in a substantially cylindrical shape, and is formed of a material having a specific gravity lower than that of steel, such as an aluminum alloy or a magnesium alloy. Thereby, the outer member 53 can be reduced in weight.

  A vehicle body attachment flange 59 is formed on the outer peripheral surface of the attachment member 57. The vehicle body attachment flange 59 has a base portion 59a and a knuckle attachment portion 59b. A plurality of knuckle attachment portions 59b are formed at equal intervals on the outer peripheral surface of the base portion 59a, and a vehicle suspension device (knuckle) (not shown) is attached to the knuckle attachment portion 59b.

  The outer ring 58 is disposed on the inner side of the mounting member 57 in a state where the outer peripheral surface is in contact with the inner peripheral surface of the mounting member 57. The outer ring 58 is hardened by ordinary quenching using bearing steel used for general-purpose bearings as a material. And the hardness of the outer ring | wheel 58 is selected as 650Hv (Vickers hardness) or more as hardness required for a rolling fatigue life.

  The outer ring 58 has double row outer rolling surfaces 58a, 58a formed on the inner periphery, and the minimum thickness W (hereinafter referred to as the minimum thickness W) in the portion where the outer rolling surfaces 58a are formed is: It is selected to be 10% or more and 40% or less of the diameter of the ball 54. Preferably, the minimum thickness W is selected to be 20% or more and 30% or less of the diameter of the ball 54. Thereby, it is possible to ensure an appropriate rolling fatigue life while reducing the weight of the outer ring 58.

  A female screw hole 61 is formed at a substantially central position in the axial direction of the thick part 58 b of the outer ring 58 in a state where the mounting member 57 and the outer ring 58 are combined with each other and the insertion hole 60. A fixing member 62 made of a bolt is fastened to the female screw hole 61. Thereby, it is possible to suppress the occurrence of a creep phenomenon between the attachment member 57 and the outer ring 58 (see, for example, Patent Document 1).

JP2011-149478A

  This conventional wheel bearing device 51 has a feature that the bearing life and the creep resistance can be ensured while reducing the weight. However, if the bearing temperature rises while the vehicle is running, the bearing clearance changes due to the difference in linear expansion coefficient due to the difference in material between the mounting member 57 and the outer ring 58 in the outer member 53, and the bearing preload during assembly is changed. There is a possibility that problems such as so-called preload loss that cannot be maintained occur.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing device in which a bearing life is ensured by preventing a change in bearing clearance while reducing weight.

  In order to achieve the object, the invention according to claim 1 of the present invention has a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and an outer side in which a double row outer rolling surface is formed on the inner periphery. A hub ring having a member and a wheel mounting flange for mounting a wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and press-fitting the small-diameter step portion of this hub ring through a shimoshiro An inner member formed of at least one inner ring formed on the outer periphery and formed with a double-row inner rolling surface opposite to the double-row outer rolling surface, and both rolling of the inner member and the outer member. In the wheel bearing device including a double row rolling element that is rotatably accommodated between the running surfaces via a cage, the outer member integrally includes the vehicle body mounting flange on the outer periphery, An annular mounting member having a cylindrical fitting surface formed on the periphery, and the mounting member A steel outer ring fixed to the fitting surface and integrally formed with the outer circumferential rolling surface of the double row on the inner periphery, and the mounting member is made of a material having a specific gravity lower than that of steel. An annular expansion suppression member is press-fitted into the outer peripheral surface, and the expansion suppression member is formed of a material having a smaller linear expansion coefficient than the mounting member.

  In this way, in the wheel bearing device of the first to third generation structures, the outer member has an annular mounting in which the body mounting flange is integrally formed on the outer periphery and the cylindrical fitting surface is formed on the inner periphery. A member and a steel outer ring fixed to the fitting surface of the mounting member and integrally formed with a double row outer rolling surface on the inner periphery, and the mounting member is made of a material having a lower specific gravity than steel. Since an annular expansion suppression member is press-fitted into the outer peripheral surface of the mounting member, and the expansion suppression member is formed of a material having a smaller linear expansion coefficient than the mounting member, the bearing temperature has increased during traveling of the vehicle. Even in this case, the difference in linear expansion coefficient due to the difference in material between the mounting member and the outer ring of the outer member prevents the bearing preload during assembly from being maintained and the occurrence of problems such as preload loss due to changes in the bearing clearance. While reducing weight It is possible to provide a wheel bearing apparatus that ensures the bearing life by preventing a change in the bearing clearance.

  Preferably, if the mounting member is made of an aluminum alloy or a magnesium alloy as in the invention described in claim 2, it is possible to reduce the weight by using a low specific gravity material.

  Further, as in the third aspect of the present invention, if the mounting member is formed by injection molding from a thermoplastic synthetic resin filled with a fibrous reinforcing material, further weight reduction can be achieved.

  According to a fourth aspect of the present invention, the outer end portion of the mounting member is formed to extend, and is opposed to the inner side surface of the wheel mounting flange via an axial clearance, and a labyrinth seal If m is formed, it is possible to prevent muddy water or the like from entering between the wheel mounting flange and the outer member.

  Further, if the expansion suppressing member is made of bearing steel, carbon steel, or case-hardened steel as in the invention described in claim 5, the bearing clearance changes and the bearing preload during assembly cannot be maintained. Thus, it is possible to prevent a problem such as a preload loss.

  Moreover, if the flange part extended radially outward is integrally formed in the edge part of the outer side of the said expansion | extension suppression member like invention of Claim 6, it will become an outer member during driving | running | working of a vehicle. It is possible to prevent the rainwater and muddy water from flowing along the outer peripheral surface from flowing between the wheel mounting flange and the outer member.

  In addition, if an annular groove is formed on the outer periphery of the outer end of the expansion suppressing member as in the invention described in claim 7, rainwater and muddy water applied to the outer member during traveling of the vehicle are Even if it travels on the surface, it can be discharged to the road surface side like a saddle and can be prevented from flowing between the wheel mounting flange and the outer member.

  Moreover, if the antirust film is formed in the surface of the said expansion | extension suppression member like invention of Claim 8, the rusting of an expansion | extension suppression member can be prevented and durability can be improved.

  Further, as in the invention according to claim 9, if the outer side end face of the outer member is opposed to the inner side face of the wheel mounting flange via an axial clearance, a labyrinth seal is formed. Further, it is possible to prevent muddy water or the like from directly entering the seal, and to improve the durability of the seal.

  Further, as in the invention described in claim 10, if the outer rolling surface of the double row is ground after the outer ring is press-fitted and fixed to the mounting member, the outer rolling of the double row by the press-fitting of the outer ring is performed. It is possible to prevent the dimensional change of the running surface and to easily adjust the bearing clearance. In addition, it is possible to reduce the cost by reducing the amount of high-purity and high-priced material used as the outer ring as much as possible, and to reduce the cost by eliminating grinding of the fitting surface of the mounting member.

    A wheel bearing device according to the present invention has a vehicle body mounting flange for mounting to a vehicle body on the outer periphery, an outer member having a double row outer raceway formed on the inner periphery, and a wheel mounted on one end. A hub wheel integrally having a wheel mounting flange for forming a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel through a shimishiro, An inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a cage is provided between both rolling surfaces of the inner member and the outer member. In a wheel bearing device including a double row rolling element accommodated in a freely rolling manner, the outer member integrally has the vehicle body mounting flange on the outer periphery, and a cylindrical fitting surface on the inner periphery. The formed annular mounting member and the fitting surface of the mounting member are fixed to the inner periphery. A steel outer ring integrally formed with a double row outer rolling surface, and the mounting member is made of a material having a specific gravity lower than that of steel, and an annular expansion suppression member is provided on the outer peripheral surface of the mounting member. Since the expansion suppressing member is press-fitted and formed of a material having a smaller linear expansion coefficient than the mounting member, even when the bearing temperature rises during traveling of the vehicle, the material of the mounting member and the outer ring in the outer member Due to the difference in linear expansion coefficient due to the difference in the bearing clearance, it is possible to prevent the occurrence of problems such as preload loss due to changes in the bearing clearance that prevent the bearing preload during assembly from being maintained. It is possible to provide a wheel bearing device that prevents a change and ensures a bearing life.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. It is a principal part enlarged view of FIG. It is a principal part enlarged view which shows the seal part of FIG. (A)-(c) is explanatory drawing which shows the manufacturing method of the outward member which concerns on this invention. 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 3rd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 4th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 5th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 6th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 7th 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. It is a longitudinal cross-sectional view which shows the outward member of FIG.

  It has a body mounting flange for mounting to the vehicle body on the outer periphery, and an outer member with a double row outer rolling surface formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end. A hub wheel having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, a small-diameter step portion extending in the axial direction from the inner rolling surface, and a small-diameter step portion of the hub ring An inner member comprising an inner ring that is press-fitted into the outer periphery of the double-row outer rolling surface and is opposed to the other of the outer rolling surfaces of the double row, and the inner member and the outer member. In the wheel bearing device having a double row rolling element that is rotatably accommodated between both rolling surfaces via a cage, the outer member integrally has the vehicle body mounting flange on the outer periphery. An annular mounting member having a cylindrical fitting surface formed on the inner periphery, and the mounting member A steel outer ring fixed to the fitting surface and integrally formed with the outer circumferential rolling surface of the double row on the inner periphery, and the mounting member is made of an aluminum alloy or a magnesium alloy, and the outer periphery of the mounting member An annular expansion suppression member is press-fitted into the surface, and the expansion suppression member is formed of bearing steel, carbon steel, or case-hardened steel having a rust preventive film formed on the surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is an enlarged main part of a seal part of FIG. 4A to 4C are explanatory views showing a method for manufacturing an outer member according to the present invention. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device is for a driven wheel called a third generation, and is an outer member 1 and an outer member externally inserted into the inner member 1 through double-row rolling elements (balls) 3. And a member 2. The inner member 1 includes a hub ring 4 and an inner ring 5 fixed to the hub ring 4.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface. A small diameter step 4b extending in the axial direction from the surface 4a is formed. Hub bolts 6a for fastening the wheels are planted at equal intervals in the circumferential direction of the wheel mounting flange 6.

  The inner ring 5 is made of a high carbon chrome bearing steel such as SUJ2, and the other (inner side) inner rolling surface 5a is formed on the outer periphery. The inner ring 5 is hardened in the range of 58 to 64 HRC to the core part by quenching. Then, a predetermined bearing preload is applied to the small-diameter step portion 4b of the hub wheel 4 through a predetermined squeeze, and the end portion of the small-diameter step portion 4b is plastically deformed radially outward. In the applied state, it is fixed in the axial direction with respect to the hub wheel 4. In addition, the rolling element 3 consists of high carbon chromium bearing steel, such as SUJ2, and is hardened in the range of 58-64HRC to the core part by the quenching quenching.

  The hub wheel 4 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and has a surface hardness by induction quenching from the base 6b on the inner side of the wheel mounting flange 6 to the small diameter step 4c. Is cured in the range of 58 to 64 HRC. The caulking portion 4c is an unquenched portion while maintaining the surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 6, and the wear resistance of the small-diameter step portion 4 b serving as the fitting portion of the inner ring 5 is improved, and caulking processing is performed. This prevents the occurrence of micro cracks or the like in the caulking portion 4c.

  The outer member 2 includes an annular mounting member 7 and an outer ring 8 press-fitted and fixed to the mounting member 7. The mounting member 7 is made of a material having a specific gravity lower than that of steel, such as an aluminum alloy or a magnesium alloy. The mounting member 7 integrally has a vehicle body mounting flange 7b for mounting to a knuckle on the outer periphery, and a cylindrical shape in which an outer ring 8 is fitted on the inner periphery. The fitting surface 7a is formed. Thereby, the outer member 2 can be reduced in weight.

  On the other hand, the outer ring 8 is made of high carbon chrome bearing steel such as SUJ2 like the inner ring 5 and has double rows of outer rolling surfaces 8a, 8a facing the inner rolling surfaces 4a, 5a of the inner member 1 on the inner periphery. Are integrally formed and hardened in the range of 58 to 64 HRC up to the core part by quenching. The double-row rolling elements 3 and 3 are accommodated between the rolling surfaces 8a and 4a and the rolling surfaces 8a and 5a, respectively, and are held by the cages 9 and 9 so as to be freely rollable.

  A seal 10 is attached to the outer opening of the annular space formed between the outer member 2 and the inner member 1, and a cap 11 is attached to the inner opening of the outer member 2. Is installed to prevent leakage of lubricating grease sealed in the bearing and prevent rainwater, dust, etc. from entering the bearing from the outside. In addition, although the wheel bearing comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, it is not restricted to this but is comprised by the double row tapered roller bearing which uses the tapered roller for the rolling element 3. It may be what was done.

  As shown in the enlarged view of FIG. 2, the attachment member 7 has a flange portion 7c integrally formed on the inner side of the fitting surface 7a, and an annular retaining ring groove 7d on the outer side of the fitting surface 7a. The outer ring 8 is positioned and fixed in the axial direction by the retaining ring 12 formed in this retaining ring groove 7d and the flange portion 7c.

  A pulsar ring 13 is press-fitted into the outer diameter surface 5 b of the inner ring 5. The pulsar ring 13 includes a support ring 14 formed in an annular shape, and a magnetic encoder 15 integrally joined to a side surface of the support ring 14 by vulcanization adhesion or the like. This magnetic encoder 15 constitutes a rotary encoder for detecting the rotational speed of a wheel by mixing magnetic powder such as ferrite in an elastomer such as rubber and magnetizing magnetic poles N and S alternately in the circumferential direction.

  The support ring 14 has a rust preventive ability such as a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like). It has a cylindrical portion 14a that is formed into a substantially L-shaped cross section by pressing from a steel plate and is press-fitted into the inner ring 5, and a standing plate portion 14b that extends radially outward from the cylindrical portion 14a. The magnetic encoder 15 is joined to the inner side surface of the upright plate portion 14b.

  As shown in an enlarged view in FIG. 3, the outer-side seal 10 includes a cored bar 16 that is press-fitted into the inner periphery of the outer-side end portion of the mounting member 7 through a predetermined shimiro, and vulcanizes the cored bar 16. It is composed of an integrated seal composed of a seal member 17 joined together by bonding. The metal core 16 is formed in a substantially L-shaped cross section by press working from an austenitic stainless steel plate or a cold-rolled steel plate that has been rust-proofed.

  On the other hand, the seal member 17 is made of a synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and extends while inclining radially outward. The seal member 17 is connected to the inner side surface 6c of the wheel mounting flange 6 via a predetermined axial shimiro. A side lip 17a that makes sliding contact, and a dust lip 17b that extends by inclining radially outward on the inner diameter side of the side lip 17a, and that makes sliding contact with a base portion 6b having an arcuate cross section via a predetermined axial squeeze And a grease lip 17c extending inwardly in the radial direction and in sliding contact with the base portion 6b via a predetermined radial nip. In addition to NBR, the material of the seal member 17 includes, for example, HNBR (hydrogenated acrylonitrile-butadiene rubber), EPM, EPDM (ethylene / propylene rubber), etc., which have excellent heat resistance, heat resistance and chemical resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in properties.

  A cap 11 is attached to the attachment member 7 and closes the opening on the inner side of the outer member 2. The cap 11 has corrosion resistance and is formed into a cup shape by pressing from a non-magnetic austenitic stainless steel plate so as not to adversely affect the sensing performance of a rotation speed sensor (not shown), as shown in FIG. A cylindrical fitting portion 11a that is press-fitted into the inner periphery of the inner end of the mounting member 7 and a magnetic encoder 15 facing the magnetic encoder 15 through a small diameter portion 11b from the fitting portion 11a via a slight axial clearance. And the bottom part 11c which covers the edge part by the side of the inner side of the inner member 1 is provided.

  An elastic member 18 made of synthetic rubber such as NBR is integrally joined to the reduced diameter portion 11b by vulcanization adhesion. The elastic member 18 includes an annular protrusion 18a that protrudes radially outward from the outer diameter of the fitting portion 11a. The annular protrusion 18a is elastically deformed and pressure-bonded to the attachment member 7 when the cap 11 is fitted, thereby improving the airtightness of the fitting portion 11a.

  Here, in this embodiment, the expansion suppressing member 19 is press-fitted into the outer peripheral surface 7 e of the mounting member 7. The expansion suppressing member 19 is formed in an annular shape by press working from a material having a smaller linear expansion coefficient than that of the mounting member 7, that is, a cold rolled steel plate or a carbon steel plate such as S45C. Not limited to this, the expansion suppressing member 19 may be formed of a pipe material made of bearing steel such as SUJ2 or carburized steel such as SCr420 or SCM415.

The term “linear expansion coefficient” as used herein refers to the rate at which the length and volume of an object expand as temperature rises per 1 K (° C.), and is also referred to as a thermal expansion coefficient or a thermal expansion coefficient. In general, this linear expansion coefficient is 60 × 10 ⁻⁶ / K for aluminum alloys, 10.9 × 10 ⁻⁶ / K for carbon steel, and 10.4 to 17.3 × for stainless steel. 10 ⁻⁶ / K, 20 to 100 × 10 ⁻⁶ / K for synthetic resin.

  In the present embodiment, since the expansion suppressing member 19 having a linear expansion coefficient smaller than that of the mounting member 7 is press-fitted into the outer peripheral surface 7e of the mounting member 7 constituting the outer member 2, the bearing temperature is increased during traveling of the vehicle. Even if it rises, due to the difference in linear expansion coefficient due to the difference in material between the mounting member 7 and the outer ring 8 in the outer member 2, the bearing clearance changes and the bearing preload at the time of assembly cannot be maintained, causing a problem such as preload loss. Thus, it is possible to provide a wheel bearing device that can prevent the occurrence and reduce the weight while preventing the change of the bearing clearance and ensuring the bearing life.

  Note that a rust-preventing film is formed on the surface of the expansion suppressing member 19 by cationic electrodeposition coating. This rust preventive film is not limited to cationic electrodeposition coating, but may be another coating film, or may be a plating treatment. For example, anti-rust treatment such as radiant coating, anion electrodeposition coating, fluorine electrodeposition coating, or zinc plating, unichrome plating, chromate plating, nickel plating, nickel zinc plating, chromium plating, electroless nickel plating, kanigen plating, etc. The metal plating can be exemplified. Thereby, rusting of the expansion suppressing member 19 can be prevented and durability can be improved. In addition, you may form the expansion suppression member 19 itself with the stainless steel which has rust prevention ability.

Next, the manufacturing method of the outer member 2 is demonstrated using FIG.
As shown in FIG. 4A, the outer peripheral surface 7e, the fitting surface 7a, the flange portion 7c, the inner peripheral surface such as the retaining ring groove 7d, as well as the vehicle body mounting flange 7b of the mounting member 7 constituting the outer member 2 are shown. Are formed by turning. Then, the outer ring 8 ′ is press-fitted into the fitting surface 7a, the retaining ring 12 is mounted in the retaining ring groove 7d, and the outer ring 8 ′ is positioned and fixed by the retaining ring 12 and the flange portion 7c.

  Here, the fitting surface 7a of the mounting member 7 may be ground after turning, but in the present embodiment, the fitting surface 7a remains turned. In addition, the outer ring 8 ′ is turned in a state where the outer surface 8b and the width surface 8c of the double row outer rolling surfaces 8a ′ and 8a ′ leave the grinding allowance, and after being heat-treated (submerged), the outer ring 8 ′ The outer peripheral surface 8b and the width surface 8c excluding the outer rolling surfaces 8a ′ and 8a ′ of the row are ground.

  Next, as shown in (b), after the outer ring 8 ′ is press-fitted and fixed to the mounting member 7, the outer ring 8 ′ is fully fitted to the outer ring 8 ′ in a state where the shoe 20 is in sliding contact with the outer peripheral surface 7e of the mounting member 7. The grinding wheel 21 is inserted. The outer peripheral surface 7e with which the shoe 20 is slidably contacted is previously finished to a predetermined shape and size by grinding. Then, as shown in (c), the double-row outer rolling surfaces 8a ′ and 8a ′ are simultaneously ground by the grinding wheel 21 formed in a predetermined shape and size, and at the same time by a super grindstone (not shown). -Finished to dimensions.

  Thus, after the outer ring 8 is press-fitted and fixed to the mounting member 7, the double-row outer rolling surfaces 8 a and 8 a are ground, so the dimensions of the double-row outer rolling surfaces 8 a and 8 a due to the press-fitting of the outer ring 8. The change can be prevented and the clearance of the bearing can be easily adjusted. Further, the amount of use of an expensive material with high cleanliness used as the outer ring 8 is reduced as much as possible, and the cost is reduced by eliminating grinding of the fitting surface 7a of the mounting member 7. Can do.

  FIG. 5 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention. The second embodiment is basically different from the above-described embodiment (FIG. 1) only in the method of fixing the expansion suppressing member, and other parts and parts having the same function or the same function are not used. The same reference numerals are assigned and detailed description thereof is omitted.

  This wheel bearing device is for a driven wheel called a third generation, and includes an inner member 1, and an outer member 22 externally inserted into the inner member 1 via double-row rolling elements 3. It has.

  The outer member 22 includes an annular mounting member 23 and an outer ring 8 press-fitted and fixed to the mounting member 23. The mounting member 23 is made of a material having a specific gravity lower than that of steel, such as an aluminum alloy or a magnesium alloy. The mounting member 23 has a body mounting flange 7b integrally on the outer periphery, and a cylindrical fitting surface 7a on which the outer ring 8 is fitted on the inner periphery. Is formed.

  The attachment member 23 is integrally formed with a flange 7c on the inner side of the fitting surface 7a, and an annular retaining ring groove 7d is formed on the outer side of the fitting surface 7a, and is attached to the retaining ring groove 7d. The outer ring 8 is positioned and fixed in the axial direction by the retaining ring 12 and the flange portion 7c.

  Here, in this embodiment, the expansion suppressing member 24 is press-fitted into the outer peripheral surface 7 e of the mounting member 23. A retaining ring groove 23a is formed at the outer end of the outer peripheral surface 7e, and the expansion suppressing member 24 is fixed in the axial direction by a retaining ring 25 attached to the retaining ring groove 23a. The expansion suppression member 24 is formed in an annular shape with a material having a smaller linear expansion coefficient than the mounting member 23 as in the above-described embodiment.

  Thus, in this embodiment, since the expansion suppressing part 24 having a smaller linear expansion coefficient than the mounting member 23 is positioned and fixed to the outer peripheral surface 7e of the mounting member 23 constituting the outer member 22, the vehicle is running. Even when the bearing temperature rises, it is possible to prevent the occurrence of problems such as preload loss, and it is possible to reduce the press-fitting scissors and simplify the assembling work, thereby reducing the cost.

  FIG. 6 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention. The third embodiment is basically the same as the second embodiment (FIG. 5) described above except that the configuration of the mounting member and the expansion suppressing member is only partially different, and the same parts or the same functions. Parts and parts having the same reference numerals are given the same reference numerals, and detailed description thereof is omitted.

  This wheel bearing device is for a driven wheel referred to as a third generation, and includes an inner member 1, and an outer member 26 inserted on the inner member 1 via double row rolling elements 3. It has.

  The outer member 26 includes an annular mounting member 27 and an outer ring 8 that is press-fitted and fixed to the mounting member 27. The mounting member 27 is made of a material having a specific gravity lower than that of steel, such as an aluminum alloy or a magnesium alloy. The mounting member 27 has a body mounting flange 7b integrally on the outer periphery, and a cylindrical fitting surface 7a on which the outer ring 8 is fitted on the inner periphery. Is formed.

  The attachment member 27 is integrally formed with a flange portion 7c on the inner side of the fitting surface 7a, and an annular retaining ring groove 7d is formed on the outer side of the fitting surface 7a, and is attached to the retaining ring groove 7d. The outer ring 8 is positioned and fixed in the axial direction by the retaining ring 12 and the flange portion 7c.

  An expansion suppression member 28 is press-fitted into the outer peripheral surface 7e of the mounting member 27, and the expansion suppression member 28 is fixed in the axial direction by a retaining ring 25 attached to the retaining ring groove 23a. This expansion suppression member 28 is formed in an annular shape with a material having a smaller linear expansion coefficient than the mounting member 27, as in the above-described embodiment.

  Here, in the present embodiment, a flange portion (weir portion) 28 a extending radially outward is integrally formed at the outer end portion of the expansion suppressing member 28. This flange portion 28a can prevent rainwater and muddy water applied to the outer member 26 during traveling of the vehicle from flowing between the wheel mounting flange 6 and the outer member 26 along the outer peripheral surface.

  Further, the outer end portion 27a of the mounting member 27 is formed to extend, and is opposed to the inner side surface 6c of the wheel mounting flange 6 through a slight axial clearance to form a labyrinth seal 29. Thereby, it is possible to prevent muddy water or the like from entering between the wheel mounting flange 6 and the outer member 26, and improve the durability of the seal 10 in combination with the flange portion 28 a of the expansion suppressing member 28. The sealing performance can be maintained over a long period of time.

  FIG. 7 is a longitudinal sectional view showing a fourth embodiment of the wheel bearing device according to the present invention. The fourth embodiment is basically different from the third embodiment (FIG. 6) described above except that the configuration of the mounting member is partially different, and other parts having the same parts or the same functions. Parts are denoted by the same reference numerals and detailed description thereof is omitted.

  This wheel bearing device is for a driven wheel called a third generation, and includes an inner member 1 and an outer member 30 inserted on the inner member 1 via double-row rolling elements 3. It has.

  The outer member 30 includes an annular mounting member 27 and an outer ring 8 press-fitted and fixed to the mounting member 27. The mounting member 27 is made of a material having a specific gravity lower than that of steel, such as an aluminum alloy or a magnesium alloy. The mounting member 27 has a body mounting flange 7b integrally on the outer periphery, and a cylindrical fitting surface 7a on which the outer ring 8 is fitted on the inner periphery. Is formed.

  The attachment member 27 is integrally formed with a flange portion 7c on the inner side of the fitting surface 7a, and an annular retaining ring groove 7d is formed on the outer side of the fitting surface 7a, and is attached to the retaining ring groove 7d. The outer ring 8 is positioned and fixed in the axial direction by the retaining ring 12 and the flange portion 7c.

  The expansion suppression member 31 is press-fitted into the outer peripheral surface 7e of the mounting member 27, and the expansion suppression member 31 is fixed in the axial direction by a retaining ring 25 attached to the retaining ring groove 23a. The expansion suppression member 31 is formed in an annular shape with a material having a smaller linear expansion coefficient than the mounting member 27, as in the above-described embodiment.

  Here, in the present embodiment, the annular groove 31 a is formed on the outer periphery of the outer end portion of the expansion suppressing member 31. Even if rain water or muddy water applied to the outer member 30 during traveling of the vehicle travels along the outer peripheral surface by the annular groove 31a, it can be discharged to the road surface side like a kite, and the wheel mounting flange 6 and the outer It can prevent flowing between the members 30.

  FIG. 8 is a longitudinal sectional view showing a fifth embodiment of the wheel bearing device according to the present invention. The fifth embodiment is basically the same as the first embodiment (FIG. 1) described above except that the configuration of the expansion suppression member is only partially different, and other parts having the same parts or the same functions. The same reference numerals are given to the parts and the detailed description thereof is omitted.

  This wheel bearing device is for a driven wheel referred to as a third generation, and includes an inner member 1 and an outer member 32 externally inserted into the inner member 1 via double-row rolling elements 3. It has. The outer member 32 includes an annular mounting member 7 and an outer ring 8 press-fitted and fixed to the mounting member 7.

  The expansion suppression member 33 that is press-fitted and fixed to the outer peripheral surface 7e of the attachment member 7 is formed in an annular shape with a material having a smaller linear expansion coefficient than the attachment member 7, as in the above-described embodiment. The expansion suppressing member 33 is formed to extend to the outer side, and faces the inner side surface 6c of the wheel mounting flange 6 via a slight axial clearance to form a labyrinth seal 34. As a result, muddy water or the like can be prevented from entering between the wheel mounting flange 6 and the outer member 32, and the durability of the seal 10 can be improved and the sealing performance can be maintained over a long period of time. it can.

  FIG. 9 is a longitudinal sectional view showing a sixth embodiment of the wheel bearing device according to the present invention. The sixth embodiment is basically different from the first embodiment (FIG. 1) described above except that the configuration of the bearing portion is different, and other parts or parts having the same function or the same function are used. Are given the same reference numerals and their detailed description is omitted.

  This wheel bearing device is for a driven wheel referred to as a third generation, and includes an inner member 35 and an outer member 36 externally inserted into the inner member 35 via double-row rolling elements 3. It has. The inner member 35 includes a hub ring 4 and an inner ring 37 fixed to the hub ring 4.

  The inner ring 37 is made of a high carbon chrome bearing steel such as SUJ2, and an inner rolling surface 37a is formed on the outer periphery. The inner ring 37 is hardened in the range of 58 to 64 HRC to the core part by quenching. Then, a predetermined bearing preload is applied to the small-diameter step portion 4b of the hub wheel 4 through a predetermined squeeze, and the end portion of the small-diameter step portion 4b is plastically deformed radially outward. In the applied state, it is fixed in the axial direction with respect to the hub wheel 4.

  The outer member 36 includes an annular mounting member 7 and an outer ring 38 press-fitted and fixed to the mounting member 7. The outer ring 38 is made of a high carbon chrome bearing steel such as SUJ2, and the outer circumferential surface 8a, 38a of the double row facing the inner rolling surfaces 4a, 37a of the inner member 35 is integrally formed on the inner periphery. The core is hardened in the range of 58 to 64 HRC by quenching. And the double row rolling elements 3 and 3 are accommodated between these rolling surfaces 8a and 4a and rolling surfaces 38a and 37a, respectively, and are hold | maintained by the holder | retainers 9 and 39 so that rolling is possible.

  Here, in the present embodiment, the pitch circle diameter PCDi of the inner side ball 3 is set larger than the pitch circle diameter PCDo of the outer side ball 3. The outer diameters of the double-row balls 3 and 3 are the same, but due to the difference in the pitch circle diameters PCDo and PCDi, the number of inner-side balls 3 is set larger than the number of outer-side balls 3. Yes. Thereby, compared with the outer side, the bearing rigidity of the inner side part to which a big moment load is loaded increases, and the lifetime of a bearing can be extended.

  FIG. 10 is a longitudinal sectional view showing a seventh embodiment of the wheel bearing device according to the present invention. The seventh embodiment is basically the same as the first embodiment (FIG. 1) described above except that the configuration of the bearing portion is different, and other parts or parts having the same function or the same function are used. Are given the same reference numerals and their detailed description is omitted.

  This wheel bearing device is for a driven wheel called the first generation, and is press-fitted into the hub wheel 40 and the hub wheel 40 so that the hub wheel 40 can be rotatably supported with respect to a knuckle (not shown). The wheel bearing 41 is mainly configured.

  The wheel bearing 41 is composed of an outer member 42, a pair of inner rings 5, 5 inserted in the outer member 42, and double row rolling elements housed between the inner rings 5, 5 and the outer ring 8. 3 and 3. The outer member 42 includes an annular mounting member 43 and an outer ring 8 that is press-fitted and fixed to the mounting member 43.

  The attachment member 43 is formed by injection molding a thermoplastic synthetic resin such as PA (polyamide) 66 filled with 10 to 40 wt% of a fibrous reinforcing material such as GF (glass fiber). Further, a body fitting flange 43b is integrally formed on the outer periphery, and a cylindrical fitting surface 43a on which the outer ring 8 is fitted is formed on the inner periphery.

  In addition to the above-mentioned PA66, the mounting member 43 is made of a thermoplastic synthetic resin called so-called engineering plastic such as PPA (polyphthalamide) or PBT (polybutylene terephthalate), polyphenylene sulfide (PPS), poly Thermoplastic synthetic resins called so-called super engineering plastics such as ether ether ketone (PEEK) and polyamideimide (PAI), or heat such as phenol resin (PF), epoxy resin (EP), polyimide resin (PI), etc. A curable synthetic resin may be used. Further, it may be a biodegradable synthetic resin that reduces the environmental load. Examples of the components of this biodegradable synthetic resin include polylactic acid, polycaprolactone, polyglycolic acid, modified polyvinyl alcohol, and casein. Moreover, as a fibrous reinforcement, not only GF but CF (carbon fiber), an aramid fiber, a boron fiber, etc. can be illustrated.

  A flange 43c is integrally formed on the inner side of the fitting surface 43a of the mounting member 43, and an annular retaining ring groove 43d is formed on the outer side of the fitting surface 43a, and is attached to the retaining ring groove 43d. The outer ring 8 is positioned and fixed in the axial direction by the retaining ring 12 and the flange 43c. Further, the expansion suppressing member 19 is press-fitted and fixed to the outer peripheral surface 43 e of the mounting member 43.

  A seal 44 is attached to the opening of the annular space formed between the attachment member 43 and the inner ring 5 on the outer side, and a cap 11 is attached to the opening on the inner side of the attachment member 43, so Leakage of the lubricating grease sealed in and prevention of rainwater and dust from entering the bearing from the outside. The seal 44 is constituted by a so-called pack seal, which is a composite seal composed of an annular seal plate 45 and a slinger 46 arranged to face each other.

  Also in the present embodiment, as in the above-described embodiment, after the outer ring 8 is press-fitted and fixed to the mounting member 43, the double row outer rolling surfaces 8a and 8a are ground. Thereby, the dimensional change of the double row outer rolling surfaces 8a, 8a due to the press-fitting of the outer ring 8 can be prevented, and the bearing clearance can be easily adjusted. In addition, the amount of expensive and high-purity material used as the outer ring 8 can be reduced as much as possible to reduce the cost.

  In the present embodiment, since the synthetic resin that can be injection-molded is used for the mounting member 43, it can be insert-molded integrally with the outer ring 8. This eliminates the need for additional work for the retaining ring groove 43d, and can reduce not only the processing man-hours but also the assembly man-hours, thereby further reducing the cost.

  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 having a first to third generation structure regardless of whether it is for driving wheels or driven wheels.

DESCRIPTION OF SYMBOLS 1, 35 Inner member 2, 22, 26, 30, 36, 42 Outer member 3 Rolling element 4, 40 Hub wheel 4a, 5a, 37a Inner rolling surface 4b Small diameter step part 4c Clamping part 5, 37 Inner ring 5b Outer diameter surface 6 Wheel mounting flange 6a Hub bolt 6b Base 6c on the inner side of the wheel mounting flange Side surfaces 7, 23, 27, 43 on the inner side of the wheel mounting flange Mounting members 7a, 43a Fitting surfaces 7b, 43b Car body mounting flange 7c, 43b ridges 7d, 23a, 43d retaining ring grooves 7e, 43e outer peripheral surfaces 8, 8 ', 38 outer ring 8a, 8a', 38a outer rolling surface 8b outer diameter surface 8c outer ring width surface 9, 39 holding outer ring Containers 10 and 44 Seal 11 Cap 11a Fitting portion 11b Reduced diameter portion 11c Bottom portions 12 and 25 Retaining ring 13 Pulsar ring 14 Support ring 14a Cylindrical portion 14b Standing plate portion 15 Magnetic encoder 16 Metal core 17 Seal member 17a Side lip 17b Dustrip 17c Grease lip 18 Elastic member 18a Annular projections 19, 24, 28, 31, 33 Expansion restraining member 20 Shoe 21 Grinding wheel 27a End 28a on the outer side of the mounting member Flange 29 , 34 Labyrinth seal 31a Annular groove 45 Annular seal plate 46 Slinger 51 Wheel bearing device 52 Inner member 53 Outer member 54 Ball 55 Hub wheel 55a Wheel mounting flange 55b, 56a Inner rolling surface 55c Small diameter step 56 Inner ring 57 Mounting member 58 Outer ring 58a Outer rolling surface 58b Thick part 59 Car body mounting flange 59a Base 59b Knuckle mounting part 60 Insertion hole 61 Female threaded hole 62 Fixing member PCDi Pitch diameter of rolling element on inner side PCDo Pitch of rolling element on outer side Circle diameter W Minimum outer ring thickness

Claims (10)

An outer member having a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and a double row outer rolling surface formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end, and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least press-fitted into the small-diameter step portion of the hub wheel via a shimoshiro An inner member formed of one inner ring, and formed on the outer periphery with a double row inner rolling surface facing the double row outer rolling surface;
In a wheel bearing device comprising a double-row rolling element that is accommodated so as to roll freely between both rolling surfaces of the inner member and the outer member via a cage,
The outer member integrally has the vehicle body mounting flange on the outer periphery, and an annular mounting member in which a cylindrical fitting surface is formed on the inner periphery, and is fixed to the fitting surface of the mounting member. A steel outer ring integrally formed with the outer circumferential surface of the double row on the periphery, and the mounting member is made of a material having a specific gravity lower than that of steel, and an annular expansion suppression is provided on the outer peripheral surface of the mounting member. A wheel bearing device, wherein a member is press-fitted and the expansion suppression member is formed of a material having a smaller linear expansion coefficient than the mounting member.   The wheel bearing device according to claim 1, wherein the mounting member is formed of an aluminum alloy or a magnesium alloy.   The wheel bearing device according to claim 1, wherein the mounting member is formed by injection molding from a thermoplastic synthetic resin filled with a fibrous reinforcing material.   4. The labyrinth seal according to claim 1, wherein an outer end portion of the mounting member is formed so as to extend, is opposed to an inner side surface of the wheel mounting flange via an axial clearance, and a labyrinth seal is formed. The wheel bearing device described.   The wheel bearing device according to claim 1, wherein the expansion suppression member is formed of bearing steel, carbon steel, or case-hardened steel.   The wheel bearing device according to claim 1 or 5, wherein a flange portion extending radially outward is integrally formed at an outer end portion of the expansion suppressing member.   The wheel bearing device according to claim 1 or 5, wherein an annular groove is formed on an outer periphery of an outer end portion of the expansion suppressing member.   The wheel bearing device according to claim 1, wherein a rust preventive film is formed on a surface of the expansion suppressing member.   2. The wheel bearing device according to claim 1, wherein an outer end face of the outer member is opposed to an inner side face of the wheel mounting flange via an axial clearance, and a labyrinth seal is formed.   The wheel bearing device according to claim 1, wherein the outer raceway of the double row is ground after the outer ring is press-fitted and fixed to the mounting member.

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