JP4940027B2 - Wheel bearing device - Google Patents

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 a vehicle such as an automobile, and more particularly, to a wheel bearing device that achieves weight reduction, compactness, and cost reduction and also improves bearing durability. Is.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like supports a hub wheel for mounting a wheel rotatably via a double row rolling bearing, and includes a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and both an inner ring rotation method and an outer member rotation method are generally used for driven wheels. This 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, and is an outer member. 2nd generation structure with body mounting flange or wheel mounting flange formed directly on the outer periphery of the wheel, 3rd generation structure with one inner rolling surface formed directly on the outer periphery of the hub wheel, or constant speed with the hub wheel It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the universal joint.

  Conventionally, an angular ball bearing having a structure in which an inner ring and an outer ring are formed from a steel plate by pressing is known. For example, the angular ball bearing 50 shown in FIG. 5 is used in a magnetic hard disk device or the like, but the outer ring (outer member) 51 and the pair of inner rings 52 and 53 are made of stainless steel by pressing or rolling. Is formed.

  The outer ring 51 is formed with an annular convex portion 51a protruding radially inward at a substantially middle portion of the inner peripheral surface, and outer rolling surfaces 51b and 51c are formed on inner peripheral surfaces on both sides of the annular convex portion 51a. Yes. The outer ring 51 has an outer peripheral surface fitted into a hole in the housing 54, and a flange 51 d formed at one end is brought into contact with the end surface of the housing 54 to perform axial positioning. An annular recess 51e is formed on the outer peripheral surface of the outer ring 51 by the annular protrusion 51a. The annular recess 51e is filled with an adhesive, and the outer ring 51 is fixed to the hole of the housing 54.

  On the other hand, the inner rings 52 and 53 are respectively fitted inside the double row outer raceway surfaces 51b and 51c of the outer ring 51 from both sides in the axial direction. Curved shoulder portions 52a and 53a are formed on the outer circumferences of the outer ends in the axial direction of the inner rings 52 and 53, and inner rolling surfaces 52b and 53b are formed on the curved shoulder portions 52a and 53a. The double rows of balls 56, 56 are arranged between the inner rolling surfaces 52b, 53b and the outer rolling surfaces 51b, 51c of the outer ring 51, and are retained by the cages 57, 57 for each row. Is retained.

  On the inner peripheral surfaces of the inner rings 52 and 53, fitting portions 52c and 53c that are fitted into the shaft member 55 with clearance are formed. After the inner rings 52, 53 are fitted into the shaft member 55 in the axial direction, a cylindrical weight 59 having a constant weight is placed on the curved shoulder 52 a of one inner ring 52, and the weight of the weight 59 The other inner ring 53 is pressed via the inner ring 52, the ball 56, the outer ring 51, and the ball 56, and the curved shoulder portion 53 a is fitted until it comes into contact with the flange portion 55 a of the shaft member 55. Thereby, an appropriate preload is set for the angular ball bearing 50.

When this gap fitting is completed, the adhesive 60 is filled in the gap between the curved shoulder portion 52a of the one inner ring 52 and the shaft member 55, and this adhesive 60 prevents the one inner ring 52 from being fitted off. The flange portion 55a of the shaft member 55 prevents the other inner ring 53 from being fitted off.
Japanese Utility Model Publication No. 6-1835

  When this type of angular contact ball bearing 50 made of a press is used as a wheel bearing, if the initial preload amount of the angular ball bearing 50 is set high in order to prevent preload loss, it is a matter of course that extra angular ball bearing 50 is added. The bearing life is shortened because the load is always applied. Further, the bearing rigidity varies as the preload amount greatly changes due to temperature change, which adversely affects the running stability of the vehicle. Furthermore, if the initial squeeze is set large in order to prevent creep, the angular contact ball bearing 50 may be gnawed when the angular ball bearing 50 is press-fitted. It is necessary to press fit. This increases the number of assembly steps and causes a cost increase. Here, creep refers to a phenomenon in which the bearing surface slightly moves in the circumferential direction due to a lack of mating squealing or poor mating surface processing accuracy, and the mating surface becomes a mirror surface, and in some cases, seizure or welding occurs with galling. .

  The present invention has been made in view of such circumstances, and is mounted on a light alloy knuckle that is reduced in weight to reduce weight, reduce size, reduce costs, reduce preload due to temperature rise, and reduce bearing creep. It aims at providing the bearing device for wheels which prevented.

In order to achieve such an object, the invention according to claim 1 of the present invention has a wheel mounting flange for mounting a wheel at one end portion, and axially extends from the wheel mounting flange via a shoulder portion. A hub wheel formed with an extending small-diameter stepped portion, an outer joint member of a constant velocity universal joint fitted into the hub wheel via serrations, a knuckle constituting a suspension device, and a small diameter of the knuckle and the hub wheel A wheel bearing device fitted with a predetermined squeeze between the stepped portion and a wheel bearing device in which the hub wheel is rotatably supported with respect to the knuckle via the wheel bearing; The wheel bearing has an annular recess at the center of the outer periphery , protrudes radially inward at the inner periphery, and has an annular protrusion with an inner diameter formed in a flat shape, and double rows on both sides of the annular protrusion . Arc-shaped outer rolling surface is formed integrally An outer member, an inner raceway surface arcuate opposed to the outer rolling run side of double row outer periphery, a pair of inner ring shoulder portion is formed to extend from the large diameter side of the inner raceway surface in the axial direction And the inner ring and a double row of balls accommodated between both rolling surfaces of the outer member, and the pair of inner rings collide with their small diameter side end faces in abutting state so that the large diameter of the inner ring The side end surface is composed of a back-to-back type double row angular contact ball bearing that is sandwiched between the shoulder portion of the hub wheel and the shoulder portion of the outer joint member and is provided with a predetermined bearing preload. A plastic band made of pipe material is formed by plastic working, and a resin band made of heat-resistant synthetic resin is filled in the annular recess of the outer member by injection molding.

As described above, a hub wheel having a wheel mounting flange at one end and a small-diameter step portion extending in the axial direction from the wheel mounting flange via the shoulder is formed, and the hub wheel is internally fitted via serrations. In the wheel bearing device of the first generation structure provided with the outer joint member, the knuckle constituting the suspension device, and the wheel bearing fitted between the knuckle and the small diameter step portion, An annular convex portion having an annular recess at the center of the outer periphery , projecting radially inward at the inner periphery, and having an inner diameter formed in a flat shape, and double-row arc-shaped outer rolls on both sides of the annular convex portion. An outer member integrally formed with a running surface, an arc-shaped inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a shoulder extending in the axial direction from the large diameter side of the inner rolling surface a pair of inner ring part is formed, housed between the two rolling surfaces of the outer member and the inner ring And a ball of double columns, a pair of inner rings, the large diameter side end face of the inner ring abuts with the small diameter side end face abutting state of that is the shoulder of the shoulder portion and the outer joint member of the hub This is a back- to- back type double row angular contact ball bearing that is sandwiched and applied with a predetermined bearing preload , and the outer member and inner ring are formed from a pipe material by plastic working, and the annular recess of the outer member is heat resistant. Since the resin band made of synthetic resin is filled by injection molding, even if the knuckle expands more than the wheel bearing due to the difference in the linear expansion coefficient between the knuckle and the wheel bearing when the temperature rises, It is possible to suppress the decrease and prevent the occurrence of bearing creep, and also to prevent the initial bearing preload from decreasing, and to keep the running stability of the vehicle by suppressing the fluctuation of the bearing rigidity. Can That.

  Preferably, as in the invention described in claim 2, if the knuckle is made of a light alloy and the linear expansion coefficient of the resin band is set larger than the linear expansion coefficient of the knuckle, the squeezing drop due to temperature rise is reduced. Can be prevented.

  Further, as in the invention described in claim 3, if the outer diameter of the resin band is formed so as to protrude from 0 to 50 μm from the outer diameter of the outer ring, it is possible to reliably prevent the lowering of the shimeshiro due to the temperature rise. At the same time, a decrease in the rigidity of the resin band can be suppressed.

  Further, as in the invention described in claim 4, a shoulder portion extending in the axial direction from the large diameter side of the inner raceway surface of the inner ring is formed, and an annular recess extending from the inner peripheral surface of the shoulder portion to the chamfered portion is formed. If a resin band made of a heat-resistant synthetic resin is filled by injection molding, preload loss can be effectively prevented.

  Preferably, as in the invention described in claim 5, if the resin band is formed so as to protrude from the large-diameter side end surface of the inner ring by 0 to 50 μm, the preload is surely prevented and set to the initial stage. Bearing preload can be maintained over a long period of time.

  If the outer member and the inner ring are formed by cold rolling from the pipe material as in the invention described in claim 6, the thickness can be made substantially uniform and the shape and dimensions can be made. Can be ensured with a predetermined accuracy.

Further, as in the invention described in claim 7, when the resin band is made of a polyamide-based synthetic resin and the linear expansion coefficient is set to 8 to 16 × 10 ⁻⁵ / ° C., at least the fitting is performed. Even if this member is larger than the linear expansion coefficient of the member, and the member is thermally expanded more than the wheel bearing, the resin band can be further expanded to follow the change.

A wheel bearing device according to the present invention has a wheel mounting flange for mounting a wheel at one end, and a hub wheel formed with a small-diameter step portion extending axially from the wheel mounting flange via a shoulder. An outer joint member of a constant velocity universal joint fitted into the hub ring via serrations, a knuckle constituting a suspension device, and a predetermined squeezing between the knuckle and the small-diameter step portion of the hub ring. A wheel bearing device, wherein the hub wheel is rotatably supported with respect to the knuckle through the wheel bearing. A ring-shaped concave part, projecting inward in the radial direction on the inner periphery, and having a flat inner diameter, and a double-row arc-shaped outer rolling surface on both sides of the annular convex part. The formed outer member and the double row on the outer periphery And inner raceway surface arcuate opposed to the outer rolling run surface, a pair of inner ring shoulder portion is formed to extend from the large diameter side of the inner raceway surface in the axial direction, both of the outer member and the inner ring A plurality of balls accommodated between the rolling surfaces, and the pair of inner races abut each other in a state where the small-diameter side end surfaces abut each other so that the large-diameter side end surface of the inner race is in contact with the shoulder of the hub wheel. It consists of a back-to-back type double row angular contact ball bearing that is sandwiched between the shoulders of the outer joint member and applied with a predetermined bearing preload, and the outer member and the inner ring are formed from a pipe material by plastic working, and the outer Since the resin band made of heat-resistant synthetic resin is filled in the annular recess of the side member by injection molding, due to the difference in linear expansion coefficient between the knuckle and the outer member, the knuckle and the outer member There is a decrease in the fitting shimoshiro Can will not be released, it is maintained over the bearing preload during assembly a long period of time to prevent preload loss. Furthermore, it is possible to reliably prevent the outer member from creeping and seizing or inducing a short life.

  A hub wheel that integrally has a wheel mounting flange for mounting a wheel at one end, and has a small-diameter step portion extending in an axial direction from the wheel mounting flange through a shoulder portion, and a serration on the hub wheel via a serration For a wheel fitted with a predetermined squeeze between the outer joint member of a constant velocity universal joint fitted inside, a knuckle made of a light alloy constituting a suspension device, and the small-diameter step portion of the hub wheel. A wheel bearing device in which the hub wheel is rotatably supported with respect to the knuckle via the wheel bearing. The wheel bearing has an annular recess at the center of the outer periphery. An outer member in which a double row arc-shaped outer rolling surface is integrally formed on the inner periphery, an arc-shaped inner rolling surface facing the outer surface of the double row on the outer periphery, and the inner rolling surface. A shoulder extending in the axial direction from the large diameter side of the running surface is formed. A pair of inner rings and a double row of balls accommodated between both inner rings and the rolling surfaces of the outer member, and the pair of inner rings abut each other with their small diameter side end faces butting the hub. It consists of a back-to-back type double row angular contact ball bearing that is sandwiched between the shoulder of the ring and the shoulder of the outer joint member and applied with a predetermined bearing preload, and the outer member and the inner ring are A resin band made of heat-resistant synthetic resin is filled in the annular recess of the outer member and the annular recess extending from the inner peripheral surface of the shoulder portion of the inner ring to the chamfered portion by injection molding. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view showing the wheel bearing of FIG. 1, and FIG. 3 (a) is a single outer member of FIG. FIG. 4B is a longitudinal sectional view showing a single inner ring of FIG. 2, and FIG. 4 is a relationship between a temperature change of a conventional wheel bearing and the wheel bearing according to the present embodiment and a change in bearing preload. It is a graph which shows the result of having carried out comparative measurement. 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 shown in FIG. 1 mainly includes a hub wheel 1 and a wheel bearing 3 that is press-fitted into the hub wheel 1 and rotatably supports the hub wheel 1 with respect to the knuckle 2. The hub wheel 1 includes a wheel mounting flange 4 for mounting the wheel W and the brake rotor B to an end portion on the outer side, and a cylindrical small-diameter step portion 5 extending in an axial direction from the wheel mounting flange 4 via a shoulder portion 1a. Is formed. Hub bolts 4 a that fasten the wheels W and the brake rotor B are planted on the wheel mounting flange 4 at equal intervals in the circumferential direction. A serration (or spline) 6 is formed on the inner peripheral surface of the hub wheel 1, and a wheel bearing 3 described later is press-fitted on the outer peripheral surface of the small diameter step portion 5.

  The hub wheel 1 is formed of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and remains raw after forging. In addition, in order to increase the fatigue strength with respect to the bending strength, a method of performing a tempering treatment after forging, or a hardening treatment in the range of 58 to 64 HRC by induction hardening from the shoulder portion 1a to the small diameter step portion 5 is performed. You may do it.

  The wheel bearing 3 is fixed in a state of being sandwiched between the shoulder 9 of the outer joint member 8 constituting the constant velocity universal joint 7 and the shoulder 1 a of the hub wheel 1. The outer joint member 8 is integrally formed with a stem portion 10 extending in the axial direction from the shoulder portion 9. A serration (or spline) 10a that engages with the serration 6 of the hub wheel 1 and a male screw 10b at the end of the serration 10a are formed on the outer periphery of the stem portion 10 to drive torque from the engine (not shown) It is transmitted to the hub wheel 1 through the constant velocity universal joint 7 and the serrations 6 and 10a.

  Here, the serration 10 a is provided with a torsion angle inclined at a predetermined angle with respect to the axis, and the stem portion 10 is fitted into the hub wheel 1 until the shoulder portion 9 of the outer joint member 8 abuts against the wheel bearing 3. The hub ring 1 is press-fitted into the serration 6. Thereby, the preload is given to the fitting part of the serrations 6 and 10a, and the play of the circumferential direction is killed. Further, the hub wheel 1 and the constant velocity universal joint 3 are separated in a state where the fixing nut 11 is fastened to the male screw 10b formed at the end portion of the stem portion 10 with a predetermined tightening torque and a desired bearing preload is applied. It is combined as possible.

  On the other hand, the knuckle 2 is formed of a light alloy such as an aluminum alloy. As a result, compared with conventional cast iron or the like, even if each part is designed to be thick in order to compensate for the lack of rigidity, its weight is halved. A wheel bearing 3 is press-fitted into the knuckle 2 with a predetermined scissors.

  As shown in an enlarged view in FIG. 2, the wheel bearing 3 includes an outer member 12 in which double-row arc-shaped outer rolling surfaces 12 a and 12 a are integrally formed on the inner periphery, and these double-rows on the outer periphery. A pair of inner rings 13, 13 formed with arc-shaped inner rolling surfaces 13 a, 13 a facing the outer rolling surfaces 12 a, 12 a, and freely rollable via the cages 14, 14 between both rolling surfaces. The double row balls 15 and 15 accommodated therein and the seals 16 and 16 attached to both ends of the outer member 12 are provided. The small-diameter (front) side end surface 13b of the inner ring 13 is abutted in a butted state to constitute a so-called back-to-back type double row angular ball bearing.

  The seal 16 is composed of a core metal 16a fitted to the cylindrical portion 12b of the outer member 12, and a seal member 16b integrally joined to the core metal 16a by vulcanization adhesion or the like, and made of an elastomer such as nitrile rubber, A pair of radial lips are provided in sliding contact with the outer diameter surface of the inner ring 13. This prevents leakage of grease sealed inside the bearing and prevents foreign matter such as rainwater and dust from entering the bearing from the outside. Although not shown, a seal having a structure other than the seal 16 may be used. That is, a slinger is press-fitted into the outer diameter of the inner ring 13, and an annular seal plate is mounted on the cylindrical portion 12a of the outer member 12 so as to face the slinger, and the seal lip of the seal plate is brought into sliding contact with the slinger. A so-called pack seal may be used.

  Here, the outer member 12 and the inner ring 13 are obtained by annealing a pipe material made of bearing steel such as SUJ2 or carburized steel such as SCr420 or SCM415, and then press working or cold rolling (hereinafter referred to as plastic working). Is formed. Then, SUJ2 is hardened to a surface hardness of 50 to 64 HRC by submerged or induction hardening, and carburized steel is carburized and quenched. Other examples of the material of the outer member 12 and the inner ring 13 include carbon steel such as S50C to S55C, cold rolled steel plate (such as JIS standard SPCC), or carburized steel such as SCM440.

  On the other hand, in the case of cold rolled steel or carbon steel, at least the double row outer rolling surfaces 12a, 12a are formed by induction hardening in the outer member 12, and at least the inner rolling surface 13a is formed by induction hardening in the inner ring 13. The surface hardness is set in the range of 50 to 64 HRC, and the rolling fatigue life is improved. These rolling surfaces 12a and 13a are formed with predetermined dimensions and accuracy by grinding. After that, superfinishing is performed as necessary.

Next, the configuration of the outer member 12 and the inner ring 13 will be described in detail with reference to FIG.
As shown in (a), the outer member 12 is formed by forming a circular projection 17 projecting radially inward from the pipe material, which is a raw material, and a double row on both sides of the annular projection 17. Arc-shaped outer rolling surfaces 12a and 12a are formed, and cylindrical portions 12b and 12b serving as fitting portions of the seal 16 are formed at both ends.

  Here, in order to appropriately secure the shoulder height of the annular convex portion 17 from the outer rolling surface 12a, the inner diameter of the annular convex portion 17 is formed into a flat shape during plastic processing of the outer member 12, and the outer An annular recess 18 is formed by denting the central portion of the side member 12 so that the shoulder portion 19 is filled with the material. Note that both end surfaces where burrs are generated by plastic working are turned after machining. Moreover, a grinding process is given as needed.

  On the other hand, as shown in (b), the inner ring 13 is formed by plastic processing from a pipe material as a raw material, and an arcuate inner rolling surface 13a on the outer periphery, and from the large diameter side of the inner rolling surface 13a in the axial direction An extending shoulder 20 is formed. Here, the shoulder portion 20 becomes a seal land portion of the seal 16, and is ground at the same time as the inner rolling surface 13a after plastic working, and is formed with a predetermined size and accuracy. As with the outer member 12, both end faces where burrs are generated by plastic working are turned after machining. Moreover, a grinding process is given as needed.

  In the present embodiment, the outer member 12 and the inner ring 13 are formed from a pipe material by plastic working, and the cylindrical portion 12b of the outer member 12 serving as a fitting surface between the rolling surfaces 12a and 13a and the seal 16, and Since the shoulder portion 20 of the inner ring 13 serving as the seal land portion of the seal 16 is formed by grinding, the productivity is improved, the yield is good, the cost can be reduced, and it is equivalent to the conventional bearing. Accuracy and sealability can be secured. The outer diameter surface of the outer member 12 that becomes the fitting surface of the knuckle 2 and the hub wheel 1, the inner diameter of the inner ring 13, and the small-diameter side end surface 13b of the inner ring 13 that becomes the butting surface may be formed by grinding. . Thereby, the bearing accuracy equivalent to the conventional forged and machined bearing can be ensured.

  Here, in this embodiment, as shown in FIG. 2, the annular recess 18 of the outer member 12 is filled with a heat-resistant thermoplastic synthetic resin based on PA (polyamide) 11 by injection molding, and the resin band 21 Is formed. The outer diameter of the resin band 21 is formed so as to protrude from the outer diameter of the outer member 12 by 0 to 50 μm. If the amount of protrusion is 0 or less, it is difficult to reliably prevent a decrease in squeeze due to temperature rise, and if the amount of protrusion exceeds 50 μm, the resin band 21 is likely to be peeled when the knuckle 2 is press-fitted. Although the amount of protrusion differs slightly depending on the size of the bearing, etc., it is preferable to set it within a range of 10 to 40 μm in consideration of manufacturing variations.

  Thereby, preload loss and bearing creep can be effectively prevented. That is, due to the difference in linear expansion coefficient between the knuckle 2 and the outer member 12, for example, the fitting shimiro between the knuckle 2 and the outer member 12 will not be reduced or released due to the temperature rise during traveling, Preload loss can be prevented and the bearing preload during assembly can be maintained over a long period of time. Furthermore, it is possible to reliably prevent the outer member 12 from creeping and seizing or inducing a short life.

  Further, in the present embodiment, similarly to the outer member 12, the annular recess 22 extending from the inner peripheral surface of the shoulder portion 20 of the inner ring 13 to the chamfered portion 13c is filled with a heat-resistant thermoplastic synthetic resin made of PA11 by injection molding. A resin band 23 is formed. The resin band 23 is formed so as to protrude from the large-diameter (rear) side end surface 13d of the inner ring 13 in a range of 0 to 50 μm, preferably 10 to 40 μm in consideration of manufacturing variations.

  The bearing preload is applied by sandwiching the large-diameter side end surfaces 13d and 13d of the pair of inner rings 13 and 13 between the shoulder 1a of the hub wheel 1 and the shoulder 9 of the outer joint member 8. In combination with the resin band 21 of the outer member 12, it is possible to reliably prevent the preload from being lost and to retain the initially set bearing preload for a long period of time.

The material of the resin bands 21 and 23 is not limited to the PA 11 described above, and is larger than the linear expansion coefficient (2 to 2.3 × 10 ⁻⁵ / ° C.) of the knuckle 2 made of a light alloy such as an aluminum alloy. A synthetic resin having an expansion coefficient of 8 to 16 × 10 ⁻⁵ / ° C. may be used. For example, PA66 and those obtained by adding reinforcing fibers such as GF (glass fiber) in the range of 10 to 30 wt% to these thermoplastic synthetic resins can be exemplified.

  FIG. 4 shows a change in temperature and a change in bearing preload, that is, a change in the outer member, in a state where only the outer members of the conventional wheel bearing and the wheel bearing according to the present embodiment are press-fitted into an aluminum alloy knuckle. The result of the comparative measurement of the relationship with the dimensional change of the outer rolling surface is shown. As is clear from this figure, in the conventional one, the bearing preload decreases linearly in proportion to the temperature rise. However, in the wheel bearing according to this embodiment, the bearing preload gradually increases up to about 80 ° C. Although it decreases, it can be seen that the predetermined preload amount is maintained thereafter.

  As described above in detail, in this embodiment, the knuckle 2 is formed of a light alloy such as an aluminum alloy, and the linear expansion of the knuckle 2 is performed on the outer periphery of the outer member 12 of the wheel bearing 3 that is press-fitted into the knuckle 2. The resin band 21 having a linear expansion coefficient larger than the coefficient is formed, and the resin band 23 having a linear expansion coefficient larger than at least the linear expansion coefficient of the hub wheel 1 and the outer joint member 8 is also formed at the end of the inner ring 13. Because of the difference in linear expansion coefficient between the knuckle 2 and the wheel bearing 3 when the temperature rises, even if the knuckle 2 thermally expands more than the wheel bearing 3, it is possible to suppress the lowering of the fitting shimiro. Creeping can be prevented, and even if the hub wheel 1 or the outer joint member 8 is thermally expanded, the initially set bearing preload can be prevented from being lowered, and the bearing rigidity can be changed. Ete can be maintained reliably running stability of the vehicle.

  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 generation structure including a hub wheel integrally having a wheel mounting flange at one end and a pair of inner rings press-fitted into the hub wheel. .

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is an enlarged view which shows the wheel bearing of FIG. (A) is a longitudinal cross-sectional view which shows the outer member ring single-piece | unit of FIG. (B) is the longitudinal cross-sectional view which shows an inner ring single-piece | unit as above. It is a graph which shows the result of having comparatively measured the relationship between the temperature change of the conventional wheel bearing and the wheel bearing which concerns on this embodiment, and the change of a bearing preload. It is a longitudinal cross-sectional view which shows the angular contact ball bearing of the structure where the conventional inner and outer ring | wheel was formed by press work.

Explanation of symbols

1 ················· Hub wheel 1a, 9, 19, 20 · · · Knuckle 3 · · · · · · Wheel bearing 4 · · · · · · Wheel mounting flange 4a · · · ··················································································· Serration 7・ ・ ・ ・ ・ ・ ・ ・ Constant velocity universal joint 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer joint member 10 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Stem part 10b ... Male thread 11 ... Fixing nut 12 ... ... External member 12a ... External rolling surface 12b ... ... Cylindrical part 13 ... Inner ring 13a ... Inner rolling surface 13b ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small-diameter side end face 13c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Chamfer 13d ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Large-diameter side end face 14 ... Cage 15 ... Ball 16 ...・ Seal 16a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Core 16b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal member 17 ・ ・ ・ ・ ・ ・ ・ ・················································································ Resin band 50 ... Angular ball bearings 51 ... Outer rings 51a ... ··························································· Outside rolling surface 51d ····························· 52 ... Inner rolling surfaces 52c, 53c ... Fitting part 54 ... Housing 55 ... ············ Shaft member 55a ························································· ··········································································· Bond Agent B ... Brake rotor W ... ········Wheel

Claims (7)

A hub wheel integrally having a wheel mounting flange for mounting a wheel on one end, and a small-diameter step portion extending in the axial direction from the wheel mounting flange via a shoulder; and
An outer joint member of a constant velocity universal joint fitted into the hub wheel via a serration;
A knuckle constituting a suspension device;
A wheel bearing fitted with a predetermined scissors between the knuckle and the small-diameter step portion of the hub wheel,
In the wheel bearing device in which the hub wheel is rotatably supported with respect to the knuckle through the wheel bearing,
The wheel bearing has an annular recess at the center of the outer periphery , protrudes radially inward at the inner periphery, and has an annular protrusion with an inner diameter formed in a flat shape, and double rows on both sides of the annular protrusion . An outer member formed integrally with an arc-shaped outer rolling surface;
A pair of inner races formed with an arcuate inner raceway facing the outer raceway of the double row on the outer periphery, and a shoulder extending in the axial direction from the large diameter side of the inner raceway ,
These inner rings and double row balls accommodated between both rolling surfaces of the outer member,
The pair of inner rings are abutted against each other with their small diameter side end faces but the large diameter side end faces of the inner ring are sandwiched between the shoulder part of the hub ring and the shoulder part of the outer joint member, and a predetermined bearing preload is applied. Back-to-back type double row angular contact ball bearings,
The wheel bearing device, wherein the outer member and the inner ring are formed from a pipe material by plastic working, and a resin band made of a heat-resistant synthetic resin is filled in the annular recess of the outer member by injection molding. .   The wheel bearing device according to claim 1, wherein the knuckle is made of a light alloy, and the linear expansion coefficient of the resin band is set larger than the linear expansion coefficient of the knuckle.   The wheel bearing device according to claim 1 or 2, wherein an outer diameter of the resin band is formed so as to protrude 0 to 50 µm from an outer diameter of the outer ring.   A shoulder portion extending in the axial direction from the large diameter side of the inner raceway surface of the inner ring is formed, and a resin band made of a heat-resistant synthetic resin is formed by injection molding in an annular recess extending from the inner peripheral surface of the shoulder portion to the chamfered portion. The wheel bearing device according to any one of claims 1 to 3, wherein the wheel bearing device is filled.   The wheel bearing device according to claim 4, wherein the resin band is formed to protrude from 0 to 50 μm from the large-diameter side end surface of the inner ring.   The wheel bearing device according to any one of claims 1 to 5, wherein the outer member and the inner ring are formed by cold rolling from a pipe material. The wheel bearing device according to any one of claims 1 to 6, wherein the resin band is made of a polyamide-based synthetic resin, and a linear expansion coefficient thereof is set to 8 to 16 × 10 ^-5 / ° C.

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