JP2008115954A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel improved in strength and durability by simultaneously solving contrary problems of weight and size reduction in the device and the achievement in high rigidity. <P>SOLUTION: This bearing device for the wheel has rows of tapered rollers 9, 10 in a double row, and fixes an inner ring 6 by rocking and caulking the end of a small diameter step 13b of a hub wheel 13. A pitch circle diameter PCDi of the inner side tapered roller 10 row is set in a larger diameter than a pitch circle diameter PCDo of the outer side tapered roller 9 row, and the roller length Li of the inner side tapered roller 10 row is set longer than the roller length Lo of the outer side tapered roller 9 row, and roller diameters di and do of the tapered roller rows of these double rows are set to be the same, and the roller number of the inner side tapered roller 10 row is set larger than the roller number of the outer side tapered roller 9 row. Thus, a basic rated load of the inner side bearing row becomes high, and the rigidity and the service life of a bearing can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

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 is reduced in weight and increased in rigidity.

  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. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  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. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. 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 speed universal joint.

  The wheel bearing device shown in FIG. 5 has a fourth generation structure that is lightweight and compact, and includes a hub wheel 50, a double row rolling bearing 51, and a constant velocity universal joint 52 that are unitized. The double row rolling bearing 51 includes an outer member 53, an inner member 54, and a plurality of balls 55 and tapered rollers 56 accommodated between the two members. 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 outer member 53 integrally has a vehicle body mounting flange 53c attached to a knuckle constituting a suspension device (not shown) on the outer periphery, and double row outer rolling surfaces 53a and 53b are formed on the inner periphery. Here, the diameter of the outer-side outer rolling surface 53a is set to be smaller than the diameter of the inner-side outer rolling surface 53b. On the other hand, the inner member 54 includes a hub wheel 50, an outer joint member 58, which will be described later, integrally formed with the hub wheel 50, and a separate inner ring 57 press-fitted into the outer joint member 58. Yes.

  The hub wheel 50 integrally has a wheel mounting flange 50b for mounting a wheel (not shown) at one end, and the outer side outer rolling surface 53a of the double row outer rolling surfaces 53a and 53b on the outer periphery. The inner race surface 50a is formed directly on the inner ring 57, and the inner race surface 57a on the outer circumference of the inner ring 57 is opposed to the inner race surface 53b on the inner side of the double row outer race surfaces 53a, 53b. Is formed.

  The constant velocity universal joint 52 has an outer joint member 58 composed of a cup-shaped mouth portion 59 and a shoulder portion 60 that forms the bottom of the mouth portion 59, and the outer periphery of the outer joint member 58 has a curved shape. A track groove 58a is formed. The inner ring 57 is press-fitted into the outer diameter of the mouse portion 59 and is fixed in the axial direction by a retaining ring 61.

  A plurality of balls 55 can freely roll between the outer rolling surfaces 53a and 50a of the outer member 53 and the inner member 54, and a plurality of tapered rollers 56 can roll between the inner rolling surfaces 53b and 57a. The pitch circle diameter of the outer 55 rows of the balls 55 and the tapered rollers 56 is set to be smaller than the pitch circle diameter of the inner rows of the tapered rollers 56. As a result, the basic rated load of the inner side bearing row where a larger load than the outer side bearing row is applied is made larger than the basic rated load of the outer side bearing row, and the service life of these two bearing rows is increased. Can be made substantially the same, and a design without waste can be made possible (see, for example, Patent Document 1).

  However, in such a wheel bearing device, since the inner ring 57 is fixed to the mouth portion 59 of the outer joint member 58, it is surely made compact in the axial direction. Not only does the outer diameter itself become large and hinders weight reduction, but it is not preferable due to a design change of peripheral parts such as a knuckle. As a solution to these problems, a wheel bearing device as shown in FIG. 6 is known.

  This wheel bearing device has a vehicle body mounting flange 62c integrally attached to a knuckle (not shown) on the outer periphery, and an outer member having double-row outer rolling surfaces 62a and 62b formed on the inner periphery. 62 and a wheel mounting flange 63 for mounting a wheel (not shown) at one end thereof are integrally formed and opposed to the outer-side outer rolling surface 62a of the double-row outer rolling surfaces 62a and 62b on the outer periphery. The inner raceway 64a, the hub wheel 64 formed with the small diameter step portion 64b extending in the axial direction from the inner raceway surface 64a, and the small diameter step portion 64b of the hub wheel 64, and are fitted on the outer side of the double row. Of the rolling surfaces 62a and 62b, an inner member 66 comprising an inner ring 65 formed with an inner rolling surface 65a facing the inner outer rolling surface 62b, and a double row accommodated between these rolling surfaces. Balls 67, 68 and these It is composed of a double row angular contact ball bearing having a retainer 69, 70 for holding the balls 67, 68 rollably.

  The inner ring 65 is fixed in the axial direction by a caulking portion 64c formed by plastically deforming the small-diameter stepped portion 64b of the hub wheel 64 radially outward. Seals 71 and 72 are attached to the opening portion of the annular space formed between the outer member 62 and the inner member 66, leakage of the lubricating grease sealed inside the bearing, and rainwater entering the bearing from the outside. And dust are prevented from entering.

Here, the pitch circle diameter D1 of the 67 rows of balls on the outer side is set larger than the pitch circle diameter D2 of the 68 rows of balls on the inner side. Along with this, the inner rolling surface 64a of the hub wheel 64 is expanded in diameter than the inner rolling surface 65a of the inner ring 65, and the outer rolling surface 62a on the outer side of the outer member 62 is also rolled on the inner side. The diameter is larger than that of the surface 62b. The outer side balls 67 are accommodated more than the inner side balls 68. As described above, by setting the pitch circle diameters D1 and D2 to D1> D2, the rigidity is improved not only when the vehicle is stationary but also when turning, and the life of the wheel bearing device can be extended. (For example, refer to Patent Document 2).
JP 11-91308 A JP 2004-108449 A

  In such a conventional wheel bearing device, the pitch circle diameter D1 of the outer row of the balls 67 is set larger than the pitch circle diameter D2 of the inner row of the balls 68. The running surface 64 a is larger in diameter than the inner rolling surface 65 a of the inner ring 65. As a result, the rigidity of the outer bearing row can be improved while avoiding an increase in size of the device, and the life of the wheel bearing device can be extended. However, loads applied to the inner and outer bearing rows are different from each other, and the load applied to the inner bearing row is generally larger than the load applied to the outer bearing row. In such a case, in this conventional wheel bearing device, the basic load rating of the inner bearing row is smaller than the basic load rating of the outer bearing row, resulting in a short life.

  The present invention has been made in view of such circumstances, and provides a wheel bearing device that simultaneously solves the conflicting problems of lightweight, compact and high rigidity of the device, and has improved strength and durability. The purpose is to do.

  In order to achieve the object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the knuckle on the outer periphery, and a double row outer rolling surface is formed on the inner periphery. An outer member and a wheel mounting flange for mounting a wheel at one end are integrally formed, a hub wheel having a small-diameter step portion formed on the outer periphery, and press-fitted into the small-diameter step portion of the hub wheel, and An inner member composed of at least one inner ring formed with an inner rolling surface facing the outer rolling surface of the row, and is accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member. In the wheel bearing device provided with the double row tapered roller row, the pitch circle diameter of the inner side tapered roller row of the double row tapered roller row is larger than the pitch circle diameter of the outer side tapered roller row. The diameter of the tapered roller train on the inner side The filter length is set to be longer than the roller length of the outer side tapered roller row, and the number of rollers of the inner side tapered roller row is set to be larger than the number of rollers of the outer side tapered roller row. .

  Thus, in the wheel bearing device of the second or third generation structure provided with the double row tapered roller row, the pitch circle diameter of the inner side tapered roller row out of the double row tapered roller row is the outer side cone. The roller diameter is set to be larger than the pitch circle diameter of the roller train, the roller length of the inner tapered roller train is set to be longer than the roller length of the outer tapered roller train, and the inner tapered roller train The number of rollers is set to be larger than the number of rollers on the outer tapered roller row, so that the conflicting issues of lighter weight, compactness and higher rigidity can be solved simultaneously, and the basic rating of the inner bearing row It is possible to provide a wheel bearing device in which the load is increased and the rigidity and life of the bearing are improved.

  Preferably, as in the invention described in claim 2, if the inner ring is fixed in the axial direction by a caulking portion formed by plastically deforming an end of the small-diameter stepped portion radially outward, the weight is reduced.・ Compact size can be achieved.

  Further, as in the invention described in claim 3, the outer side inner rolling surface is directly formed on the outer periphery of the hub wheel, and the small-diameter step portion extending in the axial direction from the inner rolling surface is formed. If the inner ring on the inner side is press-fitted into the small-diameter step portion through a predetermined scissors, the device can be further reduced in weight and size, and the diameter of the pitch circle diameter in the inner tapered roller train can be increased. Correspondingly, it is possible to increase the thickness of the inner ring on the inner side, and to suppress the hoop stress generated on the inner raceway surface and outer diameter of the inner ring due to plastic deformation of the caulking part, Durability can be improved.

  If the pair of inner rings are press-fitted into the small-diameter step portion of the hub wheel and the inner diameters of these inner rings are set to be the same, the small-diameter step portion of the hub ring is straightened. The inner ring can be made thicker corresponding to the amount of expansion of the pitch circle diameter in the inner tapered roller row. The hoop stress generated on the inner raceway surface and the outer diameter of the inner ring due to plastic deformation of the caulking portion can be suppressed to improve the strength and durability of the inner ring.

  Further, as in the invention described in claim 5, the roller diameter of the tapered roller row on the inner side and the roller diameter of the tapered roller row on the outer side may be set to be the same.

  The wheel bearing device according to the present invention has an outer member integrally formed with a vehicle body mounting flange to be attached to the knuckle on the outer periphery, a double row outer rolling surface formed on the inner periphery, and a wheel at one end. A hub wheel integrally having a wheel mounting flange for mounting a small diameter stepped portion on the outer periphery, and press-fitted into the small diameter stepped portion of the hub wheel, facing the outer circumferential rolling surface of the double row on the outer periphery. An inner member composed of at least one inner ring formed with an inner rolling surface, and a double row conical roller row accommodated so as to roll between the inner member and both rolling surfaces of the outer member. In the wheel bearing device provided, a pitch circle diameter of an inner side tapered roller row of the double row tapered roller rows is set larger than a pitch circle diameter of an outer side tapered roller row, and the inner The roller length of the tapered roller row on the side is the outer side Since the roller length of the tapered roller train is set longer and the number of rollers in the inner tapered roller train is set larger than the number of rollers in the outer tapered roller train, the device is lighter and more compact. In addition, it is possible to provide a wheel bearing device that solves the conflicting problems of increasing rigidity and improving the rigidity and life of the bearing by increasing the basic load rating of the inner bearing row.

  A body mounting flange for mounting to the knuckle on the outer periphery is integrated, an outer member with a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting the wheel on one end is integrated. A hub ring 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 of the hub ring An inner member composed of an inner ring that is press-fitted into a stepped portion and has an inner rolling surface formed on the outer periphery facing the other of the double row outer rolling surfaces, and both rolling of the inner member and the outer member. A double row tapered roller row that is rotatably accommodated between the surfaces, and the inner ring is connected to the hub ring by a caulking portion formed by plastically deforming an end portion of the small diameter step portion radially outward. In the wheel bearing device fixed in the axial direction, the inner of the double row tapered roller row The pitch circle diameter of the tapered roller train is set to be larger than the pitch circle diameter of the outer tapered roller train, and the roller length of the inner tapered roller train is the roller of the outer tapered roller train. The roller diameters of the double row tapered roller rows are the same, and the number of rollers in the inner side tapered roller row is set to be larger than the number of rollers in the outer side tapered roller row. Yes.

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.
This wheel bearing device is for a driven wheel called the second generation, and includes a hub wheel 1 and a wheel bearing 2 fixed to the hub wheel 1. The hub wheel 1 integrally has a wheel mounting flange 3 for mounting a wheel (not shown) at one end portion on the outer side, and a small-diameter step portion extending from the wheel mounting flange 3 in the axial direction via a shoulder portion 1a. 1b is formed. Hub bolts 3a are planted on the wheel mounting flange 3 at equal intervals in the circumferential direction.

  The wheel bearing 2 is press-fitted into the small-diameter step portion 1b through a predetermined shimiro while being abutted against the shoulder portion 1a of the hub wheel 1, and is formed by plastically deforming the end portion of the small-diameter step portion 1b. It is fixed in the axial direction by the fastening portion 1c. The hub wheel 1 is formed 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 1a to the small diameter step portion 1b. It has been cured. The caulking portion 1c is kept in the surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 3, and the fretting resistance of the small-diameter step portion 1b that becomes the fitting portion of the wheel bearing 2 is improved. The plastic working of the caulking portion 1c can be smoothly performed while preventing generation of minute cracks and the like.

  The wheel bearing 2 integrally has a vehicle body mounting flange 4c to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and double row outer rolling surfaces 4a and 4b are formed on the inner periphery. The outer member 4, two inner races 5 and 6 each having outer circumferential surfaces 5a and 6a opposed to the outer circumferential rolling surfaces 4a and 4b in the double row, and both rolling surfaces 4a and 5a. And 4b and 6a are provided with double row tapered rollers 9 and 10 which are accommodated so as to be rollable via cages 7 and 8, respectively. Seals 11 and 12 are attached to the opening portion of the annular space formed between the outer member 4 and the two inner rings 5 and 6, leakage of grease sealed inside the bearing to the outside, and rainwater from the outside And dust are prevented from entering the bearing.

  The inner rolling surfaces 5a and 6a of the inner rings 5 and 6 are formed in a tapered shape in line contact with the tapered rollers 9 and 10, and the so-called back-to-back alignment, in which the small-diameter side (front) end surfaces 5d and 6d are abutted in a butted state. A double-row tapered roller bearing of the type is constructed. And the large flanges 5b and 6b for guiding the tapered rollers 9 and 10 to the large diameter side of the inner rolling surfaces 5a and 6a, and the small flange 5c for preventing the tapered rollers 9 and 10 from falling off on the small diameter side, 6c is formed.

  The outer member 4 is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the double row outer rolling surfaces 4a and 4b have a surface hardness in the range of 58 to 64HRC by induction hardening. It has been cured. Further, the inner rings 5 and 6 and the tapered rollers 9 and 10 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching.

  Here, in this embodiment, the pitch circle diameter PCDi of 10 rows of inner side tapered rollers is set to a larger diameter (PCDi> PCDo) than the pitch circle diameter PCDo of 9 rows of outer tapered rollers, and the inner side The roller length Li of the 10 rows of tapered rollers is set to be longer than the roller length Lo of the 9 rows of tapered rollers on the outer side (Li> Lo). Further, the roller diameter di of the 10 rows of the inner side tapered rollers and the roller diameter do of the 9 rows of tapered rollers on the outer side are set to be the same (di = do), and the number of rollers Zi of the 10 rows of tapered rollers on the inner side is set. It is set to be larger than the number of rollers Zo in the 9 rows of tapered rollers on the outer side (Zi> Zo). As a result, it is possible to provide a wheel bearing device that is lighter and more compact and has a higher basic rated load on the inner bearing row and improved bearing rigidity and life.

  Further, since the degree of freedom in design increases, even if there is a difference in pitch circle diameters PCDo and PCDi, by making the inner diameters of the inner rings 5 and 6 the same, the small-diameter step portion 1b to which the inner rings 5 and 6 are fitted can be pivoted. The inner ring can be formed into a straight shaft having a diameter d1 and the workability of the hub ring 1 can be improved, and the inner ring on the inner side corresponding to the diameter expansion amount of the pitch circle diameter PCDi in the ten rows of inner tapered rollers. The thickness t of the inner ring 6 can be increased, and the hoop stress generated on the inner raceway surface 6a and the outer diameter 6e of the inner ring 6 due to the plastic deformation of the caulking portion 1c can be suppressed to increase the strength and durability of the inner ring 6. Can be improved.

  FIG. 2 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention. This embodiment basically differs from the above-described embodiment only in the configuration of the hub wheel, and other parts having the same parts or the same functions are denoted by the same reference numerals and detailed description thereof is omitted. .

  This wheel bearing device is for a driven wheel called the third generation, and includes an outer member 4, a hub ring 13, and an inner ring 6 press-fitted into the small-diameter step portion 13 b of the hub ring 13. And a member 14. The hub wheel 13 is formed with an outer-side inner rolling surface 13a facing the outer-side outer rolling surface 4a and a small-diameter step portion 13b extending in the axial direction from the inner-rolling surface 13a. The inner ring 6 has a small-diameter end face 6d abutted against the shoulder 13c of the hub wheel 13 in abutting state, is press-fitted into the small-diameter step part 13b via a predetermined shimiro, and is fixed in the axial direction by the crimping part 1c. Yes.

  Seals 15 and 12 are attached to the opening portion of the annular space formed between the outer member 4 and the hub ring 13 and the inner ring 6, leakage of grease sealed inside the bearing to the outside, and rainwater from the outside. And dust are prevented from entering the bearing. The hub wheel 13 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the seal land portion 3b in which the seal 15 is in sliding contact to the inner rolling surface 13a and the small diameter step portion 13b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening.

  Here, in the present embodiment, the pitch circle diameter PCDi of the 10 rows of tapered rollers on the inner side is larger than the pitch circle diameter PCDo of the 9 rows of tapered rollers on the outer side (PCDi> PCDo), as in the above-described embodiment. At the same time, the roller length Li of the 10 rows of inner side tapered rollers is set longer than the roller length Lo of 9 rows of outer tapered rollers (Li> Lo). Further, the roller diameter di of the 10 rows of the inner side tapered rollers and the roller diameter do of the 9 rows of the outer side tapered rollers are set to be the same (di = do), and the inner side cone is changed due to the difference in pitch circle diameter. The number of rollers Zi in the 10 rows of rollers is set to be larger than the number of rollers Zo in the 9 rows of outer tapered rollers (Zi> Zo). As a result, the rigidity and life of the bearing can be improved while further reducing the weight and size, and the inner ring 6 on the inner side corresponding to the diameter expansion amount of the pitch circle diameter PCDi in the ten rows of inner tapered rollers. The wall thickness t can be increased. Therefore, the hoop stress generated on the inner raceway surface 6a and the outer diameter 6e of the inner ring 6 due to the plastic deformation of the caulking portion 1c can be suppressed, and the strength and durability of the hub ring 13 and the inner ring 6 can be improved.

  FIG. 3 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention. This embodiment is basically different from the first embodiment (FIG. 1) described above except that the configuration of the hub wheel and the wheel bearing is partially different, and other parts having the same parts or the same functions. Are denoted by the same reference numerals and detailed description thereof is omitted.

  This wheel bearing device is for a driven wheel called a second generation, and includes a hub wheel 1 'and a wheel bearing 16 fixed to the hub wheel 1'. The wheel bearing 16 is press-fitted into the small diameter step portion 1b ′ through a predetermined shimiro while being in contact with the shoulder portion 1a of the hub wheel 1 ′, and the end portion of the small diameter step portion 1b ′ is plastically deformed. It is fixed in the axial direction by the formed caulking portion 1c.

  The wheel bearing 16 has a vehicle body mounting flange 4c integrally on the outer periphery, an outer member 4 having double rows of outer rolling surfaces 4a and 4b formed on the inner periphery, and outer rolling of these double rows on the outer periphery. Inner rolling surfaces 5a, 6a facing the surfaces 4a, 4b are formed, and two inner rings 5 ', 6' set to be thinner than the inner rings 5, 6 of the first embodiment described above, and both rolling Between the surfaces 4a, 5a and 4b, 6a, there are provided a plurality of tapered rollers 9, 10 which are accommodated so as to be able to roll via retainers 7, 8.

  Here, in the present embodiment, the pitch circle diameter PCDi of the 10 rows of the inner side tapered rollers is larger than the pitch circle diameter PCDo of the 9 rows of the outer side tapered rollers (PCDi> PCDo) as in the above-described embodiment. At the same time, the roller length Li of the 10 rows of inner side tapered rollers is set longer than the roller length Lo of 9 rows of outer tapered rollers (Li> Lo). Further, the roller diameter di of the 10 rows of the inner side tapered rollers and the roller diameter do of the 9 rows of the outer side tapered rollers are set to be the same (di = do), and the inner side cone is changed due to the difference in pitch circle diameter. The number of rollers Zi in the 10 rows of rollers is set to be larger than the number of rollers Zo in the 9 rows of outer tapered rollers (Zi> Zo). As a result, the rigidity and life of the bearing can be improved while achieving light weight and compactness, and the small diameter step in the hub wheel 1 ′ can be adapted to the diameter expansion amount of the pitch circle diameter PCDi in the 10 rows of tapered rollers on the inner side. The shaft diameter d2 of the portion 1b ′ can be formed to have a large diameter (d2> d1 (FIG. 1)), and the strength and durability of the hub wheel 1 ′ can be improved.

  FIG. 4 is a longitudinal sectional view showing a fourth embodiment of the wheel bearing device according to the present invention. This embodiment basically differs from the third embodiment described above (FIG. 3) only in the configuration of the hub wheel, and other parts having the same parts or the same functions are denoted by the same reference numerals. Detailed description is omitted.

  This wheel bearing device is for a driven wheel referred to as a third generation, and includes an outer member 4, a hub wheel 13 ', and an inner ring 6' press-fitted into the small-diameter step portion 13b 'of the hub wheel 13'. And an inner member 17 made of

  The hub wheel 13 ′ is formed of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the seal land portion 3 b slidably contacting the seal 15 to the inner rolling surface 13 a and the small diameter step portion 13 b ′. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening.

  In this embodiment, as in the third embodiment described above, the pitch circle diameter PCDi of the 10 inner tapered roller rows is larger than the pitch circle diameter PCDo of the 9 outer tapered roller rows (PCDi>). In addition, the roller length Li of the inner side tapered roller 10 row is set to be longer than the roller length Lo of the outer side tapered roller 9 row (Li> Lo). Further, the roller diameter di of the 10 rows of the inner side tapered rollers and the roller diameter do of the 9 rows of the outer side tapered rollers are set to be the same (di = do), and the inner side cone is changed due to the difference in pitch circle diameter. The number of rollers Zi in the 10 rows of rollers is set to be larger than the number of rollers Zo in the 9 rows of outer tapered rollers (Zi> Zo). As a result, the rigidity and life of the bearing can be improved while further reducing the weight and size, and the small diameter of the hub wheel 13 ′ corresponding to the diameter expansion amount of the pitch circle diameter PCDi in the 10 rows of tapered rollers on the inner side. The shaft diameter d2 of the step portion 13b ′ can be formed to a large diameter (d2> d1 (FIG. 2)), and the strength and durability of the hub wheel 13 ′ 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 having a second or third generation structure regardless of whether it is for driving wheels or driven wheels.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present 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 the conventional wheel bearing apparatus. It is a longitudinal cross-sectional view which shows the other conventional wheel bearing apparatus.

Explanation of symbols

1, 1 ', 13, 13' ......... Hub wheel 1a, 13c ......... Shoulder 1b, 1b ' , 13b, 13b '·········· Small diameter step 1c ··············· Wheel Bearing 3 ·························· Wheel Mounting Flange 3a ..... hub bolt 3b ..... seal land 4 ... · · · · · · · · · Outer members 4a, 4b · · · · · · outer rolling surface 4c ... ..... Body mounting flange 5, 6, 5 ', 6' ..... Inner ring 5a 6a, 13a ..... Inner rolling surfaces 5b, 6b ....... ···········································································································・ ・ ・ ・ ・ ・ ・ ・ Outer diameter of inner ring on inner side 7, 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 9, 10, ······························································································· Seals 14, 17・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner members 50 and 64 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheels 50a, 57a, 64a, 65a ... ..Inner rolling surface 50b, 63 ......... Wheel mounting flange 51 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double-row rolling bearings 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Constant velocity universal joints 53 , 62 ... Outer members 53a, 53b, 62a, 62b ... Outer rolling surfaces 53c, 62c ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Body mounting flanges 54, 66 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner members 55, 67, 68 ・ ・ ・ ・ ・ ・... 56 Ball ... tapered rollers 57, 65 ... .... Inner ring 58 ... Outer joint member 58a ...・ Track groove 59 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse part 60 ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 61 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retaining Ring 64b ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small-diameter stepped portion 64c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Clamping portion 69, 70 ・ ・ ・····································································· Seals d1, d2・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft diameter di of small diameter step ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Roller diameter doo of inner side tapered roller ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Roller diameter D1 of outer side tapered roller ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer side Pitch circle diameter D2 of the ball of the inner ball P ............ Pitch circle of the ball on the inner side Diameter Li ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner side tapered roller length Lo ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・······ PCDi roller length of outer tapered roller ··································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pitch circle diameter t of outer side tapered roller ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Inner ring wall thickness Zi ................. ... Number of outer tapered rollers

Claims (5)

An outer member integrally having a vehicle body mounting flange to be attached to the knuckle 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, a small diameter stepped portion formed on the outer periphery, and press-fitted into the small diameter stepped portion of the hub wheel, and the double row outer rolling on the outer periphery An inner member composed of at least one inner ring formed with an inner rolling surface facing the surface;
In the wheel bearing device including the inner member and a double row tapered roller row accommodated in a freely rolling manner between both rolling surfaces of the outer member,
The pitch circle diameter of the inner side tapered roller row of the double row tapered roller row is set larger than the pitch circle diameter of the outer side tapered roller row, and the roller length of the inner side tapered roller row is set. Is set longer than the roller length of the outer side tapered roller row, and the number of rollers of the inner side tapered roller row is set to be larger than the number of rollers of the outer side tapered roller row. A wheel bearing device that is characterized.   The wheel bearing device according to claim 1, wherein the inner ring is fixed in the axial direction by a caulking portion formed by plastically deforming an end portion of the small-diameter stepped portion radially outward.   An outer side inner rolling surface is directly formed on the outer periphery of the hub wheel, and the small-diameter step portion extending in the axial direction from the inner rolling surface is formed. The wheel bearing device according to claim 1 or 2, wherein an inner ring on the inner side is press-fitted.   The wheel bearing device according to claim 1 or 2, wherein a pair of inner rings are press-fitted into the small-diameter step portion of the hub ring, and the inner diameters of these inner rings are set to be the same.   The wheel bearing device according to any one of claims 1 to 4, wherein a roller diameter of the inner side tapered roller train and a roller diameter of the outer side tapered roller train are set to be the same.

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