JP2008106861A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel having solved the contradictory problems of reduction in the weight and size of the device and its higher rigidity, and having enhanced strength and durability. <P>SOLUTION: This bearing device for a wheel comprises double rows of tapered rollers 9, 22. An inner ring 20 is fixed by swinging and caulking the end of the small diameter step part 13b of a hub wheel 13. The pitch circle diameter PCDi of the inner row of tapered rollers 22 is set larger than the pitch circle diameter PCDo of the outer row of tapered rollers 9. The numbers of the rollers of the double rows of tapered rollers are set to the same value. The roller diameter di of the inner row of tapered rollers 22 is set larger than the roller diameter do of the outer row of tapered rollers 9. The roller length Li of the inner row of tapered rollers 22 is set longer than the roller length Lo of the outer row of tapered rollers 9. Consequently, the rigidity and the life of the bearing can be enhanced, and the weight and size of the bearing can be reduced by effectively utilizing a bearing space. <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. 9 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. 10 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 Filtration diameter is set to be larger in diameter than the roller diameter of the tapered roller rows of the outer side.

  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, and the roller diameter of the inner tapered roller train is set to be larger than the roller diameter of the outer tapered roller train. The service life can be improved and the bearing space can be effectively utilized to reduce the weight and size. Accordingly, it is possible to provide a wheel bearing device that can simultaneously solve the conflicting problems of light weight, compactness, and high rigidity of the device, and that has improved strength and durability.

  Preferably, as in the invention described in claim 2, if the roller length of the inner side tapered roller row is set longer than the roller length of the outer side tapered roller row, the inner side bearing row The basic dynamic load rating of the bearing can be increased and the rigidity and life of the bearing can be further improved.

  Further, as in the invention described in claim 3, if the inner ring is fixed in the axial direction by a caulking portion formed by plastically deforming an end portion of the small diameter step portion radially outward, the weight is reduced. Compactness can be achieved.

  Further, as in the invention described in claim 4, 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 is 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.

  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 diameter of the tapered roller row on the side is the circle on the outer side Because it is set to be larger in diameter than the roller diameter of the roller rows, it is possible to improve the rigidity and life of the bearing, it is possible to reduce the weight and size by effectively utilizing the bearing space. Accordingly, it is possible to provide a wheel bearing device that can simultaneously solve the conflicting problems of light weight, compactness, and high rigidity of the device, and that has improved strength and durability.

  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 row is set to be larger than the pitch circle diameter of the outer side tapered roller row, and the number of rollers in the double row tapered roller row is set to be the same. The roller diameter of the roller train is set larger than the roller diameter of the outer tapered roller train, and the roller length of the inner tapered roller train is larger than the roller length of the outer tapered roller train. It is set long.

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 taper shape in line contact with the tapered rollers 9 and 10, and so-called back-to-back alignment in which the small-diameter (front) side end surfaces 5d and 6d are abutted in a butted state. This constitutes a double-row tapered roller bearing of the type. 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 diameter di of the 10-row tapered rollers is set to be larger than the roller diameter do of the 9-side tapered rollers (di> do). Also, the roller length Lo of the 9 rows of outer side tapered rollers and the roller length Li of the 10 rows of tapered rollers on the inner side are set to be the same (Lo = Li), and the tapered rollers 9 and 10 rows of rollers are set. The number is set to be the same. Thereby, while being able to improve the rigidity and lifetime of a bearing, the bearing apparatus for wheels which achieved the lightweight and compactness by utilizing effectively a bearing space can be provided.

  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. In addition, the roller diameter di of the 10 rows of inner side tapered rollers is set to a larger diameter (di> do) than the roller diameter do of the 9 rows of outer tapered rollers. The roller length Lo of the 9 rows of outer tapered rollers and the roller length Li of the 10 rows of tapered rollers on the inner side are set to be the same (Lo = Li), and the number of the tapered rollers 9 and 10 is the number of rollers. Are set to be the same. Thereby, the rigidity and life of the bearing can be improved while further reducing the weight and size. In addition, the wall thickness t of the inner side inner ring 6 can be increased corresponding to the amount of expansion of the pitch circle diameter PCDi in the 10 rows of inner side tapered rollers, and the inner ring 6 can be increased in accordance with the plastic deformation of the caulking portion 1c. The hoop stress generated on the inner rolling surface 6a and the outer diameter 6e can be suppressed, and the strength and durability of the hub wheel 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. Two inner rings 5 ', 6' formed with inner rolling surfaces 5a, 6a facing the surfaces 4a, 4b, respectively, and cages 7, 8 between both rolling surfaces 4a, 5a and 4b, 6a A plurality of tapered rollers 9, 10 accommodated so as to roll freely.

  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. In addition, the roller diameter di of the 10 rows of inner side tapered rollers is set to a larger diameter (di> do) than the roller diameter do of 9 rows of outer tapered rollers. Then, the roller length Lo of the 9 rows of the tapered rollers on the outer side and the roller length Li of the 10 rows of the tapered rollers on the inner side are set to be the same (Lo = Li). The number is set to be the same. As a result, the rigidity and life of the bearing can be improved while achieving light weight and compactness, and the inner side hub wheel 1 'corresponding to the diameter expansion amount of the pitch circle diameter PCDi in the 10 rows of inner side tapered rollers. The shaft diameter d2 of the small-diameter step portion 1b ′ can be made large (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 diameter di of the 10 rows of the inner side tapered rollers is set to be larger than the roller diameter do of the 9 rows of the outer side tapered rollers (di> do). In addition, the roller length Lo of the 9 rows of the tapered rollers on the outer side and the roller length Li of the 10 rows of the tapered rollers on the inner side are set to be the same (Lo = Li), and the number of the tapered rollers 9 and 10 is the number of rollers. Are set to be the same. As a result, the rigidity and life of the bearing can be improved while achieving light weight and compactness, and the inner side hub wheel 13 ′ is adapted to the amount of expansion of the pitch circle diameter PCDi in the 10 rows of inner side tapered rollers. The shaft diameter d2 of the small-diameter step portion 13b ′ can be formed to a large diameter (d2> d1), and the strength and durability of the hub wheel 13 ′ can be improved.

FIG. 5 is a longitudinal sectional view showing a fifth embodiment of the wheel bearing device according to the present invention. This embodiment basically differs from the first embodiment described above (FIG. 1) only in the configuration of the wheel bearing, and other parts having the same parts or functions have the same reference numerals. Therefore, detailed description is omitted.
This wheel bearing device is for a driven wheel called the second generation, and includes a hub wheel 1 and a wheel bearing 18 fixed to the hub wheel 1. The wheel bearing 18 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 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 wheel bearing 18 has a vehicle body mounting flange 4c integrally on the outer periphery, an outer member 19 having double rows of outer rolling surfaces 4a and 19a formed on the inner periphery, and outer surfaces of these double rows on the outer periphery. Rolls between two inner races 5 and 20 formed with inner rolling surfaces 5a and 20a facing the surfaces 4a and 19a, respectively, and both rolling surfaces 4a and 5a and 19a and 20a via cages 7 and 21 Double row tapered rollers 9 and 22 are accommodated freely. Seals 11 and 12 are attached to the opening of the annular space formed between the outer member 19 and the two inner rings 5 and 20, 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 surface 20a of the inner ring 20 is formed in a tapered shape in line contact with the tapered roller 22, and the so-called back-to-back type double row tapered roller in which the small-diameter (front) side end surfaces 5d and 20d are abutted in a butted state. It constitutes a bearing. A large flange 20b for guiding the tapered roller 22 is formed on the large diameter side of the inner rolling surface 20a, and a small flange 20c for preventing the tapered roller 22 from falling off is formed on the small diameter side.

  The outer member 19 is made 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 19a have a surface hardness in the range of 58 to 64 HRC by induction hardening. It has been cured. Further, the inner ring 20 and the tapered roller 22 are made of a high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching.

  Here, in this embodiment, the pitch circle diameter PCDi of 22 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 diameter di of the 22 rows of tapered rollers is set to be larger than the roller diameter do of the 9 rows of tapered rollers on the outer side (di> do). Further, the roller length Li of the inner side tapered roller 22 row is set to be longer than the roller length Lo of the outer side tapered roller 9 row (Li> Lo), and the tapered roller 9 and 22 row rollers are set. The number is set to be the same. As a result, the basic dynamic load rating of the inner bearing row can be increased and the rigidity and life of the bearing can be improved, and a wheel bearing device that is lightweight and compact by effectively utilizing the bearing space. Can be provided.

  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 20 the same, the small-diameter step portion 1b into which the inner rings 5 and 20 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 inner row of tapered rollers 22 can be improved. The thickness t of the inner ring 20 can be increased, and the hoop stress generated on the inner raceway surface 20a and the outer diameter 20e of the inner ring 20 due to plastic deformation of the caulking portion 1c is suppressed, so that the strength and durability of the inner ring 20 are increased. Can be improved.

  FIG. 6 is a longitudinal sectional view showing a sixth embodiment of the wheel bearing device according to the present invention. This embodiment basically differs from the fifth embodiment described above (FIG. 5) only in the configuration of the hub wheel, and other parts having the same parts or functions have the same reference numerals. Detailed description is omitted.

  This wheel bearing device is for a driven wheel referred to as a third generation, and is composed of an outer member 19, a hub ring 13, and an inner ring 20 press-fitted into a small-diameter step portion 13b of the hub ring 13. And a member 23. The inner ring 20 has a small-diameter side end face 20d that abuts 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.

  Here, in the present embodiment, the pitch circle diameter PCDi of the 22 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. In addition, the roller diameter di of the 22 rows of tapered rollers on the inner side is set larger than the roller diameter do of the 9 rows of tapered rollers on the outer side (di> do). Further, the roller length Li of the inner side tapered roller 22 row is set to be longer than the roller length Lo of the outer side tapered roller 9 row (Li> Lo), and the tapered roller 9 and 22 row rollers are set. The number is set to be the same. As a result, the basic dynamic load rating of the inner bearing row can be increased while further reducing the weight and size, and the rigidity and life of the bearing can be improved. In addition, the wall thickness t of the inner side inner ring 20 can be increased corresponding to the amount of expansion of the pitch circle diameter PCDi in the inner side tapered roller 22 row, and the inner ring 20 is deformed along with the plastic deformation of the caulking portion 1c. The hoop stress generated on the inner rolling surface 20a and the outer diameter 20e can be suppressed, and the strength and durability of the hub wheel 13 and the inner ring 20 can be improved.

  FIG. 7 is a longitudinal sectional view showing a seventh embodiment of the wheel bearing device according to the present invention. This embodiment is basically the same as the fifth embodiment (FIG. 5) 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 24 fixed to the hub wheel 1'. The wheel bearing 24 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 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 24 integrally has a vehicle body mounting flange 4c on the outer periphery, and has an outer member 19 in which double row outer rolling surfaces 4a and 19a are formed on the inner periphery, and outer rolling of these double rows on the outer periphery. Two inner rings 5 ′, 20 ′ formed with inner rolling surfaces 5a, 20a facing the surfaces 4a, 19a, respectively, and cages 7, 21 between both rolling surfaces 4a, 5a and 19a, 20a. A plurality of tapered rollers 9 and 22 accommodated so as to roll freely.

  Here, in the present embodiment, the pitch circle diameter PCDi of the 22 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. In addition, the roller diameter di of the 22 rows of inner side tapered rollers is set to a larger diameter (di> do) than the roller diameter do of the 9 rows of outer tapered rollers. The roller length Li of the 22 rows of inner side 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). The number is set to be the same. As a result, the rigidity and life of the bearing can be improved while achieving light weight and compactness, and the inner side hub wheel 1 'corresponding to the diameter expansion amount of the pitch circle diameter PCDi in the inner side tapered roller 22 row. The shaft diameter d2 of the small-diameter step portion 1b 'can be formed to a large diameter (d2> d1), and the strength and durability of the hub wheel 1' can be improved.

  FIG. 8 is a longitudinal sectional view showing an eighth embodiment of the wheel bearing device according to the present invention. This embodiment basically differs from the above-described seventh embodiment (FIG. 7) only in the configuration of the hub wheel, and other parts having the same parts or functions have 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 19, a hub wheel 13 ′, and an inner ring 20 ′ press-fitted into the small-diameter step portion 13 b ′ of the hub wheel 13 ′. And an inner member 25.

  Here, in the present embodiment, the pitch circle diameter PCDi of the 22 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>), as in the seventh embodiment described above. In addition, the roller diameter di of the 22 rows of inner side tapered rollers is set to be larger than the roller diameter do of the 9 rows of outer tapered rollers (di> do). The roller length Li of the inner side tapered roller 22 row is set to be longer than the roller length Lo of the outer side tapered roller 9 row (Li> Lo), and the tapered roller 9 and 22 row rollers are set. The number is set to be the same. As a result, the basic dynamic load rating of the inner side bearing row can be increased while further reducing the weight and size of the bearing, and the rigidity and life of the bearing can be improved. The shaft diameter d2 of the small-diameter step portion 13b ′ of the inner side hub wheel 13 ′ can be formed to a large diameter (d2> d1) corresponding to the diameter expansion amount of the inner wheel ring 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 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 8th 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, 19 ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer members 4a, 4b, 19a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer rolling surface 4c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・..... Body mounting flange 5, 5 ', 6, 6', 20, 20 '... Inner ring 5a, 6a, 13a, 20a ..... Inner rolling surface 5b, 6b, 20b ........ Daegu 5c, 6c, 20c ... ·········································································································· Small ends 5e, 6d, 20d ... Outer diameter of inner ring on inner side 7, 8, 21 ... Cage 9, 10, 22, ... ······························································································ Seals 14, 17, 23, 25 50, 64 ... hub wheels 50a, 57a, 64a, 65a ... inner rolling surfaces 50b, 63 ... .... Wheel mounting flange 51 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double Row Rolling Bearing 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Constant Velocity Joint 53, 62 ... Outer members 53a, 53b, 62a, 62b ... Outer rolling surfaces 53c, 62c ... ... body mounting flanges 54, 66 ... inner members 55, 67, 68 ...・ ・ ・ ・ ・ ・ ・ Ball 56 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Conical rollers 57, 65 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Inner ring 58 ... outer joint member 58a ... Track groove 59 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse part 60 ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 61 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retaining Ring 64b ・ ・ ・ ・················ Small diameter step 64c ... ········································································· Seals d1, d2・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft diameter di of small diameter step ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Roller diameter doo of inner side tapered roller ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Roller diameter D1 of the outer tapered roller Ball pitch circle diameter D2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ball pitch circle straight 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

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,
Of the double row tapered roller rows, the pitch circle diameter of the inner side tapered roller row is set larger than the pitch circle diameter of the outer side tapered roller row, and the roller diameter of the inner side tapered roller row Is set to be larger in diameter than the roller diameter of the outer tapered roller row.   2. The wheel bearing device according to claim 1, wherein a roller length of the inner side tapered roller row is set longer than a roller length of the outer side tapered roller row. 3.   3. The wheel bearing device according to claim 1, wherein the inner ring is fixed in an axial direction by a caulking portion formed by plastically deforming an end portion of the small-diameter stepped portion radially outward. 4.   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 any one of claims 1 to 3, wherein an inner ring on the inner side is press-fitted.   The wheel bearing device according to any one of claims 1 to 3, 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.

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