JP4032999B2 - Rolling bearing unit for wheel support - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an improvement in a rolling bearing unit for supporting a wheel that supports a vehicle wheel and a rotating rotor for braking such as a rotor or a drum.
[0002]
[Prior art]
  A wheel 1 constituting a wheel of an automobile and a rotor 2 as a braking rotating body constituting a disc brake as a braking device rotate to a knuckle 3 constituting a suspension device, for example, by a structure as shown in FIG. Supports freely. That is, the outer ring 6 constituting the wheel bearing rolling bearing unit 5 which is the subject of the present invention is fixed to the circular support hole 4 portion formed in the knuckle 3 by a plurality of bolts 7. On the other hand, the wheel 1 and the rotor 2 are connected to the hub 8 which is the inner ring described in the claims and which is the rotating side race ring, which constitutes the wheel support rolling bearing unit 5, and a plurality of studs 9 and nuts. 10 and fixedly coupled.
[0003]
  Double row outer ring raceways 11a and 11b are formed on the inner peripheral surface of the outer ring 6, and a fixed flange 12 is formed on the outer peripheral surface. Such an outer ring 6 is fixed to the knuckle 3 by connecting the fixed flange 12 to the knuckle 3 with the bolts 7.
[0004]
  On the other hand, the hub 8 is formed by combining the hub body 13 and the inner ring 14. Of these, a part of the outer peripheral surface of the hub body 13 is the outer end opening of the outer ring 6 (outside with respect to the axial direction means a portion that is outside in the width direction when assembled to the automobile, and is shown in FIGS. On the other hand, the right side of FIGS. 1, 3, and 5-8, which is the center side in the width direction in the assembled state to the automobile, is said to be inward with respect to the axial direction. The rotation side flange 15 which is the flange described in the claim is formed in the part. The wheel 1 and the rotor 2 are coupled and fixed to one side surface (outer surface in the illustrated example) of the rotation side flange 15 by the studs 9 and the nuts 10.
[0005]
  Further, on the outer peripheral surface of the intermediate portion of the hub main body 13, a first inner ring raceway 17 is connected to the hub main body 13 at a portion of the double row outer ring raceways 11 a and 11 b facing the outer outer raceway 11 a. Directly formed. Further, the hub 8 is configured by externally fixing the inner ring 14 to a small-diameter step portion 18 formed on the outer peripheral surface of the inner end portion of the hub body 13. The second inner ring raceway 19 formed on the outer peripheral surface of the inner ring 14 is opposed to the inner outer ring raceway 11b of the double row outer ring raceways 11a and 11b.
[0006]
  Between these outer ring raceways 11a and 11b and the first and second inner ring raceways 17 and 19, a plurality of balls 20 and 20 each of which is a rolling element are held by cages 21 and 21, respectively. It is provided so that it can roll freely. With this configuration, a double-row angular type ball bearing which is a rear combination is configured, and the hub 8 is rotatably supported on the inner side of the outer ring 6 and can support a radial load and a thrust load. Seal rings 22a and 22b are provided between the inner peripheral surface of both ends of the outer ring 6, the outer peripheral surface of the intermediate part of the hub body 13 and the outer peripheral surface of the inner end of the inner ring 14, respectively. The internal space provided with 20, 20 is blocked from the outside. Further, since the illustrated example is a wheel support rolling bearing unit 5 for driving wheels (the rear wheels of FR and RR vehicles, the front wheels of FF vehicles, and all wheels of 4WD vehicles), In addition, a spline hole 23 is formed. The spline shaft 25 of the constant velocity joint 24 is inserted into the spline hole 23.
[0007]
  When the wheel support rolling bearing unit 5 as described above is used, as shown in FIG. 8, the outer ring 6 is fixed to the knuckle 3, and the wheel 1 in which a tire (not shown) is combined with the rotation side flange 15 of the hub body 13. And the rotor 2 is fixed. A brake disc brake is configured by combining the rotor 2 and the support and caliper (not shown) fixed to the knuckle 3. At the time of braking, a pair of pads provided with the rotor 2 interposed therebetween are pressed against both side surfaces, which are friction surfaces for braking of the rotor 2. In this specification, the braking friction surface means both axial surfaces of the rotor when the braking rotator is a rotor, and this drum when the braking rotator is a drum. Say the inner surface.
[0008]
  Further, it has been conventionally known that the main part of the hub body 13 constituting the hub 8 of the rolling bearing unit 5 for supporting the wheel as described above is hardened by hardening, for example, as described in Patent Documents 1 and 2. ing. In the case of the rolling bearing unit for supporting a wheel described in each of these Patent Documents 1 and 2, the portion of the hub body that is hung on the inner side base portion or the small diameter step portion of the rotation side flange is quenched and hardened. And while improving the intensity | strength of the said rotation flange with respect to the moment load added at the time of driving | running | working, the improvement of the abrasion resistance of each outer peripheral surface of the said hub main body and the rolling fatigue life is aimed at.
[0009]
  On the other hand, it is known that vibration with unpleasant noise, called judder, is often generated when a vehicle is braked. There are various known causes of such vibration, such as uneven friction between the side surface of the rotor 2 and the lining of the pad. However, it is known that the vibration of the rotor 2 is also a major cause. It has been. That is, the side surface of the rotor 2 should be perpendicular to the rotation center of the rotor 2, but it is difficult to make it completely perpendicular due to inevitable manufacturing errors. As a result, it is inevitable that the side surface of the rotor 2 swings in the direction of the rotation axis (left-right direction in FIG. 8), although it is somewhat, when the automobile is running. When such deflection (the amount of displacement in the left-right direction in FIG. 8) increases, the judder occurs when the lining of a pair of pads is pressed against both side surfaces of the rotor 2 for braking. Further, when the drum constituting the drum brake is fixed to the side surface of the rotation side flange 15, the shoe is attached to the inner peripheral surface unless the inner peripheral surface of the drum is completely parallel to the rotation center of the drum. When pressed, vibration like judder is generated.
[0010]
  In order to suppress judder caused by such a cause, it is important to suppress (reduce) the axial runout (axial runout) of the side surface of the rotor 2 or the radial runout of the inner peripheral surface of the drum. Become. In order to suppress this deflection, it is important to improve the perpendicularity of the mounting surface 26 (the surface on which the rotor 2 is mounted) of the rotation side flange 15 with respect to the rotation center of the hub body 13. For this purpose, as described in Patent Documents 3 and 4, etc., after assembling the constituent members of the wheel bearing rolling bearing unit, the mounting surface of the rotation side flange is machined to process this mounting surface. Techniques for improving the perpendicularity of the are known.
[0011]
[Patent Document 1]
  JP 2002-21858 A
[Patent Document 2]
  JP 2002-87008 A
[Patent Document 3]
  US Pat. No. 6,071,180
[Patent Document 4]
  US Pat. No. 6,364,426
[0012]
[Problems to be solved by the invention]
  If the perpendicularity of the mounting surface 26 is improved by techniques such as those described in Patent Documents 3 and 4, it is considered that the generation of the judder can be considerably reduced. However, even if the perpendicularity of the mounting surface 26 is improved by techniques such as those described in Patent Documents 3 and 4, etc., the wheel 1 and the rotor 2 are supported and fixed to the mounting surface 26. When the mounting surface 26 is distorted, the side surface of the rotor 2 is not necessarily sufficiently prevented from swinging in the axial direction, and the effect of preventing the occurrence of judder is impaired.
[0013]
  In order to prevent the mounting surface 26 from being distorted as the wheel 1 and the rotor 2 are supported and fixed to the mounting surface 26, the hardness of the rotary flange 15 provided with the mounting surface 26 is increased. Can be considered. Techniques for quenching and hardening a part of the rotation side flange 15 (inner side base end) are also described in Patent Documents 1 and 2, but the prior art described in each of these Patent Documents 1 and 2 However, it does not take into consideration the deformation prevention of the portion where the stress is applied when the wheel 1 and the rotor 2 are supported and fixed to the mounting surface 26, only by quenching and hardening the inner side base end portion of the rotation side flange 15. .
[0014]
  On the other hand, if the mounting surface 26 is quenched and hardened in order to prevent deformation of a portion where stress is applied when the wheel 1 and the rotor 2 are simply supported and fixed to the mounting surface 26, the toughness of the rotating flange 15 is ensured. It becomes difficult to do. This is because when the mounting surface 26 is quenched and hardened, wear caused by sliding between the hardened layer formed on the mounting surface 26 and the seal ring 22a is prevented, or the fatigue strength against bending moment is improved. This is because the hardened and hardened layer formed at the proximal end portion of the inner side surface of the rotation side flange 15 as an object is adjacent or continuous. As is well known, the hardened hardened layer has lower toughness than cracked (raw) parts, and crack damage is likely to occur. Therefore, it is not preferable to form a hardened hardened layer on both the inner and outer side surfaces of the rotating flange 15.
  The wheel bearing rolling bearing unit of the present invention has been invented in view of such circumstances.
[0015]
[Means for Solving the Problems]
  The wheel-supporting rolling bearing unit of the present invention includes an inner ring having a double-row inner ring raceway on the outer peripheral surface and a double-row outer ring on the inner peripheral surface, similarly to the conventionally known wheel-supporting rolling bearing unit. An outer ring having a track and arranged concentrically with the inner ring around the inner ring, and a plurality of rolling elements provided in a freely rotatable manner between the inner ring track and the outer ring track. Prepare.
  And, it is used in a state in which the braking rotator and the wheel are coupled and fixed to the side surface of the flange formed on the outer peripheral surface of the rotating raceway rotating during use among the inner ring and the outer ring by a screw rod member. The
  In particular, in the rolling bearing unit for supporting a wheel according to the present invention, the portion of the flange located around the screw rod member and pressed by a part of the wheel as the screw rod member is tightened. And of the overlapping parts with respect to the axial direction of this screw rod memberIn a position that surrounds the entire circumference of this screw rod memberThe hardened and hardened layer is formed.
[0016]
[Action]
  In the case of the rolling bearing unit for supporting a wheel according to the present invention configured as described above, a portion that is pressed by a part of the wheel as the screw rod member is tightened and a portion that overlaps with the axial direction of the screw rod member. homeIn a position that surrounds the entire circumference of this screw rod memberBased on the presence of the formed hardened hardened layer, the rotation side flange is less likely to be distorted as the screw rod member is tightened. For this reason, it is difficult for vibration to occur on the surface to be braked of the braking rotating body supported and fixed to the rotation side flange, and it is possible to effectively prevent the occurrence of judder during braking.
  In addition, since the hardened hardened layer is formed on the inner surface side of the rotation side flange, the toughness of the rotation side flange is ensured, and cracking damage to the rotation side bearing ring including the rotation side flange hardly occurs. Can be left.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
  1 and 2Reference examples related to the present inventionThe 1st example of is shown. A plurality of mounting holes 16 (typically 4 to 6 in the case of a passenger car) are provided at equal intervals in the circumferential direction in a part of the rotation side flange 15 provided near the outer end of the outer peripheral surface of the hub body 13. Forming. Then, in each of the mounting holes 16, a portion near the proximal end of the intermediate portion of each stud 9 that is a screw rod member is fitted and fixed. Each of these studs 9 is formed with an outward flange-shaped flange portion 27 at the base end portion, a serration portion 28 at a portion near the base end portion of the intermediate portion, and a male screw portion 29 at the intermediate portion or the tip portion. Each such stud 9 is inserted into each mounting hole 16 from the inside to the outside of the rotation side flange 15 with the male screw portion 29 first, and the serration portion 28 is press-fitted into the mounting hole 16. In a state where the flange portion 27 is in contact with the inner surface of the rotation side flange 15, the rotation portion 15 is fixed to the rotation side flange 15 while preventing rotation.
[0018]
  Reference exampleIn this case, a hardened and hardened layer 30 is formed over the entire circumference by induction hardening in a portion near the inner diameter of the inner surface of the rotary flange 15. The outer diameter D of the quenched hardened layer 30₃₀Is sufficiently larger than the outer diameter of the quenched and hardened layer in the structure described in Patent Documents 1 and 2 described above. As will be described later, a load applied to the rotation-side flange 15 as the nut 10 is tightened can be supported by the quench hardened layer 30. For thisReference exampleIn the case of₃₀The diameter R of the inscribed circle of each conical concave surface 35 formed on the wheel 1₃₅Larger than (D₃₀> R₃₅)is doing. MoreReference exampleIn the case of₃₀The diameter R of the inscribed circle of the counterbore portion 31 formed concentrically with the mounting holes 16 at a plurality of locations on the inner surface of the rotary flange 15 in order to accommodate the flange portion 27₃₁Larger than (D₃₀> R₃₁)is doing. In addition, although the thickness (depth from the inner surface) of the quench hardening layer 30 is regulated from a surface that prevents the deformation of the rotation side flange 15 while ensuring the toughness of the rotation side flange 15, it is generally used. In the case of a rolling bearing unit for supporting a wheel for a passenger car, the length is about 1 to 4 mm.
[0019]
  The quench hardened layer 30 is hardened and hardened simultaneously with the portion of the rotating side flange 15 that is hung on the inner surface base portion or the small diameter step portion. That is,Reference exampleAlso in this case, the inner side base portion, the first inner ring raceway 17 portion, and the small-diameter step portion 18 (see FIG. 8) with which the tip edge of the seal lip of the seal ring 22a is slidably contacted are prevented from wearing or rolling life is ensured. Hardened and hardened from the surface. Heat treatment (quenching and tempering treatment) for forming the hardened and hardened layer 30 is performed simultaneously with these portions.Reference exampleIn this case, since the hardened hardening layer 30 has a symmetrical shape with respect to the circumferential direction, the heat treatment for quenching rotates the hub body 13 around its central axis while fixing the heating coil. It can be easily done. In addition, it is possible to prevent the occurrence of uneven baking based on the unevenness of the distance between the heating coil and the surface of the hub body 13 to be quenched, and a high-quality quenched and hardened layer 30 can be obtained.
[0020]
  Further, the wheel 1 and the rotor 2 are coupled and fixed to the rotation side flange 15 by the studs 9 fixed to the rotation side flange 15 as described above. Of these, the rotor 2 is externally fitted to a cylindrical surface portion 32 formed on the outer peripheral surface of the hub main body 13 and adjacent to the outside of the rotation side flange 15 for positioning in the radial direction. In this state, the studs 9 are inserted through the through holes 33 formed in the rotor 2.
[0021]
  The wheel 1 is made by pressing a steel plate, casting a light alloy, or forging a light alloy, and is aligned with the studs 9. A through hole 34 is formed in each portion. The peripheral portion of each through hole 34 on the inner surface of the wheel 1 is formed by bending the steel plate or by forming a concave portion such as a stealer in a part of the light alloy, thereby forming a mortar-shaped cone. A concave surface 35 is formed. These conical concave surfaces 35 are provided for the purpose of facilitating the work of inserting the studs 9 into the through holes 34 when the wheel 1 is attached to the rotation side flange 15, and the studs 9. In order to prevent loosening of the nut 10 that is screwed into and further tightened, it is provided to provide a spring action.
[0022]
  In order to couple and fix the wheel 1 as described above to the rotation side flange 15, nuts inserted into the through holes 34 of the studs 9 and screwed into the male threaded portions 29 of the studs 9. Tighten 10 As a result of the tightening of the nut 10, the peripheral edge portion of each conical concave surface 35 abuts on the outer surface of the inner diameter portion of the rotor 2 on the inner surface of the wheel 1, and as indicated by arrows α and α in FIG. The part is pressed strongly inward in the axial direction. A chain line γ in FIG. 2 represents a portion where the peripheral portion of each conical concave surface 35 presses the outer surface of the rotation side flange 15 (inner peripheral edge in the range) as indicated by arrows α, α. Yes. On the other hand, the flange 27 strongly presses a part of the rotation side flange 15 outward in the axial direction as indicated by an arrow β in FIG. The position where the flange portion 27 presses a part of the rotation side flange 15 is the peripheral portion of the mounting hole 16, but the arrow β is described at the center where the force based on the flange portion 17 acts. ing.
[0023]
  Due to the force acting in the opposite direction indicated by the arrows α and β, a force in the direction of bending the peripheral portion acts on the peripheral portion of each mounting hole 16 in a part of the rotation side flange 15. When the peripheral portion of each mounting hole 16 of the rotation side flange 15 is deformed by this force, both side surfaces of the rotor 2 coupled and fixed to the rotation side flange 15 are swung in the axial direction as the hub body 13 rotates. The judder as described above is generated. On the contraryReference exampleIn this case, a part of the force acting in the direction indicated by the arrows α and α from the peripheral portion of each conical concave surface 35 is supported by the hardened hardened layer 30 portion. Since the portion where the quench hardened layer 30 is formed has high hardness and is not easily deformed by an external force, most of the forces acting in the directions indicated by the arrows α and α are the hardened hard layer 30 portion. It will be supported by. That is,This reference ExampleIn this case, the hardened hardened layer is formed on the portion where the force is applied in the directions of the arrows α and α and the portion overlapping the axial direction of each stud 9 (the portion closer to the inner diameter of the rotation side flange 15). 30 is formed.
[0024]
  Since it is configured in this manner, the remaining part of the force acting in the directions of the arrows α and α, excluding a part facing the hardened hardening layer 30, does not form a hardened hardening layer (raw Act on relatively soft parts. When a force acts only on this soft part, this soft part is deformed and leads to the generation of the judder.Reference exampleIn this case, not only the soft portion but also the quench-hardened layer 30 portion is simultaneously applied with force. And the force which acts on the said soft part is reduced when this quenching hardening layer 30 part stretches with respect to the said force, and it prevents that this soft part deform | transforms. As a result, deformation of the peripheral portion of each mounting hole 16 in the rotation side flange 15 is suppressed, and the occurrence of judder can be prevented.
[0025]
  Further, the hardened and hardened layer 30 is provided on the same side as the hardened and hardened layer provided on the inner surface base of the rotating side flange 15 in order to prevent wear and secure bending rigidity. Therefore, a sufficient (raw) portion that is not quenched and hardened can be left in the rotation side flange 15. As a result, sufficient toughness of the rotating flange 15 can be ensured, and even when an impact load is applied to the hub body 13, it is possible to effectively prevent the rotating flange 15 from being damaged such as cracking. Further, when the hub body 13 is hardened by hardening, it is inevitable that deformation occurs due to the heat treatment. If the mounting surface 26 which is the outer surface of the rotation side flange 15 is distorted by this heat treatment deformation, it causes the judder. On the contraryReference exampleIn this case, since the mounting surface 26 is not quenched and hardened (the mounting surface 26 is relatively soft), the hub main body 13 is subjected to a heat treatment including the work of forming the quenched and hardened layer 30. Then, the mounting surface 26 can be easily finished by a lathe or the like. For this reason, a wheel support rolling bearing unit in which the axial runout of the mounting surface 26 accompanying the rotation of the hub body 13 is suppressed to a small extent (good runout accuracy) can be obtained at low cost.
[0026]
  Next, FIGS.1, 2Corresponding to the embodiment of the present inventionFirst exampleIs shown. In the case of this example, the hardened and hardened layer 30a is formed at a position surrounding the entire periphery of the stud 9 which is a screw rod member. For this reason, in the case of this example, the peripheral portion of each conical concave surface 35 indicated by the chain line γ presses the outer surface of the rotation side flange 15 (the inner peripheral portion of the range). Can be backed up.
[0027]
  In the case of this example, the work of forming the quench hardened layer 30a is troublesome, but the effect of preventing the judder from occurring during braking by suppressing the deformation of the rotating flange 15 is as described above. didReference exampleIt becomes better than the case of the first example. The configuration and operation of other parts are as described above.Reference exampleSince it is the same as that in the case of the first example, illustration and description regarding the same part are omitted.
[0028]
  Next, FIGS.1, 3Corresponding to the embodiment of the present inventionSecond exampleIs shown. In the case of this example, a plurality of screw holes 36 (typically 4 to 6 in the case of a passenger car) are formed in a part of the rotation side flange 15 formed on the outer peripheral surface of the hub body 13 in the circumferential direction. It is formed at equal intervals. Then, male screw portions 38 formed at the tip portions of the respective bolts 37, each of which is a screw rod member, are screwed into these screw holes 36 and further tightened.
[0029]
  In the case of this example, a hardened and hardened layer 30b is formed on the entire inner surface of the rotating flange 15 over the entire surface. The reason why the hardened hardening layer 30b is formed over such a wide range is that, in the case of the structure of this example, the screw rod member is the stud 9 as shown in FIGS. This is because a greater bending stress is applied to the rotation-side flange 15 as the bolts 37 are tightened. This point will be described below.
[0030]
  The bending stress for deforming the rotation-side flange 15 includes the force applied in the direction of the arrow β in FIG. 6 to the threaded portion between the male screw portion 38 and the screw hole 36 of each bolt 37, and the inside of the wheel 1. It is generated as a moment based on the force applied in the directions of arrows α and α in FIG. 6 from the peripheral edge of the conical concave surface 35 formed on the side surface via the rotor 2. The magnitude of the bending stress increases in proportion to the distance between the action points of the forces in both directions. In the case of the structure shown in FIGS.₀ Is the radial distance between the flange 27 and the peripheral edge of the conical concave surface 35, whereas in this example, the distance L between the operating points is₁ Is the radial distance between the threaded portion and the inner peripheral edge of the conical concave surface 35. Distance L in FIG.₀ And the distance L in FIG.₁   As is clear from comparison with the above, in this example, the distance L between the operating points is₁ Is large (L₁ > L₀ ), The bending stress that tends to deform the rotation-side flange 15 increases. Therefore, as described above, the hardened and hardened layer 30b is formed over a wide range to prevent the rotation-side flange 15 from being deformed.
[0031]
  In addition, when forming the said hardening hardening layer 30b over a wide range like this example, the hardness of this hardening hardening layer 30b is made too high, As a result, the followability of each said screw hole 36 part deteriorates. Then, the conformability between the screw hole 36 and the male screw portion 38 of each bolt 37 is deteriorated. In addition, an excessive stress may be generated in the male screw portion 38 of each bolt 37 or a part of each screw hole 36, and the durability of the portion may be impaired. Therefore, in the case of this example, the hardness of the quenched and hardened layer 30b is suppressed to about Hv 400 to 500. However, even in that case, the hardness of the proximal end portion of the inner side surface of the rotary side flange 15 that is continuous with the inner diameter side of the quench-hardened layer 30b and is in sliding contact with the distal end edge of the seal lip (see FIG. 8) of the seal ring 22a. Is about Hv 560 to 800. The reason for this is to ensure the bending strength of the rotation side flange 15 and the wear resistance of the part. In order to make the hardness of each part different in this way, after tempering the inner surface of the rotary flange 15 including its base end part, the tempering treatment (tempering treatment) applied to the hardened and hardened layer 30b portion. The temperature of the treatment is set higher than the temperature of the tempering treatment applied to the portion continuous on the inner diameter side.
[0032]
  Next, FIG.Second example of a reference example related to the present inventionIs shown.Reference exampleIn the case ofSecond example of embodimentAs in the case of the above, male screw portions 38 formed at the tip portions of the respective bolts 37, each of which is a screw rod member, are screwed into a plurality of screw holes 36 formed in a part of the rotation side flange 15, and further tightened. Yes. However,Reference exampleIn the case ofReference exampleAs in the case of the first example, the hardened and hardened layer 30 c is formed only on the inner diameter side portion from the center of each bolt 37 with respect to the radial direction of the rotation side flange 15.
[0033]
  Like thisReference exampleIn this case, the effect of preventing the rotation side flange 15 from being deformed as the bolt 37 is tightened is described above.Second example of embodimentAlthough it is slightly inferior to the case of, the work of hardening the hardened layer 30c is facilitated. The configuration and operation of other parts are as described above.Second example of embodimentOr mentioned aboveReference exampleSince it is the same as that of the 1st example, the overlapping illustration and explanation are omitted.
[0034]
  In each of the illustrated examples, the present invention is applied to a structure in which a hub that is an inner ring rotates on an inner diameter side of an outer ring that is supported and fixed to a suspension device in a wheel bearing rolling bearing unit for a drive wheel. It showed about. However, the present invention is not limited to driving wheels, but also applies to wheel bearing rolling bearing units for driven wheels (front wheels of FR and RR vehicles, rear wheels of FF vehicles).it can. Of the wheel bearing rolling bearing units for driven wheels, the outer ring rotation supports the outer ring hub around the inner ring rotation type as well as the inner ring rotation type as well as the inner ring rotation type. The present invention can also be applied to a rolling bearing unit for supporting a wheel of a mold.
[0035]
【The invention's effect】
  Since the rolling bearing unit for supporting a wheel according to the present invention is configured and operates as described above, it is possible to effectively prevent the flange from being deformed when the wheel is fixed to the flange provided on the outer peripheral surface of the hub. it can. Then, the vibration of the braking rotating body supported and fixed to the flange can be prevented, and unpleasant noise and vibration generated during braking can be sufficiently suppressed.
[Brief description of the drawings]
FIG. 1 shows the present invention.Reference examples ofSectional drawing equivalent to the A section of FIG. 8 which shows a 1st example.
FIG. 2 is a view of the rotation side flange and stud taken out and viewed from the right side of FIG.
FIG. 3 shows an embodiment of the present invention.First exampleSectional drawing equivalent to the A section of FIG.
4 is a view seen from the right side of FIG. 3 with only the rotation side flange taken out.
FIG. 5 shows an embodiment of the present invention.Second exampleSectional drawing which shows this in the assembly | attachment state to a suspension apparatus.
6 is an enlarged view of a portion B in FIG.
FIG. 7Second example of reference exampleThe figure similar to FIG.
FIG. 8 is a cross-sectional view showing an example of an assembled state of a wheel support rolling bearing unit that is an object of the present invention.
[Explanation of symbols]
    1 wheel
    2 Rotor
    3 Knuckles
    4 Support holes
    5 Rolling bearing unit for wheel support
    6 Outer ring
    7 volts
    8 Hub
    9 Stud
  10 nuts
  11a, 11b Outer ring raceway
  12 Fixed flange
  13 Hub body
  14 Inner ring
  15 Rotating flange
  16 Mounting hole
  17 First inner ring raceway
  18 Small diameter step
  19 Second inner ring raceway
  20 balls
  21 Cage
  22a, 22b Seal ring
  23 Spline hole
  24 Constant Velocity Joint
  25 Spline shaft
  26 Mounting surface
  27 Buttocks
  28 Serration Department
  29 Male thread
  30, 30a, 30b, 30c Hardened and hardened layer
  31 counterbore
  32 Cylindrical surface
  33 through holes
  34 through holes
  35 Conical concave surface
  36 Screw hole
  37 volts
  38 Male thread

Claims (3)

An inner ring (13, 14) having a double row inner ring raceway (17, 19) on the outer peripheral surface, and a double row outer ring raceway (11a, 11b) on the inner peripheral surface, the periphery of this inner ring (13, 14) A plurality of outer rings (6) arranged concentrically with the inner rings (13, 14) , and a plurality of rollers between the inner ring raceways (17, 19) and the outer ring raceways (11a, 11b). A flange (15) formed on an outer peripheral surface of a rotating side race ring that includes rolling elements (20, 20) that are freely provided and rotates during use among the inner ring (13, 14) and the outer ring (6). In the rolling bearing unit for supporting a wheel used in a state in which the braking rotating body (2) and the wheel (1) are coupled and fixed to the side surface of the wheel by the screw rod members (9, 37) , the flange ( among 15) located around the screw guidance rod (9,37), this Flip guidance rod (9,37) with the clamping portion to be pressed by a portion of the wheel (1) and of the portion overlapping in the axial direction of the screw guidance rod (9,37), the screw guidance rod A rolling bearing unit for supporting a wheel, characterized in that a hardened hardened layer (30a, 30b) is formed at a position surrounding the entire circumference of (9, 37) .   This is a stud that is inserted into the wheel through hole with the middle or distal end protruding from the outer surface of the flange with the screw rod member being press-fitted and fixed in the mounting hole formed at the base end of the flange. Then, by tightening a nut screwed into a portion protruding from the outer surface of the wheel at the tip end portion of the stud, a portion of the inner surface of the wheel has a peripheral portion of the through hole on the outer surface of the flange. The hardened hardened layer is formed on a part of the inner surface of the flange opposite to the part pressed by the peripheral part of the through hole. Rolling bearing unit for wheel support.   The screw rod member is a bolt, and the bolt is inserted into a through hole formed in the wheel, and its tip is screwed into a screw hole formed in the flange and further tightened, so that a part of the inner surface of the wheel is The peripheral part of the through hole is pressed against a part of the outer surface of the flange, and the part of the inner surface of the flange is quenched to the part opposite to the part pressed by the peripheral part of the through hole. The rolling bearing unit for wheel support according to claim 1, wherein a hardened layer is formed.

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