JP2008024064A - Bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing unit capable of improving the stiffness of a hub flange while suppressing increase of the mass of the hub flange, and preventing the occurrence of a stick-slip phenomenon or fretting abrasion. <P>SOLUTION: The bearing unit comprises a static wheel (an outer wheel) 2 fixed to a vehicle body side, rotating wheel (an inner wheel) 4 provided oppositely to the outer wheel and rotating with vehicular wheels while fixed with wheel side structures BR, DW arranged on the vehicular wheel side, rolling elements 6, 7, and the disc-shaped hub flange 12 extending outward from the vehicle body side of the inner wheel and positioned through the wheel side structure and a bolt. On a side surface S of the vehicle body side of the hub flange, a plurality of ribs radially extending from the axis of the inner wheel is provided. A recessed portions having thin wall thickness is provided between each pair of the ribs. The plurality of ribs consists of the ribs having bolt holes in which the bolt is inserted, and the ribs P having no bolt hole. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bearing unit that supports a wheel, and more particularly, to an improvement in the shape of a hub flange that has increased rigidity while suppressing an increase in weight.

2. Description of the Related Art Conventionally, various bearing units for supporting a vehicle wheel (for example, a disc wheel DW) rotatably with respect to a vehicle body (for example, a suspension device (suspension)) are known.
For example, the bearing unit shown in FIG. 6A has a stationary wheel (for example, an outer ring) 2 fixed to the vehicle body side, and is provided opposite to the inner side of the outer ring 2 and connected (fixed) to the wheel side. A rotating wheel (for example, an inner ring) 4 that rotates together with the outer ring 2, and a plurality of rolling elements 6 and 7 that are rotatably incorporated in a double row (for example, two rows) between the outer ring 2 and the inner ring 4.

  The outer ring 2 includes a fixing flange 2a that protrudes outward from the outer peripheral surface and is integrally formed. A fixing bolt 5 is inserted into a fixing hole 2b of the fixing flange 2a, and this is fixed to the housing 8 on the vehicle body side. By fastening to the outer ring 2, the outer ring 2 can be fixed to a suspension device (knuckle) (not shown).

  The inner ring 4 has a substantially cylindrical shape that is engaged with a shaft end 9 of a constant velocity joint (CVJ) on the inner diameter side and rotates together while supporting a wheel-side component (for example, a disc wheel DW or a brake rotor BR of an automobile). A hub 12 having a shape and an inner ring structure 13 fitted to the outer peripheral body of the hub 12 are configured.

  From the wheel side of the hub 12, a disk-shaped hub flange 12 a extending beyond the outer ring 2 toward the outside (radially outward of the hub 12) is projected, and in the vicinity of the extended edge, A plurality of hub bolt holes 12b arranged at predetermined intervals along the circumferential direction are provided, and hub bolts 14 are press-fitted into the plurality of hub bolt holes 12b to fix the wheel side components (disc wheel DW and brake rotor BR). .

  On the other hand, from the prior art, the purpose of reducing the mass and moment of inertia of the hub flange 12a in order to meet the demand for lower fuel consumption of automobiles, and the purpose of reducing the unsprung load to meet the demand for improved riding comfort, As shown in FIG. 3, there is known a hub flange 12a in which a vehicle side surface S of the hub flange 12a is processed to reduce the mass of the hub flange 12a.

  On the vehicle body side inner surface S of such a hub flange 12a, as shown in FIG. 6 (b), the rotation center of the hub flange 12a extends from the periphery of a plurality of hub bolt holes 12b arranged at predetermined intervals along the circumferential direction. The ribs R extending in the radial direction toward the end are arranged in a convex shape, and the side surface S of the vehicle body other than the ribs R of the hub flange 12a is formed with a thin hub flange 12a, so-called meat stealing is performed. ing. In this case, while the strength of the hub flange 12a is maintained by the convex rib R, the mass is reduced by reducing the volume of the hub flange 12a by the meat stealing portion (see the hatched portion in the figure).

Incidentally, the brake rotor BR is combined with a brake device that decelerates the traveling vehicle by braking the rotation of the disc wheel DW. The brake device brakes the rotation of the disc wheel DW by generating a frictional force by sandwiching the brake rotor BR with a brake shoe (not shown) fixed to the vehicle body. In this case, circumferential torque is input to the hub flange 12a when the vehicle is accelerating and decelerating, and circumferential displacement corresponding to the torque is generated.
Further, a variable moment load as a road surface reaction force is input from the disc wheel DW to the hub flange 12a, so that an axial displacement occurs. Further, the hub flange 12a may be warped when the circumferential displacement and the axial displacement are combined.
Further, deformation may occur in the brake rotor BR and the disc wheel DW due to the torque and fluctuating moment load.

  The joint surface between the hub flange 12a and the brake rotor BR or the disc wheel DW is fixed due to the displacement or warpage repeatedly generated in the hub flange 12a and the relative displacement due to the deformation of the brake rotor BR or the disc wheel DW. A so-called stick-slip phenomenon that repeats sliding occurs, and this stick-slip phenomenon may cause wear caused by repeated micro-slip on the joint surface, so-called fretting wear.

Further, in the hub flange 12a, the brake rotor BR, and the disc wheel DW in which the fretting wear has occurred, the fastening force between the hub bolt 14 and the hub nut 14a is reduced, and an abnormal noise that causes discomfort to the driver may occur. There was a problem.
As a countermeasure against such a problem, it is effective to increase the strength of the hub flange 12a. In particular, since the increase in the thickness with respect to the load direction can be expected to have the effect of the cube of the increase amount, the rib has been conventionally used. The thickness of R was increased to give the hub flange 12a the desired strength.
However, in this case, since the mass of the hub flange 12a increases, it becomes difficult to meet the demands for reducing the fuel consumption and improving the riding comfort of the automobile.

JP 07-317755 A

  An object of the present invention is to provide a bearing unit capable of preventing the occurrence of stick-slip phenomenon and fretting wear by suppressing the increase in the mass of the hub flange and increasing the rigidity of the hub flange.

In order to achieve the above object, a bearing unit according to the present invention includes a stationary wheel fixed to the vehicle body side and a wheel-side component provided facing the stationary wheel and disposed on the wheel side together with the wheel. A rotating wheel that rotates, a plurality of rolling elements that are rotatably incorporated between raceway surfaces formed on opposite surfaces of the rotating wheel and the stationary wheel, and an outer side extending from the vehicle body side of the rotating wheel. In the bearing unit including the wheel-side component and the disc-shaped hub flange positioned via the bolt, a plurality of pieces extending radially from the shaft center of the rotating wheel are provided on the side surface of the hub flange on the vehicle body side. A rib is provided, and a thickness stealing portion with a thin wall thickness is provided between the ribs. The plurality of ribs include a rib having a bolt hole into which the bolt is inserted and a rib having no bolt hole. And also bolt Ribs without may be provided between the ribs having bolt holes adjacent to each other in the circumferential direction.
Further, in the bearing unit, a side surface of the hub flange on the vehicle body side has a bolt hole into which the bolt is inserted, and a plurality of ribs extending radially from the shaft center of the rotating wheel are provided. And a plurality of ribs, including a rib having a bolt hole into which the bolt is inserted, and an annular rib continuously extending in the circumferential direction on the outer peripheral side of the hub flange. Alternatively, a plurality of ribs extending radially from the axis of the rotating wheel are provided on the side surface of the hub flange on the vehicle body side, and the thickness of the meat stealer is reduced between the ribs. The plurality of ribs include a rib having a bolt hole into which the bolt is inserted and a rib not having a bolt hole, and is continuously extended in the circumferential direction on the outer peripheral side of the hub flange. Toroidal It may be provided with a drive. In addition, the said annular rib may be continuously extended over the outer diameter side edge part of the some rib which has a bolt hole which inserts a volt | bolt.

  In the above configuration, the stationary wheel is an outer wheel having a fixed flange that can be fixed to the vehicle body on the outer peripheral surface, and a plurality of outer ring side raceway surfaces arranged side by side on the inner peripheral surface. A hub flange that can be fixed is provided on the outer peripheral surface, and is configured by a substantially cylindrical hub in which the shaft end of the constant velocity joint is engaged on the inner diameter side, and an inner ring structure fitted on the outer peripheral surface of the hub on the vehicle body side, The outer peripheral surface of the hub and the inner ring structure may be provided in a bearing unit composed of an inner ring having inner ring side raceways arranged side by side, and the stationary wheel is a fixed flange that can be fixed to the vehicle body side. Is provided on the outer peripheral surface, and a plurality of outer ring side raceway surfaces are arranged side by side on the inner peripheral surface. The rotating wheel has a hub flange that can be fixed to the wheel side on the outer peripheral surface, and a constant velocity joint on the inner diameter side. A substantially cylindrical hub with which the shaft end is engaged and a plurality of hubs fitted on the outer peripheral surface of the hub. Is composed of a number of inner ring structure, may be provided in the bearing unit consists of an inner ring formed by juxtaposed inner ring raceway surface, respectively on the outer peripheral surface of the inner ring structure. Furthermore, the rotating wheel is an outer ring provided with a hub flange that can be fixed to the wheel side on the outer peripheral surface, and a plurality of outer ring side raceways are arranged side by side on the inner peripheral surface. The bearing unit may be provided with a plurality of inner rings arranged side by side with a raceway surface.

  ADVANTAGE OF THE INVENTION According to this invention, the rigidity of a hub flange can be made high, suppressing the increase in the mass of a hub flange, and the bearing unit which can prevent generation | occurrence | production of a stick slip phenomenon and fretting wear can be provided.

Hereinafter, a bearing unit according to an embodiment of the present invention will be described with reference to the accompanying drawings. Note that, in the bearing unit of the present embodiment, the same configuration as the conventional one is adopted as the overall configuration of the bearing unit.
For example, in the bearing unit of the present embodiment, as shown in FIG. 1A, the outer ring 2 as a stationary ring that is fixed to the vehicle body side and is always kept in a non-rotating state is opposed to the inner side of the outer ring 2. The inner ring 4 as a rotating wheel that is provided and connected (fixed) to the wheel side and rotates together with the wheel, and a plurality of rollers that are rotatably incorporated in a double row (for example, two rows) between the outer ring 2 and the inner ring 4. The moving bodies 6 and 7 are provided.

  In this case, the outer ring 2 has a hollow cylindrical shape and is disposed so as to cover the outer periphery of the inner ring 4. Between the outer ring 2 and the inner ring 4, a seal member (for sealing the inside of the bearing unit) A pack seal 10a on the vehicle body side and a lip seal 10b on the wheel side are provided. In addition, although the ball | bowl is illustrated in drawing as the rolling elements 6 and 7, a roller may be applied according to the structure and kind of bearing unit.

  The outer ring 2 is integrally formed with a fixing flange 2a protruding outward from the outer peripheral surface thereof, and a fixing bolt 5 is inserted into a fixing hole 2b of the fixing flange 2a, and this is inserted into a housing 8 on the vehicle body side. By fastening, the outer ring 2 can be fixed to a suspension device (knuckle) (not shown).

  The inner ring 4 has a substantially cylindrical shape that is engaged with a shaft end 9 of a constant velocity joint (CVJ) on the inner diameter side and rotates together while supporting a wheel-side component (for example, a disc wheel DW or a brake rotor BR of an automobile). A hub 12 having a shape and an inner ring structure 13 fitted to the outer peripheral body of the hub 12 are configured. In this case, by fastening the shaft end 9 of the constant velocity joint and the vehicle body side end surface 12c of the hub 12 with the lock nut 9a, the vehicle body side end portion 9b of the constant velocity joint and the inner ring component 13 come into contact with each other. A predetermined preload is applied to the bearing unit. In this state, the rolling elements 6 and 7 form a predetermined contact angle with each other of the outer ring 2 and the inner ring 4 (the hub 12 and the inner ring constituting body 13). It is rotatably assembled in contact with the raceway surface.

  Further, the constant velocity joint in which the end portion 9 is engaged with the hub 12 of the bearing unit is such that, for example, the constant velocity joint freely changes in angle in response to a change in the angle of the propeller shaft (or drive shaft). Thus, a driving force having a predetermined torque is smoothly transmitted to the disc wheel DW through the bearing unit.

  Further, a disc-shaped hub flange 12a to which a wheel-side component (disc wheel DW or brake rotor BR) is fixed is projected from the outer peripheral surface wheel side of the hub 12. The hub flange 12a extends in a disk shape from the position spaced a predetermined distance in the wheel direction from the raceway surface 12e with which the rolling element 7 on the wheel side of the hub 12 contacts to the outside (radially outward of the hub 12). In the vicinity of the extended edge, a plurality of hub bolt holes 12b arranged at predetermined intervals along the circumferential direction are provided, and hub bolts 14 are press-fitted into the plurality of hub bolt holes 12b.

  In this case, the brake rotor BR is inserted by positioning by inserting a plurality of hub bolts 14 into a plurality of bolt holes formed in the brake rotor BR, and the disc wheel DW also forms a plurality of hub bolts 14 on the disc wheel DW. The disc wheel DW and the brake rotor BR are fastened together with the hub flange 12a by being inserted into the plurality of bolt holes and tightened with the hub nut 14a, and the disc wheel DW and the brake rotor BR are aligned with the opposing surfaces without gaps. It can be positioned and fixed with respect to the hub flange 12a.

Further, as a characteristic configuration of the present invention, the vehicle body side inner surface S of the hub flange 12a of the present embodiment has a rotation center (axial center) of the hub flange 12a as a center as shown in FIG. A plurality of ribs R extending radially to the outer peripheral edge of the hub flange 12a are provided in a convex shape, and a hub bolt hole 12b is provided in the area of each rib R. That is, the same number of ribs R as the hub bolt holes 12b are arranged.
An annular rib D is arranged on the inner peripheral side of the hub flange 12a, and the inner peripheral side of the hub flange 12a of the rib R has a gentle curved shape and is integrated with the outer peripheral edge of the rib D. ing.
Further, between the ribs R adjacent in the circumferential direction, ribs P extending radially from the rotation center (axial center) of the hub flange 12a to the outer peripheral edge of the hub flange 12a are arranged in a convex shape. The inner peripheral side of the hub flange 12a is integrated with the outer peripheral edge of the rib D.
In the present embodiment, as an example, the ribs P are each provided with one rib P between the ribs R adjacent in the circumferential direction. However, the number of ribs P is not limited to this. For example, two ribs P are provided. Ribs P may be arranged.

Further, in the region other than the rib R and the rib P on the side surface S of the vehicle body side of the hub flange 12a, the hub flange 12a is formed with a small thickness, and a so-called meat stealing portion (shaded portion in the figure) U is disposed. By providing the meat stealing portion U on the vehicle body side surface S of the hub flange 12a in this manner, the rib R and the rib P are formed in a convex shape with a thickness before the meat stealing.
Moreover, since the rib R and the rib P have the thickness before carrying out the meat stealing to the hub flange 12a, the rigidity of the hub flange 12a becomes high by the thickness of the rib R and the rib P. Further, since the meat stealing portion U is divided by the rib P and its region is small, the region where the thickness of the hub flange 12a that causes a reduction in rigidity is small is also small, and the circumferential direction of the hub flange 12a is reduced. , And the warpage of the hub flange 12a can be suppressed, so that the rigidity of the hub flange 12a is maintained high.
Further, since the rigidity of the hub flange 12a is increased, the stick-slip phenomenon is less likely to occur, and further, fretting wear is less likely to occur, so that the fastening force between the hub bolt 14 and the hub nut 14a is not reduced. It is also possible to suppress the generation of unusual noise that causes discomfort to the person.

  In order to suppress an increase in the mass of the hub flange 12a, it is desirable that the circumferential width of the rib P be formed by dividing the circumferential width of the rib R. According to this, the circumferential width of the rib R disposed on the hub flange 12a is formed smaller than that of the conventional rib R, and the total width of the rib P and rib R is not different from the conventional one. The mass of 12a does not increase.

  In the present embodiment, as an example, five hub bolt holes 12b are arranged in the circumferential direction of the hub flange 12, so that five ribs R are arranged while including the bolt holes 12b in the region, Five ribs P are arranged between the five ribs R. The ribs R are arranged to increase or decrease according to the number of hub bolt holes 12b, and according to the number between the ribs R. The number of ribs P is also increased or decreased. For example, when four hub bolt holes 12b are arranged in the circumferential direction of the hub flange 12, the number of ribs R and ribs P is four.

"Modification 1"
Furthermore, in this embodiment, the vehicle body side surface S of the hub flange 12a extends in the radial direction of the hub flange 12a, and includes a plurality of ribs R including the bolt holes in the region, and between the circumferential directions of the ribs R. 2 and extending in the radial direction of the hub flange 12a, and a rib P not including the bolt hole is disposed in the region. As a modification, as shown in FIG. Instead of the rib P, the side surface S may be provided with an annular rib T that is continuously extended in the circumferential direction on the outer peripheral side of the hub flange 12a.

In this case, a plurality of radial ribs R extending from the rotation center of the hub flange 12a to the outer peripheral edge of the hub flange 12a are arranged in a convex shape, and the hub bolt hole 12b is included in the area of one rib R. The ribs R are arranged in the same number as the hub bolt holes 12b. An annular rib D is arranged on the inner peripheral side of the hub flange 12a, and the inner peripheral side of the hub flange 12a of the rib R has a gentle curved shape and is integrated with the outer peripheral edge of the rib D. ing.
Further, on the outer peripheral side of the hub flange 12a, an annular rib T extending continuously in the circumferential direction over the outer diameter side end portion of the rib R is arranged in a convex shape, and the rib R is formed of the rib T. Integrated with the inner periphery.
Further, the vehicle body side surface S other than the rib R and the rib T of the hub flange 12a is provided with a meat stealing portion (shaded portion in the figure) U in which the hub flange 12a is formed thin.
In this case, since the ribs T are continuously arranged in the circumferential direction at the outer peripheral portion of the hub flange 12a, the circumferential displacement of the hub flange 12a can be reduced, and the warpage of the hub flange 12a can be suppressed. Therefore, the rigidity of the hub flange 12a is increased.
In the first modification, the rib R is integrated with the inner peripheral edge of the rib T. However, as long as the rigidity of the hub flange is ensured, the rib R and the rib T are not integrated but separated. May be.

  Further, since the meat stealing portion (shaded portion in the figure) U is surrounded by the rib R, the rib T, and the rib D on the inner peripheral side of the hub flange 12a, the hub flange 12a is surrounded so as to surround the meat stealing portion U. The thick portion is arranged, and the axial rigidity of the hub flange 12a is maintained at the thick portion, so that the meat stealing portion U can be made thin. Thereby, since the increase in the mass of the rib T formed in a convex shape can be offset by reducing the thickness of the meat stealing portion U, an increase in the mass of the hub flange 12a can be suppressed.

"Modification 2"
Furthermore, as a second modification, as shown in FIG. 3, a plurality of ribs R extending in the radial direction of the hub flange 12a and including the bolt holes in the region are provided on the vehicle body side surface S of the hub flange 12a. The rib P disposed between the ribs R in the circumferential direction and extending in the radial direction of the hub flange 12a does not include the bolt hole in the region, and the vehicle body side surface S of the hub flange 12a includes the hub flange 12a. The rib T extended continuously in the circumferential direction may be combined with the outer peripheral side.
Thereby, the displacement of the axial direction of the hub flange 12a and the circumferential direction can be reduced.

Moreover, in this embodiment and each modification mentioned above, areas other than the ribs (R, P, T) on the vehicle body side surface S of the hub flange 12a are meat stealing portions (each figure) that form the hub flange 12a thin. The hatched portion U is arranged in a hole that penetrates the vehicle body side surface S and the wheel side surface of the hub flange 12a as long as the rigidity of the hub flange 12a is maintained. It may be formed.
"Modification 3"

The overall configuration of the bearing unit to which the hub flange 12a described in the present embodiment and each modification described above is applied is not limited to the configuration of the bearing unit described in the present embodiment, and includes the hub flange 12a. If so, the present invention can be applied to other bearing units.
For example, the present invention can be applied to a bearing unit as shown in FIG. The inner ring 4 (rotating wheel) has a hub flange 12a that extends outward (toward the radial direction of the outer ring 2) toward the wheel side of the outer ring 2 and can be fixed to the wheel side on the outer peripheral surface. ing.
Further, a substantially cylindrical hub 12 to which the shaft end 9 of the constant velocity joint is engaged is provided on the inner diameter side of the inner ring 4, and a plurality of inner ring constituting bodies 16 (in addition to the hub 12, the inner ring is provided on the outer peripheral surface of the hub 12. 4, members 13, 15) are fitted together, and inner ring side raceways are arranged in parallel on the outer circumferential surface of the inner ring constituting body 16.
The present invention can be applied not only to driving wheels but also to driven wheels.
Further, the inner ring component 16 is plastically deformed at the end portion of the hub 12 on the vehicle body side and the inner ring component 16 is crimped (contacted) along the peripheral end of the inner ring component 16. It can be fixed to the inner ring 4 (hub 12).
“Modification 4”

Further, the present invention is also applied to a bearing unit as shown in FIG. 5, and the outer ring 2 (rotating wheel) extends outward (toward the radial direction of the outer ring 2) toward the wheel side of the outer ring 2. A fixable hub flange 12a is provided on the outer peripheral surface, and a plurality of outer ring side raceway surfaces are arranged in parallel on the inner peripheral surface.
The inner ring 4 (stationary ring) is composed of a plurality of inner ring constituent bodies (16, 17), and the inner ring side raceway surface is provided on the outer circumferential surface thereof, and they are arranged in parallel.

It is explanatory drawing of the bearing unit by this invention, (a) is a schematic sectional drawing of a bearing unit, (b) is explanatory drawing of the vehicle body side side surface of a hub flange. It is explanatory drawing which shows the modification of a hub flange. It is explanatory drawing which shows the other modification of a hub flange. It is a schematic sectional drawing of the other bearing unit to which this invention is applied. It is a schematic sectional drawing of the other bearing unit to which this invention is applied. It is explanatory drawing of the conventional bearing unit, (a) is a schematic sectional drawing of a bearing unit, (b) is explanatory drawing of the vehicle body side side surface of a hub flange.

Explanation of symbols

2 outer ring 2a fixing flange 2b fixing flange fixing hole 4 inner ring 5 fixing bolt 6, 7 rolling element 8 housing 9 constant velocity joint shaft end 9a lock nut 12 hub 12a hub flange 12b hub bolt hole 14 hub bolt 14a hub nut DW disc wheel BR Brake rotor S Hub side flange side R, P, T, D rib

Claims (8)

A stationary wheel fixed to the vehicle body side,
A rotating wheel that is provided facing the stationary wheel and that is disposed on the wheel side and that rotates together with the wheel.
A plurality of rolling elements incorporated in a freely rolling manner between the raceway surfaces formed on the opposing surfaces of the rotating wheel and the stationary wheel,
In a bearing unit including a disk-shaped hub flange that extends outward from the vehicle body side of the rotating wheel and is positioned via a wheel-side component and a bolt,
A plurality of ribs extending radially from the axis of the rotating wheel are provided on the side surface of the hub flange on the vehicle body, and a meat stealing portion with a thin wall thickness is provided between each rib.
A plurality of ribs include ribs having bolt holes into which the bolts are inserted,
A bearing unit comprising a rib having no bolt hole.   The bearing unit according to claim 1, wherein a rib having no bolt hole is provided between ribs having bolt holes adjacent in the circumferential direction. A stationary wheel that is fixed to the vehicle body and maintained in a non-rotating state at all times;
A rotating wheel that is provided facing the stationary wheel and that is disposed on the wheel side and that rotates together with the wheel.
A plurality of rolling elements incorporated in a freely rolling manner between the raceway surfaces formed on the opposing surfaces of the rotating wheel and the stationary wheel,
In a bearing unit including a disk-shaped hub flange that extends outward from the vehicle body side of the rotating wheel and is positioned via a wheel-side component and a bolt,
The hub flange has a bolt hole into which the bolt is inserted, and a plurality of ribs extending radially from the axis of the rotating wheel, and a stealing with a thin wall between the ribs. Part is provided,
A bearing unit comprising an annular rib continuously extending in the circumferential direction on an outer peripheral side of the hub flange. A stationary wheel that is fixed to the vehicle body and maintained in a non-rotating state at all times;
A rotating wheel that is provided facing the stationary wheel and that is disposed on the wheel side and that rotates together with the wheel.
A plurality of rolling elements incorporated in a freely rolling manner between the raceway surfaces formed on the opposing surfaces of the rotating wheel and the stationary wheel,
In a bearing unit including a disk-shaped hub flange that extends outward from the vehicle body side of the rotating wheel and is positioned via a wheel-side component and a bolt,
A plurality of ribs extending radially from the axis of the rotating wheel are provided on the side surface of the hub flange on the vehicle body, and a meat stealing portion with a thin wall thickness is provided between each rib.
The plurality of ribs are composed of ribs having bolt holes into which the bolts are inserted and ribs not having bolt holes,
A bearing unit comprising an annular rib continuously extending in the circumferential direction on an outer peripheral side of the hub flange.   5. The bearing unit according to claim 3, wherein the annular rib is continuously extended over the outer diameter side end portions of the plurality of ribs. A stationary wheel is an outer ring that is provided with a fixing flange that can be fixed to the vehicle body side on the outer peripheral surface, and a plurality of outer ring side raceway surfaces arranged in parallel on the inner peripheral surface.
The rotating wheel has a hub flange that can be fixed to the wheel side on the outer peripheral surface, a substantially cylindrical hub that engages the shaft end of the constant velocity joint on the inner diameter side, and an inner ring that is fitted on the outer peripheral surface of the hub on the vehicle body side. 6. The structure according to claim 1, further comprising an inner ring formed by juxtaposing inner raceway raceways on outer peripheral surfaces of the hub and the inner ring structure. The bearing unit described. A stationary wheel is an outer ring that is provided with a fixing flange that can be fixed to the vehicle body side on the outer peripheral surface, and a plurality of outer ring side raceway surfaces arranged in parallel on the inner peripheral surface.
The rotating wheel has a hub flange that can be fixed to the wheel side on the outer peripheral surface, a substantially cylindrical hub that is engaged with the shaft end of the constant velocity joint on the inner diameter side, and a plurality of fittings fitted on the outer peripheral surface of the hub. 6. The inner ring structure according to any one of claims 1 to 5, wherein the inner ring structure includes inner rings formed by arranging inner ring side raceways on the outer circumferential surface of the inner ring structure. Bearing unit. The rotating wheel is an outer ring provided with a hub flange that can be fixed to the wheel side on the outer peripheral surface, and a plurality of outer ring side raceway surfaces arranged side by side on the inner peripheral surface.
The bearing unit according to any one of claims 1 to 5, wherein the stationary ring includes a plurality of inner rings arranged in parallel by providing inner ring side raceway surfaces on the outer peripheral surface.

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