JP2022153809A - hub unit bearing - Google Patents

Abstract

To provide a hub unit bearing capable of preventing moisture adhering to an axially inside surface of a rotary flange from reaching a portion between an outside seal ring and a hub, and capable of securing durability of the rotary flange even when an axial thickness of the rotary flange is made small.SOLUTION: A rotary flange 10 has a radially outward facing stepped part 18 connecting an axially inside surface of a root part 14, which is a radially inside part, and an axially inside surface of a thickness change part 15, which is a radially outside part. The thickness change part 15 has a plurality of thick parts 21 extending radially from the root part 14, and a plurality of thin parts 22 connecting the thick parts 21 adjacent to each other in a circumferential direction. The rotary flange 10 has a flange through hole 23 axially penetrating through each of radially inside end parts of portions sandwiched between the thick parts 21 adjacent to each other in the circumferential direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a hub unit bearing for rotatably supporting a vehicle wheel with respect to a suspension system.

A vehicle wheel is rotatably supported with respect to a suspension system by a hub unit bearing. A hub unit bearing comprises an outer ring having a double-row outer ring raceway on its inner peripheral surface, a hub having a double-row inner ring raceway on its outer peripheral surface, and between the double-row outer ring raceway and the double-row inner ring raceway, A plurality of rolling elements are arranged for each row. The outer race is supported and fixed to the suspension system and does not rotate during use. The hub rotates together with the wheel when in use. For this purpose, the hub has a rotary flange for coupling and fixing the wheel, projecting radially outward from an axially outer portion located axially outside the outer ring. An axially outer opening of the rolling element installation space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub is closed by an outer seal ring attached to the axially outer end of the outer ring. . Regarding the hub unit bearing, the axially outer side is the widthwise outer side of the vehicle when assembled to the vehicle, and the axially inner side is the widthwise central side of the vehicle when the hub unit bearing is assembled to the vehicle.

Regarding such a hub unit bearing, Japanese Patent Application Laid-Open No. 2015-148253 (Patent Document 1) discloses that a truncated cone-shaped shoulder provided on the radially inner portion of the axially inner surface of the rotary flange has a A structure with an annular drain is disclosed. According to this structure, when the vehicle stops after running in the rain, water such as muddy water that moves downward along the axial inner surface of the rotary flange is drained from the upper portion of the axial inner surface. By guiding the moisture downward through the groove, it is possible to suppress the moisture from reaching the seal sliding contact portion of the outer seal ring.

JP 2015-148253 A

Hub unit bearings are subjected to a large moment load based on road surface reaction force when the vehicle turns, so they must have a long life in terms of rolling fatigue and high rigidity to prevent wheel alignment changes. is required. In order to meet such demands, it is necessary to increase the distance between rows of rolling elements.

However, in the conventional hub unit bearing described above, if the distance between rows of rolling elements is increased while the overall axial dimension is kept constant, the axial thickness of the rotary flange must be reduced. As a result, the radius of curvature of the cross-sectional shape of the drainage groove becomes smaller, so stress tends to concentrate on the annular groove.

On the other hand, if the distance between rows of rolling elements is increased while maintaining the axial thickness of the rotating flange in order to avoid stress concentration in the annular groove, the axial dimension of the entire hub unit bearing will increase, resulting in a larger hub. The weight of the unit bearing increases. Since the weight of the hub unit bearing is included in the unsprung weight of the vehicle, an increase in the weight of the hub unit bearing is undesirable from the viewpoint of improving the steering stability and ride comfort of the vehicle.

The present invention is capable of suppressing moisture adhering to the axial inner surface of a rotary flange from reaching a portion between an outer seal ring and a hub, and even when the axial thickness of the rotary flange is reduced, the rotary flange can be prevented from rotating. An object of the present invention is to provide a hub unit bearing that facilitates ensuring the durability of a flange.

A hub unit bearing according to one aspect of the present invention includes an outer ring, a hub, a plurality of rolling elements, and an outer seal ring.
The outer ring has a double-row outer ring raceway on its inner peripheral surface.
The hub has a double-row inner ring raceway on its outer peripheral surface, and a rotary flange that protrudes radially outward at a portion located axially outside the outer ring. It has mounting holes for inserting hub bolts at a plurality of locations in the circumferential direction.
A plurality of the rolling elements are arranged for each row between the double-row outer ring raceway and the double-row inner ring raceway.
The outer seal ring is attached to an axially outer end of the outer ring and closes an axially outer opening of a rolling element installation space existing between an inner peripheral surface of the outer ring and an outer peripheral surface of the hub. .
The rotating flange has a radially inner portion, a root portion whose axial thickness does not change in the circumferential direction, and a radially outer portion, which has a wall thickness changing portion whose axial thickness changes in the circumferential direction. The axially inner side surface of the root portion and the axially inner side surface of the thickness change portion are connected by a radially outwardly directed stepped portion provided in the root portion.
The thickness change portion includes a plurality of thick portions each extending in a radial direction from the root portion and having the mounting holes, and a plurality of thick portions connecting the thick portions adjacent to each other in the circumferential direction. and the axial inner surface of the thin portion is arranged axially outside the axial inner surface of the thick portion.
The rotating flange has a flange through-hole axially penetrating through each of radially inner ends of a portion sandwiched between the thick-walled portions adjacent in the circumferential direction. A radially inner end of the axially inner opening is in contact with the stepped portion or positioned radially inwardly of the stepped portion as viewed from the axially inner side.

In one aspect of the present invention, of the inner peripheral surface of the flange through-hole, the radially inner portion of the rotary flange is inclined radially inward of the rotary flange as it extends axially outward. ing. In this case, the flange through-hole may be, for example, a tapered hole whose inner diameter increases axially outward, or a circular hole inclined radially inward of the rotary flange as axially outward. It can be configured by However, the present invention also includes a case where the flange through-hole is formed of a circular hole extending in the same direction (parallel to) the central axis of the hub unit bearing.

According to the hub unit bearing of one aspect of the present invention, water adhering to the axial inner surface of the rotary flange can be suppressed from reaching the portion between the outer seal ring and the hub, and the axial direction of the rotary flange can be prevented. Even if the thickness is reduced, it is easy to ensure the durability of the rotary flange.

FIG. 1 is a cross-sectional view of a hub unit bearing according to a first embodiment of the invention. FIG. 2 is an enlarged view of the upper left part of FIG. FIG. 3 is a view of the hub that constitutes the hub unit bearing of the first example, viewed from the inside in the axial direction. 4(A) and 4(B) are views of the upper half of the hub to which hub bolts are attached in relation to the hub unit bearing of the first example, viewed from the inside in the axial direction. (A) shows a rotational position in which the flange through-hole is positioned at the highest position in the vertical direction, and FIG. 4B shows a rotational position at which the hub bolt is positioned at the highest position in the vertical direction. FIG. 5 is a diagram corresponding to FIG. 2 regarding the second example of the embodiment of the present invention. FIG. 6 is a diagram corresponding to FIG. 2 regarding the third example of the embodiment of the invention. FIG. 7 is a diagram corresponding to FIG. 2 regarding a fourth example of the embodiment of the invention. FIG. 8 is a diagram corresponding to FIG. 2 regarding a fifth example of the embodiment of the present invention.

[First example of embodiment]
A first example of an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

A hub unit bearing 1 of this example is for a drive wheel and includes an outer ring 2, a hub 3, a plurality of rolling elements 4a and 4b, and an outer seal ring 5. As shown in FIG. However, the present invention can also be applied to hub unit bearings for driven wheels. Regarding the hub unit bearing 1, the axially outer side is the left side in FIGS. It is the right side of FIGS. 1 and 2, which is the center side in the width direction.

The outer ring 2 has double-row outer ring raceways 6a and 6b on its inner peripheral surface, and a stationary flange 7 projecting radially outward from its axial intermediate portion. The stationary flange 7 has support holes 8 extending axially through it at a plurality of locations in the circumferential direction of the radially intermediate portion. The outer ring 2 is supported and fixed to the suspension system by means of support bolts screwed into support holes 8 of the stationary flange 7, so that it does not rotate even when the wheel rotates.

The hub 3 has double-row inner ring raceways 9a and 9b facing the double-row outer ring raceways 6a and 6b on its outer peripheral surface, and a portion located axially outside of the outer ring 2 protruding radially outward. It has a rotating flange 10 that rotates. Further, the hub 3 has mounting holes 11 for inserting hub bolts 13 at a plurality of positions in the circumferential direction of the rotary flange 10 . The hub 3 has a cylindrical pilot portion 12 at its axially outer end. In this example, a hub bolt 13 is inserted into each of the mounting holes 11, specifically, press-fitted by serration fitting.

The rotary flange 10 is configured in the shape of a circular disk as a whole, and has a root portion 14 on the radially inner side whose axial thickness does not change with respect to the circumferential direction, and a radially outer portion with an axial thickness of has a thickness change portion 15 that changes in the circumferential direction. The axial inner surface of the root portion 14 and the axial inner surface of the thickness change portion 15 are connected by a stepped portion 18 provided in the root portion 14 and facing radially outward.

In this example, the root portion 14 has an inclined surface portion 17 at the radially outer end portion of the axial inner surface. The inclined surface portion 17 is inclined radially outward as it extends axially outward. In this example, the inclined surface portion 17 has a concave arcuate cross-sectional shape. However, when carrying out the present invention, the cross-sectional shape of the inclined surface portion can also be a linear shape. In this example, the root portion 14 has a flat portion 16 at a radially intermediate portion of the axial inner surface, that is, a portion adjacent to the radially inner side of the inclined surface portion 17 . The flat portion 16 is formed of a ring-shaped flat surface perpendicular to the central axis of the hub 3 . In the case of carrying out the present invention, the flat portion 16 may be formed entirely on the radial intermediate portion and the radially outer end portion of the axial inner surface of the root portion 14 . The root portion 14 has a curved surface portion 19 at the radially inner end portion of the axial inner surface, that is, at a portion adjacent to the radially inner side of the flat portion 16 . The curved surface portion 19 connects the flat portion 16 and a cylindrical surface portion 20 provided on the outer peripheral surface of the axially intermediate portion of the hub 3, and has a concave arcuate cross-sectional shape. The stepped portion 18 of the root portion 14 is formed of a radially outwardly directed cylindrical surface extending axially outwardly from the radially outer end portion of the inclined surface portion 17 . However, when carrying out the present invention, the stepped portion can also be configured by a tapered surface that is inclined in a direction in which the outer diameter decreases toward the axially outer side. If the stepped portion is configured with such a tapered surface, it is possible to easily discharge the water adhering to the stepped portion to the outside in the axial direction, as will be described later. Further, when carrying out the present invention, the stepped portion may be configured by a tapered surface that is slightly inclined in a direction in which the outer diameter decreases toward the inner side in the axial direction.

The thickness change portion 15 is formed by connecting a plurality of thick portions 21 each extending in the radial direction from the root portion 14 and having the mounting hole 11 and the thick portions 21 adjacent to each other in the circumferential direction. and a plurality of thin portions 22 . The axial inner surface of the thin portion 22 is arranged axially outside the axial inner surface of the thick portion 21 . In this example, the axial outer surface of the rotary flange 10 including the thickness change portion 15 is formed by a circular ring-shaped plane perpendicular to the central axis of the hub 3 .

The number of thick portions 21 and thin portions 22 is arbitrary, but in this example, the thickness changing portion 15 has five thick portions 21 and five thin portions 22 . These thick-walled portions 21 and thin-walled portions 22 are alternately arranged at equal pitches in the circumferential direction. The axial inner surface of the thick portion 21 is formed by a plane perpendicular to the central axis of the hub 3 . The axially inner side surface of the thin portion 22 is formed of an inclined surface that is inclined in the axially outward direction toward the radially outward side. In this example, as shown in FIG. 2, the axially inner surface of the thin portion 22 has a concave arcuate cross-sectional shape at the radially inner end, and the other portion, that is, the radially intermediate portion. and the radially outer end have a linear cross-sectional shape.

In this example, as shown in FIG. 3, each of the thick portions 21 has a substantially trapezoidal shape in which the width in the circumferential direction gradually decreases toward the radially outer side when viewed from the axially inner side. On the other hand, as shown in FIG. 3, each of the thin-walled portions 22 has a substantially fan-like shape in which the width in the circumferential direction gradually increases toward the outer side in the radial direction when viewed from the inner side in the axial direction.

The rotary flange 10 is provided at each of the radially inner ends of the portions sandwiched between the thick portions 21 adjacent in the circumferential direction, that is, at each of the radially inner ends of the thin portions 22 . It has a flange through-hole 23 penetrating in the direction. As shown in FIG. 3 , the radially inner end (P portion) of the axially inner opening of the flange through-hole 23 is in contact with the stepped portion 18 when viewed from the axially inner side. In this example, the axial inner opening of the flange through-hole 23 has both ends in the circumferential direction when viewed from the inner side in the axial direction. abutting the ends. In this example, such a flange through-hole 23 is configured as a circular hole extending in the axial direction of the hub 3 . However, when carrying out the present invention, any shape can be adopted for the flange through hole as long as it is a shape that allows water to be discharged to the outside in the axial direction of the rotary flange. Further, when carrying out the present invention, the axially inner opening of the flange through-hole is not in contact with the circumferential end of the axially inner side surface of the thick portion when viewed from the axially inner side. Then, it is possible to employ a configuration in which the step surface 41 that connects the axial inner surface of the thick portion 21 and the axial inner surface of the thin portion 22 is not in contact.

In this example, the hub 3 is formed by combining a hub ring 24 and an inner ring 25 . The axially outer inner ring raceway 9 a is provided on the outer peripheral surface of the hub wheel 24 at the axially intermediate portion. The rotating flange 10 and the pilot portion 12 are provided on the axially outer portion of the hub wheel 24 . The inner ring raceway 9 b on the inner side in the axial direction is provided on the outer peripheral surface of the inner ring 25 . The inner ring 25 is externally fitted and fixed to the axially inner portion of the hub ring 24 . Since the hub unit bearing 1 of this example is for a drive wheel, the hub wheel 24 has a spline hole 26 in the radial center portion for spline engagement with a spline shaft portion constituting a drive shaft member.

In addition, the present invention provides a hub unit bearing having a crimped portion that presses down the axially inner surface of the inner ring at the axially inner end portion of the hub ring, and an inner ring raceway on the axially outer side that is fitted onto the hub ring. It can also be applied to a hub unit bearing provided on the outer peripheral surface of another inner ring.

A plurality of rolling elements 4a and 4b are arranged for each row between the double-row outer ring raceways 6a and 6b and the double-row inner ring raceways 9a and 9b, and the cages 30a and 30a for the respective rows are arranged. 30b to be rotatably held. Thereby, the hub 3 is rotatably supported radially inwardly of the outer ring 2 .

In this example, balls are used as the rolling elements 4a and 4b, but tapered rollers can also be used as the rolling elements. In this example, the pitch diameter of the rolling elements 4a in the axially outer row is the same as the pitch diameter of the rolling elements 4b in the axially inner row. However, the present invention can also be applied to a different diameter PCD type hub unit bearing in which the pitch diameter of the rolling elements in the axially inner row and the pitch diameter of the rolling elements in the axially outer row are different from each other.

The outer seal ring 5 is attached to the axially outer end of the outer ring 2 , and closes the axially outer opening of the rolling element installation space 31 existing between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 . blocking. As a result, grease for lubrication existing in the rolling element installation space 31 leaks into the external space through the opening portion on the axial outer side of the rolling element installation space 31, or foreign matter such as muddy water enters the rolling element installation space 31 from the external space. to prevent intrusion.

The outer seal ring 5 is formed by combining a metal core 32 and a seal material 33 .

The cored bar 32 is formed by pressing a metal plate, and has an annular shape as a whole. The core metal 32 includes a cylindrical fitting tube portion 34, a circular plate-shaped standing plate portion 35 bent radially outward from an axially outer end portion of the fitting tube portion 34, and a fitting tube portion. a support plate portion 36 having a crank-shaped cross-sectional shape that is bent radially inward and axially outward from the axially inner end of the portion 34 in a U-shape, and the front half portion is bent radially inward; Prepare. The core bar 32 is supported and fixed to the outer ring 2 by fitting the fitting tube portion 34 to the inner peripheral surface of the outer end portion of the outer ring 2 in the axial direction by interference fit. Further, in this state, the axial position of the core metal 32 with respect to the outer ring 2 is regulated by bringing the axial inner side surface of the upright plate portion 35 into contact with the axially outer end surface of the outer ring 2 .

The seal member 33 is made of an elastic material such as an elastomer containing rubber and is formed in an annular shape as a whole, and is coupled and fixed to the metal core 32 . The seal member 33 has three seal lips 37a, 37b, and 37c on its radially inner side, and has a dam portion 38 and an eaves lip 39 on its radially outer side.

Of the three seal lips 37a, 37b, and 37c, the tip of the seal lip 37a closest to the rolling element installation space 31 is in sliding contact with the cylindrical surface portion 20 of the hub 3 over the entire circumference. The end portion of the seal lip 37b, which is the second closest to the rolling element installation space 31, is in sliding contact with the curved surface portion 19 of the rotary flange 10 over the entire circumference. The end of the seal lip 37c furthest from the rolling element installation space 31 is in sliding contact with the flat portion 16 of the rotary flange 10 over the entire circumference.

The dam portion 38 covers the radially outer end portion of the upright plate portion 35 of the core bar 32 and has an outer diameter dimension larger than that of the axially outer end portion of the outer ring 2 . The dam portion 38 dams water such as muddy water flowing axially outward along the outer peripheral surface of the outer ring 2 , thereby preventing the water from reaching the portion between the outer seal ring 5 and the hub 3 . prevent.

The eaves lip 39 is configured in a conical tubular shape, and the axially inner end portion, which is the base end portion, is connected to a portion adjacent to the radially inner side of the dam portion 38 . The eaves lip 39 extends radially outward as it extends axially outward. The axially outer end, which is the tip of the eaves lip 39, is located radially inwardly of the axially inner opening of the flange through-hole 23 of the inclined surface portion 17 of the rotary flange 10. A labyrinth seal is formed by closely facing each other. In this example, the entire inclined surface portion 17 is located radially inward of the axially inner opening of the flange through-hole 23 . In addition, when carrying out the present invention, the tip portion of the eaves lip can also be made to closely face the flat portion 16 of the rotating flange 10 over the entire circumference.

In this example, the axial inner opening of the rolling element installation space 31 is closed by the combination seal ring 40 . As a result, the lubricating grease existing in the rolling element installation space 31 leaks into the external space through the axially inner opening of the rolling element installation space 31, or foreign matter such as muddy water enters the rolling element installation space 31 from the external space. to prevent intrusion.

A wheel (not shown) that constitutes a wheel and a braking rotor 27 are fitted onto the pilot portion 12 and coupled and fixed to the rotary flange 10 . More specifically, the braking rotor 27 is fitted onto the axially inner portion of the pilot portion 12 . The wheel is fitted over the axially outer portion of the pilot portion 12 . In this state, the hub bolts 13 press-fitted into the mounting holes 11 provided in the rotary flange 10 are inserted into the through holes 28 provided in the radially intermediate portion of the braking rotor 27 and the radially intermediate portion of the wheel. A hub nut (not shown) is screwed onto the axially outer end of the hub bolt 13 while the hub bolt 13 is inserted from the axially inner side through a through hole provided in the hub bolt 13, thereby connecting and fixing the wheel and the braking rotor 27 to the rotary flange 10. do.

Hub bolts inserted from the outside in the axial direction through through holes provided in the radially intermediate portion of the wheel and through holes 28 provided in the radially intermediate portion of the braking rotor 27 are attached to the rotary flange 10. The wheel and braking rotor 27 can also be fixedly coupled to the rotary flange 10 by screwing into the provided mounting hole 11 .

The braking rotator 27, which is preferably applied to the hub unit bearing of this embodiment, functions as a drainage part at each location aligned with the flange through-hole 23 of the rotary flange 10 in a state of being coupled and fixed to the rotary flange 10. It has a rotor through-hole 29 that penetrates in the axial direction. In this example, the rotor through-hole 29 is arranged coaxially with the flange through-hole 23 and has an inner diameter equal to or slightly larger than the inner diameter of the flange through-hole 23. It is In the example shown in FIGS. 1 and 2, the inner diameter of rotor through-hole 29 is slightly larger than the inner diameter of flange through-hole 23 . It should be noted that any shape can be adopted for the drainage part such as the rotor through-hole provided in the braking rotating body, as long as the drainage function can be ensured.

According to the hub unit bearing 1 of the present invention, when the vehicle is stopped after running in the rain, moisture such as muddy water adhering to the axial inner surface of the rotary flange 10 is removed from the portion between the outer seal ring 5 and the hub 3. In addition, even when the axial thickness of the rotary flange 10 is reduced, the durability of the rotary flange can be easily ensured. This point will be described in detail below.

4(A) and 4(B) are views of the upper half of the hub 3 to which the hub bolt 13 is attached, viewed from the axial inner side. Specifically, FIG. 4(B) shows a state in which the hub 3 stops rotating at the rotational position where the hole 23 is positioned at the highest position in the vertical direction, and FIG. has stopped rotating.

In the state shown in FIG. 4A, the water adhering to the axial inner surface of the thin portion 22 flows downward along the axial inner surface of the thin portion 22 as indicated by an arrow α1, for example. Alternatively, after flowing downward along the axial inner surface of the thin portion 22 as indicated by the arrow α2, the axial inner surface of the thick portion 21 and the axial inner surface of the thin portion 22 are connected. By flowing downward along the stepped surface 41 , it reaches the axially inner opening of the flange through-hole 23 . On the other hand, the water adhering to the axial inner surface of the thick portion 21 flows downward along the axial inner surface of the thick portion 21 as indicated by an arrow β1, and then reaches the stepped portion 18. or after flowing downward along the axial inner surface of the thick portion 21 as indicated by the arrow β2, based on its own surface tension, the axial direction of the thick portion 21 By flowing downward along the circumferential side edges (ridges) of the inner surface, it reaches the axially inner opening of the flange through-hole 23 .

In the state shown in FIG. 4B, the water adhering to the axial inner surface of the thin portion 22 flows downward along the axial inner surface of the thin portion 22, as indicated by an arrow α1. or by flowing downward along the step surface 41 after flowing along the axial inner surface of the thin portion 22 as indicated by the arrow α2, or by flowing downward along the stepped surface 41 as indicated by the arrow α3, By flowing downward along the step surface 41 , it reaches the axially inner opening of the flange through-hole 23 . On the other hand, the water adhering to the axial inner surface of the thick portion 21 flows downward along the axial inner surface of the thick portion 21 as indicated by an arrow β1, and then reaches the stepped portion 18. It reaches the axially inner opening of the flange through-hole 23 by flowing downward along.

As described above, in the upper half of the hub 3 , the water adhering to the axially inner side surface of the thin portion 22 and the axially inner side surface of the thick portion 21 is removed from the axially inner side of the flange through-hole 23 . Efficiently collected in the opening. The moisture collected in this opening is discharged from the axially outer opening of the rotor through-hole 29 through the flange through-hole 23 and the rotor through-hole 29 into the space axially outside the braking rotor 27 . be. Since a part of the wheel faces the axially outer opening of the rotor through-hole 29 via an axial gap, the axially outer opening of the rotor through-hole 29 is passed through this gap. Water can be drained from the part. In particular, when the wheel of the wheel is made of an aluminum wheel, a large gap is ensured, so that water can be efficiently discharged from the axially outer opening of the rotor through-hole 29 through the gap. can. Therefore, according to the structure of this example, when the vehicle stops after running in the rain, the water adhering to the axially inner surface of the rotary flange 10 is removed from the portion between the outer seal ring 5 and the hub 3, specifically can be suppressed from reaching the sliding contact portion between the tip portion of the seal lip 37c and the flat portion 16 .

When water adhering to the axial inner surface of the thin portion 22 and the axial inner surface of the thick portion 21 crosses the stepped portion 18 in the radial direction, or the axial outer side of the braking rotor 27 When water that enters the rotor through-hole 29 and the flange through-hole 23 from the space is discharged from the axially inner opening of the flange through-hole 23, the water runs on the outer peripheral surface of the eaves lip 39. , and can be guided downward along the outer peripheral surface. Therefore, it is possible to prevent moisture from reaching the portion between the outer seal ring 5 and the hub 3 also from this aspect.

In the structure of this example, while suppressing an increase in the weight of the hub unit bearing 1 included in the unsprung weight of the vehicle, the rolling fatigue life and rigidity of the hub unit bearing 1 are improved. Even if the axial thickness of the rotary flange 10 is reduced as the distance between the rows of the rolling elements 4a and 4b is increased while the dimensions are kept constant, the flange through-holes 23 increase the durability of the rotary flange 10. , and the durability of the rotating flange 10 can be easily ensured.

[Second example of embodiment]
A second example of the embodiment of the invention will be described with reference to FIG.

In this example, the shape of the flange through-hole 23a provided in the rotary flange 10 is different from that in the first embodiment. That is, in this example, of the inner peripheral surface of the flange through-hole 23a, the inner portion of the rotary flange 10 in the radial direction, in other words, the central axis of the flange through-hole 23a of the inner peripheral surface of the flange through-hole 23a The radially inner portion of the rotating flange 10 is inclined radially inwardly of the rotating flange 10 toward the axially outer side.

In this example, such a flange through-hole 23a is a tapered hole having a central axis parallel to the central axis of the hub 3 and having an inner diameter that increases from the axially inner side toward the axially outer side. there is In other words, the inner peripheral surface of the flange through-hole 23a has a central axis parallel to the central axis of the hub 3, and is configured by a conical surface whose inner diameter increases from the axially inner side to the axially outer side. ing.

In such a structure of this example, in the upper half of the hub 3 after the vehicle has stopped, water that has entered the inside of the flange through-hole 23a through the axially inner opening of the flange through-hole 23a is removed by gravity. As a result, it becomes easier to flow axially outward along the lower portion of the inner peripheral surface of the flange through-hole 23a.

In addition, in the structure of this example, the radially inner end portion (P portion) of the axially inner opening portion of the flange through-hole 23a is positioned radially inwardly of the stepped portion 18 when viewed from the axially inner side. ing. That is, in this example, the radially inner end portion (P portion) of the axially inner opening portion of the flange through-hole 23 a is arranged on the inclined surface portion 17 positioned axially inwardly of the inner side surface of the thin portion 22 . It is A portion of the stepped portion 18 is cut out by the radially inner portion of the axially inner end portion of the flange through-hole 23a. According to the structure of this example, as indicated by arrows β1 in FIGS. can be easily taken into the inside of the flange through-hole 23a through the notched portion of . However, when implementing the structure of this example, when the flange through-hole 23a is viewed from the axially inner side, the radially inner end (P portion) of the axially inner opening of the flange through-hole 23a is A structure in contact with the step portion 18 can also be adopted.
Other configurations and effects are the same as those of the first embodiment.

In the case where the flange through-hole is formed by a circular hole as in the first embodiment, the flange through-hole is formed by drilling from the axially outer side of the rotating flange. The axially outer portion of the flange through-hole has a slightly larger diameter than the axially inner portion. Therefore, also in this case, as in the case of the second embodiment, the water that has entered the inside of the flange through-hole is caused to flow along the lower side of the inner peripheral surface of the flange through-hole by the action of gravity. It is possible to make it easier to flow outward in the axial direction.

[Third example of embodiment]
A third example of the embodiment of the invention will be described with reference to FIG.

In this example, the shape of the rotor through-hole 29a provided in the braking rotor 27 is different from the first and second examples of the embodiment. That is, in this example, of the inner peripheral surface of the rotor through-hole 29a, the inner portion in the radial direction of the braking rotor 27 (=the radial direction of the rotary flange 10), in other words, the inner peripheral surface of the rotor through-hole 29a Of these, the portion positioned radially inward of the braking rotor 27 with respect to the central axis of the rotor through-hole 29a moves radially inward of the braking rotor 27 as it goes axially outward. inclined to

In this example, such a rotor through-hole 29a is arranged coaxially with the flange through-hole 23a in a state in which the braking rotor 27 is coupled and fixed to the rotary flange 10, and extends from the axially inner side to the axially outer side. It is composed of a tapered hole whose inner diameter increases as the diameter increases. In this example, the inner peripheral surface of the flange through-hole 23a and the inner peripheral surface of the rotor through-hole 29a are arranged on the same virtual conical surface. However, when carrying out the present invention, the inner diameter of the rotor through-hole 29a can be made slightly larger than in the case of this example.

In such a structure of this example, in the upper half of the braking rotator 27 after the vehicle has stopped, moisture that has entered the inside of the rotor through-hole 29a is removed by the action of gravity on the inner circumference of the rotor through-hole 29a. It can be facilitated to flow axially outward along the underside of the face.
Other configurations and effects are the same as those of the second embodiment.

When the rotor through-hole is formed as a circular hole as in the first embodiment, the rotor through-hole can be formed by drilling from the outside of the braking rotor in the axial direction. The diameter of the axially outer portion of the rotor through-hole thus formed is slightly larger than that of the axially inner portion thereof. Therefore, also in this case, as in the case of the third embodiment, the water that has entered the inside of the rotor through-hole is caused to flow along the lower side of the inner peripheral surface of the rotor through-hole by the action of gravity. It is possible to make it easier to flow outward in the axial direction.

[Fourth example of embodiment]
A fourth example of the embodiment of the invention will be described with reference to FIG.

In this example, the shape of the flange through-hole 23b provided in the rotary flange 10 and the shape of the rotor through-hole 29b provided in the braking rotor 27 are different from those of the first embodiment. That is, in this example, the flange through-hole 23b is a circular hole that is inclined radially inward of the rotary flange 10 as it extends axially outward. The rotor through-hole 29b is a circular hole arranged coaxially with the flange through-hole 23b in a state in which the braking rotor 27 is coupled and fixed to the rotary flange 10. As shown in FIG. That is, the rotor through hole 29b is inclined radially inward of the braking rotor 27 as it extends axially outward. In this example, the inner diameter of the rotor through-hole 29b is the same size as the inner diameter of the flange through-hole 23b. However, when implementing the present invention, the inner diameter of the rotor through-hole 29b can be made slightly larger than the inner diameter of the flange through-hole 23b.

In such a structure of this example, in the upper half of the rotating flange 10 and the braking rotor 27 after the vehicle stops, the moisture that has entered the inside of the flange through-hole 23b and the rotor through-hole 29b is removed by the action of gravity. , along the lower side portions of the inner peripheral surfaces of the flange through-hole 23b and the rotor through-hole 29b, it is possible to make it easier to flow outward in the axial direction.
Other configurations and effects are the same as those of the first embodiment.

[Fifth example of embodiment]
A fifth example of the embodiment of the present invention will be described with reference to FIG.

In this example, the shape of the drainage portion provided in the braking rotor 27 is different from that in the first embodiment. That is, in the first example of the embodiment, the rotor through-hole 29 that axially penetrates the braking rotor 27 is used as the drainage portion provided in the braking rotor 27 . On the other hand, in the present example, as the drainage portion provided in the braking rotor 27, the drain portion penetrates the braking rotor 27 in the axial direction and is open to the inner peripheral surface of the braking rotor 27. An elongated notch 42 is employed. The radially outer end of the notch 42 is aligned with the flange through-hole 23 when the braking rotor 27 is coupled and fixed to the rotary flange 10 .
Other configurations and effects are the same as those of the first embodiment.

The present invention can be carried out by appropriately combining the structures of the above-described embodiments within a range that does not cause contradiction.

Reference Signs List 1 hub unit bearing 2 outer ring 3 hub 4a, 4b rolling element 5 outer seal ring 6a, 6b outer ring raceway 7 stationary flange 8 support hole 9a, 9b inner ring raceway 10 rotating flange 11 mounting hole 12 pilot portion 13 hub bolt 14 root portion 15 thickness Changed portion 16 Flat portion 17 Slanted surface portion 18 Stepped portion 19 Curved surface portion 20 Cylindrical surface portion 21 Thick portion 22 Thin portion 23, 23a, 23b Flange through hole 24 Hub wheel 25 Inner ring 26 Spline hole 27 Braking rotor 28 Through hole 29, 29a, 29b rotor through hole 30a, 30b retainer 31 rolling element installation space 32 core metal 33 sealing material 34 fitting cylinder portion 35 upright plate portion 36 support plate portion 37a, 37b, 37c seal lip 38 weir portion 39 eaves lip 40 combination Seal ring 41 step surface (circumferential direction end)
42 Notch

Claims (2)

an outer ring having a double-row outer ring raceway on its inner peripheral surface;
It has a double-row inner ring raceway on the outer peripheral surface, and a rotating flange projecting radially outward at a portion located axially outside the outer ring, and the rotating flange is provided at a plurality of positions in the circumferential direction. a hub having a mounting hole for inserting the hub bolt;
a plurality of rolling elements arranged for each row between the double-row outer ring raceway and the double-row inner ring raceway;
an outer seal ring that is attached to the axially outer end of the outer ring and closes the axially outer opening of the rolling element installation space that exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub; prepared,
The rotating flange has a radially inner portion, a root portion whose axial thickness does not change in the circumferential direction, and a radially outer portion, which has a wall thickness changing portion whose axial thickness changes in the circumferential direction. and the axially inner surface of the root portion and the axially inner surface of the thickness change portion are connected by a radially outwardly directed stepped portion provided at the root portion,
The thickness change portion includes a plurality of thick portions each extending in a radial direction from the root portion and having the mounting holes, and a plurality of thick portions connecting the thick portions adjacent to each other in the circumferential direction. and an axial inner surface of the thin portion is arranged axially outside the axial inner surface of the thick portion,
The rotating flange has a flange through-hole axially penetrating through each of radially inner ends of a portion sandwiched between the thick-walled portions adjacent in the circumferential direction. The radially inner end of the axially inner opening is in contact with the stepped portion, or is positioned radially inwardly of the stepped portion, when viewed from the axially inner side.
hub unit bearings. Of the inner peripheral surface of the flange through-hole, the radially inner portion of the rotary flange is inclined radially inward of the rotary flange as it extends axially outward,
A hub unit bearing according to claim 1.

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