JP7294042B2 - hub unit bearing - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hub unit bearing for rotatably supporting wheels and braking rotors of an automobile with respect to a suspension system.

A vehicle wheel and a braking rotator are rotatably supported with respect to a suspension system by hub unit bearings. A hub unit bearing includes 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 rolling elements between the double-row outer ring raceway and the double-row inner ring raceway. and a plurality of movably arranged rolling elements. The hub unit bearing further includes a pair of sealing devices that seal openings on both sides in the axial direction 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. This prevents foreign matter such as muddy water from entering the rolling element installation space from the external space, and prevents grease sealed in the rolling element installation space from leaking into the external space. Of the pair of sealing devices, the axially outer sealing device that closes the axially outer opening of the rolling element installation space is composed of a seal ring having at least one seal lip in sliding contact with the outer peripheral surface of the hub. be done.

The hub unit bearing as described above is used in an environment where it is exposed to the external space, and is also affected by heat conduction from the braking rotor supported by the hub. For this reason, temperature changes during use are large, and as a result, pressure (internal pressure) in the rolling element installation space tends to change greatly, and the rotational torque of the hub unit bearing (the rotational torque of the hub relative to the outer ring) tends to increase. Fluctuations can also be large.

That is, when the internal pressure of the rolling element installation space becomes excessively high due to the temperature rise of the hub unit bearing, air leaks into the external space through the sliding contact portion between the seal lip of the seal ring and the outer peripheral surface of the hub. Sometimes. In this way, when the air in the rolling element installation space leaks to the external space, the pressure in the rolling element installation space becomes negative (lower than the atmospheric pressure) when the temperature of the hub unit bearing decreases. low pressure). As a result, the seal lip sticks to the outer peripheral surface of the hub, thereby increasing the sliding resistance (seal torque) of the seal lip with respect to the outer peripheral surface of the hub, thereby increasing the rotational torque of the hub unit bearing.

Japanese Patent Laying-Open No. 2010-38250 (Patent Document 1) describes a hub unit bearing in which a gas flow passage is formed so as to penetrate an outer ring in the radial direction, and a gas valve is installed at an opening of the gas flow passage on the outer space side. It is According to the hub unit bearing disclosed in Japanese Patent Application Laid-Open No. 2010-38250, the opening/closing state of the gas valve can be adjusted according to the pressure change in the internal space, so the pressure in the internal space can be kept constant.

Japanese Unexamined Patent Application Publication No. 2010-38250 Japanese Utility Model Laid-Open No. 4-42971

In the hub unit bearing disclosed in Japanese Patent Laying-Open No. 2010-38250, the gas valve is constructed by elastically urging a valve body that closes the gas flow passage with a spring member. Therefore, it is necessary to attach the gas valve to an outer ring or a cap that is internally fitted and fixed to the axially inner end of the outer ring, on which the centrifugal force due to the rotation of the wheel does not act during use (while the automobile is running). However, when the gas valve is attached to the outer ring or the cap, foreign matter such as muddy water may enter the internal space through the gas valve while the gas valve is open.

Japanese Utility Model Laid-Open No. 4-42971 (Patent Document 2) describes a filter (air breather) that allows air to pass through while removing foreign matter such as dust and water as a technique related to the present invention.

SUMMARY OF THE INVENTION In view of the circumstances described above, the present invention realizes a structure of a hub unit bearing that can maintain a constant pressure in the internal space and prevent foreign matter from entering the internal space. It is intended to

A hub unit bearing of the present invention comprises an outer ring, a hub, a plurality of rolling elements, a seal ring, a cap, and a valve device.
The outer ring has a double-row outer ring raceway on its inner peripheral surface, and is supported and fixed to the suspension system and does not rotate.
The hub has a hub-side through hole axially penetrating through the central portion thereof, and has a double-row inner ring raceway on an outer peripheral surface, and a wheel is fixed and rotates together with the wheel.
The plurality of rolling elements are rotatably arranged between the double-row outer ring raceway and the double-row inner ring raceway.
The seal ring 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.
The cap is fitted to the axially inner end of the outer ring and closes the axially inner opening of the outer ring.
The valve device has a pair of elastic members.
The pair of elastic members has through holes axially penetrating through positions that are not aligned with each other, and includes flat plate portions whose axial side surfaces are in contact with each other, and radially outer ends of the flat plate portions. and inclined plate portions extending in directions away from each other as they go radially outward and fitted inside the inner peripheral surfaces of the hub-side through holes .

The first elastic member of the pair of elastic members further includes a first engaging portion at a position radially out of the central axis of the flat plate portion of the first elastic member, and A second elastic member of the pair of elastic members may further include a second engaging portion that engages with the first engaging portion in a concave-convex manner.

In the valve device, the pair of elastic members having the same shape are arranged symmetrically with respect to an imaginary plane perpendicular to the central axis of the hub, and in phase with respect to the circumferential direction of the through holes of the pair of elastic members. can be configured by combining them in a mutually shifted state.

One elastic member of the pair of elastic members further includes a shaft portion projecting from the flat plate portion toward the other elastic member of the pair of elastic members, and The elastic member may further include a fitting hole into which the shaft portion is fitted.

The hub unit bearing of the present invention further comprises a cover fitted inside a portion of the inner peripheral surface of the hub-side through hole that is axially outward of the portion where the sealing device is provided, and the cover: It can have a bottom plate portion including at least one vent hole axially penetrating therethrough, and a fitting plate portion axially bent from a radially outer end of the bottom plate portion.

According to the hub unit bearing of the present invention, it is possible to keep the pressure in the internal space constant and prevent foreign matter from entering the internal space.

FIG. 1 is a cross-sectional view showing a hub unit bearing according to a first example of the embodiment. FIG. 2 is an enlarged view of part X in FIG. 3 is an enlarged view of the lower portion of FIG. 2; FIG. FIG. 4 is a view similar to FIG. 2, exaggerating the state in which the internal space has increased pressure; FIG. 5 is a cross-sectional view showing a hub unit bearing according to a second example of the embodiment. 6 is an enlarged view of the Y portion of FIG. 5. FIG. FIG. 7 is a diagram corresponding to FIG. 2, showing a third example of the embodiment.

[First example of embodiment]
1 to 4 show a first example of an embodiment of the invention. A hub unit bearing 1 of this example is for a driven wheel, and includes an outer ring 2, a hub 3, a plurality of rolling elements 4, a seal ring 5, a cap 6, and a valve device 7.

The outer ring 2 is made of hard metal such as medium carbon steel. The outer ring 2 has double-row outer ring raceways 8a and 8b on its inner peripheral surface, and a stationary flange 9 protruding radially outward at its axial intermediate portion. The stationary flange 9 has support holes 10 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 support bolts inserted through support holes 10 of the stationary flange 9, and does not rotate even when the wheel rotates.

The hub 3 has double-row inner ring raceways 11a and 11b on its outer peripheral surface, and is arranged coaxially with the outer ring 2 radially inward of the outer ring 2 . The hub 3 has a rotating flange 12 protruding radially outward at a portion located axially outside the axially outer end of the outer ring 2, and has a cylindrical shape at the axially outer end. It has a shaped pilot portion 13 . The rotating flange 12 has mounting holes 14 that penetrate in the axial direction at a plurality of locations in the circumferential direction of the radially intermediate portion.

"Outside" with respect to the axial direction refers to the left side in FIGS. 1 to 7, which is the outside of the vehicle body when the hub unit bearing 1 is assembled to the automobile. On the contrary, the right side in FIGS. 1 to 7, which is the center side of the vehicle body when the hub unit bearing 1 is assembled to the automobile, is referred to as "inside" with respect to the axial direction.

The hub 3 has a center hole 15 extending axially through the hub 3 , and a partition wall 16 protruding radially inward from an axially intermediate portion of the inner peripheral surface of the center hole 15 . The hub 3 further has an engaging hole 17 axially penetrating through the central portion of the partition wall portion 16 . In other words, the hub 3 has an inward flange-shaped partition wall portion 16 that protrudes radially inward from an axially intermediate portion of the center hole 15 , and the inner peripheral surface of the partition wall portion 16 serves as an engagement hole. 17. The engagement hole 17 is formed by connecting a large-diameter portion 18 in the axially intermediate portion and small-diameter portions 19 on both sides in the axial direction by a stepped portion 20 .

The hub 3 has an inclined surface portion 21 , which is inclined in a direction in which the inner diameter increases toward the axially outer side, in a portion of the inner peripheral surface of the central hole 15 located axially outside the partition wall portion 16 . In this example, the inclined surface portion 21 is located radially inside the rotary flange 12 . Further, in this example, the inclined surface portion 21 is configured by a truncated cone surface having a linear generatrix shape. However, the inclined surface portion 21 can also be configured by a curved surface having a curved generatrix shape such as an arc.

The hub 3 of this example is formed by combining an inner ring 22 and a hub body 23 .

The inner ring 22 is made of hard metal such as bearing steel. The inner ring 22 has the axially inner inner ring raceway 11a of the double-row inner ring raceways 11a and 11b on its outer peripheral surface.

The hub body 23 is made of hard metal such as medium carbon steel. The hub body 23 has the axially outer inner ring raceway 11b of the double-row inner ring raceways 11a and 11b in the axially intermediate portion of the outer peripheral surface. The hub body 23 has a rotary flange 12 protruding radially outward at a portion located axially outside the inner ring raceway 11b on the axially outer side, and has a cylindrical shape at the axially outer end. has a pilot portion 13 of . The hub body 23 has a center hole 15 that extends axially through the hub body 23 , and a partition wall portion 16 that protrudes radially inward from an axially intermediate portion of the inner peripheral surface of the center hole 15 . The hub body 23 further has an engaging hole 17 axially penetrating through the central portion of the partition wall portion 16 .

The hub main body 23 has a fitting tubular portion, which has a smaller outer diameter than the portion adjacent to the axially outer side and is positioned axially inwardly of the axially outer inner ring raceway 11b, into which the inner ring 22 is fitted. 24. The hub body 23 further has a crimped portion 25 that bends radially outward from the axially inner end of the fitting tube portion 24 and presses the axially inner end surface of the inner ring 22 . That is, in the hub 3 of this example, in a state in which the inner ring 22 is externally fitted to the fitting tubular portion 24 of the hub main body 23, the stepped surface 26 present at the axially outer end portion of the fitting tubular portion 24 and the caulked portion 25, the inner ring 22 is sandwiched from both sides in the axial direction, and the inner ring 22 and the hub body 23 are connected and fixed.

A plurality of each of the rolling elements 4 are arranged between the double-row outer ring raceways 8a, 8b and the double-row inner ring raceways 11a, 11b while being held by retainers 57a, 57b so as to be free to roll. It is Thereby, the hub 3 is rotatably supported radially inwardly of the outer ring 2 . Although balls are used as the rolling elements 4 in this example, tapered rollers may be used instead of the balls. In this example, the pitch diameter of the rolling elements 4 in the axially inner row and the pitch diameter of the rolling elements 4 in the axially outer row are the same. It can also be applied to a different diameter PCD type hub unit bearing in which the pitch circle diameter of the moving body and the pitch circle diameter of the rolling elements in the axially outer row are different from each other.

The seal ring 5 is present between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3, and is an axially outer opening of a substantially cylindrical rolling element installation space 27 in which the rolling elements 4 are arranged. block the The seal ring 5 includes a metal core 28 and a seal material 29 .

The cored bar 28 is formed into an annular shape as a whole by bending a metal plate such as a mild steel plate. The core bar 28 is internally fitted and fixed to the axially outer end portion of the outer ring 2 .

The sealing material 29 is made of an elastic material such as an elastomer such as rubber, and is supported and fixed to the metal core 28 by vulcanization adhesion. The sealing member 29 has at least one (two in the illustrated example) sealing lips 30 . The end portion of the seal lip 30 is in sliding contact with the axial intermediate portion of the outer peripheral surface of the hub 3 or the axial inner surface of the rotary flange 12 over the entire circumference. The seal member 29 of this example has a labyrinth lip 31 in a portion of the seal lip 30 that is located radially outside of the radially outermost seal lip. The tip of the labyrinth lip 31 is closely opposed to the axial inner surface of the rotary flange 12 .

The cap 6 is fitted to the axially inner end of the outer ring 2 and closes the axially inner opening of the outer ring 2 . The cap 6 is configured in a bottomed cylindrical shape as a whole. That is, the cap 6 includes a cylindrical fitting tube portion 32 fitted inside the axially inner end portion of the outer ring 2 and a fitting tube portion 32 that is bent radially inward from the axially inner end portion of the fitting tube portion 32 . and a bottom plate portion 33 that closes the axially inner opening of the fitting cylinder portion 32 .

The valve device 7 includes a pair of elastic members 34 a and 34 b each made of an elastic material such as an elastomer such as rubber, and fitted to the inner peripheral surface of the hub 3 . The valve device 7 is located radially inward of the outer ring 2 and is provided between an internal space 38 including the rolling element installation space 27 and an external space, the axially inner opening of which is closed by the cap 6 . to seal. In this example, the valve device 7 is fitted in the large diameter portion 18 of the inner peripheral surface of the engaging hole 17 of the hub 3 .

The pair of elastic members 34a and 34b has through holes 35a and 35b axially penetrating through positions that are not aligned with each other. Slanted plate portions 37a and 37b are provided, respectively, extending in directions away from each other as they go radially outward from the radially outer ends of the portions 36a and 36b and fitted inside the inner peripheral surface of the hub 3 . That is, each of the pair of elastic members 34a and 34b is configured in the shape of a truncated cone with an open bottom or in the shape of a dish.

The flat plate portions 36a, 36b have a disk shape, and the inclined plate portions 37a, 37b have a truncated cone shape. In addition, the valve device 7 includes the pair of elastic members 34a and 34b with the flat plate portions 36a and 36b of the pair of elastic members 34a and 34b having opposite axial side surfaces facing each other. In a free state before being internally fitted, it has an axial dimension larger than the axial dimension of the large diameter portion 18 (the interval between the stepped portions 20 facing each other) and is larger than the inner diameter dimension of the large diameter portion 18 have a large outer diameter. In short, in the valve device 7, the inclined plate portions 37a and 37b of the pair of elastic members 34a and 34b are internally fitted to the large diameter portion 18 with interference. In addition, FIG. 3 shows the shape of the inclined plate portions 37a and 37b in a free state.

In this example, the pair of elastic members 34a, 34b have the same shape. That is, the valve device 7 is arranged such that the pair of elastic members 34a and 34b are arranged symmetrically with respect to a virtual plane perpendicular to the central axis of the hub 3, and the through holes 35a and 35b are out of phase with each other in the circumferential direction. The axial side surfaces of the flat plate portions 36a and 36b facing each other are butted against each other and combined.

Specifically, of the pair of elastic members 34a and 34b, the flat plate portion 36a of the inner elastic member 34a in the axial direction has a through hole axially penetrating therethrough at one position in the circumferential direction radially off the center. 35a. The axially outer opening of the through hole 35a is closed by the axially inner side surface of the flat plate portion 36b of the axially outer elastic member 34b. The inclined plate portion 37a of the axially inner elastic member 34a has its outer peripheral surface fitted into the large-diameter portion 18 of the engagement hole 17 of the hub 3, and its radially outer end is attached to the axially inner side. It abuts against the step portion 20 elastically. Incidentally, in this example, the center hole 15 and the engaging hole 17 correspond to the hub-side through hole described in the claims. However, the hub unit bearing of the present invention can also be applied to a structure that does not have a partition. In this case, the inclined plate portion of the elastic member is fitted in the center hole.

Of the pair of elastic members 34a and 34b, the flat plate portion 36b of the axially outer elastic member 34b is provided with an axially penetrating through hole 36b at a position radially opposite to the through hole 35a of the axially inner elastic member 34a. It has a hole 35b. The axially inner opening of the through hole 35b is closed by the axially outer surface of the flat plate portion 36a of the axially inner elastic member 34a. The inclined plate portion 37b of the axially outer elastic member 34b has its outer peripheral surface fitted into the large diameter portion 18 of the engagement hole 17 of the hub 3, and its radially outer end It abuts against the step portion 20 elastically.

A braking rotating body 39 such as a disk or drum and a wheel 40 constituting a wheel are supported and fixed to the rotation flange 12 of the hub 3 of the hub unit bearing 1 using a plurality of hub bolts 41 .

The braking rotor 39 has a center hole 42 and through holes 43 axially penetrating at a plurality of locations in the circumferential direction.

The wheel 40 has a center hole 44 and through holes 45 axially penetrating at a plurality of locations in the circumferential direction.

The braking rotator 39 and the wheel 40 are arranged such that the center hole 42 of the braking rotator 39 and the center hole 44 of the wheel 40 are fitted onto the pilot portion 13 of the hub 3, and the through hole of the braking rotator 39 is fitted. 43 and hub bolts 41 inserted through the through holes 45 of the wheel 40 are screwed into the attachment holes 14 of the rotary flange 12 to be supported and fixed to the rotary flange 12 .

However, by press-fitting a stud into the mounting hole of the rotating flange, inserting the through hole of the braking rotor and the through hole of the wheel into the stud, and screwing the hub nut onto the stud, the braking rotor and The wheel can also be fixedly connected to the rotating flange.

When the pressure in the internal space 38 (internal pressure) becomes higher than the pressure in the external space (atmospheric pressure) as the temperature of the hub unit bearing 1 rises, as shown in FIG. , 34b, the flat plate portion 36a of the axially inner elastic member 34a is pushed outward in the axial direction, and is elastically deformed so as to curve. When the flat plate portion 36a of the axially inner elastic member 34a is elastically deformed, at least a part of the axially outer opening portion of the through hole 35a provided in the flat plate portion 36a is replaced by the flat plate portion 36b of the axially outer elastic member 34b. from the axial inner surface of the Further, when the flat plate portion 36a of the axially inner elastic member 34a is elastically deformed so as to be curved, the flat plate portion 36b of the axially outer elastic member 34b is pushed outward in the axial direction, and the flat plate portion 36b is provided with the flat plate portion 36b. At least part of the axially inner opening of the through hole 35b is separated from the axially outer side surface of the flat plate portion 36a of the axially inner elastic member 34a. As a result, an air passage is secured (opening) that communicates the internal space 38 existing axially inside the axially inner elastic member 34a and the external space existing axially outside the axially outer elastic member 34b. do). The air in the internal space 38 is discharged to the external space through this ventilation path, so that the pressure in the internal space 38 is reduced to the same as the pressure in the external space.

On the other hand, when the pressure in the internal space 38 becomes negative as the temperature of the hub unit bearing 1 decreases, the flat plate portion 36b of the elastic member 34b on the axially outer side is pushed axially inward. is elastically deformed so as to curve, and the flat plate portion 36a of the axially inner elastic member 34a is pushed axially inward. As a result, at least a part of the axially inner opening of the through hole 35b provided in the flat plate portion 36b of the axially outer elastic member 34b is aligned with the axially outer surface of the flat plate portion 36a of the axially inner elastic member 34a. and at least a portion of the axially outer opening of the through hole 35a provided in the flat plate portion 36a of the axially inner elastic member 34a is aligned with the axis of the flat plate portion 36b of the axially outer elastic member 34b. away from the directional inner surface. As a result, a ventilation path is secured to communicate the internal space 38 and the external space, and air is supplied from the external space to the internal space 38 through this ventilation path, thereby increasing the pressure in the internal space 38 and increasing the external pressure. equal to the pressure in space.

When the pair of elastic members 34a and 34b are elastically deformed as the pressure in the internal space 38 changes, the volume of the annular space existing between the inclined plate portions 37a and 37b decreases, and the pressure in the annular space increases. Rise. When the air passage connecting the inner space 38 and the outer space is secured while the pressure in the annular space is increased, the pump action causes the air to pass through the air passage with force. As a result, the pressure difference between the internal space 38 and the external space can be eliminated quickly.

As described above, according to the hub unit bearing 1 of the present embodiment, the valve device 7 arranged between the internal space 38 and the external space opens and closes according to the pressure change in the internal space 38 . Therefore, the pressure in the inner space 38 can be kept the same as the pressure in the outer space. In other words, the pressure in the internal space 38 can be kept constant. Since the valve device 7 is open and the air passage communicating between the internal space 38 and the external space is secured for only a short time, it is difficult for foreign matter to enter the internal space 38 through the air passage.

Further, the valve device 7 is attached to an axially intermediate portion of the inner peripheral surface of the hub 3 . That is, the valve device 7 is arranged at a position some distance from the axially outer opening of the hub 3 . Therefore, even if foreign matter such as muddy water is thrown up by the wheels and adheres to the periphery of the pilot portion 13 , the foreign matter does not easily reach the valve device 7 . Also from this aspect, entry of foreign matter into the internal space 38 can be suppressed.

The valve device 7 of this example is composed only of a pair of elastic members 34a and 34b. Therefore, the valve device 7 of this example can be made lighter than the gas valve described in Japanese Patent Application Laid-Open No. 2010-38520.

In particular, the valve device 7 of this example is formed by combining a pair of elastic members 34a and 34b having the same shape. Therefore, according to this example, the parts management and assembly work of the valve device 7 can be facilitated, and the cost can be suppressed.

The valve device 7 of this example does not use a spring member unlike the gas valve described in JP-A-2010-38520. Therefore, as described above, the valve device 7 of this example can be attached to the inner peripheral surface of the hub 3 that rotates together with the wheel during use. Foreign matter such as muddy water adhering to the surface of the hub 3 moves radially outward due to the action of centrifugal force associated with the rotation of the wheel. can be reduced. Therefore, according to the hub unit bearing 1 of this example, even when the valve device 7 is open, entry of foreign matter into the internal space 38 can be suppressed.

In particular, the hub 3 of the hub unit bearing 1 of this embodiment is inclined in a direction in which the inner diameter increases toward the axially outer side in a portion of the inner peripheral surface of the center hole 15 that is positioned axially outwardly of the partition wall portion 16 . It has an inclined surface portion 21 with a curved surface. Therefore, when the hub 3 rotates together with the wheel, the foreign matter adhering to the inner peripheral surface of the hub 3 is directed radially outward and axially outward along the inclined surface portion 21 by the action of the centrifugal force, and moves toward the mounting position of the valve device 7. move away from. Therefore, according to the hub unit bearing 1 of this example, it is possible to more effectively prevent foreign matter from entering the internal space 38 .

[Second example of embodiment]
5 and 6 show a second example of an embodiment of the invention. The valve device 7a includes a pair of elastic members 34c and 34d. A pair of elastic members 34c and 34d are provided with inclined plate portions 37c and 37d having arcuate cross-sectional shapes. As a result, the outer diameter dimension of the valve device 7a (inclined plate portions 37c and 37d) in the free state before the valve device 7a is internally fitted in the large diameter portion 18 of the inner peripheral surface of the engagement hole 17 is is larger than the outer diameter dimension of the valve device 7 (inclined plate portions 37a and 37b) in the free state of the first example of the form of . That is, in this example, the interference of the valve device 7a with respect to the large diameter portion 18 is made larger than the interference of the valve device 7 with respect to the large diameter portion 18 according to the first example of the embodiment.

Therefore, according to the valve device 7a of this example, it is possible to prevent the pair of elastic members 34c and 34d from rotating relative to each other. Specifically, the pair of elastic members 34 c and 34 d relatively rotate in the direction in which the through holes 35 a and 35 b approach each other, and the through holes 35 a and 35 b overlap in the axial direction so that regardless of the pressure in the internal space 38 . , the internal space 38 and the external space are communicated with each other to prevent foreign matter from entering easily.

Further, in this example, the pair of elastic members 34c and 34d are provided with axially protruding engaging convex portions 46a and 46b and axially recessed engaging portions 46a and 46b on the axial side surfaces of the flat plate portions 36c and 36d facing each other. It further includes recesses 47a and 47b.

Specifically, of the pair of elastic members 34c and 34d, the axially inner elastic member 34c protrudes axially outward to a portion of the flat plate portion 36c located radially inward of the through hole 35a. It has an engaging convex portion 46a, and an engaging concave portion 47a is provided in a portion located on the opposite side in the radial direction of the engaging convex portion 46a.

Of the pair of elastic members 34c and 34d, the axially outer elastic member 34d has an engaging projection protruding axially inward on a portion of the flat plate portion 36d located radially inward of the through hole 35b. An engaging concave portion 47b is provided in a portion having the portion 46b and located radially opposite to the engaging convex portion 46b.

That is, in this example, the pair of elastic members 34c and 34d have the same shape.

In the valve device 7a of the present embodiment, the pair of elastic members 34c and 34d are engaged with the engaging convex portion 46a of the axially inner elastic member 34c and the engaging concave portion 47b of the axially outer elastic member 34d. In addition, in a state in which the engaging concave portion 47a of the axially inner elastic member 34c and the engaging convex portion 46b of the axially outer elastic member 34d are engaged with each other, the side surfaces of the flat plate portions 36c and 36d facing each other It is configured by matching and combining them.

That is, in the present example, the axially inner elastic member 34c corresponds to the first elastic member, and each of the engaging convex portion 46a and the engaging concave portion 47a of the axially inner elastic member 34c corresponds to the first elastic member. corresponds to the engaging portion of Further, the axially outer elastic member 34d corresponds to a second elastic member, and each of the engaging convex portion 46b and the engaging concave portion 47b of the axially outer elastic member 34d is the second engaging portion. corresponds to

In the valve device 7a of the present embodiment, the engaging convex portion 46a of the axially inner elastic member 34c and the engaging concave portion 47b of the axially outer elastic member 34d are engaged in concave-convex engagement, and the axially inner elastic member Since the engagement concave portion 47a of the elastic member 34c and the engagement convex portion 46b of the axially outer elastic member 34d are engaged with each other, the pair of elastic members 34c and 34d are more reliably prevented from rotating relative to each other. can be done. Therefore, according to this example, it is possible to more effectively prevent foreign matter from easily entering the internal space 38 .

In this example, the pair of elastic members 34c and 34d includes one each of engaging projections 46a and 46b and engaging recesses 47a and 47b. Other configurations are possible. Specifically, for example, of the pair of elastic members, the first elastic member has one or more engagement projections in the circumferential direction, and the second elastic member has one or more engagement projections in the circumferential direction. It is possible to adopt a structure in which an engagement concave portion is provided at a location. However, in order to make the pair of elastic members have the same shape in order to reduce the cost, as in this example, the pair of elastic members 34c and 34d are arranged on opposite sides of each other in the radial direction. It is preferable to have a structure including one each of 46a, 46b and one engaging recess 47a, 47b.

Further, in this example, the pair of elastic members 34c and 34d are arranged radially inward of the through holes 35a and 35b in the flat plate portions 36c and 36d. However, the positional relationship in the radial direction between the through hole and the engaging protrusions and engaging recesses may be reversed. Furthermore, in this example, the phases of the through holes 35a, 35b, the engaging protrusions 46a, 46b, and the engaging recesses 47a, 47b are matched in the circumferential direction. It is also possible to have different phases in the circumferential direction from the engaging recesses.

Further, the hub unit bearing 1a of this example includes a cover 48 fitted inside a portion of the inner peripheral surface of the hub 3 that is axially outside the portion where the valve device 7a is mounted. The cover 48 includes a disk-shaped bottom plate portion 49 and a cylindrical fitting tube portion 50 .

The bottom plate portion 49 has at least one air hole 51 extending therethrough in the axial direction. In this example, the bottom plate portion 49 has vent holes 51 axially penetrating therethrough at a plurality of circumferentially equidistant locations in the radially outer portion, that is, in the vicinity of the fitting tube portion 50 .

The fitting tube portion 50 is axially bent from the radially outer end portion of the bottom plate portion 49 and fitted to the inner peripheral surface of the hub 3 .

Since the hub unit bearing 1a of this example includes the cover 48, it is possible to prevent foreign matter such as muddy water adhering to the inner peripheral surface of the hub 3 from reaching the valve device 7a. Intrusion can be prevented more effectively. Other configurations and effects are the same as those of the first embodiment.

[Third example of embodiment]
FIG. 7 shows a third example of an embodiment of the invention. The valve device 7b of this example includes a pair of elastic members 34e and 34f.

Of the pair of elastic members 34e and 34f, the axially inner elastic member 34e has a shaft portion 52 protruding axially outward from the central portion of the axial outer surface of the flat plate portion 36e. The shaft portion 52 includes an axially inner small diameter portion 53 , an axially outer large diameter portion 54 , and a stepped portion 55 connecting the outer peripheral surface of the small diameter portion 53 and the outer peripheral surface of the large diameter portion 54 .

Of the pair of elastic members 34e and 34f, the axially outer elastic member 34f has a fitting hole 56 axially penetrating through it in the central portion of the flat plate portion 36f.

In the valve device 7b of this example, the pair of elastic members 34e and 34f are inserted into the fitting hole 56 of the axially outer elastic member 34f. It is configured by combining the opposed side surfaces of the flat plate portions 36e and 36f in a fitted state. When the pair of elastic members 34e and 34f are combined with the opposing side surfaces of the flat plate portions 36e and 36f, the axially outer flat plate portion 36f is positioned between the stepped portion 55 of the shaft portion 52 and the axially inner side. is elastically sandwiched between the flat plate portion 36e and the axially outer side surface of the flat plate portion 36e. Therefore, before the valve device 7b is attached to the inner peripheral surface of the hub 3, the pair of elastic members 34e and 34f can be temporarily assembled so as not to be inadvertently separated. Therefore, the operation of attaching the valve device 7b to the inner peripheral surface of the hub 3 can be facilitated, and the operation of shifting the phases of the through holes 35a and 35b of the pair of elastic members 34e and 34f in the circumferential direction with respect to each other. can improve the quality.

When combining the pair of elastic members 34e and 34f, the shaft portion 52 of the axially inner elastic member 34e is fitted with the axially outer elastic member 34f while the large diameter portion 54 is elastically reduced in diameter. The small diameter portion 53 of the shaft portion 52 is arranged radially inside the fitting hole 56, and the large diameter portion 54 is elastically restored.

In this example, a structure in which the axially inner elastic member 34e includes the shaft portion 52 and the axially outer elastic member 34f includes the fitting hole 56 has been described. It is also possible to adopt a structure in which a joint hole is provided and the axially outer elastic member is provided with a shaft portion. Other configurations and effects are the same as those of the first embodiment.

The structures of the first to third examples of the embodiment described above can be combined as appropriate and carried out as long as there is no contradiction. Specifically, for example, as in the third example of the embodiment, one elastic member of a pair of elastic members has a shaft portion, and the other elastic member fits inside the shaft portion. As in the second example of the embodiment, it is possible to combine the structure having the fitting hole with the structure having the concave-convex engaging portion for preventing the pair of elastic members from rotating relative to each other.

Further, the hub unit bearing of the present invention may be combined with a filter (air breather) that allows air to pass through while removing foreign matter such as dust and water, as described in Japanese Utility Model Laid-Open No. 4-42971. can. That is, the filter can be attached to the axially inner opening of the through hole of the axially inner elastic member of the pair of elastic members of the valve device. According to such a configuration, it is possible to more effectively prevent foreign matter from entering the internal space.

REFERENCE SIGNS LIST 1 hub unit bearing 2 outer ring 3 hub 4 rolling element 5 seal ring 6 cap 7 valve device 8a, 8b outer ring raceway 9 stationary flange 10 support hole 11a, 11b inner ring raceway 12 rotating flange 13 pilot portion 14 mounting hole 15 center hole 16 partition wall portion 17 engagement hole 18 large diameter portion 19 small diameter portion 20 stepped portion 21 inclined surface portion 22 inner ring 23 hub body 24 fitting cylindrical portion 25 crimped portion 26 stepped surface 27 rolling element installation space 28 core metal 29 seal material 30 seal lip 31 labyrinth lip 32 fitting tube portion 33 bottom plate portion 34a, 34b, 34c, 34d, 34e, 34f elastic member 35a, 35b through hole 36a, 36b, 36c, 36d, 36e, 36f flat plate portion 37a, 37b, 37c, 37d inclined plate portion 38 Internal space 39 Braking rotator 40 Wheel 41 Hub bolt 42 Center hole 43 Through hole 44 Center hole 45 Through holes 46a, 46b Engagement projections 47a, 47b Engagement recesses 48 Cover 49 Bottom plate portion 50 Fitting cylinder portion 51 Vent hole 52 Axial portion 53 Small diameter portion 54 Large diameter portion 55 Stepped portion 56 Fitting hole 57a, 57b Cage

Claims (5)

an outer ring that has a double-row outer ring raceway on its inner peripheral surface and that is supported and fixed to a suspension system and does not rotate;
a hub having a hub-side through-hole axially penetrating a central portion thereof, a double-row inner ring raceway on an outer peripheral surface, and a wheel fixed to rotate together with the wheel;
a plurality of rolling elements arranged to be free to roll between the double-row outer ring raceway and the double-row inner ring raceway;
a seal ring that closes an 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;
a cap that is fitted to the axially inner end of the outer ring and closes the axially inner opening of the outer ring;
a valve device having a pair of elastic members;
with
The pair of elastic members has through holes axially penetrating through positions that are not aligned with each other, and includes flat plate portions whose axial side surfaces are in contact with each other, and radially outer ends of the flat plate portions. inclined plate portions extending in directions away from each other as they go radially outward and fitted inside the inner peripheral surfaces of the hub-side through holes ,
hub unit bearings. the first elastic member of the pair of elastic members further includes a first engaging portion at a position radially deviated from the central axis of the flat plate portion of the first elastic member;
A second elastic member of the pair of elastic members further includes a second engaging portion that engages with the first engaging portion in an uneven manner,
A hub unit bearing according to claim 1. In the valve device, the pair of elastic members having the same shape are arranged symmetrically with respect to an imaginary plane perpendicular to the central axis of the hub, and in phase with respect to the circumferential direction of the through holes of the pair of elastic members. are combined in a staggered state,
A hub unit bearing according to claim 1 or 2. one of the pair of elastic members further comprises a shaft portion protruding from the flat plate portion toward the other elastic member of the pair of elastic members,
the other elastic member further includes a fitting hole into which the shaft portion is fitted;
A hub unit bearing according to claim 1 or 2. further comprising a cover fitted inside a portion of the inner peripheral surface of the hub-side through hole axially outer than the portion provided with the valve device ,
The cover has a bottom plate portion including at least one vent hole that penetrates in the axial direction, and a fitting plate portion that is axially bent from a radially outer end of the bottom plate portion.
A hub unit bearing according to any one of claims 1 to 4.

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