JP2021070345A - Hub unit bearing - Google Patents

Abstract

To provide a structure capable of preventing a rotating body for braking from falling off carelessly even in a state where a hub bolt is removed and reducing a manufacturing cost.SOLUTION: A rotating flange 9 has adsorption means 13 made of rubber magnet on an axially outer side surface. A rotating body 12 for braking is magnetically adsorbed by the adsorption means 13 and supported with respect to the rotating flange 9.SELECTED DRAWING: Figure 2

Description

The present invention relates to hub unit bearings for rotatably supporting the wheels of an automobile with respect to a suspension device.

The wheels of the vehicle and the rotating body for braking are rotatably supported by the hub unit bearings with respect to the suspension system. The hub unit bearing is free to roll between a geostationary wheel having a double row of geostationary orbits, a rotating wheel having a double row of rotating orbits and a rotating flange, and the double row of stationary orbits and the double row of rotating orbits. It is equipped with a double-row rolling element arranged in. The stationary wheel is supported and fixed to a knuckle constituting the suspension device. The wheel and the rotating body for braking are supported with respect to the rotating flange.

In recent years, in order to reduce the size and weight, a hub bolt through which a through hole provided in a wheel constituting a wheel and a rotating body for braking is inserted is screwed into a female screw hole provided in a rotating flange to form the wheel and the wheel and the rotating body for braking. A hub unit bearing that supports a rotating body for braking on the rotating flange has been proposed. In a hub unit bearing that uses a hub bolt, if the hub bolt is removed when the wheel is replaced, the braking rotating body is not supported by the rotating flange, and the braking rotating body is a pilot of the rotating wheel. There is a possibility of falling out of the club.

Further, in the hub unit bearing using the hub bolt, when the wheel and the braking rotating body are fastened together with the rotating flange, the through hole of the wheel and the through hole of the braking rotating body are formed. , It is necessary to match the phases of the rotating flange with the female screw holes in each circumferential direction.

According to Japanese Patent Application Laid-Open No. 2001-180211 (Patent Document 1), a small through hole is formed in a portion of the rotating body for braking that is deviated from the attachment hole for inserting the coupling member in the circumferential direction. Described is a hub unit bearing in which a screw inserted through a small through hole is screwed into a small screw hole formed in a rotating flange.

Like the hub unit bearing described in JP-A-2001-180211, a structure in which the rotating body for braking is supported on the rotating flange by a screw different from the coupling member for supporting the rotating body together with the wheel on the rotating flange. If adopted, in a hub unit bearing using a hub bolt as the coupling member, the braking rotating body will not fall off from the pilot portion of the rotating wheel even if the hub bolt is removed due to wheel replacement.

Further, in a state where the braking rotating body is supported by the screw on the rotating flange, the phases of the through hole of the braking rotating body and the female screw hole of the rotating flange in the circumferential direction are the same. Therefore, when the wheel constituting the wheel and the braking rotating body are fastened together with respect to the rotating flange, the through hole of the wheel and the female screw hole of the rotating flange (and the passing of the braking rotating body) are passed. It is only necessary to match the phase with respect to the circumferential direction with the hole). Therefore, the wheel replacement work can be facilitated.

Japanese Unexamined Patent Publication No. 2001-180211

However, a hub unit in which a hub bolt is used as a coupling member for supporting the wheel and the rotating body for braking on the rotating flange, and the rotating body for braking is supported on the rotating flange by a screw different from the hub bolt. Bearings have room for improvement in terms of reducing manufacturing costs.

The machine screw hole for screwing the screw is formed by tapping the rotating flange. However, if the machine screw hole having a small inner diameter is formed by tapping on the rotating flange having a large wall thickness (thickness in the axial direction), troubles such as breakage of the tool (tap) are likely to occur, and the hub unit bearing It causes an increase in manufacturing cost.

In view of the above circumstances, the present invention can prevent the braking rotating body from being inadvertently dropped even when the hub bolt is removed in the hub unit bearing using the hub bolt, and reduces the manufacturing cost. The purpose is to realize a structure that can be used.

The hub unit bearing of the present invention
A geostationary wheel having a double row of geostationary orbits on the inner or outer peripheral surface,
A rotating wheel having a double-row rotating track and a rotating flange protruding outward in the radial direction on the peripheral surface of the inner peripheral surface and the outer peripheral surface facing the double-row geostationary orbit. ,
A plurality of rolling elements, which are rotatably arranged between the double-row geostationary orbit and the double-row rotary orbit, are provided.
The rotating flange has female screw holes at a plurality of positions in the circumferential direction, and has suction means for sucking and supporting the rotating body for braking on the outer surface in the axial direction.
Regarding the hub unit bearing of the present invention, the outer side in the axial direction means the outer side in the width direction (left side in FIGS. 1 to 3) of the vehicle when assembled to the automobile, and the inner side in the axial direction means the outer side in the axial direction. The center side in the width direction of the vehicle in the found state (right side of FIGS. 1 to 3).

The suction means can be arranged on a portion of the axially outer surface of the rotating flange that is located radially outside the female screw hole.
Alternatively, the suction means is a portion of the axially outer surface of the rotating flange that is located radially inside the female screw hole, or has a radial position that coincides with the female screw hole and is from the female screw hole. It can be placed in a portion deviated in the circumferential direction.

The suction means can be configured by a magnet. Alternatively, the suction means may be configured by a suction cup.

The magnet or the suction cup can be arranged on the outer surface of the rotating flange in the axial direction over the entire circumference. In other words, the magnet or the suction cup can be configured in an annular shape.
Alternatively, the magnet or the suction cup can be arranged at a plurality of locations in the circumferential direction on the axial outer surface of the rotating flange.

The rotating wheel has a pilot portion at an end portion on the outer side in the axial direction.
The pilot portion has a large-diameter fitting surface portion that fits the center hole of the braking rotating body on the inner portion in the axial direction of the outer peripheral surface without rattling (by gap fitting or light press fitting with a minute gap). It is possible to have a small-diameter fitting surface portion for outerly fitting the center hole of the wheel constituting the wheel on the axially outer portion of the outer peripheral surface.

The stationary ring is composed of an outer ring, and the double-row stationary track is composed of a double-row outer ring track provided on the inner peripheral surface of the outer ring.
The rotary wheel can be configured by a hub, and the double-row rotary track can be configured by a double-row inner ring track provided on the outer peripheral surface of the hub.

Alternatively, the stationary wheel is composed of an inner member, and the double-row geostationary track is composed of a double-row inner ring track provided on the outer peripheral surface of the inner member.
The rotating wheel can be formed of an outer member, and the double-row rotating track can be formed of a double-row outer ring track provided on the inner peripheral surface of the outer member.

According to the hub unit bearing of the present invention, it is possible to prevent the braking rotating body from being inadvertently dropped even when the hub bolt is removed, and it is possible to reduce the manufacturing cost.

FIG. 1 is a cross-sectional view showing a first example of an embodiment of the present invention. FIG. 2 is an enlarged view of the upper left portion of FIG. FIG. 3 is a diagram corresponding to FIG. 2 showing a second example of the embodiment of the present invention.

[First Example of Embodiment]
1 and 2 show a first example of an embodiment of the present invention. The hub unit bearing 1 of this example is a hub unit bearing for driven wheels, and includes an outer ring 2 which is a stationary wheel, a hub 3 which is a rotating wheel, and a plurality of rolling elements 4a and 4b.

The outer ring 2 has a double-row outer ring tracks 5a and 5b on the inner peripheral surface, and has a stationary flange 6 protruding outward in the radial direction at the intermediate portion in the axial direction. The stationary flange 6 has support holes 7 penetrating in the axial direction at a plurality of locations in the circumferential direction in the middle portion in the radial direction. The outer ring 2 is supported and fixed to the suspension device by a bolt inserted through the support hole 7 of the stationary flange 6, and does not rotate even when the wheel rotates.

The hub 3 is arranged coaxially with the outer ring 2 inside the outer ring 2 in the radial direction. The hub 3 is provided in the double-row inner ring raceways 8a and 8b provided on the outer peripheral surface and a portion located axially outward from the axially outer end of the outer ring 2, and is provided outward in the radial direction. It has a protruding rotary flange 9 and a cylindrical pilot portion 10 provided at an axially outer end.

The rotary flange 9 has female screw holes 11 at a plurality of circumferential directions in the middle portion in the radial direction, and the suction means 13 for sucking and supporting the rotating body 12 for braking such as a disk or a drum on the outer surface in the axial direction. Has.

In this example, the suction means 13 is composed of a rubber magnet in which magnetic powder is mixed in rubber, and the entire portion of the outer surface of the rotary flange 9 in the axial direction located on the outer side in the radial direction of the female screw hole 11. It is provided over the circumference. That is, a concave groove 14 is provided on the outer surface of the rotary flange 9 in the axial direction, which is located radially outside the female screw hole 11, over the entire circumference, and the annular suction means 13 is arranged inside the concave groove 14. doing. The suction means 13 is adhesively supported on the bottom surface of the concave groove 14 by an adhesive or the like.

The pilot portion 10 is a large-diameter fitting surface portion in which the central hole 15 of the rotating body 12 for braking is externally fitted to the inner portion of the outer peripheral surface in the axial direction without rattling (by gap fitting or light press fitting with a minute gap). A small-diameter fitting surface portion 19 for externally fitting the center hole 18 of the wheel 17 constituting the wheel is provided on the outer peripheral portion of the outer peripheral surface in the axial direction.

The hub 3 of this example includes an inner ring 20 and a hub ring 21.

The inner ring 20 has an inner ring track 8a on the outer peripheral surface, which is the inner side in the axial direction among the double-row inner ring tracks 8a and 8b.

The hub ring 21 has an inner ring raceway 8b on the outer side in the axial direction among the double-row inner ring raceways 8a and 8b at the axially intermediate portion of the outer peripheral surface. Further, the hub wheel 21 has a cylindrical pilot portion 10 at an end portion on the outer side in the axial direction, and is a portion located on the outer side in the axial direction with respect to the inner ring track 8b on the outer side in the axial direction. A rotating flange 9 projecting outward in the radial direction is provided in a portion adjacent to the inner side in the axial direction of the above.

Further, the hub ring 21 has a smaller outer diameter than a portion adjacent to the outer side in the axial direction in a portion located inside the inner ring track 8b on the outer side in the axial direction, and a fitting cylinder portion into which the inner ring 20 is externally fitted. Has 22. Further, the hub ring 21 has a caulking portion 23 that bends radially outward from the axially inner end of the fitting cylinder portion 22 and presses the axially inner end surface of the inner ring 20. That is, the hub 3 has a stepped surface 24 existing at the axially outer end of the fitting cylinder 22 in a state where the inner ring 20 is externally fitted to the fitting cylinder 22 of the hub ring 21, and the caulking portion 23. The inner ring 20 is sandwiched between the inner rings 20 from both sides in the axial direction, and the inner ring 20 and the hub ring 21 are coupled and fixed. However, the hub can also be configured by connecting and fixing the inner ring and the hub ring with nuts.

A plurality of rolling elements 4a and 4b are rotatably arranged between the double-row outer ring tracks 5a and 5b and the double-row inner ring tracks 8a and 8b, respectively, while being held by the cages 25a and 25b. Has been done. As a result, the hub 3 is rotatably supported inward in the radial direction of the outer ring 2.

In this example, balls are used as the rolling elements 4a and 4b, but tapered rollers may be used instead of the balls. Further, in this example, the pitch circle diameter of the rolling element 4a in the inner row in the axial direction and the pitch circle diameter of the rolling element 4b in the outer row in the axial direction are the same as each other. It can also be applied to PCD type hub unit bearings having different diameters in which the pitch circle diameter of the moving body and the pitch circle diameter of the rolling elements in the outer row in the axial direction are different from each other.

The braking rotating body 12 and the wheel 17 are coupled and fixed to the rotating flange 9 of the hub 3 by the hub bolt 26. That is, the center hole 15 of the braking rotating body 12 is fitted onto the large-diameter fitting surface portion 16 of the pilot portion 10 without rattling, and the center hole 18 of the wheel 17 is fitted into the small-diameter fitting surface portion of the pilot portion 10. The hub bolts 26 through which the through holes 27a and 27b provided at a plurality of radial intermediate portions of the rotating body 12 for braking and the wheel 17 are inserted into the female screw holes 11 of the rotating flange 9 in the state of being fitted outward to the 19 Is screwed into. As a result, the braking rotating body 12 and the wheel 17 are coupled and fixed to the rotating flange 9 of the hub 3.

In the hub unit bearing 1 of this example, the rotary flange 9 is provided with the suction means 13 made of a rubber magnet on the outer surface in the axial direction. Further, the braking rotating body 12 such as a disc or a drum is made of a magnetic metal material. Therefore, the central hole 15 of the braking rotating body 12 is fitted onto the large-diameter fitting surface portion 16 of the pilot portion 10 without rattling, and the axial inner side surface of the braking rotating body 12 is the shaft of the rotating flange 9. The braking rotating body 12 is magnetically attracted by the attracting means 13 and supported by the rotating flange 9 in a state of being in contact with the outer surface in the direction. Therefore, even in the state where the hub bolt 26 is removed (the state before the rotating flange 9 and the braking rotating body 12 and the wheel 17 are jointly tightened by the hub bolt 26), the braking rotating body 12 is still the pilot portion 10 of the hub 3. It is possible to prevent the vehicle from accidentally falling off. Further, the rotating flange 9 and the braking rotating body 12 can be temporarily fixed in a state where the female screw holes 11 and the through holes 27a are in phase with each other in the circumferential direction. This makes it possible to facilitate the work of jointly tightening the rotating flange 9, the braking rotating body 12 and the wheel 17 with the hub bolt 26.

In this example, by providing the suction means 13 made of a rubber magnet on the axially outer surface of the rotary flange 9, the braking rotating body 12 carelessly moves from the pilot portion 10 of the hub 3 even when the hub bolt 26 is removed. It prevents it from falling off. Therefore, according to the hub unit bearing 1 of this example, a machine screw hole having a small inner diameter is formed by tapping on a rotary flange having a large wall thickness like the hub unit bearing described in Japanese Patent Application Laid-Open No. 2001-180211. do not have to. Therefore, it is possible to prevent troubles such as breakage of the tool (tap) used for tapping, and it is possible to suppress the manufacturing cost of the hub unit bearing 1.

In the hub unit bearing 1 of this example, the braking rotating body 12 has the central hole 15 outside the outer peripheral surface of the pilot portion 10 without rattling on the large-diameter fitting surface portion 16 provided on the inner portion in the axial direction. It fits. Therefore, if the braking rotating body 12 is attracted by the suction means 13 with a force that does not tilt with respect to the rotating flange 9, the braking rotating body 12 is acted on by the moment load applied to the braking rotating body 12 based on gravity. It is possible to prevent the 12 from further tilting, and it is possible to prevent the braking rotating body 12 from falling off from the pilot portion 10.

From the viewpoint of suppressing the inclination of the braking rotating body 12 with respect to the rotating flange 9, it is desirable that the braking rotating body 12 is attracted by the suction means 13 on the outer side in the radial direction as much as possible. In this regard, in this example, since the suction means 13 is provided on the outer surface in the axial direction of the rotary flange 9 in the radial direction from the female screw hole 11, the rotating body 12 for braking is provided on the rotary flange 9. It can effectively prevent tilting. However, in the case of carrying out the present invention, the suction means is used as the axially inner portion of the rotary flange on the outer surface in the radial direction, or the portion whose radial position coincides with the female screw hole (circumferential direction). It can also be provided in the portion between the female screw holes adjacent to each other.

Further, in this example, the suction means 13 is provided on the outer surface of the rotary flange 9 in the axial direction in an annular shape over the entire circumference, but when the present invention is carried out, the suction rotating body is attracted and falls off. As long as this can be prevented, the shape and number of the suction means are not particularly limited. For example, suction means can be provided at a plurality of locations in the circumferential direction on the outer surface of the rotating flange in the axial direction. In this case, recesses are provided at a plurality of locations in the circumferential direction on the outer surface of the rotary flange in the axial direction, and the suction means are arranged inside the recesses.

In this example, the suction means 13 is composed of a rubber magnet in which magnetic powder is mixed in rubber. However, in the case of carrying out the present invention, if the rotating body for braking can be sucked, the material constituting the suction means. And the structure are not particularly limited. For example, the adsorption means may be composed of a permanent magnet other than a rubber magnet, such as a plastic magnet or a ferrite magnet in which magnetic powder is hardened with a thermoplastic synthetic resin, or may be composed of a sucker.

In this example, a case where the present invention is applied to a hub unit bearing 1 for a driven wheel in which the hub 3 is solid (not provided with an engaging hole penetrating in the axial direction) has been described, but the hub of the present invention has been described. Unit bearings can also be applied to hub unit bearings for drive wheels where the hub has engaging holes for engaging the drive shaft.

In this example, the case where the present invention is applied to the so-called third generation hub unit bearing 1 in which the inner ring raceway 8b on the outer side in the axial direction is directly formed on the outer peripheral surface of the intermediate portion in the axial direction of the hub wheel 21 has been described. The invention can be applied to hub unit bearings other than the third generation hub unit bearings. For example, the present invention can be applied to a so-called 2.5th generation hub unit bearing in which a shaft member is provided with a hub formed by externally fitting a pair of inner rings having inner ring tracks on the outer peripheral surfaces thereof.

Further, in the hub unit bearing 1 of this example, the outer ring 2 constitutes a stationary wheel supported and fixed to the suspension device, and the hub 3 constitutes a rotating wheel for supporting the braking rotating body and the wheel, so-called. It has an inner ring rotation type structure. However, the present invention is a so-called outer ring rotation type in which the outer member constitutes a rotating body for braking and a rotating wheel that supports the wheel, and the inner member constitutes a stationary wheel that is supported and fixed to the suspension device. It can also be applied to hub unit bearings. In this case, for example, the inner member can be composed of a pair of inner rings each having an inner ring orbit which is a geostationary orbit on the outer peripheral surface.

[Second Example of Embodiment]
FIG. 3 shows a second example of the embodiment of the present invention. In the hub unit bearing 1a of this example, the rotating flange 9a has suction means 13a for sucking and supporting the braking rotating body 12 at a plurality of positions in the circumferential direction. In this example, the suction means 13a is composed of a suction cup made of a flexible material such as rubber or synthetic resin.

The rotary flange 9a has a thin portion 28 having a wall thickness (axial thickness) smaller than that of the radial inner portion at the radial outer portion of the female screw hole 11. Further, the rotary flange 9a has recesses 29 at a plurality of circumferential directions on the outer surface of the thin portion 28 in the axial direction, and the bottom surface of the recess 29 (the surface facing outward in the axial direction) and the axial direction of the thin portion 28. It has a small through hole 30 that communicates with the inner surface.

The suction means 13a has a dish-shaped portion 31, a protrusion 32 protruding from the axial inner side surface of the dish-shaped portion 31, and a protrusion 32 protruding radially outward from the tip portion of the protrusion 32, and from the inner diameter of the small through hole 30. Also includes a stopper 33 having a large outer diameter. In order to support the suction means 13a on the rotary flange 9a, the stopper 33 and the protrusion 32 are inserted into the small through hole 30 from the outside in the axial direction with the stopper 33 elastically reduced in diameter, and the dish-shaped portion is formed. 31 is arranged inside the recess 29. After that, the stopper 33 is elastically restored to prevent the protrusion 32 from falling out of the small through hole 30, thereby supporting the suction means 13a on the rotary flange 9a.

In this example, when the dish-shaped portion 31 of the suction means 13a is elastically deformed as the axial inner surface of the braking rotating body 12 is pressed against the axial outer surface of the rotating flange 9a, the inner surface of the dish-shaped portion 31 is formed. The air between the rotating body 12 for braking and the inner surface in the axial direction is released, and the pressure drops. As a result, the braking rotating body 12 is attracted by the suction means 13a and supported by the rotating flange 9a.

When removing the braking rotating body 12 from the hub 3a, the stopper 33 is pressed outward in the axial direction. As a result, the dish-shaped portion 31 is elastically deformed so as to be crushed, air is introduced between the inner surface of the dish-shaped portion 31 and the axial inner surface of the braking rotating body 12, and the suction force by the suction means 13a is lost. Let me.

As described above, in the hub unit bearing 1a of this example, when the braking rotating body 12 is removed from the hub 3a, the suction force by the suction means 13a can be easily lost, and the braking rotating body 12 is removed. Can be done easily (with a small force).

In this example, the suction means 13a is provided on the outer surface of the rotary flange 9 in the axial direction with respect to the female screw hole 11 in the radial direction. However, even when a suction cup is used as the suction means, the suction means is used on the axially inner surface of the rotating flange, which is the inner portion in the radial direction from the female screw hole, or the portion whose radial position coincides with the female screw hole ( It can also be provided in the portion between the female screw holes adjacent to each other in the circumferential direction). The composition and action of other parts are the same as those of the first example of the embodiment.

1, 1a Hub unit bearing 2 Outer ring 3, 3a Hub 4a, 4b Rolling body 5a, 5b Outer ring track 6 Static flange 7 Support hole 8a, 8b Inner ring track 9, 9a Rotating flange 10 Pilot part 11 Female screw hole 12 Braking rotating body 13 , 13a Suction means 14 Concave groove 15 Center hole 16 Large diameter fitting surface 17 Wheel 18 Center hole 19 Small diameter fitting surface 20 Inner ring 21 Hub wheel 22 Fitting cylinder 23 Crimping part 24 Step surface 25a, 25b Cage 26 Hub bolt 27a , 27b through hole 28 thin wall part 29 recess 30 small through hole 31 dish-shaped part 32 protrusion 33 stopper

Claims (3)

A geostationary wheel having a double row of geostationary orbits on the inner or outer peripheral surface,
A rotating wheel having a double-row rotating track and a rotating flange protruding outward in the radial direction on the peripheral surface of the inner peripheral surface and the outer peripheral surface facing the double-row geostationary orbit. ,
A plurality of rolling elements rotatably arranged between the double-row geostationary orbit and the double-row rotary orbit are provided.
The rotary flange has female screw holes at a plurality of positions in the circumferential direction, and has suction means for sucking and supporting the rotating body for braking on the outer surface in the axial direction.
Hub unit bearing. The suction means is arranged on a portion of the axially outer surface of the rotating flange that is located radially outside the female screw hole.
The hub unit bearing according to claim 1. The suction means is composed of a magnet.
The hub unit bearing according to claim 1 or 2.

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