JP2007271044A - Rolling bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double row tapered roller bearing device with a coupler ring to be used for transmitting or cutting off vehicle driving force to or from a hub shaft, having high bearing rigidity. <P>SOLUTION: The bearing device comprises the hub shaft 1 having a flange portion 1a to be connected to the wheel of an automobile, a double row tapered roller bearing 2 externally fitted and mounted onto the hub shaft 1 and having an outer ring 2c and inner rings 2a, 2b for guiding a tapered roller 21a, and the coupler ring 3 to be used for transmitting or cutting off the vehicle driving force to or from the hub shaft 1. The coupler ring 3 is threaded and mounted onto the outer peripheral face of the hub shaft 1 to impart thrust to the bearing 2 in the axial direction toward the flange portion 1a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rolling bearing device for a wheel used for rotatably supporting a wheel on a suspension device such as an automobile.

  Some wheel rolling bearing devices for part-time 4WD vehicles capable of switching between 2WD (2-wheel drive) mode and 4WD (4-wheel drive) mode are capable of switching driving force intermittently.

  Specifically, as a switching mechanism that interrupts the driving force of the vehicle with respect to the hub shaft to which the wheel is mounted, it is fitted on the end of the hub shaft on the vehicle inner side (the side opposite to the side where the wheel is mounted). One having a coupler ring having a spline groove on the outer peripheral surface is known.

  This wheel rolling bearing device is provided on the outer peripheral surface of an adjacent joint outer ring (constant velocity universal joint outer ring), and can slide in the axial direction on the spline groove having the same diameter as the coupler ring and on both adjacent spline grooves. And a gear support that is connected to a wheel support device via a coupler ring.

  In this case, when the gear ring is moved to a position where it engages with both of the spline grooves, the hub shaft and the joint outer ring are operatively connected, and the driving force of the vehicle is transmitted to the hub shaft via the gear ring. . Further, when the gear ring is moved to a position that engages only with the spline groove of the joint outer ring, transmission of the driving force to the hub shaft can be disconnected.

  In this wheel rolling bearing device, as a method of fixing the coupler ring to the hub shaft, a method of caulking the coupler ring by caulking the shaft end of the hub shaft and bending outward in the radial direction (generally referred to as shaft end caulking). (See Patent Document 1).

When such a rolling bearing device for a wheel is used, the two wheels that are driven wheels in the 2WD mode do not rotate the drive system (such as an axle shaft, a differential, a propeller shaft, etc.). It is possible to improve the durability of the drive parts and the like.
JP 2000-351336 A

  As described above, according to the bearing device described in Patent Document 1, the double-row tapered roller bearing and the coupler ring are pressed against the hub shaft by pressing the coupler ring and the double-row tapered roller bearing adjacent thereto with the shaft end caulking. As well as preloading the double row tapered roller bearing and coupler ring.

  However, in the case of such a shaft end caulking, the caulking pressure when deforming the shaft end of the hub shaft is dispersed radially outward of the hub shaft, and the coupler is interposed between the caulking portion and the double row tapered roller bearing. Since the ring is interposed, the preload management for applying the preload to the double row tapered roller bearing at the time of mass production becomes complicated and takes time. In addition, the rolling bearing device for wheels has been trying to improve the rigidity for the purpose of improving the steering feeling during traveling, but recently, it has been demanded to improve the rigidity. .

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a preload in a rolling bearing device for a wheel having a coupler ring used for transmission and disconnection of a driving force of a vehicle to a hub shaft. An object of the present invention is to provide a rolling bearing device for a wheel that can be easily managed and has a higher bearing rigidity.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a flange portion for attaching a wheel is provided on one end side in the axial direction, and a shaft of the hub shaft is in contact with the flange portion. A rolling bearing comprising an inner ring externally fitted to the outer peripheral surface of the central portion in the direction, an outer ring attached to a vehicle suspension, and a rolling element interposed between the outer ring and the inner ring, and the inner ring Is attached to the outer peripheral surface of the hub shaft in contact with the end surface on the other end side in the axial direction, and when the vehicle driving force is transmitted to the hub shaft, it is operatively connected to a joint outer ring, and the vehicle driving force is In a wheel rolling bearing device having a coupler ring that is separated from a joint outer ring when not transmitted to the hub shaft, the coupler ring is screwed to the outer peripheral surface of the hub shaft and the inner ring is moved forward. By pressing the axial direction towards the flange, it has to impart a preload to the rolling bearing, and the gist.

  According to the first aspect of the present invention, it is possible to apply the preload by pressing the rolling bearing against the flange portion by tightening the coupler ring with respect to the hub shaft. As a result, the preload can be evenly applied to the rolling bearing without being dispersed in the radial direction, and the preload management of the rolling bearing can be easily and reliably performed in order to increase the bearing rigidity. Furthermore, the steps and equipment required for the caulking operation can be omitted, and the assembly cost of the wheel rolling bearing device can be reduced.

  According to a second aspect of the present invention, in the rolling bearing device for a wheel according to the first aspect, the coupler ring is fastened and fixed to the hub shaft along with the rotation of the joint outer ring when the vehicle moves forward. The gist of this is that it is screwed in the direction.

  According to the configuration of the second aspect, when the vehicle moves forward, the coupler ring of the wheel rolling bearing device disposed on the left side of the vehicle, such that the coupler ring is fastened to the hub shaft by the rotation of the joint outer ring, and A threaded portion is formed on the hub shaft in the direction of the right-hand thread. On the other hand, in the wheel rolling bearing device disposed on the right side of the vehicle, a thread portion is formed in the direction of the left-hand thread. As a result, when the vehicle moves forward, the coupler ring is screwed into the hub shaft, and loosening of the coupler ring can be effectively prevented.

  According to a third aspect of the present invention, there is provided the wheel rolling bearing device according to the first or second aspect, wherein a part or all of the end portion of the hub shaft in the circumferential direction protrudes radially outward. The gist is that the ring is brought into contact with the end face on the other axial end side of the ring.

  According to the third aspect of the present invention, the coupler ring can be prevented from loosening by the protruding portion protruding from a part or all of the end portion of the hub shaft in the circumferential direction, and the coupler ring can be screwed into the hub shaft more stably. It becomes fixed. As a result, the high bearing rigidity provided in the wheel rolling bearing device can be continuously maintained.

  According to the present invention, there is provided a rolling bearing device for a wheel having a coupler ring used for transmission and disconnection of a driving force of a vehicle to a hub shaft, and can easily manage preload and ensure higher bearing rigidity. Will be able to.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
As shown in FIG. 1, a disc-shaped or cross-shaped flange portion 1a is formed on the outer peripheral surface of one axial end portion (vehicle outer side) (left side in FIG. 1) of the hub shaft 1 so as to extend radially outward. Is provided. A wheel (not shown) of the wheel is fastened to the flange portion 1a via a bolt b. Further, a male screw portion 11a into which a coupler ring 3 to be described later is screwed is formed on the outer peripheral surface of the end portion 1e of the other axial end portion (vehicle inner side) (right side in FIG. 1) of the hub shaft 1. Since the hub shaft 1 is disposed on the left side of a vehicle such as an automobile, the male thread portion 11a is oriented in the right-hand screw direction so that the coupler ring 3 is tightened onto the hub shaft 1 as the vehicle moves forward. Is formed. Here, an internal thread portion 3a is formed on the inner peripheral surface of the coupler ring 3 in the right-handed screw direction.

A double-row tapered roller bearing 2 for rotatably supporting the hub shaft 1 with respect to the suspension device of the vehicle body is fitted on the outer peripheral surface of the central portion in the axial direction of the hub shaft 1.
The inner ring of the double-row tapered roller bearing 2 includes a first inner ring member 2a and a second inner ring member 2b disposed in this order at one end and the other end in the axial direction. An end surface 22a on one axial end side of the first inner ring member 2a is in surface contact with an end surface 1b on the other axial end side of the flange portion 1a of the hub shaft 1. The second inner ring member 2b is disposed adjacent to the other axial end of the first inner ring member 2a. The first inner ring member 2a has a first inner ring raceway 201a that is a raceway surface of the first row of tapered rollers 21a, and the second inner ring member 2b is a raceway surface of the second row of tapered rollers 21b. Two inner ring raceways 201b are provided.

  On the other hand, the outer ring 2c of the double-row tapered roller bearing 2 has a first outer ring raceway 202a facing the first inner ring raceway 201a and a second outer ring raceway 202b facing the second inner ring raceway 201b. A flange portion 2d is provided on the outer peripheral surface of the outer ring 2c so as to extend radially outward. The flange portion 2d is formed with a bolt hole 2f used for attachment to a vehicle suspension system (not shown).

  A ball bearing 5 and a needle roller bearing 7 are interposed between the hub shaft 1 and an axle 4a provided on the inner end face of a joint outer ring 4 as an outer ring of a constant velocity universal joint. Is rotatably supported with respect to the axle 4a. The ball bearing 5 is a deep groove ball bearing and is disposed so that the axial movement is restricted by the retaining ring 6 at substantially the same axial position as the flange portion 1 a of the hub shaft 1. Further, the needle roller bearing 7 is disposed on the other axial end side than the ball bearing 5, and the axial position thereof is the second inner ring member of the double row tapered roller bearing 2 provided on the outer peripheral surface of the hub shaft 1. It is almost the same as 2b. By providing these two bearings 5 and 7, the hub shaft 1 and the axle 4a are firmly supported in a coaxial state. In addition, by using the needle roller bearing 7 as the bearing on the other axial end side, it is easy to ensure the thickness of the hub shaft 1 in the portion where the bearing 7 is attached.

  On the other end side in the axial direction of the second inner ring member 2b of the double-row tapered roller bearing 2 described above, a coupler ring 3 which is a ring-shaped member is provided. The coupler ring 3 is provided in contact with the end surface 2e on the other axial end side of the second inner ring member 2b. A spline groove 3b is formed on the outer peripheral surface of the coupler ring 3, and the female screw portion 3a is formed on the inner peripheral surface of the coupler ring 3 in the right-handed screw direction as described above. Moreover, the external thread part 11a is formed in the outer peripheral surface of the edge part 1e of the axial direction other end side of the hub shaft 1 as mentioned above. The coupler ring 3 is screwed to the male screw portion 11a of the hub shaft 1 so as to press the second inner ring member 2b in the axial direction toward the end surface 1b on the vehicle inner side of the flange portion 1a. Specifically, the coupler ring 3 causes the second inner ring member 2b to be connected to the end surface of the flange portion 1a via the first inner ring member 2a adjacent to the second inner ring member 2b by the tightening force of the female thread portion 3a to the hub shaft 1. Strongly pressed toward 1b. Thus, the fastening force acting from the coupler ring 3 secures the coupler ring 3 and the first and second inner ring members 2a and 2b to the hub shaft 1.

  On the outer peripheral surface of the joint outer ring 4 in the vicinity of the coupler ring 3, a joint outer ring side spline groove 4b having the same diameter and the same shape as the outer peripheral spline groove 3b of the coupler ring 3 is disposed. The outer peripheral spline groove 3b and the joint outer ring side spline groove 4b are coaxial with each other. The spline groove 8b on the inner peripheral surface of the ring-shaped gear ring 8 slidable in the axial direction is engaged with both the outer peripheral spline groove 3b and the joint outer ring side spline groove 4b (state shown in FIG. 1). The rotational driving force of the axle 4a is transmitted to the hub shaft 1. On the other hand, when the gear ring 8 moves to the other axial end side (the right side in FIG. 1), the gear ring 8 meshes with the joint outer ring side spline groove 4b, but meshes with the outer peripheral spline groove 3b of the coupler ring 3. Thus, the rotational driving force of the axle 4a is not transmitted to the hub shaft 1. As described above, the gear ring 8 is slid back and forth in the axial direction, thereby enabling switching of the driving force of the axle 4a to the hub shaft 1 to be intermittent. Although not specifically shown, the gear ring 8 is slid by a sliding mechanism using appropriate power means such as air or hydraulic pressure.

(Assembly method of bearing device)
Next, a method for assembling the double-row tapered roller bearing device of this embodiment, particularly a procedure for screwing and mounting the coupler ring 3 to the hub shaft 1 will be described. The external diameter of the external thread of the external thread portion 11a at the cylindrical end 1e on the other axial end side to which the coupler ring 3 is screwed is substantially the same as the internal diameter of the internal thread of the internal thread portion 3a of the coupler ring 3. . In this state, the end 1e of the hub shaft 1 has a shape that allows mounting of the first inner ring member 2a, the second inner ring member 2b, and the like. Further, the end portion 1e of the hub shaft 1 is in a state of slightly projecting toward the vehicle inner side from the end surface 3c of the coupler ring 3 in a state where the coupler ring 3 is screwed in until the coupler ring 3 contacts the second inner ring member 2b. .

  The double row tapered roller bearing 2 is externally fitted toward the flange portion 1a from the end portion 1e side of the hub shaft 1 in this state. Next, the coupler ring 3 is externally fitted to the end 1 e of the hub shaft 1 while the internal thread portion 3 a on the inner periphery of the coupler ring 3 is screwed to the external thread portion 11 a on the outer periphery of the hub shaft 1.

(Relationship between vehicle driving behavior and coupler ring mounting condition)
In this embodiment, the coupler ring 3 is screwed and attached in a direction to be tightened with respect to the hub shaft 1 as the joint outer ring 4 (axle 4a) rotates when a vehicle such as an automobile moves forward. That is, on the coupler ring 3 and the hub shaft 1 of the wheel rolling bearing device disposed on the left side of the vehicle, a female screw portion 3a and a male screw portion 11a are formed in the direction of the right screw, respectively. On the other hand, in the rolling bearing device for a wheel arranged on the right side of the vehicle, a female screw portion 3a and a male screw portion 11a are formed in the direction of the left screw, respectively. As a result, when the vehicle moves forward, the coupler ring 3 does not rotate in the loosening direction with respect to the hub shaft 1, and the effect of preventing the coupler ring 3 from being loosened or coming off can be obtained. In the case of a vehicle such as an automobile, it is generally considered that the frequency of forward movement is overwhelmingly higher than the frequency of backward movement, so that the effect of preventing the coupler ring 3 from loosening is obtained from this point as well.

As described above, according to the double row tapered roller bearing device of the present embodiment, the following operations and effects can be obtained.
(1) In this embodiment, the second inner ring member 2b of the double-row tapered roller bearing 2 is connected to the coupler ring 3 by tightening (fastening) the female thread portions 3a and 11a of the end portion 1e of the coupler ring 3 and the hub shaft 1. Is fixed to the hub shaft 1 so as to be pressed in the axial direction toward the flange portion 1a. Thereby, a preload is appropriately applied to the double row tapered roller bearing 2. More specifically, the first and second inner ring members 2b, 2b having a double-row outward structure are mutually connected by the pressing force to the second inner ring member 2b and the reaction force from the end surface 1b of the flange portion 1a. It can be tightened from the back. Then, the tapered rollers 21a and 21b are pressed from the first and second outer ring raceways 202a and 202b by the cylindrical and rigid outer ring 2c to be elastically deformed, so that the effective gap is in an appropriate state. In the present embodiment, as shown in FIG. 1, the second inner ring member 2b and the coupler ring 3 are in surface contact with each other at the end face 2e and the end face 3e. For this reason, the pressing force to the second inner ring member 2b due to the fastening of the coupler ring 3 to the hub shaft 1 is applied more evenly in the axial direction. As described above, the preload for setting the negative internal clearance can be easily and reliably applied to the double row tapered roller bearing 2. As a result, it is possible to provide a double-row tapered roller bearing device in which high bearing rigidity and measures for preventing vibration and noise are ensured.

  (2) In the present embodiment, a preload is applied to the double-row tapered roller bearing 2 by tightening the female thread portions 3a and 11a of the end portion 1e of the coupler ring 3 and the hub shaft 1. In the caulking operation, the coupler ring 3 is pushed outward in the radial direction by the radial component force caused by the caulking at the shaft end, so that the coupler ring 3 is easily distorted in the radial direction. However, in this embodiment, since the fastening of the coupler ring 3 is used instead of the shaft end caulking, such distortion is effectively suppressed. As a result, no gap is generated at the meshing portions of the spline grooves 3b and 8b of the coupler ring 3 and the gear ring 8, and the coupler ring 3 and the joint outer ring 4 are firmly and operatively connected. As a result, the driving force of the vehicle is efficiently transmitted to the wheels via the wheel rolling bearing device.

  (3) The operation of caulking and fixing the coupler ring 3 to the double row tapered roller bearing 2 can be eliminated from the assembly process of the wheel rolling bearing device. As a result, the steps and equipment required for the shaft end caulking can be omitted, and the assembly cost of the double-row tapered roller bearing device can be reduced.

  (4) Since the bearing 2 of this embodiment is provided with the form of a double-row outward tapered roller bearing, it can receive a large circumferential and axial load with a small size. For this reason, it is effective for reducing the size and weight of the double-row tapered roller bearing device, and particularly when used as a drive wheel, the effect of improving the fuel efficiency is great.

The above embodiment may be modified as follows.
In the above embodiment, the coupler ring 3 is mounted without providing the hub shaft 1 with any static structure for preventing the coupler ring 3 from coming off. However, as shown in FIGS. 2 (a) and 2 (b), the end surface 1c on the other axial end side of the hub shaft 1 is spaced at equal angular intervals in the circumferential direction (at intervals of about 120 degrees in FIG. 2 (b)). A projecting portion 1d for preventing the coupler ring 3 from coming off can be formed. In FIG. 2, each projecting portion 1d is formed by projecting the male threaded portion 11a of the hub shaft 1 projecting outward from the end face 3c of the coupler ring 3 outwardly in the radial direction by striking with a suitable jig such as a hammer. It is a thing. These protrusions 1d,... Effectively prevent loosening of the coupler ring 3 when the vehicle moves backward. Here, as shown in FIGS. 2 (a) and 2 (b), each projecting portion 1d is applied to a small-diameter region of the end surface 3c of the coupler ring 3 so that the coupler ring 3 is prevented from loosening more effectively. It is preferable to contact. Accordingly, it is possible to effectively prevent the coupler ring 3 from loosening from the end 1e of the hub shaft 1 and changing the preload on the double-row tapered roller bearing 2 particularly when the vehicle moves backward. FIG. 2B shows an example in which three protrusions 1d are formed at equiangular intervals. However, as long as it is possible to effectively prevent the coupler ring 3 from being loosened or dropped off, two or four protrusions 1d are equal. It may be formed at angular intervals, or five or more may be formed at equiangular intervals. Furthermore, if the loosening of the coupler ring 3 can be effectively prevented, it is not always necessary to arrange the protrusions 1d at equal angular intervals.

  In the above embodiment, the bearing 2 is a double-row tapered roller bearing provided with two first and second inner ring members 2a and 2b disposed in this order at one end and the other end in the axial direction. However, the present invention is not limited to this, and the technical idea of the present embodiment is similarly applied to a structure in which the first inner ring member 2a at one axial end is integrated with the hub shaft 1, as shown in FIG. it can. By integrating the first inner ring member 2a and the hub shaft 1 in this manner, the thickness of the hub shaft 1 is sufficiently secured, the rigidity of the hub shaft 1 against twisting and bending is improved, and the strength of the hub shaft 1 is increased. Improvement is achieved more effectively. Further, since the inner ring member separate from the hub shaft 1 is only the second inner ring member 2b at the other axial end, the coupler ring 3 can more efficiently apply the pressing force to the second inner ring member 2b. Thereby, the bearing rigidity of the double row tapered roller bearing device can be further improved as a whole.

  In the above embodiment, the rolling bearing is a double-row tapered roller bearing using tapered rollers 21a and 21b as rolling elements, but is not limited to this, for example, a double-row outward angular ball using balls as rolling elements. It may be a bearing. In this case, the rolling element comes into rolling contact with the raceway surface, the friction torque is reduced, and further reduction in torque and speed of the wheel rolling bearing device are realized.

  In the above embodiment, the coupler ring is configured such that the second inner ring member 2b is pressed in the axial direction toward the flange portion 1a without interposing any member between the coupler ring 3 and the second inner ring member 2b. 3 was attached. However, for example, a plain washer can be mounted between the coupler ring 3 and the second inner ring member 2b. In this case, the coefficient of friction at the seating surface contact portion increases, and more appropriate torque can be applied when the coupler ring 3 is tightened. Further, in this case, a plain washer having a large outer diameter is selected even when the outer diameter of the coupler ring 3 is small and it is difficult to apply sufficient pressing force to the double row tapered roller bearing 2 by tightening the coupler ring 3. By doing so, a sufficient pressing force can be applied. Further, technical ideas that can be grasped from the above-described embodiments and modifications will be described below.

  In the rolling bearing device for a wheel according to any one of claims 1 to 3, the inner ring includes a ring-shaped inner ring member arranged in a double row at one end and another end in the axial direction. A wheel rolling bearing device in which an inner ring member located at one end in the axial direction is integrated with the hub shaft. In such a configuration, since the inner ring member separate from the hub shaft is only one located on the other end side in the axial direction, the preload can be more efficiently applied to the rolling bearing through the coupler ring. Thereby, the bearing rigidity of the rolling bearing device for wheels is further enhanced.

  4. The rolling bearing device for a wheel according to any one of claims 1 to 3, wherein a plain washer through which a hub shaft passes is interposed between the coupler ring and an inner ring. . When configured in this manner, the friction coefficient at the seating surface contact portion between the flat washer and the other member is increased, and a more appropriate torque is applied when the coupler ring is tightened. Further, even when the outer diameter of the coupler ring is small and sufficient pressing force cannot be applied to the inner ring, such a problem can be corrected by selecting a flat washer having a large outer diameter.

The sectional view of the direction of an axis showing the structure of the double row tapered roller bearing device concerning the embodiment of the present invention. It is a figure which shows the structure of the axial direction other end part of the double row tapered roller bearing apparatus which concerns on embodiment of this invention, (a) is sectional drawing of an axial direction, (b) is from the AA direction in (a). End view (the internal structure is omitted). Sectional drawing which shows the structure of the double row tapered roller bearing apparatus which concerns on the modification of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Hub shaft, 1a ... Flange part, 1e ... End of hub shaft, 2 ... Double row tapered roller bearing, 2a ... 1st inner ring member, 2b ... 2nd inner ring member, 2c ... Outer ring, 3 ... Coupler ring, 3a ... Female thread part, 11a ... Male thread part, 4 ... Joint outer ring

Claims (3)

A hub shaft provided with a flange portion on one end side in the axial direction for attaching a wheel;
An inner ring that abuts on the flange portion and is externally fitted on the outer peripheral surface of the central portion in the axial direction of the hub shaft, an outer ring that is attached to a vehicle suspension, and is interposed between the outer ring and the inner ring. A rolling bearing provided with rolling elements;
When the inner ring is in contact with the end face on the other axial end side of the inner ring and is mounted on the outer peripheral surface of the hub shaft, and transmits the driving force of the vehicle to the hub shaft, the driving force of the vehicle A coupler ring that is disconnected from the outer ring of the joint when not transmitting to the hub shaft,
In the rolling bearing device for wheels provided with
For the wheel, wherein the coupler ring is screwed and attached to the outer peripheral surface of the hub shaft, and the inner ring is pressed in the axial direction toward the flange portion, so that a preload is applied to the rolling bearing. Rolling bearing device. In the rolling bearing device for wheels according to claim 1,
The rolling bearing device for a wheel according to claim 1, wherein the coupler ring is screwed in a direction in which the coupler ring is fastened and fixed to the hub shaft as the joint outer ring rotates when the vehicle moves forward. In the rolling bearing device for wheels according to claim 1 or 2,
A rolling bearing device for a wheel, wherein a part or all of the end portion of the hub shaft in the circumferential direction protrudes radially outward and abuts against an end surface on the other axial end side of the coupler ring.

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