JP5828274B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing.

  Rolling bearings used for vehicle wheels are used in adverse environments that are affected by rainwater and muddy water. Therefore, the outside and inside of the bearings are sealed with a sealing device that is made of elastic material and has excellent durability for muddy water. , Has improved sealing.

  In rolling bearings for wheels, the rotational speed of the rolling bearings suddenly increases in the initial operation of the vehicle, and the temperature of the rolling bearings rises. As a result, the pressure inside the rolling bearings rises, and the grease sealed inside the rolling bearings It may be pushed out from inside and leak. Also, at that time, when the lip of the sealing device is deformed toward the outside of the rolling bearing and the gap between the lip and the sliding contact surface is widened, water or dust enters the inside of the rolling bearing from the outside. There is.

  Further, even when the rolling bearing is operated in a steady state, the rolling bearing is exposed to water or muddy water when the vehicle travels in a puddle or the like and the wheels wind up water or muddy water. In this case, since the rolling bearing whose temperature is rising is rapidly cooled, the pressure inside the rolling bearing is reduced, and water and dust are sucked into the rolling bearing from between the lip and the sliding contact surface. There is a case. Further, the tip of the lip is strongly pressed against the sliding contact surface, the frictional resistance is increased, and the tip of the lip may be significantly worn. If the tip of the lip is worn in this way, the sealing performance of the rolling bearing may be lowered.

  For this reason, the sealing device exposed both inside and outside the bearing is elastically deformed by the pressure difference between the inside and outside of the bearing, so that the volume inside the bearing changes, and the pressure inside the bearing changes to the pressure outside the bearing. There are wheel rolling bearings that are adjusted to approach. (Patent Document 1)

JP 2005-226826 A

  However, in the above rolling bearing, in the assembly process of the bearing, the inner ring, the outer ring, and the rolling element are assembled, then grease is sealed, and finally the sealing device is press-fitted. As the volume of the bearing decreases, the pressure inside the bearing increases. The pressure increase inside the bearing when the sealing device is press-fitted is much larger than the pressure increase due to the temperature change described above, and the pressure increase when the rolling bearing press-fits the sealing device is adjusted by the internal pressure adjusting means. There are times when I can't. Therefore, it has been a problem for the rolling bearing to suppress an increase in pressure inside the bearing when the sealing device is press-fitted.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a rolling bearing capable of suppressing an increase in pressure inside the bearing when the sealing device is press-fitted.

In order to solve the above problems, the structural features of the rolling bearing according to claim 1 are: an outer ring member having a fixed raceway surface fixed to a vehicle body side member of the vehicle; and an inner ring member having a rotation side raceway surface. A rolling element disposed in an annular space between the outer ring member and the inner ring member, and a seal disposed at both ends in the axial direction of the annular space to seal the annular space and constitute a bearing internal space A rolling bearing comprising a device,
The outer ring member has at least one communication hole that communicates the bearing inner space and the bearing outer space radially outward from the outer peripheral surface of the outer ring member, and the communication hole is sealed by the vehicle body side member. It is to be stopped.

  According to the rolling bearing of the first aspect, since the communication hole that connects the bearing inner space and the bearing outer space is formed in the outer ring member, an increase in pressure inside the bearing when the sealing device is press-fitted can be suppressed. . Further, in this rolling bearing, since the outer ring member is fixed to the vehicle body side member of the vehicle and the communication hole is sealed, the inside of the bearing can be sealed.

  The structural feature of the rolling bearing according to claim 2 is that the communication hole is disposed below the axis of the outer ring member when the outer ring member mounted in the vehicle is viewed in an axial cross section. .

  According to the rolling bearing of the second aspect, since the communication hole is disposed on the lower side with respect to the axis of the outer ring member when the outer ring member mounted in the vehicle is viewed in the axial cross section, foreign matter can be prevented from entering the bearing. It is possible to prevent and improve the sealing performance inside the bearing, and to suppress an increase in pressure inside the bearing when the sealing device is press-fitted.

  ADVANTAGE OF THE INVENTION According to this invention, the rolling bearing which can suppress the pressure rise inside a bearing when press-fitting a sealing device can be provided.

It is a longitudinal cross-sectional view of the hub unit provided with the rolling bearing which is the 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the hub unit provided with the rolling bearing which is the 2nd Embodiment of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a rolling bearing of the present invention is embodied will be described with reference to the drawings.
[First Embodiment]
First, a rolling bearing according to a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a longitudinal sectional view of a hub unit 1 including a rolling bearing according to a first embodiment of the present invention. In the following description, the vehicle inner side indicates the left side in FIG. 1, and the vehicle outer side indicates the right side in FIG.

  The hub unit 1 is, for example, for a front wheel of a front wheel drive vehicle (for a drive shaft), and has a double-row outward angular ball bearing structure. Specifically, the hub unit 1 includes an outer ring 2 (outer ring member) fixed to a knuckle 20 (vehicle body side member) on the vehicle body side, and a tire wheel on the axle side that is disposed coaxially with the central axis 01 of the outer ring 2. (Not shown) and an inner shaft 3 (inner ring member) fixed to the brake disc rotor 30, and an inner ring 4 fitted on the outer peripheral surface of a fitting portion 3 a formed integrally with the vehicle inner side end of the inner shaft 3 A double row ball 5 (rolling element) disposed in the circumferential direction between the outer ring 2 and the inner shaft 3 and the inner ring 4 is provided.

  On the inner peripheral surface of the outer ring 2, a raceway surface 2a for balls 5 arranged on the vehicle inner side and a raceway surface 2b for balls 5 arranged on the vehicle outer side are formed. A vehicle body mounting flange portion 2 c is formed on the outer peripheral surface of the outer ring 2 so as to protrude outward in the radial direction.

  A raceway surface 3b is formed on the outer peripheral surface of the inner shaft 3 so as to be opposed to the raceway surface 2b of the outer ring 2. A wheel mounting flange is formed so as to protrude radially outward from the raceway surface 3b. Part 3c is formed.

  The inner ring 4 is press-fitted into the fitting portion 3a and integrated with the fitting portion 3a. On the outer peripheral surface of the inner ring 4, a raceway surface 4 a that faces the raceway surface 2 a of the outer ring 2 is formed.

An annular space 10 for arranging balls 5 as rolling elements is formed between the outer ring 2 and the inner shaft 3 and the inner ring 4. In the annular space 10, an annular sealing device 7 in which a metallic annular member and an annular elastic member are combined is disposed on the vehicle outer side. Further, an annular sealing device 8 in which a metallic annular member and an annular elastic member are combined is disposed on the vehicle inner side.
The sealing device 7 and the sealing device 8 constitute a bearing inner space 6 that is sealed in a state in which relative rotation between the outer ring 2 and the inner shaft 3 and the inner ring 4 is allowed.

A communication hole 9 that communicates from the bearing internal space 6 to the bearing external space 11 is formed in the outer ring 2 below the central axis 01 (axis) of the hub unit 1.
The communication hole 9 is configured to be disposed below the central axis 01 (axis) of the outer ring 2 when the outer ring 2 in the vehicle mounting posture is viewed in an axial cross section.
The configuration of the communication hole 9 will be described separately for an opening position 9a on the bearing inner space 6 side and an opening position 9b on the bearing outer space 11 side.
An opening position 9a on the bearing inner space 6 side in the communication hole 9 is a raceway surface on which the double-row balls 5 roll out of the inner peripheral surface of the outer ring 2 when the outer ring 2 in the vehicle mounting posture is viewed in an axial cross section. It is formed between 2a and 2b.
On the other hand, the opening position 9b on the bearing outer space 11 side is formed in the fitting portion 2d located on the vehicle inner side of the vehicle body mounting flange 2c of the outer ring 2 when the outer ring 2 in the vehicle mounting posture is viewed in the axial section. Has been. The fitting portion 2d is a portion that is fitted and fixed to the knuckle 20 on the vehicle body side.

  The hub unit 1 is assembled by assembling the outer ring 2 and the inner shaft 3 and the inner ring 4 and the ball 5, then encapsulating grease in the annular space 10, and finally press-fitting the sealing devices 7 and 8. And When the sealing devices 7 and 8 are press-fitted, the volume of the sealing devices 7 and 8 is pushed out from the bearing inner space 6 to the bearing outer space 11 through the communication hole 9.

  When the hub unit 1 is fixed to the knuckle 20, the communication hole 9 is sealed by the knuckle 20, and the bearing internal space 6 is sealed.

  As described above, according to the hub unit 1 according to the present embodiment, the communication hole 9 is sealed when the hub unit 1 is fixed to the knuckle 20, so that when the sealing devices 7 and 8 are press-fitted, the communication is performed. The hole 9 can suppress an increase in pressure in the bearing internal space 6.

[Second Embodiment]
Next, a rolling bearing according to a second embodiment of the present invention will be described with reference to FIG.
In addition, the same code | symbol may be attached | subjected to the same component as the said 1st Embodiment, and description may be abbreviate | omitted.
FIG. 2 is a longitudinal sectional view of a hub unit 21 including a rolling bearing according to the second embodiment of the present invention. As in FIG. 1, in the following description, the vehicle inner side indicates the left side in FIG. 2, and the vehicle outer side indicates the right side in FIG.

In the second embodiment, the configuration of the opening position of the communication hole on the bearing internal space side is different.
That is, in the first embodiment, the opening position 9a of the communication hole 9 on the bearing inner space 6 side is a double row of the inner peripheral surface of the outer ring 2 when the outer ring 2 in the vehicle mounting posture is viewed in the axial cross section. It showed about the structure currently formed between the track surfaces 2a and 2b where the ball 5 rolls.

As shown in FIG. 2, the opening position 29 a on the bearing inner space 6 side of the communication hole 29 in the second embodiment is the inner peripheral surface of the outer ring 22 when the outer ring 22 in the vehicle mounting posture is viewed in an axial cross section. Of these, it is formed at a portion between the sealing device 8 on the vehicle inner side and the outer ring raceway surface 2a on the vehicle inner side.
The opening position 29b on the bearing outer space 11 side is the same as the opening position 9b in the first embodiment. That is, the outer ring 22 in the vehicle mounting posture is formed in the fitting portion 2d located on the vehicle inner side of the vehicle body mounting flange 2c of the outer ring 22 when viewed in the axial cross section. The fitting portion 2d is a portion that is fitted and fixed to the knuckle 20 on the vehicle body side.
Other configurations are the same as those of the first embodiment.
From the above, the rolling bearing 21 of the second embodiment performs the same function as that of the first embodiment, and can obtain the same actions and effects.

  As mentioned above, although embodiment of this invention was described about 1st, 2nd embodiment, the rolling bearing of this invention is not limited to 1st, 2nd embodiment, It implements with other various forms. It is something that can be done.

  For example, in the above embodiment, the communication holes 9 and 29 are sealed when the hub units 1 and 21 are fixed to the knuckle 20 of the vehicle body. In the case where leakage of grease from the communication holes 9 and 29 or entry of foreign matter from the communication holes 9 and 29 due to the storage and transportation environment is assumed, the sealing devices 7 and 8 are press-fitted, and then the communication holes 9 and 29 are inserted. You may seal by sticking a seal | sticker on the outer peripheral surface of the fitting part 2d.

  In the first and second embodiments, the configuration of the drive wheel has been described. However, the present invention can also be applied to a driven wheel.

1,21 Hub unit (rolling bearing)
2,22 Outer ring (outer ring member)
2d Fitting part 3 Inner shaft (inner ring member)
4 Inner ring (Inner ring member)
5 balls (rolling elements)
6 Bearing inner space 7, 8 Sealing device 9, 29 Communication hole 9 a, 29 a Opening position 9 b on the bearing inner space side, 29 b Opening position 10 on the bearing outer space side Annular space 11 Bearing outer space 20 Knuckle (vehicle body side member)

Claims (2)

An outer ring member fixed to a vehicle body side member of a vehicle and having a fixed raceway surface; an inner ring member having a rotation side raceway surface; and a rolling element disposed in an annular space between the outer ring member and the inner ring member; In a rolling bearing comprising: a sealing device disposed at both ends of the annular space in the axial direction and sealing the annular space to constitute a bearing internal space.
The outer ring member has at least one communication hole that communicates the bearing inner space and the bearing outer space radially outward from the outer peripheral surface of the outer ring member, and the communication hole is sealed by the vehicle body side member. A rolling bearing characterized by being stopped. 2. The rolling bearing according to claim 1, wherein the communication hole is disposed on a lower side with respect to an axis of the outer ring member when the outer ring member in a vehicle mounting posture is viewed in an axial cross section.

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