JP5733080B2 - 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 is a rolling bearing for a wheel provided with an internal pressure adjusting means which adjusts so that it may 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 inner ring having a raceway surface formed on an outer diameter surface; an outer ring having a raceway surface formed on an inner diameter surface; A sealing device that is disposed at both ends in the axial direction of the bearing inner space between the outer ring and press-fit and seals the bearing inner space;
One of the inner ring and the outer ring is a rotating wheel and the other is a fixed ring,
The sealing device has a fitting portion that fits in an axial end portion of the raceway side peripheral surface of the fixed ring,
In the rolling bearing provided with at least one exhaust groove that communicates the inside of the bearing and the outside of the bearing in the axial direction,
The fitting portion includes an elastic fitting portion that is continuously formed by an elastic member from an end portion on the bearing outer side of the fitting portion in the axial direction to a midway position toward the bearing inner side,
The elastic fitting portion has a predetermined interference with the fixed ring, and gradually reduces the facing distance to the fixed ring from the bearing inner side end toward the bearing outer side end. An angled tooth formed in the direction, and at least one elastic groove that communicates the bearing inner side end and the bearing exterior in the axial direction,
A part of the exhaust groove is formed by the elastic groove part,
After press-fitting the sealing device into the bearing, the teeth are crushed to seal the bearing internal space.

  According to the rolling bearing of the first aspect, the volume which press-fits the sealing device from the start of press-fitting of the sealing device is exhausted from the bearing inner space to the outside of the bearing through the exhaust groove, and from the middle of press-fitting, the exhaust groove and Since the exhaust gas is exhausted to the outside of the bearing through the elastic groove portion, there is no pressure increase inside the bearing. Thereby, the pressure rise inside a bearing when press-fitting a sealing device can be suppressed.

The structural feature of the rolling bearing according to claim 2 is that the fitting portion is integrated with the elastic member from the bearing inner end of the fitting portion to the bearing inner end of the elastic fitting portion. A reinforcing fitting portion that is joined and continuously formed by a reinforcing member that reinforces the elastic member;
The reinforcing fitting portion includes at least one reinforcing groove portion that communicates the bearing inner side and the bearing outer side end portion in the axial direction,
A part of the exhaust groove is formed by the reinforcing groove portion.

  According to the rolling bearing of claim 2, the volume of the press fitting of the sealing device from the start of press fitting of the sealing device is exhausted from the inner space of the bearing to the outside of the bearing through the reinforcing groove portion. Since the exhaust gas is exhausted to the outside of the bearing through the elastic groove portion, there is no pressure increase inside the bearing. Thereby, while suppressing the pressure rise inside a bearing when press-fitting a sealing device, the intensity | strength of a sealing device can be raised with a reinforcement member and a sealing performance can be improved.

  A structural feature of the rolling bearing according to claim 3 is that the elastic fitting portion is formed such that the teeth are continuously formed over the entire circumference of the fitting surface, and a plurality of the elastic groove portions are formed.

  According to the rolling bearing of claim 3, the rolling groove is formed in the reinforcing groove portion formed in the reinforcing fitting portion provided on the bearing inner side of the fitting portion, and the elastic fitting portion provided on the bearing outer side of the fitting portion. It becomes easy to match the elastic groove portion in the circumferential direction, and the inside of the bearing and the outside of the bearing can be reliably communicated, so that an increase in pressure inside the bearing can be reliably suppressed 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 one Embodiment of this invention. (A) is a principal part expanded sectional view of the press-fitting start state of a sealing device in the assembly process of the rolling bearing which is one Embodiment of this invention, (b) is a principal part expanded sectional view of the state in the middle of press-fitting a sealing device. (C) is a principal part expanded sectional view of the press-fitting completion state of a sealing device. (A) is C1 arrow view of the sealing device of FIG. 2 (a) of 1st Embodiment, (b) is C2 arrow view of the sealing device of FIG.2 (b), (c) is a figure. It is a C3 arrow directional view of the sealing device of 2 (c).

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.
FIG. 1 is a longitudinal sectional view of a hub unit 1 having a rolling bearing according to an embodiment of the present invention. This will be described with reference to FIG. 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 (fixed wheel) fixed to the knuckle 20 on the vehicle body side, a tire wheel (not shown) on the axle side, arranged coaxially with the center axis 01 of the outer ring 2, and The inner shaft 4 (inner ring, rotating wheel) fixed to the brake disc rotor 30 and the inner ring 4 (rotating wheel) fitted on the outer peripheral surface of the fitting portion 3a formed integrally with the vehicle inner side end of the inner shaft 3 And a double row of balls 5 arranged in the circumferential direction between the outer ring 2 and the inner shaft 3 and the inner ring 4.

  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 in the radial direction.

  A raceway surface 3b that faces the raceway surface 2b of the outer ring 2 is formed on the outer peripheral surface of the inner shaft 3, and a wheel mounting flange portion 3c that is formed to project in the radial direction further on the vehicle outer side than the raceway surface 3b. 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 for disposing balls 5 as rolling elements is formed between the outer ring 2 and the inner shaft 3 and the inner ring 4, and this annular space is an annular space made of an elastic member on the vehicle outer side. The sealing device 7 is sealed with an annular sealing device 8 made of an elastic member on the vehicle inner side in a state in which relative rotation between the outer ring 2 and the inner shaft 3 and the inner ring 4 is allowed.

  FIG. 2A is an enlarged cross-sectional view of a main part in a press-fitting start state of the sealing device 8 in the assembly process of the rolling bearing according to the embodiment of the present invention, and FIG. FIG. 2C is an enlarged cross-sectional view of a main part of the sealing device 8 in a press-fitted state. 3A is a C1 arrow view of the sealing device 8 of FIG. 2A of the first embodiment, and FIG. 3B is a C2 arrow view of the sealing device 8 of FIG. 2B. FIG. 3 (c) is a C3 arrow view of the sealing device 8 of FIG. 2 (c).

  The sealing device 8 is an annular pack seal and includes a cored bar 81 (reinforcing member), a slinger 84 and an elastic member 82.

  The cored bar 81 is formed by bending a metal plate, and has an L-shaped cross section including a cylindrical cored bar part 81b and an annular cored bar part 81c extending radially inward from the end of the cylindrical cored bar part 81b. Is formed. The cylindrical cored bar 81 b has a reinforcing fitting portion 83 a that fits on the outer ring fitting surface 21 at the axial end of the inner circumference of the outer ring 2 on the outer circumferential surface of the outer ring 2. The reinforcing fitting portion 83a is formed with a reinforcing groove portion 81a that communicates from the bearing inner side end portion P1 to a midway position P2 toward the bearing outer side. As a material of the cored bar 81, for example, SPCC of a cold rolled steel sheet is used.

  The slinger 84 is formed by bending a metal plate such as a rust-proof rolled steel plate, a cylindrical slinger portion 84a, and an annular slinger portion 84b extending radially outward from the end of the cylindrical slinger portion 84a. The cross section is formed into an L-shape. A cylindrical slinger portion 84 a is fitted to the axial end of the inner race 4 on the raceway side. As the material of the slinger 84, for example, stainless steel is used.

  The cored bar 81 and the slinger 84 are combined with the cylindrical cored bar part 81b and the cylindrical slinger part 84a facing each other, and the annular cored bar part 81c and the annular slinger part 84b are combined to form a pack seal. ing.

An elastic member 82 made of rubber is attached to the cored bar 81. The elastic member 82 is a long member extending along the entire circumference of the cored bar 81, and includes a lip 82a that is in sliding contact with the inner peripheral surface of the annular slinger portion 84b of the slinger 84, and a cylindrical slinger portion 84a. It is formed with a predetermined margin between the lip 82b, 82c slidably in contact with the inner peripheral surface and the outer ring 2 from the intermediate position P2 to the bearing outer side end portion P3 in the axial direction. And an elastic fitting portion 83b fitted to the outer ring fitting surface 21 at the circumferential axial end portion.
Here, the fitting portion 83 of the present invention includes a reinforcing fitting portion 83a and an elastic fitting portion 83b.

The elastic fitting portion 83b has an outer diameter that gradually increases from the midway position P2 toward the bearing external side end P3, and has an angled tooth 82d that is continuous in the circumferential direction of the outer peripheral surface, and a midway position P2 and the bearing in the axial direction. And a plurality of elastic groove portions 82e communicating with the outside.
Here, the exhaust groove 85 of the present invention includes a reinforcing groove portion 81a and an elastic groove portion 82e.

  As shown in FIG. 3A, the width W of the reinforcing groove 81a in the circumferential direction is set to the circumferential length of the teeth 82d including at least two peaks, so that the reinforcing groove 81a and the elastic groove 82e are surrounded. It becomes easy to match the direction, and the bearing inner space 6 and the bearing exterior can be reliably communicated with each other via the reinforcing groove 81a and the elastic groove 82e.

  In the assembly process of the hub unit 1, the outer ring 2, the inner shaft 3, the inner ring 4, the ball 5, and the sealing device 7 are assembled, grease is then sealed in the bearing inner space 6, and then the sealing device 8 is press-fitted. At the start of press-fitting of the sealing device 8 shown in FIGS. 2 (a) and 3 (a), the outer ring end portion P10 and the bearing inner side end portion P1 which are axial end outer side end portions of the outer ring fitting surface 21 are provided. Therefore, the volume of the sealing device 8 is exhausted from the bearing inner space 6 to the outside of the bearing through the reinforcing groove 81a and the elastic groove 82e as indicated by arrows B1 and B2, and thereafter the bearing inner space. There is no pressure increase of 6.

  Then, the sealing device 8 continues to be press-fitted while the reinforcing fitting portion 83a is fitted to the outer ring fitting surface 21, and the outer ring is in a state in which the sealing device 8 shown in FIGS. 2 (b) and 3 (b) is being press-fitted. When the end portion P10 coincides with the midway position P2, the volume of the sealing device 8 is exhausted from the bearing inner space 6 to the bearing outer space as shown by the arrow B2 through the reinforcing groove portion 81a and the elastic groove portion 82e. There is no pressure rise in the bearing internal space 6.

  Further, the sealing device 8 continues to be press-fitted while the elastic fitting portion 83b is fitted to the outer ring fitting surface 21, and the outer ring end P10 shown in FIGS. 2 (c) and 3 (c) is the elastic fitting portion 83b. When it coincides with the bearing outer side end portion P3, the press-fitting of the sealing device 8 is finished. In this fitting, the sealing device 8 gradually crushes the chevron teeth 82d of the elastic fitting portion 83b, and the elastic groove portion 82e disappears at the end of press-fitting to seal the bearing internal space 6. Moreover, since the elastic fitting part 83b is formed in the sealing device 8 so that it may spread outward, the tightening allowance on the bearing outer side is increased, and the sealing performance can be improved.

  As described above, according to the hub unit 1 according to the present embodiment, when the sealing device 8 is press-fitted, the exhaust is exhausted to the outside of the bearing through the reinforcing groove 81a and the elastic groove 82e. Absent. Thereby, the pressure rise of the bearing internal space 6 when press-fitting the sealing device 8 can be suppressed.

  In the above embodiment, the strength of the sealing device 8 is increased by the reinforcing metal core 81 to improve the sealing performance. However, the present invention is not limited to this. For example, the shape of the sealing device is small and requires a high strength. Otherwise, the present invention may be applied to a configuration that does not include the cored bar 81.

  Further, in the above-described embodiment, the elastic fitting portion 83b has a configuration in which the chevron teeth 82d are continuously formed on the outer peripheral surface and the elastic groove portions 82e are formed in plural, but the invention is not limited thereto. Two 82d are continuously formed, and one elastic groove 82e is formed between the teeth 82d. When the elastic member 82 is attached to the metal core 81, the reinforcing groove 81a and the elastic groove 82e formed on the metal core 81 are provided. You may apply to the structure which makes these correspond to the circumferential direction.

  Moreover, in the said embodiment, although it was set as the structure provided with the slinger 81, it is not restricted to it, For example, the sealing device consists of a metal core and an elastic member, and it is the structure which the lip of an elastic member slidably contacts with the track surface of a rotating wheel. You may apply.

1: hub unit (rolling bearing), 2: outer ring (fixed ring), 3: inner shaft (inner ring, rotating ring), 4: inner ring (rotating ring), 5: ball, 6: bearing internal space, 7, 8: Sealing device 81: Metal core (reinforcing member) 81a: Reinforcing groove portion 82: Elastic member 82d: Teeth 82e: Elastic groove portion 83: Fitting portion 83a: Reinforcing fitting portion 83b: Elastic fitting portion 84: Slinger, 85: Exhaust groove, P1: Bearing inner side end, P2: Middle position, P3: Bearing outer side end

Claims (3)

An inner ring having a raceway surface formed on an outer diameter surface, an outer ring having a raceway surface formed on an inner diameter surface, and axial ends of a bearing inner space between the inner ring and the outer ring, A sealing device for press-fitting and sealing the space;
One of the inner ring and the outer ring is a rotating wheel and the other is a fixed ring,
The sealing device has a fitting portion that fits in an axial end portion of the raceway side peripheral surface of the fixed ring,
In the rolling bearing provided with at least one exhaust groove that communicates the inside of the bearing and the outside of the bearing in the axial direction,
The fitting portion includes an elastic fitting portion that is continuously formed by an elastic member from an end portion on the bearing outer side of the fitting portion in the axial direction to a midway position toward the bearing inner side,
The elastic fitting portion has a predetermined interference with the fixed ring, and gradually reduces the facing distance to the fixed ring from the bearing inner side end toward the bearing outer side end. An angled tooth formed in the direction, and at least one elastic groove that communicates the bearing inner side end and the bearing exterior in the axial direction,
A part of the exhaust groove is formed by the elastic groove part,
A rolling bearing characterized in that after press-fitting the sealing device into the bearing, the teeth are crushed to seal the bearing internal space. The fitting portion is integrally joined to the elastic member from the bearing inner end of the fitting portion to the bearing inner end of the elastic fitting portion, and is continuously formed by a reinforcing member that reinforces the elastic member. With a reinforced fitting
The reinforcing fitting portion includes at least one reinforcing groove portion that communicates the bearing inner side and the bearing outer side end portion in the axial direction,
The rolling bearing according to claim 1, wherein a part of the exhaust groove is formed by the reinforcing groove portion.   3. The rolling bearing according to claim 1, wherein the elastic fitting portion has the teeth continuously formed over the entire circumference of the fitting surface, and a plurality of the elastic groove portions are formed.

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