JP2010230058A - Sealing device and rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device capable of suppressing an atmospheric pressure difference generated between the inside and outside of lips, suppressing the adsorption of the lips with respect to a sliding member of the lips, and suppressing the wear of the lips. <P>SOLUTION: Projecting parts 71, 81 projecting radially outward are formed on annular faces 70, 80 on the external sides of axial lips 51, 52 sliding on an end face 59 in the axial direction of an inner shaft 3. Communication holes 72, 82 are formed at the axial lips 51, 52 for making sealed sides communicate with the external sides of the axial lips 51, 52 and opened at locations in the projecting parts 71, 81 at an interval from circumferential edges of the projecting parts 71, 81. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sealing device. In particular, the present invention relates to a rolling bearing in which a raceway member having a raceway surface includes only a plurality of cylindrical members, a rolling bearing in which a raceway member having a raceway surface includes a shaft member (for example, a rolling bearing for wheels), a water pump, or The present invention relates to a sealing device suitable for use in a motor using a rolling bearing. The present invention also relates to a rolling bearing provided with a sealing device.

  Conventionally, as a sealing device, there is one described in JP 2003-222145 A (Patent Document 1).

  This sealing device seals between an outer ring and an inner shaft in a hub unit (wheel rolling bearing). The sealing device includes a cored bar member and an elastic member fixed to the cored bar member. The cored bar member has a cylindrical fixing portion and a radially extending portion, and the fixing portion is fitted and fixed to the inner peripheral surface of the outer ring. Moreover, the said radial direction extension part is extended in the substantially radial direction of the said fixing | fixed part from the said fixing | fixed part.

  On the other hand, the elastic member has a base, two axial lips, and a grease lip, and the base is fixed to the radially extending portion. Each of the axial lips extends from the base portion and slides on an end surface of the inner shaft in the axial direction. The grease lip extends from the base inward in the radial direction and on the opposite side of the end surface of the inner shaft in the axial direction, and is spaced from the outer peripheral surface of the inner shaft. ing. The grease lip and the outer peripheral surface of the inner ring constitute a labyrinth seal.

Japanese Patent Laying-Open No. 2003-222145 (FIG. 1)

  In the sealing device having the above configuration, abnormal wear occurs in the axial lip due to the following phenomenon, or the surface pressure of the axial lip against the end surface of the inner shaft increases, and torque is generated due to the large surface pressure. May increase.

  Specifically, when a vehicle or the like equipped with this hub unit is operated and the temperature of the sealed space sealed by the sealing device rises, the air in the sealed space passes through the sealing device and is discharged outside. After that, when the vehicle or the like stops and the temperature in the sealed space decreases, the pressure in the sealed space becomes negative with respect to the external atmospheric pressure. May be pressed against the end surface of the inner shaft, and the axial lip may be attracted to the end surface of the inner shaft. Then, due to the adsorption of the axial lip to the end surface of the inner shaft, the tip of the axial lip may be abnormally worn, shortening the life of the axial lip, increasing the temperature, or generating abnormal noise. is there. In addition, due to the adsorption of the axial lip to the end surface of the inner shaft, the contact surface pressure of the axial lip with respect to the end surface of the inner shaft may increase, and the torque may increase.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sealing device that can suppress the pressure difference generated between the inside and outside of the lip, suppress the adsorption of the lip to the sliding member of the lip, and suppress the wear of the lip. . Moreover, this invention is providing a rolling bearing provided with such a sealing device.

In order to solve the above problems, the sealing device of the present invention is
A cored bar member having a cylindrical fixing part and a radially extending part extending from the fixing part in a substantially radial direction of the fixing part;
An elastic member fixed to the cored bar member,
The elastic member is
A base fixed to the radially extending portion of the core member;
An annular lip extending from the base,
The above lip
A protrusion located on the outer annular surface opposite the sealing side;
The projecting portion has a communication hole that opens at a position spaced from the periphery of the projecting portion and communicates the sealing side with the outside.

  According to the present invention, since the lip has a communication hole that communicates the sealed side and the outside side, the temperature of the sealed side sealed by the sealing device is increased by driving a vehicle or the like equipped with the sealing device of the present invention. When the temperature inside the sealed space becomes higher than the outside temperature and the pressure inside the sealed space becomes larger than the outside pressure, the air located on the sealed side of the lip is moved to the outside of the lip through the communication hole. It can move, and the pressure difference inside and outside the sealing device can be reduced. Therefore, in this case, unlike the conventional sealing device, since the lip hardly floats, when the lubricant (grease etc.) exists on the sealing side of the lip, the lubricant (grease etc.) It rarely leaks to the outside of the lip through the gap that would have been generated when it surfaced.

  On the other hand, a vehicle or the like equipped with the sealing device of the present invention stops after operation, and after the temperature on the sealed side sealed by the sealing device is once higher than the outside air temperature, the temperature is about the outside air temperature. If the pressure in the sealed space decreases and the pressure in the sealed space becomes smaller than the external pressure, the air located outside the lip can move to the sealed side of the lip through the communication hole. The pressure difference inside and outside the sealing device can be reduced. Therefore, in this case, since the negative pressure of the air on the sealed side with respect to the atmospheric pressure does not increase, lip adsorption to the sliding member (ring ring or slinger) may occur based on the negative pressure. Absent. Therefore, the abnormal wear of the lip does not occur, and the wear of the lip can be remarkably suppressed. Further, the lip is not attracted to the sliding member, and the contact surface pressure of the lip against the sliding member is not excessive, so that the torque is not increased.

  Further, according to the present invention, since the communication hole opens at a position spaced from the peripheral edge of the protrusion in the protrusion of the annular surface, an external foreign matter (such as muddy water) is formed through the communication hole. ) Is difficult to move to the sealing side of the lip. If the opening of the communication hole intersects the periphery of the protrusion, foreign matter such as muddy water is likely to collect at the periphery of the protrusion, so the air pressure on the sealed side is negative relative to the atmospheric pressure. When the pressure is reached, a problem occurs because the foreign matter accumulated on the periphery of the protrusion is sucked into the space on the sealed side of the lip through the communication hole.

The rolling bearing of the present invention is
A sealing device of the present invention;
A first race member having a raceway surface located on a seal side with respect to the sealing device, wherein the fixing portion of the core member of the sealing device is fixed;
A second raceway member having a raceway surface located on a sealing side with respect to the sealing device, wherein the lip of the elastic member of the sealing member slides;
A rolling element is provided between the raceway surface of the first raceway member and the raceway surface of the second raceway member.

  According to the present invention, wear of the sealing device can be suppressed and torque can be reduced.

  According to the sealing device of the present invention, wear of the lip can be suppressed and torque can be suppressed.

It is sectional drawing of the axial direction of the rolling bearing for wheels which is 1st Embodiment of this invention. It is a partial expanded sectional view of the 1st sealing device periphery in FIG. FIG. 3 is an enlarged schematic cross-sectional view around a protruding portion of a first axial lip in FIG. 2. It is an expanded sectional view explaining the sealing device of the modification of the sealing device of 1st Embodiment.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a sectional view in the axial direction of a wheel rolling bearing according to a first embodiment of the present invention.

  The wheel rolling bearing includes an outer ring 2 as a first race member, an inner shaft 3 as a second race member, an inner ring 4, a plurality of first balls 5, a plurality of second balls 6, and the first embodiment. A first sealing device 8 and a second sealing device 9 are provided. The said 1st ball | bowl 5 and the 2nd ball | bowl 6 comprise a rolling element.

  The inner shaft 3 has a disc-shaped brake disk mounting flange 10 extending in the radial direction for mounting the brake disk 11 at one end in the axial direction. A plurality of bolt through holes are formed on a concentric circle centered on the approximate center of the brake disk mounting flange 10. With the brake disk 11 in contact with the brake disk mounting flange 10 and with the wheel member 13 in contact with the brake disk 11, an end surface of the wheel member 13 opposite to the brake disk 11 side; The brake disk mounting flange 10 is fixed with a plurality of bolts 15.

  An inner ring 4 is externally fitted and fixed to the other axial end portion of the inner shaft 3. An angular type raceway groove 16 as a raceway surface is formed between the inner ring 4 and the brake disc mounting flange 10 in the inner shaft 3. An angular type raceway groove 17 as a raceway surface is formed on the outer peripheral surface of the inner ring 4.

  The outer ring 2 is disposed on the other end side of the brake disc mounting flange 10 in the inner shaft 3 so as to face the inner shaft 3 in the radial direction. The outer ring 2 has a vehicle body side mounting flange 14 extending in the radial direction on the other end side in the axial direction. A plurality of bolt through holes for inserting bolts for attaching the vehicle body side mounting flange 14 to the vehicle body side (knuckle) are formed in the disk-shaped vehicle body side mounting flange 14. The outer ring 2 has an angular first raceway groove 26 as a first raceway surface and an angular second raceway groove 27 as a second raceway surface, which are spaced apart in the axial direction on the inner peripheral surface of the outer ring 2. is doing. The first track groove 26 is located on the one end side with respect to the second track groove 27.

  The plurality of first balls 5 are spaced by a predetermined interval in the circumferential direction while being held by the cage 18 between the raceway groove 16 of the inner shaft 3 and the first raceway groove 26 of the outer ring 2. Are arranged. The plurality of second balls 6 are spaced by a predetermined interval in the circumferential direction while being held by the cage 19 between the raceway groove 17 of the inner ring 4 and the second raceway groove 27 of the outer ring 2. Has been placed.

  The first sealing device 8 is disposed in the vicinity of the opening on the one end side (the brake disc mounting flange 10 side) in the axial direction between the inner shaft 3 and the outer ring 2. The first sealing device 8 seals the opening on the one end side between the inner shaft 3 and the outer ring 2.

  On the other hand, the second sealing device 9 is disposed between the inner ring 4 and the outer ring 2 in the vicinity of the opening on the other end side (the vehicle body mounting flange 14 side) in the axial direction. The second sealing device 9 seals the opening on the other end side between the inner ring 4 and the outer ring 2.

  FIG. 2 is a partially enlarged cross-sectional view around the first sealing device 8 in FIG.

  As shown in FIG. 2, the first sealing device (hereinafter simply referred to as a sealing device) 8 includes a metal cored bar member 40 and a rubber elastic member 41, and the cored bar member 40 has a cylindrical shape. The fixed portion 60 and the radially extending portion 61 are provided. The fixing portion 60 is fitted and fixed to the end of the inner peripheral surface of the outer ring 2 on the brake disc mounting flange 10 side. The radially extending portion 61 extends from the fixed portion 60 in the substantially radial direction of the fixed portion 60.

  On the other hand, the elastic member 41 has a block-like base portion 50, an annular first axial lip 51, an annular second axial lip 52, and an annular radial lip 53, and the base portion 50 is formed on the radially extending portion 61. It is fixed.

  The first axial lip 51 is located on the outer side in the radial direction than the second axial lip 52. Each of the first axial lip 51 and the second axial lip 52 extends from the base portion 50 to the brake disc mounting flange 10 side in the axial direction and to the outer ring 2 side in the radial direction (outward side in the radial direction). . Each of the first axial lip 51 and the second axial lip 52 slides on the end face 59 on the first ball 5 side in the axial direction of the brake disk mounting flange 10.

  On the other hand, the radial lip 53 extends from the base portion 50 to the first ball 5 side in the axial direction and to the inner side in the radial direction. The radial lip 53 slides on the outer peripheral surface of the inner shaft 3.

  The first axial lip 51 has a plurality of protrusions 71 and a plurality of communication holes 72. The plurality of projecting portions 71 are arranged at substantially the same position in the circumferential direction at substantially the same position in the axial direction on the annular surface 70 on the opposite side (radially outward side) of the first axial lip 51. Has been placed. Each of the protrusions 71 protrudes radially outward from the annular surface 70.

  Each of the communication holes 72 communicates the space on the outside of the first axial lip 51 and the space on the sealed side of the first axial lip 51. The number of communication holes 72 is equal to the number of protrusions 71.

  The second axial lip 52 has a plurality of protrusions 81 and a plurality of communication holes 82. The plurality of projecting portions 81 are provided at substantially the same position in the circumferential direction at substantially the same position in the axial direction on the annular surface 80 on the side opposite to the sealing side of the second axial lip 52 (outward side in the radial direction). Has been placed. Each protrusion 81 protrudes outward in the radial direction of the inner shaft 3 from the annular surface 80.

  Each of the communication holes 82 communicates the space on the outside of the second axial lip 52 and the space on the sealing side of the second axial lip 52. The number of communication holes 82 is equal to the number of protrusions 81.

  FIG. 3 is an enlarged schematic cross-sectional view around the protrusion 71 of the first axial lip 51 of FIG.

  As shown in FIG. 3, each protrusion 71 has a substantially semicircular cross-sectional shape and a substantially hemispherical shape. The communication hole 72 extends in a substantially radial direction of the inner shaft 3 (see FIG. 2). The communication hole 72 is open at the center of the projecting portion 71, specifically, at the portion of the projecting portion 71 that is located on the outermost side in the radial direction. The opening on the protruding portion 71 side of the communication hole 72 is located at a distance from the peripheral edge 90 formed of the closed curve of the protruding portion 71. As described above, when the opening on the protruding portion 71 side of the communication hole 72 is located at a distance from the peripheral edge 90 of the protruding portion 72, the foreign matter A such as muddy water is directed in the direction of the arrow in FIG. Movement, that is, movement of the foreign matter A such as muddy water toward the peripheral edge 90 of the protrusion 72 is promoted. Accordingly, the foreign matter A is less likely to enter the communication hole 72.

  Although not described with reference to an enlarged view, each projection 81 (see FIG. 2) of the second axial lip 52 (see FIG. 2) is also substantially semicircular like the projection 71 of the first axial lip 51. It has a cross-sectional shape and a substantially hemispherical shape. The communication hole 82 (see FIG. 2) extends in the substantially radial direction of the inner shaft 3. The communication hole 82 is open at the center of the projecting portion 81, specifically, at the portion of the projecting portion 81 that is located on the outermost side in the radial direction. The opening on the projecting portion 81 side of the communication hole 82 is located at a distance from the periphery of the projecting portion 81 formed by the closed curve.

  According to the sealing device 8, the axial lips 51, 52 have the communication holes 72, 82 that connect the sealing side of the axial lips 51, 52 to the outside. When the temperature of the sealing side sealed by the sealing device 8 becomes higher than the external temperature and the pressure in the sealing chamber (ball arrangement chamber) becomes larger than the external pressure, each axial lip 51 and 52, the air located on the sealed side of the axial lips 51 and 52 can move to the outside of the axial lips 51 and 52 through the communication holes 72 and 82, and the pressure difference between the inside and outside of the sealing device 8 can be reduced. Can be relaxed. Accordingly, in this case, unlike the conventional sealing device, the axial lips 51 and 52 hardly float, so that the lubricant (grease or the like) positioned on the sealing side of the axial lips 51 and 52 is used as the axial lips 51 and 52. Leaks to the outside of the axial lips 51, 52 through the gaps that would have been generated.

  On the other hand, after the vehicle equipped with the sealing device 8 stops after driving and the temperature on the sealed side sealed by the sealing device 8 once becomes higher than the outside air temperature, the temperature decreases to the temperature of the outside air temperature. When the pressure in the sealed chamber becomes smaller than the external pressure, the air located on the outer side of the axial lips 51, 52 is brought to the sealed side of the axial lips 51, 52 through the communication holes 72, 82. The pressure difference between the inside and outside of the sealing device 8 can be reduced. Therefore, in this case, there is no difference in atmospheric pressure between the atmospheric pressure and the air pressure on the sealed side. Therefore, unlike the conventional example, the axial lips 51 and 52 are attracted to the end face 59 (see FIG. 2) of the inner shaft 3. There is nothing. Therefore, the abnormal wear of the axial lips 51 and 52 does not occur, and the wear of the axial lips 51 and 52 can be remarkably suppressed. Further, the axial lips 51, 52 are not attracted to the end surface 59 of the inner shaft 3, and the contact surface pressure of the axial lips 51, 52 to the end surface 59 of the inner shaft 3 does not become excessive. Torque based on the contact surface pressure does not increase.

  Further, according to the sealing device 8 of the above-described embodiment, the communication holes 72 and 82 are opened in the protruding portions 71 and 81 at locations spaced from the peripheral edge 90 (see FIG. 3) of the protruding portions 71 and 81. Therefore, foreign matter (such as muddy water) does not move to the sealing side of the axial lips 51 and 52 through the communication holes 72 and 82. If the opening of the communication hole intersects the periphery of the protrusion, foreign matter such as muddy water is likely to collect at the periphery of the protrusion, so the air pressure on the sealed side is negative relative to the atmospheric pressure. When the pressure is increased, foreign matter collected on the periphery of the protrusion is drawn into the space on the sealed side of the lip through the communication hole and sucked in, so that the space where the balls 5, 6 and the raceway surface exist is contaminated. It will be.

  In the sealing device 8 of the above embodiment, the radial lip 53 does not have a communication hole, but a protruding portion and a communication hole may be formed on the radial lip. In this case, the pressure difference between the atmospheric pressure in the sealed chamber and the external atmospheric pressure can be relaxed more efficiently and quickly. As described above, in the present invention, when there are a plurality of lips, it is possible to quickly and efficiently reduce the atmospheric pressure between the outside and the sealed chamber. Therefore, it is preferable that all the lips have communication holes.

  Further, in the sealing device 8 of the above-described embodiment, the protrusions 71 and 81 provided with the communication holes 72 and 82 are provided on the axial lips 51 and 52, and the annular surfaces 70 and 80 on the outer side of the axial lips 51 and 52. In the present invention, a plurality of parts are provided at substantially equal intervals in the circumferential direction at the same position in the axial direction. In addition, a protrusion provided with a plurality of communication holes may be provided, and a protrusion provided with a plurality of communication holes at equal intervals in the circumferential direction at different locations in the axial direction of the annular surface toward the outside of at least one lip. In addition, a projecting portion in which a plurality of communication holes are provided at random may be provided on the outer annular surface of at least one lip. In the present invention, at least one lip may be provided with a protruding portion provided with only one communication hole.

  In the sealing device 8 of the above embodiment, the protrusions 71 and 81 and the communication holes 72 and 82 are provided only on the axial lips 51 and 52. However, in the present invention, at least one of the axial lips and the radial lip are provided. You may provide a protrusion part and a communicating hole in at least one of these. Moreover, in this invention, you may provide a protrusion part and a communicating hole only in a radial lip.

  Further, in the sealing device 8 of the above embodiment, the axial lips 51 and 52 provided with the projecting portions 71 and 81 and the communication holes 72 and 82 slide on the axial end surface 59 (see FIG. 2) of the inner shaft 3. In this invention, the lip provided with the protruding portion and the communication hole includes the outer peripheral surface of the inner shaft, the axial end surface of the flange portion of the slinger, the peripheral surface of the slinger, the axial end surface of the inner ring, It may be configured to slide on the outer peripheral surface of the inner ring, the end surface in the axial direction of the outer ring, the inner peripheral surface of the outer ring, or the like.

  In the sealing device 8 of the above embodiment, the non-annular protrusions 71 and 81 are formed on the axial lips 51 and 52. However, in the present invention, one or more annular protrusions are formed on the annular surface on the outer side of the lip. A part may be formed. In this case, the lip may further be formed with one or more communication holes that open at locations other than the peripheral edge of each annular protrusion. In this case, it goes without saying that there are two peripheral edges formed of closed curves in each of the annular protrusions.

  Further, the sealing device 8 of the above embodiment has the two axial lips 51, 52 and the one radial lip 53. However, in the present invention, the sealing device has one or three or more axial lips. It does not have to have an axial lip. Moreover, in this invention, it may have two or more radial lips, and does not need to have a radial lip.

  Moreover, although the sealing device 8 of the said embodiment did not have a labyrinth seal, this invention may have a labyrinth seal.

  Further, in the wheel rolling bearing described above, the sealing device 8 of the present invention is disposed in the vicinity of the opening on one end side in the axial direction of the ball arrangement chamber. You may arrange | position only in the vicinity of the opening of the moving body arrangement | positioning chamber (lubricant enclosure chamber) of the axial direction both sides, or only the other end side of an axial direction.

  Further, in the sealing device 8 of the above embodiment, the projecting portions 71 and 81 have a substantially semicircular cross section, and the communication holes 72 and 82 extend in the substantially radial direction of the sealing member 8. However, the protrusion may have a shape other than a semicircular cross section, and the communication hole may be inclined with respect to the radial direction of the sealing member.

  FIG. 4 is an enlarged cross-sectional view for explaining the modified example, and is an enlarged cross-sectional view around the second axial lip 152 of the elastic member 141. In FIG. 4, reference numeral 150 denotes a base portion of the elastic member 141.

  In the modification shown in FIG. 4, the same reference numerals are assigned to the same components as those in the above embodiment, and the description thereof will be omitted.

  As shown in FIG. 4, in this modification, the projecting portion 181 has a substantially elliptical cross section and projects in a direction inclined by an angle θ with respect to the radial direction of the sealing device 108. The communication hole 182 has a linear cross-sectional shape and extends in a direction inclined by an angle θ with respect to the radial direction of the sealing device 108. As described above, when the projecting portion has a substantially oval cross section and the communication hole 182 extends in a direction inclined at an angle θ with respect to the radial direction of the sealing device 108, the foreign matter from the radial direction of the sealing device 108 is obtained. The structure can be strong against intrusion. In addition, it cannot be overemphasized that a protrusion part may have what kind of cross-sectional shape, and it cannot be overemphasized that a communicating hole may be a bending linear shape or a curve shape instead of a linear shape.

  When there are a plurality of lips and no protrusions and communication holes are provided on all the lips, it is preferable that the protrusions and the communication holes are provided on lips that have a large pressure difference on both sides and are likely to be reversed. This is because it is possible to prevent the lip from being reversed.

  Moreover, in the said embodiment, although the rolling bearing was a rolling bearing for wheels which has the inner shaft 3, the rolling bearing of this invention is a structure which a member which has a raceway surface consists only of multiple (2 or more) cylindrical members. It may be. Also. The rolling bearing of the present invention may be a water pump, a motor, or the like, and may be any rolling bearing having a rolling element and a raceway surface (in this specification, a rolling bearing is referred to as a rolling element). , Defined as a device having a raceway surface on which this rolling element rolls). Further, in the rolling bearing of the present invention, the rolling elements may not be balls but may be rollers, or may be both balls. The rolling element is a roller, including a case where the rolling element is a tapered roller, a case where it is a cylindrical roller, and a case where it is a convex roller, but when the rolling element is a roller, the rolling element is a tapered roller. And preferred. In the rolling bearing of the present invention, the first race member may be an integral member or a plurality of members, and the second race member may be an integral member or a plurality of members. May be. In the rolling bearing of the present invention, the rolling elements may be arranged in a single row, or the rolling elements may be arranged in two or more rows.

2 outer ring 3 inner shaft 4 inner ring 5 first ball 6 second ball 8,108 sealing device 40 core metal member 41,141 elastic member 50,150 base 51 first axial lip 52,152 second axial lip 60 fixing portion 61 radially extending portion 70 annular surface of the first axial lip 71 projecting portion of the first axial lip 72 communicating hole of the first axial lip 80 annular surface of the second axial lip 81,181 projecting portion of the second axial lip 82, 182 Communication hole of second axial lip 90 Perimeter of protrusion

Claims (2)

A cored bar member having a cylindrical fixing part and a radially extending part extending from the fixing part in a substantially radial direction of the fixing part;
An elastic member fixed to the cored bar member,
The elastic member is
A base fixed to the radially extending portion of the core member;
An annular lip extending from the base,
The above lip
A protrusion located on the outer annular surface opposite the sealing side;
A sealing device, comprising: a communicating hole that opens at a location spaced from the periphery of the projecting portion in the projecting portion and communicates the sealed side with the outside. A sealing device according to claim 1;
A first race member having a raceway surface located on a seal side with respect to the sealing device, wherein the fixing portion of the core member of the sealing device is fixed;
A second raceway member having a raceway surface located on a sealing side with respect to the sealing device, wherein the lip of the elastic member of the sealing member slides;
A rolling bearing comprising: a rolling element positioned between the raceway surface of the first raceway member and the raceway surface of the second raceway member.

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