JP2009287596A5 - - Google Patents

Description

Sealing device for rolling bearing

  The present invention relates to a rolling bearing sealing device. Specifically, the present invention relates to a rolling bearing sealing device in which a space between an inner ring and an outer ring is covered with a seal, and a slinger is provided outside the seal.

  Bearings for idlers used in engine peripheral accessories for automobiles, for example, bearings used in idler pulleys, have an annular seal to prevent foreign matter such as water and dust from entering the bearings. A sealing device is provided to cover the space between the outer ring and the inner ring. Here, in this type of bearing, since the inner ring and the outer ring rotate relative to each other, the seal cannot be completely fixed to the outer ring and the inner ring. Therefore, it is necessary to allow relative rotation of the inner ring and the outer ring as a configuration in which the outer periphery of the seal is fixed to the outer ring and a seal lip is provided on the inner periphery of the seal to make sliding contact with the inner ring.

Since the idler bearing is used at high speed rotation, the seal lip needs to be a light contact type having a small amount of interference to prevent heat generation at the sliding portion of the seal. Also, in the idler bearing, the outer ring rotates at a high speed, so the seal fixed to the outer ring also rotates at a high speed, the seal lip is deformed by the centrifugal force of rotation, and the interference of the seal lip is further reduced, further reducing the sealing performance. .
Therefore, simply sealing the space between the outer ring and the inner ring does not provide sufficient sealing against water and dust from the outside, and prevents water and dust from entering the bearing from between the seal lip and the inner ring. Is difficult.
Therefore, a sealing device has been proposed in which a shielding plate called a slinger is provided outside the seal so that water and dust do not directly hit the seal.

  For example, Japanese Patent Application Laid-Open No. 11-230179 (Patent Document 1) describes a rolling bearing provided with a conventional seal and slinger (see FIG. 1 of Patent Document 1). According to this technique, by providing a slinger outside the seal, foreign matters such as water and dust do not directly hit the seal, so that the sealability of the bearing is improved. However, since there is a gap between the slinger and the outer ring and between the seal and the slinger, the sealing performance is not perfect.When used in an environment where a large amount of water is directly applied, sufficient sealing performance is required. It is difficult to secure.

Therefore, a method has been proposed in which an annular protrusion is formed on the side surface of the seal on the slinger side, and the protrusion is slidably contacted with the slinger to improve the sealing performance of the bearing. For example, Japanese Patent Laying-Open No. 2006-258131 (Patent Document 2) discloses a rolling structure in which an auxiliary seal lip protruding outward from a bearing from an elastic member of a sealing device (corresponding to the above-described seal) is in sliding contact with a side surface of a slinger. A bearing is described.
FIG. 5 shows a rolling bearing 110 having a sealing device 115 substantially the same as the sealing device described in Patent Document 2. The sealing device 115 of the rolling bearing 110 includes an annular cored bar 116 and an annular elastic member 117 fixed to the cored bar, and the outer peripheral edge 117a of the elastic member 117 is locked to the outer ring 111 by press fitting or the like. This is fixed to the outer ring 111. A main seal lip 117 b is formed on the inner side surface of the inner peripheral edge of the elastic member 117 and is in sliding contact with the side surface 112 c of the inner ring 112. Further, the elastic member 117 is formed with a sub seal lip 117c and a grease seal lip 117d on the inner surface radially outward from the main seal lip 117b, and is disposed in close proximity to the side surface 112c of the inner ring 112. Further, the elastic member 117 is formed with an auxiliary seal lip 117e protruding outward in the axial direction on the outer surface radially outward from the main seal lip 117b. The auxiliary seal 117e is in sliding contact with the side surface 122a of the slinger 122 which is an annular member disposed adjacent to the inner ring 112.
According to the technique described in Patent Document 2, the auxiliary seal lip 117e provided radially outward from the main seal lip 117b is in sliding contact with the side surface 122a of the slinger 122, so that foreign matters such as water and dust are in contact with the main seal lip 117b. Therefore, it is considered that the waterproofness and dustproofness are improved and the sealing performance of the bearing can be improved.
Japanese Patent Laid-Open No. 11-230279 JP 2006-258131 A

However, in the sealing device 115 described in Patent Document 2, the auxiliary seal lip 117e is disposed and supported on the core metal 116. Therefore, if the auxiliary seal lip 117e has a large tightening margin at the initial stage of attachment of the slinger 122 and the auxiliary seal lip 117e is in strong sliding contact with the slinger 122, the metal core 116 may be pushed by the auxiliary seal lip 117e and deformed. It is done. Then, the sliding contact pressure of the main seal lip 117b on the inner diameter side of the auxiliary seal lip 117e on the sealing device 115 with respect to the inner ring 112 increases, and the seal performance of the main seal lip 117b may deteriorate due to early wear. .
Here, if the tightening margin between the slinger 122 and the auxiliary seal lip 117e is large, torque loss occurs, but the problem of torque loss is solved by wear of the auxiliary seal lip 117e. However, the deformation of the metal core 115 that occurs before the auxiliary seal lip 117e is worn is not eliminated.

  Therefore, the problem to be solved by the present invention is to prevent the core metal of the seal from being deformed and to prevent foreign matters such as water and dust that have entered between the seal and the slinger from entering the inside of the bearing. It is to improve the sealing performance of the bearing.

To solve the above problem, a rolling bearing sealing device according to the present invention includes a seal which rotates with the outer ring is fixed to the outer ring, and a slinger disposed outwardly of the seal, the bearing at the outer diameter side of the slinger A rolling bearing sealing device opened to the outside,
The seal has a structure in which the outer side of the bearing of the metal core is covered with an elastic member, and a seal lip that is in sliding contact with the inner ring is formed inside the bearing at the inner peripheral edge of the seal, and is more radial than the seal lip of the seal A conical side lip that is inclined from the radially outer side to the outer side of the bearing and expands the diameter of the outer side of the bearing is formed by an elastic member on a side surface facing the slinger outside the bearing. A bowl-shaped groove is formed on the outer diameter side of the root part,
In the rotational state of the bearing, the tip of the side lip is configured to be in non-contact with the slinger ,
A front end surface whose surface is perpendicular to the axial direction is formed at the front end of the side lip, and a flat portion perpendicular to the axial direction is formed on the side surface of the slinger facing the front end surface. And the space between the flat portions is narrow, and the tip surface and the flat portion form a labyrinth,
When the bearing is stationary, the tip of the side lip, which is upward when the bearing is stationary, falls down by its own weight and comes into contact with the flat portion of the slinger .

According to the inventions of this, the side lip is formed on the side facing the slinger of the seal. In the rotating state of the bearing, the tip of the seal is not in contact with the slinger, so the tip of the seal and the slinger form a labyrinth, and foreign matters such as water and dust that have entered between the seal and the slinger from the outer diameter side of the slinger Intrusion into the inner diameter side of is suppressed. In the present invention, “non-contact” is used as a concept including a case where contact is made with zero contact force. When the tip of the seal is in contact with the slinger with zero contact force, the gap between the seal and the slinger is blocked by the side lip, so water or dust that enters between the seal and the slinger from the outer diameter side of the slinger Is prevented from entering the inner diameter side of the bearing. Further, since the side lip and the slinger are not in contact with each other, there is no possibility that the core metal of the seal is deformed, so there is no concern that the sliding contact state with the inner ring of the seal lip is changed by the deformation of the core metal.
Therefore, the seal core can be prevented from being deformed, and foreign matter such as water and dust entering the seal and the slinger side can be prevented from entering the bearing, thereby improving the sealability of the bearing. be able to.

Further, in the rotational state of the shaft receiving the flat portion of the distal end surface and the slinger of the seal of the side lip forms a labyrinth inner diameter foreign objects bearing such as water and dust which enters between the seal and the slinger from the radially outer side of the slinger Intrusion to the side is suppressed. In addition, since the front end surface whose surface is perpendicular to the axial direction is formed at the front end of the side lip, the radial width of the labyrinth is wide and the sealing performance by the labyrinth is enhanced. In addition, when the bearing is stationary, the tip of the side lip that is above when stationary is brought down by its own weight and comes into contact with the flat portion of the slinger, so that the gap between the seal and the slinger is closed by the side lip above the bearing. Therefore, when a large amount of water is applied to the bearing at rest and water enters between the seal and the slinger, the water flows down the bearing along the outer diameter side of the side lip. Intrusion of water into the inner diameter side of the is suppressed.

According to the onset Ming described above, in the rotation state of the bearing, the seal of the side lip, than when there is no slinger and the side lip, in contact at the contact force zero or slinger form an extremely narrow labyrinth In order to close the gap with the slinger, foreign matter such as water or dust that has entered between the seal and the slinger is prevented from entering the inner diameter side of the bearing. Further, since the side lip and the slinger are not in contact with each other, there is no possibility that the core metal of the seal is deformed, so there is no concern that the sliding contact state with the inner ring of the seal lip is changed by the deformation of the core metal. Therefore, the seal core can be prevented from being deformed, and foreign matters such as water and dust that have entered between the seal and the slinger can be prevented from entering the inside of the bearing, thereby improving the sealability of the bearing. Can be made. Also, there is almost no increase in torque due to side lip contact.
Further, in the rotation state of the bearings, the seal of the side lip flat portion of the front end surface and the slinger form a wide labyrinth width in the radial direction, such as water and dust which enters between the seal and the slinger foreign matter bearing Intrusion to the inner diameter side is suppressed. In addition, when the bearing is stationary, the tip of the side lip that is located above when the bearing is stationary collapses due to its own weight, thereby closing the gap between the seal and the slinger. Therefore, when a large amount of water is applied to the bearing at rest and water enters between the seal and the slinger, the water flows down the bearing along the outer diameter side of the side lip. Intrusion of water into the inner diameter side of the is suppressed.

  Hereinafter, the best mode for carrying out the present invention will be described.

First, the configuration of the first embodiment of the present invention will be described.
FIG. 1 shows a partial cross-sectional view of an idler pulley 50 using a rolling bearing 10 provided with a rolling bearing sealing device in a first embodiment of the present invention. FIG. 2 shows an enlarged view of a sealing device portion of the rolling bearing 10 shown in FIG.
As shown in FIGS. 1 and 2, the rolling bearing 10 is an outer ring rotation type single row ball bearing used for an idler pulley 50, and holds an inner ring 12, an outer ring 14, a single row ball 16, and a ball 16. The cage 18 includes a seal 20 that covers the space between the inner ring 12 and the outer ring 14, and a slinger 40 that is provided outside the bearing of the seal 20. Among these components, the inner ring 12, the outer ring 14, the seal 20 and the slinger 40 form a sealing device that seals the rolling bearing 10.

  The seal 20 has an annular shape in which the outer side of the bearing of the metal cored bar 22 is covered with a rubber covering portion 23, and a fixing portion 24 for attaching the seal 20 to the outer ring 14 is formed on the outer peripheral edge portion of the seal 20. Has been. The fixing portion 24 is attached to the seal groove 15 provided on the inner diameter surface of the outer ring 14, and the seal 20 is fixed to the inner diameter surface of the outer ring 14. A seal lip 26 is formed inside the bearing at the inner peripheral edge of the seal 20, and the seal lip 26 is in sliding contact with a sliding contact surface 13 formed perpendicular to the shaft on the outer diameter side of the inner ring 12. When the seal 20 rotates at high speed together with the outer ring 14, the seal lip 26 rotates at high speed while sliding on the sliding contact surface 13 of the inner ring 12. Therefore, the seal lip 26 is in light contact with the sliding contact surface 13.

As shown in FIG. 2, the side surface 28 facing the slinger 40 on the outer side of the bearing more radially outward than the seal lip 26 of the seal 20 has a bearing outer side from the radially outer side at a position closer to the radially outer side. A conical side lip 30 is formed which inclines toward the outer side and expands outside the bearing. A flange-like groove 32 is formed on the outer diameter side of the root portion of the side lip 30 to the side surface 28 of the seal 20. A tip surface 34 whose surface is perpendicular to the axial direction is formed at the tip of the side lip 30, and a flat portion 44 perpendicular to the axial direction is formed on the side surface of the slinger 40 facing the tip surface 34 to rotate the bearing. In the state, the distance between the tip surface 34 and the flat portion 44 is narrow, and the tip surface 34 and the flat portion 44 are configured to form a labyrinth.
In addition, in order to ensure the width | variety of the front end surface 34, it is preferable that inclination | tilt angle (theta) shown to (theta) in FIG.

  FIG. 3A shows an enlarged view of the front end portion of the side lip 30. FIG. 3B shows a modification in which the tip surface 34 is not formed at the tip of the side lip 30. The modification of the side lip 30 is easier in the modified example. In the first embodiment, by providing the tip surface 34 at the tip of the side lip 30, the width in which the distance between the side lip 30 and the slinger 40 is narrowed is widened.

  In the first embodiment, the covering portion 23 of the seal 20, the fixing portion 24, the seal lip 26 and the side lip 30 are integrally formed, but the side lip 30 is formed separately and the side surface of the covering portion 23 of the seal 20. 28 may be adhered. If the side lip 30 is molded separately, it is easy to mold the side lip 30 with a softer material than the covering portion 23. The seal 20 including the side lip 30 is not limited to rubber and may be made of resin.

  In the first embodiment, as described above, the front end surface 34 of the side lip 30 and the flat portion 44 of the slinger 40 are configured to have a narrow gap. However, due to manufacturing variations, the tip surface 34 of the side lip 30 is allowed to be in contact with the flat portion 44 of the slinger 40 in the rotating state of the bearing. When the tip surface 34 and the flat portion 44 come into contact with each other, the side lip 30 falls and deforms inside the bearing, and the contact force of the slinger 40 is absorbed by the side lip 30, so that the covering portion 23 of the seal 20 and the cored bar 22 The structure is such that almost no axial stress is transmitted.

  The slinger 40 is an annular metal plate, and as shown in FIG. 2, the end of the inner periphery is bent in a cylindrical shape toward the inside of the rolling bearing 10 to form a cylindrical portion 42. The slinger 40 is fixed to the inner ring 12 by being press-fitted into the outer diameter side of the inner ring 12. And the front-end | tip part 46 of the outer periphery end of the slinger 40 has a clearance gap between the inner-diameter surface of the outer ring | wheel 14, and forms the opening part 48 with respect to the exterior of a bearing. As described above, the flat portion 44 inside the bearing of the slinger 40 is configured not to contact the side lip 30 of the seal 20 in the rotating state of the bearing.

Next, the function of the rolling bearing sealing device in the first embodiment will be described.
In the rolling bearing 10, the side lip 30 of the seal 20 and the flat portion 44 of the slinger 40 are not in contact with each other. Then, an extremely narrow labyrinth is formed between the front end surface 34 of the side lip 30 and the flat portion 44 of the slinger 40, and water, dust, etc. that have entered between the seal 20 and the slinger 40 from the outer diameter side of the slinger 40 are formed. The entry of foreign matter into the inner diameter side of the bearing is suppressed. Here, since the width in the radial direction of the labyrinth is widened by the tip surface 34 at the tip of the side lip 30, the sealing performance against the intrusion of foreign matter is high.
Further, when the side lip 30 of the seal 20 and the slinger 40 are in contact with each other due to manufacturing variations, the gap between the seal 20 and the slinger 40 is blocked by the side lip 30. Intrusion of foreign matter such as water and dust into the inner diameter side of the bearing is suppressed.

Here, when the side lip 30 comes into contact with the slinger 40, the side lip 30 falls inside the bearing and deforms, so that the contact force of the slinger 40 is absorbed. Therefore, even if the slinger 40 is in contact with the side lip 30, almost no axial stress is transmitted from the covering portion 23 of the seal 20 at the base of the side lip 30 to the core metal 22, and the core metal 22 may be deformed. Absent. Therefore, there is no concern that the portion of the seal lip 26 that is in sliding contact with the inner ring 12 is deformed by the deformation of the core metal 22 and the contact state of the seal lip 26 with the inner ring 12 is not changed. Therefore, in the rolling bearing 10, it is possible to prevent the metal core 22 of the seal 20 from being deformed and to prevent foreign matters such as water and dust that have entered between the seal 20 and the slinger 40 from entering the inside of the bearing. This can improve the sealing performance of the bearing.
The groove 32 at the root portion of the side lip 30 to the seal 20 serves to weaken the rigidity of the root portion of the side lip 30 and facilitate the escape of the side lip 30 from the slinger 40.

  Further, since the diameter of the side lip 30 is increased toward the distal end surface 34, foreign matter such as water or dust is passed to the inner diameter side of the side lip 30 beyond the labyrinth formed by the distal end surface 34 and the flat portion 44 of the slinger 40. When the intrusion occurs, the foreign matter adhering to the inner diameter side of the side lip 30 is likely to be discharged radially outward from the labyrinth gap due to the centrifugal force generated by the rotation of the side lip 30.

In addition, when the rolling bearing 10 is stationary, the side lip 30 of the seal 20 that is upward when stationary is brought down by its own weight and comes into contact with the flat portion 44 of the slinger 40. 40 gaps are closed. At this time, the groove 32 at the base portion of the seal 20 of the side lip 30 serves to weaken the base rigidity of the side lip 30 so that the side lip 30 can easily fall down due to its own weight.
Therefore, when a large amount of water is applied to the rolling bearing 10 at rest and water enters between the seal 20 and the slinger 40, the groove 32 at the base portion of the side lip 30 plays a role of a ridge and enters above the bearing. Since the water flows along the outer diameter side of the side lip 30 and gathers in the groove 32 and flows down the bearing 32 along the groove 32, the intrusion of water from between the seal 20 and the slinger 40 to the inner diameter side of the bearing is suppressed. .

Next, a second embodiment of the present invention will be described.
FIG. 4 shows a partial cross-sectional view of an idler pulley 50A using a rolling bearing 10A provided with a rolling bearing sealing device in a second embodiment of the present invention. As shown in FIG. 4, the rolling bearing 10 </ b> A is an outer ring rotation type double row ball bearing used for the idler pulley 50 </ b> A, and includes an inner ring 12, an outer ring 14, a double row ball 16, and a cage 18 that holds the ball 16. , A seal 20 that covers the space between the inner ring 12 and the outer ring 14, and a slinger 40 provided outside the bearing of the seal 20.

The feature of the second embodiment is that the sealability of the rolling bearing 10A is enhanced by utilizing a part of the structure of the idler pulley 50A of the equipment incorporating the rolling bearing 10A. That is, as shown in FIG. 4, the flange 52 of the idler pulley 50 </ b> A extends outside the bearing of the slinger 40 to the vicinity of the outer diameter surface of the inner ring 12, so that the bearing outer surface of the slinger 40 and the bearing inner surface of the flange 52. It forms a labyrinth.
Further, the width of the outer ring 14 is narrower than the width of the inner ring 12, and the leading end 46 of the slinger 40 extends to the outside of the outer ring 14 near the outer diameter of the outer ring 14 to provide a labyrinth between the outer surface of the outer ring 14 and the inner surface of the slinger 40. Forming. The seal 20 has the same configuration as that of the first embodiment, and is fixed to the outer ring 14 by the fixing portion 24, and the seal lip 26 is in sliding contact with the sliding contact surface 13 of the inner ring 12. The side lip 30 is not in contact with the flat portion 44 of the slinger 40.

  In the second embodiment, the sealing function of the bearing by the side lip 30 and the slinger 40 and the effect thereof are the same as those in the first embodiment, and thus detailed description thereof is omitted. In the second embodiment, in addition to the effects described in the first embodiment, the sealing effect by the labyrinth formed by the flange 52 of the slinger 40 and the idler pulley 50A is added, so that the overall sealing performance of the bearing is improved. To do.

  If the pulley is a press pulley that is formed by deep drawing, a punching process is included, so even if the heel opening diameter is reduced by leaving the heel longer, the heel can be shortened to open the heel. Processing is possible at the same cost even if the diameter is increased. Therefore, the press pulley has a high cost merit for making the hook longer.

In each of the above embodiments, the side lip 30 is formed on the outer side in the radial direction of the side surface 28 of the seal 20, but it may be formed in the center in the radial direction. Further, the shape of the side lip 30 is not limited to a conical shape.
In each of the above embodiments, the slinger 30 is press-fitted into the inner ring 12 and fixed to the inner ring 12. However, the end of the slinger 30 on the inner ring 12 side may be directly fixed to the shaft on the side surface of the inner ring 12. .

In each of the above embodiments, examples of the outer ring rotation type double row ball bearing and the single row ball bearing used for the idler pulley are shown. However, the application of the rolling bearing sealing device according to the present invention is a ball bearing for the idler pulley. Not limited to. The sealing device for a rolling bearing according to the present invention can be applied to an outer ring rotating type rolling bearing in general.
In addition, the rolling bearing sealing device according to the present invention can be implemented in various forms within the scope of the concept of the invention.

It is a fragmentary sectional view of the idler pulley using the bearing provided with the sealing device for rolling bearings in the first embodiment. It is an enlarged view of the part regarding the sealing device for rolling bearings in FIG. (A) is an enlarged view of a 1st Example, (B) is an enlarged view of the front-end | tip part of the side lip of a modification. It is a fragmentary sectional view of the idler pulley which uses the bearing provided with the sealing device for rolling bearings in 2nd Example. It is a figure which shows a prior art.

θ Inclination angle 10, 10A Rolling bearing 12 Inner ring 13 Sliding contact surface 14 Outer ring 15 Seal groove 16 Ball 18 Cage 20 Seal 22 Core 23 Cover 24 Fixing part 26 Seal lip 28 Side face 30 Side lip 32 Groove 34 End face 40 Slinger 42 Cylindrical part 44 Flat part 46 Tip part 48 Opening part 50, 50A Idler pulley 52 鍔

Claims (1)

A rolling bearing sealing device comprising a seal fixed to an outer ring and rotating together with the outer ring, and a slinger disposed on the outer side of the seal, the outer diameter side of the slinger opening to the outside of the bearing,
The seal has a structure in which the outer side of the bearing of the metal core is covered with an elastic member, and a seal lip that is in sliding contact with the inner ring is formed inside the bearing at the inner peripheral edge of the seal, and is more radial than the seal lip of the seal A conical side lip that is inclined from the radially outer side to the outer side of the bearing and expands the diameter of the outer side of the bearing is formed by an elastic member on a side surface facing the slinger outside the bearing. A bowl-shaped groove is formed on the outer diameter side of the root part,
In the rotational state of the bearing, the tip of the side lip is configured to be in non-contact with the slinger ,
A front end surface whose surface is perpendicular to the axial direction is formed at the front end of the side lip, and a flat portion perpendicular to the axial direction is formed on the side surface of the slinger facing the front end surface. And the space between the flat portions is narrow, and the tip surface and the flat portion form a labyrinth,
A rolling bearing sealing device , wherein when the bearing is stationary, the tip of the side lip, which is located upward when the bearing is stationary, falls down by its own weight and comes into contact with the flat portion of the slinger .