JP2009197970A - Sealing device for rolling bearing - Google Patents

Abstract

Provided is a rolling bearing sealing device that further suppresses the entry of foreign matter from an opening of a slinger and can discharge foreign matter that has entered between the seal and the slinger to the outside of the bearing. Further improve the reliability.
A rolling bearing sealing device includes a seal 20 fixed to an outer ring 14 and rotating together with the outer ring 14, and a slinger 30 disposed outside the seal 20. Further, a conical axial lip 26 is formed on the side surface 25 of the seal 20 facing the slinger 30, and the diameter of the seal 20 increases toward the outer side of the bearing so as to come into contact with the slinger 30. A plurality of plate-like fins 28 are formed spaced apart from each other in the circumferential direction. Then, due to the rotation action of the fins 28 due to the rotation of the seal 20, the air pressure between the radially outer seal 20 and the slinger 30 becomes higher than the outside air, and the entry of foreign matter from the outside of the bearing is suppressed.
[Selection] Figure 2

Description

  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. Therefore, it is difficult to prevent water and dust from entering the bearing with only the seal lip.
Furthermore, since the outer ring rotates at a high speed in the idler bearing, 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. . For this reason, 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). FIG. 4 shows a rolling bearing substantially the same as that described in FIG. 1 of Patent Document 1 as the first embodiment. In the rolling bearing 1 described in the first embodiment of Patent Document 1, a seal 5 mounted between the inner ring 2 and the outer ring 3 is mounted on one side in a seal groove 3a provided on the inner diameter surface of the outer ring 3, The other side is in contact with a seal groove 2 a provided on the outer diameter surface of the inner ring 2. A slinger type shield plate 6 is sandwiched and attached between the inner ring 2 and the retaining ring 9 outside the seal 5 in the axial direction (see paragraphs 0007 and 0008 of Patent Document 1).
In Patent Document 1, a shield plate 6 covering the seal 5 is attached to the rolling bearing 1, so that the seal itself does not directly collide with water, foreign matter, or the like. It is described that a labyrinth is formed between the outer ring 3 and a labyrinth is formed between them, and that the seal 5 rotates together with the outer ring 3 so that water and foreign matter are blown out of the bearing by the centrifugal force of the seal 5 (Patent Document). 1 paragraph 0009).

According to the technique described in Patent Document 1, by providing a slinger on the outside of the seal, water and dust do not directly hit the seal, so 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. 2005-325924 (Patent Document 2) discloses a sealing device in which the vicinity of the tip of the side lip 22 extending from the seal ring 2 is slidably in close contact with the inner surface 32a of the seal flange 32 of the slinger 3. (See FIG. 1 of Patent Document 2 and paragraph 0018).
Japanese Patent Laid-Open No. 11-230279 JP 2005-325924 A

  Certainly, the sealing performance of the bearing is improved by forming an annular projection on the side surface of the seal on the slinger side and sliding the projection on the slinger. However, since the seal rotates at a high speed together with the outer ring and rotates relative to the slinger fixed to the inner ring or the shaft, the protrusion of the seal needs to be in light contact with the slinger in order to avoid torque loss due to sliding contact. Therefore, it is difficult to prevent foreign matters from entering the inner diameter side from the contact portion between the seal and the slinger, and the sealing performance is not sufficient. In particular, when used in an environment where a large amount of water is directly applied, water tends to enter the gap between the seal and the slinger from the gap on the outer diameter side of the slinger. Moreover, foreign matters such as water and dust that have once entered between the seal and the slinger tend to stay between the seal and the slinger, and it is difficult to prevent the foreign matter from entering the inside in the radial direction from the contact portion between the seal and the slinger. It becomes. Therefore, even if the gap between the seal and the slinger is closed with the seal protrusion, it is difficult to ensure sufficient sealing performance.

  Therefore, the problem to be solved by the present invention is to suppress the entry of foreign matter such as water and dust from the opening of the slinger between the seal and the slinger, and foreign matter such as water and dust that has entered between the seal and the slinger. Provides a sealing device for a rolling bearing with further improved sealing performance, which can prevent foreign matter entering between the seal and the slinger from being effectively discharged to the outside of the bearing. It is to further improve the reliability.

In order to solve the above-mentioned problems, a rolling bearing sealing device according to the present invention takes the following means.
First, a first invention of the present invention is for a rolling bearing 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, and opened to the outside of the bearing on the outer diameter side of the slinger. A sealing device,
A conical axial lip that increases in diameter toward the outside of the bearing and contacts the slinger is formed on a side surface of the seal that faces the slinger, and a seal is provided at a base portion of the axial lip with respect to the side surface of the seal. A plurality of plate-shaped fins are formed spaced apart in the circumferential direction between the side surfaces of
The air between the seal and the slinger is sent outward in the radial direction by the rotational action of the fin caused by the rotation of the seal, and the pressure between the radially outer seal and the slinger is higher than the outside air, resulting in a pressure difference from the outside air. This prevents foreign matter from entering between the seal and the slinger from the outside of the bearing.

According to the first aspect of the invention, the axial lip formed on the side surface of the seal facing the slinger contacts the slinger and closes the gap between the seal and the slinger. Therefore, foreign matter such as water and dust that has entered between the seal and the slinger through the opening on the outer diameter side of the slinger is prevented from entering near the seal lip on the inner diameter side of the bearing.
Here, a plurality of plate-like fin portions are formed in the root portion of the axial lip on the side surface of the seal so as to be spaced apart from the side surface of the seal in the circumferential direction. Therefore, the air between the seal and the slinger is sent out radially outward by the rotation action of the fin portion caused by the rotation of the seal. The foreign matter in the air is sent outward in the radial direction by the inertial force due to the rotation, and is discharged to the outside of the bearing. Moreover, since air is sent out radially outward, the air pressure between the radially outward seal and the slinger is higher than the outside air. For this reason, a pressure difference occurs between the inside and outside of the opening on the outer diameter side of the slinger, and entry of water, dust, or the like between the seal and the slinger from the outside of the bearing is suppressed. Therefore, the sealing performance of the rolling bearing can be improved and the reliability can be further improved.

Next, a second invention of the present invention is a rolling bearing sealing device according to the first invention,
The fins are formed to be inclined with respect to the radial direction, and the direction of the inclination of the fins is that the foreign matter that has entered between the side surface of the seal and the axial lip with respect to the rotation of the seal is radially outward of the bearing. It is characterized by being directed to the direction of discharge.

  According to the second aspect of the present invention, foreign matter such as water and dust that enters the gap between the seal and the slinger and accumulates in the groove between the side surface of the seal and the axial lip is rotated in the rotational direction of the seal by the inertial force due to the rotational action of the seal. Move in the opposite direction and hit the fin. Here, since the fin is a direction in which the foreign matter is discharged outward in the radial direction of the bearing, the foreign matter is pushed out in the radial direction along the fin and discharged to the outside of the bearing. Therefore, when used in an environment where a large amount of water is applied, the water can be effectively discharged to the outside of the bearing.

According to each invention of the present invention described above, the following effects can be obtained.
First, according to the first invention described above, the air between the seal and the slinger and the foreign matter in the air are sent out radially outward by the rotation of the fin caused by the rotation of the seal. There is. Also, since air is sent radially outward, the air pressure between the seal and the slinger is higher than the outside air in the radially outward direction, so that water and dust can enter the seal and the slinger from the outside of the bearing. Deterred. Therefore, the sealing performance of the rolling bearing can be improved and the reliability can be further improved.
Next, according to the second aspect of the invention, foreign matter such as water or dust that has entered the gap between the seal and the slinger and accumulated in the groove between the side surface of the seal and the axial lip is caused by the inertial force due to the rotational action of the seal. It hits the fin, is pushed outward in the radial direction along the fin, and is discharged to the outside of the bearing. Therefore, when used in an environment where a large amount of water is applied, the water can be effectively discharged to the outside of the bearing.

Hereinafter, the best mode for carrying out the present invention will be described.
First, the configuration of an embodiment of the present invention will be described.
FIG. 1 shows a partial cross-sectional view of an idler pulley 40 using a rolling bearing 10 provided with a rolling bearing sealing device according to an embodiment of the present invention. FIG. 2 shows an enlarged view of the 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 double row ball bearing used for an idler pulley 40, and holds an inner ring 12, an outer ring 14, a double 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 30 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 30 form a sealing device that seals the rolling bearing 10.

  The seal 20 has an annular shape in which a core metal 22 is covered with a rubber seal, and a fixing portion 23 is formed on the outer periphery of the seal 20. The fixing portion 23 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 24 is formed on the inner periphery of the seal 20, and the seal lip 24 is in sliding contact with a sliding contact portion 13 provided on the outer diameter side of the inner ring 12. When the seal 20 rotates at a high speed together with the outer ring 14, the seal lip 24 rotates at a high speed while being in sliding contact with the sliding contact portion 13 of the inner ring 12. Therefore, the seal lip 24 is in light contact with the sliding contact portion 13.

As shown in FIG. 2, a conical axial lip 26 whose diameter increases toward the outside of the bearing is formed at the radial center portion of the side surface 25 facing the slinger 30 outside the bearing of the seal 20. The sliding surface 27 at the tip of the axial lip 26 is in contact with the flat portion 36 inside the bearing of the slinger 30. Here, the sliding surface 27 of the axial lip 26 and the flat portion 36 of the slinger 30 are in light contact to allow relative rotation of the seal 20 and the slinger 30. Further, eight triangular plate-like fins 28 are formed at equal intervals at the root portion of the axial lip 26 with respect to the side surface 25 of the seal 20 and spaced apart from the side surface 25 of the seal 20 in the circumferential direction. In addition, the space | interval and number of the fins 28 can be changed suitably.
FIG. 3 is a view taken along arrow A in FIG. As shown in FIG. 3, the fin 28 is formed to be inclined with respect to the radial direction, the root portion 28 a on the inner diameter side is the front in the rotation direction of the seal 20, and the tip portion 28 b on the outer diameter side is the seal 20. The direction of rotation is the rear.

  As shown in FIG. 2, the slinger 30 is an annular metal plate, and an inner peripheral end is bent in a cylindrical shape toward the inner side of the rolling bearing 10 to form a cylindrical portion 32. Is pressed into the outer diameter side of the inner ring 12, and the slinger 30 is fixed to the inner ring 12. And the front-end | tip part 34 of the outer periphery end of the slinger 30 has a clearance gap between the end surfaces of the collar 42 of the idler pulley 40, and forms the opening part 38 with respect to the exterior of a bearing. As described above, the sliding surface 27 of the axial lip 26 of the seal 20 is in contact with the flat portion 36 inside the bearing of the slinger 30 to close the gap between the seal 20 and the slinger 30.

Next, the function of the rolling bearing sealing device in one embodiment will be described.
In the rolling bearing 10, the sliding surface 27 at the distal end portion of the axial lip 26 formed on the side surface 25 facing the slinger 30 of the seal 20 contacts the flat portion 36 inside the bearing of the slinger 30, and the seal 20 and the slinger 30. The gap is closed. Therefore, foreign matter such as water and dust that has entered between the seal 20 and the slinger 30 from the opening 38 on the outer diameter side of the slinger 30 is prevented from entering the vicinity of the seal lip 26 on the inner diameter side of the bearing.
Here, the seal 20 is fixed to the outer ring 14 and rotates together with the outer ring 14. A plate-like fin 28 is formed at a root portion of the axial lip 26 on the side surface 25 of the seal 20 and spaced apart from the side surface 25 of the seal 20 in the circumferential direction. Therefore, the air between the seal 20 and the slinger 30 is sent outward in the radial direction by the rotational action of the fin 28 caused by the rotation of the seal 20. The foreign matter in the air is sent out radially outward by the inertial force due to the rotation, and is discharged to the outside of the bearing. Further, since air is sent radially outward, the air pressure between the radially outer seal 20 and the slinger 30 becomes higher than the outside air, and inside and outside the opening 38 formed at the tip 34 of the slinger 30. A pressure difference occurs. Therefore, intrusion of water, dust or the like between the seal 20 and the slinger 30 from the outside of the bearing is suppressed.

  However, in an environment where a large amount of water is applied to the rolling bearing 10, water may enter the gap between the seal 20 and the slinger 30 from the opening 38 on the outer diameter side of the slinger 30. In such a case, foreign matters such as water and dust that enter the gap between the seal 20 and the slinger 30 and accumulate in the groove between the side surface 25 of the seal 20 and the axial lip 26 rotate the seal 20 due to the inertial force due to the rotating action of the seal 20. It moves in the direction opposite to the direction and hits the fin 28. Here, since the fin 28 is formed so as to be inclined with respect to the radial direction such that the rear side in the rotational direction of the seal 20 is radially outward, the foreign matter has a diameter in the rear side in the rotational direction along the fin 28 due to inertial force. It is pushed out of the direction and discharged to the outside of the bearing. Therefore, when the rolling bearing 10 is used in an environment where a large amount of water is applied, the water can be effectively discharged to the outside of the bearing.

  As described above, in the sealing device for the rolling bearing 10, a pressure difference is generated between the inside and outside of the opening 38 of the slinger 20 to prevent foreign matter from entering between the seal 20 and the slinger 30. Then, foreign matter such as water and dust that has entered between the seal 20 and the slinger 30 is prevented from entering the vicinity of the seal lip 24, and foreign matter such as water and dust that has entered between the seal 20 and the slinger 30 is effectively removed. Can be discharged. Therefore, the sealing performance of the rolling bearing can be improved and the reliability can be further improved.

In the above-described embodiment, the axial lip 26 is formed at the central portion in the radial direction of the side surface 25 of the seal 20, but the formation position of the axial lip 26 is not limited to the central portion in the radial direction of the side surface 25 of the seal 20. Further, the shape of the axial lip 26 is not limited to a conical shape, and may be a shape in which the vicinity of the root to the side surface 25 is cylindrical and the diameter increases toward the tip.
In the above embodiment, the fins 28 are inclined with respect to the radial direction, but the direction of the fins 28 may be a radial direction that is straight with respect to the radial direction. If the fin 28 is in the radial direction, the negative angle portion is reduced, so that the seal 20 can be easily formed.
In the above embodiment, the tip 34 of the slinger 30 forms a gap with the flange 42 of the pulley 40. However, the outer ring 14 is substantially equal in width to the inner ring 12, and the tip 34 of the slinger 30 is the outer ring. It is good also as a structure which forms a clearance gap between 14 inner diameter surfaces.
In the above embodiment, 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 is sandwiched between the side surface of the inner ring 12 and a retaining ring fixed to the shaft. It is good also as a structure.

In the above embodiment, an example of an outer ring rotation type double row ball bearing used for an idler pulley is shown, but the application of the rolling bearing sealing device according to the present invention is not limited to an idler pulley. Further, the rolling bearing is not limited to a double row ball bearing. 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 one Example. It is an enlarged view of the part regarding the sealing device for rolling bearings in FIG. It is A arrow line view in FIG. It is a figure which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rolling bearing 12 Inner ring 13 Sliding contact part 14 Outer ring 15 Seal groove 16 Ball 18 Cage 20 Seal 22 Core 23 Fixing part 24 Seal lip 25 Side face 26 Axial lip 27 Sliding face 28 Fin 28a Root part 28b Tip part 30 Slinger 32 Cylindrical portion 34 Tip portion 36 Flat portion 38 Opening portion 40 Idler pulley 42 鍔

Claims (2)

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,
A conical axial lip that increases in diameter toward the outside of the bearing and contacts the slinger is formed on a side surface of the seal that faces the slinger, and a seal is provided at a base portion of the axial lip with respect to the side surface of the seal. A plurality of plate-shaped fins are formed spaced apart in the circumferential direction between the side surfaces of
The air between the seal and the slinger is sent outward in the radial direction by the rotational action of the fin caused by the rotation of the seal, and the pressure between the radially outer seal and the slinger is higher than the outside air, resulting in a pressure difference from the outside air. Thus, a foreign matter is prevented from entering between the seal and the slinger from the outside of the bearing. The rolling bearing sealing device according to claim 1,
The fins are formed to be inclined with respect to the radial direction, and the direction of the inclination of the fins is that the foreign matter that has entered between the side surface of the seal and the axial lip with respect to the rotation of the seal is radially outward of the bearing. A rolling bearing sealing device, characterized in that the direction is discharged to

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