JP4983353B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing that supports a rotating shaft that rotates at a high speed, for example.

  2. Description of the Related Art Conventionally, various devices such as a commutator motor of a power tool incorporate various rolling bearings that prevent foreign matters (eg, oil, grease, dust, etc.) from entering the bearing. As an example, FIG. 11 (a) proposes a bearing structure in which an oil seal 2 for preventing foreign matter intrusion is provided on the output shaft side of a commutator motor of a power tool (first prior art).

  In such a bearing structure, the two rotary shafts 4 and 6 are supported by the housing 12 via the rolling bearings 8 and 10, and the rotary motion of one rotary shaft 4 is transferred to the other rotary shaft 6 via the gear mechanism. It is to be transmitted. The gear mechanism is provided with a first gear 14 fixed to one rotating shaft 4 and a second gear 16 meshed with the first gear 14 and fixed to the other rotating shaft 6. It has been.

  In such a bearing structure, the rolling bearing 10 that supports the other rotating shaft 6 incorporates a sealing plate 18 between the inner and outer rings 10a and 10b, and the oil seal 2 described above is connected to the rolling bearing 10. Between the rotary shaft 6 and the housing 12. This prevents foreign matter (in particular, lubricant applied to the gear mechanism) from entering the bearing.

  Incidentally, in the first prior art (FIG. 11A), in addition to the sealing plate 18 incorporated between the inner and outer rings 10a and 10b, the oil seal 2 is further provided between the other rotary shaft 6 and the housing 12. Is incorporated. In this case, the number of parts constituting the bearing structure is increased, and it takes time and labor to assemble the bearing structure. Therefore, there is a problem that the manufacturing cost of the bearing is increased accordingly.

Therefore, for example, Patent Document 1 proposes a bearing structure in which an oil seal 24 is incorporated on one side between the inner and outer rings 20 and 22 and a sealing plate 26 is incorporated on the other side, as shown in FIG. (Second prior art). However, when the oil seal 24 is assembled between the inner and outer rings 20 and 22, depending on the use state of the bearing structure, the sealing performance of the entire bearing including the outer diameter side of the bearing (the outer diameter side of the outer ring 22) is the same as the conventional one. It may be difficult to maintain the level.
JP-A-8-184323

  The present invention has been made to solve such problems, and an object of the present invention is to provide a low-cost rolling bearing excellent in the sealing performance of the entire bearing including the outer diameter side of the bearing.

In order to achieve this object, the present invention comprises a bearing ring disposed so as to be relatively rotatable and an annular seal that seals the inside of the bearing defined between the bearing rings from the outside of the bearing. A rolling bearing having a base end portion fixed to one of the race rings and a tip end portion extending toward the other race ring, wherein the tip end portion of the seal is in contact with the peripheral surface of the other race ring. A groove that is positioned so as to be in slidable contact with each other and that is recessed in a concave shape along the circumferential direction on the circumferential surface opposite to the circumferential surface facing the other bearing ring. An annular O-ring is mounted in the concave groove, and the other raceway has a circumferential surface opposite to the circumferential surface facing one of the raceways, along its circumferential direction. A concave groove recessed in a concave shape is formed, and an annular O-ring is attached to the concave groove. The O-ring is set so that it partially protrudes from the groove when the O-ring is mounted, and the diameter of the O-ring is α, and the protruding amount when the O-ring is mounted in the groove is β Then, the relationship of (β / α) × 100 is set so as to be in the range of 20% to 50%.

In the present invention, the seal is configured by covering a core metal with a rubber material, and a protruding portion protruding toward the outside of the bearing is integrally formed with the rubber material at the base end portion of the seal. The protruding portion protrudes further to the bearing outer side than the bearing outer side end face of one of the bearing rings. In the present invention, the base end portion of the seal has a curled portion formed by partially bending the outer diameter side of the annular cored bar, and an elastic material coated so as to cover the curled portion. The base end is caulked and fixed to one of the race rings.

  Further, in the present invention, the peripheral surface of the other bearing ring in which the tip end portion of the seal is in sliding contact extends further to the bearing outer side than the bearing outer side end surface of the one bearing ring to which the base end portion of the seal is fixed. It is extended. In this case, the outer surface of the bearing ring may be chamfered on the peripheral surface of the other bearing ring in which the tip of the seal is in sliding contact.

  According to the present invention, it is possible to realize a low-cost rolling bearing excellent in sealing performance of the entire bearing including the bearing outer diameter side.

Hereinafter, a rolling bearing according to a first embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1 (a), the rolling bearing of the present embodiment is incorporated between a bearing ring (an inner ring 28, an outer ring 30) opposed to each other so as to be relatively rotatable, and inner and outer rings 28, 30 so as to roll freely. And a plurality of rolling elements 32 and annular seals 34 and 36 for sealing the inside of the bearing defined between the inner and outer rings 28 and 30 from the outside of the bearing. In the drawings, “balls” are illustrated as the rolling elements 32, but “rollers” may be applied. Further, the inner ring 28 is fixed by fitting the inner ring inner diameter surface 28s to the rotary shaft 38 and being rotatable, and the outer ring 30 is fixed by fitting the outer ring outer diameter surface 30s to the housing 40. It has come to be. Furthermore, in the drawings, the bearing structure is such that each rolling element 32 is held by the cage H, but the cage H is not necessarily required.

  The seals 34 and 36 are respectively provided on both sides of the inner and outer rings 28 and 30 with the plurality of rolling elements 32 interposed therebetween, and can prevent foreign matters such as oil, grease or dust from entering the bearing. It is configured as follows. Here, for example, various sealing plates such as a metal shield or a contact or non-contact type seal can be applied to the seal 34 on one side. A contact type seal 34 configured to cover the material 34b is applied. The contact-type seal 34 has a base end 34 e fixed to the fixing groove 30 g of the outer ring 30, a tip 34 t extending toward the inner ring 28, and an extending end (lip) 34 L of the sealing groove 28 g of the inner ring 28. Is positioned in sliding contact with the

  The seal 36 on the other side has a base end portion 36e fixed to the outer ring 30, a tip end portion 36t extending toward the inner ring 28, and extending ends (for example, an inner diameter lip L1 and a dust lip L2). The inner ring 28 is positioned so as to be in sliding contact with the peripheral surface (inner ring outer diameter surface) 28s. More specifically, the seal 36 is formed by covering an annular cored bar 36a with a rubber material 36b. The cored bar 36a extends from the base end part 36e toward the inside of the bearing, Bending toward 28 and extending.

  In this case, the base end portion 36e of the rubber material 36b is maintained in contact (pressure contact) with the inner periphery of the outer ring 30 when the base end portion 36e of the seal 36 is fixed to the outer ring 30, and the tip end portion 36t. The inner lip L1 and the dust lip L2 are integrally formed. The inner diameter lip L1 is positioned in a state in which it is pressed by the urging force of the ring-shaped spring member 42 and is in sliding contact with the inner ring outer diameter surface 28s, and the dust lip L2 protrudes from the inner diameter lip L1 on the inner side of the bearing. Thus, it is in sliding contact with the inner ring outer diameter surface 28s. The dust lip L2 is not always necessary.

  According to such a configuration, it is not necessary to separately assemble the oil seal 2 (corresponding to the seal 36 of the present embodiment) and the rolling bearing as in the prior art (FIG. 11A), and the seal 36 is previously attached to the outer ring 30. Can be incorporated. Thereby, the assembly of the seal 36 can be completed at the same time only by fixing the outer ring 30 to the housing 40. In this case, it takes less time to assemble the rolling bearing than in the prior art. For this reason, the manufacturing cost of a bearing can be reduced significantly compared with the past.

  Further, in the seal 36 shown in FIG. 1A, the base end portion 36e is provided with a protruding portion 36p protruding toward the bearing outer side, and the protruding portion 36p is a bearing of the outer ring 30. A predetermined amount δ protrudes further to the bearing outer side than the outer side end face 30a. In this case, the protrusion amount δ of the protrusion 36p is arbitrarily set according to, for example, the purpose and environment of use of the rolling bearing or the shape and size of the outer ring 30, and is not specifically limited here. The protruding portion 36p may be integrally formed with the rubber material 36b covered by the base end portion 36e, or may be formed separately and retrofitted by a method such as adhesion, welding, or fusion. good.

  According to such a configuration, when the outer ring 30 is fitted and fixed to the housing 40 so that the base end portion 36e of the seal 36 is applied to the stepped surface 40m of the housing 40, the protruding portion 36p corresponds to the protruding amount δ. Crimp on the stepped surface 40m without any gaps. In this case, the entire region from the bearing outer side end surface 30a of the outer ring 30 to the fitting portion between the outer ring outer diameter surface 30s and the housing 40 is maintained in a state of being completely sealed (isolated) from the outside of the bearing by the seal 36. . Thereby, for example, a foreign matter such as oil or grease leaks from the outer end surface 30a of the bearing to the opposite side (the opposite end surface 30b of the outer ring 30) through the outer ring outer diameter surface 30s and the housing 40. It can be avoided.

  Further, in the above-described seal 36, for example, one or a plurality of O-rings 44 are interposed between the inner ring inner surface 28 s and the rotary shaft 38, between the outer ring outer surface 30 s and the housing 40, or between both. You may make it let it. As an example, the drawing shows a configuration in which two O-rings 44 are interposed between the outer ring outer diameter surface 30 s and the housing 40 and between the inner ring inner diameter surface 28 s and the rotating shaft 38. In this case, each O-ring 44 is mounted in a concave groove G in which a part of the outer ring outer diameter surface 30s and the inner ring inner diameter surface 28s are recessed in the circumferential direction.

  Here, regarding the configuration (for example, shape, size, etc.) of the O-ring 44 and the concave groove G, the O-ring 44 partially protrudes from the concave groove G with the O-ring 44 attached to the concave groove G. It is preferable to set to. Specifically, as shown in FIG. 1 (b), when the diameter of the O-ring 44 is α and the protrusion amount when the O-ring 44 is mounted in the groove G is β, (β / α) × It is preferable to set so that the relationship of 100 falls within the range of 20% to 50%. This is because when the inner ring 28 is fitted to the rotating shaft 38 (the outer ring 30 is the housing 40), the O-ring 44 is between the inner ring inner surface 28s and the rotating shaft 38 and between the outer ring outer surface 30s and the housing 40. It is defined as “smashing”.

  According to such a configuration, when the inner ring 28 is fitted and fixed to the rotary shaft 38 (the outer ring 30 is fitted to the housing 40), the O-ring 44 that partially protrudes from the concave groove G corresponds to the rotary shaft 38 ( Crimp the housing 40) without any gaps. Thereby, the sealing performance between the outer ring outer diameter surface 30s and the housing 40 and the sealing performance between the inner ring inner diameter surface 28s and the rotary shaft 38 can be improved. As a result, it is possible to reliably prevent foreign matters such as oil and grease from leaking to the opposite side through between the inner ring inner surface 28s and the rotary shaft 38 and between the outer ring outer surface 30s and the housing 40. .

  Furthermore, by setting the crushing margin ((β / α) × 100) within a range of 20% to 50%, the inner ring 28 and the rotary shaft 38 (the outer ring 30 and the housing 40) are optimally connected via the O-ring 44. It can be fitted (fixed) with a sufficient frictional force. As a result, it is possible to reliably prevent the occurrence of a relative slip phenomenon (creep) between the inner ring 28 and the rotating shaft 38 (the outer ring 30 and the housing 40) during rotation of the bearing.

  In the above-described embodiment, the material of the rubber material 36b of the seal 36 is not particularly mentioned. Examples of the material include nitrile rubber, acrylic rubber having a Shore hardness (A) of about 60 to 85, It is preferable to apply fluororubber or the like. The material is arbitrarily set according to, for example, the purpose and environment of use of the rolling bearing (peripheral speed and temperature of the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36). There is no particular limitation.

  Further, the Rockwell hardness (HRC) of the inner ring 28 with which the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36 is in sliding contact is set to 55 or more, and the surface roughness (Ra) of the outer diameter surface 28s of the inner ring is 0. It is preferable to grind to about 0.1 to 0.32 μm. Here, for example, if the material of the tip portion 36t (rubber material 36b) exceeds nitrile rubber with a peripheral speed of 16 m / s, acrylic rubber with a peripheral speed of 25 m / s, and fluororubber with a peripheral speed of 32 m / s, the tip portion 36t (inner diameter) The lip L1 and the dust lip L2) and the inner ring outer diameter surface 28s wear and generate heat, and as a result, the sealing performance may deteriorate. In this case, for example, if the hardness index of the rubber material 36b is A70, it is preferable that the hardness of the inner ring 28 with which the front end portion 36t of the seal 36 is in sliding contact is HRC73 or more. Further, for example, the sliding characteristics may be improved by applying a hard surface treatment to the inner ring outer diameter surface 28s to finish the inner surface with a predetermined surface roughness.

The present invention is not limited to the first embodiment described above, and the following modifications are also included in the scope of the present invention.
As a first modified example, as shown in FIG. 2, the above-described seals 36 may be provided on both sides of the bearings (inner and outer rings 28, 30) so as to be reversed left and right. In this case, the inner lip L1 of each seal 36 (tip portion 36t) is positioned so as to face the outside of the bearing. According to such a configuration, foreign matters (for example, oil and grease) existing outside the bearing can be reliably prevented from entering the inside of the bearing from both sides of the bearing (inner and outer rings 28 and 30). Since other configurations and effects are the same as those of the first embodiment described above, description thereof is omitted.

  As a second modification, as shown in FIG. 3, the above-described seals 36 may be provided on both sides of the bearing (inner and outer rings 28, 30) in the same direction. In this case, the inner lip L1 of each seal 36 (tip portion 36t) is positioned so as to face the bearing external direction (for example, the left side in the figure). According to such a configuration, foreign matter (e.g., oil, grease) existing outside the bearing permeates into the bearing from one side (the left side in the figure) of the bearing (inner and outer rings 28, 30), and the opposite side (in the figure). A situation such as leakage to the right side) can be reliably avoided. Since other configurations and effects are the same as those of the first embodiment described above, description thereof is omitted.

  As a third modified example, as shown in FIG. 4, the inner ring outer diameter surface 28 s of the inner ring 28 slidably in contact with the tip 36 t (inner diameter lip L 1, dust lip L 2) of the seal 36 described above is used as the base end of the seal 36. The outer ring 30 on which the outer ring 30 to which the bearing 36e is fixed may extend further to the bearing outer side than the end surface 30a. In other words, the width dimension between the bearing outer end face 30a and the opposite end face 30b of the outer ring 30 is W1, and the width dimension between the bearing outer end face 28a and the opposite end face 28b of the inner ring 28 is set as W1. When the opposite end face 30b of the outer ring 30 and the opposite end face 28b of the inner ring 28 are set at the same position as W2, the width dimension W2 of the inner ring 28 is larger than the width dimension W1 of the outer ring 30 toward the outside of the bearing. ing. In this case, the bearing outer side end surface 28 a of the inner ring 28 is positioned closer to the bearing outer side than the bearing outer side end surface 30 a of the outer ring 30.

  According to such a configuration, it is possible to ensure a large area where the tip portion 36t (inner diameter lip L1, dust lip L2) of the seal 36 is in sliding contact with the inner ring outer diameter surface 28s. In this case, the sealing performance (the blocking effect of the seal 36) between the tip portion 36t and the inner ring outer diameter surface 28s can be dramatically improved. Thereby, for example, foreign matters such as oil, grease or dust can be reliably prevented from entering the inside of the bearing through the space between the tip portion 36t and the inner ring outer diameter surface 28s. As a result, the rotational performance and lubrication performance of the rolling bearing can be maintained constant over a long period of time. Since other configurations and effects are the same as those of the first embodiment described above, description thereof is omitted.

  Further, in the rolling bearing shown in FIG. 4, the inner ring outer diameter surface 28s slidably contacted with the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36 is chamfered 28m on the outer side of the bearing. Yes. In this case, the width (width) and the inclination angle of the chamfer 28m are arbitrarily set according to, for example, the size and shape of the tip 36t of the seal 36 and the inner ring 28, and are not particularly limited here.

  According to such a configuration, it is possible to improve the insertability when the seal 36 is inserted between the inner and outer rings 28 and 30 and incorporated. More specifically, the seal 36 has a large and complicated configuration of the tip portion 36t in order to set the sealing performance relatively high from the purpose of use. For this reason, when the seal 36 is inserted between the inner and outer rings 28 and 30, the tip portion 36t of the seal 36 is hooked or brought into contact with the inner ring 28, for example, so that the seal 36 is smoothly connected between the inner and outer rings 28 and 30. It may be difficult to insert into the.

  On the other hand, when the seal 36 is inserted between the inner and outer rings 28, 30 by chamfering 28m on the bearing outer side (the insertion side of the seal 36) of the inner ring outer diameter surface 28s, the tip 36t is chamfered. Since it is guided along 28 m, the tip end portion 36 t does not catch or come into contact with the inner ring 28, for example. Accordingly, the seal 36 can be smoothly inserted between the inner and outer rings 28 and 30 with a simple insertion jig.

  As a fourth modified example, as shown in FIG. 5, a new sealing plate may be further provided in the region between the seal 36 and the rolling element 32. Here, as the sealing plate, various types such as a metal shield and a contact or non-contact type seal can be applied. However, in the drawing, as an example, a contact type seal having the same configuration as the seal 34 is used. A board is applied. In this case, the base 34e of the new sealing plate 34 is fixed to the fixing groove 30g of the outer ring 30, the tip 34t extends toward the inner ring 28, and its extended end (lip) 34L is the seal groove of the inner ring 28. It is positioned in sliding contact with 28g.

  According to this configuration, it is possible to prevent wear powder or the like generated inside the bearing from reaching the seal 36. Here, when wear powder or the like reaches the seal 36 and enters, for example, between the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36 and the inner ring outer diameter surface 28s, the tip of the seal 36 is caused by the wear powder. The portion 36t and the inner ring outer diameter surface 28s may be damaged or worn. In this case, it may be difficult to maintain the sealing performance (the blocking effect of the seal 36) between the tip portion 36t and the outer diameter surface 28s of the inner ring constant over a long period of time.

  However, by providing a new sealing plate 34 between the seal 36 and the rolling element 32, it is possible to prevent wear powder generated inside the bearing from reaching the seal 36. As a result, the sealing performance between the tip portion 36t and the inner ring outer diameter surface 28s (blocking effect of the seal 36) can be maintained constant over a long period of time. Since other configurations and effects are the same as those of the first embodiment described above, description thereof is omitted.

  Further, in the rolling bearing shown in FIG. 5, the chamfer 28m similar to that of the third modification described above is formed on the inner ring outer diameter surface 28s slidably in contact with the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36. May be applied. According to such a configuration, it is possible to improve the insertability when the seal 36 is inserted between the inner and outer rings 28 and 30 and incorporated.

  As shown in FIG. 6 as a fifth modification, the direction of the seal 36 of the third modification (FIG. 4) may be reversed left and right. In this case, in the seal 36, the cored bar 36a extends from the base end portion 36e toward the outside of the bearing, and then bends and extends toward the inner ring 28. The inner diameter lip L1 of the tip end portion 36t has a bearing It is positioned in a state in which it faces the outer direction (for example, the left side in the figure) and is in sliding contact with the inner ring outer diameter surface 28s. According to such a configuration, the space volume inside the bearing can be increased, and therefore the amount of lubricant enclosed can be increased. As a result, it is possible to extend the life of the bearing. Other configurations and effects are the same as those of the above-described third modified example (FIG. 4) and the first embodiment, and thus description thereof is omitted.

  As shown in FIG. 7 as a sixth modified example, the seal 36 of the fifth modified example (FIG. 6) is provided on both sides of the bearing (inner and outer rings 28, 30) so as to be reversed left and right, and the inner ring outer diameter of the inner ring 28 is provided. The surface 28s may extend beyond the bearing outer side end surface 30a and the opposite side end surface 30b of the outer ring 30. According to such a configuration, the space volume inside the bearing can be further increased as compared with the fifth modified example (FIG. 6), so that the amount of lubricant enclosed can be further increased. As a result, it is possible to extend the life of the bearing. Since other configurations and effects are the same as those of the above-described fifth modification (FIG. 6) and the first embodiment, the description thereof is omitted.

Next, a rolling bearing according to a second embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 8, in the rolling bearing of the present embodiment, a curled portion 36k formed by bending a part of the outer diameter side of an annular cored bar 36a at the base end portion 36e of the seal 36; An elastic material covered so as to cover the curled portion 36k is interposed. As the elastic material, the rubber material 36b applied to the seal 36 of the first embodiment described above may be used, or another material (for example, a resin material) may be used. Here, the rubber material 36b is used as an elastic material as an example.

  The base end portion 36e of such a seal 36 is fixed by caulking a curled portion 36k covered with a rubber material 36b to the outer ring 30. Further, the cored bar 36a extends from the base end part 36e (curled part 36k) so as to incline toward the bearing, and then extends toward the inner ring 28. In this case, a rubber material 36b is covered at the front end portion 36t of the seal 36 so as to cover the extending end of the core metal 36a, and the rubber material 36b includes the seal 36 of the first embodiment described above. Similarly, the inner lip L1 and the dust lip L2 are integrally formed. Since the other configuration is the same as that of the first embodiment (FIGS. 1A and 1B), the same configuration is the same as that of the embodiment (FIG. 8). Are denoted by the same reference numerals, and the description thereof is omitted.

  As described above, according to the present embodiment, the base end portion 36e of the seal 36 is fixed by caulking to the outer ring 30, so that the seal 36 can be firmly fixed to the outer ring 30 in a stable posture without wobbling. it can. In this case, the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36 can always be brought into sliding contact with the inner ring outer diameter surface 28s with an optimum pressure. Thereby, the sealing performance of the front-end | tip part 36t of the seal | sticker 36 and the inner ring | wheel outer diameter surface 28s can be maintained constant.

  Furthermore, according to the present embodiment, there is no need to separately assemble the oil seal 2 (corresponding to the seal 36 of the present embodiment) and the rolling bearing as in the prior art (FIG. 11A), and the seal 36 It can be incorporated in the outer ring 30 in advance. Thereby, the assembly of the seal 36 can be completed at the same time only by fixing the outer ring 30 to the housing 40. In this case, it takes less time to assemble the rolling bearing than in the prior art. For this reason, the manufacturing cost of a bearing can be reduced significantly compared with the past. Since other effects are the same as those of the first embodiment (FIGS. 1A and 1B) described above, description thereof is omitted here.

The present invention is not limited to the second embodiment described above, and the following modifications are also included in the scope of the present invention.
As a first modified example, as shown in FIG. 9, the cored bar 36 a of the seal 36 extends from the base end part 36 e (curled part 36 k) so as to be inclined toward the outside of the bearing, and then extends toward the inner ring 28. ing. In this case, an inner diameter lip L1 and a dust lip L2 formed integrally with the rubber material 36b are provided at the tip 36t of the seal 36. The inner ring outer diameter surface 28s of the inner ring 28 slidably in contact with the distal end portion 36t (inner diameter lip L1, dust lip L2) of the seal 36 is a bearing outer side end surface 30a of the outer ring 30 to which the base end portion 36e of the seal 36 is fixed. It extends further to the outside of the bearing.

  According to such a configuration, the space volume inside the bearing can be increased, and therefore the amount of lubricant enclosed can be increased. As a result, it is possible to extend the life of the bearing. Further, by extending the inner ring outer diameter surface 28s so as to extend further to the bearing outer side than the bearing outer side end face 30a, it is possible to ensure a large region where the tip portion 36t of the seal 36 is in sliding contact with the inner ring outer diameter surface 28s. Can do. Thereby, the sealing performance (the blocking effect of the seal 36) between the tip portion 36t and the inner ring outer diameter surface 28s can be improved.

  Further, in the rolling bearing shown in FIG. 9, the inner ring outer diameter surface 28s slidably in contact with the tip 36t (inner diameter lip L1, dust lip L2) of the seal 36 is the third embodiment of the first embodiment described above. A chamfer 28m similar to that of the modified example (FIG. 4) may be applied. According to such a configuration, it is possible to improve the insertability when the seal 36 is inserted between the inner and outer rings 28 and 30 and incorporated. Since other configurations and effects are the same as those of the second embodiment described above, description thereof is omitted.

  As a second modification, a new sealing plate may be further provided in the region between the seal 36 and the rolling element 32 as shown in FIG. Here, as the sealing plate, for example, various types such as a metal shield and a contact or non-contact type seal can be applied. In the drawing, as an example, the first embodiment in the first embodiment described above is used. A contact-type sealing plate having the same configuration as the seal 34 of the fourth modification (FIG. 5) is applied.

  According to this configuration, it is possible to prevent wear powder or the like generated inside the bearing from reaching the seal 36. As a result, the sealing performance between the tip portion 36t and the inner ring outer diameter surface 28s (blocking effect of the seal 36) can be maintained constant over a long period of time. Other configurations and effects are the same as those of the second embodiment and the fourth modified example (FIG. 5) described above, and thus description thereof is omitted.

  Although not specifically illustrated, for example, the second embodiment is similar to the arrangement of the seal 34 according to the first and second modifications (FIGS. 2 and 3) in the first embodiment described above. Seals 34 according to the embodiment (FIG. 8) may be provided on both sides of the bearing (inner and outer rings 28, 30). According to this configuration, it is possible to achieve the same effects as those of the first and second modifications (FIGS. 2 and 3).

(a) is sectional drawing which shows the structure of the rolling bearing which concerns on the 1st Embodiment of this invention, (b) is typical about the relationship between the diameter of O-ring in the state mounted to the ditch | groove, and protrusion amount. FIG. Sectional drawing which shows the structure of the rolling bearing which concerns on the 1st modification in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 2nd modification in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 3rd modification in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 4th modification in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 5th modification in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 6th modification in the 1st Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 1st modification in the 2nd Embodiment of this invention. Sectional drawing which shows the structure of the rolling bearing which concerns on the 2nd modification of the 2nd Embodiment of this invention. (a) is sectional drawing which shows the bearing structure which concerns on 1st prior art, (b) is sectional drawing which shows the bearing structure which concerns on 2nd prior art.

Explanation of symbols

28 Inner ring 28s peripheral surface (inner ring outer diameter surface)
30 Outer ring 36 Seal 36e Base end 36t Tip

Claims (5)

The bearing ring includes a bearing ring that is disposed so as to be relatively rotatable and an annular seal that seals the inside of the bearing defined between the bearing rings from the outside of the bearing, and the base end of the seal is fixed to one of the bearing rings. A rolling bearing whose tip extends toward the other race ring,
The tip of the seal is positioned in a state of sliding contact with the peripheral surface of the other raceway ring ,
One raceway is formed with a concave groove recessed in the circumferential direction on the circumferential surface opposite to the circumferential surface facing the other raceway, and the concave groove has an annular shape. O-ring is installed,
The other raceway is formed with a concave groove that is recessed in the circumferential direction on the circumferential surface opposite to the circumferential surface facing one of the raceways. O-ring is installed,
The O-ring is set so that it partially protrudes from the groove when the O-ring is attached to the groove, and the diameter of the O-ring is α, and the amount of protrusion when the O-ring is attached to the groove is A rolling bearing characterized in that, when β, the relationship of (β / α) × 100 is set to be in a range of 20% to 50% . The seal is configured by covering a core metal with a rubber material, and a protruding portion protruding toward the outside of the bearing is integrally formed with the rubber material at the base end portion of the seal. The rolling bearing according to claim 1, wherein the bearing protrudes further toward the bearing outer side than the bearing outer side end face of one of the race rings.   The base end portion of the seal includes a curled portion formed by partially bending the outer diameter side of the annular cored bar, and an elastic material covered so as to cover the curled portion, The rolling bearing according to claim 1, wherein the base end portion is fixed by caulking to one of the race rings. The peripheral surface of the other bearing ring in which the tip of the seal is in sliding contact extends further to the bearing outer side than the bearing outer side end surface of the one bearing ring to which the base end of the seal is fixed. The rolling bearing according to any one of claims 1 to 3 . The rolling bearing according to any one of claims 1 to 4 , wherein the bearing ring is chamfered on the outer peripheral surface of the other bearing ring in which the tip of the seal is in sliding contact.

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