JP2009192056A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the lubrication performance of a rolling bearing, and to prevent the leakage of oil. <P>SOLUTION: A grease sump 60 is made to communicate with a contact part P of an outer ring 10 and a rolling body 30 via a microflow passage 62. By this, the lubrication performance of the bearing can be enhanced by feeding an oil component of grease to the contact part P by a capillary force of the microflow passage 62. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing such as a cylindrical roller bearing, a tapered roller bearing, or a ball bearing.

  For example, as shown in FIG. 5, the cylindrical roller bearing disclosed in Patent Document 1 includes an outer ring 210, an inner ring 220, and a plurality of cylindrical rollers 230 disposed therebetween, and a grease pocket 242. The recessed end surface member 240 is disposed adjacent to both end surfaces of the bearing. By supplying the oil contained in the grease in the grease pocket 242 into the bearing, the bearing is lubricated.

  Since a small amount of oil is supplied from the grease in the grease pocket 242 into the bearing, in this cylindrical roller bearing, the inner diameter surface of the flange portion 212 of the outer ring 210 and the inner peripheral surface of the grease pocket 242 of the end surface member 240 are flush with each other. This makes it easy to supply grease oil into the bearing.

JP 2000-291667 A

  However, when the oil content of the grease is low or when it becomes difficult to separate the oil from the grease by using it in a low temperature environment, supply sufficient oil to the bearing even with the above configuration. It cannot be said that further improvements are required.

  Further, in the above bearing, since the grease pocket 242 is an open space and a gap is formed between the end face member 240 and the inner ring 220, the grease held in the grease pocket 242 from this gap Oil may leak out.

  An object of the present invention is to improve the lubricity of a rolling bearing and prevent oil leakage.

  In order to achieve the above-described object, the present invention provides an outer ring, an inner ring, a plurality of rolling elements that are movably interposed between both race rings, and a lubricant that holds a lubricant supplied to the inside of the bearing. A rolling bearing provided with a reservoir is characterized in that a lubricant reservoir and a contact portion between one race and a rolling element are communicated with each other through a micro flow path.

  As described above, the lubricant reservoir is communicated with the contact portion between the one raceway ring and the rolling element via the micro flow path, so that the lubricant is caused by the capillary force of the micro flow path between the outer ring or the inner ring and the rolling element. The contact portion can be supplied. Therefore, even when the amount of lubricant held in the lubricant reservoir is extremely small, the lubricant can be reliably supplied to the sliding portion in the bearing, so that the lubricity can be improved. In addition, since the lubricant reservoir can be made a closed space by communicating the lubricant reservoir and the inside of the bearing via a micro flow path, leakage of the lubricant from the lubricant reservoir can be avoided. (See FIG. 2).

  Such a lubricant reservoir can be formed by, for example, a lubricant holding member fixed to one of the race rings. In this case, the outer peripheral surface of the lubricant holding member and the inner peripheral surface of one of the race rings are brought into contact with each other, and a groove is provided on at least one of these surfaces, and the minute flow path can be formed by the groove.

  For example, in the main motor of a railway vehicle, the current of the main motor may flow to the wheels and rails through the rolling bearing. When a current flows in the bearing in this way, a spark is generated between the rolling elements of the bearing and the bearing ring, which may shorten the bearing life. In order to avoid such a situation, there has been proposed one in which the surface of the outer ring attached to the housing is covered with an insulating layer made of resin (see, for example, Japanese Patent Application Laid-Open No. 2007-170673). When the lubricant holding member is provided as described above, it is preferable to apply a resin coating to the mounting surface of the lubricant holding member to the housing, since current may flow through the lubricant holding member. Alternatively, the lubricant holding member itself may be formed of resin.

  Thus, the following effects can be obtained by applying a resin coating to the lubricant holding member or by forming the lubricant holding member with a resin. That is, during the operation of the bearing or the operation of a device equipped with the bearing (for example, a main motor), the temperature of the lubricant held in the lubricant reservoir rises due to these heat generation, and the viscosity decreases and the inside of the bearing decreases. It becomes easy to be supplied to. In particular, when the lubricant is grease, the oil component is easily separated from the grease due to temperature rise, and the amount of oil supplied increases. At this time, if the lubricant holding member is coated with resin as described above or the lubricant holding member is formed of resin, the heat retention performance of the lubricant reservoir is improved and the temperature of the lubricant is maintained at a relatively high temperature. Therefore, it is possible to maintain a state in which the lubricant is easily supplied into the bearing.

  The rolling bearing as described above can be suitably used, for example, for supporting a rotating shaft of a main motor of a railway vehicle.

  As described above, according to the present invention, it is possible to improve the lubricity of the rolling bearing and prevent oil leakage.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a rolling bearing 1 according to an embodiment of the present invention. The bearing 1 is a cylindrical roller bearing used for supporting a rotating shaft of a main motor of a railway vehicle. A plurality of rolling elements arranged between the outer ring 10, the inner ring 20, and the outer ring 10 and the inner ring 20. The cylindrical roller 30, a cage 40 that holds the plurality of cylindrical rollers 30 at equal intervals in the circumferential direction, and a grease holding member 50 as a lubricant holding member.

  The outer ring 10 has a raceway surface 12 on the inner peripheral surface, and includes collar portions 14 on both sides in the axial direction of the raceway surface 12. The outer ring 10 is press-fitted into the housing 2, and a resin coating layer 16 is formed on the mounting surface of the outer ring 10 on the housing 2, that is, on the outer peripheral surface and both end surfaces in the axial direction. In addition, stepped portions 18 for centering the grease holding member 50 are provided at inner diameter ends of both end faces of the outer ring 10. The inner ring 20 has a raceway surface 22 on the outer peripheral surface, and is fitted and fixed to the outer peripheral surface of a rotating shaft (not shown).

  The grease holding member 50 is attached to both ends in the axial direction of the inner peripheral surface of the outer ring 10, and forms a grease reservoir 60 filled with grease inside (the dotted points in FIG. 2 represent the grease). Specifically, as shown in FIG. 2, a ring portion 52 provided so as to surround the grease reservoir 60 and a tip portion 54 extending in the axial direction from the ring portion 52 are provided.

  The ring portion 52 includes a large-diameter cylindrical portion 52a that extends axially from the end face of the outer ring 10 to the bearing outer side (right side in FIG. 2), and an outer portion that extends from the end of the large-diameter cylindrical portion 52a on the bearing outer side to the inner diameter. An end surface portion 52b, a small diameter cylindrical portion 52c extending axially from the inner diameter end of the outer end surface portion 52b to the bearing inner side (left side in FIG. 2), and extending from the end of the small diameter cylindrical portion 52c on the bearing inner side to the outer diameter. The inner end surface portion 52d and the tapered portion 52e extending while gradually reducing the diameter from the outer diameter end of the inner end surface portion 52d toward the bearing inner side. Of the ring portion 52, a resin coating layer 56 is provided on the outer peripheral surface (the outer peripheral surface of the large-diameter cylindrical portion 52 a) serving as a mounting surface to the housing 2 and the bearing outer side end surface (the outer side end surface of the outer end surface portion 52 b). For example, the resin coating layer 56 is formed separately from the base material of the ring portion 52 and then fixed to the base material by means such as adhesion. In this state, the grease retaining member 50 is fixed to the housing 2 by being press-fitted into the inner peripheral surface of the housing 2. At this time, the resin coating layer 56 is sandwiched between the base material of the ring portion 52 and the housing 2 and is slightly crushed. An end portion of the ring portion 52 (end portion on the bearing inner side of the large-diameter cylindrical portion 52a) is fitted to the step portion 18 of the outer ring 10, whereby the outer ring 10 and the grease holding member 50 are centered.

  The outer peripheral surface of the distal end portion 54 of the grease holding member 50 is in contact with the inner peripheral surface of the collar portion 14 of the outer ring 10. A plurality of axial grooves 58 are formed on the outer peripheral surface of the distal end portion 54 at equal intervals in the circumferential direction. An axial micro flow path is formed between the groove 58 and the inner peripheral surface of the collar portion 14 of the outer ring 10. 62 is formed. The minute flow path communicates the grease reservoir 60 with the contact portion (indicated by P in FIG. 2) between the collar portion 14 of the outer ring 10 and the cylindrical roller 30. The groove 58 is not limited to the axial direction as long as the grease reservoir 60 and the contact portion P communicate with each other, and may be formed, for example, inclined in the circumferential direction or formed in a knurled shape.

  When the bearing 1 rotates, the oil component is separated from the grease in the grease reservoir 60 due to the heat generation of the bearing 1 itself or the heat generation of the main motor, and the oil component is drawn by the capillary force of the microchannel 62 and supplied to the contact portion P. Thus, the bearing 1 is lubricated. As described above, since the grease reservoir 60 and the contact portion P are communicated with each other through the micro flow channel 62, oil can be supplied into the bearing by using the capillary force of the micro flow channel 62, so that more abundant oil can be supplied. Can be supplied. Further, by supplying oil through the micro flow path 62, the grease reservoir 60 can be made into a closed space surrounded by the ring portion 52, so that leakage of grease to the outside can be avoided.

  Further, by providing the resin coating layers 16 and 56 on the mounting surfaces of the outer ring 10 and the grease retaining member 50 to the housing 2, it is possible to prevent a current from flowing inside the bearing 1 and avoid a decrease in bearing life due to energization. it can. Further, by providing the resin holding layer 56 on the grease holding member 50, the heat retaining property of the grease reservoir 60 can be enhanced and the supply of oil from the grease can be promoted.

  In such a bearing 1, if the radial dimension of the ring portion 52 of the grease holding member 50 is increased, the volume of the internal grease reservoir 60 is also increased, so that more grease can be held. Further, if the ring portion 52 is extended to the inner diameter side, a gap (indicated by L in FIG. 1) between the ring portion 52 and the inner ring 20 can be reduced, so that oil leaks from the inside of the bearing to the outside. Intrusion of foreign matter from the outside into the bearing can be prevented. Therefore, it is preferable that the ring portion 52 is set to the inner diameter side as much as possible, that is, to make the gap L as small as possible within a range that does not interfere with the inner ring 20 and other members.

  The present invention is not limited to the above embodiment. FIG. 3 shows a bearing according to another embodiment of the present invention. The bearing 100 includes an outer ring 110, an inner ring 120, a tapered roller 130 interposed between the outer ring and the inner ring, a cage 140 that holds the plurality of tapered rollers 130 at equal intervals in the circumferential direction, and a grease holding member. 150 and a sealing device 170. The seal device 170 includes a seal washer 172 fixed to the inner peripheral surface of the outer ring 110 and a seal member 174 disposed on the inner periphery of the seal washer 172 to prevent oil leakage from the inside of the bearing. .

  The grease holding member 150 is made of, for example, resin and is fixed to the inner periphery of the seal washer 172. Specifically, a bent portion 152 having a substantially U-shaped cross section and forming a grease reservoir 160 between the seal washer 172 and a tip portion 154 extending in the axial direction from the bent portion 152 is provided. The end surface of the bent portion 152 is fixed to the seal washer 172 by adhesion or the like, and thereby the grease holding member 150 is attached to the outer ring 110 via the seal washer 172. Grooves 156 in the axial direction (strictly in the direction of the raceway surface of the outer ring 110) are formed on the outer peripheral surface of the distal end portion at a plurality of locations at equal intervals in the circumferential direction. A minute flow path 162 is formed by the groove 156 and the inner peripheral surface of the outer ring 110, and the minute flow path 162 communicates between the grease reservoir 160 and the contact portion P between the outer ring 110 and the tapered roller 130.

  In the present embodiment, since the grease holding member 150 is fixed to the seal washer 172 by adhesion, a large force is not applied unlike the press-fitting and the grease holding member 150 can be formed of resin. As described above, by forming the entire grease holding member 150 with resin, it is possible to obtain effects such as insulation and heat retention without providing a resin coating layer as in the above embodiment.

  In the above embodiment, the case where the minute flow path is configured by the groove formed in the tip portion of the grease holding member has been described, but the present invention is not limited thereto. For example, it is possible to form a micro flow path by forming a groove on the outer ring side or by forming a groove on both the outer ring side and the grease holding member side. In addition, the outer peripheral surface of the tip and the inner peripheral surface of the outer ring are both formed into a cylindrical surface (tapered surface), and these surfaces are brought into a non-contact state through a minute gap, thereby forming a micro flow path. You can also Alternatively, a minute convex portion is formed on one or both of the contact surfaces of the outer ring and the grease holding member, and a minute gap is formed by contacting the surface facing this convex portion. Thus, a minute channel can be formed.

  In the above embodiment, since the inner ring is mounted on the rotating shaft, the case where the lubricant holding member is attached to the fixed outer ring side is shown. For example, when the outer ring side is the rotating side, the inner ring side It is good also as a structure which attaches a lubricant holding member. If there is no problem such as fixing force, a lubricant holding member may be attached to the rotating side.

  Moreover, although the case where grease was used as the lubricant was shown in the above embodiment, the present invention is not limited to this, and other lubricants such as oil can also be used.

  Moreover, although the case where this invention was applied to a cylindrical roller bearing and a tapered roller bearing was shown in the above embodiment, it can apply not only to this but other rolling bearings, such as a ball bearing. Furthermore, the rolling bearing of the present invention can be applied not only to railway vehicles but also to other uses such as automobiles and industrial equipment.

It is sectional drawing of the cylindrical roller bearing which concerns on this invention. It is sectional drawing which expands and shows a lubricant holding member. It is sectional drawing of the tapered roller bearing which concerns on this invention. It is sectional drawing which expands and shows a lubricant holding member. It is sectional drawing of the conventional rolling bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing 2 Housing 10 Outer ring 20 Inner ring 30 Rolling element 40 Cage 50 Grease holding member (lubricant holding member)
52 Ring portion 54 Tip portion 56 Resin coating layer 58 Axial groove 60 Grease reservoir (lubricant reservoir)
62 Microchannel P Contact part

Claims (6)

In a rolling bearing comprising an outer ring, an inner ring, a plurality of rolling elements movably interposed between both race rings, and a lubricant reservoir for holding a lubricant supplied into the bearing,
A rolling bearing characterized in that a lubricant reservoir and a contact portion between one race ring and a rolling element are communicated with each other through a micro flow path.   The rolling bearing according to claim 1, wherein a lubricant holding member is attached to one of the race rings, and the lubricant reservoir is formed by the lubricant holding member.   3. A rolling bearing according to claim 2, wherein the outer peripheral surface of the lubricant holding member and the inner peripheral surface of one of the race rings are brought into contact with each other, and a groove is formed in at least one of these surfaces, and the minute flow path is formed by the groove. .   The rolling bearing according to claim 2, wherein a resin coating layer is formed on the surface of the lubricant holding member.   The rolling bearing according to claim 2, wherein the lubricant holding member is made of resin.   The rolling bearing according to any one of claims 1 to 5, which is used for supporting a rotating shaft of a railway vehicle.

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