JP2008190622A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device capable of keeping constant the lubricating performance of a bearing for a long period by returning the liquefied base oil reserved in a seal part space again into a bearing inner space. <P>SOLUTION: This sealing device is used for a bearing for a rolling stock bearing having a rotating ring (inner ring 3) secured to and rotated together with an axle, a stationary ring (outer ring 1) disposed opposite to the rotating ring and kept in a non-rotating state, and rolling elements 5 rollingly assembled between the stationary ring and the rotating ring. The sealing ring seals the bearing inner space demarcated between the stationary ring and the rotating ring. The sealing device comprises a partition plate 26 forming a seal part space S2 separated from the bearing inner space S1 and a sealing member 27 positioned in the seal part space in the state of being in slidable contact with the rotating ring. A through hole 26h so formed through a part of the partition plate as to allow the bearing inner space to communicate with the seal part space is formed in the partition plate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sealing device applied to a bearing that rotatably supports an axle of a railway vehicle.

  Conventionally, various types of tapered roller bearings (see Patent Document 1) have been used for railway vehicle axles. As an example, the tapered roller bearing shown in FIG. 2A is always kept in a non-rotating state. The stationary wheel (outer ring 1), the rotating wheel (inner ring 3) rotatably disposed opposite the stationary wheel (outer ring 1), and the outer ring 1 and the inner ring 3 are opposed to each other in a circumferential direction. A plurality of rolling elements (rollers) 5 and a plurality of rolling elements (rollers) 5 that are rotatably incorporated along the formed raceway surfaces 1 s and 3 s are rotatably held one by one, while the outer inner ring 1 , 3 and a cage 11 made of, for example, resin is provided.

  In such a bearing, two inner rings 3 are fitted to the railcar axle (rotary shaft) 13 with the back surfaces of the inner ring 3 abutting against an annular spacer 15, and face the outside of the two inner rings 3. A single (integrated) outer ring 1 is fitted in a housing (not shown). In this case, a single annular inner ring raceway surface 3s inclined in a divergent shape along the direction away from the spacer 15 side is formed on the facing surface of each inner ring 3, while the outer ring 1 faces Two annular outer ring raceway surfaces 1s inclined along the inner ring raceway surface 3s of each inner ring 3 are formed on the surface. In some cases, the spacer 15 is not interposed between the inner rings 3.

  Further, on both sides of each inner ring raceway surface 3s, annular flanges 7 and 9 are projected along the raceway surface 3s, and the diameters of the projecting ends 7e and 9e are different from each other. More specifically, in each inner ring 3, the flange portion 7 on the spacer 15 side (hereinafter referred to as the small diameter flange portion 7) becomes a relatively small diameter protruding end 7e, and the protruding end 9e on the counter spacer 15 side (hereinafter referred to as the protruding portion 9e). The large-diameter flange 9) is a protruding end 9e having a relatively larger diameter than the flange 7 on the spacer 15 side.

  On both sides of the two inner rings 3 having such a configuration, annular oil draining members 17 and 19 that constitute a rotating wheel together with the inner ring 3 are fitted to a railway vehicle axle (rotating shaft) 13, respectively. The tapered roller bearing is fixed to the axle by applying the pressing body 21 in the axial direction to the oil draining member 17 on one side (the left side in the middle of FIG. 2A) and tightening with the bolt 23. In this state, when the railcar axle (rotary shaft) 13 is rotated, the cage is placed between the raceway surfaces 1s and 3s of the outer inner rings 1 and 3 while the outer inner rings 1 and 3 rotate relative to each other (bearing is rotating). A plurality of rolling elements (rollers) 5 incorporated together with 11 roll along the raceway surfaces 1s and 3s while being held and guided by the guide surfaces 7s and 9s of the flanges 7 and 9, respectively.

  Further, in the tapered roller bearing described above, a predetermined amount of lubricant (for example, grease) is sealed inside the bearing in order to keep the lubrication performance constant during the rotation of the bearing. In this case, in order to prevent lubricant (grease) from leaking to the outside of the bearing and to prevent foreign matter (for example, water and dust) from entering the bearing, both sides of the outer inner rings 1 and 3 are stationary. A sealing device is provided for sealing the bearing internal space S1 defined between the ring (outer ring 1) and the rotating ring (inner ring 3). Since the configuration of the sealing device is the same for both, hereinafter, the sealing device on the right side in FIG. 2A will be described.

  As shown in FIG. 2 (b), the sealing device has a base end portion 25 e fixed to the stationary wheel (outer ring 1) and a tip end portion 25 t in a non-contact state with respect to the oil draining member (rotating wheel) 19. The annular seal case 25 is positioned, a partition plate 26 that forms a seal portion space S2 that is isolated from the bearing internal space S1, and a sealing member 27 that is positioned in the seal portion space S2. . In this case, the seal case 25 extends so as to cover the bearing internal space S1 and the seal portion space S2 from the base end portion 25e toward the tip end portion 25t. The partition plate 26 has a proximal end 26 e fixed to the seal case 25 and a distal end 26 t positioned in a non-contact state with respect to the oil draining member (rotating wheel) 19.

  The sealing member 27 includes an annular mandrel 27 a fixed to the base end side 26 e of the partition plate 26, and an annular rubber member 27 b that is covered by the mandrel 27 a and extends toward the oil draining member (rotating wheel) 19. And an annular elastic ring 27c that is stretched over the extended end of the rubber member 27b. In this case, the tightening force of the elastic ring 27 c acts on the extending end of the rubber material 27 b, so that the extending end is always in contact with the oil draining member (rotating wheel) 19. .

  According to such a sealing device, the seal case 25 and the sealing member 27 are combined with each other to improve the sealing performance inside the bearing, and the lubrication performance during the rotation of the bearing is kept constant. At this time, the plurality of rolling elements (rollers) 5 incorporated together with the retainer 11 between the outer inner rings 1 and 3 are rotatably held by the retainer 11 one by one, while being retained by the lubricant (grease). And rolling along the raceway surfaces 1s and 3s while reducing the frictional resistance between the raceway surfaces 1s and 3s.

  By the way, the lubricant (grease) sealed in the bearing as described above is agitated while the bearing is rotating, and the base oil component is vaporized by the agitation heat generated at that time. The vaporized vapor passes from the bearing internal space S1 having a relatively high temperature through the gap between the tip side 26t of the partition plate 26 and the oil draining member (rotating wheel) 19 to the seal portion space S2 having a relatively low temperature. Moving. At this time, in the seal portion space S2, the vapor of the base oil is cooled and liquefied, but the liquefied base oil is accumulated in the seal portion space S2 as it is.

In this case, when the amount of the liquefied base oil accumulated in the seal portion space S2 increases, the amount of lubricant inside the bearing decreases accordingly, and as a result, it is difficult to maintain the bearing's lubricating performance constant over a long period of time. There is a risk of becoming. Further, the liquefied base oil in the seal portion space S <b> 2 may leak to the outside of the bearing from between the extended end of the sealing member 27 and the oil draining member (rotating wheel) 19. Therefore, it is desired to develop a technology capable of maintaining the lubricating performance of the bearing constant over a long period of time by returning the liquefied base oil accumulated in the seal space S2 to the bearing internal space S1 again. No such technology is currently known.
JP 2006-316838 A

  The present invention has been made in order to meet such demands, and its purpose is to return the liquefied base oil accumulated in the seal portion space to the bearing internal space again, thereby making the bearing lubrication performance constant over a long period of time. It is to provide a sealing device that can be maintained.

  In order to achieve this object, the present invention provides a rotating wheel that is fixed to an axle and rotates together, a stationary wheel that is disposed opposite the rotating wheel and is maintained in a non-rotating state, and a stationary wheel and a rotating wheel. A sealing device for sealing a bearing internal space that is used for a railway vehicle axle bearing provided with a plurality of rolling elements that are incorporated in a freely rolling manner, and is partitioned between a stationary wheel and a rotating wheel. A partition plate constituting a seal portion space isolated from the bearing inner space, and a sealing member positioned in the seal portion space while being in sliding contact with the rotating wheel. A through hole formed through a part of the partition plate is provided so as to communicate with the seal portion space.

  In the present invention, the sealing device includes a seal case whose base end is fixed to the stationary wheel and whose front end is positioned in a non-contact state with respect to the rotating wheel. It is fixed to the case. In this case, the sealing member is provided with an air vent hole formed through a part of the sealing member so as to adjust the air pressure in the seal portion space. Further, in a state where the axle is positioned horizontally, the through hole of the partition plate is disposed on the lower side in the vertical direction, and the air vent hole of the sealing member is disposed on the upper side in the vertical direction.

  According to the sealing device of the present invention, the lubricating performance of the bearing can be maintained constant over a long period of time by returning the liquefied base oil accumulated in the seal portion space to the bearing internal space again.

  Hereinafter, a sealing device according to an embodiment of the present invention will be described with reference to the accompanying drawings. Since the sealing device of the present embodiment is an improvement of the above-described railcar axle bearing (FIG. 2A), only the improvement will be described below.

  As shown in FIGS. 1 (a) and 1 (b), in the sealing device of the present embodiment, the partition plate 26 is provided with the partition plate 26 so that the bearing internal space S1 and the seal portion space S2 communicate with each other. A through hole 26h formed through a part thereof is provided. In this case, the through hole 26 h is preferably provided in the vicinity of the seal case 25 on the base end side 26 e of the partition plate 26. Moreover, since the axle of a railway vehicle is normally positioned in a horizontal state, in this state, it is preferable that the through-hole 26h is disposed on the vertically lower side.

  Thus, by providing the through hole 26h in the partition plate 26, the base oil that has been liquefied and accumulated in the seal portion space S2 can be returned from the through hole 26h to the bearing internal space S1. In this case, the liquefied base oil tends to accumulate on the vertical lower side of the seal portion space S2, for example, due to its own weight or gravity. Therefore, the through hole 26h is provided on the base end side 26e (near the seal case 25) of the partition plate 26, and the through hole 26h is arranged on the vertical lower side, so that the liquefied base oil accumulated in the seal portion space S2 can be efficiently used. It can be well returned to the bearing internal space S1.

  Here, it is assumed that the liquefied base oil has accumulated on the vertical lower side (near the through hole 26h) of the seal portion space S2. In this state, when there is no lubricant (grease) on the bearing inner space S1 side of the through hole 26h, the liquefied base oil flows back into the bearing inner space S1 from the through hole 26h. On the other hand, when a lubricant (grease) is present on the bearing inner space S1 side of the through hole 26h, the lubricant (grease) has a property of absorbing the liquefied base oil. It is returned to the bearing internal space S1 while being absorbed by the lubricant (grease) from the through hole 26h.

  As described above, according to the present embodiment, by providing the through hole 26h vertically below the partition plate 26, the liquefied base oil accumulated in the seal portion space S2 can be returned to the bearing internal space S1 again. As a result, the amount of lubricant inside the bearing can be constantly maintained (or suppressed), and as a result, the lubrication performance of the bearing can be maintained constant over a long period of time. In this case, since liquefied base oil does not accumulate excessively in seal part space S2, it can prevent that liquefied base oil of seal part space S2 leaks outside a bearing.

  Further, in the above-described embodiment, the shape, size, or number of the through-holes 26h is not particularly mentioned. However, if the liquefied base oil accumulated in the seal portion space S2 can be returned to the bearing internal space S1 again. There is no particular limitation. That is, the shape of the through hole 26h is exemplified by a semicircular shape in the drawing, but various shapes such as a mesh shape, a rectangular shape, a circular shape, and a triangular shape can be applied. Further, the size of the through hole 26h exemplifies a size that occupies a part of the vertical lower side of the partition plate 26 in the drawing. For example, the vertical lower side of the partition plate 26 is widened along the circumferential direction. You may let them. Furthermore, although the number of through holes 36h is one in the drawing, it may be two or more at predetermined intervals (for example, equal intervals) in the circumferential direction.

  Also, depending on the purpose and environment of use of the sealing device, in order to adjust the atmospheric pressure in the seal portion space S2, for example, as shown in FIG. May be formed. In this case, it is preferable that the air vent hole 27h is arranged vertically upward. Note that the shape, size, or number of the air vent holes 27h is arbitrarily set according to, for example, the shape and size of the sealing member 27, and is not particularly limited here.

  In addition, as a method of fixing the partition plate 26 and the sealing member 27 to the seal case 25, as an example in the drawing, the mandrel 27a of the sealing member 27 is fixed to the base end side 26e of the partition plate 26 fixed to the seal case 25. However, instead of this, the mandrel 27a of the sealing member 27 may be fixed to the seal case 25, and the base end side 26e of the partition plate 26 may be fixed inside the mandrel 27a.

  In the above-described embodiment, the description has been made on the assumption that the outer ring 1 is a stationary ring. On the contrary, the sealing device of the present invention is applied to a bearing having the inner ring 3 as a stationary ring. Needless to say, you can. In addition, although “rollers” are assumed as the rolling elements 5, the same effects as described above can be realized even if “balls” are applied instead.

(a) is sectional drawing which partially expands and shows the structure of the sealing device which concerns on one embodiment of this invention, (b) is a top view of the sealing device seen from the bearing inside, (c) is a bearing The top view of the sealing device seen from the outside. (a) is sectional drawing which shows the structure of the bearing for railroad vehicle axles, (b) is sectional drawing which expands and shows a part of structure of the conventional sealing device.

Explanation of symbols

1 stationary wheel (outer ring)
3 Rotating wheel (inner ring)
5 Rolling elements (rollers)
26 Partition plate 26h Through-hole 27 Sealing member S1 Bearing internal space S2 Seal portion space

Claims (4)

A rotating wheel that is fixed to the axle and rotates together, a stationary wheel that is disposed opposite to the rotating wheel and maintained in a non-rotating state, and a plurality of rolling elements that are rotatably incorporated between the stationary wheel and the rotating wheel A sealing device for sealing a bearing internal space that is partitioned between a stationary wheel and a rotating wheel.
A partition plate constituting a seal portion space isolated from the bearing internal space, and a sealing member positioned in the seal portion space in a state of sliding contact with the rotating wheel,
A sealing device, wherein the partition plate is provided with a through-hole formed through a part of the partition plate so as to communicate the bearing internal space and the seal portion space. The base end portion is fixed to the stationary wheel, and the distal end portion is provided with a seal case positioned in a non-contact state with respect to the rotating wheel,
The sealing device according to claim 1, wherein the partition plate and the sealing member are fixed to a seal case.   The sealing member according to claim 1 or 2, wherein the sealing member is provided with an air vent hole formed through a part of the sealing member so as to adjust an air pressure in the seal portion space. apparatus.   4. The sealing according to claim 3, wherein in a state where the axle is horizontally positioned, the through hole of the partition plate is disposed vertically downward, and the air vent hole of the sealing member is disposed vertically upward. apparatus.

Images