JP2012172775A - Sealed bearing device - Google Patents

Abstract

A sealed bearing device having high lubrication performance by recirculating grease is provided.
The sealed bearing device is provided with at least one fluid supply passage 40 penetrating from the outer peripheral surface 5b or the side surface 5d of the outer ring 5 to the space between the tapered roller 6 and the sealing mechanism 9A. The fluid can be supplied into the bearing through the fluid supply path 40.
[Selection] Figure 1

Description

  The present invention relates to a sealed bearing device, and more particularly to a sealed bearing device lubricated with grease.

  Conventionally, a sealed bearing device is used for a railway vehicle axle. For example, in Patent Document 1, as shown in FIGS. 4 and 5, two inner rings 4 fitted to the axle in a state in which the back surfaces are applied to an annular spacer 8, and outside of these two inner rings 4 A single outer ring 5 that is fitted to a housing (not shown) opposite to the radial side, and a tapered roller 6 that is held between the inner and outer rings 4 and 5 in a rollable state by a cage 7. A sealed bearing device 10 is described in which a row tapered roller bearing 1 is provided, and an annular member 2 that restricts the movement of the inner ring 4 in the axial direction is provided on both sides of the two inner rings 4.

  In this sealed bearing device 10, a sealing device 9 is provided to prevent leakage of grease filled in the bearing and to prevent water and foreign matter from entering from the outside. The sealing device 9 includes a seal case 11 attached to both sides of the outer ring 5 and an oil seal 12 attached to the inside of the seal case 11, and the seal lip 13 is elastically brought into contact with the slinger 14.

  Furthermore, in Patent Document 1, an annular spacer 15 is provided between the inner ring 4 and the annular member 2 so that grease does not leak even in a high-speed rotation region, and a labyrinth seal is formed between the annular spacer 15 and the seal case 11, The grease is prevented from flowing out to the oil seal 12.

  Further, in the sealed bearing device of Patent Document 2, as shown in FIG. 6, a protrusion 18 projecting radially outward is provided on the outer peripheral surface of the annular member 2, and grease that has flowed from the tapered roller 6 to the oil seal 12 side is provided. It is disclosed that grease leakage is suppressed by causing the centrifugal roller to back flow toward the tapered roller 6 side.

JP 2005-325867 A JP 2009-250393 A

  In such a sealed bearing device 10, the grease sealed in the double row tapered roller bearing 1 is on the side of the seal case 11 due to centrifugal force and pumping action during rotation of the bearing (during relative rotation of the inner and outer rings 4, 5). , It tends to accumulate on the seal case 11 on the outer ring 5 side.

  These Patent Documents 1 and 2 are intended to suppress leakage of grease sealed in the bearing space, but there is room for improvement in terms of improving the lubrication performance. That is, in the sealed bearing device 10 described in Patent Document 1, the grease is not positively supplied to the tapered rollers 6, so that the grease blown off by the centrifugal force of the annular spacer 15 accumulates on the seal case 11. There was a problem of not contributing to lubrication.

  Further, in the sealed bearing device described in Patent Document 2, there is a problem that the grease does not flow to the protruding portion 18 because the grease easily flows to the outer ring side rather than the inner ring side.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a sealed bearing device having high lubricating performance by recirculating grease.

The above object of the present invention is achieved by the following configurations.
A bearing comprising an inner ring, an outer ring, and a rolling element that is arranged to roll between the inner and outer rings;
An annular member that regulates the axial position of the inner ring from at least one axial side of the inner ring;
A sealing mechanism having a seal case that fits to an inner peripheral surface of the outer ring on at least one axial side of the outer ring, and an oil seal that seals between the annular member and the seal case;
A sealed bearing device used for grease lubrication by sealing the inside of the bearing,
There is provided at least one fluid supply path penetrating from an outer peripheral surface or a side surface of the outer ring to a space between the rolling element and the sealing mechanism;
A sealed bearing device characterized in that fluid can be supplied into the bearing from outside through the fluid supply path.

In the above configuration, it is preferable that a backflow prevention valve is provided in the fluid supply path.
In the above configuration, it is preferable that air or lubricating oil is pumped to the fluid supply path so that grease accumulated on the inner diameter side of the outer ring is blown toward the rolling element.
In the above configuration, it is preferable that the fitting portion between the outer ring and the seal case is provided with a grease reservoir that is recessed toward the outer diameter side, and the fluid supply path opens at the bottom surface of the grease reservoir.
Moreover, the said structure WHEREIN: It is preferable that the said fluid supply path inclines toward the said rolling element.

  According to the sealed bearing device of the present invention, by supplying the fluid into the bearing through the through hole, the grease accumulated in the seal case with time can be blown off with the fluid and supplied to the rolling element again. . Thereby, stable lubrication by the grease enclosed in the bearing can be realized.

It is the elements on larger scale of the axial cross section of the sealed bearing apparatus which concerns on 1st Embodiment of this invention. It is the figure seen from the axial direction outer side surface of the outer ring | wheel explaining the arrangement position of a fluid supply path. It is the elements on larger scale of the cross section in the direction orthogonal to the axis of the sealed bearing device concerning a 2nd embodiment of the present invention. It is a fragmentary sectional view of the support structure of the conventional railway vehicle axle described in patent document 1. It is a fragmentary sectional view of the sealed bearing apparatus used for FIG. 10 is a partial cross-sectional view of a sealed bearing device described in Patent Document 2. FIG.

  The sealed bearing device of each embodiment of the present invention will be described below with reference to the drawings. Since the basic structure of the sealed bearing device of the present invention is the same as that of the conventional sealed bearing device shown in FIG. 4, the features of the sealed bearing device of the present invention will be described with reference to FIG. To do. The present invention is different from the sealed bearing device of FIG. 4 in that it does not include the annular spacer 15 and includes a fluid supply path 40 described later.

<First Embodiment>
FIG. 1 is a partially enlarged view of an axial cross section of a sealed bearing device according to a first embodiment of the present invention. The sealed bearing device 10A includes a double row tapered roller bearing 1 (hereinafter simply referred to as a bearing 1), an annular member 2, and a sealing mechanism 9A.

  The bearing 1 is fitted with two inner rings 4 in a state in which the back surfaces are abutted against an annular spacer 8, and a single outer ring 5 is opposed to the outer diameter side of the two inner rings 4. Is not fitted). An annular inner ring raceway surface 4s inclined in a divergent shape along the direction away from the spacer 8 side is formed on the opposing surface of each inner ring 4, while each inner ring 4 is provided on the opposing surface of the outer ring 5. Two annular outer ring raceway surfaces 5s inclined along the four inner ring raceway surfaces 4s are formed.

  On both sides of the two inner rings 4 having such a configuration, an annular member 2 that restricts the axial movement of the inner ring 4 is fitted to an axle (not shown), and one side thereof (FIG. 4). A predetermined preload can be applied to the bearing 1 by applying a pressing body to the annular member 2 on the left side in the middle and tightening with a bolt. In this state, when the axle is rotated, the inner and outer rings 4 and 5 are rotated together with the cage 7 between the raceway surfaces 4s and 5s of the inner and outer rings 4 and 5 while the inner and outer rings 4 and 5 are relatively rotated around the rotation center axis. The plurality of tapered rollers 6 incorporated roll along the raceway surfaces 4s and 5s.

  Further, in order to maintain a constant lubrication performance during rotation of the bearing, grease is sealed inside the bearing. In this case, in order to prevent leakage of grease to the outside of the bearing and to prevent foreign matter (for example, water, dust) from entering the inside of the bearing, the inside of the bearing is disposed outside the bearing on both sides of the inner and outer rings 4 and 5. A sealing mechanism 9A is provided for sealing from the inside. Since the sealing mechanisms 9A provided on both sides of the inner and outer rings 4 and 5 have the same configuration, the sealing mechanism 9A on one side will be described with reference to FIG.

  As shown in FIG. 1, the sealing mechanism 9 </ b> A includes an annular seal case 11 fixed to a fitting groove 5 a that is formed in a concave shape over the entire inner peripheral surface of the outer ring 5 in the axial direction, and the seal And an oil seal 12 interposed between the case 11 and the annular member 2.

  The seal case 11 extends outward in the axial direction while bending inward in the radial direction of the bearing from the cylindrical base end portion 11a. More specifically, the outer diameter side disk part 11b extends radially inward from the axially outer end part of the base end part 11a, and axially outside from the inner diameter side end part of the outer diameter side disk part 11b. The intermediate cylindrical portion 11c extends from the axially outer end portion of the intermediate cylindrical portion 11c to the radially inner side, and the inner diameter side disc portion 11d extends radially inward from the inner diameter side end portion of the inner diameter side disc portion 11d. A cylindrical tip portion 11e extends outward in the axial direction so as to form a labyrinth seal with the annular member 2.

  The oil seal 12 includes a labyrinth forming member 31 having a cylindrical portion 31a fixed to the intermediate cylindrical portion 11c of the seal case 11 and a partition plate portion 31b extending radially inward from an axially inner end of the cylindrical portion 31a. The slinger 32 fixed to the annular member 2, the annular core 33 fixed to the cylindrical portion 31 a of the labyrinth forming member 31 and extending in the direction of the annular member 2, and attached to the extending end of the core 33 And an annular rubber lip 34. An annular presser ring (not shown) is stretched over a part of the lip 34, and the lip 34 is brought into sliding contact with the slinger 32 by the elastic squeezing force of the presser ring. The labyrinth forming member 31 is arranged so that the partition plate portion 31b is substantially flush with the outer diameter side disc portion 11b of the seal case 11 and forms a labyrinth seal with the annular member 2. Has been. The sealing mechanism 9A configured in this manner improves the sealing performance inside the bearing.

  The plurality of tapered rollers 6 incorporated together with the cage 7 between the inner and outer rings 4 and 5 are rotatably held by the cage 7, and the frictional resistance between the cage 7 and the raceway surfaces 4 s and 5 s by grease. Rolling along the raceway surfaces 4s and 5s.

  Further, the grease sealed in the tapered roller bearing 1 is discharged to the seal case 11 side by the centrifugal force and pump action accompanying the rotation during the rotation of the bearing (during the relative rotation of the inner and outer rings 4 and 5), and then on the outer ring 5 side. There is a tendency to deposit on the seal case 11.

  The seal case 11 has a base end portion 11a fitted in the fitting groove 5a, and an outer diameter side disc portion 11b is bent radially inward from an axially outer end portion of the base end portion 11a. Form. The corner 16 of the seal case 11 is an area where the grease sealed in the bearing is easily deposited by centrifugal force.

  Here, the outer ring 5 is provided with a through hole 5c penetrating from the outer end of the outer peripheral surface 5b in the axial direction toward the inner peripheral surface of the outer ring 5 in which the fitting groove 5a is formed. The seal case 11 is also provided with a through hole 11 f communicating with the through hole 5 c of the outer ring 5. The fluid supply path 40 of the present invention is formed by these through holes 5c and 11f.

  The fluid supply path 40 is inclined linearly from the axially outer end of the outer peripheral surface 5 b of the outer ring 5 toward the inner diameter side and toward the inner ring raceway surface 4 s that is a sliding contact portion between the tapered roller 6 and the inner ring 2. ing. In addition, a pump (not shown) or the like is connected to the fluid supply path 40 and a backflow prevention valve (not shown) is provided. Accordingly, by supplying the fluid from the outside of the bearing through the fluid supply path 40 to the inside of the bearing, the grease accumulated at the corner 16 of the seal case 11 can be supplied toward the tapered roller 6, and conversely the grease is inside the bearing. Backflow to the outside through the fluid supply path 40 is restricted by the backflow prevention valve.

  In the sealed bearing device 10A configured as described above, grease accumulates in the corner 16 of the seal case 11 with the passage of time over a long period of time. By supplying the base oil, the grease accumulated at the corner 16 of the seal case 11 is blown off again to the tapered roller 6 side. The grease thus blown off is supplied again between the tapered roller 6 and the raceway surfaces 4s and 5s and contributes to lubrication. Air or grease base oil supplied from the outside of the bearing through the fluid supply passage 40 is preferably pumped. Thereby, the grease deposited on the corner 16 can be more reliably supplied between the tapered roller 6 and the raceway surfaces 4s and 5s.

  Note that the fluid supply path 40 does not have to be provided in a straight line, and may be configured to bend radially inward after extending in the axial direction from the axially outer side surface 5d of the outer ring 5, for example. However, pressure loss can be reduced by providing it in a straight line. Further, at least one fluid supply path 40 may be provided, but it is possible to re-supply the lubricating oil by providing a plurality of fluid supply paths in the circumferential direction, preferably a plurality at a predetermined interval in the circumferential direction.

  Moreover, as shown in FIG. 2, the fluid supply path 40 may be disposed only in the lower part of the gravity direction. As shown in FIG. 2, when gravity is applied, grease tends to accumulate downward in the gravitational direction due to gravity. Therefore, by arranging the fluid supply passage 40 only below the outer ring 5 in the gravitational direction, It becomes possible to re-supply efficiently.

  The fluid supply path 40 is formed from the through hole 5c of the outer ring 5 and the through hole 11f of the seal case 11. However, the fluid supply path 40 is not limited to this, and is formed only from the through hole 5c of the outer ring 5. A portion corresponding to the through hole 5c may be cut out so as not to hinder the flow of the fluid.

  The retainer 7 may be made of metal or resin, and the shape of the retainer 7 can be selected as appropriate. It is preferable to arrange the grease so that it does not overlap the course of the base oil.

Second Embodiment
Next, a sealed bearing device according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a partially enlarged view of a cross section in the direction perpendicular to the axis of the sealed bearing device according to the second embodiment of the present invention. In addition, the same code | symbol or an equivalent code | symbol is attached | subjected to the same or equivalent part as 1st Embodiment, and description is simplified or abbreviate | omitted.

  In the sealed bearing device 10B of the present embodiment, a grease groove 17 that is recessed toward the outer diameter side is provided in the fitting groove 5a formed on the inner peripheral surface of the outer ring 5 and the base end portion 11a of the seal case 11, and fluid The supply path 40 opens at the bottom surface of the grease reservoir 17 so that the outside communicates with the bearing space.

  By providing the grease reservoir 17 in this way, grease can be collected in the grease reservoir 17. Further, by opening the fluid supply passage 40 on the bottom surface of the grease reservoir 17 and supplying or pumping air or grease base oil into the bearing through the fluid supply passage 40 from the outside of the bearing, the grease collected in the grease reservoir 17 is re-applied. It can be blown away to the tapered roller 6 side. The grease thus blown off is supplied again between the tapered roller 6 and the raceway surfaces 4s and 5s and contributes to lubrication.

As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to this, In the range which does not deviate from the meaning, it can change suitably.
For example, the configuration of the sealing mechanism 9A is not limited to this, and a known sealing mechanism can be employed.
Moreover, the sealed bearing device of the present invention can be applied not only to a railway vehicle axle but also to various mechanisms.

1 Double row tapered roller bearing (bearing)
2 annular member 4 inner ring 5 outer ring 5b outer peripheral surface 5d of outer ring side surface 6 of outer ring 6 tapered roller (rolling element)
9A Sealing mechanism 10A Sealed bearing device 11 Seal case 12 Oil seal 40 Fluid supply path

Claims (1)

A bearing comprising an inner ring, an outer ring, and a rolling element that is arranged to roll between the inner and outer rings;
An annular member that regulates the axial position of the inner ring from at least one axial side of the inner ring;
A sealing mechanism having a seal case that fits to an inner peripheral surface of the outer ring on at least one axial side of the outer ring, and an oil seal that seals between the annular member and the seal case;
A sealed bearing device used for grease lubrication by sealing the inside of the bearing,
There is provided at least one fluid supply path penetrating from an outer peripheral surface or a side surface of the outer ring to a space between the rolling element and the sealing mechanism;
A sealed bearing device characterized in that fluid can be supplied into the bearing from outside through the fluid supply path.

Images