JP2009138879A - Railroad vehicle axle bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a railroad vehicle axle bearing device from which water or foreign matters are actively discharged. <P>SOLUTION: The railroad vehicle axle bearing device comprises an inner ring 12 fixed to an axle 20, an outer ring 14 fixed to a shaft box 30, rolling elements 16 laid between the inner ring 12 and the outer ring 14, a cage 18 for holding the rolling elements 16 at predetermined spaces, a rotary member 24 arranged between a shoulder face 20a of the axle 20 and the inner ring 12, and a stationary member 32 fixed to the shaft box 30. An annular protruded strip 24a provided on the outer periphery of the rotary member 24 and an annular groove 34 provided in the inner periphery of the stationary member 32 form a labyrinth seal. At least one protrusion 24d is formed on the annular protruded strip 24c, and a through-hole 36 is provided in the annular groove 34. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a railway vehicle axle bearing device, that is, a bearing device for supporting an axle of a railway vehicle.

In conventional railway vehicle axle bearing devices, as seen in Patent Document 1, a labyrinth groove is provided on the outer peripheral surface of a collar ring that is continuously provided at the inner ring end, and an outer cylinder fitting is protruded from the outer ring end to provide a non-contact type. A structure in which an oil seal mechanism is formed is common. By making the clearance formed between the collar ring and the outer cylinder fitting into a complicated flow path, the fluid, that is, the outflow of the lubricant sealed inside the bearing, using the expansion / contraction resistance, viscous friction resistance, etc. It is a mechanism that suppresses intrusion of foreign matter from. Since such a labyrinth seal has a non-contact structure, the seal portion is not damaged by heat generation and wear.
Japanese Utility Model Publication No. 5-32215

  A labyrinth seal used in a conventional bearing device for a railway vehicle axle is provided with a plurality of grooves running in the circumferential direction, and the gap is complicated by the unevenness formed between the grooves so that water and foreign matter cannot easily enter. ing. However, although various labyrinth seal shapes are known, since it is necessary to severely manage a wide and narrow repeated gap structure, it is difficult to configure the labyrinth seal with a seal attached to the bearing.

In addition, since the labyrinth seal basically communicates with the outside of the bearing device, when it is applied to a bearing device for a railway vehicle axle, a reliable sealing effect can be obtained during heavy rain, when the railway vehicle is stopped, or at a low speed. Therefore, there is a possibility that the lubricant sealed inside the bearing may flow out and foreign matter may enter from the outside. In other words, it is a situation that some foreign matter cannot be avoided. Moreover, since it has a complicated clearance, once water or foreign matter enters the clearance, it can be considered to stay inside. In particular, in areas with heavy rain, heavy rainfall, and heavy snowfall, there is a concern about intrusion into the bearings.
On the other hand, in recent years, the speed of railway vehicles has been increased, and there is a concern about heat generation due to sliding between the seal lip and the seal surface in the contact type seal.

  An object of the present invention is to eliminate the above-mentioned problems and further improve the sealing performance of a railway vehicle axle bearing device.

  According to the present invention, a labyrinth seal structure is provided on the outer periphery of the rotating rear lid, and foreign matter such as water that has entered the labyrinth seal portion is scraped out to promote discharge, thereby preventing the foreign matter from staying in the labyrinth seal portion. Is.

  That is, the railway vehicle axle bearing device of the present invention holds an inner ring fixed to the axle, an outer ring fixed to the axle box, a rolling element interposed between the inner ring and the outer ring, and the rolling element at a predetermined interval. A cage, a rotating member disposed between the shoulder surface of the axle and the inner ring, and a stationary member fixed to the axle box, an annular protrusion provided on an outer periphery of the rotating member, and an inner periphery of the stationary member A labyrinth portion is formed with an annular groove provided on the annular groove, a protrusion protruding outward is provided on the annular protrusion, and a through hole is provided in the annular groove.

Here, the stationary member corresponds to, for example, a metal ring fixed to the axle box, and the rotating member corresponds to, for example, a rear lid fixed to the axle.
Since the rotating member is a member that rotates together with the axle, the protrusion moves in the circumferential direction in the annular groove of the stationary member with the rotation, and as a result, the water and other foreign matters that have entered the labyrinth portion are scraped out, and the through hole Forcibly discharged from the outside. When the rotating member having the protrusion rotates, dynamic pressure is generated by the action of centrifugal force, and the pressure on the outer peripheral side of the protrusion increases. Therefore, the foreign substance existing in the labyrinth portion can be discharged and the action of preventing the entry from the outside can be obtained.

  The number and arrangement of the protrusions are arbitrary, but it is desirable that the setting takes into account the rotational balance. The shape of the protrusion is arbitrary, but an example is a gear shape. In order to exert its effect of scraping foreign matter present in the labyrinth part with rotation, the protrusion protrudes from the annular protrusion to the outer diameter side, and protrudes in the axial direction from the side wall of the annular protrusion. It may be.

  By adding an elastically deformable lip to the tip of the protrusion, it is possible to promote the action of scraping out foreign matter and positively discharging it. The lip having such an action is preferably made of an elastic material such as rubber or plastic.

One or more through holes are provided. As for the arrangement of the through holes, it is desirable to arrange them at the lower part of the bearing device in order to fully exhibit the action of discharging the foreign matter existing in the labyrinth portion. If expressed in a clock display, it may be provided in the vicinity of 6 o'clock or in a region from around 4 o'clock to 7 o'clock.
Since the discharge action of the through hole is exhibited when the through hole communicates the inside and the outside of the annular groove, the direction of the through hole is not limited as long as such an action is obtained. That is, the radial direction, axial direction, or diagonal of the rotating member may be used. Discharge is promoted by making the cross-sectional area of the through hole smaller outside than inside.

According to this invention, in addition to the contact-type seal by the oil seal, the seal effect is improved by using a non-contact seal by the labyrinth seal in combination. In addition, it is possible to positively scrape foreign matter that has entered the labyrinth portion by centrifugal force and wedge action.
When the centrifugal force acts, the foreign matter and water around the rear lid move to the outer diameter side along the protrusion, and when the protrusion passes through the through hole, it is pushed into the through hole and then discharged to the outside.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a longitudinal section of a railway vehicle axle bearing device using a double-row tapered roller bearing. A double-row tapered roller bearing (hereinafter, also simply referred to as a bearing) 10 includes a pair of inner rings 12, an outer ring 14, a plurality of rolling elements 16, and a pair of cages 18 as main components.

The inner ring 12 uses a pair of single-row inner rings having a track on the outer periphery, and is fitted to an axle 20 indicated by a two-dot chain line in a state adjacent to the axial direction.
The outer ring 14 is a double-row outer ring having two rows of raceways on the inner periphery, and is attached to the bearing housing.
Here, the rolling element 16 is a tapered roller and is interposed between the raceway of the inner ring 12 and the raceway of the outer ring 14 so as to be freely rollable.
The cage 18 holds the rolling elements 16 at predetermined intervals in the circumferential direction by accommodating the rolling elements 16 in pockets formed at predetermined intervals in the circumferential direction.

  A seal device including a seal case 26 and an oil seal 28 is disposed at both ends of the bearing 10, and grease is sealed inside the bearing 10 sealed with the oil seal 28. The seal case 26 has a stepped cylindrical shape, and has large diameter end portions fitted to the inner peripheral surfaces of both ends of the outer ring 14. The oil seal 28 is held at the middle diameter step of the seal case 26. The oil seal 28 is a contact type having a well-known seal lip. The seal lip of the oil seal 28 is brought into elastic contact with the seal surface formed on the rotating member. Here, the oil drain 22 and the rear lid 24 correspond to rotating members, the oil drain 22 is provided with a seal surface 22a, and the rear lid 24 is provided with a seal surface 24a.

  A labyrinth seal is formed between the seal case 26 and the oil drain 22 and between the seal case 26 and the rear lid 24. A labyrinth seal is defined as creating a curved path between a rotating part and a stationary part to reduce leakage (JIS B 0119). On the oil drain 22 side, a minute clearance is formed between the inner peripheral surface of the small diameter end of the seal case 26 and the outer peripheral surface of the oil drain 22. On the rear lid 24 side, the small-diameter end portion of the seal case 26 is made to enter an annular groove 24b formed on the side wall of the rear lid 24 to form a minute gap therebetween.

  In FIG. 1, an oil drain 22 and a rear cover 24 are arranged on both sides in the axial direction of the pair of inner rings 12 in a state where the bearing 10 is incorporated in the axle 20. The rear cover 24 is put on the shoulder surface 20a of the axle 20 and a nut (not shown) is fastened to the male screw portion 20b of the axle 20 to fix the bearing 10 on the axle 20. In addition, it may replace with a nut and may fix the part called a front cover to the end surface of the axle 20 using a volt | bolt. Although not shown in FIG. 1, the wheel is fixed closer to the center of the axle than the rear lid 24. The portion with the rear lid 24 is exposed to the outside and is in an environment where water and dust are easily applied.

  A metal ring 32 is attached to the axle box 30. The metal ring 32 occupies an axial position corresponding to the rear lid 24 and forms a labyrinth portion therebetween. That is, a plurality of annular protrusions 24 c are formed on the outer periphery of the rear lid 24, and a plurality of annular grooves 34 are formed on the inner periphery of the metal ring 32. And the so-called labyrinth in which wide and narrow annular gaps appear alternately in the axial direction is formed by arranging the annular ridges 24c of the rear lid 24 partially into the annular grooves 34 of the metal ring 32. As shown in FIG. 2, it is preferable that the metal ring 32 is divided into two parts such as a split type in consideration of mounting and is fixed with bolts. As can be seen from FIG. 1 and FIG. 2, the upper half of the metal ring 32 and the axle box 30 are fitted together with an inlay to perform axial and radial positioning.

  In addition, all the annular grooves called annular protrusions have a vertical cross-sectional shape similar to a square screw. And between adjacent annular ridges becomes an annular groove, and similarly, between adjacent annular grooves becomes an annular ridge. The number of stages of these annular grooves / ridges can be arbitrarily set according to the width of the bearing device.

As shown in FIG. 3, a protrusion 24 d is provided on the annular protrusion 24 c of the rear lid 24. Although the figure shows an example in which three protrusions 24d are provided, the number of protrusions 24d is arbitrary, and a larger number may be provided in consideration of the balance and discharging efficiency during rotation. FIG. 3 shows an example in which the phase of the protrusion 24d in the A cross section and the protrusion 24d in the B cross section are changed in consideration of the rotational balance.
The shape of the protrusion 24d may be a gear shape as shown in FIG. In this case, the number of teeth can be arbitrarily set in consideration of manufacturability and the scraping effect.

  When the rotation direction is constant, as shown in FIG. 5, it is also effective to adopt a shape that enhances the discharge effect with respect to the rotation direction. As shown in the figure, by providing the protrusion 24d with a slope, when the protrusion 24d passes through the through hole 36, the action of pushing out foreign substances and water accompanying the vicinity of the protrusion 24d to the outside by the slope works, and the protrusion 24d is located on the outer diameter side. Since the atmosphere at the tip of the protrusion 24 d is in a compressed state, when those foreign substances and water approach the through hole 36, they are drawn into the through hole 36. Since the pressure increases toward the tip of the wedge-shaped space formed by the slope of the protrusion 24d and the inner peripheral surface of the metal tube 32, the water immediately moves to the side when the space such as the through hole 36 expands there. To do.

  In an environment where a large amount of water enters, it is desirable to increase the discharge efficiency by providing a lip at the tip of the protrusion 24d. An elastically deformable lip made of an elastic material such as rubber or plastic may be used and elastically contacted with the annular groove of the metal ring.

  The annular ridge between the annular grooves 34 of the metal tube 32 can take an effective cross-sectional shape against entry from the outside. Specific examples include a circle (FIG. 6A), a triangle (FIG. 6B), and the like, but any other shape can be employed.

  An annular groove is formed between adjacent annular ridges 34, and a through hole 36 is provided in the lower part of the annular groove. In FIG. 1, a through-hole 36 appears at the 6 o'clock position on the clock display. When the rear lid 24 rotates, the tip of the protrusion 24d scrapes out water or the like in the gap and discharges it from the lower through hole 36 to the outside. One or a plurality of through holes 36 may be provided as necessary. FIG. 7 shows an example in which the through holes 36 are arranged at intervals of 5 minutes from 4 o'clock to 7 o'clock on the clock display.

  By making the cross-sectional area of the through hole 36 smaller on the outside air side than on the bearing inside side, discharge from the inside to the outside is promoted. That is, by setting the relationship so that (bearing internal pressure) × (cross-sectional area inside the bearing of the through hole)> (atmospheric pressure) × (cross-sectional area outside the through-hole), the pressure inside the bearing is low. Even in this case, water or the like is easily discharged from the through hole 36.

It is a longitudinal cross-sectional view of a railway vehicle axle bearing device. It is an II arrow directional view of FIG. (A) is AA sectional drawing of FIG. 1, (B) is BB sectional drawing of FIG. (A) is the fragmentary figure which shows the deformation | transformation aspect of the rear cover of FIG. 1, (B) is BB sectional drawing of FIG. 4 (A). It is sectional drawing similar to FIG. 4 (B) which shows another deformation | transformation aspect of a back cover. (A) (B) is sectional drawing similar to FIG. 4 (A) which shows another Example of a metal ring. It is a front view of a metal ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bearing 12 Inner ring 14 Outer ring 16 Roller 18 Cage 20 Axle 20a Shoulder surface 20b Male thread part 22 Oil drain 24 Rear cover 24a Seal surface 24b Annular groove 24c Annular ridge 24d Protrusion 26 Seal case 28 Oil seal 30 Axle box 32 Metal ring 34 Annular groove 36 Through hole

Claims (6)

Between the inner ring fixed to the axle, the outer ring fixed to the axle box, the rolling element interposed between the inner ring and the outer ring, the cage that holds the rolling element at a predetermined interval, and the shoulder surface of the axle and the inner ring And a stationary member fixed to the axle box,
A labyrinth portion is formed by an annular protrusion provided on the outer periphery of the rotating member and an annular groove provided on the inner periphery of the stationary member, and a protrusion protruding outward is provided on the annular protrusion, and the annular Railway vehicle axle bearing device having a through hole in the groove.   2. The bearing device for a railway vehicle axle according to claim 1, wherein the projections scrape foreign matter in the labyrinth portion with the rotation of the axle and forcibly discharge the foreign matter from the through hole to the outside.   The bearing device for a railway vehicle axle according to claim 1, wherein a lip that can be elastically deformed is added to a tip of the projection.   The railcar axle bearing device according to claim 1, wherein the protrusion has a gear shape.   The bearing device for a railway vehicle axle according to claim 1, wherein the through hole is disposed at a lower portion of the bearing device.   The railway vehicle axle bearing device according to claim 1, wherein a cross-sectional area of the through hole is smaller on the outer side than on the inner side of the bearing.

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