JP2005299753A - Sealing device for bearing for axle of rolling stock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent adsorption of a dust lip while achieving original performance for preventing grease leakage and intrusion of water and dust of a sealing device for a bearing for an axle of a rolling stock to reduce heat generation. <P>SOLUTION: This sealing device for the bearing for the axle of the rolling stock has a rubber-made seal main body 34, which has a disc part 36 extending in the radial direction, a main lip 38 extending in substantially axial direction from an inside diameter end part of the disc part 36, and the dust lip 40 extending on the opposite side to the main lip 38 from the inside diameter end part of the disc part 36. The dust lip 40 constitutes a non-contact seal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing device for a bearing for a railway vehicle axle.

  As shown in FIG. 5, the railway vehicle axle bearing holds the outer bearing ring 2, the pair of bearing inner rings 4, the double row tapered rollers 6, and the tapered rollers 6 in each row at predetermined intervals in the circumferential direction. The cage 8 is constituted as a main component. The bearing outer ring 2 has a double-row raceway formed on the inner peripheral surface thereof, and is incorporated in a shaft box (not shown). On the other hand, the bearing inner ring 4 is fitted to the shaft end portion of the axle 10, and a track is formed on the outer peripheral surface. A tapered roller 6 is interposed between the raceway of the bearing outer ring 2 and the raceway of the bearing inner ring 4. Sealing devices 20 are attached to both ends of the bearing outer ring 2. With a pair of bearing inner rings 4 sandwiched between them, an oil drain 12 is disposed on the shaft end side of the axle, and a rear lid 14 is disposed on the opposite side. The seal of the sealing device 20 is in sliding contact with the oil drain 12 and the rear lid 14 with a predetermined tightening margin.

  As shown in FIG. 6, the sealing device 20 includes a case 16, a metal ring 18, a cored bar 22, and a seal 24. The case 16 is made of metal and has a three-stage cylindrical shape. The case 16 is press-fitted into the inner peripheral surface of the bearing outer ring 2 at the large-diameter end, and the outer diameter of the rear lid 14 (or oil drainer 12) at the small-diameter end. A labyrinth seal is formed between the surfaces. The metal ring 18 has an inverted L-shaped cross section and is composed of a cylindrical portion and a disc portion, and is fitted to the inner diameter surface of the middle diameter portion of the case 16 at the cylindrical portion. A seal metal core 22 having an inverted L-shaped cross section is fitted inside the metal ring 18, and the case 16, the metal ring 18, and the metal core 22 have a three-layer structure.

  The seal 24 is made of a heat-resistant rubber material and is integrally baked on a disk portion 23 extending in the radial direction of the cored bar 22. The seal 24 is composed of a main lip 26a, a dust lip 26c, and a cylindrical portion 26b for connecting both lips. Reference numeral 28 denotes a garter spring mounted on the outer periphery of the main lip 26a.

Generally, in a railway vehicle axle bearing, the inner side of the bearing is the main lip 26a, and the outer side of the bearing is the dust lip 26c. The main lip 26a has a fitting force of the main lip 26a expressed by the difference between the outer diameter of the oil drain 12 and the rear lid 14 and the inner diameter of the lip so that the lubricant (grease) inside the bearing does not flow out. A predetermined tightening force is secured by the reduced diameter force of the garter spring 28. On the other hand, the dust lip 26c gives a predetermined tightening force only by the fitting force of the dust lip 26c expressed by the difference between the outer diameter of the oil drainer 12 and the rear lid 14 and the inner diameter of the tip of the lip. Prevents foreign matter and moisture from entering. Normally, grease is applied to the annular space between the main lip 26a and the dust lip 26c for sealing lip lubrication. Although FIG. 6 shows an example in which the dust lip 26c is double, it may be single. In FIG. 6, reference symbol PA denotes a bearing inner space, reference symbol PB denotes an outer pressure chamber PB formed by the metal ring 18, the metal core 22, and the seal body 24, and reference symbol PC denotes between the main lip 26a and the dust lip 26c. In addition to indicating the inner pressure chambers formed in each, the pressure of the space or chamber is also shown.
JP 2002-181057 A (paragraph numbers 0006, 0007, FIGS. 11 and 12)

  A conventional sealing device for a railway vehicle axle bearing device has a contact-type seal structure for both the main lip and the dust lip. However, due to variations in tightening, the pressure PB inside the bearing and the pressure PC between the seal lips 26a and 26c. This causes the difference (pressure difference) between the two and the dust strip 26c to be adsorbed, which may cause a heat generation problem.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sealing device for a bearing for a railway vehicle axle that prevents adsorption of dust lip, reduces heat generation, and prevents leakage of grease and moisture / dust, which are the original functions. It is to provide.

The present invention is a railway vehicle axle bearing sealing device 30 having a rubber seal main body 34, the seal main body 34 having a radially extending disk portion 36, and the disk portion 36. A main lip 38 extending substantially axially from the inner diameter end, and a dust lip 40 extending from the inner diameter end of the disk portion 36 to the opposite side of the main lip 38; It constitutes a seal.

  A labyrinth may be formed between the inner peripheral surface 46 of the dust lip 40 and the rotating body (14).

  A labyrinth may be formed between the end face of the dust lip 40 and the rotating body (14).

  A plurality of recesses 48 arranged in the circumferential direction can be provided in the inner peripheral surface 46 of the dust lip 40 (Claim 4). By providing the recess 48, a dynamic pressure effect is generated with rotation, and entry of water and foreign matter from the outside can be prevented.

  On the inner circumferential surface of the dust lip 40, circumferentially extending ribs 56 provided with cut-outs 58 in at least one circumferential direction are arranged in parallel and out of phase so that the cut-outs 58 are not aligned. (Claim 5). By adopting such a configuration, the flow resistance becomes larger than the state in which the cut-outs 58 are aligned, and foreign matter or the like to enter is less likely to flow.

  You may provide the protrusion 50 which protruded in the outer-diameter side at the edge part of the said case 16 over the perimeter (Claim 6). As a result, an annular groove 54 is formed, and the intruded water can be guided and discharged from the upper part to the lower part, so that the discharge of water can be actively promoted.

  Furthermore, an annular recess 15 for receiving the protrusion 50 may be provided in the rotating body (14), and a labyrinth may be formed by the protrusion 50 and the recess 15 (Claim 7).

  According to this invention, by making the dust lip 40 non-contact, adsorption is prevented and low heat generation can be expected. Further, by forming a labyrinth between the inner peripheral surface 46 or the end surface of the dust lip 40 and the rotating body (14), intrusion of water or the like from the outside can be prevented. Furthermore, a labyrinth structure can be formed by the interaction between the peripheral structure and the position / shape of the case, and a sealing effect is exhibited.

  Embodiments of the present invention will be described below with reference to the drawings. Here, FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and corresponds to a partially enlarged view of the railway vehicle axle bearing shown in FIG. 2A is an enlarged view of the sealing device in FIG. 1, and FIG. 2B is a view taken in the direction of arrow B in FIG. FIG. 3 shows another embodiment.

  As shown in FIG. 4, the railway vehicle axle bearing holds the bearing outer ring 2, the pair of bearing inner rings 4, the double-row tapered rollers 6, and the tapered rollers 6 in each row at predetermined intervals in the circumferential direction. The cage 8 is constituted as a main component. The bearing outer ring 2 forms a double-row raceway on the inner peripheral surface, and is incorporated in a shaft box (not shown). On the other hand, the bearing inner ring 4 is fitted to the shaft end portion of the axle 10, and a track is formed on the outer peripheral surface. A tapered roller 6 is interposed between the raceway of the bearing outer ring 2 and the raceway of the bearing inner ring 4. Sealing devices 30 are attached to both ends of the bearing outer ring 2. With a pair of bearing inner rings 4 sandwiched between them, an oil drain 12 is disposed on the shaft end side of the axle, and a rear lid 14 is disposed on the opposite side. The seal lip of the sealing device 30 is in sliding contact with the oil drain 12 and the rear lid 14 with a predetermined tightening margin.

  As shown in FIGS. 1 and 2, the sealing device 30 includes a case 16, a metal ring 18, a cored bar 32, and a seal body 34.

  The case 16 has a metal three-stage cylindrical shape. The large-diameter cylindrical portion 16a is press-fitted into the inner peripheral surface of the bearing outer ring 2. The small-diameter cylindrical portion 16c forms a labyrinth seal with the annular recess of the rear lid 14 (or the oil drainer 12) as will be described later. A metal ring 18 is fitted to the medium diameter cylindrical portion 16b. The metal ring 18 has an inverted L-shaped cross section and includes a cylindrical portion and a disk portion, and is fitted to the medium diameter cylindrical portion 16b of the case 16 at the cylindrical portion. A metal core 32 having an inverted L-shaped cross section is fitted inside the metal ring 18, and the case 16, the metal ring 18, and the metal core 32 have a three-layer structure.

  A seal body 34 is fixed to a disk portion 33 extending in the radial direction of the core metal 32. The seal body 34 is made of a heat-resistant rubber material and includes a disk portion 36, a main lip 38, and a dust lip 40. The disk part 36 is integrally baked on the disk part 33 of the core metal 32. The main lip 38 extends substantially axially from the inner diameter end of the seal disc portion 36. A garter spring 28 is mounted on the outer periphery of the main lip 38. The dust lip 40 extends substantially axially from the inner diameter end of the seal disc portion 36 in the direction opposite to the main lip 38. The dust strip 40 has a substantially rectangular cross section, and a plurality of recesses 48 are formed in the inner peripheral surface 46. Reference numeral 39 denotes a cylindrical portion that connects the main lip 38 and the dust lip 40.

  As shown in FIGS. 1 and 2, the cylindrical portion 39 extends substantially in the axial direction in a state where it is assembled at a predetermined position, and an outer pressure chamber PB is formed on the outer diameter side, and an inner pressure chamber PC is formed on the inner diameter side. Is done. Grease is applied to the annular space between the main lip 38 and the dust lip 40, that is, the inner pressure chamber PC for lubricating the seal lip. To prevent the lubricant (grease) inside the bearing from flowing out, the difference between the outer diameter of the oil drainer 12 or the rear cover 14 (hereinafter, only the rear cover will be described for the sake of simplicity) and the inner diameter of the lip tip is shown. A predetermined tightening force is secured by the fitting force of the main lip 38 and the diameter reducing force of the garter spring 28.

  On the other hand, the dust strip 40 on the outside of the bearing forms a minute gap between the outer diameter of the rear lid 14 and the inner diameter of the lip tip. In this embodiment, an annular groove 14b is formed in a portion of the rear lid 14 facing the inner peripheral surface 46 of the dust lip 40. The annular groove 14b acts like a rain gutter. That is, even if water enters, it flows down through the annular groove 14b. Further, since the annular groove 14b portion and the dust lip 40 are not in contact with each other, there is no need for polishing, and the polishing thinning for the surface with which the main lip 38 contacts can be used as it is.

  The plurality of recesses 48 provided on the inner peripheral surface 46 of the dust lip 40 generate dynamic pressure as the axle 10 and the rear lid 14 rotate. As a result, intrusion of water or the like from the outside and leakage of grease inside the bearing are prevented at the same time. Further, since the recess 48 is provided in the inner peripheral surface 46 of the dust lip 40, dynamic pressure is generated with rotation, so that the gap between the inner peripheral surface 46 of the dust lip 40 and the outer peripheral surface of the rear lid 14 is increased. Clearance is secured. As a result, the inner pressure chamber PC does not enter a negative pressure state. Accordingly, the problem of adsorption of the dust lip 40 is solved.

  A thin portion 42 is formed in the disc portion 36 of the seal body 34 by providing a circular recess 37. For this purpose, a through hole is provided in the disk portion 33 of the cored bar 32. The thin portion 42 is provided with a slit 44 in one vertical character (see FIG. 2B). The slit 44 communicates the outer pressure chamber PB with the outside air, thereby releasing the positive pressure air and the negative pressure air in the outer pressure chamber PB into the atmosphere when the bearing is operated or stopped, and always maintaining the normal pressure. To do. This type of bearing is incorporated in a mechanical device so that the top-to-bottom direction is constant on the basis of the embossed seal on the seal surface that represents the manufacturer name and model number. Therefore, the thin-walled portion 42 is provided in association with these raised stamps so that the thin-walled portion 42 is positioned at 12:00 in the clockwise direction when assembled. By arranging the thin wall portion at the 12 o'clock position in the clockwise direction, there is no fear of water entering from the slit 44 even when used in an atmosphere where water falls or where water is dripping.

  A protrusion 50 is formed at the tip of the small diameter cylindrical portion 16c of the case 16 so as to protrude to the outer diameter side over the entire circumference. The inner peripheral surface of the small-diameter cylindrical portion 16c including the protrusion 50 is parallel to the axis, but the outer peripheral surface of the protrusion 50 is an inclined surface having a smaller diameter toward the end. On the other hand, the rear lid 14 has an annular recess 15 defined by inner wall surfaces 15a, 15b, 15c. The small-diameter cylindrical portion 16c and the protrusion 50 of the case 16 enter the annular recess 15 to form a labyrinth. Specifically, between the inner wall surface 15a of the annular recess 15 and the outer peripheral surface 52 of the projection 50, between the inner wall surface 15b of the annular recess 15 and the end surface of the projection 50, and the inner wall surface 15c of the annular recess 15 By forming a minute clearance between the inner peripheral surface of the small-diameter cylindrical portion 16c including the annular protrusion 50, the bent portion is bent between the rotating portion (for example, the back lid 14) and the stationary portion (for example, the case 16 and the protrusion 50). A small passage is made to reduce leakage. Further, as can be seen from FIG. 1, the clearance between the shoulder 16d of the case 16 and the end surface 14a of the back cover 14 and the space between the dust lip 40 and the end surface 14c of the back cover 14 are reduced to enhance the sealing effect. is there.

  The small-diameter cylindrical portion 16c of the case 16 extends in the axial direction from the small-diameter end of the shoulder portion 16d for positioning in the axial direction by applying the cored bar 32 of the seal body 34, but at the end of the small-diameter cylindrical portion 16c. By forming the protrusion 50, a groove 54 is formed between the protrusion 50 and the shoulder 16d over the entire circumference. Therefore, the protrusion 50 serves as a dike, and the water that has entered from above passes through the groove 54 and is discharged from the lower part. Further, the inner wall surface 15a of the recess 15 is an inclined surface having a large diameter on the opening side of the recess 15, and water and dust are easily discharged at the lower portion, and water or the like is difficult to enter due to the action of centrifugal force during rotation. It has a shape.

  FIG. 3 shows an embodiment in which ribs 56 extending in the circumferential direction are provided on the inner peripheral surface of the dust lip 40 in place of the recesses 48. Here, a case where three parallel ribs 56 are arranged in parallel is illustrated. Each rib 56 has a cut-out 58 in at least one place in the circumferential direction, and the ribs 56 are arranged out of phase so that the cut-outs 58 are not aligned. As a result, the flow resistance becomes larger than the state in which the cut-outs 58 are aligned, and it becomes difficult for foreign matter or the like to enter from the outside to flow in.

  In addition, the bearing with a sealing device of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

It is sectional drawing which shows embodiment of this invention, Comprising: It is a principal part enlarged view of FIG. A is an enlarged view of the sealing device of FIG. 1, and B is a view taken in the direction of arrow B in FIG. It is sectional drawing which shows another embodiment. It is a longitudinal cross-sectional view of a railway vehicle axle bearing. It is a longitudinal cross-sectional view of the bearing for railcar axles for demonstrating the prior art. It is a principal part enlarged view of FIG.

Explanation of symbols

2 Bearing outer ring 4 Bearing inner ring 6 Rolling element 8 Cage 10 Axle 12 Oil drain 14 Back cover 14a End face 14b Annular groove 15 Annular cavity 15a, 15b, 15c Inner wall 16 Case 16a Large diameter cylindrical part 16b Medium diameter cylindrical part 16c Small diameter Cylindrical part 16d Shoulder part 18 Metal ring 28 Garter spring 30 Sealing device 32 Core metal 33 Core metal disk part 34 Seal body 36 Seal body disk part 37 Recess 38 Main lip 39 Cylindrical part 40 Dustrip 42 Thin part 44 Slit 46 Da Inner circumferential surface of the strip 48 Recess 50 Protrusion 52 Outer circumferential surface 54 Groove 56 Rib 58 Cut through PA Bearing inner space PB Outer pressure chamber PC Inner pressure chamber

Claims (7)

  A railcar axle bearing sealing device having a rubber seal body, the seal body extending in a radial direction from a radially extending disk portion and an inner diameter end of the disk portion. A bearing for a railway vehicle axle comprising a main lip and a dust lip extending from an inner diameter end of the disk portion to the opposite side of the main lip, wherein the dust lip constitutes a non-contact seal. Sealing device.   2. The railcar axle bearing sealing device according to claim 1, wherein a labyrinth is formed between the inner peripheral surface of the dust lip and the rotating body.   The labyrinth is formed between the end face of the dust lip and the rotating body, and the sealing device for a railway vehicle axle bearing according to claim 1 or 2.   The apparatus for sealing a bearing for a railway vehicle axle according to claim 1 or 2, wherein a plurality of recesses arranged in a circumferential direction are provided on an inner peripheral surface of the dust lip.   In the inner peripheral surface of the dust lip, circumferentially extending ribs provided with cuts in at least one place in the circumferential direction are arranged in parallel and out of phase so that the cuts are not aligned with each other. The sealing device for a bearing for a railway vehicle axle according to any one of claims 1 to 4.   6. The sealing device for a railway vehicle axle bearing according to claim 1, wherein a protrusion protruding outward is provided on an end of the case over the entire circumference.   7. The sealing device for a railway vehicle axle bearing according to claim 6, wherein an annular recess for receiving the protrusion is provided in the rotating body, and a labyrinth is formed by the protrusion and the recess.