Axle bearing for railway vehicle

Abstract

A multi-row tapered roller bearing (20) for rotatably supporting an axle (50) of a railway vehicle comprises: an outer seal member (30) having an outer cylindrical part (31) attached to an inner diameter part (21b) of an outer ring (21), and a standing plate part (32) extending radially inward from a width-direction outer end of the outer cylindrical part (31); a small-diameter step part (26) formed in a large-diameter flange part (25) of an inner ring (23) adjacent to an inner diameter end (32a) of the standing plate part (32); and an annular recess (61) provided at an edge of the inner peripheral surface of a small-diameter flange part (27) of one inner ring (23), said edge being on an inner-diameter-side of an inner-ring small-end surface (27a). The inner diameter end (32a) of the standing plate part (32) adjacent to the outer periphery of the small-diameter step part (26) faces, in the axle direction, a side wall surface (26b) between the large-diameter flange part (25) and the small-diameter step part (26) of the inner ring (23).

Description

Railway vehicle axle bearings

[0001] The present invention relates to a railway vehicle axle bearing that rotatably supports the axle of a railway vehicle.

[0002] Typically, a railway vehicle bearing unit is attached to the end of a railway vehicle axle to rotatably support the axle and support the weight of the vehicle. This type of railway vehicle bearing unit generally includes a double-row tapered roller bearing (hereinafter simply referred to as a "bearing"), which is an example of a railway vehicle axle bearing, and the railway vehicle axle is supported by this bearing. This bearing includes a single outer ring and two inner rings, each divided into a separate row, and multiple tapered rollers held in a cage are rollably disposed between the two rows of raceway surfaces of the outer ring and the inner ring. Sealing devices (also called "seals") are disposed on both axial ends of this bearing.

[0003] Traditionally, bearings used in railway vehicle bogies are important parts, so they have been disassembled and inspected during regular vehicle inspections, and bearings that are found to be faulty have been reassembled and continued to be used. However, due to the impact of the decline in the productive labor force in society in recent years, there is a demand for extending the regular inspection intervals for railway vehicles and reducing maintenance. ２ From the perspective of contributing to the environment through reductions in energy consumption, railway vehicle axle bearings (hereinafter simply referred to as "axle bearings") are required to be lightweight and space-saving, along with improved reliability and longer life. Therefore, future axle bearings will need to be able to withstand high loads and maintain long-term lubrication, while also being lightweight, space-saving, and have improved maintainability that requires bearing disassembly, which will be added value.

[0004] Axle bearings, which support the wheelset (wheel and axle) of railway vehicles, support the weight of the vehicle and allow the wheels to rotate, and are subjected to high loads as well as vibrations while the vehicle is running. For this reason, many axle bearings are equipped with a sealing device that seals grease inside the bearing and retains the grease.

[0005] Patent Document 1 discloses a double-row tapered roller bearing in which annular recesses are provided on the edge along the inner ring small end face on the outer peripheral surface of the small rib portion (small diameter rib portion) of each inner ring, and an inner ring spacer is provided that fits across these annular recesses, thereby preventing the inner ring spacer from coming into direct contact with the surface of the shaft. This double-row tapered roller bearing can prevent scratches on the shaft due to rotation of the inner ring spacer and makes it easy to adjust the axial clearance.

[0006] Furthermore, Patent Document 2 discloses a railway vehicle bearing device in which the outer peripheral surface of the inner ring extending beyond the outer ring in the width direction is provided with a step portion into which a seal member can be dropped, thereby facilitating disassembly of the seal member. In this railway vehicle bearing device, the width of the inner ring, where the inner ring extension portion with which the seal member slides, extends, is greater than the width of the outer ring, and is therefore wider in the axial direction.

[0007] Furthermore, Patent Document 3 discloses a double-row tapered roller bearing in which a seal consisting of a seal plate, in which a seal member is integrally joined to a core metal fitted onto the inner periphery of the end of the outer ring, and a slinger fitted onto the outer diameter of the inner ring, is attached to the opening of the annular space formed between the outer ring and the inner ring. This seal has a compact structure with an assembled width equal to or less than the width of the inner ring, but it is configured with a large number of parts. Therefore, it is thought that disassembly of the seal member would be difficult.

[0008] Japanese Patent No. 5911688 Japanese Patent No. 4260935 Japanese Patent No. 4731508

[0009] However, in the double-row tapered roller bearing of Patent Document 1, an annular recess is provided on the outer peripheral surface of the inner ring to prevent stamping marks and adjust the clearance, rather than disassembling the inner ring, and there is no specific mention of disassembling the sealing device.

[0010] Furthermore, in the sealing device of Patent Document 2, it is difficult to make the width of the outer diameter portion of the seal case equal to or smaller than the width of the outer ring or the width of the inner ring in order to achieve compactness. Furthermore, in the railway vehicle bearing device of Patent Document 2, the width of the seal outer ring of the seal member is larger than the width of the inner ring, and compactness is not taken into consideration. Furthermore, since the step portion provided on the inner ring is configured to press the seal member, which has low rigidity, when the inner ring is disassembled, it is expected that the force required to pull out the inner ring will not be easily transmitted to the seal member, making disassembly difficult.

[0011] Furthermore, the double-row tapered roller bearing of Patent Document 3 does not take disassembly into consideration, and there is no location into which a disassembly tool can be inserted when disassembling the seal, making it difficult to disassemble it together with the inner ring.

[0012] Therefore, while the above-mentioned axle bearings with sealing devices have the same functions as conventional bearings, they have not been able to fully meet future needs such as improved maintainability, weight reduction, and space saving.

[0013] The present invention has been made in view of the above-mentioned problems, and its object is to provide an axle bearing for a railway vehicle that can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0014] The above object of the present invention can be achieved by the following configuration (1) or (2). (1) A railway vehicle axle bearing having an outer ring having double-row outer ring raceway surfaces, a pair of inner rings each having an inner ring raceway surface in one row, and two rows of rolling elements arranged to roll freely between the outer ring and the pair of inner rings, and rotatably supporting an axle having railway vehicle wheels attached to its end, the axle bearing comprising: an outer seal member having an outer cylindrical portion attached to the inner diameter portion of the outer ring and a standing plate portion extending radially inward from the widthwise outer end of the outer cylindrical portion; a small diameter step portion formed on a large diameter rib portion of the inner ring adjacent to the inner diameter end of the standing plate portion; and an annular recess provided on an edge portion of the inner peripheral surface of the small diameter rib portion of at least one of the inner rings, on the inner diameter side of the inner ring small end face, wherein the inner diameter end of the standing plate portion adjacent to the outer periphery of the small diameter step portion faces in the axle direction against a side wall surface between the large diameter rib portion of the inner ring and the small diameter step portion. (2) A railway vehicle axle bearing having an outer ring having double-row outer ring raceway surfaces, a pair of inner rings each having an inner ring raceway surface in one row, two rows of rolling elements arranged to roll freely between the outer ring and the pair of inner rings, and an inner ring spacer arranged between the pair of inner rings to adjust bearing clearance, which rotatably supports an axle having railway vehicle wheels attached to its end, the axle bearing comprising: an outer seal member having an outer cylindrical portion attached to the inner diameter portion of the outer ring and a standing plate portion extending radially inward from the outer end of the outer cylindrical portion in the width direction; a small-diameter stepped portion formed in a large-diameter rib portion of the inner ring adjacent to the inner diameter end of the standing plate portion; and an annular recess provided along the inner peripheral surface of the inner ring spacer, wherein the inner diameter end of the standing plate portion adjacent to the outer periphery of the small-diameter stepped portion faces a side wall surface between the large-diameter rib portion of the inner ring and the small-diameter stepped portion in the axle direction.

[0015] According to the railway vehicle axle bearing of the present invention, it is possible to improve reliability and extend life, as well as to improve maintainability, reduce weight, and save space.

[0016] FIG. 1 is a schematic cross-sectional view showing a railway vehicle bearing unit including a railway vehicle axle bearing according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing an enlarged view of portion A in FIG. 1. FIG. 3 is a schematic cross-sectional view showing an enlarged view of portion B in FIG. 1. FIG. 4 is a schematic cross-sectional view and an enlarged view of essential parts showing a railway vehicle bearing unit including a railway vehicle axle bearing according to a second embodiment of the present invention. FIG. 5 is a schematic cross-sectional view and an enlarged view of essential parts showing a railway vehicle bearing unit including a railway vehicle axle bearing according to a third embodiment of the present invention. FIG. 6 is a schematic cross-sectional view and an enlarged view of essential parts showing a railway vehicle bearing unit including a railway vehicle axle bearing according to a fourth embodiment of the present invention. FIG. 7 is a schematic cross-sectional view and an enlarged view of essential parts showing a railway vehicle bearing unit including a railway vehicle axle bearing according to a fifth embodiment of the present invention. FIG. 8 is a schematic cross-sectional view and an enlarged view of essential parts showing a railway vehicle bearing unit including a railway vehicle axle bearing according to a sixth embodiment of the present invention. Fig. 9 is a schematic cross-sectional view illustrating the disassembly procedure for the railway vehicle axle bearing shown in Fig. 8, showing the state in which the pressing piece of the disassembly tool is inserted into the annular recess provided between a pair of inner rings. Fig. 10 shows the state in which one of the inner rings shown in Fig. 9 is pressed by the pressing piece of the disassembly tool, and the side wall surface on the small-diameter step side of the large-diameter flange of the inner ring comes into contact with the upright portion of the outer seal member. Fig. 11 shows the state in which one of the inner rings shown in Fig. 10 is pressed by the pressing piece of the disassembly tool, and the outer cylindrical portion of the seal member pressed by the inner ring on one side is separated from the inner diameter portion of the outer ring. Fig. 12 is a schematic cross-sectional view illustrating an enlarged view of an outer seal member according to a modified example of the present invention.

[0017] Hereinafter, a railway vehicle axle bearing according to an embodiment of the present invention will be described in detail with reference to the drawings. (First Embodiment) Fig. 1 is a schematic cross-sectional view showing a railway vehicle bearing unit 10 including a railway vehicle axle bearing according to a first embodiment of the present invention. Figs. 2 and 3 are schematic cross-sectional views showing enlarged views of portions A and B in Fig. 1. As shown in Fig. 1, the railway vehicle bearing unit 10 of the first embodiment includes a double-row tapered roller bearing 20 as the railway vehicle axle bearing, and an axle 50 of the railway vehicle is rotatably supported by this double-row tapered roller bearing 20. A wheel (not shown) of the railway vehicle is attached to the outer end of the axle 50 (i.e., the portion with the larger axle diameter in Fig. 1).

[0018] The double-row tapered roller bearing 20 comprises a single outer ring 21 having double-row outer ring raceway surfaces 21a, a pair of inner rings 23, 23 each having an inner ring raceway surface 23a for each row, two rows of tapered rollers (rolling elements) 22 arranged to roll freely between the outer ring raceway surface 21a of the outer ring 21 and the two rows of inner ring raceway surfaces 23a of the pair of inner rings 23, 23, and a cage 24 that holds the plurality of tapered rollers 22. A grease supply port (not shown) is formed at an appropriate position in the axial center of the outer ring 21 for sealing grease (lubricant) within the bearing space.

[0019] Spacer rings 14 and rear cover 12 are arranged around axle 50 on both axial ends of inner rings 23, 23 so as to abut against the axial end faces of inner ring 23. Spacer ring 14, inner rings 23, 23, and rear cover 12 are sandwiched between outer peripheral surface step 51 of axle 50 and front cover 11, and are fixed with bolts 13 from the axial end 52 side of axle 50. Furthermore, outer ring 21 is positioned in the axial direction by being fixed to a housing (not shown).

[0020] As shown in Figure 1, an annular recess 61 is defined between the abutting inner ring small end faces 27a, 27a of a pair of inner rings 23, 23 arranged around the axle 50. As shown in Figure 2, the annular recess 61 according to the first embodiment is provided on an edge along the inner ring small end face 27a of the inner peripheral surface of the small diameter rib 27 of one of the inner rings 23 arranged on the outer peripheral surface step 51 side of the axle 50. That is, the annular recess 61 is formed by a notch 60 with a rectangular cross section cut out at a projecting corner between the inner peripheral surface of the small diameter rib 27 of one of the inner rings 23 and the inner ring small end face 27a.

[0021] Furthermore, sealing devices 29, 29 are provided on both sides of the double-row tapered roller bearing 20 according to this first embodiment, and these sealing devices 29, 29 prevent foreign matter from entering the double-row tapered roller bearing 20 and grease from leaking from inside the bearing.

[0022] 3, the sealing device 29 is composed of an outer seal member 30 attached to the outer ring 21, at least one small diameter step 26 formed on the large diameter flange 25 of the inner ring 23 adjacent to the inner diameter portion of the outer seal member 30, and an inner seal member 40 fixed to the small diameter step 26. This small diameter step 26 is formed on the large diameter flange 25 of the inner ring 23 closer to the end in the width direction (to the right in FIG. 3) than the inner ring raceway surface 23a.

[0023] The outer seal member 30 is formed from a metal material and has a U-shaped cross section, with the outer cylindrical portion 31 attached to the inner diameter portion 21b of the outer ring 21 closer to the widthwise end than the outer ring raceway surface 21a, a standing plate portion 32 extending radially inward from the widthwise outer end of the outer cylindrical portion 31, and an inner cylindrical portion 33 extending from the inner diameter end 32a of the standing plate portion 32 toward the inside of the bearing. The tip of the inner cylindrical portion 33 of the standing plate portion 32 faces, in the axial direction (left-right direction in FIG. 3 ), the side wall surface 26b between the large diameter flange 25 and the small diameter stepped portion 26 of the inner ring 23. In other words, the outer diameter dimension D2 of the large diameter flange 25 of the inner ring 23 is larger than the inner diameter dimension D1 of the outer seal member 30 of the sealing device 29.

[0024] Therefore, the outer seal member 30, which is formed with a U-shaped cross section, has a simple and compact shape in which the upright portion 32 extending radially inward from the outer end of the width direction of the outer cylindrical portion 31 attached to the inner surface of the inner diameter portion 21b of the outer ring 21 does not protrude beyond the outer ring end face of the outer ring 21.

[0025] An elastic body 35 is integrally provided and fixed to the inner diameter end 32a of the upright portion 32 and the inner cylindrical portion 33 of the outer seal member 30. This elastic body 35, together with the inner cylindrical portion 33, forms the inner diameter portion of the outer seal member 30. The elastic body 35 is made of an elastic seal material such as rubber or elastomer and integrally includes a first lip 36 and a second lip 37, as well as a third lip 38 and a fourth lip 39, which face the inner seal member 40 fixed to the small diameter step portion 26.

[0026] The inner seal member 40 is formed with a U-shaped cross section and includes an inner sleeve 41 that is press-fitted into the small-diameter step portion 26 of the inner ring 23, a flange 42 that extends radially outward from the outer widthwise end of the inner sleeve 41, and an outer sleeve 43 that extends from the inner diameter end of the flange 42 toward the inside of the bearing.

[0027] The first lip 36 of the elastic body 35 functions to prevent or reduce leakage of grease from the inside of the bearing to the atmosphere over the entire outer circumferential surface of the inner sleeve 41 of the inner seal member 40. The second lip 37 of the elastic body 35 functions to prevent or reduce intrusion of foreign matter from the atmosphere into the inside of the bearing over the entire outer circumferential surface of the inner sleeve 41 of the inner seal member 40.

[0028] Furthermore, by providing the inner seal member 40, with which the elastic body 35 can slide, on the outer peripheral surface 26a of the small diameter step portion 26 of the inner ring 23, the outer peripheral surface 26a of the small diameter step portion 26 is prevented from wearing out due to sliding contact with the elastic body 35. Furthermore, when the sealing function deteriorates, the initial sealing performance can be restored by replacing only the inner seal member 40.

[0029] The third lip 38 and fourth lip 39 of the elastic body 35 are disposed so as to sandwich the outer sleeve 43 of the inner seal member 40 in the radial direction, thereby forming a labyrinth seal.

[0030] Furthermore, as shown in Figure 3, the double-row tapered roller bearing 20 according to the first embodiment is configured so that the axial relative distance L1 between the outer surface 24a of the retainer 24, which holds the plurality of tapered rollers 22 rotatably, and the upright portion 32 of the outer seal member 30 is greater than the axial relative distance L2 between the side wall surface 26b between the large diameter flange portion 25 and the small diameter step portion 26 of the inner ring 23 and the upright portion 32 of the outer seal member 30.

[0031] Thus, with the double-row tapered roller bearing 20 according to the first embodiment described above, when disassembling the sealing device 29 for maintenance, the tip of the pressing piece 75 of the disassembly tool 70 (see FIG. 9 ) can be easily inserted into the annular recess 61 in one of the inner rings 23. Thus, the disassembly tool 70 moved axially can press the inner ring small end face 27a of the small diameter rib 27 in the other inner ring 23, which was arranged on the front cover 11 side, for example, axially outward.

[0032] Incidentally, in conventional double-row tapered roller bearings, it was necessary to increase the axial clearance between the sealing device and the inner ring large end face of the large diameter rib portion of the inner ring in order to ensure an axial clearance for inserting the pressing piece 75 of the disassembly tool 70, which reduced the degree of freedom in designing the sealing device and inner ring shape. In contrast, in the double-row tapered roller bearing 20 according to the first embodiment, an annular recess 61 for inserting the pressing piece 75 of the disassembly tool 70 is provided in one of the inner rings 23, so there is no need to move the inner ring 23 axially to ensure the tool insertion clearance, and the axial clearance between the side wall surface 26b (inner ring large end face) of the large diameter rib 25 of the inner ring 23 and the sealing device 29 can be reduced, thereby increasing the degree of freedom in designing the sealing device 29 and inner ring shape.

[0033] The inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30 adjacent to the outer periphery of the small-diameter stepped portion 26 of the inner ring 23 faces the side wall surface 26b between the large-diameter rib portion 25 and the small-diameter stepped portion 26 of the inner ring 23 in the axle direction, and the outer diameter dimension D2 of the large-diameter rib portion 25 of the inner ring 23 is larger than the inner diameter dimension D1 of the outer seal member 30. Therefore, the side wall surface 26b of the other inner ring 23, which has been moved axially relative to the outer ring 21, presses the inner cylindrical portion 33 of the outer seal member 30, making it possible to separate the outer seal member 30 from the outer ring 21. In other words, by configuring the sealing device 29 so that the inner ring 23 directly presses the outer seal member 30, the disassembly of the sealing device 29 can be improved. As a result, the maintainability of the double-row tapered roller bearing 20 is improved.

[0034] In this case, as described above, the axial relative distance L1 between the retainer 24 and the outer seal member 30 is greater than the axial relative distance L2 between the inner ring 23 and the outer seal member 30, so when the other inner ring 23 is moved axially outward relative to the outer ring 21, the outer seal member 30 will not come into contact with the retainer 24 inside the bearing before the side wall surface 26b of the inner ring 23.

[0035] That is, when the other inner ring 23 is moved axially outward relative to the outer ring 21, there is no concern that the outer seal member 30 and the cage 24 will come into contact, damaging or deforming the cage 24 and making it impossible to continue using the double-row tapered roller bearing 20. In particular, with a cage that uses a resin material, contact with the outer seal member 30 must be avoided at all costs, so the configuration of the double-row tapered roller bearing 20 according to the first embodiment is effective.

[0036] Furthermore, the outer seal member 30 and inner seal member 40 that constitute the sealing device 29 in this first embodiment, and the inner ring 23, can be configured with a simple shape having the same circumferential cross section. Also, compared to conventional structures, the sealing device 29 of the double-row tapered roller bearing 20 has a simple and compact shape, making it possible to reduce the space required for the housing that secures the outer ring 21 and to omit constituent parts. This makes it possible to reduce the weight of the railway vehicle bearing unit 10.

[0037] As described above, the double-row tapered roller bearing 20 according to the first embodiment can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0038] 4 is a schematic cross-sectional view showing a railway vehicle bearing unit 10A including a railway vehicle axle bearing according to a second embodiment of the present invention. In a double-row tapered roller bearing 20A as a railway vehicle axle bearing according to this second embodiment, the same components as those in the double-row tapered roller bearing 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0039] As shown in Figure 4, railway vehicle bearing unit 10A of the second embodiment includes a double-row tapered roller bearing 20A as a railway vehicle axle bearing, and railway vehicle axle 50 is rotatably supported by this double-row tapered roller bearing 20A. In double-row tapered roller bearing 20A according to the second embodiment, an annular recess 63 is defined between abutting inner ring small end faces 27a, 27a of a pair of inner rings 23A, 23A arranged around axle 50.

[0040] 4, the annular recess 63 according to the second embodiment is provided on the edge of the inner circumferential surface of each small diameter rib 27 of the pair of inner rings 23A, 23A, that is, on the inner diameter side of the inner ring small end face 27a. That is, the annular recess 63 is formed by a pair of cutouts 62, 62 having a rectangular cross section, which are cut out at the corner between the inner circumferential surface of the small diameter rib 27 of the pair of inner rings 23A, 23A and the inner ring small end face 27a.

[0041] Therefore, according to the double-row tapered roller bearing 20A according to the second embodiment described above, when disassembling the sealing device 29 for maintenance, the tip of the pressing piece 75 of the disassembly tool 70 (see FIG. 9 ) can be easily inserted into the annular recess 63 defined between the abutting inner ring small end faces 27a, 27a of the pair of inner rings 23A, 23A. Thus, the disassembly tool 70 moved in the axial direction can press the small diameter rib 27 of the other inner ring 23A, which is arranged on the front cover 11 side, for example, axially outward.

[0042] The inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30, which is adjacent to the outer periphery of the small-diameter stepped portion 26 of the inner ring 23A, faces the side wall surface 26b between the large-diameter rib portion 25 and the small-diameter stepped portion 26 of the inner ring 23A in the axle direction, and the outer diameter dimension D2 of the large-diameter rib portion 25 of the inner ring 23A is larger than the inner diameter dimension D1 of the outer seal member 30. Therefore, the side wall surface 26b of the other inner ring 23A, which is moved axially relative to the outer ring 21, presses the inner cylindrical portion 33 of the outer seal member 30, making it possible to separate the outer seal member 30 from the outer ring 21. In other words, by configuring the sealing device 29 so that the inner ring 23A directly presses the outer seal member 30, the disassembly of the sealing device 29 can be improved. As a result, the maintainability of the double-row tapered roller bearing 20A is improved.

[0043] Therefore, similar to the double-row tapered roller bearing 20 according to the first embodiment described above, the double-row tapered roller bearing 20A according to the second embodiment can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0044] 5 is a schematic cross-sectional view showing a railway vehicle bearing unit 10B including a railway vehicle axle bearing according to a third embodiment of the present invention. In a double-row tapered roller bearing 20B as a railway vehicle axle bearing according to this third embodiment, the same components as those in the double-row tapered roller bearing 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0045] As shown in Figure 5, a railway vehicle bearing unit 10B according to the third embodiment includes a double-row tapered roller bearing 20B as a railway vehicle axle bearing, and a railway vehicle axle 50 is rotatably supported by this double-row tapered roller bearing 20B. In the double-row tapered roller bearing 20B according to the third embodiment, an inner ring spacer 28B that adjusts the bearing clearance is arranged between a pair of inner rings 23B, 23B arranged around the axle 50. An annular recess 65 is defined between an inner ring small end face 27a of one of the inner rings 23B arranged around the axle 50 and the axial end face of the inner ring spacer 28B.

[0046] 5, the annular recess 65 according to the third embodiment is provided on an edge along the inner peripheral surface of one axial end face of the inner ring spacer 28B. That is, the annular recess 65 is formed by a notch 64 having a rectangular cross section that is cut out at a projecting corner between the inner peripheral surface and the axial end face of the inner ring spacer 28B that faces the small diameter flange 27 of one inner ring 23B.

[0047] Therefore, according to the double-row tapered roller bearing 20B according to the third embodiment described above, when disassembling the sealing device 29 for maintenance, the tip of the pressing piece 75 of the disassembly tool 70 (see FIG. 9 ) can be easily inserted into the annular recess 65 provided on the edge along the inner circumferential surface of one axial end face of the inner ring spacer 28B. Thus, the disassembly tool 70 moved in the axial direction can press the small diameter rib 27 of the other inner ring 23B, which is arranged on the front cover 11 side, axially outward, for example, via the inner ring spacer 28B.

[0048] The inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30, which is adjacent to the outer periphery of the small-diameter stepped portion 26 of the inner ring 23B, faces the side wall surface 26b between the large-diameter rib portion 25 and the small-diameter stepped portion 26 of the inner ring 23B in the axle direction, and the outer diameter dimension D2 of the large-diameter rib portion 25 of the inner ring 23B is larger than the inner diameter dimension D1 of the outer seal member 30. Therefore, the side wall surface 26b of the other inner ring 23B, which is moved axially relative to the outer ring 21, presses the inner cylindrical portion 33 of the outer seal member 30, making it possible to separate the outer seal member 30 from the outer ring 21. In other words, by configuring the sealing device 29 so that the inner ring 23B directly presses the outer seal member 30, the disassembly of the sealing device 29 can be improved. As a result, the maintainability of the double-row tapered roller bearing 20B is improved.

[0049] Therefore, similar to the double-row tapered roller bearing 20 according to the first embodiment described above, the double-row tapered roller bearing 20B according to this third embodiment can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0050] 6 is a schematic cross-sectional view showing a railway vehicle bearing unit 10C including a railway vehicle axle bearing according to a fourth embodiment of the present invention. In a double-row tapered roller bearing 20C as a railway vehicle axle bearing according to this fourth embodiment, the same components as those in the double-row tapered roller bearing 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0051] As shown in Figure 6, a railway vehicle bearing unit 10C of the fourth embodiment includes a double-row tapered roller bearing 20C as a railway vehicle axle bearing, and an axle 50 of the railway vehicle is rotatably supported by this double-row tapered roller bearing 20C. In the double-row tapered roller bearing 20C according to the fourth embodiment, an inner ring spacer 28C that adjusts the bearing clearance is arranged between a pair of inner rings 23C, 23C arranged around the axle 50. An annular recess 66 is defined by the inner ring spacer 28C between the opposing inner ring small end faces 27a, 27a of the pair of inner rings 23C, 23C arranged around the axle 50.

[0052] 6, the annular recess 66 according to the fourth embodiment is provided on the inner peripheral surface of the inner ring spacer 28 disposed between the pair of inner rings 23C, 23C. That is, the annular recess 66 is formed by making the inner peripheral surface of the inner ring spacer 28C larger in diameter than the inner peripheral surface of the inner ring 23C, and by holding the wide portion of the inner ring spacer 28C, which has a T-shaped cross section, against the outer peripheral surfaces of the small diameter flanges 27 of the pair of inner rings 23C, 23C.

[0053] Therefore, according to the double-row tapered roller bearing 20C according to the fourth embodiment described above, when disassembling the sealing device 29 for maintenance, the tip of the pressing piece 75 of the disassembly tool 70 (see FIG. 9 ) can be easily inserted into the annular recess 66 provided on the inner peripheral surface of the inner ring spacer 28C. Thus, the disassembly tool 70 moved axially can press the inner ring small end face 27a of the other inner ring 23B that is arranged on the front cover 11 side, for example, axially outward.

[0054] The inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30, which is adjacent to the outer periphery of the small-diameter stepped portion 26 of the inner ring 23C, faces the side wall surface 26b between the large-diameter rib portion 25 and the small-diameter stepped portion 26 of the inner ring 23C in the axle direction, and the outer diameter dimension D2 of the large-diameter rib portion 25 of the inner ring 23C is larger than the inner diameter dimension D1 of the outer seal member 30. Therefore, the side wall surface 26b of the other inner ring 23C, which is moved axially relative to the outer ring 21, presses the inner cylindrical portion 33 of the outer seal member 30, making it possible to separate the outer seal member 30 from the outer ring 21. In other words, by configuring the sealing device 29 so that the inner ring 23C directly presses the outer seal member 30, the disassembly of the sealing device 29 can be improved. As a result, the maintainability of the double-row tapered roller bearing 20C is improved.

[0055] Therefore, similar to the double-row tapered roller bearing 20 according to the first embodiment described above, the double-row tapered roller bearing 20C according to the fourth embodiment can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0056] 7 is a schematic cross-sectional view showing a railway vehicle bearing unit 10D including a railway vehicle axle bearing according to a fifth embodiment of the present invention. In a double-row tapered roller bearing 20D as a railway vehicle axle bearing according to the fifth embodiment, the same components as those in the double-row tapered roller bearing 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0057] As shown in Figure 7, a railway vehicle bearing unit 10D of the fifth embodiment includes a double-row tapered roller bearing 20D as a railway vehicle axle bearing, and a railway vehicle axle 50 is rotatably supported by this double-row tapered roller bearing 20D. In the double-row tapered roller bearing 20D of the fifth embodiment, an inner ring spacer 28D that adjusts the bearing clearance is arranged between a pair of inner rings 23D, 23D arranged around the axle 50. An annular recess 68 is formed in the inner peripheral surface of the inner ring spacer 28D.

[0058] 7, the annular recess 68 according to the fifth embodiment is provided in the inner peripheral surface of the inner ring spacer 28D that is disposed between the pair of inner rings 23C, 23C. That is, the annular recess 68 is formed by a notch portion 67 that has a rectangular cross section and is cut out into the inner peripheral surface of the inner ring spacer 28D.

[0059] Therefore, according to the double-row tapered roller bearing 20D according to the fifth embodiment described above, when disassembling the sealing device 29 for maintenance, the tip of the pressing piece 75 of the disassembly tool 70 (see FIG. 9 ) can be easily inserted into the annular recess 68 provided in the inner circumferential surface of the inner ring spacer 28D. Thus, the disassembly tool 70 moved in the axial direction can press the inner ring small end face 27a of the other inner ring 23D that was arranged on the front cover 11 side, for example, via the inner ring spacer 28D, axially outward.

[0060] The inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30, which is adjacent to the outer periphery of the small-diameter stepped portion 26 of the inner ring 23D, faces the side wall surface 26b between the large-diameter rib portion 25 and the small-diameter stepped portion 26 of the inner ring 23D in the axle direction, and the outer diameter dimension D2 of the large-diameter rib portion 25 of the inner ring 23D is larger than the inner diameter dimension D1 of the outer seal member 30. Therefore, the side wall surface 26b of the other inner ring 23D, which is moved axially relative to the outer ring 21, presses the inner cylindrical portion 33 of the outer seal member 30, making it possible to separate the outer seal member 30 from the outer ring 21. In other words, by configuring the sealing device 29 so that the inner ring 23D directly presses the outer seal member 30, the disassembly of the sealing device 29 can be improved. As a result, the maintainability of the double-row tapered roller bearing 20D is improved.

[0061] Therefore, similar to the double-row tapered roller bearing 20 according to the first embodiment described above, the double-row tapered roller bearing 20D according to the fifth embodiment can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0062] 8 is a schematic cross-sectional view showing a railway vehicle bearing unit 10E including a railway vehicle axle bearing according to a sixth embodiment of the present invention. In a double-row tapered roller bearing 20E as a railway vehicle axle bearing according to this sixth embodiment, the same components as those in the double-row tapered roller bearing 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0063] As shown in Figure 8, a railway vehicle bearing unit 10E according to the sixth embodiment includes a double-row tapered roller bearing 20E as a railway vehicle axle bearing, and an axle 50 of the railway vehicle is rotatably supported by this double-row tapered roller bearing 20E. In the double-row tapered roller bearing 20E according to the sixth embodiment, an inner ring spacer 28E that adjusts the bearing clearance is arranged between a pair of inner rings 23B, 23B arranged around the axle 50. An annular recess 69 is defined between an inner ring small end face 27a of one of the inner rings 23E arranged around the axle 50 and the axial end face of the inner ring spacer 28E.

[0064] 8, the annular recess 69 according to the sixth embodiment is provided on an edge portion along the inner circumferential surface of one axial end face of the inner ring spacer 28E, and on an edge portion along the inner ring small end face 27a of the inner circumferential surface of the small diameter rib 27 of one inner ring 23E. That is, the annular recess 69 is formed by a notch 62 having a rectangular cross section cut out and formed in a projected corner between the inner circumferential surface of the small diameter rib 27 of one inner ring 23E and the inner ring small end face 27a, and a notch 64 having a rectangular cross section cut out and formed in a projected corner between the inner circumferential surface and the axial end face of the inner ring spacer 28E facing the small diameter rib 27 of one inner ring 23E.

[0065] Therefore, with the double-row tapered roller bearing 20E according to the sixth embodiment described above, when disassembling the sealing device 29 for maintenance, the tip of the pressing piece 75 of the disassembly tool 70 (see FIG. 9 ) can be easily inserted into the annular recess 69 provided between the inner ring small end face 27a of one inner ring 23E and the axial end face of the inner ring spacer 28E. Thus, the disassembly tool 70 moved axially can press the small diameter rib 27 of the other inner ring 23B, which is arranged on the front cover 11 side, axially outward, for example, via the inner ring spacer 28E.

[0066] The inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30, which is adjacent to the outer periphery of the small-diameter stepped portion 26 of the inner ring 23E, faces the side wall surface 26b between the large-diameter rib portion 25 and the small-diameter stepped portion 26 of the inner ring 23E in the axle direction, and the outer diameter dimension D2 of the large-diameter rib portion 25 of the inner ring 23E is larger than the inner diameter dimension D1 of the outer seal member 30. Therefore, the side wall surface 26b of the other inner ring 23E, which is moved axially relative to the outer ring 21, presses the inner cylindrical portion 33 of the outer seal member 30, making it possible to separate the outer seal member 30 from the outer ring 21. In other words, by configuring the sealing device 29 so that the inner ring 23E directly presses the outer seal member 30, the disassembly of the sealing device 29 can be improved. As a result, the maintainability of the double-row tapered roller bearing 20E is improved.

[0067] Therefore, similar to the double-row tapered roller bearing 20 according to the first embodiment described above, the double-row tapered roller bearing 20E according to the sixth embodiment can improve reliability and extend life, as well as improve maintainability, reduce weight, and save space.

[0068] Here, an example of a disassembly method will be described using the double-row tapered roller bearing 20E according to the sixth embodiment described above as an example. Figures 9 to 11 are schematic cross-sectional views illustrating the disassembly procedure for the double-row tapered roller bearing 20E shown in Figure 8. As shown in Figure 9, for example, when disassembling the sealing device 29 of the double-row tapered roller bearing 20E, first, the double-row tapered roller bearing 20E is placed on a jig stand 80 placed on a workbench 90, with one axial end of the double-row tapered roller bearing 20E facing downward. The jig stand 80 is formed in an annular shape with an outer diameter slightly larger than the outer diameter of the outer ring 21, and an inner diameter slightly larger than the inner diameter of the inner diameter portion 21b of the outer ring 21.

[0069] The disassembly tool 70 has a drive shaft 71 that can be driven up and down, a disk-shaped tool body 73 attached to the lower end of the drive shaft 71, and a plurality of pressing pieces 75 that are housed in the tool body 73 and whose tips can be freely moved radially outward and inward from the outer peripheral surface of the tool body 73.

[0070] The tool body 73 has an outer diameter slightly smaller than the inner diameter of the inner ring 23E. Therefore, when the tips of the multiple pressing pieces 75 are all submerged within the tool body 73, the tool body 73 can be inserted through the inner ring 23E. On the other hand, when the tips of the multiple pressing pieces 75 protrude radially from the outer circumferential surface of the tool body 73, the tips of the pressing pieces 75 abut against the axial ends of the inner ring 23E, preventing the tool body 73 from being inserted through the inner ring 23E.

[0071] Then, double-row tapered roller bearing 20E is placed on jig stand 80 so that one axial end of outer ring 21 faces the upper edge of jig stand 80. At this time, it is not necessary to space two inner rings 23E, 23E apart in the axial direction in advance for double-row tapered roller bearing 20E to be placed on jig stand 80, so that pressing piece 75 of disassembly tool 70 can be inserted between inner ring 23E and inner ring spacer 28E.

[0072] Next, the drive shaft 71 of the disassembly tool 70 is driven downward, and the tool body 73, with the tips of the multiple pressing pieces 75 all submerged within the tool body 73, is inserted into the upper inner ring 23E. When the drive shaft 71 is moved downward relative to the tool body 73 at a position where the pressing pieces 75 and the annular recess 69 are aligned, the tips of the multiple pressing pieces 75 protrude radially from the outer peripheral surface of the tool body 73 that has penetrated the upper inner ring 23E, as shown in FIG. 9 , and are positioned within the annular recess 69 defined between the inner ring small end face 27a of the lower inner ring 23E and the axial end face of the inner ring spacer 28E. The tips of the multiple pressing pieces 75 of the disassembly tool 70 then abut against the axial end faces of the notches 62 in the lower inner ring 23E, allowing the axial end of the lower inner ring 23E to be pressed downward.

[0073] Then, when the drive shaft 71 of the disassembly tool 70 is driven downward, as shown in Figure 10, the side wall surface 26b on the small diameter step portion 26 side of the large diameter flange portion 25 of the lower inner ring 23E, which has moved downward relative to the outer ring 21 supported on the jig table 80, comes into contact with the inner cylindrical portion 33 of the outer seal member 30.

[0074] Furthermore, when the drive shaft 71 of the disassembly tool 70 is driven downward, the side wall surface 26b of the lower inner ring 23E presses downward the inner cylindrical portion 33 of the upright portion 32 of the outer seal member 30, so that the pressed outer cylindrical portion 31 of the outer seal member 30 is separated from the inner diameter portion 21b of the outer ring 21, as shown in Figure 11.

[0075] The present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate. Furthermore, the material, shape, dimensions, number, and location of each component in the above-described embodiments are arbitrary and not limited as long as they can achieve the present invention. For example, in the above-described embodiments, the outer seal member 30 is used as the outer seal member constituting the sealing device, but this is not limiting, and various outer seal members can be used.

[0076] 12 is an enlarged schematic cross-sectional view of an outer seal member 30F according to a modified example of the present invention. In a double-row tapered roller bearing 20F as an axle bearing for a railway vehicle equipped with an outer seal member 30F according to this modified example, the same components as those in the double-row tapered roller bearing 20 according to the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0077] 12, an outer seal member 30F according to a modified example is formed from a metal material and has an L-shaped cross section, with an outer cylindrical portion 31 attached to the inner diameter portion 21b of the outer ring 21 closer to the widthwise end than the outer ring raceway surface 21a, and a standing plate portion 32 extending radially inward from the widthwise outer end of the outer cylindrical portion 31. The inner diameter end 32a of this standing plate portion 32 faces the side wall surface 26b between the large diameter flange 25 and the small diameter stepped portion 26 of the inner ring 23 in the axle direction (the left-right direction in FIG. 12).

[0078] Therefore, the outer seal member 30F, which is formed with an L-shaped cross section, has a simple and compact shape in which the upright portion 32 extending radially inward from the widthwise outer end of the outer cylindrical portion 31 attached to the inner peripheral surface of the inner diameter portion 21b of the outer ring 21 does not protrude beyond the outer ring end face of the outer ring 21.

[0079] An elastic body 35F is integrally provided and fixed to the inner diameter end 32a of the outer seal member 30F, facing the outer periphery of the small diameter stepped portion 26 of the inner ring 23. This elastic body 35F, together with the inner diameter end 32a of the standing plate portion 32, forms the inner diameter portion of the outer seal member 30F. The elastic body 35F, which is made of an elastic seal material such as rubber or elastomer, integrally includes a first lip 36 and a second lip 37, as well as a third lip 38 and a fourth lip 39, which serve as lip portions that slidably contact the inner seal member 40 fixed to the small diameter stepped portion 26.

[0080] The first lip 36 of the elastic body 35F is in slidable contact over the entire circumference with the outer circumferential surface of the inner sleeve 41 of the inner seal member 40, and has the function of mainly preventing or reducing leakage of grease from the inside of the bearing to the atmosphere. The second lip 37 of the elastic body 35 is in slidable contact over the entire circumference with the outer circumferential surface of the inner sleeve 41 of the inner seal member 40, and has the function of mainly preventing or reducing intrusion of foreign matter from the atmosphere into the inside of the bearing.

[0081] As with the double-row tapered roller bearing 20 according to the first embodiment described above, the double-row tapered roller bearing 20F is capable of separating the outer seal member 30F from the outer ring 21 by the side wall surface 26b of the inner ring 23 being moved axially relative to the outer ring 21 and pressing the inner diameter end 32a of the outer seal member 30F.

[0082] Here, the features of the above-described embodiment of the railway vehicle axle bearing according to the present invention will be briefly summarized and listed below in [1] to [4]. [1] A railway vehicle axle bearing (double row tapered roller bearing 20, 20A) having an outer ring (21) having a double row outer ring raceway surface (21a), a pair of inner rings (23, 23, 23A, 23A) each having a row of inner ring raceway surfaces (23a), and two rows of rolling elements (tapered rollers 22) arranged to roll freely between the outer ring (21) and the pair of inner rings (23, 23, 23A, 23A), and rotatably supporting an axle (50) having a railway vehicle wheel attached to an end thereof, the axle bearing comprising: an outer ring (21) having a double row outer ring raceway surface (21a), a pair of inner rings (23, 23, 23A, 23A) each having a row of inner ring raceway surfaces (23a), and two rows of rolling elements (tapered rollers 22) arranged to roll freely between the outer ring (21) and the pair of inner rings (23, 23, 23A, 23A), the axle bearing comprising: an outer seal member (30, 30F) having an outer cylindrical portion (31) attached to the inner diameter portion (21b) of the outer ring (21), and a standing plate portion (32) extending radially inward from the widthwise outer end of the outer cylindrical portion (31); a small diameter step portion (26) formed on a large diameter rib portion (25) of the inner ring (23, 23A) adjacent to an inner diameter end (32a) of the standing portion (32); and an annular recess (61, 63) provided on an edge portion of the inner peripheral surface of the small diameter rib portion (27) of at least one of the inner rings (23, 23A), on an inner diameter side edge portion of an inner ring small end face (27a), wherein the inner diameter end (32a) of the standing portion (32) adjacent to the outer periphery of the small diameter step portion (26) faces a side wall surface (26b) between the large diameter rib portion (25) and the small diameter step portion (26) of the inner ring (23, 23A) in the axle direction.

[0083] According to the configuration [1] above, when disassembling the outer seal member (30, 30F), the tip of the pressing piece (75) of the disassembly tool (70) can be easily inserted into the annular recess (61, 63) of at least one of the inner rings (23, 23A). Thus, the disassembly tool (70), when moved axially, can push the small-diameter flange (27) of one of the inner rings (23, 23A) axially outward. Then, the side wall surface (26b) of the inner ring (23, 23A), which has been moved axially relative to the outer ring (21), presses the inner diameter end (32a) of the outer seal member (30, 30F), thereby enabling the outer seal member (30, 30F) to be separated from the outer ring (21). In other words, by configuring the outer seal member (30, 30F) so that the inner ring (23, 23A) directly presses against it, the disassembly of the sealing device (29) can be improved. As a result, the maintainability of the railway vehicle axle bearing (double-row tapered roller bearings 20, 20A) is improved.

[0084] [2] An outer ring (21) having a double row of outer ring raceway surfaces (21a), a pair of inner rings (23B, 23B, 23C, 23C, 23D, 23D, 23E, 23E) each having an inner ring raceway surface (23a) of each row, and two rows of rolling elements (tapered rollers 2) arranged freely to roll between the outer ring (21) and the pair of inner rings (23B, 23B, 23C, 23C, 23D, 23D, 23E, 23E). 2) and inner ring spacers (28B, 28C, 28D, 28E) that are disposed between the pair of inner rings (23B, 23B, 23C, 23C, 23D, 23D, 23E, 23E) and adjust a bearing clearance, and the axle bearing (double row tapered roller bearings 20B, 20C, 20D, 20E) rotatably supports an axle (50) having a wheel of the railway vehicle attached to an end thereof, an outer seal member (30, 30F) having an outer cylindrical portion (31) attached to an inner diameter portion (21b) of the outer ring (21) and a standing plate portion (32) extending radially inward from an outer end of the outer cylindrical portion (31) in a width direction; a small diameter step portion (26) formed on a large diameter flange portion (25) of the inner ring (23B, 23B, 23C, 23C, 23D, 23D, 23E, 23E) adjacent to an inner diameter end (32a) of the standing plate portion (32); and annular recesses (65, 66, 68, 69) provided along an inner peripheral surface of the inner ring spacer (28B, 28C, 28D, 28E), an inner diameter end (32a) of the standing plate portion (32) adjacent to the outer periphery of the small diameter step portion (26) faces in the axle direction a side wall surface (26b) between the large diameter flange portion (25) of the inner ring (23B, 23B, 23C, 23C, 23D, 23D, 23E, 23E) and the small diameter step portion (26).

[0085] According to the configuration [2] above, when disassembling the outer seal member (30, 30F), the tip of the pressing piece (75) of the disassembly tool (70) can be easily inserted into the annular recesses (65, 66, 68, 69) provided along the inner peripheral surface of the inner ring spacer (28B, 28C, 28D, 28E). Thus, the disassembly tool (70) moved axially can push the small-diameter flange (27) of one of the inner rings (23B, 23C, 23D, 23E) axially outward. Then, the side wall surface (26b) of the inner ring (23B, 23C, 23D, 23E) moved axially relative to the outer ring (21) pushes the inner diameter end (32a) of the outer seal member (30, 30F), thereby separating the outer seal member (30, 30F) from the outer ring (21). That is, by adopting a structure in which the inner ring (23B, 23C, 23D, 23E) directly presses the outer seal member (30, 30F), the sealing device can be easily disassembled, thereby improving the maintainability of the railway vehicle axle bearing (double-row tapered roller bearings 20B, 20C, 20D, 20E).

[0086] [3] The railway vehicle axle bearing (double-row tapered roller bearing 20, 20A, 20B, 20C, 20D, 20E) according to above [1] or [2], wherein a relative axial distance (L1) between each cage (24) that rotatably holds each of the two rows of rolling elements (tapered rollers 22) and the outer seal member (30, 30F) is greater than a relative axial distance (L2) between a side wall surface (26b) between the large-diameter rib portion (25) and the small-diameter step portion (26) of the inner ring (23, 23, 23A, 23A, 23B, 23B, 23C, 23C, 23D, 23D, 23E, 23E) and the outer seal member (30, 30F).

[0087] According to the configuration [3] above, when the inner ring (23, 23A, 23B, 23C, 23D, 23E) is moved axially relative to the outer ring (21), the outer seal member (30, 30F) does not come into contact with the retainer (24) inside the bearing before the side wall surface (26b) of the inner ring (23, 23A, 23B, 23C, 23D, 23E) comes into contact with the retainer (24) inside the bearing. Therefore, there is no concern that the retainer (24) will be damaged or deformed, rendering the railway vehicle axle bearing (double-row tapered roller bearing 20, 20A, 20B, 20C, 20D, 20E) unable to continue using.

[0088] [4] The railway vehicle axle bearing (double-row tapered roller bearing 20, 20A, 20B, 20C, 20D, 20E) according to [1] or [2] above, wherein the outer seal member (30) is formed with a U-shaped cross section having an inner cylindrical portion (33) extending from the inner diameter end (32a) of the upright portion (32) toward the inside of the bearing.

[0089] According to the configuration [4] above, the outer seal member (30) has increased annular rigidity and is less likely to deform even when pressed by the side wall surface (26b) of the inner ring (23, 23A, 23B, 23C, 23D, 23E), facilitating appropriate disassembly work.

[0090] This application is based on a Japanese patent application (Patent Application No. 2024-101167) filed on June 24, 2024, the contents of which are incorporated herein by reference.

[0091] The railway vehicle axle bearing according to the present invention has the functionality of a conventional bearing, while being able to fully meet future needs such as improved maintainability, weight reduction, and space saving.

[0092] REFERENCE SIGNS LIST 10 Railway vehicle bearing unit 20 Double-row tapered roller bearing (railway vehicle axle bearing) 21 Outer ring 21a Outer ring raceway surface 21b Inner diameter portion 22 Tapered roller (rolling element) 23 Inner ring 23a Inner ring raceway surface 25 Large diameter flange portion 26 Small diameter stepped portion 26b Side wall surface 27 Small diameter flange portion 30 Outer seal member 31 Outer cylindrical portion 32 Standing plate portion 32a Inner diameter end 50 Axle

Claims

1. A railway vehicle axle bearing having an outer ring having double-row outer ring raceway surfaces, a pair of inner rings each having an inner ring raceway surface in one row, and two rows of rolling elements arranged to roll freely between the outer ring and the pair of inner rings, and rotatably supporting an axle with railway vehicle wheels attached to its end, comprising: an outer seal member having an outer cylindrical portion attached to the inner diameter portion of the outer ring and a standing plate portion extending radially inward from the widthwise outer end of the outer cylindrical portion; a small diameter step portion formed on the large diameter rib portion of the inner ring adjacent to the inner diameter end of the standing plate portion; and an annular recess provided on the edge of the inner peripheral surface of the small diameter rib portion of at least one of the inner rings, on the inner diameter side of the inner ring small end face, wherein the inner diameter end of the standing plate portion adjacent to the outer periphery of the small diameter step portion faces in the axial direction of the axle against a side wall surface between the large diameter rib portion of the inner ring and the small diameter step portion.

2. A railway vehicle axle bearing comprising an outer ring having double-row outer ring raceway surfaces, a pair of inner rings each having an inner ring raceway surface in one row, two rows of rolling elements arranged to roll freely between the outer ring and the pair of inner rings, and an inner ring spacer arranged between the pair of inner rings to adjust the bearing clearance, which rotatably supports an axle having railway vehicle wheels attached to its end, the axle bearing comprising: an outer seal member having an outer cylindrical portion attached to the inner diameter portion of the outer ring and a standing plate portion extending radially inward from the outer end of the outer cylindrical portion in the width direction; a small-diameter stepped portion formed in the large-diameter rib portion of the inner ring adjacent to the inner diameter end of the standing plate portion; and an annular recess provided along the inner peripheral surface of the inner ring spacer, wherein the inner diameter end of the standing plate portion adjacent to the outer periphery of the small-diameter stepped portion faces, in the axle direction, a side wall surface between the large-diameter rib portion of the inner ring and the small-diameter stepped portion.

3. A railway vehicle axle bearing as set forth in claim 1 or 2, wherein the relative axial distance between the outer surface of each cage, which rotatably holds the two rows of rolling elements, and the outer seal member is greater than the relative axial distance between the side wall surface between the large diameter rib portion and the small diameter step portion of the inner ring and the outer seal member.

4. A railway vehicle axle bearing as set forth in claim 1 or 2, wherein the outer seal member is formed with a U-shaped cross section, with an inner cylindrical portion extending from the inner diameter end of the upright portion toward the inside of the bearing.

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