Rolling bearing device

Abstract

A rolling bearing device according to the present invention comprises: an inner race 11 that rotates integrally with a spool-type roll 3; an outer race 15; a plurality of rollers 13; a labyrinth ring 31 that is attached to a bearing box 17; and packing 32 that is in sliding contact with the labyrinth ring 31. The packing 32 is installed in a first seal groove 71 that is provided in the outer circumference of the inner race 11. The first seal groove 71 has a first side surface 66, a second side surface 67, and a groove bottom surface 68. The packing 32 has a cylindrical part 40 that is in sliding contact with the labyrinth ring 31, a biasing part 41 that is provided on the inside of the cylindrical part 40 in the radial direction and can elastically deform, a first protruding part 46 that is in continuous contact with the first side surface 71 in the circumferential direction, and a second protruding part 47 that is in continuous contact with the second side surface 72 in the circumferential direction. The biasing part 41 has a plurality of contact parts 42 that are intermittently provided along the circumferential direction and contact the groove bottom surface 68.

Description

Rolling bearing device

[0001] The present disclosure relates to a rolling bearing device.

[0002] Patent Document 1 discloses a rolling bearing device including a pestle-type roll used in a continuous casting machine. The pestle-type roll has a small diameter shaft portion and two large diameter portions having a diameter larger than that of the small diameter shaft portion. Since an inner ring of the rolling bearing device is attached to the small diameter shaft portion, the rolling bearing device has a two-split structure.

[0003] In the case of a continuous casting machine, cooling water, casting scale, and the like fall onto the rolling bearing device. To prevent the cooling water and casting scale from entering the interior of the bearing where the rollers of the rolling bearing device are present, a labyrinth ring, a packing, and an oil seal are used in the rolling bearing device. In the case of the rolling bearing device disclosed in Patent Document 1, the labyrinth ring is attached to the axle box, and the packing and the oil seal are attached to the inner ring. The packing and the oil seal come into contact with the labyrinth ring.

[0004] JP 2017-190835 A

[0005] The rolling bearing device is installed on the common base plate of the casting machine segments after the pestle-shaped roll is assembled to the axle box and rolling bearings. During this process, assembly errors may occur, and each part of the rolling bearing device may bend due to the heat and load of the slab during casting. Therefore, the interference at each circumferential position of the packing may vary. Therefore, as shown in FIG. 8 , the packing 90 includes a resin tubular portion 91 and a rubber biasing portion 92 to provide conformance with the labyrinth ring 100. The resin tubular portion 91 is in sliding contact with the labyrinth ring 100. The rubber biasing portion 92 is continuously provided along the inner circumference of the tubular portion 91. The biasing portion 92 has a protrusion 93 that contacts the groove bottom surface 96 of the seal groove 95. The packing 90 provides conformance primarily through elastic deformation of the protrusion 93.

[0006] After the rolling bearing device has been used for a long period of time, if the biasing portion 91 is significantly compressed in the radial direction, for example, in a portion of the circumferential direction, the protrusion 93 may become bent, as shown by the two-dot chain line in Figure 8. In this case, the packing 90 may not be able to exhibit sufficient followability. If the followability decreases, the interference of the packing 90 with the labyrinth ring 100 decreases, and the sealing performance between the packing 90 and the labyrinth ring 100 decreases.

[0007] Therefore, an object of the present disclosure is to provide a rolling bearing device equipped with a packing that can improve tracking performance.

[0008] a rolling bearing device according to the present disclosure comprising: a pestle-type roll; an axle box; an inner ring which rotates integrally with the pestle-type roll and has an inner ring raceway; an outer ring which has an outer ring raceway facing the inner ring raceway and is attached to the axle box; a plurality of rollers which are arranged between the inner ring raceway and the outer ring raceway; a labyrinth ring which is attached to the axle box so as to face radially an end of the inner ring in the axial direction; a packing which is attached to the inner ring and makes sliding contact with the labyrinth ring; and an oil seal which is attached to the inner ring and makes sliding contact with the labyrinth ring; The first seal groove has a first annular side surface, a second annular side surface axially opposite the first side surface, and a groove bottom surface provided between the first side surface and the second side surface, and the packing has: a cylindrical portion in sliding contact with the labyrinth ring; an elastically deformable biasing portion provided radially inside the cylindrical portion; a first protrusion in continuous circumferential contact with the first side surface; and a second protrusion in continuous circumferential contact with the second side surface, and the biasing portion has a plurality of contact portions that are provided intermittently along the circumferential direction and contact the groove bottom surface.

[0009] According to the rolling bearing device of the present disclosure, the ability of the packing to follow the labyrinth ring is improved.

[0010] FIG. 1 is a cross-sectional view showing an example of a rolling bearing device. FIG. 2 is a cross-sectional view showing a part of the first axial side of the rolling bearing device shown in FIG. 1. FIG. 3 is a cross-sectional view explaining a packing and a first seal groove. FIG. 4 is a cross-sectional view of the packing. FIG. 5 is a cross-sectional view showing a modified packing (1). FIG. 6 is a cross-sectional view showing a modified packing (2). FIG. 7 is a cross-sectional view showing a modified packing (3). FIG. 8 is a cross-sectional view of a conventional packing.

[0011] <Outline of Embodiments of the Invention of the Present Disclosure> Below, outlines of embodiments of the invention of the present disclosure will be listed and described.

[0012] (1) A rolling bearing device of the present disclosure comprises: a pestle-type roll; an axle box; an inner ring that rotates integrally with the pestle-type roll and has an inner ring raceway; an outer ring that has an outer ring raceway facing the inner ring raceway and is attached to the axle box; a plurality of rollers that are arranged between the inner ring raceway and the outer ring raceway; a labyrinth ring that is attached to the axle box so as to radially face an end of the inner ring in the axial direction; a packing that is attached to the inner ring and makes sliding contact with the labyrinth ring; and an oil seal that is attached to the inner ring and makes sliding contact with the labyrinth ring, wherein the pestle-type roll has a small diameter shaft portion to which the inner ring is attached and two large diameter portions having a diameter larger than that of the small diameter shaft portion, and a first seal groove to which the packing is attached and a second seal groove to which the oil seal is attached are provided on the outer periphery of the inner ring. The first seal groove has a first annular side surface, a second annular side surface axially opposite the first side surface, and a groove bottom surface provided between the first side surface and the second side surface, and the packing has: a cylindrical portion in sliding contact with the labyrinth ring; an elastically deformable biasing portion provided radially inside the cylindrical portion; a first protrusion in continuous circumferential contact with the first side surface; and a second protrusion in continuous circumferential contact with the second side surface, and the biasing portion has a plurality of contact portions that are provided intermittently along the circumferential direction and contact the groove bottom surface.

[0013] According to the rolling bearing device, the packing is interposed between the groove bottom surface and the labyrinth ring with the biasing portion elastically compressed and deformed in the radial direction. The radially elastically compressed deformation of the biasing portion allows the cylindrical portion to conform to and contact the labyrinth ring. The contact portions of the biasing portion are provided intermittently along the circumferential direction. Therefore, for example, if the biasing portion is significantly compressed in the radial direction relative to the first seal groove, a portion of the biasing portion can elastically deform to escape in the circumferential direction, and the burden on the biasing portion is less than that of biasing portions of conventional technology.

[0014] As a result, the packing can follow and contact the labyrinth ring, preventing the interference between the packing and the labyrinth ring from becoming smaller. The contact portions are provided intermittently along the circumferential direction, and the biasing portion has a range where it does not contact the groove bottom surface. Therefore, the first protrusion continuously contacts the first side surface in the circumferential direction, and the second protrusion continuously contacts the second side surface in the circumferential direction. Therefore, sealing performance is maintained between the first seal groove and the packing.

[0015] (2) Preferably, the biasing portion has a non-contact portion that connects two of the contact portions that are adjacent in the circumferential direction and does not contact the bottom surface of the groove. In this case, even if the biasing portion and the tubular portion are made of different materials, the biasing portion and the tubular portion are strongly bonded to each other. In other words, the biasing portion, which has multiple contact portions that are provided intermittently, is unlikely to come off the tubular portion.

[0016] (3) Preferably, the contact portion has a radially outer portion fixed to the cylindrical portion and a radially inner portion integral with the radially outer portion, the radially inner portion having two support portions extending separately on both circumferential sides from the radially outer portion and contacting the groove bottom surface, and a gap is formed between the two support portions and the groove bottom surface. In this case, when a radial load is applied to the packing, the two support portions elastically deform. This makes the packing more susceptible to elastic deformation and easier to follow the labyrinth ring.

[0017] (4) In the rolling bearing device of (1) or (2), preferably, the contact portion has a radially outer portion fixed to the cylindrical portion and a radially inner portion integral with the radially outer portion, and the radially inner portion has a circumferential dimension that varies along the radial direction. In this case, the portion of the contact portion with a small circumferential dimension is more likely to elastically deform, and the packing is more likely to follow the labyrinth ring.

[0018] (5) Preferably, in the rolling bearing device of any one of (1) to (4), the inner ring is a split raceway ring, the outer ring has a convex portion along a spherical surface on its outer periphery, and the axle box has a first axle box member having a concave portion along the spherical surface on which the convex portion can slide, and a second axle box member that combines with the first axle box member. In this configuration, a bearing unit having the inner ring, a plurality of rollers, the outer ring, and the axle box is located on the outer periphery of the small diameter shaft portion of the mallet-type roll, and the mallet-type roll is supported by the axle box via the bearing unit.

[0019] <Details of the embodiment of the invention of the present disclosure> Hereinafter, an embodiment of the invention of the present disclosure will be described. [Overall configuration of rolling bearing device] Fig. 1 is a cross-sectional view showing an example of a rolling bearing device 10. The rolling bearing device 10 is a device including a mallet-type roll 3 and a bearing unit 19. The bearing unit 19 has an inner ring 11, an outer ring 15, a plurality of cylindrical rollers (rolling elements) 13, a labyrinth ring 31, a packing 32, an oil seal 33, and a chock 14. The bearing unit 19 supports the mallet-type roll 3.

[0020] The pestle-shaped roll 3 is used in a continuous casting machine. The pestle-shaped roll 3 sandwiches and moves a cast piece together with another opposing pestle-shaped roll. The pestle-shaped roll 3 casts the moving cast piece while compressing it. The pestle-shaped roll 3 integrally comprises a central small-diameter shaft portion 4 and two large-diameter portions 5, 5 provided on both axial sides of the small-diameter shaft portion 4. The large-diameter portion 5 has a larger diameter than the small-diameter shaft portion 4. The small-diameter shaft portion 4 of the pestle-shaped roll 3 is supported by a bearing unit 19.

[0021] In the rolling bearing device 10 of the present disclosure, in which the central axis of the pestle-type roll 3 and the central axis L1 of the bearing unit 19 coincide with each other, the direction parallel to the central axis L1 is the axial direction of the rolling bearing device 10. In this disclosure, the direction parallel to the central axis L1 is simply referred to as the "axial direction." The direction perpendicular to the central axis L1 is the radial direction of the rolling bearing device 10. In this disclosure, the direction perpendicular to the central axis L1 is simply referred to as the "radial direction." The direction along a circle centered on the central axis L1 is the circumferential direction of the rolling bearing device 10. In this disclosure, the direction along a circle centered on the central axis L1 is simply referred to as the "circumferential direction." The common bed plate side of the casting machine segments to which the chocks 17 are fixed is referred to as the "bottom," and the opposite side is referred to as the "top." FIG. 1 is a cross-sectional view taken along a plane including the central axis L1 and a vertical direction. In the cross section shown in FIG. 1, the rolling bearing device 10 has a symmetrical configuration between a first axial side and a second axial side of the axial center of the small diameter shaft portion.

[0022] The labyrinth ring 31, the packing 32, and the oil seal 33 are arranged on both axial sides of the rolling bearing device 10. The labyrinth ring 31, the packing 32, and the oil seal 33 on the first axial side have the same configuration as those on the second axial side, and are arranged symmetrically.

[0023] The axle box 14 has a two-piece structure, divided into upper and lower halves. The axle box 14 has a first axle box member 17 fixed to the common bed plate of the caster segments, and a second axle box member 18 placed on top of the first axle box member 17. The first axle box member 17 and the second axle box member 18 are connected and fixed by bolts or the like (not shown). The first axle box member 17 has a concave, spherical inner surface 17a on its upper surface. The first axle box member 17 is an aligning ring.

[0024] The outer ring 15 has a configuration in which an aligning outer ring is divided in half by a plane including its central axis. The inner peripheral surface of the outer ring 15 has a shape that follows a cylindrical surface centered on the central axis L1. The inner peripheral surface of the outer ring 15 has an outer ring raceway 15c. The outer ring 15 has a convex spherical outer diameter surface 15d that is able to abut and slide against the concave, spherical inner surface 17a.

[0025] The second axle box member 18 is the upper member of the axle box 14. The inner circumferential surface of the second axle box member 18 has a shape that follows a cylindrical surface centered on the central axis L1. The inner circumferential surface of the second axle box member 18 has an outer ring raceway 18c. By aligning the central axes of the outer ring 15 and the second axle box member 18 and combining them, a single outer ring raceway is formed by the outer ring raceway 15c and the outer ring raceway 18c. The radius of the outer ring raceway 18c is slightly larger than the radius of the outer ring raceway 15c. The outer ring 15 can swing relative to the first axle box member 17 in accordance with the inclination of the inner ring 11. In contrast, the second axle box member 18 does not swing relative to the first axle box member 17.

[0026] The inner ring 11 is fitted onto the small diameter shaft portion 4 and attached thereto. The inner ring 11 rotates integrally with the punch-type roll 3. The inner ring 11 is a split raceway ring. The inner ring 11 has a first inner ring segment 11a and a second inner ring segment 11b, each having a semi-cylindrical shape. The split surfaces of these inner ring segments 11a, 11b are on a plane including the central axis of the inner ring 11. The inner ring segments 11a, 11b are connected and fixed with bolts or the like (not shown) to form an integrated cylindrical member (inner ring 11). The inner ring 11 has a cylindrical inner ring raceway 11c on its outer periphery. The inner ring 11 has flanges 20, 20 on both axial sides of the inner ring raceway 11c, each having a larger diameter than the inner ring raceway 11c.

[0027] The inner ring raceway 11c and the outer ring raceways 15c, 18c are opposed to each other in the radial direction. The rollers 13 are disposed between the inner ring raceway 11c and the outer ring raceways 15c, 18c. When the pestle-shaped roll 3 rotates together with the inner ring 11 relative to the outer ring 15 and the axle box 14, the rollers 13 roll on the inner ring raceway 11c and the outer ring raceways 15c, 18c.

[0028] Figure 2 is a cross-sectional view showing a portion of the first axial side of the rolling bearing device 10 shown in Figure 1. The diameter of the outer peripheral surface 20a of the collar 20 of the inner ring 11 is larger than the diameter of the inner ring raceway 11c. A first seal groove 71 and a second seal groove 72 are provided in the outer peripheral surface 20a of the collar 20. The first seal groove 71 and the second seal groove 72 are each annular grooves. The seal grooves 71, 72 are recessed radially inward from the outer peripheral surface 20a. The first seal groove 71 is a groove for mounting the packing 32, and the second seal groove 72 is a groove for mounting the oil seal 33.

[0029] FIG. 3 is a cross-sectional view illustrating the packing 32 and the first seal groove 71. The first seal groove 71 has an annular first side surface 66, an annular second side surface 67 axially opposed to the first side surface 66, and a groove bottom surface 68 provided between the first side surface 66 and the second side surface 67. The first side surface 66 is an annular flat surface extending radially inward from a portion of the outer peripheral surface 20a of the inner ring 11. The second side surface 67 is an annular flat surface extending radially inward from another portion of the outer peripheral surface 20a of the inner ring 11. The groove bottom surface 68 is a cylindrical surface extending axially from the radially inner end of the first side surface 66 and connecting to the radially inner end of the second side surface 67. The groove bottom surface 68 is a cylindrical surface centered on the central axis of the inner ring 11. Although not shown, the groove bottom surface 68 may be a surface other than the cylindrical surface described above, such as a conical surface or a portion of a torus.

[0030] [Labyrinth Ring 31] The labyrinth ring 31 (see FIG. 1) is a cylindrical member as a whole. The labyrinth ring 31 is divided into two parts in the circumferential direction. The labyrinth ring 31 has a first semi-cylindrical portion 31a and a second semi-cylindrical portion 31b. The dividing plane between these semi-cylindrical portions 31a, 31b is on a plane including the central axis of the labyrinth ring 31. The central axis of the labyrinth ring 31 coincides with the central axis of the outer ring 15. The first semi-cylindrical portion 31a, which constitutes the lower half of the labyrinth ring 31, is attached to the first axle box member 17. The second semi-cylindrical portion 31b, which constitutes the upper half of the labyrinth ring 31, is attached to the second axle box member 18. The labyrinth ring 31 faces the axial end (rib 20) of the inner ring 11 in the radial direction.

[0031] The labyrinth ring 31 on the first axial side (the right side in FIG. 1 ) is provided so as to protrude from the axle chock 14 toward the first axial side. A portion 31 c of the labyrinth ring 31 fits into the circumferential groove 6 formed in the large diameter portion 5 of the pestle-shaped roll 3. The labyrinth ring 31 on the second axial side (the left side in FIG. 1 ) is provided so as to protrude from the axle chock 14 toward the second axial side. A portion 31 c of the labyrinth ring 31 fits into the circumferential groove 6 formed in the large diameter portion 5 of the pestle-shaped roll 3. On both sides in the axial direction, labyrinth gaps are formed between the portions 31 c of the labyrinth ring 31 and the circumferential groove 6. The labyrinth gaps prevent foreign matter such as cooling water from entering the inside 16 of the bearing from the outside.

[0032] [Oil seal 33] In Figure 2, the oil seal 33 has a fixed portion 52, lips 53, 54, and a metal ring 55. The fixed portion 52 and the lips 53, 54 are made of rubber. The fixed portion 52 and the lips 53, 54 are integral. The fixed portion 52 and the lips 53, 54 are annular. The fixed portion 52 and the lips 53, 54 are separated at one point in the circumferential direction. The metal ring 55 has two arc-shaped metal plates. The metal ring 55 is fixed to a portion of the fixed portion 52 on a first circumferential side from the separation point and a portion on a second circumferential side from the separation point.

[0033] The oil seal 33 is fitted into the second seal groove 72 and attached. The oil seal 33 is ring-shaped as a whole when attached to the inner ring 11. Because the oil seal 33 is separated at one point in the circumferential direction, it can be attached to the inner ring 11, which has a smaller diameter than the large diameter portion 5 of the mallet-shaped roll 3. When the mallet-shaped roll 3 and the inner ring 11 rotate, the oil seal 33 rotates integrally with the inner ring 11. The lip portions 53, 54 of the oil seal 33 come into sliding contact with the inner peripheral surface 31d of the labyrinth ring 31.

[0034] [Packing 32] In Figure 3, the packing 32 has a cylindrical portion 40, a biasing portion 41, a first protruding portion 46, and a second protruding portion 47. The cylindrical portion 40 is annular. The cylindrical portion 40 is separated at one point in the circumferential direction. When the packing 32 is installed in the first seal groove 71, the separated ends of the cylindrical portion 40 press against each other in the circumferential direction. The cylindrical portion 40 is made of resin. The cylindrical portion 40 may be made of rubber instead of resin. In order to reduce the contact resistance between the cylindrical portion 40 and the labyrinth ring 31, it is preferable that the cylindrical portion 40 be made of resin. In this embodiment, the cylindrical portion 40 is made of polytetrafluoroethylene.

[0035] FIG. 4 is a cross-sectional view of the packing 32, taken along arrow IV in FIG. 3 . In FIG. 4 , the groove bottom surface 68 of the first seal groove 71 is indicated by a two-dot chain line. The biasing portion 41 has multiple contact portions 42 and multiple non-contact portions 43. The contact portions 42 and non-contact portions 43 are alternately arranged in the circumferential direction. The contact portions 42 contact the groove bottom surface 68. The non-contact portions 43 connect two circumferentially adjacent contact portions 42, 42. The non-contact portions 43 do not contact the groove bottom surface 68. The circumferentially adjacent contact portions 42, 42 are connected by the non-contact portions 43. Therefore, the biasing portion 41 of this embodiment is annular as a whole. The biasing portion 41 also separates in the circumferential direction at the one circumferential separation point where the tubular portion 40 separates. The biasing portion 41 is made of rubber and is elastically deformable.

[0036] 3, the urging portion 41, the first protrusion 46, and the second protrusion 47 are integrally formed. The urging portion 41, the first protrusion 46, and the second protrusion 47 are annular. The urging portion 41, the first protrusion 46, and the second protrusion 47 are separated at the same location as the separation location of the tubular portion 40. When the packing 32 is installed in the first seal groove 71, the separated ends of the urging portion 41, the first protrusion 46, and the second protrusion 47 press against each other in the circumferential direction.

[0037] The urging portion 41, the first protrusion 46, and the second protrusion 47 are made of rubber. In this embodiment, the urging portion 41, the first protrusion 46, and the second protrusion 47 are made of fluororubber. The urging portion 41 is fixed to the radially inner side of the tubular portion 40. The urging portion 41 is adhered to the tubular portion 40, for example, with an adhesive. The outer peripheral surface 40a of the tubular portion 40 is a cylindrical surface. A recess 40b is provided on the inner peripheral side of the tubular portion 40. A portion of the urging portion 41 extends into the recess 40b. With this configuration, the tubular portion 40 and the urging portion 41 are firmly joined together.

[0038] The first protrusion 46 is located on a side surface 41 a on a first axial side of the urging portion 41. The second protrusion 47 is located on a side surface 41 b on a second axial side of the urging portion 41. The first protrusion 46 is located closer to the first axial side than the tubular portion 40 and the urging portion 41. The second protrusion 47 is located closer to the second axial side than the tubular portion 40 and the urging portion 41.

[0039] The first protrusion 46 is provided in an annular shape on the side surface 41a of the urging portion 41. The first protrusion 46 is in continuous contact with the first side surface 66 in the circumferential direction. The first protrusion 46 is located on a first axial side from the side surface 41a of the urging portion 41. The second protrusion 47 is provided in an annular shape on the side surface 41b of the urging portion 41. The second protrusion 47 is in continuous circumferential contact with the second side surface 67. The second protrusion 47 is located on a second axial side from the side surface 41b of the urging portion 41. The first protrusion 46 and the second protrusion 47 are molded integrally with the urging portion 41.

[0040] The axial dimension of the cylindrical portion 40 is the same as the axial dimension of the biasing portion 41. The axial dimension of a radially outer portion 41j of the biasing portion 41, which includes a joint with the cylindrical portion 40, is the same as the axial dimension of a radially inner portion 41s of the biasing portion 41 that contacts the groove bottom surface 68. Note that the axial dimension of the radially outer portion 41j is the dimension of a portion excluding the first protrusion 46 and the second protrusion 47.

[0041] The packing 32 is fitted into the first seal groove 71 and attached. The packing 32 is annular as a whole when attached to the inner ring 11. Because the packing 32 is separated at one point in the circumferential direction, it can be attached to the inner ring 11 having a diameter smaller than that of the large diameter portion 5 of the pestle-shaped roll 3. The biasing portion 41 is compressed in the radial direction and elastically deformed at the contact portion 42 between the cylindrical portion 40 and the groove bottom surface 68. The cylindrical portion 40 is pressed against the labyrinth ring 31 by the contact portion 42.

[0042] When the mallet-shaped roll 3 and the inner ring 11 rotate, the packing 32 rotates integrally with the inner ring 11. The cylindrical portion 40 is in sliding contact with the inner peripheral surface 31d of the labyrinth ring 31. The packing 32 and oil seal 33 are in contact with the labyrinth ring 31. The sealing performance of the packing 32, oil seal 33, and labyrinth ring 31 prevents cooling water and casting scale from entering the bearing interior 16, where the plurality of rollers 10 are present, from the outside of the rolling bearing device 10. The oil seal 33 also functions to prevent lubricant, such as grease and oil in oil-air, from leaking to the outside in the bearing interior 16.

[0043] 4, each contact portion 42 has a radially outer portion 41j on the radially outer side and a radially inner portion 41s on the radially inner side. The radially outer portion 41j is connected to the non-contact portion 43. The radially outer portion 41j is integral with the non-contact portion 43 to form an annular shape.

[0044] There are multiple radially inner portions 41s in the circumferential direction. The radially inner portions 41s are provided discontinuously (intermittently) in the circumferential direction. Adjacent radially inner portions 41s in the circumferential direction are spaced apart in the circumferential direction. The radially inner portions 41s are integral with the radially outer portion 41j. The radially inner portions 41s contact the groove bottom surface 68.

[0045] In the embodiment shown in FIG. 4 , the radially inner portion 41s has a first support portion 44 and a second support portion 45. The first support portion 44 is provided to extend from the radially outer portion 41j to a first circumferential side and radially inward. The second support portion 45 is provided to extend from the radially outer portion 41j to a second circumferential side and radially inward. The tip portion 44a of the first support portion 44 and the tip portion 45a of the second support portion 45 contact the groove bottom surface 68. The tip portion 44a of the first support portion 44 and the tip portion 45a of the second support portion 45 are spaced apart in the circumferential direction.

[0046] The state in which the packing 32 is installed in the first seal groove 71 and the cylindrical portion 40 is in contact with the labyrinth ring 31 is referred to as the "installed state of the packing 32." In the installed state of the packing 32, the first support portion 44 is compressed in the radial direction, and the tip portion 44a moves to the first side in the circumferential direction. In the installed state of the packing 32, the second support portion 45 is compressed in the radial direction, and the tip portion 45a moves to the second side in the circumferential direction. The first support portion 44 and the second support portion 45 are pulled apart in the circumferential direction. In the installed state of the packing 32, a gap E exists between the first support portion 44 and the second support portion 45 and the groove bottom surface 68.

[0047] A space P is present radially inward of the non-contact portion 43. When the tubular portion 40 is further pressed radially inward, the contact portion 42 is compressed radially and elastically deformed. When the tip portion 44a slides along the groove bottom surface 68, the contact portion between the tip portion 44a and the groove bottom surface 68 moves toward a first side in the circumferential direction (toward the space P). When the tip portion 44a does not slide along the groove bottom surface 68, the contact portion (contact area) between the tip portion 44a and the groove bottom surface 68 expands toward a second side in the circumferential direction (toward the gap E). When the tip portion 45a slides along the groove bottom surface 68, the contact portion between the tip portion 45a and the groove bottom surface 68 moves toward the second side in the circumferential direction (toward the space P). When the tip portion 45a does not slide along the groove bottom surface 68, the contact portion (contact area) between the tip portion 45a and the groove bottom surface 68 expands toward the first side in the circumferential direction (toward the gap E).

[0048] Furthermore, the radially inner portion 41s can expand toward the space P or the gap E. When the tubular portion 40 is further pressed radially inward, the contact portion 42 is compressed radially, and the radially inner portion 41s can escape into the space P or the gap E. Therefore, the tubular portion 40 can easily move radially.

[0049] When the packing 32 is installed (see FIG. 3 ), the first protrusion 46 comes into contact with the first side surface 66 with an interference. The second protrusion 47 comes into contact with the second side surface 67 with an interference. When the tubular portion 40 moves in the radial direction, the first protrusion 46 can move in the radial direction while remaining in contact with the first side surface 66. When the tubular portion 40 moves in the radial direction, the second protrusion 47 can move in the radial direction while remaining in contact with the second side surface 67.

[0050] [Modification (1) of Packing 32] Figure 5 is a cross-sectional view showing Modification (1) of the packing 32. The modifications described below differ from the embodiment shown in Figure 4 in the configuration of the urging portion 41. The modifications are the same in that the urging portion 41 includes a contact portion 42 and a non-contact portion 43, that multiple contact portions 42 are provided intermittently along the circumferential direction and each contact portion 42 contacts the groove bottom surface 68, that the non-contact portion 43 connects two circumferentially adjacent contact portions 42 and does not contact the groove bottom surface 68, and that the contact portion 42 has a radially outer portion 41j and a radially inner portion 41s. In the embodiment shown in Figure 4, the radially inner portion 41s contacts the groove bottom surface 68 at two locations: a first support portion 44 and a second support portion 45.

[0051] In the case of the modified example (1) shown in FIG. 5 , the radially inner portion 41s contacts the groove bottom surface 68 at one location. The radially inner portion 41s has a shape in which the circumferential dimension decreases from the radially outer portion 41j toward the groove bottom surface 68. The configuration of the contact portion 42 in the modified example (1) facilitates molding (demolding) of the biasing portion 41. When the tubular portion 40 is further pressed radially inward, the contact portion 42 is compressed radially and elastically deformed. At this time, the radially inner portion 41s can expand toward the space P.

[0052] [Modification (2) of Packing 32] FIG. 6 is a cross-sectional view showing Modification (2) of the packing 32. In Modification (2) shown in FIG. 6, the radially inner portion 41s contacts the groove bottom surface 68 at one location. Modification (2) shown in FIG. 6 differs from Modification (1) shown in FIG. 5 in the shape of the radially inner portion 41s. The radially inner portion 41s has a shape in which the circumferential dimension increases toward the groove bottom surface 68. In Modification (2), the contact area of ​​the contact portion 42 with the groove bottom surface 68 increases, making it difficult for the packing 32 to be displaced circumferentially relative to the inner ring 11. When the tubular portion 40 is further pressed radially inward, the contact portion 42 is compressed radially and elastically deformed. At this time, the radially inner portion 41s can expand toward the space P.

[0053] As described above, in the modified example (1) shown in Fig. 5 and the modified example (2) shown in Fig. 6, the circumferential dimension of the contact portion 42 varies along the radial direction of the contact portion 42. The contact portion 42 has, at least in part, a radially inner portion 41s whose circumferential dimension varies along the radial direction.

[0054] [Modification (3) of Packing 32] FIG. 7 is a cross-sectional view showing Modification (3) of the packing 32. In Modification (3) shown in FIG. 7, the radially inner portion 41s contacts the groove bottom surface 68 at one location. Modification (3) differs from Modifications (1) and (2) in the shape of the radially inner portion 41s. A first circumferential side surface 49a of the radially inner portion 41s and a second circumferential side surface 49b of the radially inner portion 41s are parallel to each other. The first side surface 49a and the second side surface 49b are parallel to each other in the axial direction. An imaginary plane is located along the radial direction at a center position between the first side surface 49a and the second side surface 49b.

[0055] The circumferential (tangential) dimension between the first side surface 49a and the second side surface 49b does not change. In other words, the tangential dimension of the radially inner portion 41s is constant along the radial extension direction of the radially inner portion 41s. When the cylindrical portion 40 is further pressed radially inward, the contact portion 42 is compressed radially and elastically deformed. At this time, the radially inner portion 41s can expand toward the space P.

[0056] The cross-sectional shape of the contact portion 42 of the packing 32 in each of the embodiments shown in Figure 5, Figure 6, and Figure 7 is the same as the shape shown in Figure 3. The packing 32 in each of the embodiments shown in Figure 5, Figure 6, and Figure 7 also has annular first protrusions 46 and second protrusions 47.

[0057] [Regarding the Rolling Bearing Device 10 of Each Embodiment] As described above, the rolling bearing device 10 of each embodiment includes the packing 32 attached to the inner ring 11 and in sliding contact with the labyrinth ring 31. The packing 32 of each embodiment includes a cylindrical portion 40 that is in sliding contact with the labyrinth ring 31, an elastically deformable biasing portion 41 that is provided radially inside the cylindrical portion 40, a first protrusion 46 that is in continuous contact with the first side surface 66 of the first seal groove 71 in the circumferential direction, and a second protrusion 47 that is in continuous contact with the second side surface 67 of the first seal groove 71 in the circumferential direction. The biasing portion 41 has a plurality of contact portions 42. The plurality of contact portions 42 are provided intermittently along the circumferential direction and contact the groove bottom surface 68 of the first seal groove 71.

[0058] In the rolling bearing device 10 equipped with the packing 32 of any of the above embodiments, the packing 32 is interposed between the groove bottom surface 68 and the labyrinth ring 31 with the biasing portion 41 elastically compressed and deformed in the radial direction. The biasing portion 41 elastically compresses and deforms in the radial direction, and a state is achieved in which the cylindrical portion 40 follows and contacts the labyrinth ring 31. Moreover, the contact portions 42 of the biasing portion 41 are provided intermittently along the circumferential direction. Therefore, in the first seal groove 71, for example, even if the biasing portion 41 is significantly compressed in the radial direction, part of the biasing portion 41 can elastically deform so as to escape in the circumferential direction, and the burden on the biasing portion 41 is less than that of packings of conventional structures.

[0059] As described above, the packing 32 can follow and contact the labyrinth ring 31, and a decrease in the interference between them is suppressed. The contact portions 42 are provided discontinuously (intermittently) along the circumferential direction, and there are ranges in the biasing portion 41 that do not contact the first seal groove 71. However, the first protrusion 46 continuously contacts the first side surface 66 of the first seal groove 71 in the circumferential direction. The second protrusion 47 continuously contacts the second side surface 67 of the first seal groove 71 in the circumferential direction. Therefore, the sealing performance between the first seal groove 71 and the packing 32 is ensured.

[0060] In each of the above-described forms of the packing 32, the urging portion 41 further includes a non-contact portion 43 that connects two circumferentially adjacent contact portions 42, 42 and is not in contact with the groove bottom surface 68. Therefore, the joint area between the urging portion 41 and the tubular portion 40 expands along the circumferential direction, and the urging portion 41 and the tubular portion 40 are strongly joined together even if they are made of different materials. In other words, the urging portion 41, which has multiple contact portions 42 that are provided intermittently, is less likely to come off the tubular portion 40.

[0061] In the case of the packing 32 shown in FIG. 4 , the contact portion 42 has a radially outer portion 41j fixed to the cylindrical portion 40 and a radially inner portion 41s that is integral with the radially outer portion 41j. The radially inner portion 41s has two support portions 44, 45. The support portions 44, 45 extend separately to both sides in the circumferential direction from the radially outer portion 41j and contact the groove bottom surface 78. In the case of this packing 32 in which a gap E is formed between the two support portions 44, 45 and the groove bottom surface 78, when a radial load is applied, the contact portion 42 elastically deforms in the radial direction, and the two support portions 44, 45 also deform. The packing 32 has a large amount of elastic deformation and is therefore more likely to follow the labyrinth ring 31.

[0062] In the case of the packing 32 shown in FIGS. 5 and 6 , the contact portion 42 has a radially outer portion 41j fixed to the cylindrical portion 40 and a radially inner portion 41s that is integral with the radially outer portion 41j. The circumferential dimension of the radially inner portion 41s varies along the radial direction. In the case of such a packing 32, the contact portion 42 is more likely to elastically deform in the portion with a small circumferential dimension. Therefore, the packing 32 shown in FIGS. 5 and 6 is more likely to conform than the packing 32 shown in FIG. 7 . In the configurations shown in FIGS. 5 , 6 , and 7 , the conformity of the packing 32 is achieved by the radial elastic deformation of the entire contact portion 42.

[0063] [Others] The shape of the contact portion 42 can be modified within the scope of the present disclosure. For example, in the configurations shown in Figures 5 and 6, the circumferential dimension of the radially inner portion 41s varies linearly along the radial direction of the contact portion 42. In other words, the circumferential side surface of the radially inner portion 41s is flat. In other configurations, the circumferential dimension of the radially inner portion 41s may vary non-linearly along the radial direction of the contact portion 42. Furthermore, the packing of the rolling bearing device of the present invention may be a packing 32 that combines at least two of the contact portions 42 of the configurations shown in Figures 4, 5, 6, and 7.

[0064] The above-described embodiments are illustrative in all respects and are not limiting. The scope of the present invention is defined by the claims rather than the above-described embodiments, and includes all modifications within the scope equivalent to the configurations described in the claims.

[0065] 3 Pestle-shaped roll 4 Small diameter shaft portion 5 Large diameter portion 10 Rolling bearing device 11 Inner ring 11c Inner ring raceway 13 Roller 14 Journal box 15 Outer ring 15c Outer ring raceway 15d Spherical outer diameter surface (convex portion) 17 First journal box member 17a Concave inner surface (concave portion) 18 Second journal box member 31 Labyrinth ring 32 Packing 33 Oil seal 40 Cylindrical portion 41 Urging portion 41j Radially outer portion 41s Radially inner portion 42 Contact portion 43 Non-contact portion 44 First support portion 45 Second support portion 46 First protruding portion 47 Second protruding portion 66 First side surface 67 Second side surface 68 Groove bottom surface 71 First seal groove 72 Second seal groove E gap

Claims

1. A pestle-shaped roll; Axle box and An inner ring that rotates integrally with the pestle roll and has an inner ring raceway; an outer ring having an outer ring raceway facing the inner ring raceway and attached to the axle box; a plurality of rollers disposed between the inner ring raceway and the outer ring raceway; a labyrinth ring attached to the axle box so as to be radially opposed to an axial end of the inner ring; a packing attached to the inner ring and in sliding contact with the labyrinth ring; an oil seal attached to the inner ring and in sliding contact with the labyrinth ring; Equipped with The pestle-shaped roll has a small diameter shaft portion to which the inner ring is attached, and two large diameter portions having a diameter larger than that of the small diameter shaft portion, A first seal groove in which the packing is attached and a second seal groove in which the oil seal is attached are provided on an outer periphery of the inner ring. the first seal groove has an annular first side surface, an annular second side surface axially opposed to the first side surface, and a groove bottom surface provided between the first side surface and the second side surface, The packing is a cylindrical portion that is in sliding contact with the labyrinth ring; a biasing portion provided on a radially inner side of the cylindrical portion and capable of elastic deformation; a first protrusion that is in continuous contact with the first side surface in a circumferential direction; a second protruding portion that is in continuous contact with the second side surface in a circumferential direction; having The biasing portion has a plurality of contact portions that are provided intermittently along a circumferential direction and contact the groove bottom surface. Rolling bearing device.

2. The rolling bearing device according to claim 1 , wherein the biasing portion has a non-contact portion that connects two of the contact portions adjacent to each other in the circumferential direction and is not in contact with the groove bottom surface.

3. The contact portion is A radially outer portion fixed to the cylindrical portion; a radially inner portion integral with the radially outer portion, The radially inner portion has two support portions extending separately from the radially outer portion to both sides in the circumferential direction and contacting the groove bottom surface, and a gap is formed between the two support portions and the groove bottom surface.

3. The rolling bearing device according to claim 1 or 2.

4. The contact portion is A radially outer portion fixed to the cylindrical portion; a radially inner portion integral with the radially outer portion, 3. The rolling bearing device according to claim 1, wherein the radially inner portion has a circumferential dimension that varies along the radial direction.

5. The inner ring is a split raceway ring, the outer ring has a convex portion along a spherical surface on its outer circumferential side, The axle box includes a first axle box member having a recess along a spherical surface on which the protrusion is slidable, and a second axle box member that is combined with the first axle box member.

3. The rolling bearing device according to claim 1 or 2.