Rolling bearing device

Abstract

A rolling bearing device comprises an inner ring 11 that rotates integrally with a mallet-type roll 3, an outer ring device 12, a plurality of rollers 13, a labyrinth ring 31 attached to an axle box 17, and an oil seal 33 that is in sliding contact with the labyrinth ring 31. A second seal groove 72, to which the oil seal 33 is attached, is provided on the outer periphery of the inner ring 11. The second seal groove 72 has a first side surface 76, a second side surface 77, and a groove bottom surface 78. The oil seal 33 includes a fixing part 51 provided along the groove bottom surface 78, a lip part 55 that is in contact with the labyrinth ring 31, and an urging part 52. The urging part 52 has a first extending part 61 extending from the fixing part 51, and a second extending part 62 extending from a relay part 64 of the first extending part 61. At least some of the first extending part 61 and the second extending part 62 is provided between the first side surface 76 and the second side surface 77, and the relay part 64 is able to come into contact with the side surface 76.

Description

[Technical Field]

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

[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 each 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 located, 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 oil seal are attached to the inner ring. The packing and oil seal come into contact with the labyrinth ring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-190835 Summary of the Invention [Problem to be solved by the invention]

[0005] As shown in Fig. 5, the rolling bearing device disclosed in Patent Document 1 has a seal groove in an inner ring 91. An oil seal 99 is fitted in the seal groove 92. The oil seal 99 has a lip portion 98. The lip portion 98 contacts an inner peripheral surface 96a of a labyrinth ring 96. Because the lip portion 98 is located on the outer peripheral side of the oil seal 99, it is difficult to attach a ring-shaped spring to the lip portion 98 and increase the tension force of the lip portion 98 against the labyrinth ring 96.

[0006] Therefore, in order to increase the tensioning force of the lip portion 98, it is conceivable to set a large interference between the lip portion 98 and the labyrinth ring 96. However, in this case, the following problem arises. For example, if the gap between the groove bottom surface 92c of the seal groove 92 and the inner circumferential surface 96a of the labyrinth ring 96 is narrow in part of the circumferential direction due to the assembly precision of the rolling bearing device, the lip portion 98 will be unevenly crushed in part of the circumferential direction. In this case, the rotational resistance of the rolling bearing device will increase, and the contact state of the lip portion 98 with the labyrinth ring 96 will differ from what was expected, resulting in a deterioration in sealing performance.

[0007] Therefore, an object of the present disclosure is to provide a rolling bearing device equipped with an oil seal in which the lip portion is less likely to be crushed and can come into contact with the labyrinth ring with a desired interference. [Means for solving the problem]

[0008] The rolling bearing device of the present disclosure is A pestle-shaped roll; Axle boxes and an inner ring that rotates integrally with the pestle-shaped roll and has an inner ring raceway; an outer ring having an outer ring raceway opposite 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 face radially 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 second 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 oil seal is a fixing portion provided along the bottom surface of the groove; a lip portion that contacts the labyrinth ring; a biasing portion provided between the fixing portion and the lip portion, The biasing portion is a first extension portion extending radially outward from the fixing portion and to a first side in the axial direction; a second extension portion extending radially outward from a relay portion that is a radially outer portion of the first extension portion and toward a second side in the axial direction, The entire first extension portion and at least a part of the second extension portion are provided between the first side surface and the second side surface, and the relay portion can contact the side of the first side surface and the second side surface that is adjacent to the relay portion. [Effects of the Invention]

[0009] According to the rolling bearing device of the present disclosure, the lip portion of the oil seal is less likely to be crushed, and can come into contact with the labyrinth ring with a desired interference. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a cross-sectional view showing an example of a rolling bearing device. [Figure 2] 2 is a cross-sectional view showing a part of the first axial side of the rolling bearing device shown in FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view illustrating the oil seal and the second seal groove. [Figure 4] FIG. 4 is a cross-sectional view showing a modified example of the oil seal. [Figure 5] FIG. 5 is a cross-sectional view of a conventional oil seal. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Summary of the embodiments of the presently disclosed invention> Below, an outline of the embodiments of the present disclosure will be listed and described.

[0012] (1) The rolling bearing device of the present disclosure is A pestle-shaped roll; Axle boxes and an inner ring that rotates integrally with the pestle-shaped roll and has an inner ring raceway; an outer ring having an outer ring raceway opposite 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 face radially 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 second 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 oil seal is a fixing portion provided along the bottom surface of the groove; a lip portion that contacts the labyrinth ring; a biasing portion provided between the fixing portion and the lip portion, The biasing portion is a first extension portion extending radially outward from the fixing portion and to a first side in the axial direction; a second extension portion extending radially outward from a relay portion that is a radially outer portion of the first extension portion and toward a second side in the axial direction, The entire first extension portion and at least a part of the second extension portion are provided between the first side surface and the second side surface, and the relay portion can contact the side of the first side surface and the second side surface that is adjacent to the relay portion.

[0013] According to the rolling bearing device, the oil seal is interposed between the groove bottom surface and the labyrinth ring in a state of elastic compression deformation in the radial direction. The elastic compression deformation and elastic restoring force of the biasing portion cause the lip portion to follow and contact the labyrinth ring. Because the first and second extension portions of the biasing portion each undergo elastic deformation, the oil seal as a whole is prone to elastic deformation in the radial direction, reducing the rigidity of the oil seal. As a result, even if the gap between the groove bottom surface and the inner peripheral surface of the labyrinth ring is narrowed in part of the circumferential direction, the lip portion is less likely to be crushed unevenly. Therefore, the lip portion can contact the labyrinth ring with the desired interference.

[0014] Even if the biasing portion is displaced in the axial direction in conjunction with elastic deformation in the radial direction, the relay portion can contact the side surface of the second seal groove. The biasing portion is restricted in position by the side surface, and the oil seal is less likely to lose its overall posture. The lip portion can contact the labyrinth ring while maintaining the desired interference.

[0015] (2) Preferably, a gap is provided between the linking portion and a side surface adjacent to the linking portion, so that the linking portion comes into contact with the side surface when the inner ring and the labyrinth ring move relative to each other in the axial direction. If there is no gap between the linking portion and the side surface adjacent to the linking portion and the axial width dimension of the first extending portion is the same as or larger than the axial dimension of the second seal groove, the biasing portion may be constrained by the side surface. However, by providing the gap, the biasing portion is less likely to be constrained by the side surface, the lip portion can easily follow the labyrinth ring, and sealing performance is not reduced.

[0016] (3) Preferably, the biasing portion has a third extending portion that extends radially outward and axially toward the first side from a second relay portion that is a radially outer portion of the second extending portion, and the lip portion extends from the radially outer portion of the third extending portion toward the labyrinth ring. With this configuration, the range over which the oil seal can elastically deform in the radial direction can be increased.

[0017] <Details of the embodiment of the present disclosure> Hereinafter, embodiments of the present disclosure will be described. [Overall configuration of rolling bearing device] 1 is a cross-sectional view showing an example of a rolling bearing device 10. The rolling bearing device 10 is a device equipped with a pestle-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 pestle-type roll 3.

[0018] The pestle-shaped roll 3 is used in a continuous casting machine. The pestle-shaped roll 3 sandwiches and moves the slab together with another opposing pestle-shaped roll. The pestle-shaped roll 3 casts the moving slab 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.

[0019] In the rolling bearing device 10 of the present disclosure, the central axis of the pestle-shaped roll 3 coincides with the central axis L1 of the bearing unit 19, and the direction parallel to the central axis L1 is the axial direction of the rolling bearing device 10. In the present 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 the present 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." axle box 14 The side of the common bedplate of the caster segments to which they are fixed is called the "bottom" side and the opposite side is called the "top" side. 1 is a cross-sectional view taken along a plane including a central axis L1 and a direction perpendicular to the central axis L1. 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 at the axial center of the small diameter shaft portion.

[0020] The labyrinth ring 31, packing 32, and oil seal 33 are arranged on both axial sides of the rolling bearing device 10. The labyrinth ring 31, packing 32, and oil seal 33 on the first axial side and those on the second axial side have the same configuration and are arranged symmetrically.

[0021] 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 side. The first axle box member 17 is an aligning ring.

[0022] 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.

[0023] The second axle box member 18 is the upper member of the axle box 14. The inner peripheral surface of the second axle box member 18 has a shape that follows a cylindrical surface centered on the central axis L1. The inner peripheral 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.

[0024] The inner ring 11 is fitted onto the small diameter shaft portion 4 and attached to it. 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.

[0025] The inner ring raceway 11c and the outer ring raceways 15c, 18c face 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.

[0026] 2 is a cross-sectional view showing a portion of the first axial side of the rolling bearing device 10 shown in FIG. 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.

[0027] As will be explained later, the packing 32 and the oil seal 33 come into contact with the inner peripheral surface 31d of the labyrinth ring 31. The sealing performance of the packing 32, the oil seal 33 and the labyrinth ring 31 prevents cooling water and cast scale from the outside of the rolling bearing device 10 and into the plural rollers. 13 The oil seal 33 also functions to prevent lubricants, such as grease and oil in oil-air, from leaking to the outside.

[0028] FIG. 3 is a cross-sectional view illustrating the oil seal 33 and the second seal groove 72. The second seal groove 72 has an annular first side surface 76, an annular second side surface 77 axially opposed to the first side surface 76, and a groove bottom surface 78 provided between the first side surface 76 and the second side surface 77. The first side surface 76 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 77 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 78 is a cylindrical surface extending axially from the radially inner end of the first side surface 76 and connecting to the radially inner end of the second side surface 77. The groove bottom surface 78 is a cylindrical surface centered on the central axis of the inner ring 11. Although not shown, the groove bottom surface 78 may be a surface other than the cylindrical surface described above, such as a conical surface or a portion of a torus.

[0029] [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 of 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.

[0030] The labyrinth ring 31 on the first axial side (the right side in FIG. 1 ) is provided so as to protrude from the axle box 14 toward the first axial side. A part 31c of the labyrinth ring 31 is inserted 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 (left side in FIG. 1 ) is provided so as to protrude from the axle box 14 toward the second axial side. A part 31c of the labyrinth ring 31 is inserted 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, a labyrinth gap is formed between a portion 31c of the labyrinth ring 31 and the circumferential groove 6. The labyrinth gap prevents foreign matter such as cooling water from entering the interior 16 of the bearing from the outside.

[0031] [Packing 32] As shown in Fig. 2, the packing 32 is fitted into the first seal groove 71 and attached. The packing 32 has a cylindrical portion 40 that is in sliding contact with the labyrinth ring 31, and an urging portion 41 that is provided on the radially inner side of the cylindrical portion 40. The entire packing 32, including the cylindrical portion 40, may be made of rubber, but the cylindrical portion 40 is made of resin to reduce contact resistance with the labyrinth ring 31. The packing 32 is separated at one point in the circumferential direction. The packing 32 has a ring shape as a whole when attached to the inner ring 11. The packing 32 is separated at one point in the circumferential direction, so that 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. When the pestle-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.

[0032] [Oil seal 33] The oil seal 33 is fitted into the second seal groove 72 and attached. The oil seal 33 has a ring shape as a whole when attached to the inner ring 11. The oil seal 33 is separated at one point in the circumferential direction, so that 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. When the pestle-shaped roll 3 and the inner ring 11 rotate, the oil seal 33 rotates integrally with the inner ring 11. Lip portions 53, 54 of the oil seal 33 come into sliding contact with the inner peripheral surface 31d of the labyrinth ring 31.

[0033] As shown in FIG. 3 , the oil seal 33 has a fixed portion 51, a biasing portion 52, a first lip portion 53, and a second lip portion 54. Hereinafter, the first lip portion 53 and the second lip portion 54 are collectively referred to as the "lip portion 55." The fixed portion 51 is provided along the groove bottom surface 78. The lip portion 55 contacts the inner circumferential surface 31d of the labyrinth ring 31. The biasing portion 52 is provided between the fixed portion 51 and the lip portion 55. The fixed portion 51, the biasing portion 52, the first lip portion 53, and the second lip portion 54 are made of rubber and are elastically deformable.

[0034] The fixed portion 51 has a cylindrical shape. The fixed portion 51 has protrusions 56 that protrude radially inward from its inner circumferential surface. The protrusions 56 are provided at multiple locations in the circumferential direction. The groove bottom surface 78 is provided with holes 57 into which the protrusions 56 are inserted. By inserting the protrusions 56 into the holes 57, the oil seal 33 does not rotate relative to the inner ring 11.

[0035] The biasing portion 52 has a first extending portion 61 and a second extending portion 62. In the oil seal 33 shown in FIG.

[0036] The first extending portion 61 is a portion that extends radially outward from the fixed portion 51 and toward a first axial side (the right side in FIG. 3 ). The first extending portion 61 extends from a portion including an end portion 51 a on the second axial side (the left side in FIG. 3 ) of the fixed portion 51. A gap e1 is provided in the radial direction between a first relay portion 64, which is a radially outer portion of the first extending portion 61, and an end portion 51 b on the first axial side (the right side in FIG. 3 ) of the fixed portion 51.

[0037] The second extending portion 62 extends radially outward and toward a second axial side (left side in FIG. 3 ) from the first relay portion 64. A gap e2 is provided radially between the second relay portion 65, which is the radially outer portion of the second extending portion 62, and the end portion 61 a of the first extending portion 61 on the second axial side (left side in FIG. 3 ).

[0038] The third extending portion 63 extends radially outward from the second relay portion 65 of the second extending portion 62 and toward a first axial side (the right side in FIG. 3 ). A gap e3 is provided radially between the third relay portion 66, which is the radially outer portion of the third extending portion 63, and the end portion 62a on the first axial side (the right side in FIG. 3 ) of the second extending portion 62. The lip portion 55 extends from the third relay portion 66 of the third extending portion 63 toward the labyrinth ring 31.

[0039] The first lip portion 53 extends radially outward from the third link portion 66 toward a second axial side (the left side in FIG. 3 ). The second lip portion 54 extends radially outward from the third link portion 66 toward a first axial side (the right side in FIG. 3 ).

[0040] The entire first extending portion 61 and the entire second extending portion 62 are disposed between the first side surface 76 and the second side surface 77. That is, the entire first extending portion 61 and the entire second extending portion 62 are disposed within the range of the second seal groove 72. The first relay portion 64 is capable of contacting the adjacent first side surface 76. In the present embodiment, a gap E1 is provided between the first relay portion 64 and the first side surface 76. When the inner ring 11 and the labyrinth ring 31 move relative to each other in the axial direction, the biasing portion 52 elastically deforms in the axial direction, and the first relay portion 64 comes into contact with the first side surface 76.

[0041] The entire third extending portion 63 is disposed between the first side surface 76 and the second side surface 77. That is, the entire third extending portion 63 is disposed within the range of the second seal groove 72. The second relay portion 65 is capable of contacting the adjacent second side surface 77. In the present embodiment, a gap E2 is provided between the second relay portion 65 and the second side surface 77. When the inner ring 11 and the labyrinth ring 31 move relative to each other in the axial direction, the biasing portion 52 elastically deforms in the axial direction, and the second relay portion 65 comes into contact with the second side surface 77.

[0042] The third link portion 66 is capable of contacting the adjacent first side surface 76. In the present embodiment, a gap E3 is provided between the third link portion 66 and the first side surface 76. When the inner ring 11 and the labyrinth ring 31 move relative to each other in the axial direction, the biasing portion 52 elastically deforms in the axial direction, and the third link portion 66 comes into contact with the first side surface 76. The side surface 64s of the first relay portion 64, the side surface 65s of the second relay portion 65, and the side surface 66s of the third relay portion 66 have planar shapes that are parallel to the adjacent side surface (the first side surface 76 or the second side surface 77) of the second seal groove 72. Each of the relay portions 64, 65, 66 of the oil seal 33 can come into surface contact with the side surface (the first side surface 76 or the second side surface 77) of the second seal groove 72.

[0043] 3 , the entire third extension portion 63 may be disposed between the first side surface 76 and the second side surface 77, while a portion of the third extension portion 63 may be disposed between the first side surface 76 and the second side surface 77. Furthermore, the entire third extension portion 63 may be disposed outside the second seal groove 72. In this case, it is sufficient that at least a portion of the second extension portion 62 is disposed between the first side surface 76 and the second side surface 77.

[0044] [Modification of oil seal 33] FIG. 4 is a cross-sectional view showing a modified example of the oil seal 33. The second seal groove 72 is the same as the second seal groove 72 of the embodiment shown in FIG. 3. Like the oil seal 33 of the embodiment shown in FIG. 3, the oil seal 33 shown in FIG. 4 has a fixed portion 51, a biasing portion 52, a first lip portion 53, and a second lip portion 54. The fixed portion 51 is provided along the groove bottom surface 78. The lip portion 55 contacts the inner circumferential surface 31d of the labyrinth ring 31. The biasing portion 52 is provided between the fixed portion 51 and the lip portion 55.

[0045] The fixed portion 51 has a cylindrical shape. The oil seal 33 shown in Fig. 4 has a ring-shaped spring 70 that presses the fixed portion 51 against the groove bottom surface 78. The oil seal 33 shown in Fig. 4 differs from the oil seal 33 shown in Fig. 3 in that it has the spring 70. The spring 70 prevents the oil seal 33 from rotating relative to the inner ring 11. Note that instead of the spring 70, a configuration using the protrusion 56 and hole 57 shown in Fig. 3 may be used.

[0046] The biasing portion 52 in the form shown in Fig. 4 differs from the biasing portion 52 in the form shown in Fig. 3. The biasing portion 52 in the form shown in Fig. 4 has a first extending portion 61 and a second extending portion 62, and does not have the third extending portion 63 of the biasing portion 52 in the form shown in Fig. 3. The biasing portion 52 of the oil seal 33 shown in Fig. 4 will be described. Note that the reference numerals of the components of the oil seal 33 shown in Fig. 4 that have the same configuration as the oil seal 33 shown in Fig. 3 are the same as the reference numerals of the components of the oil seal 33 shown in Fig. 3.

[0047] The first extending portion 61 is a portion that extends radially outward from the fixed portion 51 and toward a first axial side (left side in FIG. 4). The first extending portion 61 extends from a portion including the end portion 51b on the second axial side (right side in FIG. 4) of the fixed portion 51. A gap e1 is provided in the radial direction between a first relay portion 64 that is a radially outer portion of the first extending portion 61 and the end portion 51a on the first axial side (left side in FIG. 4) of the fixed portion 51.

[0048] The second extending portion 62 extends radially outward from the first relay portion 64 and toward a second axial side (the right side in FIG. 4 ). A gap e2 is provided radially between a second relay portion 65, which is the radially outer portion of the second extending portion 62, and an end portion 61a on the second axial side (the right side in FIG. 4 ) of the first extending portion 61. The lip portion 55 extends from the second relay portion 65 of the second extending portion 62 toward the labyrinth ring 31.

[0049] The entire first extending portion 61 and the entire second extending portion 62 are disposed between the first side surface 76 and the second side surface 77. That is, the entire first extending portion 61 and the entire second extending portion 62 are disposed within the range of the second seal groove 72. The first relay portion 64 is capable of contacting the adjacent second side surface 77. In the present embodiment, a gap E4 is provided between the first relay portion 64 and the second side surface 77. When the inner ring 11 and the labyrinth ring 31 move relative to each other in the axial direction, the biasing portion 52 elastically deforms in the axial direction, and the first relay portion 64 comes into contact with the second side surface 77.

[0050] The second relay portion 65 is capable of contacting the adjacent first side surface 76. In the present embodiment, a gap E5 is provided between the second relay portion 65 and the first side surface 76. When the inner ring 11 and the labyrinth ring 31 move relative to each other in the axial direction, the biasing portion 52 elastically deforms in the axial direction, and the second relay portion 65 comes into contact with the first side surface 76.

[0051] In the form shown in Figure 4, the entire second extension portion 62 is positioned between the first side surface 76 and the second side surface 77, while a portion of the second extension portion 62 may be positioned between the first side surface 76 and the second side surface 77.

[0052] [Regarding each embodiment of the rolling bearing device 10] As described above, the rolling bearing device 10 includes the oil seal 33 that is attached to the inner ring 11 and makes sliding contact with the labyrinth ring 31. Each type of oil seal 33 has a fixed portion 51 that is provided along the groove bottom surface 78, a lip portion 55 that contacts the labyrinth ring 31, and a biasing portion 52 that is provided between the fixed portion 51 and the lip portion 55. The biasing portion 52 has a first extending portion 61 and a second extending portion 62.

[0053] The first extending portion 61 extends radially outward from the fixed portion 51 and toward a first side in the axial direction. The second extending portion 62 extends radially outward from a first relay portion 64, which is a radially outer portion of the first extending portion 61, and toward a second side in the axial direction. The entire first extending portion 61 and at least a part of the second extending portion 62 are provided between the first side surface 76 and the second side surface 77. The first relay portion 64 is capable of contacting the side surface adjacent to the first relay portion 64, of the first side surface 76 and the second side surface 77.

[0054] In the rolling bearing device 10 equipped with the oil seal 33 of each of the above embodiments, the oil seal 33 is interposed between the groove bottom surface 78 and the labyrinth ring 31 in a state where it is elastically compressed and deformed in the radial direction. 52 The lip portion 55 follows and comes into contact with the labyrinth ring 31 due to the elastic compressive deformation and elastic restoring force of the biasing portion. 52 Since the first extension portion 61 and the second extension portion 62 of the oil seal 33 are elastically deformable, the oil seal 33 as a whole is prone to elastic deformation in the radial direction, and the rigidity of the oil seal 33 decreases. In other words, the flexibility of the oil seal 33 in the radial direction increases.

[0055] As a result, even if the gap between the groove bottom surface 78 and the inner peripheral surface 31d of the labyrinth ring 31 is narrow in part of the circumferential direction, the lip portion 55 is less likely to be crushed unevenly. Therefore, the lip portion 55 can contact the labyrinth ring 31 with a desired interference.

[0056] As shown in Figures 3 and 4, in a cross section including the central axis L1, the first extension portion 61 and the second extension portion 62 each extend linearly and intersect at an acute angle. In the case of the oil seal 33 shown in Figure 3, the third extension portion 63 also extends linearly and intersects the second extension portion 62 and the third extension portion 63 at an acute angle. This configuration allows the radial dimension of the oil seal 33 to be reduced and makes it easier for the oil seal 33 to elastically deform in the radial direction. In other words, the oil seal 33 becomes even more flexible.

[0057] 5 has a fixed portion 97 and a lip portion 98 made of rubber, as well as two arc members 100 made of metal and embedded in the fixed portion 97. The two arc members 100 are embedded in the fixed portion 97 at a distance from each other in the circumferential direction. 3 and 4 does not have the two metal arc members 100 embedded in the rubber portion, and therefore the oil seal 33 is prone to elastic deformation in the radial direction.

[0058] Even if the biasing portion 52 is displaced in the axial direction in conjunction with the elastic deformation in the radial direction, the first relay portion 64 can contact the side surface (the first side surface 76 or the second side surface 77) of the second seal groove 72. 72 The position of the oil seal 33 is restricted by the side surfaces, and the overall posture of the oil seal 33 is unlikely to be distorted. Therefore, the lip portion 55 can contact the labyrinth ring 31 while maintaining the desired interference.

[0059] If there is no gap between the first relay portion 64 and the side surface (first side surface 76 or second side surface 77) adjacent to the first relay portion 64 and the axial width dimension of the first extending portion 61 is the same as or larger than the axial dimension of the second seal groove 72, the biasing portion 52 may be constrained by the side surface. In this case, it becomes difficult for the biasing portion 52 to flexibly and elastically deform in the radial direction and cause the lip portion 55 to follow the labyrinth ring 31.

[0060] 3 and 4, however, a gap is provided between the first relay portion 64 and the side surface adjacent to the first relay portion 64. When the inner ring 11 and the labyrinth ring 31 move relative to each other in the axial direction, the first relay portion 64 comes into contact with the side surface. Due to the provision of such a gap, the biasing portion 52 is less likely to be restrained by the side surface, and the lip portion 55 can easily follow the labyrinth ring 31, so that the sealing performance is not reduced.

[0061] 3, the biasing portion 52 has a third extending portion 63. The third extending portion 63 extends radially outward and axially toward the first side from a second relay portion 65, which is the radially outer portion of the second extending portion 62. This configuration allows the oil seal 33 to increase the range over which it can elastically deform in the radial direction.

[0062] 〔others〕 The fixed portion 51 of the oil seal 33 may have a gap between the first side surface 76 and the second side surface 77 of the second seal groove 72, but the fixed portion 51 may be provided in contact with both the first side surface 76 and the second side surface 77 on both sides in the axial direction. In this case, the fixed portion 51 has a function of preventing rotation of the oil seal 33. The shape of the lip portion 55 can vary and may be other than that shown.

[0063] 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. [Explanation of symbols]

[0064] 3 Pestle-shaped roll 4 Small diameter shaft 5 Large diameter section 10. Rolling bearing device 11 Inner Circle 11c Inner raceway 12 Paddlewheel device Around 13 14 Axle box 15 outer ring 15c outer raceway 31 Labyrinth Ring 32 Gasket 33 Oil seal 51 Fixed part 52 energizing section 53 First lip 54 Second lip 55 Lip 61 First extension 62 Second extension 63 Third Extension 64 First Relay Section 65 Second relay station 66 Third Relay Section 71 First seal groove 72 Second seal groove 76 First Aspect 77 The Second Aspect 78 Groove bottom surface E1, E2, E3, E4, E5 gap

Claims

1. A pestle-shaped roll; Axle boxes and an inner ring that rotates integrally with the pestle-shaped roll and has an inner ring raceway; an outer ring having an outer ring raceway opposite 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 face radially 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 second 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 oil seal is a fixing portion provided along the bottom surface of the groove; a lip portion that contacts the labyrinth ring; a biasing portion provided between the fixing portion and the lip portion, The biasing portion is a first extension portion extending radially outward from the fixing portion and to a first side in the axial direction; a second extension portion extending radially outward from a relay portion that is a radially outer portion of the first extension portion and toward a second side in the axial direction, the entirety of the first extending portion and at least a part of the second extending portion are provided between the first side surface and the second side surface, and the relay portion is capable of contacting the side surface of the first side surface and the second side surface that is adjacent to the relay portion; Rolling bearing device.

2. 2. The rolling bearing device according to claim 1, wherein a gap is provided between the relay portion and a side surface adjacent to the relay portion, and when the inner ring and the labyrinth ring move relative to each other in the axial direction, the relay portion and the side surface come into contact with each other.

3. the biasing portion has a third extension portion extending radially outward from a second relay portion that is a radially outer portion of the second extension portion and toward a first side in the axial direction, 3. The rolling bearing device according to claim 1, wherein the lip portion extends from a radially outer portion of the third extension portion toward the labyrinth ring.

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