Tapered roller bearing

Abstract

To provide a tapered roller bearing capable of improving moldability and lubricity of a segment retainer.SOLUTION: A tapered roller bearing includes inner and outer rings, a tapered roller 15, and a retainer 17 for holding the tapered roller 15, and the retainer 17 has a plurality of retainer segments 20 divided and connected in a circumferential direction. The retainer segment 20 includes a large diameter side arc-shaped portion 22 and a small diameter side arc-shaped portion 21 extending in the circumferential direction, and a plurality of pillars 23 connecting the large diameter side and small diameter side arc-shaped portions 22, 21. A dropping-out prevention member 32 for preventing the tapered roller 15 stored in a pocket 16 from dropping out to an outside diameter side is detachably provided on the retainer segment 20. The dropping-out prevention member 32 includes a pillar-like portion 32a which comes into contact with an outside diameter surface of the tapered roller 15, a segment engagement portion 32c which is engaged with a large diameter-side side surface 22b and an inside diameter surface of the large diameter side arc-shaped portion 22, and a beam portion 32e which connects the pillar-like portion 32a and the segment engagement portion 32c at different circumferential positions.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a tapered roller bearing for use as the main bearing of a wind turbine generator or a tapered roller bearing for use in industrial machinery, and in particular to a large tapered roller bearing with an outer diameter exceeding 1 m. [Background technology]

[0002] Tapered roller bearings generally use cages made of steel plate. Steel plate cages are manufactured, for example, by pressing, but for large cages with an outer diameter exceeding 1 m, pressing is difficult due to equipment limitations. On the other hand, cages manufactured by cutting out the material are significantly more expensive than pressed products and also result in greater waste in terms of material loss. For this reason, in order to reduce costs, a segmented cage has been proposed in which multiple cage segments are molded by resin injection molding and then assembled together (for example, Patent Document 1).

[0003] In the case of such a segment cage, for example, when a customer installs a single-row tapered roller bearing into a wind turbine, there is a process in which the inner ring assembly is handled with the small end face facing downwards. At this time, the segment cage is connected with a connecting member such as a wire to prevent the rollers from falling out of the cage. Furthermore, as shown in Figure 20, a method has been devised in which anti-fall-out members 100 are used to prevent the rollers inserted into pockets 16 from falling out to the outer diameter side, thereby allowing the inner ring assembly to be handled without being scattered (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4342512 [Patent Document 2] Japanese Patent Application Publication No. 2022-179448 Summary of the Invention [Problem to be solved by the invention]

[0005] In the conventional invention, it was necessary to provide protrusions with holes for inserting the anti-detachment members on the outer and inner diameter surfaces of the large-diameter arc-shaped portion. Because these holes face in a different direction from the segment pockets, the mold structure used for injection molding becomes complicated, resulting in poor moldability. Furthermore, there was concern that the protrusions would scrape out a large amount of lubricant during bearing operation, resulting in poor lubrication.

[0006] An object of the present invention is to provide a tapered roller bearing that can improve the formability and lubrication of a segment cage. [Means for solving the problem]

[0007] The tapered roller bearing of the present invention comprises an inner ring, an outer ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and a cage that holds the tapered rollers, the cage having a plurality of cage segments that are circumferentially divided and connected together, and the cage segments have a plurality of pockets that are arranged in the circumferential direction and that house the tapered rollers, the retainer segment has a large diameter side arcuate portion and a small diameter side arcuate portion extending in the circumferential direction, and a plurality of column portions connecting these large diameter side and small diameter side arcuate portions, and the pocket is defined by the large diameter side arcuate portion, the small diameter side arcuate portion, and the column portions, A tapered roller bearing is provided with a fall-out prevention member that prevents the tapered rollers housed in the pockets from falling out to the outer diameter side, and is detachably attached to the cage segment, the fall-out prevention member having a columnar portion that contacts the outer diameter surface of the tapered roller, a segment engaging portion that engages with the large diameter side side surface and inner diameter surface of the large diameter side arc-shaped portion, and a beam portion that connects the columnar portion and segment engaging portion at different circumferential positions.

[0008] With this configuration, when assembling the tapered roller bearing, the columnar portions and segment engaging portions of the capacitive element can limit radial, circumferential, and axial movement of the capacitive element relative to the cage segments. This eliminates the need to provide protrusions on the outer diameter surfaces of the arc-shaped portions of the cage segments through which the capacitive element can be inserted, and the formability and lubrication of the segment cage can be improved compared to conventional structures. The anti-disengagement member has beam portions that connect the columnar portions and segment engaging portions at different circumferential positions. Therefore, when tying together multiple cage segments with a connecting member such as a wire, it is possible to ensure circumferential working space for providing fastening portions or fastening members that fasten the ends of the connecting member. Because the columnar portions and segment engaging portions are located at different circumferential positions by the beam portions, it is also possible to ensure working space for removing the fastening portions or fastening members after assembly of the tapered roller bearing is complete. Therefore, it is possible to ensure ease of assembly equivalent to that of conventional structures.

[0009] The retainer segment may have a pocket having a first guide claw extending from the column portion toward the inner diameter side, and a pocket having a second guide claw extending from the column portion toward the outer diameter side, and the anti-fall-out member may prevent the tapered roller housed in the pocket having the first guide claw from falling out toward the outer diameter side.

[0010] In this case, tapered rollers housed in pockets into which second guide claws extend on the outer diameter side of each cage segment can be prevented from falling out by the second guide claws. Tapered rollers housed in pockets having first guide claws extending on the inner diameter side can be prevented from falling out by the anti-fall-out members. Because the cage is guided by the tapered rollers alone during operation due to the first and second guide claws, roller guidance can be achieved.

[0011] The beam portion may be disposed on the outer diameter surface of the large-diameter arc-shaped portion. In this case, a large working space can be secured facing the large-diameter side surface of the large-diameter arc-shaped portion of the retainer segment. This reliably improves the assembly of the segment retainer and reduces the number of assembly steps compared to conventional structures.

[0012] The plurality of cage segments may be connected by a detachable connecting member, and the anti-disengagement member may have a guide portion with which the connecting member is detachably engaged. In this case, an inner ring assembly including an inner ring, tapered rollers, and a cage is assembled by connecting the plurality of cage segments and the anti-disengagement member by the connecting member. When this inner ring assembly is fitted to the outer ring, even if the inner ring assembly is inverted so that the small diameter side faces downward, the annularly arranged cage segments will not separate because their outer peripheral sides are connected by the connecting member. The guide portion may be an insertion hole through which the connecting member is inserted, or an engagement groove that the connecting member is engaged in. With this configuration, the retainer segments and each fall-off prevention member can be easily integrated by the connecting member.

[0013] The cage segments may include a plurality of protrusions each including an engaging portion with which the connecting member is detachably engaged, in which case the cage segments and each of the fall-off prevention members can be easily integrated by the connecting member.

[0014] Both ends of the connecting member may be connected by a fastening portion or a fastening member. With this configuration, the connecting member is easy to handle.

[0015] The fastening portion or fastening member may be disposed between any one of the plurality of protrusions on the cage segment and another protrusion, which can more reliably ensure a working space for disposing the fastening portion or fastening member.

[0016] The cage segments may be made of polyetheretherketone blended with carbon fiber or polyetheretherketone blended with glass fiber. Because carbon fiber or glass fiber is fibrous, it can effectively reduce the thermal expansion coefficient. Therefore, it is possible to prevent the circumferential gap between the cage segments from becoming zero when the cage segments expand. [Effects of the Invention]

[0017] The tapered roller bearing of the present invention comprises an inner ring, an outer ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and a cage that holds the tapered rollers, the cage having a plurality of cage segments that are divided and connected in the circumferential direction, the cage segments having a plurality of pockets that are lined up in the circumferential direction and that house the tapered rollers, and the cage segments having a large diameter side arc-shaped portion and a small diameter side arc-shaped portion that extend in the circumferential direction, and a plurality of pillar portions that connect these large diameter side and small diameter side arc-shaped portions. In a tapered roller bearing in which the pockets are formed by the large diameter side arc-shaped portion, the small diameter side arc-shaped portion and the columnar portion, a drop-out prevention member that prevents the tapered rollers housed in the pockets from falling out to the outer diameter side is detachably attached to the cage segment, and the drop-out prevention member has a columnar portion that contacts the outer diameter surface of the tapered roller, a segment engaging portion that engages with the large diameter side surface and inner diameter surface of the large diameter side arc-shaped portion, and beam portions that connect the columnar portion and the segment engaging portion at different circumferential positions. This improves the formability and lubrication of the segment cage. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view showing a tapered roller bearing according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a front view of the inner ring assembly of the tapered roller bearing as viewed from the axial direction. [Figure 3] FIG. [Figure 4] 3 is a cross-sectional view showing a retainer segment of the retainer of the tapered roller bearing. FIG. [Figure 5] FIG. 4 is a plan view of the retainer segment as viewed from the radially outer side. [Figure 6] FIG. [Figure 7] FIG. 4 is a perspective view of a fall-off prevention member of the inner ring assembly. [Figure 8] FIG. 10 is a perspective view showing a modified example of the fall-off prevention member. [Figure 9] FIG. 10 is a perspective view showing another modified example of the fall-off prevention member. [Figure 10]FIG. 10 is a schematic diagram showing the relationship between the tapered rollers and the large rib portion of the inner ring when the tapered rollers are arranged on the inner ring with the large end face of the inner ring facing downwards. [Figure 11] FIG. 4 is a perspective view showing a state in which the tapered roller is being inserted into a cage segment. [Figure 12] FIG. 4 is a perspective view showing a state in which the cage segment is being inserted into an inner ring. [Figure 13] FIG. 4 is a cross-sectional view showing the state in which the cage segment is being inserted into an inner ring. [Figure 14] FIG. 10 is a perspective view showing a state in which a fall-off prevention member is inserted into a cage segment. [Figure 15] FIG. 10 is a perspective view showing a state in which a connecting member is attached to an inner ring assembly. [Figure 16] FIG. 2 is a schematic diagram showing the rotating state of tapered rollers arranged on the raceway surface of the inner ring. [Figure 17] 10 is a schematic diagram showing the relationship between the height of the small rib portion of the inner ring and the tapered roller when the tapered roller arranged on the raceway surface of the inner ring is rotated. FIG. [Figure 18] FIG. 4 is a cross-sectional view showing a state in which the inner ring assembly is being assembled into the outer ring. [Figure 19] FIG. 4 is a cross-sectional view showing the state in which the inner ring assembly is assembled into the outer ring. [Figure 20] FIG. 10 is a perspective view of a conventional retainer segment. DETAILED DESCRIPTION OF THE INVENTION

[0019] [First embodiment] A tapered roller bearing according to an embodiment of the present invention will be described with reference to FIGS. The tapered roller bearing 1 shown in Fig. 1 is a large tapered roller bearing used, for example, to support the main shaft of a wind turbine generator. In the case of such a tapered roller bearing 1, the average diameter of the tapered rollers 15 is 40 mm or more, and the outer diameter of the bearing is 1 m or more. However, the use of the tapered roller bearing 1 is not limited to this.

[0020] In the following description, the direction of the bearing center axis AX is referred to as the "axial direction," the direction perpendicular to the bearing center axis AX is referred to as the "radial direction," and the circumferential direction around the bearing center axis AX is referred to as the "circumferential direction." The side toward the bearing center axis AX is referred to as the "inner diameter side," and the side away from the bearing center axis AX is referred to as the "outer diameter side." Furthermore, the axial direction in which the diameter of the raceway surface 14 of the outer ring 12 decreases is referred to as the "small diameter side," and the direction in which the diameter of the raceway surface 14 increases is referred to as the "large diameter side."

[0021] The tapered roller bearing 1 comprises an inner ring 11, an outer ring 12, a plurality of tapered rollers 15 interposed between the inner and outer rings 11, 12, and a cage 17 that holds the tapered rollers 15 at regular intervals. The cage 17 has pockets 16 that open in the radial direction, and the tapered rollers 15 are held in these pockets 16.

[0022] The outer ring 12 has, on its inner periphery, a raceway surface 14 on which the tapered rollers 15 roll. The inner ring 11 has, on its outer periphery, a raceway surface 13 on which the tapered rollers 15 roll, and, on either side of this raceway surface 13 in the axial direction, a large rib portion 19 and a small rib portion 18 with which the end faces of the tapered rollers 15 come into contact.

[0023] FIG. 2 is a front view of the inner ring assembly As, which is made up of the inner ring 11, a cage 17, and tapered rollers 15, as viewed from the axial direction. As shown in the figure, the cage 17 is a segment cage having a plurality of cage segments 20 that are divided and connected in the circumferential direction. More specifically, the plurality of cage segments 20 are connected by connecting members 25 (FIG. 1), which will be described later, to form the cage 17. In this embodiment, the cage segments 20 are made of resin. More specifically, the cage segments 20 are made of, for example, polyetheretherketone blended with carbon fiber or polyetheretherketone blended with glass fiber. However, the material of the cage segments 20 is not limited to these.

[0024] <Cage segment> FIG. 3 is a perspective view of the inner ring assembly As, FIG. 4 is a cross-sectional view of the cage segment 20, FIG. 5 is a plan view of the cage segment 20 as seen from the radially outer side, and FIG. 6 is a perspective view of the cage segment 20. Note that FIG. 3 shows only one cage segment 20. The cage segment 20 has a plurality of circumferentially arranged pockets 16 that house tapered rollers 15. In the following description, the cage segment 20 may be simply referred to as the "segment 20."

[0025] 5, the segment 20 has a large-diameter side arc-shaped portion 22 and a small-diameter side arc-shaped portion 21 extending in the circumferential direction, and a plurality of pillar portions 23 connecting these large-diameter side and small-diameter side arc-shaped portions 22, 21. In other words, the small-diameter side arc-shaped portion 21 and the large-diameter side arc-shaped portion 22 face each other at a predetermined distance, and the plurality of pillar portions 23 are provided between the small-diameter side arc-shaped portion 21 and the large-diameter side arc-shaped portion 22.

[0026] Pockets 16 that accommodate tapered rollers 15 (FIG. 4) are formed by the space surrounded by two adjacent pillar portions 23, 23, the small diameter side arc-shaped portion 21, and the large diameter side arc-shaped portion 22. In this embodiment, four pillar portions 23 are provided in one segment 20, and three pockets 16 are provided lined up in the circumferential direction. However, the number of pockets 16 is not limited to this, and it is sufficient that three or more pockets are provided in one segment 20 in the circumferential direction.

[0027] As shown in Figure 4, of the three pockets 16, the circumferentially central pocket 16 has a first guide claw 24a extending from the pillar portion 23 toward the inner diameter side. The pockets 16, 16 at both ends in the circumferential direction have second guide claws 24b extending from the pillar portion 23 toward the outer diameter side. The first guide claw 24a prevents the tapered rollers 15 from slipping out (falling off) toward the inner diameter side, and the second guide claw 24b prevents the tapered rollers 15 from slipping out (falling off) toward the outer diameter side.

[0028] Roller guide surfaces 24aa, 24ba, which are the inner peripheral surfaces of first and second guide claws 24a, 24b, have a concave shape that curves along the shape of tapered rollers 15. These guide claws 24a, 24b allow cage 17 to be guided only by tapered rollers 15 during operation. In other words, the tapered roller bearing of this embodiment can achieve roller guiding.

[0029] The tapered rollers 15 can be inserted into the pockets 16, 16 at both circumferential ends from the inner diameter side of the segment 20. The second guide claws 24b prevent the tapered rollers 15 from slipping out to the outer diameter side. Furthermore, in the state of the inner ring assembly As in Figure 3, the raceway surface 13 of the inner ring 11 is located on the inner diameter side, so the tapered rollers 15 do not slip out to the inner diameter side either.

[0030] As shown in Fig. 4, tapered rollers 15 can be inserted from the outer diameter side into pocket 16 at the circumferential center. In the state of inner ring assembly As shown in Fig. 3, the raceway surface 13 of the inner ring is located on the inner diameter side, so tapered rollers 15 do not slip out to the inner diameter side, but there is a risk that tapered rollers 15 housed in pocket 16 at the circumferential center shown in Fig. 4 may fall out to the outer diameter side. In this embodiment, as shown in Fig. 3, anti-fall-out members 32 are provided along the outer diameter surface 23a of one pillar portion 23, the outer diameter surface 22a of the large diameter side arc-shaped portion 22, and the like that make up pocket 16 at the circumferential center.

[0031] <Fall prevention parts> The fall-off prevention member 32 prevents the tapered rollers 15 housed in the pockets 16 from falling outwardly. In other words, the fall-off prevention member 32 prevents the tapered rollers 15 housed in the pockets 16 having the first guide claws 24a (FIG. 4) from falling outwardly. The fall-off prevention member 32 is detachably provided on the segment 20. As shown in FIG. 5, the fall-off prevention member 32 can be inserted and removed from the inner ring large end face side along the second guide claws 24b extending outwardly of the adjacent pockets 16. The fall-off prevention member 32 is made of, for example, resin or metal. However, the material of the fall-off prevention member 32 is not limited to these.

[0032] 6 and 7, the fall-off prevention member 32 has a pillar portion 32a, a segment engaging portion 32c, a beam portion 32e, and a guide portion 32f, which are integrally formed. The term "integrally formed" means that the pillar portion 32a, the segment engaging portion 32c, the beam portion 32e, and the guide portion 32f are not formed by combining multiple elements, but are formed as part or the whole of a single object from a single material by, for example, molding with a mold or machining.

[0033] 3 and 6 , the columnar portion 32a extends along the outer diameter surface of the segment 20 and comes into contact with the outer diameter surface of the tapered roller 15. Specifically, the columnar portion 32a extends along the outer diameter surface 22a of the large diameter side arcuate portion 22 and the outer diameter surface 23a of the columnar portion 23. The columnar portion 32a comes into contact with the tapered roller 15 to prevent the tapered roller 15 from falling off. In this embodiment, the contact surface 32aa of the columnar portion 32a with the tapered roller 15 has a concave shape that is curved along the outer shape of the tapered roller 15.

[0034] 6 and 7, the segment engaging portion 32c is a generally concave portion that extends along the outer diameter surface 22a, the large diameter side surface 22b, and the inner diameter surface 22c of the segment 20, and engages with the outer diameter surface 22a, the large diameter side surface 22b, and the inner diameter surface 22c of the segment 20. The portion 32cb of the segment engaging portion 32c that engages with the inner diameter surface 22c is a claw-shaped portion that extends a predetermined length from the main body portion 32ca of the segment engaging portion 32c (the portion that extends along the large diameter side surface 22b) to the smaller diameter side.

[0035] The segment engaging portion 32c comes into contact with the outer diameter surface 22a, the large diameter side surface 22b, and the inner diameter surface 22c of the segment 20, thereby restricting the radial movement of the stopper member 32.

[0036] The columnar portion 32a contacts the outer diameter surface of the tapered roller 15 (FIG. 3) and the outer diameter surface of the guide claw 24bb, and the segment engaging portion 32c or the guide portion 32f contacts a later-described large-diameter side protruding portion 26 of the segment 20. Thereby, the circumferential movement of the anti-drop member 32 is restricted. When the segment engaging portion 32c contacts the large-diameter side side surface 22b and the guide portion 32f contacts the connecting member 25 (FIG. 15), the axial movement of the anti-drop member 32 is restricted.

[0037] As shown in FIGS. 3 and 7, the beam portion 32e connects the columnar portion 32a and the segment engaging portion 32c at different circumferential positions. The beam portion 32e is disposed on the outer diameter surface 22a of the large-diameter side arcuate portion 22. The circumferential length of the beam portion 32e is appropriately set according to the circumferential position of the columnar portion 32a with respect to the segment 20, the circumferential position of the large-diameter side protruding portion 26 of the segment 20, and the like.

[0038] A later-described connecting member 25 (FIG. 15) is detachably engaged with the guide portion 32f. Of the anti-drop member 32, the guide portion 32f is provided on the opposite side of the surface of the main body portion 32ca of the segment engaging portion 32c that contacts the segment 20. The guide portion 32f in this example is a groove forming portion that forms a groove 35 opening to the radially outer side. The guide portion 32f is not limited to the shape of this groove forming portion. For example, as in the modification of FIG. 8, the guide portion 32f may be an insertion hole forming portion that forms an insertion hole 35A through which the connecting member 25 is inserted.

[0039] As in the modification of FIG. 9, the width W1 of the entrance of the guide portion 32f, which is a groove forming portion, may be formed smaller than the width W2 of the connecting member 25. The groove width W3 of the engaging groove (guide portion) 32f other than the entrance is larger than the width W2 of the connecting member 25 (W1 < W2 < W3). In this case, the guide portion 32f is elastically deformed, and the connecting member 25 is inserted into the engaging groove (guide portion) 32f. Therefore, it is suppressed that the connecting member 25 comes out of the engaging groove (guide portion) 32f during assembly.

[0040] As shown in Fig. 6, large diameter side protrusions (protrusions) 26, 26 are provided on both end sides of the large diameter side surface 22b of the large diameter side arc-shaped portion 22 of the cage segment 20. As shown in Fig. 5, these multiple large diameter side protrusions 26, 26 protrude a predetermined length in the axial direction from the large diameter side surface 22b of the large diameter side arc-shaped portion 22. Each large diameter side protrusion 26 has an engagement portion 27 with which the connecting member 25 is detachably engaged. In this embodiment, the engagement portion 27 is an engagement groove into which the connecting member 25 is fitted.

[0041] 6 and 15, the large diameter side protrusion 26 is positioned so as not to interfere with the fall-off prevention member 32. The large diameter side protrusion 26 and the fall-off prevention member 32 are positioned side by side in the circumferential direction, and the engagement portion 27 of the large diameter side protrusion 26 is connected to the groove 35 (FIG. 7) of the guide portion 32f. The cage segments 20 and the fall-off prevention members 32 are connected by engaging and fastening the connecting member 25 with the engagement portion 27 and the guide groove of the guide portion 32f.

[0042] <About connecting parts, etc.> 15, multiple segments 20 are connected by detachable connecting members 25. The connecting members 25 are detachable from the segments 20 and the fall-off prevention members 32, and prevent the annularly arranged segment holders 17 from coming apart, i.e., scattering. The connecting members 25 are, for example, wires. However, the connecting members 25 are not limited to wires and may be belts or the like.

[0043] In this embodiment, both ends of the connecting member 25 are connected by a fastening portion or fastening member 42. By arranging the connecting member 25 near the large-diameter-side arc-shaped portion 22 of the cage 17, a gap is secured that allows the connecting member 25 to be removed by hand or with a tool after the bearing is assembled. Furthermore, it is preferable that the fastening portion or fastening member 42 be arranged between any one of the multiple (two in this example) large-diameter-side protrusions 26, 26 in the large-diameter-side arc-shaped portion 22 of the segment 20 and another large-diameter-side protrusion 26.

[0044] The connecting member 25 may be one continuous piece, or may be divided into multiple pieces, with the ends of each connecting member 25 connected by fastening portions or fastening members 42. In this case, it is preferable that the multiple fastening portions and fastening members 42 are arranged at equal intervals on the circumference. The fastening portions or fastening members 42 allow a uniform fastening force to be applied to the entire connecting member 25.

[0045] When a wire is used as the connecting member 25, a hook or a turnbuckle can be used as the fastening member 42. A turnbuckle is preferable because it is detachable, the fastening force does not loosen, and the fastening force is adjustable. When a wire is used as the connecting member 25, a detachable buckle is preferable because the fastening force does not loosen.

[0046] When a turnbuckle is used as the fastening member 42, the fastening member 42 has a body with a female thread, and a male thread provided on the end of the connecting member 25 can be screwed into this body to connect the ends of the connecting members 25. By rotating the body of the turnbuckle 42, tension can be applied to the connecting member 25, and by rotating it in the opposite direction, the binding of both ends of the connecting member 25 can be released.

[0047] <Assembly procedure, effects> First, as shown in Figure 3, the inner ring assembly As is assembled, which integrates the inner ring 11, tapered rollers 15, and cage 17. To assemble the inner ring assembly As, first, with the large end face 11a (Figure 10) of the inner ring 11 facing downwards, the tapered rollers 15 that will fit into pockets 16 other than those at the circumferential center of the segment 20 are lined up on the raceway surface of the inner ring 11.

[0048] If tapered rollers 15 are placed on raceway surface 13 of inner ring 11 with large end face 11a (Figure 10) of inner ring 11 facing downwards, tapered rollers 15 may fall off due to their own weight. To prevent this from happening, as shown in Figure 10, the distance from center axis AX1 of inner ring 11 to the tip of large rib portion 19 is made larger than the distance from center axis AX1 of inner ring 11 to the center of gravity C1 of tapered roller 15.

[0049] In detail, with tapered rollers 15 arranged on raceway surface 13 of inner ring 11 with large end face 11a of inner ring 11 facing downwards, the angle at which large rib portion 19 of inner ring 11 intersects with center axis AX1 of inner ring 11 at right angles is I, the chamfer width at the tip of large rib portion 19 is H, the distance from center axis AX1 of inner ring 11 to center of gravity C1 of tapered roller 15 is y1, and the diameter of large rib portion 19 is J, the following formula (1) is satisfied. (J / 2)-H·cosI>y1 …Formula (1)

[0050] Next, as shown in Figure 11, tapered rollers 15 are inserted into pockets 16 at the circumferential center of the segment 20. In this state, as shown in Figures 12 and 13, the segment 20 is placed over the inner ring 11 on which the tapered rollers 15 are arranged. As a result, the tapered rollers 15 are inserted from the inner diameter side into the pockets 16 at both circumferential ends.

[0051] Next, as shown in Figure 14, in order to prevent the tapered rollers 15 housed in the pockets 16 at the circumferential center of the segment 20 from falling off to the larger diameter side, a fall-off prevention member 32 is inserted from the larger end face side of the inner ring 11 along the outer diameter surfaces of the tapered rollers 15 and the guide claw outer diameter surfaces 24bb adjacent to these outer diameter surfaces.

[0052] 15, the connecting member 25 is engaged with the engaging portion 27 of the large diameter side protrusion 26 on the large diameter side surface 22b of the segment 20 and the guide portion 32f of the fall-off prevention member 32. The ends of the connecting member 25 arranged on the outer diameter side of the segment 20 are fastened with the fastening member 42, and the connecting member 25 is further tightened with the fastening member 42. This integrates the multiple segments 20 arranged in an annular shape. This completes the assembly of the inner ring assembly As.

[0053] After the inner ring assembly As is assembled, it is fitted into the outer ring 12 as shown in Figures 18 and 19. The fitting of the inner ring assembly As into the outer ring 12 can be carried out in an inverted state with the small diameter side of the inner ring assembly As facing downwards. Even in an inverted state, the annularly arranged segments 20 are connected on their outer peripheries by connecting members 25, so the segments 20 will not come apart.

[0054] The tapered rollers 15 inserted into the pockets 16 (Figure 12) at both circumferential ends of each segment 20 are prevented from falling out by the second guide claws 24b (Figure 3) provided on the outer diameter side, and the tapered rollers 15 inserted into the pocket 16 (Figure 11) at the circumferential center are prevented from falling out by the anti-fall-out members 32 (Figure 14). Even when the inner ring assembly As is turned upside down, the tapered rollers 15 are sandwiched between the large rib portion 19 and the small rib portion 18, and the tapered rollers 15 are caught on the small rib portion 18, preventing each segment 20 from falling off.

[0055] When tapered roller 15 is not in contact with large rib portion 19, it rotates in the direction of arrow AR1 around point A on raceway surface 13, as shown in Figure 16. When tapered roller 15 is in contact with large rib portion 19, it rotates in the direction of arrow AR2 around point B on the inner surface of large rib portion 19, as shown in Figure 17.

[0056] When the tapered roller 15 shown in Figure 17 rotates around point B, the small diameter side end face of the tapered roller 15 comes into contact with point C on the side face of the small rib portion 18. This prevents the tapered roller 15 from rotating. Point C is the contact point where the side face of the small rib portion 18 and the small diameter side end face of the tapered roller 15 come into contact when the tapered roller 15 is rotated around the tip of the large rib portion 18 of the inner ring 11. In other words, contact point C is the intersection point between the side face of the small rib portion 18 and the spline curve that traces the trajectory of the corner of the small end face of the tapered roller 15 as the tapered roller 15 rotates.

[0057] In detail, when the retainer segments 20 are connected by the connecting member 25 shown in Figure 18, the diameter of the small rib portion 18 of the inner ring 11 shown in Figure 17 is M, the angle of the small rib portion 18 with respect to a line perpendicular to the center axis AX1 of the inner ring 11 is L, the chamfer width of the tip of the small rib portion 18 is K, and the distance from the contact point C to the center axis AX1 is y3, the following formula (2) is satisfied. (M / 2)-K cosL>y3 …Formula (2)

[0058] After the assembly of the tapered roller bearing 1 shown in Figure 19 is complete, the connecting members 25 and the fall-off prevention members 32 (Figure 15) can be removed by loosening the fastening members 42 (Figure 15). After the tapered roller bearing 1 is assembled, the individual segments 20 will not come apart even if the connecting members 25 and the fall-off prevention members 32 (Figure 15) are removed.

[0059] As described above, according to this embodiment, the connecting member 25 and the fall-off prevention member 32 shown in Fig. 15 are detachable, so that the inner ring assembly As is integrated with the connecting member 25 and the fall-off prevention member 32, and yet the connecting member 25 and the fall-off prevention member 32 can be removed after the bearing is assembled. Also, the cage 17 shown in Fig. 4 is guided only by the tapered rollers 15 during operation by the first and second guide claws 24a, 24b, so roller guiding can be achieved.

[0060] As shown in Fig. 7, the fall-off prevention member 32 has beam portions 32e that connect the columnar portions 32a and the segment engaging portions 32c at different circumferential positions. Therefore, when multiple cage segments 20 are bound together by connecting members 25 such as wires, as shown in Fig. 15, it is possible to ensure a circumferential working space for providing fastening portions or fastening members 42 that fasten the ends of the connecting members 25 together.

[0061] Because the columnar portion 32a and the segment engaging portion 32c are arranged at different circumferential positions by the beam portion 32e, it is also possible to ensure working space for removing the fastening portion or fastening member 42 in Fig. 15 after assembly of the tapered roller bearing is complete. When the beam portion 32e in Fig. 14 is arranged on the outer diameter surface 22a of the large diameter side arc-shaped portion 22, it is possible to ensure a large working space facing the large diameter side surface 22b of the large diameter side arc-shaped portion 22 in the cage segment 20.

[0062] When the retainer segments 20 are made of polyetheretherketone blended with carbon fiber or polyetheretherketone blended with glass fiber, the thermal expansion coefficient can be reduced efficiently, and therefore, the circumferential gap between the segments can be prevented from becoming zero when the retainer segments 20 expand.

[0063] Although the embodiments of the present invention have been described above, the disclosed 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 description, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] DESCRIPTION OF SYMBOLS 1... Tapered roller bearing, 11... Inner ring, 12... Outer ring, 15... Tapered roller, 16... Pocket, 17... Cage, 20... Cage segment, 21... Small diameter side arc-shaped portion, 22... Large diameter side arc-shaped portion, 23... Column portion, 24a... First guide claw, 24b... Second guide claw, 25... Connecting member, 26... Large diameter side protrusion (protrusion), 32... Fall-off prevention member, 32a... Column portion, 32c... Segment engaging portion, 32e... Beam portion, 32f... Guide portion, 42... Fastening member

Claims

1. the bearing comprises an inner ring, an outer ring, a plurality of tapered rollers interposed between the inner ring and the outer ring, and a cage that holds the tapered rollers, the cage having a plurality of cage segments that are circumferentially divided and connected together, and the cage segments having a plurality of pockets that are aligned in the circumferential direction and that house the tapered rollers; the retainer segment has a large diameter side arcuate portion and a small diameter side arcuate portion extending in the circumferential direction, and a plurality of column portions connecting these large diameter side and small diameter side arcuate portions, and the pocket is defined by the large diameter side arcuate portion, the small diameter side arcuate portion, and the column portions, A tapered roller bearing is provided with a fall-out prevention member that prevents the tapered rollers housed in the pockets from falling out to the outer diameter side, and is detachably attached to the cage segment, the fall-out prevention member having a columnar portion that contacts the outer diameter surface of the tapered roller, a segment engaging portion that engages with the large diameter side side surface and inner diameter surface of the large diameter side arc-shaped portion, and a beam portion that connects the columnar portion and segment engaging portion at different circumferential positions.

2. 2. A tapered roller bearing according to claim 1, wherein the retainer segment has a pocket having a first guide claw extending from the column portion toward the inner diameter side, and a pocket having a second guide claw extending from the column portion toward the outer diameter side, and the anti-fall-out member prevents the tapered rollers housed in the pockets having the first guide claws from falling out toward the outer diameter side.

3. 3. A tapered roller bearing according to claim 1, wherein the beam portion is disposed on an outer diameter surface of the large diameter side arcuate portion.

4. 3. A tapered roller bearing according to claim 1, wherein the plurality of retainer segments are connected by a detachable connecting member, and the anti-disengagement member has a guide portion with which the connecting member is detachably engaged.

5. 5. A tapered roller bearing according to claim 4, wherein said cage segments are provided with a plurality of protrusions including engagement portions with which said connecting members are detachably engaged.

6. 6. A tapered roller bearing according to claim 5, wherein both ends of the connecting member are connected by a fastening portion or a fastening member.

7. 7. A tapered roller bearing according to claim 6, wherein the fastening portion or fastening member is disposed between any one of the plurality of protrusions on the retainer segment and another of the plurality of protrusions.

8. 3. A tapered roller bearing according to claim 1, wherein the cage segments are made of polyether ether ketone blended with carbon fiber or polyether ether ketone blended with glass fiber.

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