Tapered roller bearing

Abstract

A tapered roller bearing comprises inner and outer rings, tapered rollers (15), and a retainer (17) for retaining the tapered rollers (15). The retainer (17) has a plurality of retainer segments (20) divided and coupled in the circumferential direction. Each of the retainer segments (20) has a large-diameter-side arc-shaped section (22) and a small-diameter-side arc-shaped section (21) extending in the circumferential direction, and a plurality of column sections (23) connecting the large-diameter-side and small-diameter-side arc-shaped sections (22, 21). A dropout prevention member (32) for preventing a tapered roller (15) accommodated in a pocket (16) from dropping out on the outer diameter side is detachably provided to the retainer segment (20). The dropout prevention member (32) has: a columnar section (32a) that comes into contact with the outer diameter surface of the tapered roller (15); a segment engagement section (32c) that engages with the inner diameter surface and a large-diameter-side lateral surface (22b) of the large-diameter-side arc-shaped section (22); and a beam section (32e) that connects the pillar section (32a) and the segment engagement section (32c) at different positions in the circumferential direction.

Description

tapered roller bearings Related Applications

[0001] This application claims priority from Japanese Patent Application No. 2024-069295, filed April 22, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a tapered roller bearing for use as the main bearing of a wind power generator or a tapered roller bearing for use in industrial machinery, and in particular to a large tapered roller bearing having an outer diameter exceeding 1 m.

[0003] Tapered roller bearings generally use steel plate cages. Steel plate cages are manufactured by, for example, press working, but large cages with an outer diameter exceeding 1 m are difficult to manufacture by press working due to equipment limitations. On the other hand, cages manufactured by cutting are significantly more expensive than pressed products and also result in greater waste in terms of material loss. Therefore, to reduce costs, a segmented cage has been proposed in which multiple cage segments are molded by resin injection molding and then assembled (see, for example, Patent Document 1).

[0004] 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 the pockets 16 from falling out to the outer diameter side, thereby allowing the inner ring assembly to be handled without being scattered (for example, see Patent Document 2).

[0005] Japanese Patent No. 4342512 Japanese Patent Application Laid-Open No. 2022-179448

[0006] 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.

[0007] An object of the present invention is to provide a tapered roller bearing that can improve the formability and lubrication of a segment cage.

[0008] 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, the cage segments having a large diameter side arcuate portion and a small diameter side arcuate portion that extend in the circumferential direction, and a plurality of pillar portions that connect these large diameter side and small diameter side arcuate portions, the pockets being formed by the large diameter side arcuate portion, the small diameter side arcuate portion and the pillar 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.

[0009] According to this configuration, when assembling a tapered roller bearing, the columnar portions and segment engaging portions of the captive member can limit radial, circumferential, and axial movement of the captive member 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 captive member can be inserted, improving the formability and lubrication of the segment cage compared to conventional structures. The captive member has beam portions that connect the columnar portions and segment engaging portions at different circumferential positions. Therefore, when tying and integrating multiple cage segments with connecting members such as wires, it is possible to ensure circumferential working space for providing fastening portions or fastening members that fasten the ends of the connecting members. Because the columnar portions and segment engaging portions are located at different circumferential positions due to the beam portions, working space can also be secured for removing the fastening portions or fastening members after the tapered roller bearing is fully assembled. This ensures ease of assembly equivalent to that of conventional structures.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] The multiple 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 multiple cage segments and the anti-disengagement member with the connecting member. When this inner ring assembly is installed into the outer ring, even if the inner ring assembly is inverted with the small diameter side facing 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 into which the connecting member is engaged. With this configuration, the connecting member makes it easy to integrate the cage segments and each anti-disengagement member.

[0014] 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.

[0015] 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.

[0016] The fastening portion or fastening member may be disposed between any one of the plurality of protrusions on the retainer segment and another protrusion, thereby more reliably securing a working space for disposing the fastening portion or fastening member.

[0017] 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.

[0018] Any combination of at least two features disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims is included in the present invention.

[0019] The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are merely for illustration and explanation, and should not be used to define the scope of the present invention, which is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.

[0020] FIG. 1 is a cross-sectional view showing a tapered roller bearing according to a first embodiment of the present invention. FIG. 2 is a front view of an inner ring assembly of the tapered roller bearing, viewed from the axial direction. FIG. 3 is a perspective view of the inner ring assembly. FIG. 4 is a cross-sectional view of a cage segment of the cage of the tapered roller bearing. FIG. 5 is a plan view of the cage segment, viewed from the radially outer side. FIG. 6 is a perspective view of the cage segment. FIG. 7 is a perspective view of a fall-off prevention member of the inner ring assembly. FIG. 8 is a perspective view showing a modified example of the fall-off prevention member. FIG. 9 is a perspective view showing another modified example of the fall-off prevention member. FIG. 10 is a schematic view 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. FIG. 11 is a perspective view showing the tapered rollers being inserted into the cage segment. FIG. 12 is a cross-sectional view showing the cage segment being inserted into the inner ring. FIG. 13 is a perspective view showing the state where the fall-off prevention member is inserted into the cage segment. 1 is a schematic diagram showing the relationship between the height of a small rib portion of an inner ring and the tapered roller when the tapered roller arranged on the raceway surface of the inner ring is rotated. FIG. 2 is a cross-sectional view showing a state in which an inner ring assembly is being assembled into an outer ring. FIG. 3 is a cross-sectional view showing a state in which an inner ring assembly is being assembled into an outer ring. FIG. 4 is a perspective view of a cage segment of a conventional example.

[0021] [First embodiment] A tapered roller bearing according to an embodiment of the present invention will be described with reference to Figures 1 to 19. The tapered roller bearing 1 shown in Figure 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.

[0022] 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 facing 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 becomes smaller is referred to as the "small diameter side," and the direction in which the diameter of the raceway surface 14 becomes larger is referred to as the "large diameter side."

[0023] 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.

[0024] 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.

[0025] FIG. 2 is a front view of the inner ring assembly As, which is composed of the inner ring 11, the cage 17, and the 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.

[0026] <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."

[0027] 5, each segment 20 has a large-diameter side arcuate portion 22 and a small-diameter side arcuate portion 21 extending in the circumferential direction, and a plurality of pillar portions 23 connecting these large-diameter side arcuate portion 22, 21. In other words, the small-diameter side arcuate portion 21 and the large-diameter side arcuate portion 22 face each other at a predetermined distance, and the plurality of pillar portions 23 bridge between the small-diameter side arcuate portion 21 and the large-diameter side arcuate portion 22.

[0028] Pockets 16 for accommodating tapered rollers 15 ( FIG. 4 ) are formed by the spaces surrounded by two adjacent column portions 23, 23, the small diameter side arc-shaped portion 21, and the large diameter side arc-shaped portion 22. In this embodiment, four column 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.

[0029] 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 OS. The first guide claw 24a prevents the tapered rollers 15 from slipping out (falling off) to the inner diameter side IS, and the second guide claw 24b prevents the tapered rollers 15 from slipping out (falling off) to the outer diameter side OS.

[0030] 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.

[0031] The tapered rollers 15 can be inserted into the pockets 16, 16 at both circumferential ends from the inner diameter side IS of the segment 20. The second guide claws 24b prevent the tapered rollers 15 from slipping out to the outer diameter side OS. Furthermore, in the state of the inner ring assembly As shown in Figure 3, the raceway surface 13 of the inner ring 11 is located on the inner diameter side IS, so the tapered rollers 15 do not slip out to the inner diameter side IS either.

[0032] As shown in Figure 4, tapered rollers 15 can be inserted into the circumferentially central pocket 16 from the outer diameter side OS. In the state of the inner ring assembly As shown in Figure 3, the raceway surface 13 of the inner ring is located on the inner diameter side IS, so the tapered rollers 15 do not slip out onto the inner diameter side IS, but there is a risk that the tapered rollers 15 housed in the circumferentially central pocket 16 shown in Figure 4 may fall out onto the outer diameter side OS. In this embodiment, as shown in Figure 3, anti-fall-out members 32 are provided along the outer diameter surface 23a of one of the pillar portions 23 and the outer diameter surface 22a of the large diameter side arc-shaped portion 22 that constitute the circumferentially central pocket 16.

[0033] <Lock-up prevention member> The lock-up prevention member 32 prevents the tapered rollers 15 housed in the pockets 16 from falling out toward the outer diameter side. In other words, the lock-up prevention member 32 prevents the tapered rollers 15 housed in the pockets 16 having the first guide claws 24a (FIG. 4) from falling out toward the outer diameter side. The lock-up prevention member 32 is detachably provided on the segment 20. As shown in FIG. 5, the lock-up prevention member 32 is insertable and removable from the inner ring large end face side along the second guide claws 24b extending toward the outer diameter side of the adjacent pockets 16. The lock-up prevention member 32 is made of, for example, resin or metal. However, the material of the lock-up prevention member 32 is not limited to these.

[0034] 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.

[0035] 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.

[0036] 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 a main body portion 32ca of the segment engaging portion 32c (the portion that extends along the large diameter side surface 22b) toward the smaller diameter side.

[0037] 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 radial movement of the anti-disengagement member 32.

[0038] The columnar portion 32a contacts the outer diameter surface of the tapered roller 15 (FIG. 3) and the guide claw outer diameter surface 24bb, and the segment engaging portion 32c or the guide portion 32f contacts the large diameter side protrusion 26 (described later) of the segment 20. This restricts circumferential movement of the fall-off prevention member 32. The segment engaging portion 32c contacts the large diameter side surface 22b, and the guide portion 32f contacts the connecting member 25 (FIG. 15), restricting axial movement of the fall-off prevention member 32.

[0039] 3 and 7 , the beam portion 32e connects the columnar portion 32a and the segment engaging portion 32c at mutually different circumferential positions. The beam portion 32e is disposed on the outer diameter surface 22a of the large-diameter-side arc-shaped portion 22. The circumferential length of the beam portion 32e is set appropriately depending on the circumferential position of the columnar portion 32a relative to the segment 20, the circumferential position of the large-diameter-side protruding portion 26 of the segment 20, and other factors.

[0040] The guide portion 32f is detachably engaged with a connecting member 25 (FIG. 15), which will be described later. The guide portion 32f is provided on the main body portion 32ca of the segment engaging portion 32c of the anti-disengagement member 32, on the side opposite to the surface that abuts against the segment 20. The guide portion 32f in this example is a groove forming portion that forms a groove 35 that opens radially outward. The shape of the guide portion 32f is not limited to this groove forming portion. For example, as in the modified example shown in 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.

[0041] As shown in the modified example 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 engagement 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 engagement groove (guide portion) 32f. Therefore, the connecting member 25 is prevented from slipping out of the engagement groove (guide portion) 32f during assembly.

[0042] As shown in Fig. 6, large diameter side protrusions (protrusions) 26, 26 are provided on both ends 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.

[0043] 6 and 15, the large diameter side protrusion 26 is positioned so as not to interfere with the capsulation prevention members 32. The large diameter side protrusion 26 and the capsulation prevention members 32 are positioned side by side in the circumferential direction, and the engaging 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 capsulation prevention members 32 are connected by engaging and fastening the connecting member 25 with the engaging portion 27 and the guide groove of the guide portion 32f.

[0044] <Regarding connecting members, etc.> As shown in Fig. 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.

[0045] In this embodiment, both ends of the connecting member 25 are connected by fastening portions or fastening members 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 portions or fastening members 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.

[0046] The connecting member 25 may be a single 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.

[0047] 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.

[0048] 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.

[0049] <Assembly Procedure, Actions and Effects> First, as shown in Figure 3, an 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.

[0050] If tapered rollers 15 are arranged on raceway surface 13 of inner ring 11 with large end face 11a (Figure 10) of inner ring 11 facing downward, there is a possibility that tapered rollers 15 will fall off due to their own weight. To prevent this from happening, as shown in Figure 10, the distance from central axis AX1 of inner ring 11 to the tip of large rib portion 19 is made larger than the distance from central axis AX1 of inner ring 11 to the center of gravity C1 of tapered roller 15.

[0051] Specifically, with the tapered rollers 15 arranged on the raceway surface 13 of the inner ring 11 with the large end face 11a of the inner ring 11 facing downwards, the angle at which the large rib portion 19 of the inner ring 11 intersects with the center axis AX1 of the inner ring 11 at right angles is I, the chamfer width at the tip of the large rib portion 19 is H, the distance from the center axis AX1 of the inner ring 11 to the center of gravity C1 of the tapered roller 15 is y1, and the diameter of the large rib portion 19 is J, the following formula (1) is satisfied: (J / 2)-H·cosI>y1...formula (1)

[0052] Next, as shown in Figure 11, tapered rollers 15 are inserted into the 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.

[0053] 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 surface of the tapered roller 15 and the guide claw outer diameter surface 24bb adjacent to this outer diameter surface.

[0054] 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 anti-disengagement 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.

[0055] After the inner ring assembly As is assembled, it is fitted to the outer ring 12 as shown in Figures 18 and 19. The fitting of the inner ring assembly As to 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 the connecting members 25, so the segments 20 will not come apart.

[0056] The tapered rollers 15 inserted into the pockets 16 (Fig. 12) at both circumferential ends of each segment 20 are prevented from falling out by second guide claws 24b (Fig. 3) provided on the outer diameter side, and the tapered rollers 15 inserted into the circumferential center pocket 16 (Fig. 11) are prevented from falling out by anti-fall-out members 32 (Fig. 14). Even if the inner ring assembly As is turned over, 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 out.

[0057] When the tapered rollers 15 are not in contact with the large rib portion 19, they rotate in the direction of arrow AR1 around point A on the raceway surface 13, as shown in Figure 16. When the tapered rollers 15 are in contact with the large rib portion 19, they rotate in the direction of arrow AR2 around point B on the inner surface of the large rib portion 19, as shown in Figure 17.

[0058] 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 SP that traces the trajectory of the corner of the small end face of the tapered roller 15 as the tapered roller 15 rotates.

[0059] In detail, in a state where the cage segments 20 are connected by the connecting member 25 shown in Fig. 18, when the diameter of the small rib portion 18 of the inner ring 11 shown in Fig. 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 cos L > y3 ... formula (2)

[0060] 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.

[0061] 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.

[0062] As shown in Fig. 7, the anti-detachment 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.

[0063] 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.

[0064] 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 efficiently reduced, and therefore, the circumferential gap between the segments can be prevented from becoming zero when the retainer segments 20 expand.

[0065] As described above, the preferred embodiment has been described with reference to the drawings, but various additions, modifications, and deletions can be made without departing from the spirit of the present invention. Therefore, such additions, modifications, and deletions are also included in the scope of the present invention.

[0066] 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. A tapered roller bearing comprising 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 circumferentially, the cage segments having a plurality of pockets that are lined up in the circumferential direction and that house the tapered rollers, the cage segments having a large diameter side arcuate portion and a small diameter side arcuate portion that extend circumferentially, and a plurality of pillar portions that connect these large diameter side and small diameter side arcuate portions, the pockets being formed by the large diameter side arcuate portion, the small diameter side arcuate portion and the pillar 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. A tapered roller bearing as described in claim 1, wherein the retainer segment has a pocket with a first guide claw extending from the column portion toward the inner diameter side, and a pocket with 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 with the first guide claws from falling out toward the outer diameter side.

3. A tapered roller bearing according to claim 1 or 2, wherein the beam portion is disposed on the outer diameter surface of the large diameter side arcuate portion.

4. A tapered roller bearing as set forth in claim 1 or claim 2, wherein the plurality of retainer segments are connected by a detachable connecting member, and the anti-fall-out member has a guide portion with which the connecting member is detachably engaged.

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

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

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. A tapered roller bearing according to claim 1 or 2, wherein the cage segments are made of polyetheretherketone blended with carbon fiber or polyetheretherketone blended with glass fiber.

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