Inner ring units and tapered roller bearings

Abstract

The present invention provides an inner ring unit and a tapered roller bearing. The inner ring unit (50) includes an inner ring (3), a plurality of tapered rollers (4) and a retainer (10) having an annular shape. The retainer (10) includes a plurality of retainer rods. The retainer (10) includes a stopper portion, which is arranged to protrude from an axial middle portion of the retainer rod in the circumferential direction of the retainer (10) and is configured to prevent the tapered roller (4) from falling out radially outward by bringing an axial middle portion on the outer peripheral surface of each tapered roller (4) accommodated in a pocket into contact with the stopper portion. The axial middle portion on the outer peripheral surface of the tapered roller (4) is a portion arranged on one axial side and radially outward of the tapered roller (4) relative to the center of gravity of the tapered roller (4). The tapered roller bearing includes an inner ring unit and an outer ring arranged radially outward relative to the inner ring.

Description

Technical Field

[0001] The invention relates to an inner ring unit and a tapered roller bearing. Background Art

[0002] Fig. 9 is a longitudinal sectional view showing a tapered roller bearing 100. The tapered roller bearing 100 includes an inner ring 101, an outer ring 102, a plurality of tapered rollers 103, and a retainer 104 which has an annular shape and retains the tapered rollers 103 at certain intervals in the circumferential direction (for example, refer to Japanese Unexamined Patent Application Publication No. 2013-221592 (JP2013-221592A)).

[0003] The retainer 104 includes: a Fig. 9 The small diameter annular body 105 is arranged on the left side of the other axial side ( Fig. 9 and a plurality of cage rods 107 connecting the annular bodies 105 and 106. The space defined between the annular bodies 105 and 106 and between any two cage rods 107 and 107 adjacent to each other in the circumferential direction is used as a pocket 108 for accommodating each tapered roller 103.

[0004] like Fig. 9 The tapered roller bearing 100 shown in FIG. 1 can be assembled as follows. First, the tapered rollers 103 are accommodated in the respective pockets 108 in the cage 104. The cage 104 includes a tapered roller stopper 107a provided at each end of the cage rod 107 in the axial direction to prevent each tapered roller 103 accommodated in the pocket 108 from falling out of the cage 104 toward the radial outer side. In a state where the tapered rollers 103 are retained in the cage 104 (in the respective pockets 108), the inner ring 101 is brought close to the cage 104 in which the tapered rollers 103 are accommodated along the axial direction from the small diameter side to position the tapered rollers 103 on the inner ring raceway surface 101a of the inner ring 101.

[0005] In the process of positioning the tapered roller 103 on the inner ring raceway surface 101a, the small diameter portion 110 of each tapered roller 103 needs to be displaced toward the radial outside to pass over the top surface rib (hereinafter referred to as small rib) 101b of the inner ring 101. However, the tapered roller stopper 107a restricts the displacement of the small diameter portion 110. The inner ring 101 is axially pressed against the retainer 104, in which the tapered roller 103 is retained in the pocket 108 with a large force by using a press or the like, and when the small diameter portion 110 passes over the small rib 101b, the retainer 104 is deformed (the diameter of the retainer 104 is increased), and the tapered roller 103 is displaced and positioned on the inner ring raceway surface 101a. As a result, an inner ring unit is obtained in which the inner ring 101, the retainer 104 and the tapered roller 103 are integrated. Tapered roller bearing 100 is completed by assembling outer ring 102 to the inner ring unit thus obtained.

[0006] However, as described above, when the small diameter portion 110 of the tapered roller 103 passes over the small rib 101b of the inner ring 101, excessive force is applied to the cage 104. As a result, when the strain caused by the deformation of the cage 104 exceeds the allowable range, the cage 104 may be whitened or plastically deformed, or the cage 104 may be broken. Summary of the invention

[0007] The present invention provides an inner ring unit and a tapered roller bearing, which can reduce the strain caused by the deformation of a cage during assembly.

[0008] The inner ring unit according to the first form of the present invention includes an inner ring, a plurality of tapered rollers and a retainer having an annular shape. The inner ring includes an inner ring raceway surface, a small rib and a bottom rib (hereinafter referred to as a large rib). The inner ring raceway surface is on the outer periphery of the inner ring. The small rib is arranged on one axial side of the inner ring relative to the inner ring raceway surface, and the small rib protrudes toward the radial outside. The large rib is arranged on the other axial side of the inner ring relative to the inner ring raceway surface, and the large rib protrudes toward the radial outside. The plurality of tapered rollers are arranged to roll on the inner ring raceway surface. The retainer includes a small diameter annular body, a large diameter annular body and a plurality of retainer rods. The small diameter annular body is arranged on one axial side of the retainer, and the large diameter annular body is arranged on the other axial side of the retainer. The plurality of retainer rods are configured to connect the small diameter annular body and the large diameter annular body. The retainer is configured to retain the plurality of tapered rollers in corresponding pockets, each pocket being a space defined between the plurality of retainer rods adjacent to each other in the circumferential direction of the retainer between the large-diameter annular body and the small-diameter annular body. The retainer includes a stopper portion, which is provided to protrude in the circumferential direction of the retainer at an axial middle portion of the retainer rod, and the stopper portion is configured to prevent each of the plurality of tapered rollers from falling out toward the radially outer side by bringing an axial middle portion on the outer circumferential surface of the tapered roller retained in the pocket into contact with the stopper portion. The axial middle portion on the outer circumferential surface of the tapered roller is a portion provided on one axial side and radially outer side of the tapered roller relative to the center of gravity of the tapered roller.

[0009] In the process of assembling the inner ring unit, first, the tapered rollers are accommodated in the pockets of the cage, and then the inner ring is brought close to the cage provided with the tapered rollers in the axial direction to assemble the inner ring to the cage provided with the tapered rollers. In the process of assembling the inner ring to the cage provided with the tapered rollers, the small diameter portion of each tapered roller needs to be displaced toward the radial outside and pass over the small rib of the inner ring. With the inner ring unit of the first form of the present invention, when the small diameter portion of the tapered roller passes over the small rib, the tapered roller is prevented from falling out toward the radial outside by bringing the axial middle portion on the outer peripheral surface of the tapered roller into contact with the stopper portion provided on the cage rod of the cage. This presses the inner ring against the cage in the axial direction and deforms the cage. However, since the axial middle portion on the outer peripheral surface of the tapered roller is a portion on one axial side and on the radial outside relative to the center of gravity of the tapered roller, the large diameter portion of the tapered roller swings toward the radial inside, while the small diameter portion of the tapered roller swings toward the radial outside with the stopper portion as a fulcrum. With this configuration, the amount of radially outward displacement required for the small diameter portion of the tapered roller to pass over the small rib can be reduced. Therefore, the small diameter portion of the tapered roller can easily pass over the small rib. Therefore, it is not necessary to press the inner ring against the cage in the axial direction with a large force, and thus the strain caused by the deformation of the cage can be reduced. Therefore, whitening or plastic deformation of the cage and cracks on the cage can be suppressed.

[0010] In the inner ring unit according to the first form, the stopper may have a triangular prism shape in which the axial width gradually decreases as the stopper protrudes from the retaining frame rod in the circumferential direction of the retaining frame, and the first surface constituting the triangular prism shape and disposed on the one axial side relative to the protruding edge of the stopper may be a contact surface that comes into contact with the axial middle portion on the outer peripheral surface of the tapered roller. With the inner ring unit of the first form of the present invention, the axial middle portion on the outer peripheral surface of the tapered roller does not come into contact with the protruding edge of the stopper protruding in the triangular prism shape. This makes it possible to avoid stress concentration on the stopper.

[0011] In the inner ring unit according to the first form of the present invention, a rounded portion may be provided on the radially inner edge of the contact surface. With the inner ring unit according to the first form of the present invention, the axial middle portion on the outer peripheral surface of the tapered roller is brought into contact with the rounded portion at the edge of the contact surface provided on the radial inner side of the stopper. This makes it possible to further avoid stress concentration on the stopper.

[0012] A tapered roller bearing according to a second embodiment of the present invention includes an inner ring unit and an outer ring. The inner ring unit includes an inner ring, a plurality of tapered rollers, and a retainer having an annular shape. The inner ring includes an inner ring raceway surface, a small rib, and a large rib. The inner ring raceway surface is on the outer periphery of the inner ring. The small rib is arranged on one axial side of the inner ring relative to the inner ring raceway surface, and the small rib protrudes toward the radial outer side. The large rib is arranged on the other axial side of the inner ring relative to the inner ring raceway surface, and the large rib protrudes toward the radial outer side. The plurality of tapered rollers are arranged to roll on the inner ring raceway surface. The retainer includes a small diameter annular body, a large diameter annular body, and a plurality of retainer rods. The small diameter annular body is arranged on the one axial side of the retainer, and the large diameter annular body is arranged on the other axial side. The plurality of retainer rods are configured to connect the small diameter annular body and the large diameter annular body. The cage is configured to hold the plurality of tapered rollers in corresponding pockets, each pocket being a space defined between the plurality of cage rods adjacent to each other in the circumferential direction of the cage between the large-diameter annular body and the small-diameter annular body. The cage includes a stopper portion, which is provided to protrude in the circumferential direction of the cage at an axial middle portion of the cage rod, and is configured to prevent each of the plurality of tapered rollers from falling out toward the radially outer side by bringing an axial middle portion on the outer circumferential surface of the tapered roller held in the pocket into contact with the stopper portion. The axial middle portion on the outer circumferential surface of the tapered roller is a portion provided on one axial side and radially outer side of the tapered roller relative to the center of gravity of the tapered roller. The outer ring is provided on the radially outer side relative to the inner ring of the inner ring unit.

[0013] In the tapered roller bearing according to the second form of the present invention, the stop portion can have a triangular prism shape, in which the axial width gradually decreases as the stop portion protrudes from the retaining frame rod in the circumferential direction of the retaining frame, and the first surface that constitutes the triangular prism shape and is arranged on the one axial side relative to the protruding edge of the stop portion can be a contact surface, which forms contact with the axial middle portion on the outer circumferential surface of the tapered roller.

[0014] In the tapered roller bearing according to the second aspect of the present invention, a rounded portion may be provided on a radially inner edge of the contact surface.

[0015] The tapered roller bearing according to the second aspect of the present invention exhibits the same operations and effects as those of the inner ring unit described above.

[0016] According to the inner ring unit of the first aspect and the tapered roller bearing of the second aspect of the present invention, it is possible to reduce strain caused by deformation of the cage during assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0018] Figure 1 is a cross-sectional view showing a tapered roller bearing according to one embodiment of the present invention;

[0019] Figure 2 is an explanatory diagram showing a portion of the retainer viewed from the radial inner side;

[0020] Figure 3 yes Figure 2 An enlarged cross-sectional view of the main parts;

[0021] Figure 4 is Figure 3 A diagram viewed in the direction of arrow A;

[0022] Figure 5 It is along Figure 3 The VV line in the Figure 3 A cross-sectional view observed in the direction of the arrow;

[0023] Fig. 6A is an explanatory diagram showing an assembly process of a tapered roller bearing;

[0024] Figure 6B is an explanatory diagram showing an assembly process of a tapered roller bearing;

[0025] Fig. 7A is an explanatory diagram showing an assembly process of a tapered roller bearing;

[0026] Figure 7B is an explanatory diagram showing an assembly process of a tapered roller bearing;

[0027] Figure 8 is a cross-sectional view showing a tapered roller located on the vertical lower side of the cage; and

[0028] Fig. 9 is a longitudinal sectional view showing a tapered roller bearing of the related art. DETAILED DESCRIPTION

[0029] The structure of tapered roller bearings

[0030] Figure 1: is a cross-sectional view showing a tapered roller bearing according to one embodiment of the present invention. The tapered roller bearing 1 includes an inner ring 3, an outer ring 2, a plurality of tapered rollers 4, and a retainer 10 having an annular shape. The outer ring 2 is disposed on the radially outer side of the inner ring 3. The tapered rollers 4 are interposed between the inner ring 3 and the outer ring 2. The retainer 10 retains the tapered rollers 4. The tapered roller bearing 1 is lubricated with lubricating oil (oil).

[0031] The inner ring 3 is an annular member made of bearing steel, steel for mechanical structural purposes, etc. The inner ring 3 includes a tapered inner ring raceway surface 3a on its outer periphery, and the plurality of tapered rollers 4 roll on the tapered inner ring raceway surface 3a. The inner ring 3 also includes small ribs 5 and large ribs 6. The small ribs 5 are provided on one axial side ( Figure 1 The large rib 6 is arranged on the other axial side ( Figure 1 on the right side in the figure) and protrudes radially outward.

[0032] Each tapered roller 4 is made of, for example, bearing steel. The tapered roller 4 rolls on the outer ring raceway surface 2a and the inner ring raceway surface 3a provided on the inner periphery of the outer ring 2. Each tapered roller 4 includes a small end surface 4a on the one axial side and a large end surface 4b on the other axial side. The small end surface has a small diameter, while the large end surface 4b has a large diameter. The large end surface 4b is in sliding contact with the rib surface 7 of the large rib 6 of the inner ring 3.

[0033] Figure 2 1 is an explanatory diagram showing a portion of the retainer 10 viewed from the radial inner side. Figure 1 and Figure 2 In the embodiment, the retainer 10 includes a small diameter annular body 11 on one axial side, a large diameter annular body 12 on the other axial side, and a plurality of retainer rods 13 arranged at intervals in the circumferential direction. The small diameter annular body 11 and the large diameter annular body 12 have an annular shape and are arranged at predetermined intervals in the axial direction. The retainer rods 13 connect the small diameter annular body 11 and the large diameter annular body 12.

[0034] A space is defined between the small diameter annular body 11 and the large diameter annular body 12 and between any two retainer rods 13 adjacent to each other in the circumferential direction. The space serves as a pocket 14 for retaining (or accommodating) a corresponding one of the tapered rollers 4. The retainer 10 is disposed in the annular space defined between the inner ring 3 and the outer ring 2. In the retainer 10, one tapered roller 4 is accommodated in each pocket 14, and the plurality of tapered rollers 4 are disposed and retained at equal intervals in the circumferential direction. The axial length of the pocket 14 is set to a length that ensures a gap that allows the tapered roller 4 to swing when the tapered roller bearing 1 to be described below is assembled (refer to Fig. 7A and Figure 8 ).

[0035] The retainer 10 can be in sliding contact with the inner peripheral surface (outer ring raceway surface 2a) of the outer ring 2, and the rotation of the retainer 10 is guided by the outer ring 2. In other words, the tapered roller bearing 1 of the present embodiment is an outer ring guide type bearing in which the retainer 10 is guided by the outer ring 2. The retainer 10 is made of a synthetic resin and can be molded by injection molding. The retainer 10 of the present embodiment is made of polyphenylene sulfide resin (PPS), so that the retainer 10 has lubricating oil resistance (has oil resistance). Therefore, the retainer 10 has sufficient hardness and is relatively unlikely to be elastically deformed, but is easy to break.

[0036] Figure 3 yes Figure 2 An enlarged cross-sectional view of the main parts. Figure 4 is Figure 3 A view in the direction of arrow A. Figure 3 and Figure 4 In the embodiment, the retainer 10 has a stopper 20 which is provided in the axial middle portion on the side surface 13a of each retainer rod 13 and protrudes in the circumferential direction. The stopper 20 of the embodiment is formed integrally with the side surface 13a of the retainer rod 13. The stopper 20 comes into contact with the axial middle portion of the outer peripheral surface of the tapered roller 4 accommodated in the pocket 14 (hereinafter referred to as the axial middle portion of the tapered roller 4), so that the tapered roller 4 is prevented from falling out toward the radial outside (falling out when the bearing is assembled).

[0037] The stopper 20 has a triangular prism shape, wherein the axial width gradually decreases as the stopper 20 protrudes from the side surface 13a of the retainer rod 13 in the circumferential direction. The first surface constitutes a triangular prism shape and is arranged on one axial side relative to the protruding edge 21 of the stopper 20. The first surface is a contact surface 22 that makes contact with the axial middle portion of the tapered roller 4. The contact surface 22 has a trapezoidal shape, wherein the radial width gradually increases from the protruding edge 21 toward the one axial side. The contact surface 22 is arranged at a position on the one axial side and the radial outer side relative to the center of gravity G of the tapered roller 4 accommodated in the pocket 14. That is, the axial middle portion of the tapered roller 4 is arranged at the one axial side and the radial outer side relative to the center of gravity G.

[0038] The second surface constitutes a triangular prism shape and is provided on the other axial side relative to the protruding edge 21 of the stopper 20. The second surface is a non-contact surface 23 that does not come into contact with the axial middle portion of the tapered roller 4. The non-contact surface 23 has a rectangular shape whose area is smaller than that of the contact surface 22.

[0039] Figure 5 It is along Figure 3 The VV line in the Figure 3 A cross-sectional view of the arrow direction. Figure 3 and Figure 5 , the protruding edge 21 of the stopper 20 extends linearly in the radial direction. The inner end surface 24 of the stopper 20 on the radial inner side has a planar shape inclined from the radial inner end of the protruding edge 21 toward the radial inner side and toward the side surface 13a of the retainer rod 13. The inclination angle θ of the protruding edge 21 relative to the inner end surface 24 is set so that the stress generated when the axial middle portion of the tapered roller 4 comes into contact with the contact surface 22 is minimized. In the embodiment, the inclination angle θ is set to 20 degrees.

[0040] A rounded portion 25 is provided on the edge on the radially inner side of the contact surface 22 (the contact edge having the inner end surface 24) over the entire length in the axial direction in order to avoid stress concentration when the axial middle portion of the tapered roller 4 comes into contact with the contact surface 22. The radius of curvature of the rounded portion 25 is set so as to minimize the stress generated when the axial middle portion of the tapered roller 4 comes into contact with the contact surface 22. In the embodiment, the radius of curvature is set to 1 mm.

[0041] exist Figure 3 and Figure 4 In the embodiment, the cage 10 further includes a roller stopper 15 which is provided on the radially outer side of the end portion on the other axial side of the side surface 13a of the cage rod 13 and protrudes in the circumferential direction. The roller stopper 15 of the present embodiment is integrally formed on the side surface 13a of the cage rod 13. The roller stopper 15 comes into contact with the large diameter portion 48 on the outer peripheral surface of the tapered roller 4 accommodated in the pocket 14, thereby preventing the tapered roller 4 from falling out toward the radially outer side (falling out when the bearing is assembled).

[0042] The roller stopper 15 is provided at a position where the roller stopper 15 does not come into contact with the tapered roller 4 even when the tapered roller 4 swings in the pocket 14 when the bearing is assembled. Note that the cage 10 can sufficiently prevent the tapered roller 4 from falling out toward the radially outer side only by the stopper 20. Therefore, the cage 10 does not need to include the roller stopper 15.

[0043] Tapered roller bearing assembly process

[0044] Fig. 6A , Figure 6B and Fig. 7A , Figure 7B 1 is an explanatory diagram showing the assembly process of the tapered roller bearing 1. Fig. 6AWhen assembling the tapered roller bearing 1, firstly, each tapered roller 4 is placed into the corresponding pocket 14 from the inner circumference of the cage 10 to assemble the cage 10 and the tapered roller 4, and then the inner ring 3 is assembled to the unit of the cage 10 and the tapered roller 4 ( Figure 7B During this assembly process, the tapered roller 4 accommodated in the pocket 14 must be prevented from falling out radially outward. Therefore, the cage 10 of this embodiment includes the stopper 20 as described above (refer to Figure 3 ).

[0045] To assemble the tapered roller bearing 1, as Fig. 6A As shown in , each tapered roller 4 is accommodated in the corresponding pocket 14 of the cage 10 as described above. Next, the inner ring 3 is brought close to the unit of the cage 10 and the tapered roller 4 from the side of the small rib 5 in the axial direction to assemble the inner ring 3 and the unit. In this process, as shown in Figure 6B As shown in , when the small diameter portion 49 of the tapered roller 4 is displaced toward the radial outside and passes over the small rib 5 of the inner ring 3, the axial middle portion of the tapered roller 4 comes into contact with the stopper portion 20 of the retainer 10. This prevents the tapered roller 4 from falling off toward the radial outside. Therefore, the retainer 10 needs to be deformed by pressing the inner ring 3 against the retainer 10 in the axial direction so that the small diameter portion 49 of the tapered roller 4 passes over the small rib 5.

[0046] However, in this embodiment, the axial middle portion of the tapered roller 4 is a portion disposed on one axial side and radially outside with respect to the center of gravity G of the tapered roller 4. Fig. 7A As shown in FIG. , the tapered roller 4 is Fig. 7A The large diameter portion 48 of the tapered roller 4 swings in the clockwise direction with the stopper 20 as a fulcrum. In other words, the large diameter portion 48 of the tapered roller 4 swings toward the radial inside, and the small diameter portion 49 also swings toward the radial outside. With this configuration, the amount of radially outward displacement required for the small diameter portion 49 of the tapered roller 4 to pass over the small rib 5 can be reduced. Therefore, even when the force pressing the inner ring 3 in the axial direction is small, the small diameter portion 49 of the tapered roller 4 can easily pass over the small rib 5.

[0047] like Figure 7B As shown in , when the inner ring 3 is assembled to the cage 10 in which the tapered rollers 4 are accommodated, the inner ring 3 cannot move in the axial direction in the direction opposite to the direction in which the inner ring 3 is pressed as described below (hereinafter referred to as the "axial opposite direction"). That is, Figure 7B As shown in FIG. 1 , the tapered roller 4 is held in contact with the inner ring raceway surface 3 a disposed radially inward due to its own weight, wherein the tapered roller 4 is located at the center line C (refer to FIG. 1 ) of the cage 10. Figure 1) is positioned on the vertical upper side of the cage 10 in a state aligned with the horizontal direction. With this structure, since the vertical upper side of the small ribs 5 of the inner ring 3 is clamped by the tapered rollers 4 provided on the vertical upper side, the inner ring 3 cannot move in the axial opposite direction.

[0048] like Figure 8 As shown in FIG. 1 , the tapered roller 4 positioned on the vertical lower side of the cage 10 is displaced toward the radial outer side due to its own weight, and the axial middle portion of the tapered roller 4 comes into contact with the contact surface 22 of the stopper portion 20. This causes the tapered roller 4 to move in a radially outward direction with the stopper portion 20 as a fulcrum. Figure 8 . In other words, the large diameter portion 48 of the tapered roller 4 swings toward the radial outside, and the small diameter portion 49 of the tapered roller 4 also swings toward the radial inside. With this configuration, the tapered roller 4 positioned on the vertical lower side of the cage 10 is retained in the cage 10 with the small diameter portion 49 in contact with the inner ring raceway surface 3a. Therefore, since the vertical lower side of the small rib 5 of the inner ring 3 is caught by the tapered roller 4 provided on the vertical lower side, the inner ring 3 cannot move in the axial opposite direction.

[0049] As described above, the inner ring unit 50 composed of the inner ring 3, the tapered roller 4 and the cage 10 cannot be disassembled. This makes it possible to prevent the inner ring unit 50 from being disassembled. Figure 1 , that is, by bringing the outer ring 2 close to the inner ring unit 50 in the axial direction and assembling the outer ring 2 to the inner ring unit 50 .

[0050] As described above, according to the tapered roller bearing 1 of the embodiment, during the assembly process of the tapered roller bearing 1, the tapered roller 4 is accommodated in each pocket 14 of the cage 10, and the inner ring 3 is brought close to the assembled cage 10 in the axial direction. During this process, when the small diameter portion 49 of the tapered roller 4 is displaced toward the radial outside and passes over the small rib 5 of the inner ring 3, the axial middle portion of the tapered roller 4 comes into contact with the stopper 20 of the cage 10. This prevents the tapered roller 4 from falling off toward the radial outside. Therefore, the cage 10 needs to be deformed by pressing the inner ring 3 against the cage 10 in the axial direction.

[0051] However, the axial middle portion of the tapered roller 4 is a portion that is provided on one axial side and radially outward relative to the center of gravity G of the tapered roller 4. Therefore, with the stopper 20 as a fulcrum, the large diameter portion 48 of the tapered roller 4 swings toward the radial inside, while the small diameter portion 49 of the tapered roller 4 swings toward the radial outside. With this configuration, it is possible to reduce the amount of radially outward displacement required for the small diameter portion 49 of the tapered roller 4 to pass over the small rib 5. Therefore, the small diameter portion 49 of the tapered roller 4 can easily pass over the small rib 5.

[0052] Therefore, it is not necessary to press the inner ring 3 against the cage 10 in the axial direction with a large force, and thus it is possible to reduce strain caused by deformation of the cage 10. Therefore, it is possible to suppress whitening or plastic deformation of the cage 10 and cracks from occurring on the cage 10. In particular, when assembling the roller bearing 1, as the size of the tapered roller bearing 1 increases, the force pressing the inner ring 3 against the cage 10 in the axial direction also increases. Therefore, the present invention is advantageous in the case described herein.

[0053] Furthermore, the axial middle portion of the tapered roller 4 is brought into contact with the contact surface 22 of the stopper 20 in the shape of a triangular prism, which is provided on one axial side relative to the protruding edge 21 of the stopper 20, but the axial middle portion of the tapered roller 4 is not brought into contact with the protruding edge 21. This makes it possible to avoid stress concentration on the stopper 20.

[0054] Furthermore, the axially intermediate portion of the tapered roller 4 is brought into contact with the rounded portion 25 provided at the radially inner edge of the contact surface 22 of the stopper 20. This makes it possible to further avoid stress concentration on the stopper 20.

[0055] The embodiments disclosed above should be considered in all respects as illustrative and not restrictive. That is, the inner ring unit and the tapered roller bearing according to the present invention are not limited to those described in the above embodiments shown in the drawings, and various modifications can be made within the scope of the present invention. For example, the shape of the stopper 20 can be any form other than the illustrated form, and can be modified.

Claims

1. An inner ring unit (50), characterized in that include: An inner ring (3), the inner ring (3) comprising an inner ring raceway surface, a small rib and a large rib, the inner ring raceway surface being on the outer periphery of the inner ring (3), the small rib being arranged on one axial side of the inner ring (3) relative to the inner ring raceway surface, and the small rib protruding toward the radial outer side, and the large rib being arranged on the other axial side of the inner ring (3) relative to the inner ring raceway surface, and the large rib protruding toward the radial outer side; a plurality of tapered rollers (4) arranged to roll on the inner ring raceway surface; and A retainer (10), the retainer (10) having an annular shape, the retainer (10) comprising a small diameter annular body, a large diameter annular body and a plurality of retainer rods, the small diameter annular body being arranged on one axial side of the retainer (10), and the large diameter annular body being arranged on the other axial side of the retainer (10), the plurality of retainer rods being configured to connect the small diameter annular body and the large diameter annular body, the retainer (10) being configured to retain the plurality of tapered rollers (4) in corresponding pockets, each pocket being a plurality of retainer rods adjacent to each other in the circumferential direction of the retainer (10) between the large diameter annular body and the small diameter annular body. The space defined between the retaining rods, the retaining frame (10) comprising a stopper, the stopper being arranged to protrude in the circumferential direction of the retaining frame (10) at the axial middle portion of the retaining frame rod, and the stopper being configured to prevent each of the plurality of tapered rollers (4) from falling off toward the radial outer side by bringing the axial middle portion on the outer peripheral surface of the tapered roller (4) retained in the pocket into contact with the stopper, and the axial middle portion on the outer peripheral surface of the tapered roller (4) is a portion arranged on an axial side and radially outer side of the tapered roller (4) relative to the center of gravity of the tapered roller (4), The stop portion has a triangular prism shape, in which the axial width gradually decreases as the stop portion protrudes from the retaining frame rod in the circumferential direction of the retaining frame (10), and the first surface constituting the triangular prism shape and arranged on the one axial side relative to the protruding edge of the stop portion is a contact surface, which forms contact with the axial middle portion on the outer circumferential surface of the tapered roller (4).

2. The inner ring unit (50) according to claim 1, characterized in that A rounded portion is provided on a radially inner edge of the contact surface.

3. A tapered roller bearing, characterized in that include: An inner ring unit (50), the inner ring unit comprising an inner ring (3), a plurality of tapered rollers (4) and a retaining frame (10) having an annular shape, the inner ring (3) comprising an inner ring raceway surface, small ribs and large ribs, the inner ring raceway surface being on the outer periphery of the inner ring (3), the small ribs being arranged on one axial side of the inner ring (3) relative to the inner ring raceway surface, and the small ribs protruding radially outward, the large ribs being arranged on the other axial side of the inner ring (3) relative to the inner ring raceway surface, and the large ribs protruding radially outward, the plurality of tapered rollers (4) being arranged to roll on the inner ring raceway surface, the retaining frame (10) comprising a small diameter annular body, a large diameter annular body and a plurality of retaining frame rods, the small diameter annular body being arranged on one axial side of the retaining frame (10), and the large diameter annular body being arranged on the other axial side, the plurality of retaining frame rods being configured to connect the small diameter annular body and the retaining frame. a large diameter annular body, the retainer (10) being configured to retain the plurality of tapered rollers (4) in corresponding pockets, each pocket being a space defined between the plurality of retainer rods adjacent to each other in the circumferential direction of the retainer (10) between the large diameter annular body and the small diameter annular body, the retainer (10) comprising a stopper, the stopper being arranged to protrude in the circumferential direction of the retainer (10) at an axial middle portion of the retainer rod, and the stopper being configured to prevent each of the plurality of tapered rollers (4) from falling off toward the radial outer side by bringing an axial middle portion on the outer circumferential surface of the tapered roller (4) retained in the pocket into contact with the stopper, the axial middle portion on the outer circumferential surface of the tapered roller (4) being a portion arranged on one axial side and radially outer side of the tapered roller (4) relative to the center of gravity of the tapered roller (4); and an outer ring (2), the outer ring (2) being arranged on the radially outer side relative to the inner ring (3) of the inner ring unit (50), The stop portion has a triangular prism shape, in which the axial width gradually decreases as the stop portion protrudes from the retaining frame rod in the circumferential direction of the retaining frame (10), and the first surface constituting the triangular prism shape and arranged on the one axial side relative to the protruding edge of the stop portion is a contact surface, which forms contact with the axial middle portion on the outer circumferential surface of the tapered roller (4).

4. The tapered roller bearing according to claim 3, characterized in that A rounded portion is provided on a radially inner edge of the contact surface.

Images