JP5899759B2 - Tapered roller bearing - Google Patents

Description

  The present invention relates to a tapered roller bearing.

  Tapered roller bearings are compact, can support large radial loads and axial loads, and can be used under various conditions from high speed rotation to low speed rotation. It is widely used as a general industrial machine such as a machine, a construction machine, and a printing machine, and as a rotation support part for an automobile transmission.

  The tapered roller bearing includes an outer ring having an outer ring raceway surface on an inner peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, and a plurality of tapered rollers provided so as to be able to roll between the outer ring raceway surface and the inner ring raceway surface. And a cage for holding the tapered rollers at substantially equal intervals in the circumferential direction.

  Conventionally, a cage made of steel has been used for a tapered roller bearing. This steel cage is assembled so that the tapered end is held by the small flange portion at the end on the small diameter side of the inner ring and the steel cage by caulking its axial end. In this steel cage assembly method, first, tapered rollers are temporarily inserted into the pockets of the cage, and the inner ring is assembled in this state. Then, the inner ring, the cage, and the tapered roller are handled as one body (hereinafter also referred to as “inner ring unit”), and a cage caulking jig is pushed into the inner ring unit. In this inner ring unit, the cage caulking jig is caulked until an arbitrary pocket clearance is obtained so that the inner ring, the cage and the tapered roller are not separated. In the so-called steel cage, a caulking method is adopted, and the amount of caulking of the steel cage is adjusted by the amount of pushing of the cage caulking jig.

  However, the steel cage is manufactured by plastically deforming a metal flat plate several times, and is also plastically deformed during caulking, which may reduce the dimensional accuracy. In the assembly process, it is necessary to handle the inner ring, the cage, and the inner ring unit of the tapered roller so as not to be separated. For this reason, the number of processing steps is increased, and the workability is poor due to the weight of the cage. Further, since the material is a metal, the material cost is high and the economic efficiency is poor.

  Accordingly, tapered roller bearings equipped with a resin cage have been widely adopted. Tapered roller bearings equipped with this resin cage are used in automobile transmission devices, differential devices, industrial machines and railway vehicles, and are lighter and more economical than metals. In particular, resin cages are often used as cages for rolling bearings for automobiles.

Next, a method for assembling the inner ring unit of the tapered roller bearing provided with the resin cage will be described with reference to FIG.
In the method of assembling the inner ring unit using this resin cage, the resin cage is previously injection-molded so that an arbitrary pocket gap remains in consideration of elastic deformation during assembly. For this reason, unlike the caulking method in which the inner ring unit is easily separated like a general steel cage, in the assembly process of the tapered roller bearing using the resin cage, as shown in FIG. After the tapered rollers 63 are temporarily inserted into pockets (not shown) of the resin cage 64, the inner ring 62 is press-fitted along the axial direction from the small collar portion 62c side of the inner ring 62 in this state. The pocket is temporarily expanded so that the tapered roller 63 is stored in the pocket. That is, the tapered roller 63 is stored in the pocket by the elastic deformation of the resin cage 64. A so-called resin cage 64 employs a press-fitting method.

  Here, the problem of this press-fitting method is that the outer ring is not yet assembled when transporting after assembly of the inner ring unit of the tapered roller bearing, when combined with the outer ring, during transportation, or when assembled on the shaft. It is necessary to handle the inner ring unit 60A, which is the inner ring 62 in a state where the cage 64 and the tapered roller 63 are integrally assembled, so as not to be separated. When attaching the inner ring unit 60A with the small collar part 62c facing downward, the large outer diameter D1 of the small collar part 62c of the inner ring 62 is tapered to prevent the tapered roller 63 and the resin cage 64 from being separated from the inner ring 62. It is necessary to set it larger than the inscribed circle diameter D2 of the roller 63 and set an appropriate tightening allowance. The “tightening allowance” is a difference between the large outer diameter D1 of the small flange portion 62c of the inner ring 62 and the inscribed circle diameter D2 of the tapered roller 63.

  In order to obtain an appropriate tightening allowance, it is necessary to sufficiently consider the dimensional change due to the temperature and humidity of the resin material of the resin cage 64. The reason is, for example, that resin materials such as materials PA66, PA46, and PPS have a larger coefficient of linear expansion than steel. Therefore, when the temperature during use is high, the expansion amount of the large outer diameter D1 of the small flange portion 62c of the inner ring 62 is larger. This is because the amount of expansion of the inscribed circle diameter D2 of the tapered roller 63 increases, and the tightening margin set at room temperature decreases. Moreover, when the humidity at the time of use is high, the resin cage 64 absorbs moisture, and only the resin cage 64 expands, and the tightening margin may be reduced.

  When the inner ring 62, the tapered roller 63, and the resin cage 64 are not tightened to a predetermined size or more, the inner ring unit 60A is attached to the shaft. There is a possibility that the retainer 64 is separated. On the other hand, if the tightening margin is excessive, when the inner ring 62 is press-fitted into the resin cage 64 in which the tapered rollers 63 are temporarily inserted, the small flange portion 62c of the inner ring 62 comes into contact with the rolling surface 63a of the tapered rollers 63. As a result, the rolling surface 63a may be damaged, and the bearing life may be reduced.

  Further, as a result of intensive studies by the inventors of the present application, each dimension of the components of the bearing has tolerances, and the coefficient of expansion of the resin cage 64 with respect to temperature and humidity is larger than that of steel. It has been found that if the tightening allowance is set so that the inner ring unit 60A is not separated when assembled, the rolling surface 63a of the tapered roller 63 is always damaged when the inner ring unit 60A is assembled. Particularly, when the outer diameter of the tapered roller 63 (average diameter of the maximum outer diameter and the minimum outer diameter) is smaller than the outer diameter of the resin cage 64 (average diameter of the maximum outer diameter and the minimum outer diameter) It was found that the degree of increased.

Further, as a technique for improving the assemblability when assembling the inner ring 62, the tapered rollers 63, and the resin cage 64, the angle α of the outer diameter surface 62d of the small flange portion 62c is set larger than the angle of the inner ring raceway surface 62a. Tapered roller bearings are known (for example, see Patent Document 1). Then, by setting the angle alpha, when the tapered rollers 63 at the time of assembly is fitted on the inner ring raceway surface 62a rides over the small rib portion 6 2 c, changes the orientation of the tapered rollers 63, the stress acting on the resin cage 64 Reduced.

JP 2007-57038 A

  However, in the tapered roller bearing described in Patent Document 1, the angle α of the outer diameter surface 62d of the small flange portion 62c is larger than the angle of the inner ring raceway surface 62a, that is, the angle α of the outer diameter surface 62d of the small flange portion 62c. Is set to be larger than the angle β on the inner diameter side of the tapered roller 63 in the state of being held in the pocket, so that the small flange portion 62c comes into contact with the rolling surface 63a of the tapered roller 63, as shown in FIG. The rolling surface 63a was scratched.

  The present invention has been made in view of the above-described circumstances, and the purpose of the present invention is to assemble the inner ring with a small collar portion of the tapered roller when the inner ring is assembled to a resin cage in which the tapered roller is temporarily inserted. It is an object of the present invention to provide a tapered roller bearing which can avoid contact with the moving surface and prevent the rolling surface of the tapered roller from being damaged.

The above object of the present invention can be achieved by the following constitution.
(1) An outer ring having an outer ring raceway surface on an inner peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, a plurality of tapered rollers provided in a rollable manner between the outer ring raceway surface and the inner ring raceway surface, A retainer that holds the tapered rollers in the circumferential direction at substantially equal intervals, and the retainer includes a large-diameter-side annular portion and a small-diameter-side annular portion that is disposed coaxially with the large-diameter-side annular portion. A large-diameter side annular portion and a small-diameter side annular portion are connected in the axial direction, and are formed between a plurality of column portions provided at substantially equal intervals in the circumferential direction and column portions adjacent to each other in the circumferential direction. A pocket for holding the tapered roller in a rollable manner, and the inner ring has a large collar provided at the large-diameter side end of the inner ring, and a small collar provided at the small-diameter side end of the inner ring, the a, outer diameter surface of the small rib portion has a tapered shape, with the tapered roller into the pocket is placed a temporary retainer, the inner ring is the inner ring relative to the cage A tapered roller bearing which is assembled from the flange portion side, the angle of the outer diameter surface of the tapered shape of the small rib portion is set smaller than the angle of the inner diameter side of the tapered rollers held by the pockets, the small rib portion The inner ring is set so that the small outer diameter is set smaller than the inscribed circle diameter of the tapered roller, the large outer diameter of the small collar is set larger than the inner diameter of the cage, and the tapered roller is temporarily inserted in the cage pocket. When the cage is in the process of getting over the small flange, the cage protrudes to the inner diameter side from the inner diameter side rolling surface of the tapered roller at the smaller diameter than the large outer diameter of the small collar. tapered roller bearings, characterized in that there.

According to the present invention, the taper-shaped angle of the outer diameter surface of the small flange portion is set to be smaller than the angle on the inner diameter side of the tapered roller held in the pocket, and the small outer diameter of the small flange portion is the tapered roller. When the inner ring is assembled with the tapered roller temporarily inserted into the cage pocket, the cage outer diameter is set smaller than the inscribed circle diameter of During the process of getting over the small collar part, the cage protrudes to the inner diameter side of the tapered roller inner diameter side rolling surface at the smaller diameter than the large outer diameter of the small collar part. Sometimes when the tapered roller gets over the small collar part of the inner ring, the inner diameter of the cage is expanded by the small collar part, and the chamfered part at the small diameter side end of the tapered roller contacts the outer diameter surface of the small collar part, The small flange does not contact the rolling surface of the tapered roller. Thereby, it is possible to prevent the rolling surface of the tapered roller from being damaged.

It is sectional drawing explaining 1st Embodiment of the tapered roller bearing which concerns on this invention. It is sectional drawing explaining the inner ring | wheel unit shown in FIG. It is an expanded sectional view of the periphery of the chamfered part of the tapered roller of FIG. It is sectional drawing explaining the case where an inner ring | shaft is inclined and attached with respect to a holder | retainer. It is sectional drawing explaining the case where an inner ring | wheel is attached with respect to a holder | retainer in the state in which the one side of the holder | retainer was fully integrated. It is a schematic diagram of a tapered roller bearing in which the outer diameter of the tapered roller is smaller than the outer diameter of the cage. It is an enlarged view of the periphery of the tapered roller of FIG. It is a schematic diagram of a tapered roller bearing in which the outer diameter of the tapered roller is larger than the outer diameter of the cage. It is an enlarged view of the periphery of the tapered roller of FIG. It is a principal part expanded sectional view explaining the modification of the small collar part of the tapered roller bearing which concerns on this invention. It is sectional drawing explaining the inner ring unit of 2nd Embodiment of the tapered roller bearing which concerns on this invention. It is sectional drawing explaining the conventional inner ring | wheel unit. It is sectional drawing explaining the other conventional inner ring | wheel unit.

  Hereinafter, each embodiment of the tapered roller bearing according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1-10, 1st Embodiment of the tapered roller bearing which concerns on this invention is described.

  As shown in FIG. 1, the tapered roller bearing 10 of this embodiment includes an outer ring 11 having an outer ring raceway surface 11a on an inner peripheral surface, an inner ring 12 having an inner ring raceway surface 12a on an outer peripheral surface, an outer ring raceway surface 11a and an inner ring. A plurality of tapered rollers 13 provided so as to be able to roll between the raceway surface 12a and a synthetic resin cage 14 that holds the plurality of tapered rollers 13 at substantially equal intervals in the circumferential direction.

  The inner ring 12 has a large collar part 12 b provided at the large diameter side end part of the inner ring 12 and a small collar part 12 c provided at the small diameter side end part of the inner ring 12. Further, the outer diameter surface 12d of the small flange portion 12c is formed in a tapered shape that decreases in diameter as it goes outward in the axial direction (as it goes away from the inner ring raceway surface 12a in the axial direction).

  The tapered roller 13 has a rolling surface 13a and chamfered portions 13b provided at both edges in the axial direction of the rolling surface 13a.

  The retainer 14 is formed by injection molding of a synthetic resin, and includes a large-diameter side annular portion 14a, a small-diameter-side annular portion 14b arranged coaxially with the large-diameter-side annular portion 14a, and a large-diameter-side annular ring. The portion 14a and the small-diameter-side annular portion 14b are connected in the axial direction, and are formed between a plurality of column portions 14c provided at substantially equal intervals in the circumferential direction and the column portions 14c adjacent to each other in the circumferential direction. A pocket 14d for holding the roller 13 in a rollable manner.

  2 and 3, the tapered roller 13 is held in the pocket 14d so that the large outer diameter D1 of the small flange portion 12c of the inner ring 12 is larger than the inscribed circle diameter D2 of the tapered roller 13. ing. The large outer diameter D1 of the small flange portion 12c indicates the diameter dimension of the large-diameter side edge portion of the outer diameter surface 12d of the small flange portion 12c, and the inscribed circle diameter D2 of the tapered roller 13 is the assembled state. The diameter dimension of the circle drawn by the group of edge points located in the innermost side in the radial direction among the tapered rollers 13 is indicated.

  In the present embodiment, the angle α of the outer diameter surface 12d of the small flange portion 12c is set smaller than the angle β on the inner diameter side of the tapered roller 13 held in the pocket 14d of the cage 14. Further, the small outer diameter D3 of the small flange portion 12c is set smaller than the inscribed circle diameter D2 of the tapered roller 13. The small outer diameter D3 of the small flange portion 12c indicates the diameter dimension of the small diameter side edge portion of the outer diameter surface 12d of the small flange portion 12c.

  In the present embodiment, the average outer diameter of the tapered rollers 13 is A, and the average outer diameter of the cage 14 is B. B / A is set to 5 or more. The average outer diameter A of the tapered roller 13 refers to the average diameter of the maximum outer diameter and the minimum outer diameter of the tapered roller 13, and the average outer diameter of the cage 14 refers to the maximum outer diameter and the minimum outer diameter of the cage 14. Refers to the average diameter.

  Next, an assembly process of the inner ring unit 10A will be described with reference to FIG. The inner ring unit 10 </ b> A is a state in which the outer ring 11 is not yet assembled, and the plurality of tapered rollers 13 and the cage 14 are assembled to the inner ring 12.

  In the assembly process of the inner ring unit 10A, the inner ring 12 is press-fitted along the axial direction from the small flange portion 12c side of the inner ring 12 into the cage 14 in which the tapered rollers 13 are temporarily inserted in the pockets 14d. The press-fitting continues until the chamfered portion 13b of the roller 13 gets over the small flange portion 12c of the inner ring 12. At this time, the tapered roller 13 temporarily spreads the pocket 14d, the tapered roller 13 is accommodated in the pocket 14d, and the inner ring unit 10A is assembled.

  Here, in the process of press-fitting the inner ring 12, the chamfered portion 13b of the tapered roller 13 is small while being in contact with the tapered outer diameter surface 12d of the small flange portion 12c of the inner ring 12, as shown in FIG. Get over the buttocks 12c. For this reason, when the tapered roller 13 tries to get over the small flange portion 12c of the inner ring 12, the rolling surface 13a of the tapered roller 13 does not contact the small flange portion 12c.

  In normal assembly, the inner ring 12 is press-fitted from the large-diameter side annular portion 14a side of the retainer 14 with the center axis of the inner ring 12 aligned with the center axis of the retainer 14. For example, FIG. As shown, when the inner ring 12 is attached to the retainer 14 at an inclination angle X, [the angle α of the outer diameter surface 12d of the small flange portion 12c <(the angle β of the tapered roller 13 on the inner diameter side−the inclination angle X). ]], The inner ring unit 10A can be assembled without damaging the rolling surface 13a of the tapered roller 13.

  Further, as shown in FIG. 5, when assembling in a state where one side of the retainer 14 is completely assembled (when the inner ring 12 is attached to the retainer 14 at an inclination angle Y), If the angle α of the outer diameter surface 12d <(angle β on the inner diameter side of the tapered roller 13 + inclination angle Y)], the inner ring unit 10A can be assembled without damaging the rolling surface 13a of the tapered roller 13.

  As described above, according to the tapered roller bearing 10 of the present embodiment, the tapered roller 13 in a state where the angle α of the outer diameter surface 12d of the small flange portion 12c of the inner ring 12 is held in the pocket 14d of the cage 14. Since the small outer diameter D3 of the small flange portion 12c is set smaller than the inscribed circle diameter D2 of the tapered roller 13, the tapered roller 13 is set to the inner ring 12 when the inner ring unit 10A is assembled. When getting over the small flange portion 12c, the chamfered portion 13b at the small diameter side end portion of the tapered roller 13 comes into contact with the outer diameter surface 12d of the small flange portion 12c and contacts the rolling surface 13a of the tapered roller 13 with the small flange portion 12c. Does not touch. Thereby, it can prevent that the rolling surface 13a of the tapered roller 13 is damaged.

  Here, the usefulness of this embodiment is demonstrated with reference to FIG.12 and FIG.13. The same or equivalent parts as those of the inner ring unit 60A are given the same or equivalent reference numerals in the drawings, and the description thereof is omitted or simplified.

  In the inner ring unit 60A shown in FIG. 12, the angle α of the outer diameter surface 62d of the small flange portion 62c of the inner ring 62 is set to be larger than the angle β on the inner diameter side of the tapered roller 63 held in the pocket of the cage 64. This is different from the present embodiment. For this reason, when the tapered roller 63 gets over the small flange portion 62c, as shown in the contact portion between the small flange portion 62c of the inner ring 62 and the rolling surface 63a of the tapered roller 63 in FIG. It can be seen that the gavel portion 62c contacts the moving surface 63a.

  Further, the inner ring unit 70A shown in FIG. 13 is different from the present embodiment in that the small outer diameter D3 of the small flange portion 62c of the inner ring 62 is set larger than the inscribed circle diameter D2 of the tapered roller 63. For this reason, when the tapered roller 63 gets over the small flange portion 62c, as shown in the contact portion between the small flange portion 62c of the inner ring 62 and the rolling surface 63a of the tapered roller 63 in FIG. It can be seen that the gavel portion 62c contacts the moving surface 63a.

  Next, the technical significance of setting B (average outer diameter of the cage) / A (average outer diameter of the tapered roller) to 5 or more in the present embodiment will be described.

  As shown in FIGS. 6 and 8, in the two tapered roller bearings 10 having the same inner diameter of the outer ring raceway surface 11a, the resin cage 14 has a larger linear expansion coefficient than that of steel. In general, the cage 14 tends to be closer to the outer ring raceway surface 11a side than at room temperature. Here, since the bearing performance may be deteriorated when the cage 14 moves closer to the outer ring raceway surface 11a side, as shown in FIGS. 7 and 9, the outer diameter D7 of the cage 14 is equal to that of the outer ring raceway surface 11a. It is set to a value obtained by subtracting the predetermined value S from the inner diameter D6. That is, the outer diameter D7 of the retainer 14 needs to be equal to or smaller than the outer diameter D8 of the tapered roller 13 (the inner diameter D6-S of the outer ring 11). In order to increase the number of tapered rollers 13 as much as possible, the maximum diameter (inner diameter D6-S of the outer ring 11) is often set. This is because if the number of the tapered rollers 13 is increased, the tapered rollers 13 approach each other, the column portion 14c becomes thin, and the rigidity of the cage 14 decreases, so that the outer diameter D7 of the cage 14 is increased as much as possible. This is because the part 14c is desired to be thick.

  When the outer diameter D8 of the tapered roller 13 is smaller than the outer diameter D7 of the cage 14 (see FIG. 7), the cage is compared with the case where the outer diameter D8 of the tapered roller 13 is larger (see FIG. 9). The opening angle Z of the 14 pockets 14d is reduced, but the movement amount of the pockets 14d in the circumferential direction is set constant, so that the movement amount of the tapered rollers 13 in the radial direction is increased. That is, the tolerance of the inscribed circle diameter D2 of the tapered roller 13 is increased. Therefore, in order to prevent the tapered roller 13 from being separated, it is necessary to secure a tightening margin with the small flange portion 12c even when the inscribed circle diameter D2 of the tapered roller 13 is maximized. For this reason, when the outer diameter D8 of the tapered roller 13 is smaller than the outer diameter D7 of the retainer 14, the maximum fastening allowance is larger than when the outer diameter D8 of the tapered roller 13 is large. That is, when the inner ring unit 10A is assembled, the rolling surface 13a of the tapered roller 13 is easily damaged.

  Further, when the outer diameter D8 of the tapered roller 13 is small, the cage 14 is thinner and less rigid than the case where the outer diameter D8 of the tapered roller 13 is large, so the inner ring unit 10A is assembled to the shaft. At this time, the retainer 14 tends to be elliptical. Therefore, when the assembly is performed in this state, some of the tapered rollers 13 get over the small flange portion 12c of the inner ring 12, and this triggers, and finally all the tapered rollers 13 get over the small flange portion 12c. An avalanche phenomenon occurs, and the tapered roller 13 falls off. In order to prevent this, it is necessary to further increase the tightening allowance. However, when the inner ring unit 10A is assembled, the problem that the rolling surface 13a of the tapered roller 13 is damaged becomes significant.

  As described above, when the inventor of the present application intensively studied the mechanism of scratching the rolling surface 13a of the tapered roller 13, when B / A is 5 or more, the tightening margin is set so that the inner ring unit 10A is not disassembled. It was found that the rolling surface 13a of the tapered roller 13 would be damaged.

  As a modification of the present embodiment, as shown in FIG. 10, a straight portion 12e may be formed at the large-diameter side end of the outer diameter surface 12d of the small flange portion 12c. In this case as well, the same effect as in the above embodiment can be obtained.

(Second Embodiment)
Next, a second embodiment of the tapered roller bearing according to the present invention will be described with reference to FIG. Note that the same or equivalent parts as those in the first embodiment are given the same or equivalent reference numerals in the drawings, and the description thereof is omitted or simplified.

  In the present embodiment, as shown in FIG. 11, an extending portion 15 extending radially inward is formed on the inner peripheral surface of the column portion 14 c of the cage 14, and is smaller than the inner diameter D <b> 4 of the extending portion 15. The large outer diameter D1 of the collar portion 12c is set large. In this case, since the tapered roller 13 is held by the retainer 14 after the inner ring unit 10A is assembled, the large outer diameter D1 of the small flange portion 12c is set smaller than the inscribed circle diameter D2 of the tapered roller 13. May be.

As described above, according to the tapered roller bearing 10 of the present embodiment, the tapered roller 13 in a state where the angle α of the outer diameter surface 12d of the small flange portion 12c of the inner ring 12 is held in the pocket 14d of the cage 14. The small outer diameter D3 of the small flange portion 12c is set smaller than the inscribed circle diameter D2 of the tapered roller 13, and the large outer diameter D1 of the small flange portion is Since it is set larger than the inner diameter D4 of the extension part 15, when the tapered roller 13 gets over the small collar part 12c of the inner ring 12 when the inner ring unit 10A is assembled, the inner diameter D4 of the retainer 14 is pushed by the small collar part 12c. The chamfered portion 13b at the small diameter side end of the tapered roller 13 contacts the outer diameter surface 12d of the small flange portion 12c, and the small flange portion 12c does not contact the rolling surface 13a of the tapered roller 13. Thereby, it can prevent that the rolling surface 13a of the tapered roller 13 is damaged.
About another structure and an effect, it is the same as that of the said 1st Embodiment.

  Next, with reference to Table 1 and Table 2, the Example of the tapered roller bearing which concerns on this invention is demonstrated.

  In this example, three types of bearings of the present invention example, comparative example 1 and comparative example 2 were manufactured by changing the specifications of the small flange portions (12c, 62c) of the inner ring (12, 62). Then, it was confirmed whether or not the rolling surfaces (13a, 63a) of the tapered rollers (13, 63) were damaged when the inner ring units (10A, 60A, 70A) of the respective bearings were assembled. The test was performed in a laboratory at a temperature of 20 ° C. and a humidity of 60%. Table 1 shows common specifications of each bearing, and Table 2 shows individual specifications of each bearing.

  When the inner ring unit (60A) of Comparative Example 1 is assembled, the large-diameter side edge of the outer diameter surface (62d) of the small flange portion (62c) contacts the rolling surface (63a) of the tapered roller (63). As a result, the rolling surface (63a) was scratched. Further, when the inner ring unit (70A) of Comparative Example 2 is assembled, the small-diameter side edge of the outer diameter surface (62d) of the small flange portion (62c) contacts the rolling surface (63a) of the tapered roller (63). As a result, the rolling surface (63a) was scratched.

  On the other hand, when the inner ring unit (10A) of the present invention was assembled, the rolling surface (13a) of the tapered roller (13) was not damaged. In addition, when the inner ring unit (10A) was assembled with the small collar part (12c) side down with respect to the vertical shaft, the inner ring unit (10A) was not disassembled.

  Next, the large outer diameter D1 of the small flange portion (12c) is reduced to 311.4 mm, that is, the tightening margin for the inscribed circle diameter D2 (= 311.2 mm) of the tapered roller (13) is 0.2 mm, An assembly test of the inner ring unit (10A) was performed. Also in this case, the rolling surface (13a) of the tapered roller (13) was not damaged. However, disassembly of the inner ring unit (10A) occurred when the inner ring unit (10A) was incorporated with the small collar part (12c) side down with respect to the vertically standing shaft.

  Therefore, regarding the tapered roller bearing (10), the angle α of the outer diameter surface (12d) of the small flange portion (12c) is set to the tapered roller (13) held in the pocket (14d) of the cage (14). The small flange portion (12c) is conical by setting it smaller than the angle β on the inner diameter side and setting the small outer diameter D3 of the small flange portion (12c) smaller than the inscribed circle diameter D2 of the tapered roller (13). It can be seen that the inner ring unit (10A) can be assembled without contacting the rolling surface (13a) of the roller (13), and the rolling surface (13a) of the tapered roller (13) can be prevented from being damaged. It was.

DESCRIPTION OF SYMBOLS 10 Tapered roller bearing 10A Inner ring unit 11 Outer ring 11a Outer ring raceway surface 12 Inner ring 12a Inner ring raceway surface 12b Large collar part 12c Small collar part 12d Outer diameter surface 13 Tapered roller 13a Rolling surface 14 Cage 14a Large diameter side annular part 14b Small diameter Side ring portion 14c Column portion 14d Pocket D1 Large outer diameter of small flange D2 Inscribed circle diameter of tapered roller D3 Small outer diameter of small flange D4 Inner diameter of cage α Angle of outer diameter surface of small flange β Conical Angle on the inner diameter side of the roller A Average outer diameter of the tapered roller B Average outer diameter of the cage

Claims (1)

An outer ring having an outer ring raceway surface on an inner peripheral surface, an inner ring having an inner ring raceway surface on an outer peripheral surface, a plurality of tapered rollers provided in a rollable manner between the outer ring raceway surface and the inner ring raceway surface; A retainer for holding the tapered rollers in the circumferential direction at substantially equal intervals,
The cage includes a large-diameter side annular portion, a small-diameter-side annular portion arranged coaxially with the large-diameter-side annular portion, and the large-diameter-side annular portion and the small-diameter-side annular portion as axes. A plurality of column portions that are connected in the direction and provided at substantially equal intervals in the circumferential direction, and pockets that are formed between the column portions adjacent to each other in the circumferential direction and hold the tapered rollers in a rollable manner. Have
The inner ring has a large collar portion provided at a large diameter side end portion of the inner ring, and a small collar portion provided at a small diameter side end portion of the inner ring,
The outer diameter surface of the small collar portion has a tapered shape,
A tapered roller bearing in which the inner ring is assembled to the cage from the small collar side of the inner ring with the tapered roller temporarily inserted in the pocket of the cage,
The taper-shaped angle of the outer diameter surface of the small collar portion is set smaller than the angle on the inner diameter side of the tapered roller held in the pocket,
A small outer diameter of the small flange portion is set smaller than an inscribed circle diameter of the tapered roller,
A large outer diameter of the small collar portion is set larger than an inner diameter of the cage ;
When the inner ring is assembled in a state where the tapered rollers are temporarily inserted in the pocket of the cage, in the middle of the cage trying to get over the small collar portion, the larger outer diameter of the small collar portion A tapered roller bearing in which the cage protrudes toward the inner diameter side from the inner diameter side rolling surface of the tapered roller at a small diameter portion .