JP2013040634A - Assembling method of conical rolling bearing and conical rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an assembling method of a conical rolling bearing which can prevent a rolling face of the conical roller from being damaged by avoiding the contact of a small flange of an inner ring with the rolling face of the conical roller when assembling the inner ring to a resin-made retainer in a state that the conical roller is temporarily inserted into the retainer, and the conical rolling bearing.SOLUTION: At the assembling, an annular jig 20 is attached to the axial end face of the small flange 12c of the inner ring 12a, the outside diameter face 20a of the jig 20 is formed into a tapered shape, an angle α1 of the outside diameter face 20a of the jig 20 is set smaller than an angle β at the inside diameter side of the conical roller 14 in a state of being held at a pocket 14d, a small outside diameter D3 of the jig 20 is set smaller than an internally-contacting circular diameter D2 of the conical roller 13, and a large outside diameter D4 of the jig 20 is set larger than an outside diameter D5 of the end face of the small flange 12c.

Description

  The present invention relates to a method for assembling a tapered roller bearing and 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 an inner ring unit of a tapered roller bearing provided with a resin cage will be described with reference to FIG.
In the method of assembling the inner ring unit using this resin cage, the resin resin is preliminarily 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 portion 62c facing downward, the tapered diameter of the small collar portion 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 to be larger than the inscribed circle diameter D2 of 63 and set an appropriate tightening allowance. The “tightening allowance” is a difference between the 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 that, for example, resin materials such as materials PA66, PA46, and PPS have a coefficient of linear expansion larger than that of steel. This is because the amount of expansion of the inscribed circle diameter D2 of the roller 63 increases, and the tightening allowance 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.

  As a technique for improving the assemblability when assembling the inner ring 62, the tapered roller 63, and the resin cage 64, the angle α2 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). By setting the angle α2, when the tapered roller 63 gets over the small collar portion 63c and fits into the inner ring raceway surface 62a during assembly, the posture of the tapered roller 63 changes, and the stress acting on the resin cage 64 is reduced. The

Japanese Patent Laid-Open No. 2007-57038

  However, in the tapered roller bearing described in Patent Document 1, the angle α2 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 α2 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 held in the pocket, and as shown in FIG. 18, the small flange portion 62c comes into contact with the rolling surface 63a of the tapered roller 63, 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. An object of the present invention is to provide a method of assembling a tapered roller bearing and a tapered roller bearing that can prevent the rolling surface of the tapered roller from being damaged by avoiding contact with the moving surface.

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, Is set so that the outer diameter of the small flange portion is larger than the inscribed circle diameter of the tapered roller, the tapered roller is held in the pocket, and the cage pocket A method of assembling a tapered roller bearing in which a tapered roller is temporarily inserted and an inner ring is assembled to a cage from the small collar side of the inner ring, and the axial end surface of the small collar is annular when assembled. The outer diameter surface of the jig is tapered, and the angle of the outer diameter surface of the jig is set smaller than the angle on the inner diameter side of the tapered roller held in the pocket. The small outer diameter is set smaller than the inscribed circle diameter of the tapered roller, and the large outer diameter of the jig is set to be equal to or larger than the outer diameter of the end surface of the small flange portion.
(2) The method for assembling a tapered roller bearing according to (1), wherein the cage is made of a synthetic resin.
(3) The tapered roller bearing according to (1) or (2), wherein B / A is set to 5 or more, where A is the average outer diameter of the tapered rollers and B is the average outer diameter of the cage. Assembly method.
(4) The outer diameter surface of the small collar portion is tapered, and the angle of the outer diameter surface of the small collar portion is set to be smaller than the angle on the inner diameter side of the tapered roller held in the pocket. The axial width is set to be equal to or less than (the outer diameter of the small flange portion−the inscribed circle diameter of the tapered roller) × 0.5 / tan (the angle of the outer diameter surface of the small flange portion) (1 The method for assembling the tapered roller bearing according to any one of (1) to (3).
(5) A tapered roller bearing that is assembled by the method of assembling a tapered roller bearing according to any one of (1) to (4).
(6) An outer ring having an outer ring raceway surface on the inner peripheral surface, an inner ring having an inner ring raceway surface on the 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, Is set so that the outer diameter of the small flange portion is larger than the inscribed circle diameter of the tapered roller, the tapered roller is held in the pocket, and the cage pocket 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, and the average outer diameter of the tapered roller is A and the average outer diameter of the cage is B. As described above, B / A is set to 5 or more, the outer diameter surface of the collar portion is tapered, and the angle of the outer diameter surface of the collar portion is the angle on the inner diameter side of the tapered roller held in the pocket. The axial width of the small flange is set to be larger than (the outer diameter of the small flange−the inscribed circle diameter of the tapered roller) × 0.5 / tan (the angle of the outer diameter surface of the small flange). Tapered roller bearings characterized by being made.

  According to the present invention, at the time of assembly, an annular jig is mounted on the axial end surface of the small collar portion, the outer diameter surface of the jig is tapered, and the angle of the outer diameter surface of the jig is set to the pocket. The small outer diameter of the jig is set smaller than the inscribed circle diameter of the tapered roller, and the large outer diameter of the jig is set smaller than that of the small flange portion. Since the outer diameter is set to be greater than the outer diameter of the end face, when the tapered roller gets over the small collar part of the inner ring, the chamfered part at the small diameter side end part of the tapered roller contacts the outer diameter surface of the small collar part, and the tapered roller rolls. The small hook does not touch the moving surface. 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 assembly method of 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 sectional drawing explaining the case where the axial width of a bearing is enlarged and the axial width of a small collar part is enlarged without changing the axial direction length of a tapered roller. It is sectional drawing explaining the case where the axial direction length of a tapered part is enlarged without shortening the axial direction length of a tapered roller, and changing the axial direction width of a bearing. 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 sectional drawing explaining 2nd Embodiment of the tapered roller bearing which concerns on this invention. It is sectional drawing explaining 3rd Embodiment of the tapered roller bearing which concerns on this invention. It is an expanded sectional view of the periphery of the chamfer part of the tapered roller of FIG. It is sectional drawing explaining the 1st-4th modification of a jig | tool. It is sectional drawing explaining the 5th modification of a jig | tool. It is sectional drawing explaining the 6th and 7th modification of a jig | tool. It is sectional drawing explaining the assembly method of the conventional inner ring unit.

  BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a tapered roller bearing assembly method and tapered roller bearing according to the present invention will be described below in detail with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1 to 11, a tapered roller bearing assembling method and a tapered roller bearing according to a first embodiment of the present invention will be 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. In the present embodiment, the outer diameter surface 12d of the small flange portion 12c is formed in a straight shape.

  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.

  As shown in FIG. 2, the tapered roller 13 is held in the pocket 14 d so that the outer diameter D <b> 1 of the small flange portion 12 c of the inner ring 12 is larger than the inscribed circle diameter D <b> 2 of the tapered roller 13. The outer diameter D1 of the small flange portion 12c refers to the diameter dimension 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 diameter of each tapered roller 13 in the assembled state. Refers to the diameter dimension of a circle drawn with a group of edge points located in the innermost direction. Further, in the present embodiment, since the small flange portion 12c of the inner ring 12 has a straight shape, the end surface outer diameter D5 of the small flange portion 12c is the same as the outer diameter D1 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 present embodiment, a jig 20 is used. The jig 20 is formed in an annular shape, and an annular step portion 20b provided on the end surface in the axial direction of the jig 20 and an axially outer side. And an outer diameter surface 20a having a tapered shape that decreases in diameter as it goes away (as it goes away from the annular stepped portion 20b in the axial direction).

  In this embodiment, the angle of the outer diameter surface 20a of the jig 20 (the angle with respect to the central axis of the bearing 10) α1 is set smaller than the angle β on the inner diameter side of the tapered roller 13 held in the pocket 14d. ing. Further, the small outer diameter D3 of the jig 20 is set smaller than the inscribed circle diameter D2 of the tapered roller 13, and the large outer diameter D4 of the jig 20 is equal to the end surface outer diameter D5 (= D1) of the small flange portion 12c. They are set the same. The large outer diameter D4 of the jig 20 may be set to be equal to or greater than the end surface outer diameter D5 of the small flange portion 12c.

  In the assembly process of the inner ring unit 10A, before the inner ring 12 is assembled to the retainer 14 in which the tapered rollers 13 are temporarily inserted in the pockets 14d, the annular step of the jig 20 is arranged on the axial end surface of the small flange portion 12c of the inner ring 12. The part 20b is fitted and attached. Then, with the jig 20 attached to the inner ring 12, the inner ring 12 is press-fitted along the axial direction from the small collar portion 12 c side of the inner ring 12, and the chamfered portion 13 b of the tapered roller 13 is small in the inner ring 12. Continue to press fit until over the buttocks 12c. 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 on which the jig 20 is mounted, the chamfered portion 13b of the tapered roller 13 contacts the tapered outer diameter surface 20a of the jig 20, as shown in FIG. Overcoming the jig 20 while contacting the straight outer diameter surface 12d of the small flange 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 cage 14 at an inclination angle X, [the angle α1 of the outer diameter surface 20a of the jig 20 <(the angle β−inclination angle X on the inner diameter side of the tapered roller 13)). ], 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 α1 of the diameter surface 20a <(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 method of assembling the tapered roller bearing of the present embodiment, when the inner ring unit 10A is assembled, the annular jig 20 is attached to the axial end surface of the small collar portion 12c of the inner ring 12, The outer diameter surface 20a of the jig 20 is tapered, and the angle α1 of the outer diameter surface 20a of the jig 20 is set smaller than the angle β on the inner diameter side of the tapered roller 14 held in the pocket 14d. The small outer diameter D3 of the tool 20 is set to be smaller than the inscribed circle diameter D2 of the tapered roller 13, and the large outer diameter D4 of the jig 20 is set to be equal to or larger than the end surface outer diameter D5 of the small flange portion 12c of the inner ring 12. Therefore, when the tapered roller 13 gets over the small flange portion 12c of the inner ring 12, 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 the tapered roller 13 rolls. The small flange 12c contacts the moving surface 13a. do not do. Thereby, it can prevent that the rolling surface 13a of the tapered roller 13 is damaged. Therefore, even if the outer diameter surface 12d of the small flange portion 12c has a straight shape, the inner ring unit 10A can be assembled without damaging the rolling surface 13a of the tapered roller 13. Furthermore, in order to prevent the rolling surface 13a of the tapered roller 13 from being damaged, it is not necessary to strictly manage the shape (for example, the inclination angle) and the size of the outer diameter surface 12d of the small flange portion 12c.

  Further, as shown in FIG. 6, it is possible to obtain the same effect as in the above embodiment by making the shape of the small collar portion 12c of the inner ring 12 the same as the jig shape. In other words, the outer diameter surface 12d of the small flange portion 12c is tapered so that it is larger on the inner ring raceway side and smaller on the inner ring end surface side, and the outer diameter D1 on the inner ring raceway side of the smaller collar portion 12c is set to be inscribed by the tapered roller 13. The outer diameter D5 on the inner ring end face side of the small flange portion 12c is smaller than the inscribed circle diameter D2 of the tapered roller 13 and the taper angle α2 of the outer diameter surface 12d of the small flange portion 12c is set to the pocket 14d. By setting the angle smaller than the angle β on the inner diameter side of the tapered roller 13 held in the inner ring unit, damage to the rolling surface 13a of the tapered roller 13 during assembly of the inner ring unit 10A is prevented without using a jig. be able to. However, in order to satisfy the above conditions, the width L in the axial direction of the small flange portion 12c is (the outer diameter D1 of the small flange portion 12c1-the inscribed circle diameter D2 of the tapered roller 13) × 0.5 / tan (small flange). It must be set larger than the angle α2) of the outer diameter surface 12d of the portion 12c. When the setting of the axial width L of the small flange portion 12c is satisfied, the axial width of the inner ring 12 may be increased, and accordingly, the axial width of the tapered roller bearing 10 may be increased. In order to suppress the increase in the axial width of the tapered roller bearing 10, for example, as shown in FIG. 7, the axial length of the tapered roller 13 is shortened by an increase in the axial width L of the small flange portion 12c. However, in that case, the rated load of the tapered roller bearing 10 may be reduced. Therefore, it is preferable to use a jig if you do not want to increase the size or decrease the rated load.

  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. 8 and 10, in the two tapered roller bearings 10 having the same inner diameter of the outer ring raceway surface 11 a, 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, if the cage 14 moves closer to the outer ring raceway surface 11a side, there is a possibility that the bearing performance is deteriorated. Therefore, as shown in FIGS. 9 and 11, the outer diameter D7 of the cage 14 is equal to 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. 9), the cage is compared with the case where the outer diameter D8 of the tapered roller 13 is larger (see FIG. 11). 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 has intensively studied the mechanism of scratching the rolling surface 13a of the tapered roller 13, when the B / A is 5 or more, the inner ring unit 10A is tightened so as not to be disassembled. It was found that the rolling surface 13a of the tapered roller 13 would be damaged. Further, as a result of an assembly test for assembling the inner ring unit 10A without a tool, it was found that when the B / A is 5 or more, the rolling surface 13a of the tapered roller 13 is always damaged.

(Second Embodiment)
Next, a tapered roller bearing assembling method and a tapered roller bearing according to a second embodiment of 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.

  As shown in FIG. 12, the jig 30 of the present embodiment is formed in an annular shape, provided on the axial end surface of the jig 30, and a circumferential groove 30 b into which the small collar portion 12 c of the inner ring 12 is fitted, The circumferential groove 30b side has a straight shape, and has an outer diameter surface 30a having a tapered shape that decreases in diameter from the middle toward the outside in the axial direction. In the present embodiment, the large outer diameter D4 of the jig 20 is set to be equal to or larger than the end surface outer diameter D5 of the small flange portion 12c of the inner ring 12. Therefore, in the present embodiment, the small collar portion 12c of the inner ring 12 is covered with the jig 30, and is not exposed to the outside during assembly. In FIG. 12, the outer diameter surface 12d of the small flange portion 12c has a straight shape, but a similar jig can be used even if it has a tapered shape, and the same effect can be obtained.

  As described above, according to the method of assembling the tapered roller bearing of the present embodiment, the small collar portion 12c of the inner ring 12 is covered with the jig 30 and is not exposed to the outside during assembly. At this time, the chamfered portion 13b at the end on the small diameter side of the tapered roller 13 contacts the outer peripheral surface of the jig 30, 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.

  By the way, in the said 1st Embodiment, in order to suppress abrasion of the chamfering part 13b of the tapered roller 13 at the time of assembling the inner ring unit 10A, the hardness of the jig 20 and the small flange part 12c is made lower than the chamfering part 13b. Thus, it is more preferable to wear the jig 20 and the small flange portion 12c instead of the tapered roller 13. For example, wear of the chamfered portion 13b can be suppressed by making the material of the jig 20 softer than the tapered roller 13 such as resin, rubber, copper, or brass. As another countermeasure against wear, it is also effective to reduce the frictional resistance by reducing the surface roughness of the jig 20 and the small flange portion 12c and applying a lubricant such as oil.

However, when the small collar portion 12c of the inner ring 12 is covered with the jig 30 as in the present embodiment, the above-mentioned anti-wear measures may be performed only on the jig 30 that can be replaced as appropriate, so the number of work steps is reduced. The manufacturing cost of the tapered roller bearing 10 can be reduced.
About another structure and an effect, it is the same as that of the said 1st Embodiment.

(Third embodiment)
Next, a tapered roller bearing assembling method and a tapered roller bearing according to a third embodiment of the present invention will be described with reference to FIGS. 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. 13, the outer diameter surface 12d of the small collar portion 12c of the inner ring 12 is formed in a tapered shape that decreases in diameter toward the outer side in the axial direction, and the outer diameter surface of the small collar portion 12c. The angle α2 of 12d is set smaller than the angle β on the inner diameter side of the tapered roller 13 held in the pocket 14d. In this embodiment, the axial width L of the small flange portion 12c is (the outer diameter D1 of the small flange portion 12c-the inscribed circle diameter D2 of the tapered roller 13) × 0.5 / tan (of the small flange portion 12c). The angle α2) or less of the outer diameter surface 12d is set. In the present embodiment, the large outer diameter D4 of the jig 20 is set to be equal to or larger than the end surface outer diameter D5 of the small flange portion 12c of the inner ring 12.

In this embodiment, in the process of press-fitting the inner ring 12 to which the jig 20 is mounted, the chamfered portion 13b of the tapered roller 13 is cured while being in contact with the tapered outer diameter surface 20a of the jig 20. After getting over the tool 20, as shown in FIG. 14, it comes into contact with the tapered outer diameter surface 12d of the small flange portion 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.
About another structure and an effect, it is the same as that of the said 1st Embodiment.

  In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, as shown in FIG. 15A, the jig 20 does not need to be provided with the annular stepped portion 20b (first modified example). Moreover, as shown in FIG.15 (b), the cyclic | annular step part 20b and the lightening part do not need to be provided (2nd modification). Further, as shown in FIG. 15C, the annular step portion 20b is not provided, and the straight portion 20c may be provided at the large-diameter end of the tapered outer diameter surface 20a (third). Modification). Further, as shown in FIG. 15D, the annular step portion 20b is not provided, and the straight portion 20c may be provided at the small-diameter side end portion of the tapered outer diameter surface 20a (fourth modification). Example). In addition, each said modification is applicable also to the jig | tool 30 of 2nd Embodiment.

  Further, in order to prevent the end portion of the small diameter side of the jig from accidentally contacting the rolling surface of the tapered roller and damaging the rolling surface of the tapered roller, as shown in FIG. You may make it attach the annular member 21A which consists of soft materials, such as resin, to the outer edge part of an edge part (5th modification). In addition, as shown in FIG. 17A, an annular member 21B made of a soft material such as resin may be attached to the end surface of the small diameter side end portion of the jig 20 (sixth modification). In addition, as shown in FIG. 17B, a disc member 21C made of a soft material such as resin may be attached to the end surface of the small diameter side end portion of the jig 20 (seventh modification). In addition, each said modification is applicable also to the jig | tool 30 of 2nd 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, the tapered roller bearing (10) shown in FIG. 1 was manufactured with the specifications shown in Table 1, and the jig (20) shown in FIG. 2 was manufactured with the specifications shown in Table 2. Then, it was confirmed whether or not the rolling surface (13a) of the tapered roller (13) was damaged depending on whether or not the jig (20) was used. The test was conducted in a laboratory at a temperature of 20 ° C. and a humidity of 60%.

  When the inner ring unit (10A) was assembled without using the jig (20), the rolling surface (13a) of the tapered roller (13) was damaged. On the other hand, when the inner ring unit (10A) was assembled using the jig (20), 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 in any case.

  Next, the outer diameter D1 of the small flange portion (12c) is reduced to 311.4 mm, that is, the tightening margin with respect to the inscribed circle diameter D2 (= 311.2 mm) of the tapered roller (13) is set to 0.2 mm. An assembly test of the unit (10A) was performed. In this case, the rolling surface (13a) of the tapered roller (13) was not damaged whether or not the jig (20) was used. However, when the inner ring unit (10A) was assembled with the small shaft part (12c) side down with respect to the vertically standing shaft, the inner ring unit (10A) was disassembled in any case.

  Therefore, by mounting the jig (20) satisfying the conditions in Table 2 on the small collar part (12c) of the inner ring (12), the small collar part (12c) is made to contact the rolling surface (13a) of the tapered roller (13). It was found that the inner ring unit (10A) can be assembled without being in contact with the roller), and the rolling surface (13a) of the tapered roller (13) can be prevented from being damaged.

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 13b Chamfered part 14 Cage 14a Large diameter side circle Ring portion 14b Small-diameter side annular portion 14c Column portion 14d Pocket 20 Jig 20a Outer diameter surface D1 Outer diameter of small flange D2 Inscribed circle diameter of tapered roller D3 Small outer diameter of jig D4 Large outer diameter of jig D5 End face outer diameter of small flange α1 Angle of outer diameter surface of jig α2 Angle of outer diameter surface of small flange section β Inner side angle of tapered roller A Average outer diameter of tapered roller B Average outer diameter of cage L Small Axial width of buttocks

Claims (6)

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 of the small flange portion is set to be larger than the inscribed circle diameter of the tapered roller, the tapered roller is held in the pocket,
An assembly method of a tapered roller bearing in which the inner ring is assembled to the retainer from the small collar side of the inner ring in a state where the tapered roller is temporarily inserted in the pocket of the retainer,
At the time of the assembly, an annular jig is mounted on the axial end surface of the gavel portion,
The outer diameter surface of the jig is tapered,
The angle of the outer diameter surface of the jig is set to be smaller than the angle on the inner diameter side of the tapered roller held in the pocket,
The small outer diameter of the jig is set smaller than the inscribed circle diameter of the tapered roller,
A tapered roller bearing assembly method, wherein a large outer diameter of the jig is set to be equal to or larger than an outer diameter of an end surface of the small flange portion.   The method of assembling a tapered roller bearing according to claim 1, wherein the cage is made of a synthetic resin.   3. The method of assembling a tapered roller bearing according to claim 1, wherein B / A is set to 5 or more, where A is the average outer diameter of the tapered rollers, and B is the average outer diameter of the cage. . The outer diameter surface of the small collar portion is tapered,
The 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 in a state of being held in the pocket,
The axial width of the small flange portion is set to be equal to or less than (outer diameter of the small flange portion−inscribed circle diameter of the tapered roller) × 0.5 / tan (angle of the outer diameter surface of the small flange portion). The method for assembling a tapered roller bearing according to any one of claims 1 to 3.   A tapered roller bearing assembled by the method of assembling a tapered roller bearing according to any one of claims 1 to 4. 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 of the small flange portion is set to be larger than the inscribed circle diameter of the tapered roller, the tapered roller is held in the pocket,
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 average outer diameter of the tapered rollers is A, the average outer diameter of the cage is B, and B / A is set to 5 or more,
The outer diameter surface of the small collar portion is tapered,
The 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 in a state of being held in the pocket,
The axial width of the small flange portion is set to be larger than (the outer diameter of the small flange portion−the inscribed circle diameter of the tapered roller) × 0.5 / tan (the angle of the outer diameter surface of the small flange portion). Tapered roller bearings characterized by that.

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