JP2014214844A - Conical roller bearing - Google Patents

Abstract

To provide a tapered roller bearing capable of preventing a rolling surface of a tapered roller from being damaged when a combination of a tapered roller and a cage is incorporated into an inner ring without preparing a special jig. A tapered roller bearing (10) includes an outer ring (11), an inner ring (12), a plurality of tapered rollers (13), and a cage (14), and the inner ring (12) has a small flange portion (12b) provided at a small diameter side end portion and a large diameter side end. And the roller surface 13a of the tapered roller 13 is small when the combination of the tapered roller 13 and the retainer 14 is assembled into the inner ring 12 from the small flange 12b side. The surface hardness of the roller contact portion 12d of the small flange portion 12b that contacts the portion 12b and contacts the rolling surface 13a of the tapered roller 13 is set lower than the surface hardness of the rolling surface 13a of the tapered roller 13. [Selection] Figure 1

Description

  The present invention relates to a tapered roller bearing, and more particularly, to a tapered roller bearing that is usually used in an automobile transmission, a differential gear, a general industrial machine, a general machine tool, an automobile, and the like.

  As a conventional tapered roller bearing, 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 an outer ring raceway surface and an inner ring raceway surface are disposed so as to be able to roll. There is known a device including a plurality of tapered rollers and a resin cage that holds the plurality of tapered rollers at equal intervals in the circumferential direction (for example, see Patent Document 1).

  By the way, in the tapered roller bearing described in Patent Document 1, when the inner ring, the tapered roller, and the cage are assembled into the intermediate assembly, the tapered roller and the cage are combined by utilizing the elastic deformation of the resin cage. An assembly method is carried out in which a taper is pushed into the inner ring from the side of the collar and the tapered roller gets over the collar. However, in this assembling method, the rolling surface of the tapered roller may come into contact with the small flange portion, and the rolling surface of the tapered roller may be damaged.

  And in order to prevent the rolling surface of the tapered roller from being damaged, a method for assembling a tapered roller bearing in which a special jig is attached to the inner ring so that the rolling surface of the tapered roller does not contact the small flange portion is known. (For example, refer to Patent Document 2).

JP 2007-057038 A JP 2013-040634 A

  However, in the method of assembling the tapered roller bearing described in Patent Document 2, although it is possible to prevent the rolling surface of the tapered roller from being damaged, it is necessary to prepare a special jig for each of the bearings to be assembled, which increases the manufacturing cost. There was a possibility.

  The present invention has been made in view of the above circumstances, and its purpose is to roll a tapered roller when incorporating a combination of a tapered roller and a cage into an inner ring without preparing a special jig. It is an object of the present invention to provide a tapered roller bearing capable of preventing the surface 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 of the inner ring at substantially equal intervals in the circumferential direction, and the inner ring has a small collar part provided at a small diameter side end part of the inner ring and a large collar part provided at a large diameter side end part of the inner ring When a combination of a tapered roller and a cage is incorporated into the inner ring from the small flange side, the tapered roller rolling surface comes into contact with the small flange portion, and the tapered roller rolling A tapered roller bearing characterized in that the surface hardness of the roller contact portion of the small flange portion that contacts the moving surface is set lower than the surface hardness of the rolling surface of the tapered roller.
(2) In the carburizing and hardening process of the inner ring, the surface hardness of the roller contact portion is set to be lower than the surface hardness of the rolling surface of the tapered roller by applying a carbon-proof treatment to the roller contact portion of the small collar portion. The tapered roller bearing described in (1).
(3) After carburizing and hardening the inner ring, the hardened layer on the surface of the gavel part is removed, the non-hardened part inside the gavel part is exposed, and the non-hardened part is used as a roller contact part. The tapered roller bearing according to (1), wherein the surface hardness of the contact portion is set lower than the surface hardness of the rolling surface of the tapered roller.
(4) A surface hardness of the roller contact portion is obtained by attaching a member having a lower surface hardness than the rolling surface of the tapered roller to the small collar portion of the inner ring and using the lower surface hardness member as the roller contact portion. The tapered roller bearing according to (1), wherein the thickness is set lower than the surface hardness of the rolling surface of the tapered roller.

  According to the present invention, when a combination of a tapered roller and a cage is incorporated into the inner ring from the small collar part side, the rolling surface of the tapered roller contacts the small collar part, and the rolling surface of the tapered roller contacts. To set the surface hardness of the roller contact portion of the small collar lower than the surface hardness of the rolling surface of the tapered roller, when the combination of the tapered roller and the cage is incorporated into the inner ring, the rolling surface of the tapered roller Even if it comes into contact with the small collar portion of the inner ring, the rolling surface of the tapered roller is not damaged. For this reason, it is possible to prevent the rolling surface of the tapered roller from being damaged when a combination of the tapered roller and the cage is incorporated into the inner ring without preparing a special jig.

It is principal part sectional drawing explaining one Embodiment of the tapered roller bearing which concerns on this invention. It is principal part sectional drawing explaining the assembly process of the intermediate assembly shown in FIG. It is principal part sectional drawing of the inner ring | wheel explaining the 1st modification of one Embodiment of the tapered roller bearing which concerns on this invention. It is principal part sectional drawing of the inner ring | wheel explaining the 2nd modification of one Embodiment of the tapered roller bearing which concerns on this invention. It is principal part sectional drawing of the inner ring | wheel explaining the 3rd modification of one Embodiment of the tapered roller bearing which concerns on this invention.

  Hereinafter, an embodiment of a tapered roller bearing according to the present invention will be described in detail based on the drawings.

  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 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 small flange portion 12 b provided at the small diameter side end portion of the inner ring 12 and a large flange portion 12 c provided at the large diameter side end portion of the inner ring 12. The tapered roller 13 has a rolling surface 13a on its outer peripheral surface.

  The cage 14 is formed by injection molding a synthetic resin, and includes a large-diameter-side annular portion 15, a small-diameter-side annular portion 16 arranged coaxially with the large-diameter-side annular portion 15, and a large-diameter side. In order to connect the annular portion 15 and the small-diameter-side annular portion 16, a plurality of column portions 17 arranged at substantially equal intervals in the circumferential direction and column portions 17 adjacent to each other in the circumferential direction are formed. And a pocket 18 for holding the roller in a rollable manner.

  In the tapered roller bearing 10 configured as described above, the intermediate assembly including the inner ring 12, the tapered roller 13, and the cage 14 is a small combination of the tapered roller 13 and the cage 14 as shown in FIG. Assembling is performed by pushing into the inner ring 12 from the flange part 12b side and causing the tapered roller 13 to get over the small flange part 12b while the rolling surface 13a of the tapered roller 13 is in contact with the small flange part 12b of the inner ring 12. And when the tapered roller 13 gets over the small collar part 12b, the rolling surface 13a of the tapered roller 13 contacts the roller contact part 12d which is the outer peripheral surface of the small collar part 12b and the corner | angular part of an axial direction outer end surface.

  By the way, the inner rings and rolling elements of many rolling bearings are made of a material having a very high surface hardness such as bearing steel in order to ensure the life. In particular, carburized steel and some bearing steels realize materials with high surface hardness and toughness by carburizing and induction hardening.

  And in this embodiment, in the carburizing hardening process process of the inner ring | wheel 12, a roller contact part 12d of the small collar part 12b is subjected to a carbon-proofing process. For this reason, carburization hardening processing is performed on the portions other than the roller contact portion 12d of the inner ring 12, and the carburization hardening processing is not performed on the roller contact portion 12d that has been subjected to the carburization prevention treatment. A hardened layer 12e is formed. Thereby, the surface hardness of the roller contact portion 12 d is set lower than the surface hardness of the rolling surface 13 a of the tapered roller 13. In addition, as a carbon-proof process, application | coating of a carbon-proof agent, a copper plating process, etc. can be mentioned, for example.

  Moreover, as a specific example of the surface hardness of the roller contact portion 12d of the inner ring 12 and the surface hardness of the rolling surface 13a of the tapered roller 13, for example, the material of the inner ring 12 and the tapered roller 13 is a material of a shaft, a housing, or a bearing. In the case of chrome molybdenum steel SCM420 which is often used, the surface of the tapered roller 13 has a surface hardness of HV697 to 800 by carburizing and quenching. The surface of the roller contact portion 12d of the inner ring 12 is equivalent to the surface hardness of the tapered roller 13 when carburizing and quenching. However, when carburizing and quenching is not performed, depending on conditions, about HV302 to 484. It becomes the surface hardness. Therefore, the surface hardness of the roller contact portion 12d can be set to HV213 to 498 lower than the surface hardness of the rolling surface 13a of the tapered roller 13.

  Note that the small flange portion 12b of the inner ring 12 normally prevents the tapered roller 13 from falling off, and the roller contact portion 12d of the small flange portion 12b is a portion that receives the contact and load of the tapered roller 13 during bearing rotation. is not. For this reason, even if the roller contact portion 12d is damaged by reducing the surface hardness of the roller contact portion 12d, there is no problem in the bearing function. Therefore, as long as the material of the inner ring 12 is steel, the lower limit of the surface hardness of the roller contact portion 12d is not particularly limited.

  As described above, according to the tapered roller bearing 10 of the present embodiment, the surface hardness of the roller contact portion 12d of the small flange portion 12b with which the rolling surface 13a of the tapered roller 13 contacts is set to roll the tapered roller 13. Even if the rolling surface 13a of the tapered roller 13 comes into contact with the small flange portion 12b when the combination of the tapered roller 13 and the retainer 14 is assembled into the inner ring 12 in order to set the surface hardness lower than the surface hardness of the surface 13a, the tapered shape is obtained. The rolling surface 13a of the roller 13 is not damaged. For this reason, it is possible to prevent the rolling surface 13a of the tapered roller 13 from being damaged when a combination of the tapered roller 13 and the cage 14 is incorporated into the inner ring 12 without preparing a special jig.

  As a first modification of the present embodiment, as shown in FIG. 3, after carburizing and hardening of the inner ring 12, the hardened layer 12 f on the surface of the gavel portion 12 b is ground (see the grinding line A in FIG. 3). The non-hardened part inside the small collar part 12b is exposed and the non-hardened part may be used as the roller contact part 12d. Therefore, the surface hardness of the roller contact portion 12 d is set lower than the surface hardness of the rolling surface 13 a of the tapered roller 13. Moreover, since the depth of the hardened layer 12f is usually about 1 to 3 mm, the grinding amount is also equivalent. Further, when grinding, it is preferable to perform an R chamfering process on the axially outer end portion of the small flange portion 12b. In this case, stress concentration when the rolling surface 13a of the tapered roller 13 contacts is avoided, Scratches and peeling due to excessive surface pressure can be prevented. The removal of the hardened layer 12f described above is not limited to grinding but may be cutting.

  Further, as a second modification of the present embodiment, as shown in FIG. 4, a member having a lower surface hardness than the rolling surface 13 a of the tapered roller 13, such as aluminum, is provided on the small collar portion 12 b of the inner ring 12. The soft metal member 20 may be attached by adhesion, and the soft metal member 20 may be used as the roller contact portion 12d. Therefore, the surface hardness of the roller contact portion 12 d is set lower than the surface hardness of the rolling surface 13 a of the tapered roller 13.

  Further, as a third modification of the present embodiment, as shown in FIG. 5, a member having a surface hardness lower than the rolling surface 13 a of the tapered roller 13, for example, a substantially cross-sectional shape, is provided on the small flange portion 12 b of the inner ring 12. The resin member 30 having a U-shape may be attached by fitting, and the resin member 30 may be used as the roller contact portion 12d. Therefore, the surface hardness of the roller contact portion 12 d is set lower than the surface hardness of the rolling surface 13 a of the tapered roller 13. In this modification, a circumferential groove 12g for fitting the resin member 30 is formed on the end surface on the small diameter side of the inner ring 12.

  The second and third modifications described above are metals having a relatively high carbon content before the heat treatment of the bearing steel SUJ2, etc., and do not need to be subjected to carburizing and hardening treatment. It is suitable when it is difficult. Moreover, since the soft metal member 20 and the resin member 30 described above are not necessary as bearing elements, they may be disassembled and detached after assembly.

In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, the roller contact portion may be formed by performing coating, lining, or metal plating with a resin material or the like on the small collar portion of the inner ring. Although they cannot be expected to have great wear resistance and adhesion, they can be prevented from being damaged by the separation of the rolling surfaces when assembled. In this case, since the peeled material may remain as foreign matter in the bearing, it is desirable to clean it after incorporation.

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 Small flange part 12c Large collar part 12d Roller contact part 13 Tapered roller 13a Rolling surface 14 Cage 20 Soft metal member 30 Resin member

Claims (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 inner ring is a tapered roller bearing having a small flange provided at a small diameter side end of the inner ring, and a large flange provided at a large diameter side end of the inner ring,
When assembling the combination of the tapered roller and the cage into the inner ring from the side of the small collar part, the rolling surface of the tapered roller contacts the small collar part,
A tapered roller bearing characterized in that a surface hardness of a roller contact portion of the small collar portion that contacts a rolling surface of the tapered roller is set lower than a surface hardness of the rolling surface of the tapered roller.   In the carburizing and hardening process of the inner ring, by subjecting the roller contact part of the small collar part to a carburization prevention process, the surface hardness of the roller contact part is lower than the surface hardness of the rolling surface of the tapered roller. The tapered roller bearing according to claim 1, wherein the tapered roller bearing is set.   After the carburizing and hardening treatment of the inner ring, the hardened layer on the surface of the gavel portion is removed, the uncured portion inside the gavel portion is exposed, and the uncured portion is used as the roller contact portion. 2. The tapered roller bearing according to claim 1, wherein a surface hardness of the roller contact portion is set lower than a surface hardness of a rolling surface of the tapered roller.   A member having a lower surface hardness than the rolling surface of the tapered roller is attached to the small collar portion of the inner ring, and the member having a lower surface hardness is used as the roller contact portion. 2. The tapered roller bearing according to claim 1, wherein the surface hardness is set lower than the surface hardness of the rolling surface of the tapered roller.

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