JP2017150649A - Conical roller bearing and method of manufacturing conical roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conical roller bearing capable of improving seizure resistance while suppressing increase of a manufacturing cost, and a method of manufacturing the conical roller bearing.SOLUTION: An inner ring 12 of a conical roller bearing 10 includes: a small flange part 15 provided at a small-diameter side end part of an inner ring raceway surface 12a; a large flange part 16 provided at a large-diameter side end part of the inner ring raceway surface 12a; and a relief groove 18 provided at a boundary part between the inner ring raceway surface 12a and a large flange surface 16a of the large flange part 16. An axial width W1 of the relief groove 18 is set larger than a radial width W2 of the relief groove 18.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tapered roller bearing and a method for manufacturing a tapered roller bearing.

  In the conventional tapered roller bearing, as shown in FIG. 5, the inner ring raceway surface 112a of the inner ring 112 and the large flange surface 116a that contacts the large diameter side end surface 113b of the tapered roller 113 of the large flange portion 116 are finished by grinding. Therefore, a relief groove 118 is formed at the boundary between the inner ring raceway surface 112a and the large collar surface 116a. The escape groove 118 is formed by cutting a circular arc-shaped cutting tool B into a boundary portion and cutting. The relief groove 118 is usually processed before and after the turning process, but may be performed after the quenching process for measures against heat treatment deformation and surface treatment of the heat treatment layer.

  Further, as conventional tapered roller bearings, there are known ones that improve seizure resistance by limiting numerically the height of the contact point and the height of the escape groove with the large-diameter side end surface of the large flange surface (for example, , See Patent Document 1).

  Further, as a conventional tapered roller bearing, a foamed solid lubricant is disposed in the relief groove (see, for example, Patent Document 2), a lubricant-containing polymer member is disposed in the relief groove (see, for example, Patent Document 3), And what forms the hole which stores lubricating oil in a relief groove (for example, refer to patent documents 4) is known.

Japanese Patent Laid-Open No. 11-190333 JP 2008-298121 A Japanese Patent Laid-Open No. 11-223222 Japanese Patent No. 4399905

  By the way, in the tapered roller bearing described in the above-mentioned Patent Document 1, numerical limits on the height of the contact point and the height of the escape groove with the large-diameter side end surface of the large collar surface are strictly defined. There was a possibility of increase. Further, the tapered roller bearings described in Patent Documents 2 and 3 require a separate member, which may increase the manufacturing cost. Moreover, in the tapered roller bearing described in Patent Document 4, additional processing is performed on the relief groove, which may increase the manufacturing cost.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a tapered roller bearing and a method of manufacturing a tapered roller bearing that can improve seizure resistance while suppressing manufacturing costs. It is in.

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 the inner peripheral surface, an inner ring having an inner ring raceway surface on the outer peripheral surface, and a plurality of tapered rollers arranged to be rollable between the outer ring raceway surface and the inner ring raceway surface; The inner ring includes a small flange provided at the small diameter end of the inner ring raceway surface, a large flange provided at the large diameter end of the inner ring raceway surface, and a large collar surface of the inner ring raceway surface and the large collar portion. A tapered roller bearing having a relief groove provided at a boundary portion between the relief groove and the axial groove, wherein the axial width of the relief groove is set larger than the radial width of the relief groove.
(2) 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, and a plurality of tapered rollers arranged to be rollable between the outer ring raceway surface and the inner ring raceway surface; The inner ring includes a small flange provided at the small diameter end of the inner ring raceway surface, a large flange provided at the large diameter end of the inner ring raceway surface, and a large collar surface of the inner ring raceway surface and the large collar portion. And a clearance groove provided at a boundary portion of the tapered roller bearing, wherein the clearance groove is formed by inserting a cutting tool into the boundary portion, and the cutting tool is connected to the boundary portion or the inner ring raceway surface in the vicinity of the boundary portion. A method for manufacturing a tapered roller bearing, wherein the cutting tool is moved while maintaining the insertion angle of the cutting tool to form a relief groove.

  According to the present invention, since the axial width of the escape groove is set to be larger than the radial width of the escape groove, the lubricant is likely to accumulate in the escape groove as compared with the conventional escape groove. Accordingly, the lubricity around the relief groove is improved, so that the seizure resistance of the tapered roller bearing can be improved and the friction torque can be reduced while suppressing the manufacturing cost.

It is sectional drawing explaining 1st Embodiment of the tapered roller bearing which concerns on this invention. It is an expanded sectional view of the periphery of the large ridge side escape groove shown in FIG. It is an expanded sectional view explaining 2nd Embodiment of the tapered roller bearing which concerns on this invention. It is an expanded sectional view explaining the case where the curvature radius of the front-end | tip circular arc shape of the cutting tool which forms a relief groove is enlarged. It is an expanded sectional view explaining the conventional escape groove.

  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 FIG.1 and FIG.2, 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 disposed so as to be able to roll between the raceway surface 12a and a cage 14 that holds the plurality of tapered rollers 13 at equal intervals in the circumferential direction.

  The inner ring 12 includes a small flange portion 15 provided at a small diameter side end portion of the inner ring raceway surface 12a, a large collar portion 16 provided at a large diameter side end portion of the inner ring raceway surface 12a, an inner ring raceway surface 12a, and a small flange portion 15. A small flange side relief groove 17 provided at a boundary portion between the small collar surface 15a and a large collar side relief groove 18 provided at a boundary portion between the inner ring raceway surface 12a and the large collar surface 16a of the large collar portion 16. Have. The small flange surface 15 a is a surface that contacts the small diameter side end surface 13 a of the tapered roller 13 of the small flange portion 15, and the large flange surface 16 a contacts the large diameter side end surface 13 b of the tapered roller 13 of the large flange portion 16. It is a surface to do.

  The cage 14 is formed by injection molding of a synthetic resin or pressing of an iron plate, and the like. The small diameter side annular portion 14a, the large diameter side annular portion 14b arranged coaxially with the small diameter side annular portion 14a, In order to connect the small-diameter-side annular portion 14a and the large-diameter-side annular portion 14b, a plurality of column portions 14c arranged at substantially equal intervals in the circumferential direction, and the column portions 14c adjacent to each other in the circumferential direction. A pocket portion 14d for holding the tapered roller 13 in a rollable manner is formed therebetween.

  In the present embodiment, as shown in FIG. 2, the axial width W <b> 1 of the large heel-side relief groove 18 is set larger than the radial width W <b> 2 of the large heel-side relief groove 18. As a result, the volume of the large flange side relief groove 18 is larger than that of the conventional relief groove 118 shown in FIG. Accordingly, since the lubricity around the large flange side relief groove 18 is improved, the seizure resistance of the large diameter side end surface 13b and the large flange surface 16a of the tapered roller 13 can be improved and the friction torque can be reduced. Can do. Specifically, the large heel-side relief groove 18 has a cross-sectional shape in which the track-side straight portion 18c is longer than the large ridge-side straight portion 18b with respect to the curved portion 18a.

  Further, the large flange side relief groove 18 is formed by inserting the cutting tool B at a predetermined angle into the boundary portion between the inner ring raceway surface 12a and the large flange surface 16a. The insertion angle θ1 with respect to the axis CL is made smaller than the conventional insertion angle θ2. Specifically, the insertion angle θ1 of the cutting tool B <the large opening angle θ3 ÷ 2 + the inner ring raceway surface angle θ4. The large hook opening angle θ3 is an angle formed by the inner ring raceway surface 12a and the large collar surface 16a, and the inner ring raceway angle θ4 is an angle of the inner ring raceway surface 12a with respect to the bearing center axis CL. Accordingly, the large flange side relief groove 18 can be formed simply by changing the insertion angle of the cutting tool B, and no significant design change or a separate member is required, thereby reducing the manufacturing cost. can do. In the present embodiment, the radial position of the cutting tool B is adjusted so that the radial width W2 of the large flange side relief groove 18 is equal to or less than the radial width of the conventional relief groove 118.

  Further, in the tapered roller bearing 10 configured as described above, the contact position between the inner ring raceway surface 12a and the rolling surface of the tapered roller 13 is far from the groove bottom of the large collar side relief groove 18, so that the large collar side relief groove is provided. It is possible to reduce the stress concentration on 18 and improve the strength of the large collar portion 16.

  As described above, according to the tapered roller bearing 10 of the present embodiment, the axial width W1 of the large collar side relief groove 18 is set larger than the radial width W2 of the large collar side relief groove 18, so that Compared with the relief groove, the lubricant tends to accumulate in the large flange side relief groove 18. Accordingly, since the lubricity around the large flange side relief groove 18 is improved, the seizure resistance of the tapered roller bearing 10 can be improved and the friction torque can be reduced while suppressing the manufacturing cost.

  As a method of increasing the volume of the large flange side relief groove 18, as shown in FIG. 4, it is conceivable to increase the radius of curvature of the tip arc shape of the bite B, but when the radius of curvature is simply increased, Since it is surrounded by the inner ring raceway surface 12a and the concave large flange surface 16a, the degree of freedom of processing is low, and the size of the tool B that can be inserted and the radius of curvature of the arc shape may be limited. Even if the radius of curvature of the arc shape can be increased, the radial width of the large flange side relief groove 18 also increases, so that the contact point between the large diameter side end surface 13b of the tapered roller 13 and the large flange surface 16a is the relief groove. There is a risk of falling inside. Also, if the relief groove is made shallow as a countermeasure, the escape groove volume cannot be increased, and the cutting tool may interfere with the grinding wheel. Further, as shown in FIG. 4, if the cutting amount of the inner ring raceway surface 12a is increased while the radial width of the large flange side relief groove 18 is secured, the inner ring wall thickness of the groove bottom portion becomes thin, and the inner ring There is concern about a decrease in the crack strength of itself. Furthermore, although a method of increasing the insertion depth of the cutting tool to deepen the escape groove is conceivable, the inner ring wall thickness is reduced as described above.

(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 portions that are the same as or equivalent to those of the first embodiment are denoted by the same or equivalent reference numerals in the drawings, and description thereof is omitted or simplified.

  In the present embodiment, as shown in FIG. 3, after inserting the cutting tool B into the boundary portion between the inner ring raceway surface 12a and the large collar surface 16a at the conventional insertion angle θ2, the insertion angle θ2 of the cutting tool B is maintained. However, the cutting tool B is moved to the small flange 15 side in parallel with the inner ring raceway surface 12a. Thereby, like the said 1st Embodiment, the axial direction width W1 of the large collar side escape groove 18 is set larger than the radial direction width W2 of the large collar side relief groove 18. This machining method is applied when it is difficult to make the insertion angle of the cutting tool smaller than before, and machining by an NC lathe is assumed.

After inserting the cutting tool B into the inner ring raceway surface 12a near the boundary between the inner ring raceway surface 12a and the large collar surface 16a at the conventional insertion angle θ2, the cutting tool B is maintained while maintaining the insertion angle θ2 of the cutting tool B. The large flange side relief groove 18 may be formed by moving it toward the large flange portion 16 side in parallel with the inner ring raceway surface 12a.
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, in the present embodiment, the outer ring raceway surface, the inner ring raceway surface, and the rolling surfaces of the tapered rollers are formed in a linear shape, but are not limited thereto, and are not limited to a crowning shape (single arc shape, logarithmic shape, It may be formed in a shape of two or more arcs, a shape having a straight portion in the center of the raceway surface (rolling surface), and the like.

DESCRIPTION OF SYMBOLS 10 Tapered roller bearing 11 Outer ring 11a Outer ring raceway surface 12 Inner ring 12a Inner ring raceway surface 13 Tapered roller 13a Small diameter side end surface 13b Large diameter side end surface 14 Cage 15 Small collar 15a Small collar 16 Large collar 16a Large collar 17 Small bowl Side clearance groove 18 Large collar side clearance groove W1 Axial width of large collar side clearance groove W2 Radial width of large collar side clearance groove B Byte θ1 Byte insertion angle θ2 Byte insertion angle

Claims (2)

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, and a plurality of tapered rollers arranged to be rollable between the outer ring raceway surface and the inner ring raceway surface, Prepared,
The inner ring includes a small flange portion provided at a small diameter side end portion of the inner ring raceway surface, a large collar portion provided at a large diameter side end portion of the inner ring raceway surface, and a large size of the inner ring raceway surface and the large collar portion. A tapered roller bearing having a relief groove provided in a boundary portion with the flange surface,
A tapered roller bearing wherein the axial width of the relief groove is set larger than the radial width of the relief groove. 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, and a plurality of tapered rollers arranged to be rollable between the outer ring raceway surface and the inner ring raceway surface, Prepared,
The inner ring includes a small flange portion provided at a small diameter side end portion of the inner ring raceway surface, a large collar portion provided at a large diameter side end portion of the inner ring raceway surface, and a large size of the inner ring raceway surface and the large collar portion. A method of manufacturing a tapered roller bearing having a relief groove provided in a boundary portion with a flange surface,
The escape groove is formed by inserting a bite into the boundary portion,
The cone is formed by inserting the cutting tool into the boundary portion or the inner ring raceway surface near the boundary portion, and then moving the cutting tool while maintaining the insertion angle of the cutting tool to form the escape groove. A method of manufacturing a roller bearing.

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