JP2008169871A - Tapered roller bearing and inner ring machining method for tapered roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tapered roller bearing capable of improving the load capacity as compared with a bearing having the same size, minimizing an installation space as recently desired and being arranged at a portion to which large load is applied, and an inner ring machining method for a tapered roller bearing applicable to the tapered roller bearing. <P>SOLUTION: The tapered roller bearing has an inner ring 21, an outer ring 22, a plurality of tapered rollers 23 rollably arranged between the inner ring 21 and the outer ring 22, and a retainer 24 for retaining the tapered rollers 23 at predetermined intervals in the circumferential direction. A flange 26 is provided on the large diameter side of the inner ring 21 so as to project to the outer diameter side. The inner ring 21 has a raceway surface 25 lying from the flange 26 to the small diameter end. A recess part 27 having a curvature radius smaller than that of a round portion 28 at a large edge of the tapered roller 23 is formed at a corner portion between the flange 26 and the raceway surface 25. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tapered roller bearing and a method for processing an inner ring for a tapered roller bearing.

  The driving force of the engine in the automobile is transmitted to the wheels via a power transmission system including any or all of a transmission, a propeller shaft, a differential, and a drive shaft.

  In this power transmission system, a tapered roller bearing having a high load capacity against a radial load and excellent in impact resistance is often used as a bearing for supporting the shaft. As shown in FIG. 5, the tapered roller bearing generally has an inner ring 2 having a conical raceway surface 1 on the outer peripheral side, an outer ring 4 having a conical raceway surface 3 on the inner peripheral side, and an inner ring 2. And a plurality of tapered rollers 5 disposed between the outer ring 4 and the outer ring 4, and a retainer 6 that holds the tapered rollers 5 at a predetermined circumferential interval.

  In this tapered roller bearing, the tapered roller 5 and the raceway surfaces 1 and 3 of the inner and outer rings 2 and 4 are in line contact, and the inner and outer ring raceway surfaces 1 and 3 and the roller center O are at one point on the axis P (see FIG. (Not shown).

  For this reason, when a load is applied, the tapered roller 5 is pressed to the large end side, so that a flange 7 that protrudes toward the outer diameter side is provided on the large diameter side of the inner ring 2 to receive this load. It has been. In addition, a flange 8 that protrudes also to the small end side of the inner ring 2 is provided so that the tapered roller 5 does not fall off to the small end side before the bearing is assembled in a machine or the like.

Tapered roller bearings used in automobile differentials and transmissions have recently been increased in engine torque and multistage, and are often subjected to large loads in a small space. Therefore, there is a conventional technique in which the number of rollers is increased by reducing the clearance between the rollers, thereby increasing the load capacity (Patent Document 1). In addition, there is a type in which the load capacity is increased by increasing the roller length and the roller diameter.
JP 2005-351472 A

  By the way, the inner ring 2 of the tapered roller bearing is manufactured from a steel material through a process of forging → turning → heat treatment → grinding. Grinding is performed on the end surfaces 10 and 11, the inner diameter surface 12, the raceway surface 1, and the large flange surface 13 (the roller corresponding surface of the flange portion 7).

  That is, the raceway surface 1 is ground on the raceway surface 1 by a roller-shaped grinding body 15 as shown in FIG. Therefore, the corner portions of the raceway surface 1 and the flange portions 7 and 8 are provided with relief portions 16 and 17 in order to escape the peripheral portion of the grinding body (grinding stone) 15 and avoid interference with the tapered rollers 5. There was a need.

  The large ridge surface 13 is ground by a disc-shaped grinding body 18 as shown in FIG. For this reason, it is necessary to make the large-diameter side relief portion 16 large. That is, it is necessary to allow the grinding body 15 to escape and the grinding body 18 to escape. Therefore, as shown in FIG. 6, the shading portion 16 includes a main body portion 16 a having a circular bottom surface and a planar opening-side end surface portion 16 b extending from the opening portion on the track surface 1 side of the main body portion 16 a. The radius of curvature R of the relief portion 16 (that is, the main body portion 16a) is set larger than the radius of curvature r of the rounded portion (chamfered portion) 5a of the large edge of the tapered roller 5. In addition, the axial length A of the thin portion 16 is made larger than the axial length a of the large edge chamfered portion 5 a of the tapered roller 5, and the radial length B of the thin portion 16 is set to be large of the tapered roller 5. It is larger than the radial length b of the edge chamfered portion 5a.

  In this manner, if the thin portions 16 and 17 are provided on the large diameter side and the small diameter side of the raceway surface 1, the load capacity is reduced by the thin portions 16 and 17 minutes. In particular, since it is necessary to make the large-diameter side relief portion 16 large, the load capacity is greatly reduced.

  Further, by providing the flange portions 7 and 8 on the large diameter side and the small diameter side of the raceway surface 1, there is a restriction on the axial space (the raceway length and the roller length of the inner ring 2), and the roller length and the roller diameter. However, the load capacity within the same bearing size is limited.

  In view of the above problems, the present invention is capable of improving the load capacity compared to the same bearing size, and is a tapered roller bearing that can be disposed in a part that is requested in a small space and is loaded with a large load in recent years. And the processing method of the inner ring | wheel for tapered roller bearings which can be used for such a tapered roller bearing is provided.

  A tapered roller bearing according to the present invention includes an inner ring, an outer ring, a plurality of tapered rollers arranged to roll between the inner ring and the outer ring, and a cage that holds the tapered rollers at a predetermined circumferential interval. In a tapered roller bearing, a flange that protrudes toward the outer diameter on the large diameter side of the inner ring and receives the large end surface of the tapered roller is provided, and a raceway surface that reaches the small diameter end from the flange is formed. In this corner portion, a relief portion having a radius of curvature smaller than the radius of curvature of the rounded portion of the large end of the tapered roller is provided.

  According to the tapered roller bearing of the present invention, the raceway surface of the inner ring reaches the small diameter end from the collar portion, and the collar portion on the small diameter side of the inner ring, which has existed conventionally, is omitted. For this reason, it is possible to make a large ridge portion and raceway surface to be omitted. Further, by omitting the small diameter side flange portion, the small diameter side hollow portion can also be omitted, and the corner portion provided between the flange portion and the raceway surface has a large radius of curvature of the tapered roller. It is smaller than the radius of curvature of the rounded portion of the edge, and further, the axial length of the shading portion is made smaller than the axial length of the chamfered portion of the large edge of the tapered roller, and the radial length of the shading portion is made smaller. By making it smaller than the radial length of the chamfered portion of the large end edge of the tapered roller, the amount of decrease in the raceway surface due to the shading portion is small.

  The processing method of the inner ring for the tapered roller bearing is a processing method of the inner ring for the tapered roller bearing in which a flange portion protruding to the outer diameter side is provided on the large diameter side, and a raceway surface extending from the flange portion to the small diameter end is formed. The outer ring surface of the inner ring material is formed after forming an inner ring material including a main body portion of a short cylindrical body whose outer diameter surface is a tapered surface and a flange portion provided on the larger diameter side of the outer diameter surface of the main body portion. And the small diameter side end face of the flange part are ground at the same time, and the ground outer diameter surface is used as the raceway surface, and the small diameter side end face of the ground flange part is used as the large end face corresponding surface of the tapered roller.

  According to the method of processing an inner ring for a tapered roller bearing according to the present invention, the outer diameter surface of the inner ring material and the small-diameter side end face of the flange part are ground simultaneously. There is no need to use two types of grinding wheels. For this reason, the relief part for escape of the grinding stone to be formed can be reduced. In addition, during grinding, the small diameter end of the inner ring material does not have a flange, so the grinding wheel is not restricted by the axial length.

  In the tapered roller bearing of the present invention, the raceway surface can be made large only in the flange portion and the thinning portion that are omitted, and the thinning portion provided on the large diameter side is small, and the amount of decrease in the raceway surface due to the thinning portion is small. For this reason, the raceway surface can be made as large as possible, the axial center length of the tapered roller can be increased, and the load capacity can be improved. That is, if this bearing is used, it will be suitable when it arrange | positions in the site | part to which a big load is loaded in a small space.

  In the method for processing an inner ring for a tapered roller bearing according to the present invention, since two types of a grinding wheel for raceway surface grinding and a grinding wheel for saddle grinding are not used, a relief portion for escaping the grinding wheel can be reduced. For this reason, in combination with the fact that the raceway surface can be made large and the small-diameter end of the inner ring material does not have a flange portion and a hollow portion, if this processed inner ring is used for a tapered roller bearing, the load capacity Can be improved.

  In addition, when grinding, the small diameter end of the inner ring material does not have a flange portion or a thinning portion, so the grinding wheel is not restricted by the axial length, and various sizes of grinding wheels can be used, reducing costs. Can be achieved.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 shows a tapered roller bearing according to the present invention. The tapered roller bearing includes an inner ring 21, an outer ring 22, a plurality of tapered rollers 23 disposed between the inner ring 21 and the outer ring 22 so as to be freely rollable, And a retainer 24 that holds the tapered rollers 23 at predetermined circumferential intervals.

  The inner ring 21 has a conical raceway surface 25 on its outer diameter surface, and a flange portion 26 is formed on the larger diameter side of the raceway surface 25 so as to protrude toward the outer diameter side. That is, the raceway surface 25 is formed from the flange portion 26 to the small diameter end, and does not have a flange portion (small flange) on the small diameter side like the inner ring of the conventional tapered roller bearing. For this reason, the slack portion 27 is formed only in the corner portion between the raceway surface 25 and the flange portion 26. The flange portion 26 in this case is a large flange that receives the axial load through the tapered roller 23 and guides the tapered roller 23 to rotate. Further, the conventionally provided gavel does not play a special role during the rotation of the bearing, and such a thing is omitted in the present invention.

  As shown in FIG. 3, the thinning portion 27 includes a main body portion 27 a having a circular bottom surface and planar opening-side end surfaces 27 b and 27 c extending from the opening end portion of the main body portion 27 a. Then, the size of the thin portion 27 is made smaller than that of the conventional one shown in FIG. That is, the relief portion 27 has a radius of curvature R 1 (a radius of curvature of the main body portion 27 a) set smaller than a radius of curvature r of the rounded portion (chamfered portion) 28 of the large end edge of the roller 23. In addition, the axial length A1 of the thin portion 27 is made smaller than the axial length a1 of the large edge chamfered portion 28 of the tapered roller 23, and the radial length B1 of the thin portion 27 is set to be large. The edge chamfered portion 28 is smaller than the radial length b1. That is, a1> A1, b1> B1, and r> R.

  The outer ring 22 has a tapered raceway surface 30 on its inner diameter surface, and a plurality of tapered rollers 23 held by a cage 24 roll on the raceway surface 30 and the raceway surface 25 of the inner ring 21. . The tapered roller 23 and the raceway surfaces 25 and 30 of the inner and outer rings 21 and 22 are in line contact, and the inner and outer ring raceway surfaces 21 and 22 and the roller center O coincide with a point (not shown) on the axis P. Designed as

  Further, as shown in FIG. 2, the cage 24 includes a pair of annular portions 24a and 24b, and pillar portions 24c that extend in the roller center O direction at equal circumferential positions and connect the annular portions 24a and 24b. . And the tapered roller 23 is rotatably accommodated in the pocket 24d partitioned by the column parts 24c and 24c which adjoin along the circumferential direction. The cage 24 may be manufactured by pressing a steel plate or may be a molded synthetic resin material.

  Since the tapered roller bearing thus configured does not have a flange on the small diameter side of the inner ring 21, the small end surface 23c of the tapered roller 23 is replaced with the small diameter side end surface 21b of the inner ring 21, as shown in FIG. Can be extended until

  Next, a method for processing the inner ring 21 of the tapered roller bearing will be described. That is, the inner ring 21 is manufactured from a steel material through a process of forging → turning → heat treatment → grinding. Grinding is performed on the end surfaces 21a and 21b, the inner diameter surface 31, the raceway surface 25, and the flange surface 26a (the roller corresponding surface of the flange portion 26).

  That is, before grinding, as shown in FIG. 4, a main body portion 36 of a short cylinder whose outer diameter surface 35 is a tapered surface, and a flange portion 37 provided on the larger diameter side of the outer diameter surface of the main body portion 36, The inner ring | wheel raw material 38 provided with is formed. In the inner ring material 38, a thin portion 27 is formed at a corner portion between the outer diameter surface 35 and the flange portion 37.

  In this case, the outer diameter surface 35 and the small diameter side end surface 37 a of the flange portion 37 are ground by a single grinding tool (grinding grindstone) 33. The grinding wheel 33 includes a raceway surface grinding portion 33a for grinding the outer diameter surface 35, and a saddle surface grinding portion 33b for grinding the small diameter side end surface 37a. That is, the raceway surface grinding portion 33a and the heel surface grinding portion 33b are set to have the same angle γ as the angle formed between the raceway surface 25 of the inner ring 21 and the heel surface 26a.

  For this reason, the outer diameter surface 35 and the small diameter side end surface 37a are ground at the same time by rotating the grinding wheel 33 around the axis O1. As a result, the outer diameter surface 35 becomes the raceway surface 25 of the inner ring 21, and the small diameter side end surface 37 a becomes the flange surface 26 a of the inner ring 21, thereby forming the inner ring 21.

  In the tapered roller bearing of the present invention, the raceway surface 25 of the inner ring 21 reaches the end of the small diameter from the flange portion 26, and the flange portion and the thinning portion on the small diameter side of the inner ring 21 that existed in the prior art are omitted. It is. For this reason, it is possible to make the raceway surface 25 large only in the omitted collar portion and the missing portion. In addition, the corner portion 27 of the flange portion 26 and the raceway surface 25 has a radius of curvature r smaller than the radius of curvature R of the large end edge (chamfered portion) 28 of the tapered roller 23. Since a1> A1 and b1> B1, the amount of decrease in the raceway surface 25 due to the provision of the loose portion 27 is small compared to the conventional tapered roller bearing as shown in FIG.

  For this reason, the raceway surface becomes larger than the conventional inner ring for tapered roller bearings of the same size, and the length of the axial center of the tapered roller 23 can be increased and the load capacity can be improved. By eliminating the collar part and fillet part on the small diameter side and increasing the roller length (roller axial length), the load capacity is improved by about 10% to 20% compared to conventional tapered roller bearings of the same size. Can be made. That is, if this bearing is used, it will be suitable when it arrange | positions in the site | part to which a big load is loaded in a small space.

  In the processing method of the inner ring for the tapered roller bearing, the outer diameter surface 35 of the inner ring material 38 and the small-diameter side end surface 37a of the flange portion 37 are ground at the same time. There is no need to use two types of wheels. For this reason, the relief portion 27 for escaping the grinding wheel to be formed can be reduced. For this reason, in combination with the fact that the raceway surface 25 can be made large and that the small diameter end of the inner ring material 38 does not have a flange portion and a thinning portion, if this processed inner ring 21 is used for a tapered roller bearing. , Load capacity can be improved.

  In addition, during grinding, the small diameter end of the inner ring material 38 does not have a flange, so that the grinding wheel is not restricted by the axial length. For this reason, grinding wheels of various sizes can be used, and cost reduction can be achieved.

  By the way, since there is no flange on the small diameter side of the inner ring 21, the tapered roller 23 may fall off to the small end side before the bearing is assembled in a machine or the like. For this reason, it is preferable to provide the cage with a hook portion that engages with the flange portion on the large diameter side so that the tapered roller 23 does not fall. In this case, it is necessary to form a notch or the like on which the hook is hooked on the large-diameter flange, but when this notch is formed, it does not affect the raceway surface 25 side of the inner ring 21, and the present invention It does not affect the configuration and the operational effects based on this configuration.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the present invention may be used in a single row or in multiple rows. Further, this tapered roller bearing can be used in various parts where a tapered roller bearing can be conventionally used. In particular, it is preferable to use it for an automobile differential or transmission because it can cope with an increase in engine torque and multi-stages.

It is sectional drawing of the tapered roller bearing which shows embodiment of this invention. It is a simplified perspective view of the retainer of the tapered roller bearing. It is a principal part expanded sectional view of the said tapered roller bearing. It is sectional drawing which shows the inner ring processing method of the said tapered roller bearing. It is sectional drawing of the conventional tapered roller bearing. It is a principal part expanded sectional view of the conventional tapered roller bearing. It is sectional drawing which shows the processing method of the raceway surface of the inner ring | wheel of the conventional tapered roller bearing. It is sectional drawing which shows the processing method of the collar part of the inner ring | wheel of the conventional tapered roller bearing.

Explanation of symbols

21 Inner ring 22 Outer ring 23 Tapered roller 24 Cage 25 Raceway surface 26a Small-diameter side end surface 27 Nursing portion 28 Round portion 35 Outer-diameter surface 36 Main body portion 37 Gutter portion 37a Small-diameter side end surface 38 Inner ring material

Claims (2)

In a tapered roller bearing comprising an inner ring, an outer ring, a plurality of tapered rollers arranged to roll between the inner ring and the outer ring, and a cage that holds the tapered rollers at a predetermined circumferential interval,
Providing a collar part that protrudes to the outer diameter side on the large diameter side of the inner ring and receives the large end face of the tapered roller, forms a raceway surface that reaches the small diameter end from this collar part, and at the corner part of the collar part and the raceway surface, A corner portion having a radius of curvature smaller than the radius of curvature of the large edge chamfered portion of the tapered roller is provided, and the axial length of the inner ring corner portion is made smaller than the axial length of the large edge chamfered portion of the tapered roller. In addition, a tapered roller bearing characterized in that the radial length of the tapered portion is smaller than the radial length of the chamfered portion of the large edge of the tapered roller. A method of processing an inner ring for a tapered roller bearing in which a flange portion protruding to the outer diameter side is provided on the large diameter side, and a raceway surface reaching the small diameter end from the flange portion is formed,
After forming an inner ring material including a main body portion of a short cylinder whose outer diameter surface is a tapered surface and a flange provided on the larger diameter side of the outer diameter surface of the main body portion, the outer diameter surface of the inner ring material And a small-diameter side end face of the flange part, and the ground outer diameter surface is used as a raceway surface, and the small-diameter side end face of the ground flange part is a surface corresponding to the large end face of a tapered roller. Processing method for inner ring for roller bearings.

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