JP2007198518A - Roller and roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve workability, reduce cost, prevent the occurrence of an edge stress and achieve long service life by uniforming an axial surface pressure distribution without increasing the drop amount of crowning even when being utilized under high load in a cylindrical roller bearing or a conical roller bearing. <P>SOLUTION: A roller 4 is formed to be hollow or provided with dents 5, 6 in a side end surface thereof so as to lower the rigidity of a roller end. By so doing, the occurrence of an edge stress of the roller end is prevented. At least one of the rolling surface 4a of the roller 4, the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3 is provided with crowning so as to uniform an axial surface pressure distribution. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a roller shape of a cylindrical roller bearing or a tapered roller bearing, and a roller bearing provided with the roller.

In order to extend the rolling fatigue life of a roller bearing such as a cylindrical roller bearing or a tapered roller bearing, it is necessary to reduce the contact surface pressure with the rolling surface at the raceway surface of the inner and outer rings. In order to reduce the contact surface pressure under a certain load, it is important to make the surface pressure distribution uniform in the axial direction. As a technique, the raceway surface of the inner ring or outer ring of the roller bearing or the rolling surface of the roller is curved. The crowning process to be formed is known.
There have been many proposals for crowning in the past. Typical examples include Patent Documents 1 to 10.

In addition, a device has been devised in which a roller is made hollow or a deep recess is provided in a side end portion of the roller so that the roller has flexibility (for example, Patent Documents 11 and 12).
No. 02554882 (No. 5-22845) Japanese Utility Model Publication No. 5-89943 JP-A-8-232960 Japanese Patent Application Laid-Open No. 2000-257637 JP 2000-346078 A Japanese Unexamined Patent Publication No. 2001-65574 (US6390685B1) JP 2001-82114 A (US6311660B1) Japanese Patent Laid-Open No. 2001-124089 JP 2001-241446 A Japanese Patent Laid-Open No. 2002-235749 Japanese Utility Model Publication No. 1-128022 British Patent 181156

  In cylindrical roller bearings or tapered roller bearings, one of the inner ring raceway surface, the outer ring raceway surface, and the roller rolling surface is usually used in order to avoid edge stress at the roller end and to keep the axial surface pressure distribution constant. Several are crowned. However, when these roller bearings are used under a large load, there has been a problem that the amount of crowning drop has to be increased and the processing is difficult.

  Further, in Patent Document 11 and Patent Document 12, since no crowning is provided on any of the inner ring raceway surface, the outer ring raceway surface, and the roller rolling surface, the roller and the inner ring or the outer ring are in contact with each other at the roller end portion. There was a problem that edge stress was generated.

  In particular, as shown in FIG. 7, when the tapered roller bearing 11 is used in a front combination and a radial load W acts on the shaft 20, edge stress tends to occur on the large diameter side of the roller 14 due to the deflection of the shaft 20. On the contrary, as shown in FIG. 8, when the tapered roller bearing 11 is used in combination with the back surface and a radial load W acts on the shaft 20, edge stress is generated on the small diameter side of the roller 14 due to the deflection of the shaft 20. Cheap.

The object of the present invention is to make the axial surface pressure distribution uniform without increasing the amount of crowning drop even when used under a large load in a cylindrical roller bearing or a tapered roller bearing, It is to improve the workability and realize low cost while preventing the generation of edge stress and extending the life.
Another object of the present invention is to prevent the occurrence of edge stress due to the deflection of the shaft and extend the life when the tapered roller bearing is used in a front combination or a back combination.

In the roller of the present invention, the roller is made hollow, or a recess is provided on the side end surface of the roller, and a crowning is provided on the rolling surface of the roller.
By making the roller hollow or providing a recess on the side end face of the roller, the rigidity of the roller end portion is lowered and the stress is relieved. Therefore, even if the amount of the crowning drop on the roller rolling surface is small, the edge stress generated at the roller end can be kept small, and the life can be extended. The process of hollowing the rollers or providing the depressions on the side end surfaces of the rollers is not as precise as the process of crowning with a large drop amount, and therefore is easy to process and can be produced at low cost.

The roller bearing according to the present invention is such that the roller is hollow or a recess is provided in the side end surface of the roller, and at least one of the rolling surface of the roller, the raceway surface of the inner ring, and the raceway surface of the outer ring. A crowning was provided.
Since the roller used for the roller bearing according to the present invention is hollow or provided with a depression on the side end face, the rigidity of the roller end portion is reduced as described above, and the stress is relieved. Therefore, even if the amount of crowning on the roller rolling surface, the inner ring raceway surface, and the outer ring raceway surface is small, the edge stress generated at the roller end can be kept small, and the bearing life can be extended.

For tapered roller bearings used in front combination and used in applications where radial load is applied to the shaft between the front combination bearings, recesses are provided on the side end faces on both sides of the rollers to reduce the thickness around these recesses. The roller large diameter side was made thinner than the roller small diameter side, or crowning was provided on the rolling surface of the roller, and the drop amount of the crowning was made larger on the roller large diameter side than on the roller small diameter side.
When tapered roller bearings are used in a front combination, edge stress tends to occur on the large diameter side of the rollers due to shaft deflection. Therefore, by making the wall thickness around the depressions provided on the side end surfaces on both sides of the roller thinner on the large roller side than on the small roller side, the end on the large roller side is more than the end on the small roller side. However, the degree of reduction in rigidity is increased to prevent the occurrence of edge stress at the end portion on the large diameter side of the roller. Alternatively, the amount of drop of the crowning provided on the rolling surface of the roller is made larger on the roller large diameter side than on the roller small diameter side, thereby preventing the occurrence of edge stress at the end of the roller large diameter side.

For tapered roller bearings that are used in the back combination and are used in applications where a radial load is applied to the shaft between the back combination bearings, recesses are provided on the side end surfaces of both sides of the roller to reduce the thickness around these recesses. The roller small diameter side was made thinner than the roller large diameter side, or crowning was provided on the rolling surface of the roller, and the drop amount of the crowning was made larger on the roller small diameter side than on the roller large diameter side.
When tapered roller bearings are used in combination on the back side, edge stress tends to occur on the small diameter side of the rollers due to shaft deflection. Therefore, by making the wall thickness around the dents provided on the side end faces on both sides of the roller thinner on the roller small diameter side than on the roller large diameter side, the roller small diameter side end is closer to the roller large diameter end. However, the degree of reduction in the rigidity is increased to prevent the occurrence of edge stress at the end portion on the small diameter side of the roller. Alternatively, the amount of drop of the crowning provided on the rolling surface of the roller is made larger on the roller small diameter side than on the roller large diameter side, thereby preventing the occurrence of edge stress at the end portion on the roller small diameter side.

  The roller bearing according to the present invention is such that the roller is hollow or a recess is provided in the side end surface of the roller, and at least one of the rolling surface of the roller, the raceway surface of the inner ring, and the raceway surface of the outer ring. The crowning is provided, so even when used under heavy loads, the axial surface pressure distribution can be made uniform without increasing the amount of crowning drop, improving workability and reducing costs. However, it is possible to prevent the generation of edge stress and extend the life.

  The tapered roller bearing according to the present invention is used in a front combination, and when a radial load is applied to the shaft between the front combination bearings, recesses are provided on the side end surfaces on both sides of the roller, and the thickness around these recesses is increased. The roller large diameter side is made thinner than the roller small diameter side, or a crown is provided on the rolling surface of the roller, and the roller large diameter side is made larger than the roller small diameter side with respect to the amount of drop of the crown, and the back surface When used in a combination and in applications where radial load is applied to the shaft between the bearings of the rear combination, recesses are provided on the side end faces on both sides of the roller, and the thickness around these recesses is reduced to the roller small diameter. The roller side is made thinner than the roller large diameter side, or the roller rolling surface is provided with a crowning, and the amount of the crowning drop is made larger on the roller small diameter side than on the roller large diameter side. Preventing the occurrence of stress, it is possible to increase the life of.

A first embodiment of the present invention will be described with reference to FIGS.
The bearing 1 is a cylindrical roller bearing and includes an inner ring 2, an outer ring 3, and a plurality of substantially cylindrical rollers 4 interposed between the inner and outer rings 2 and 3, as shown in FIG. . The inner ring 2 has a raceway surface 2a formed of a cylindrical surface on the outer periphery, and has flanges 2b and 2c on both sides of the raceway surface 2a. The outer ring 3 is formed with a raceway surface 3a opposite to the raceway surface 2a of the inner ring 2 on the inner periphery, and has no wrinkles. The outer periphery of the roller 4 is formed as a rolling surface 4a, and the roller 4 can freely roll between both the raceway surfaces 2a and 3a. Each roller 4 is put in a pocket of a cage (not shown) and held at a predetermined interval in the circumferential direction.
The flanges 2b and 2c may be on the outer ring 3 instead of the inner ring 2. The flanges 2b and 2c may be disposed only on one side of the inner ring 2 or the outer ring 3.

  As shown in the sectional view of FIG. 2, in the roller 4, the axial center portion 4aa of the roller rolling surface 4a is linear, and crowning is formed at both axial end portions 4ab and 4ac. The crowning is formed by an arcuate curve (radius r), and the drop amount σ of the crowning at both ends of the roller 4 is equal. The drop amount σ referred to here is the difference between the maximum radius of the roller 4 and the radius of the roller 4 at the end of the effective length (intersection of the rolling surface 4a and the chamfers 4b and 4c). Chamfers 4b and 4c are provided at both ends of the roller rolling surface 4a.

  Further, recesses 5 and 6 having a circular cross section (not shown) are provided on both end surfaces of the roller 4. Both indentations 5 and 6 have the same diameter and the same depth. Therefore, the wall thickness t around the depressions 5 and 6 is equal on both the small diameter side and the large diameter side.

  As described above, when the crowning is provided on the rolling surface 4a of the roller 4, the unevenness of the load acting on the contact surfaces of the inner and outer rings 2, 3 with the raceway surfaces 2a, 3a and the rolling surface 4a of the four is reduced. be able to. Moreover, if the dents 5 and 6 are provided in the side end surface of the roller 4, the rigidity of the axial direction edge part of the roller 4 will fall, and stress will be relieved. Therefore, the amount of crowning drop σ and the thickness t around the recesses 5 and 6 are optimally set and combined, so that the amount of crowning drop σ is not increased and can be produced at relatively low cost with relatively easy processing. However, the surface pressure distribution can be made uniform in the axial direction, and the life can be extended.

A second embodiment of the present invention will be described with reference to FIGS.
The bearing 11 is a tapered roller bearing and includes an inner ring 12, an outer ring 13, and a plurality of tapered rollers 14 interposed between the inner and outer rings 12, 13 as shown in FIG. The inner ring 12 is formed with a raceway surface 12a formed of a conical surface on the outer periphery, and has a large collar 12b and a small collar 12c on the large diameter side and the small diameter side of the raceway surface 12a, respectively. The outer ring 13 is formed with a raceway surface 13a facing the raceway surface 12a of the inner ring 12 on the inner periphery, and has no wrinkles. The outer circumference of the tapered roller 14 is formed as a rolling surface 14a, and is freely rollable between the raceway surfaces 12a and 13a. Each tapered roller 14 is put in a pocket of a cage (not shown) and held at a predetermined interval in the circumferential direction.

  As shown in the sectional view of FIG. 4, an arcuate (radius r) full crowning is formed on the rolling surface 14 a of the tapered roller 14. In another example, the central portion of the rolling surface 14a may be formed in a straight line and crowned only at both ends. The crowning drop amounts σ1 and σ2 can be set to appropriate values according to the situation and application in which the tapered roller bearing 14 is used. Chamfers 14aa and 14ab are provided at both ends of the roller rolling surface 14a.

  Further, recesses 15 and 16 having a circular cross section (not shown) are provided on both end surfaces of the tapered roller 14. Appropriate values can be set for the thicknesses t1 and t2 around the recesses 15 and 16 depending on the situation and application in which the tapered roller bearing 14 is used.

Similarly to the first embodiment, when the crowning is provided on the rolling surface 14a of the roller 14, the load acting on the contact surface with the raceway surfaces 12a and 13a of the inner and outer rings 12 and 13 and the rolling surface 14a of 14 is obtained. The bias can be reduced, and if the depressions 15 and 16 are provided on the side end surfaces of the rollers 14, the rigidity of the end portions in the axial direction of the rollers 14 is reduced, and the stress is relieved. Therefore, the crowning drop amounts σ1 and σ2 and the thicknesses t1 and t2 around the recesses 15 and 16 are optimally set and combined, so that the crowning drop amounts σ1 and σ2 are not increased and the processing is relatively easy. Although it can be produced at a low cost, the surface pressure distribution can be made uniform in the axial direction and the life can be extended.
Further, by setting the crowning drop amounts σ1, σ2 or the thicknesses t1, t2 around the depressions 15 and 16 to different values, it is possible to cope with the phenomenon that the stress distribution becomes non-uniform under misalignment. it can.

  For example, as shown in FIG. 7, when the tapered roller bearing 11 is used in a front combination and a radial load W acts between the bearings, edge stress is generated on the large diameter side of the roller 14 due to the deflection of the shaft 20. Therefore, the thickness around the depressions 15 and 16 is set so that the roller large diameter side is smaller than the roller small diameter side, that is, t1 <t2, or the drop amount of the crowning is set so that the roller large diameter side is larger than the roller small diameter side. That is, by making σ1> σ2, generation of edge stress on the large diameter side of the roller 14 is prevented, and the contact surface pressure is made uniform.

  Also, as shown in FIG. 8, when the tapered roller bearing 11 is used in combination with the back surface and a radial load W acts between the bearings, edge stress is generated on the small diameter side of the roller 14 due to the deflection of the shaft 20. The thickness around the recesses 15 and 16 is set such that the roller small diameter side is smaller than the roller large diameter side, that is, t2 <t1, or the crowning drop amount is set such that the roller small diameter side is larger than the roller large diameter side, That is, by setting σ2> σ1, generation of edge stress on the small diameter side of the roller 14 is prevented, and the contact surface pressure is made uniform.

In the first and second embodiments, the crowning shape is an arc shape having a single curvature, but the crowning shape is expressed by a continuous arc shape formed by a plurality of arcs or a logarithmic curve. It may be a shape or a shape expressed by a general function.
In the first and second embodiments, although the crowning is provided on the rolling surfaces 4a and 14a of the rollers 4 and 14, the raceway surfaces 2a and 12a of the inner rings 2 and 12, and the raceway surfaces 3a and 12 of the outer rings 3 and 13, respectively. You may provide a crowning to 13a. In some cases, crowning may be provided on the rolling surfaces 4a and 14a of the rollers 4 and 14, the raceway surfaces 2a and 12a of the inner rings 2 and 12, and the raceway surfaces 3a and 13a of the outer rings 3 and 13.

  Furthermore, in 1st and 2nd embodiment, it was set as the structure which provided the dent 5,6,15,16 in the side end surface of the rollers 4,14, However, As shown in FIG. 5, FIG. The rollers 4 and 14 may be hollow by providing communication holes 7 and 17 connecting the side end surfaces on both sides. In that case, the same operation and effect as the case where the depression is provided can be obtained.

It is sectional drawing which abbreviate | omitted a part of cylindrical roller bearing concerning 1st Embodiment of this invention. It is sectional drawing of the roller of the cylindrical roller bearing. It is sectional drawing which abbreviate | omitted a part of tapered roller bearing concerning 2nd Embodiment of this invention. It is sectional drawing of the roller of the same tapered roller bearing. It is sectional drawing of the roller of a different cylindrical roller bearing. It is sectional drawing of the roller of a different tapered roller bearing. It is a figure which shows the state which uses a tapered roller bearing by front combination. It is a figure which shows the state which uses a tapered roller bearing by a back surface combination.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylindrical roller bearing 2, 12 ... Inner ring 2a, 12a ... Inner ring raceway surface 3, 13 ... Outer ring 3a, 13a ... Outer ring raceway surface 4, 14 ... Roller 4a, 14a ... Roller rolling surface 5, 6, 15, 16 ... Indentations 7, 17 ... Communication holes 11 ... Tapered roller bearings t, t1, t2 ... Thickness σ, σ1, σ2, ... Crowning drop amount around the indentations

Claims (4)

  A roller of a roller bearing in which a roller is hollowed or a recess is provided on a side end surface of the roller, and a crowning is provided on a rolling surface of the roller.   A roller bearing in which a roller is hollowed or a recess is provided on a side end surface of the roller, and crowning is provided on at least one of a rolling surface of the roller, a raceway surface of the inner ring, and a raceway surface of the outer ring.   In tapered roller bearings used in front combination and used in applications where radial load acts on the shaft between the front combination bearings, recesses are provided on the side end faces of both sides of the rollers, and the thickness around these recesses is Tapered roller bearings in which the roller large-diameter side is made thinner than the roller small-diameter side, or the roller rolling surface is provided with a crowning, and the amount of drop in the crowning is greater on the roller large-diameter side than on the roller small-diameter side.   In tapered roller bearings used in applications where a radial load is applied to the shaft between the bearings of the rear combination and the rear combination, recesses are provided on the side end surfaces on both sides of the roller, and the thickness around these recesses is reduced. Tapered roller bearings in which the roller small diameter side is made thinner than the roller large diameter side, or the roller rolling surface is provided with a crowning, and the amount of drop of the crowning is larger on the roller small diameter side than on the roller large diameter side.

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