JP3877004B2 - Double row cylindrical roller bearing - Google Patents

Description

  The present invention relates to a double-row cylindrical roller bearing, and particularly supports a rotating body that rotates at high speed under lubrication with a small amount of grease or lubricating oil, such as a shaft driven by a motor or a main shaft of a machine tool. The present invention relates to a synthetic resin cage incorporated in a double row cylindrical roller bearing which is required to have low heat generation below.

Conventionally, a bearing that rotatably supports a spindle of a machine tool is required to have characteristics of high rigidity, high rotational accuracy, and low heat generation in order to maintain machining accuracy.
From the viewpoint of high rigidity, cylindrical roller bearings are generally used as bearings for machine tools. However, due to the demand for improved productivity, which has been rapidly increasing in recent years, it can withstand high-speed rotation, has a long service life, There is a need for double row cylindrical roller bearings.

A so-called machined cage made of a copper alloy is used for a conventional cylindrical roller bearing cage, but when used at high speed rotation, the inner and outer peripheral surfaces of the cage and the inner surface of the pocket are used to rotate the inner ring and outer ring. There was a drawback that abrasion powder was generated due to contact with the moving surface and the cylindrical roller. When the wear powder is mixed in the grease, there is a problem that the lubricating performance is remarkably deteriorated to cause seizure or damage.
In recent years, a cage made of synthetic resin has begun to be adopted as a cage that solves the above problems. The cage made of synthetic resin is formed by injection molding a material in which an appropriate amount of a reinforcing material such as glass fiber is mixed in a synthetic resin such as polyamide resin.

  Although the cage made of synthetic resin is excellent in wear resistance, it is inferior in rigidity and strength compared to a cage made of metal, and when used in a bearing that rotates at high speed, the force acting on the cage There was a possibility of damage.

Therefore, in Japanese Patent Application Laid-Open No. 11-166544, as shown in FIGS. 31 and 32, a large number of cantilever-shaped column portions 1b are laterally arranged at predetermined intervals from an annular portion 1a formed in a ring shape. There has been proposed a cage 1 made of a synthetic resin provided to project.
In this publication, a cylindrical roller 2 that uses a synthetic resin cage 1 and is rotatably held in a pocket portion between adjacent column portions 1b is arranged between an outer ring 3 and an inner ring 4 so as to roll freely. A double row cylindrical roller bearing 5 is disclosed.

  The cage 1 made of synthetic resin of the double row cylindrical roller bearing 5 utilizes the elasticity of the synthetic resin when excessive circumferential force acts on the column portion 1b from the cylindrical roller 2 with high speed rotation. The excessive force is absorbed by the elastic deformation of the column portion 1b to prevent the cage 1 from being damaged.

  In the conventional cage 1, when the bearing 5 rotates at a high speed, a large centrifugal force proportional to the square of the rotation speed acts on the cage 1, and as shown in FIG. Displacement is made in the direction of the arrow B (outer diameter direction), and accordingly, the annular portion 1a is twisted and the cage 1 is elastically deformed.

  The inner ring guide type retainer 1 shown in FIG. 33 is formed by elastic deformation of the outer surface 1c of the annular part 1a, the outer surface 1c side of the inner part, the inner ring 4, and the annular part 1a. The inner diameter side of the inner side surface 1d and the side surface of the cylindrical roller 2 interfere with each other and are strongly pressed. Since this pressing force is proportional to the square of the rotation speed, the higher the rotation speed, the larger the geometric series and the greater the force.

  If these parts continue to rotate at a high speed while being strongly pressed, heat is generated by friction, and deterioration of the encapsulated grease or lubricating oil is promoted to lower the lubricating performance. Further, there is a problem that the contact portion of the cage 1, the inner ring 4 or the cylindrical roller 2 is locally worn and the life of the bearing is shortened.

  Also, in the outer ring guide type or roller guide type cage, the interference part is different from the inner ring guide type cage, but similar interference occurs due to elastic deformation of the cage due to centrifugal force, There were serious problems such as heat generation and wear.

  In addition, the torque may fluctuate due to interference of each component, which may hinder the stabilization of rotation accuracy.

  Therefore, the present invention has been made in view of the above problems, and even when the cage is elastically deformed by centrifugal force acting on the cage during high-speed rotation, occurrence of interference between the cage, the inner ring, and the rollers. An object of the present invention is to provide a long-life double-row cylindrical roller bearing that is resistant to high-speed rotation with a small amount of lubricant and that generates little heat.

  As a result of intensive studies by the inventors, the rigidity of the cage made of synthetic resin can be improved, and at high speed rotation of dmN (dm: pitch circle diameter, N: shaft rotation speed) of 1 million or more. It was also found that the heat generation of the bearing can be remarkably suppressed.

  The object according to the present invention is provided for each row of an outer ring, an inner ring, a cylindrical roller arranged in a double row so as to roll between the outer ring and the inner ring, and the double row cylindrical roller. A plurality of roller guides that are integrally formed of a synthetic resin, each having a ring-shaped ring portion and a plurality of column portions that protrude in the axial direction at predetermined intervals in the circumferential direction from the roller side end surface of the ring portion A cylindrical retainer, and the cylindrical rollers are held in a plurality of pocket portions constituted by both side surfaces facing each other in the circumferential direction of the adjacent column portions and roller side end surfaces of the annular portions. A double-row cylindrical roller bearing, wherein the back surface of the annular portion opposite to the roller side end surface is continuous from the flat surface formed on the inner diameter side and the flat surface, and the shaft of the annular portion Inclining in the range of 1 to 10 degrees from the inner diameter side to the outer diameter side so as to gradually reduce the dimensional dimension, A taper surface having a radial length longer than a radial length of the carrier surface, and the back surface is opposed to the back surface of the roller guide type retainer in an adjacent row and has an inner diameter between the back surface A gap extending from the side toward the outer diameter side, and when the free end side of the column portion is bent in the diameter-expanding direction by centrifugal force, the gap allows elastic deformation of the annular portion. The outer peripheral surface of the pillar portion has a tapered surface that gradually decreases in diameter toward the tip in the axial direction so as to gradually reduce the radial dimension of the pillar portion, and faces the circumferential direction of the pillar portion. Both side surfaces are provided with a roller holding portion that restricts the radial position of the cage itself by contacting with the cylindrical roller, and at least part of the range on the inner diameter side of the pitch circle diameter of the cylindrical roller, the centrifugal force The cylindrical roller when the free end side of the column portion is bent in the diameter expansion direction by It is achieved by a double row cylindrical roller bearing characterized by having a straight surface that does not act on the contact pressure in the bearing radial direction.

  The above synthetic resin cage is made of, for example, a thermoplastic synthetic resin such as polyamide 66, polyamide 46, polyphenylene sulfide, polyacetal or the like as a base material, and about 10 to 30% by weight of glass fiber added for strength improvement. It can be formed by injection molding. However, when a sufficient elasticity is required for the cage made of synthetic resin depending on the application, it may be considered that an additive such as glass fiber is not added. The thermoplastic synthetic resin used as the base material is, in the case of a synthetic resin cage for a cylindrical roller bearing for supporting a main spindle for a general machine tool, in terms of price, strength, chemical From the viewpoint of functional aspects such as mechanical stability, polyamide 66 is preferred. On the other hand, when the temperature conditions during normal operation or running-in operation become extremely severe (high temperature), or when better fatigue strength and rigidity are required, polyamide 46 has a high temperature, chemical resistance, humidity ( Polyphenylene sulfide is preferable when dimensional stability against moisture absorption is particularly required, and polyacetal is particularly preferable when abrasion resistance is particularly required.

  In this double row cylindrical roller bearing, even if the bearing is rotated at a high speed, the tip of the column part is displaced radially outward by centrifugal force, and the ring part is twisted and retained even if the cage is elastically deformed. Interference between the cages, the cage and the raceway can be avoided. In addition, heat generation and torque fluctuation due to friction can be reduced, and local wear can be prevented. Therefore, it is possible to obtain a long-life double-row cylindrical roller bearing that can endure high-speed rotation stably for a long period of time with a small amount of lubricant and has little torque fluctuation.

  Further, the object of the present invention is to provide an outer ring, an inner ring, a cylindrical roller disposed in a double row so as to roll between the outer ring and the inner ring, and each row of the double row cylindrical rollers. Provided with a plurality of pillars that protrude in the axial direction at predetermined intervals in the circumferential direction from a ring-shaped annular part and a roller side end surface of the annular part, and are formed integrally with a synthetic resin A plurality of pocket portions configured by both side surfaces facing each other in the circumferential direction of the adjacent column portions and roller side end surfaces of the annular portions. A double-row cylindrical roller bearing held by a roller, wherein both side surfaces facing the circumferential direction of the column portion are in contact with the cylindrical roller to restrict the radial position of the cage itself. And at least a part of the range on the inner diameter side of the pitch circle diameter of the cylindrical roller, When the free end side of the column portion is bent in the diameter-expanding direction due to the force of the heart, the distance between the straight surface that does not cause the contact pressure in the bearing radial direction to act on the cylindrical roller and the roller holding portion is H1, When the maximum separation distance between the straight surfaces is H2, bearing inner diameter side ends having a separation distance H3 in a relationship of H1 <H3 <H2, and both side surfaces of the column portion The bearing inner diameter side end is achieved by a double row cylindrical roller bearing characterized by holding a lubricant.

  By adopting the above-described configuration, the bearing can be held on both side surfaces in the bearing circumferential direction by the bearing inner diameter side end portions on both sides in the bearing circumferential direction of each of the column portions, resulting in insufficient lubricant. It is possible to prevent an increase in temperature, generation of abnormal noise, a decrease in rotational performance, and the like.

  Therefore, even when rotating at high speed while being lubricated by a small amount of lubricant (such as grease or lubricating oil), excellent low noise performance can be secured, and high-speed stability and durability can be further improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A double-row roller bearing will be described as an example. However, the present invention is not limited to this, and the present invention can also be applied to a single-row roller bearing.

As shown in FIG. 1, the cylindrical roller bearing 10 includes a plurality of cylindrical rollers 13 arranged in two rows between an inner ring 11 and an outer ring 12. The plurality of cylindrical rollers 13 in each row are rotatably held by a synthetic resin cage 20 at equal intervals in the circumferential direction. The cylindrical roller bearing 10 is lubricated with a small amount of grease. However, the present invention is not limited to this, and it may be lubricated by a small amount of lubricating oil or a mixture of grease and lubricating oil.
In the first embodiment, the synthetic resin cage 20 is guided to the inner ring 11. That is, the retainer 20 rotates as the inner ring 11 rotates.

In the present embodiment, a pair of retainers 20, 20 having the same shape is incorporated in the cylindrical roller bearing 10. The cage 20 includes an annular portion 21 disposed at one end portion in the axial direction, and a plurality of pillar portions 25 extending in the axial direction at equal intervals in the circumferential direction from the side surface of the annular portion 21. ing.
In the present embodiment, the side surfaces of the pair of retainers 20 and 20 having the same shape opposite to the side where the column part 25 of the annular parts 21 and 21 is provided face each other.

  However, the form of the synthetic resin cage is not limited to this. For example, instead of facing a pair of cages, an integrally molded cage may be used. That is, you may use the holder | retainer by which the pillar part was integrally molded by the both sides | surfaces of the annular part.

  FIG. 2 is a view taken in the direction of arrow A with the cylindrical roller 13 removed in FIG. As shown in FIG. 2, the outer diameter surface 26 of the column portion 25 is disposed on the same circumference as the outer diameter surface 21 a of the annular portion 21 in a side view. In addition, a part of the inner diameter surface 27 of the column portion 25 (portion on the annular portion 21 side) is disposed on the same circumference as the inner diameter surface 21b of the annular portion 21 in a side view. The column portion 25 has a width (circumferential dimension) that decreases from the outer diameter surface 26 toward the inner diameter surface 27.

FIG. 3 shows an enlarged view of the synthetic resin cage 20 shown in FIG. In FIG. 3, hatching is omitted.
The column part 25 in this embodiment includes a root part (thick part) 25a having the same inner diameter as the inner diameter d1 of the annular part 21, and a tip part (thin part) having an inner diameter d2 larger than the inner diameter d1 of the annular part 21. ) 25b. The axial dimension of the root portion 25 a is set to 1/3 of the total length L of the column portion 25.

  The inner diameter surface of the annular portion 21 and the inner diameter surface of the root portion 25a are flush with each other. The inner diameter surface of the root portion 25a and the inner diameter surface of the tip portion 25b are smoothly connected by the curved surface R. That is, the connection portion between the inner diameter surface of the root portion 25a and the inner diameter surface of the distal end portion 25b is rounded at the radius R. The outer diameter surface of the annular portion 21, the outer diameter surface of the root portion 25a, and the outer diameter surface of the tip portion 25b are flush with each other.

In FIG. 4, the principal part of the synthetic resin cage 30 of the second embodiment of the present invention is shown. In the embodiments described below, members and the like having the same configurations and functions as those already described are denoted by the same or corresponding reference numerals in the drawings, and description thereof is simplified or omitted.
The column portion 35 in this embodiment does not have a portion having the same inner diameter as the inner diameter d1 of the annular portion 21 and has an inner diameter d2 that is larger than the inner diameter d1 of the annular portion 21 over its entire length L. The connecting portion between the inner diameter surface of the annular portion 21 and the inner diameter surface of the column portion 35 is rounded with a radius R. The outer diameter surface of the annular portion 21 and the outer diameter surface of the column portion 35 are flush with each other.

In FIG. 5, the principal part of the synthetic resin cage 40 of the third embodiment of the present invention is shown. The column part 45 in the present embodiment includes a root part (thick part) 45a having the same inner diameter as the inner diameter d1 of the annular part 21, and a tip part (thin part) having an inner diameter d2 larger than the inner diameter d1 of the annular part 21. ) 45b. The axial dimension of the root portion 45 a is set to 2/3 of the total length L of the column portion 45.
The inner diameter surface of the annular portion 21 and the inner diameter surface of the root portion 45a are flush with each other. The connecting portion between the inner diameter surface of the root portion 45a and the inner diameter surface of the tip portion 45b is rounded with a radius R. The outer diameter surface of the annular portion 21, the outer diameter surface of the root portion 45a, and the outer diameter surface of the tip portion 45b are flush with each other.

  For comparison, an example of a conventional synthetic resin cage (Comparative Example 1) is shown in FIG. A convex portion 109 is formed on the inner diameter surface of the column portion 105 of the cage 100 so as to protrude from the inner diameter surface of the annular portion 101 toward the inner peripheral side. The outer diameter surface of the annular portion 101 and the outer diameter surface of the column portion 105 are not flush with each other, and the outer diameter surface of the column portion 105 has an angle α so that the outer diameter of the column portion 105 becomes smaller toward the tip end side. Inclined.

  FIG. 7 shows a cylindrical roller bearing 50 in which a synthetic resin cage 60 according to a fourth embodiment of the present invention is incorporated. In the present embodiment, the synthetic resin cage 60 is guided to the inner ring 11. In the present embodiment, the outer diameter of the annular portion 61 of the synthetic resin cage 60 is larger than the outer diameter of the column portion 65.

  FIG. 8 is a view taken in the direction of arrow A with the cylindrical roller 13 removed in FIG. As shown in FIG. 8, a part of the outer diameter surface 66 of the column portion 65 (portion on the annular portion 61 side) is on the same circumference as the outer diameter surface 61 a of the annular portion 61 in a side view. Has been placed. Further, a part of the inner diameter surface 67 of the column portion 65 (portion on the annular portion 61 side) is arranged on the same circumference as the inner diameter surface 61b of the annular portion 61 in a side view. The column 65 has a width (circumferential dimension) that decreases from the outer diameter surface 66 toward the inner diameter surface 67.

FIG. 9 shows an enlarged view of the synthetic resin cage 60 shown in FIG. In FIG. 9, hatching is omitted.
The column part 65 in this embodiment includes a root part (thick part) 65a having the same inner diameter as the inner diameter d1 of the annular part 61, and a tip part (thin part) having an inner diameter d2 larger than the inner diameter d1 of the annular part 61. ) 65b. The axial dimension of the root portion 65 a is set to 1/3 of the total length L of the column portion 65.

  The inner diameter surface of the annular portion 61 and the inner diameter surface of the root portion 65a are flush with each other. The connecting portion between the inner diameter surface of the root portion 65a and the inner diameter surface of the tip portion 65b is rounded with a radius R1. The uniform outer diameter D <b> 2 of the column part 65 is smaller than the outer diameter D <b> 1 of the annular part 61. A connection portion between the outer diameter surface of the annular portion 61 and the outer diameter surface of the column portion 65 (base portion 65a) is rounded with a radius R2.

  In FIG. 10, the principal part of the synthetic resin holder | retainer 70 of 5th Embodiment of this invention is shown. The column portion 75 in this embodiment does not have a portion having the same inner diameter as the inner diameter d1 of the annular portion 61, and has an inner diameter d2 that is larger than the inner diameter d1 of the annular portion 61 over its entire length L. A connection portion between the inner diameter surface of the annular portion 61 and the inner diameter surface of the column portion 75 is rounded with a radius R1. The uniform outer diameter D <b> 2 of the column part 75 is smaller than the outer diameter D <b> 1 of the annular part 61. A connection portion between the outer diameter surface of the annular portion 61 and the outer diameter surface of the column portion 75 is rounded with a radius R2.

  For comparison, an example (comparative example 2) of a synthetic resin cage that departs from the present invention is shown in FIG. In the retainer 110, the column portion 115 has no portion having the same inner diameter as the inner diameter d1 of the annular portion 111, and has an inner diameter d2 that is larger than the inner diameter d1 of the annular portion 111 over the entire length L thereof. A connection portion between the inner diameter surface of the annular portion 111 and the inner diameter surface of the column portion 115 is rounded with a radius R1. The column part 115 includes a root part 115a having the same outer diameter as the outer diameter D1 of the annular part 111 and a tip part 115b having an outer diameter D2 smaller than the outer diameter D1 of the annular part 111. The axial dimension of the root portion 115 a is set to 1/3 of the total length L of the column portion 115. The connection portion between the outer diameter surface of the root portion 115a and the outer diameter surface of the tip portion 115b is rounded with a radius R2.

FIG. 12 shows still another example (Comparative Example 3) of the synthetic resin cage that departs from the present invention. The retainer 120 has a pillar portion 125 having a root portion 125a having the same inner diameter and outer diameter as the inner diameter d1 and outer diameter D1 of the annular portion 121, and an inner diameter d2 larger than the inner diameter d1 of the annular portion 121. And a tip portion 125b having an outer diameter D2 smaller than the outer diameter D1 of the annular portion 121. The axial dimension of the root portion 125 a is set to 1/3 of the total length L of the column portion 125. The inner diameter surface of the annular portion 121 and the inner diameter surface of the root portion 125a are flush with each other. The connecting portion between the inner diameter surface of the root portion 125a and the inner diameter surface of the tip end portion 125b is rounded with a radius R1. The outer diameter surface of the annular portion 121 and the outer diameter surface of the root portion 125a are flush with each other. A connection portion between the outer diameter surface of the root portion 125a and the outer diameter surface of the tip end portion 125b is rounded with a radius R2.
Stress analysis and displacement analysis were performed on the above-described cage made of synthetic resin by a finite element method (FEM).

First, with respect to the first to third embodiments and Comparative Example 1, assuming that the bearing is rotated at dmN 1.5 million, the result of analyzing the maximum stress applied to the cage by centrifugal force is shown in FIG. . Compared to Comparative Example 1, in the first embodiment (the inner wall thickness of the retainer column portion is 1/3 L), the maximum stress can be significantly reduced. Further, the second embodiment (the inner wall thickness of the cage pillar is 0) and the third embodiment (the inner diameter of the cage pillar is 2 / 3L) are also arranged in this order in the first embodiment. Next, the maximum stress could be remarkably lowered. The slope of the straight line connecting the calculated value of the first embodiment and the calculated value of the third embodiment is larger than the slope of the straight line connecting the calculated value of the first embodiment and the calculated value of the second embodiment.
From FIG. 13, it can be seen that the maximum stress increases when the inner diameter of the cage pillar portion (the length of the base portion) exceeds 2 / 3L.

Next, with respect to the first to third embodiments and comparative example 1, assuming that the bearing is rotated at dmN 1.5 million, the results of the analysis of the maximum displacement of the cage column due to centrifugal force are shown in the figure. 14 shows. Compared to Comparative Example 1, in the second embodiment (the inner wall thickness of the cage pillar portion is 0), the maximum displacement can be significantly reduced. Further, the first embodiment (the inner wall thickness of the cage pillar portion is 1/3 L) and the third embodiment (the inner wall thickness of the cage column portion is 2/3 L) are also the first in this order. Following the embodiment, the maximum displacement could be significantly reduced. The slope of the straight line connecting the calculated value of the first embodiment and the calculated value of the third embodiment is larger than the slope of the straight line connecting the calculated value of the first embodiment and the calculated value of the second embodiment.
From FIG. 14, it can be seen that the maximum displacement increases when the fleshing length (the length of the root portion) of the inner diameter of the cage column exceeds 2 / 3L.

  Next, with respect to the fourth and fifth embodiments and Comparative Examples 1 to 3, the results of the analysis of the maximum stress applied to the cage by centrifugal force on the assumption that the bearing has rotated at dmN 1.5 million are shown in FIG. As shown in FIG. In contrast to Comparative Example 1, in the fourth embodiment (the outer diameter of the cage pillar is 0 and the inner diameter is 1/3 L), the maximum stress can be significantly reduced. Further, in the fifth embodiment (the outside diameter of the cage pillar portion is 0 and the inside diameter of the cage is 0), the maximum stress can be significantly reduced following the fourth embodiment.

  Comparative Example 3 (outer diameter of the cage pillar is 1 / 3L, inner diameter is 0) and Comparative Example 4 (outer diameter of the cage is 1 / 3L, inner diameter) The maximum stress was high when the fleshing length was 1 / 3L).

  Next, with respect to the fourth and fifth embodiments and Comparative Examples 1 to 3, assuming that the bearing was rotated at dmN 1.5 million, the results of the analysis of the maximum displacement of the cage column due to centrifugal force Is shown in FIG. In contrast to Comparative Example 1, in the fifth embodiment (the outer diameter of the cage pillar portion is 0 and the inner diameter of the cage is 0), the maximum displacement can be significantly reduced. Further, in the fourth embodiment (the outside diameter of the cage pillar portion is 0 and the inside diameter of the cage is 1/3 L), the maximum displacement can be remarkably reduced following the fifth embodiment.

Next, a double-row cylindrical roller bearing (see FIG. 7) incorporating the synthetic resin cage of the fourth embodiment and a cylindrical roller bearing incorporating the synthetic resin cage of Comparative Example 1 are prepared. The temperature rises of the two were compared using the test machine. Both had an inner diameter of 95 mm and an initial radial clearance of 0 μm, and were lubricated with grease (NBU15). The results are shown in FIG.
FIG. 17 shows that according to the present invention described above, the heat generation of the bearing during high-speed rotation can be remarkably suppressed.
As shown in FIG. 18, the double-row cylindrical roller bearing 210 according to the sixth embodiment of the present invention includes an outer ring 211 having an inner ring portion formed with an outer ring raceway surface 211a, and two rows of inner ring raceway surfaces 212a on the outer diameter portion. An inner ring 212 formed with a plurality of cylinders, a plurality of cylindrical rollers 213 rotatably provided between the outer ring raceway surface 211a and the inner ring raceway surface 212a, and the cylindrical rollers 213 are rotatably held in the pocket portion. The inner ring guide type retainer 214 is arranged at a predetermined interval in the circumferential direction.

  The outer ring 211 is formed with a bent portion 211b at both ends of the inner diameter portion. The width of the outer ring raceway surface 211a excluding the bent portion 211b is equal to the width of the cylindrical roller 213 + the annular portion 214a of the retainer 214 (specifically, The width is set to be twice or more the width of (described later).

  The inner ring 212 is formed with an annular collar portion 212c at both ends, and an annular projection 212b is formed at substantially the center in the axial direction. The width of the cylindrical roller 213 is the same between the collar portion 212c and the projection 212b. Two rows of inner ring raceway surfaces 212a having a width are formed.

  The corner portions of the collar portions 212c and protrusions 212b and the inner ring raceway surface 212a are processed to have a relief portion 212d in an annular shape having an R-shaped cross section, avoiding stress concentration on the corner portions, and the corner portions of the cylindrical rollers 213. To prevent interference.

  The outer ring 211, the inner ring 212, and the cylindrical roller 213 are each formed by, for example, using a carburized bearing steel such as SCM420 or induction hardening steel such as SAE4150 to heat-treat the surface.

  The cage 214 is for holding the cylindrical rollers 213 spaced apart at a predetermined interval in the circumferential direction, and is interposed between the outer ring 211 and the inner ring 212 so as to be able to roll. For example, polyamide resin, polyphenylene sulfide resin It is formed by injection molding using a thermoplastic resin such as a polyacetal resin as a base material and adding about 10 to 30% by weight of glass fiber to improve the strength.

  The retainer 214 is integrally formed with an annular portion 214a formed in a ring shape and a plurality of cantilevered column portions 214b provided so as to protrude in the axial direction from the annular portion 214a. Yes. The side surface shape in the circumferential direction of the pillar portion 214b is a concave curved surface having a radius of curvature slightly larger than the radius of the cylindrical roller 213 on the outer diameter side, and a flat surface smoothly connecting to the concave curved surface on the inner diameter side. It has become.

  Cylindrical rollers 213 are rotatable in pocket portions formed by three sides surrounded by both side surfaces in the circumferential direction of the column portion 214b and the inner side surface 214c of the annular portion 214a. Contained and held.

The retainer 214 shown in FIG. 18 is an inner ring guide type retainer 214, and the inner diameter of the inner diameter portion of the annular portion 214a is set slightly larger than the outer diameter of the protrusion 212b of the inner ring 212. The portion is guided by the projection 212b and the position in the radial direction is restricted.
An inner diameter portion of the annular portion 214a has a straight portion 214d having a relatively short dimension t on the inner side surface 214c side, and a tapered portion 214e having a length Lβ longer than the length t of the straight portion 214d continuously from the straight portion 214d. It is a formed taper hole.
The tapered portion 214e is formed as a tapered hole having an inner diameter that gradually increases from the inner side surface 214c to the outer side surface 214f of the annular portion 214a. The optimum angle is set in the range of 1 ° to 10 ° according to the use conditions (mainly rotational speed).

The outer surface 214f of the annular portion 214a is formed with a straight portion 214g having a relatively short dimension k on the inner diameter side and continuously formed with a tapered portion 214h having a length Lα longer than the straight portion 214g on the outer diameter side. Has been.
The tapered portion 214h is inclined so that the axial dimension of the annular portion 214a gradually decreases as it moves from the inner diameter side to the outer diameter side of the annular portion 214a. The optimum angle is set in the range of 1 ° to 10 ° according to the use conditions (mainly rotational speed) of the bearing 210.

Next, a double-row cylindrical roller bearing according to a seventh embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 20, an outer ring guide type cage 224 is incorporated in a double row cylindrical roller bearing 220 of the seventh embodiment of the present invention. The retainer 224 is integrally formed with an annular portion 224a formed in a ring shape and a plurality of cantilever-like column portions 224b provided protruding from the annular portion 224a in the axial direction. .

  The side surface shape in the circumferential direction of the column portion 224b is a concave curved surface having a radius of curvature slightly larger than the radius of the cylindrical roller 213 on the outer diameter side, and a flat surface smoothly continuing to the concave curved surface on the inner diameter side. ing. In addition, cylindrical rollers 213 are respectively rotated in pocket portions formed by three sides surrounded by both sides in the circumferential direction of the column portion 224b disposed adjacently and the inner side surface 224c of the annular portion 224a. It is held freely.

The outer diameter portion of the annular portion 224a has a straight portion 224d having a relatively short dimension on the outer side surface 224f side, and a tapered portion 224e longer than the straight portion 224d, which is continuously formed from the straight portion 224d. It has become.
The outer diameter dimension of the straight portion 224d is set slightly smaller than the inner diameter dimension of the outer ring 211, and the outer diameter portion is guided by the inner diameter section of the outer ring 211 so that the radial position of the outer ring guide type retainer 224 is set. It comes to regulate.

The tapered portion 224e is formed such that the outer diameter dimension gradually decreases as it goes from the outer surface 224f to the inner surface 224c of the annular portion 224a, and the inclination angle β is determined by the use of the double row cylindrical roller bearing 220. It is set to an arbitrary angle of 1 ° to 10 ° depending on conditions.
The outer surface 224f of the annular portion 224a has a straight portion 224g having a relatively short dimension on the inner diameter side, and a tapered portion 224h longer than the straight portion 224g is formed continuously on the outer diameter side.

The tapered portion 224h is inclined so that the axial dimension of the annular portion 224a gradually decreases as it moves from the inner diameter side to the outer diameter side of the annular portion 224a. It is set in the range of 1 ° to 10 ° according to the usage conditions of the bearing 220.
In addition, since it is the same as that of the inner ring | wheel guide type | mold holder | retainer 214 of the said 6th Embodiment about another part, the same code | symbol is attached | subjected to the same part and description is abbreviate | omitted.

Next, a double-row cylindrical roller bearing according to an eighth embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 21, the double-row cylindrical roller bearing 230 according to the eighth embodiment of the present invention incorporates a roller guide type cage 234.

The cage 234 is formed by integrally forming a ring-shaped annular portion 234a and a plurality of cantilever-shaped column portions 234b protruding in the axial direction from the annular portion 234a. Has been. Cylindrical rollers 213 are rotatable in pocket portions formed by three sides surrounded by both circumferential sides of the column portion 234b and the inner side surface 234c of the annular portion 234a. The cylindrical roller 213 restricts the position of the roller guide type cage 234 in the radial direction.
The outer diameter portion of the annular portion 234a is smaller than the inner diameter of the outer ring 211, the inner diameter portion is larger than the outer diameter of the protrusion 212b of the inner ring 212, and an appropriate gap is provided between the outer ring 211 and the inner ring 212. .

On the outer surface 234f of the annular portion 234a, a straight portion 234g having a relatively short dimension is formed on the inner diameter side, and a tapered portion 234h longer than the straight portion 234g is continuously formed on the outer diameter side.
The tapered portion 234h is inclined such that the axial dimension of the annular portion 234a gradually decreases as it moves from the inner diameter side to the outer diameter side of the annular portion 234a. It is set in the range of 1 ° to 10 ° according to the use conditions of the bearing 230.
In addition, since it is the same as that of the inner ring | wheel guide type | mold holder | retainer 214 of the said 6th Embodiment about another part, the same code | symbol is attached | subjected to the same part and description is abbreviate | omitted.
The operation of the double row cylindrical roller bearing of the sixth to eighth embodiments will be described.

As shown in FIG. 19, when the double row cylindrical roller bearing 210 incorporating the synthetic resin inner ring guide type cage 214 according to the sixth embodiment is rotated at a high speed, the centrifugal force is proportional to the square of the rotational speed. A force acts on the cage 214 in the direction of arrow C (radially outward).
For this reason, the tip end of the cantilever-shaped column portion 214b is displaced in the direction of the arrow C, and accordingly, the torsional force acts on the annular portion 214a and elastically deforms. That is, the outer diameter side of the annular portion 214a is deformed in the direction of the outer surface 214f, and the inner diameter side is deformed in the direction of the inner surface 214c.

Due to the elastic deformation, the retainers 214 arranged so that the outer surfaces 214f of the annular portions 214a face each other are displaced in a direction in which the outer surfaces 214f on the outer diameter side approach each other.
However, the outer surface 214f has a tapered portion 214h that is inclined by an inclination angle α such that the axial dimension of the annular portion 214a gradually decreases as it moves from the inner diameter side to the outer diameter side of the annular portion 214a. Is formed, it is only elastically deformed until the tapered portion 214h becomes substantially parallel, and there is no interference.

  Further, the inner diameter portion of the annular portion 214a on the outer surface 214f side is displaced in the direction approaching the protrusion 212b of the inner ring 212, but the inner diameter portion is directed from the inner surface 214c of the annular portion 214a toward the outer surface 214f. Accordingly, the taper hole has an inclination angle β in which the inner diameter dimension gradually increases, so that the taper portion 214e is only elastically deformed until it becomes substantially parallel to the protrusion 212b of the inner ring 212 and does not interfere.

  Therefore, heat generation, torque fluctuation and local wear of the interference part due to the interference of the members are prevented, and deterioration of the lubricant due to heat is prevented. A double-row cylindrical roller bearing that can be continuously rotated and has a long life can be obtained.

  If the inclination angle α of the outer surface 214f and the inclination angle β of the inner diameter portion are excessively increased, it is advantageous to prevent interference, but the strength of the annular portion 214a is weakened. The optimum angle needs to be selected according to the rotational speed of the double row cylindrical roller bearing 210 used.

The present inventor has found from many tests that the inclination angles α and β are optimally set to an angle of 1 ° or more from the formation tolerance and 10 ° or less from the viewpoint of strength.
Since a straight portion 214g having a dimension k is formed on the outer side surface 214f, an axial clearance ΔH is secured between the two cages 214 even when the double-row cylindrical roller bearing 210 is rotating at low speed or stopped. Thus, the attitude of the cage 214 is stable.
Further, since the straight portion 214d having a dimension t is formed in the inner diameter portion, the cage 214 is guided by the protrusion 212b of the inner ring 212 and is positioned in the double row cylindrical roller bearing 210 in a stable posture.

The length k of the straight portion 214g is preferably set to Δh <k <Lα when the clearance between the inner diameter portion of the cage 214 and the protrusion 212b of the inner ring 212 is Δh / 2.
A value larger than Δh is a length necessary for stably managing the gap ΔH between the cages 214, and a value smaller than Lα secures more taper surfaces to achieve the effect of the present invention. This is to make the most of it.

Further, the length t of the straight portion 214d of the inner diameter portion is preferably ΔH <t <Lβ where the axial clearance between the cages 214 is ΔH.
A value larger than ΔH is a length necessary for stably managing the gap Δh / 2 between the inner ring 212 and the cage 214, and a value smaller than Lβ ensures a larger taper surface. This is to maximize the effect of the invention.

  As shown in FIG. 20, the outer ring guide type cage 224 according to the seventh embodiment of the present invention, when a double row cylindrical roller bearing 220 incorporating the cage is rotated at high speed, the cage is caused by centrifugal force. Similar to the inner ring guide type retainer 214 of the sixth embodiment, the ring portion 224a is twisted and elastically deforms 224.

However, since the outer surface 224f is formed with a tapered portion 224h so that the axial dimension of the annular portion 224a gradually decreases from the inner diameter side to the outer diameter side of the annular portion 224a, It only elastically deforms until the tapered portion 224h becomes substantially parallel, and does not interfere.
Further, the outer diameter portion of the annular portion 224a is formed in a tapered shape in which the outer diameter dimension gradually decreases as it goes from the outer surface 224f to the inner surface 224c of the annular portion 224a. It only elastically deforms until it becomes substantially parallel to the outer ring raceway surface 211a of the outer ring 211, and does not interfere.

  Therefore, similarly to the inner ring guide type retainer 214 of the sixth embodiment, heat generation and torque fluctuation are reduced, and local wear is prevented, and the life of the double row cylindrical roller bearing can be extended. .

As shown in FIG. 21, the roller guide type cage 234 according to the eighth embodiment of the present invention is rotated by a centrifugal force when a double-row cylindrical roller bearing 230 incorporating the cage is rotated at a high speed. Annular portion 234a of 234 is twisted and elastically deformed.
However, the outer surface 234f is formed with a tapered portion 234h so that the axial dimension of the annular portion 234a gradually decreases as it moves from the inner diameter side to the outer diameter side of the annular portion 234a. The taper portions 234h are only elastically deformed until they are substantially parallel to each other, and do not interfere with each other.

  Further, the outer diameter portion and the inner diameter portion of the annular portion 234a are provided with appropriate gaps from the outer ring 211 and the inner ring 212, respectively, so that they do not interfere even if elastic deformation occurs. Therefore, heat generation and torque fluctuation due to component interference can be reduced, and local wear can be prevented.

An example according to the double row cylindrical roller bearing of the sixth to eighth embodiments of the present invention described above and a comparative example to be compared with the example will be described. That is, it was performed in order to confirm the effect of the cage incorporated in the double row cylindrical roller bearing of the present invention in order to compare with Example 1, Example 2, Example 3, Example 4, and Example. The test of Comparative Example 5 will be described.
In the test, three types of inner ring guide type cages with inclination angles α and β of 0 °, 2.9 ° and 10 °, and an inclination angle α of 2.9 ° An inner ring guide type cage having an angle β of 10 ° was formed of a synthetic resin, and a double row cylindrical roller bearing formed by incorporating the cage was used as a sample.

Further, the evaluation was made based on the reached dmN value (Bitch circle diameter × rotational speed) when the double row cylindrical roller bearing was rotated, and whether or not an abnormality had occurred.
The test results are shown in Table 1.

In the tests of Examples 1 to 4 in which the outer surface has an inclination angle of 2.9 ° or 10 ° and the inner diameter portion has an inclination angle of 2.9 ° or 10 °, the dmN value ( Pitch circle diameter × rotational speed) reached 1.44 million, and no abnormality was observed.
On the other hand, in Comparative Example 5 in which the outer surface and the inner diameter portion were not provided with the inclination angle, when the dmN value was 970,000 or more, the double-row cylindrical roller bearing was abnormally hot.

Further, after the test was completed, it was disassembled and the internal condition was confirmed. As a result, significant wear was observed on the pocket side surface and the outer surface of the cage, and wear was also confirmed on the guide surface of the inner ring.
From the above test results, it was proved that the double row cylindrical roller bearing of the present invention is extremely effective against wear and heat generation.

As shown in FIG. 22, in the double row cylindrical roller bearing 331 according to the ninth embodiment of the present invention, each cylindrical roller 336 is mutually connected for each roller row arranged in two rows between the inner ring 333 and the outer ring 334. Is provided with a synthetic resin cage 338 for holding the bearing circumferential direction interval.
The synthetic resin cage 338 includes an annular portion 341 arranged coaxially on the inner end side of the cylindrical roller 336 in each roller row, and a plurality of columns protruding in the axial direction from the roller side end surface of the annular portion 341. Part 343.

  Each of the column portions 343 is a so-called cantilever shape having a free end at its tip, and as shown in FIG. 23, both side surfaces 343a and 343b in the bearing circumferential direction of each column portion 343 and the annular portion 341 are formed. The roller side end surface 341a constitutes a pocket that holds the interval between the cylindrical rollers 336 on the same roller row.

  Furthermore, in the synthetic resin cage 338 of the ninth embodiment, roller holding portions 344 that are roller-guided by the cylindrical rollers 336 of each roller row are provided on both side surfaces 343a and 343b in the bearing circumferential direction of the column portion 343. Thus, the radial position of the cage itself is regulated by contact with the cylindrical roller 336.

In addition, the outer peripheral surface 343c of each column portion 343 in the ninth embodiment is a tapered surface that gradually decreases in diameter toward the tip in the axial direction by an angle β, so that a part of the column portion 343 is reduced in weight. Therefore, the bending deformation in the diameter expansion direction due to the centrifugal force is suppressed.
Note that the synthetic resin cage 338 located on the right side in FIG. 22 shows a state in which the tip of the column part 343 is bent in the diameter-expanding direction by a centrifugal force when the inner and outer rings 333 and 334 are rotated relative to each other. A normal posture without bending during rotation is indicated by a two-dot chain line.

  In addition, a tapered surface 351 inclined at an angle α is formed on the outer diameter side on the back surface (opposite side surface of the roller-side end surface 341a) 341b of each annular portion 341 opposed between the inner and outer rings 333, 334, A flat surface 352 perpendicular to the axis is formed on the inner diameter side.

  The taper surface 351 is formed by bending the free end side of the column portion 343 in each synthetic resin cage 338 in the diameter-expanding direction by centrifugal force, so that each annular portion 341 that is abutted between the inner and outer rings 333 and 334 is formed. This is to prevent the axial friction between the outer diameter sides and the cylindrical roller 336, thereby causing unnecessary sliding friction. Further, the flat surface 352 serves as a reference surface for managing a gap between the synthetic resin cages 338 opposed to the back surface 341b to ensure an appropriate position.

  The angle α of the tapered surface 351 on the back surface 341b of the annular portion 341 and the angle β of the outer peripheral surface 343c of the column portion 343 are preferably in the range of 1 to 10 degrees. That is, a taper having an angle smaller than 1 degree is easily affected by manufacturing errors such as deformation after molding due to molding distortion and remaining burrs, and a taper having an angle larger than 10 degrees is a column or There is a possibility that the annular part may be thinned and cause insufficient strength.

  Furthermore, as shown in FIG. 23, the bearing circumferential direction both side surfaces 343a and 343b of the pillar portions 343 in the ninth embodiment have a range on the outer diameter side from the pitch circle diameter 355 where the cylindrical rollers 336 are disposed. The cylindrical roller 336 is formed on a circular arc surface 357 having a radius of 1.005 to 1.1 times the radius of the cylindrical roller 336, and the inner diameter side range from the pitch circle diameter 355 is in contact with the cylindrical roller 336 in the bearing radial direction. It is formed on the straight surface 358 that does not act.

  That is, according to the synthetic resin cage 338 having the above-described configuration, when the free end side of the column portion 343 is bent in the diameter-expanding direction due to centrifugal force, the straight formed respectively on the bearing circumferential direction side surfaces 343a and 343b. Since the surface 358 is in contact with the cylindrical roller 336, no twisting occurs between the column portion 343 and the cylindrical roller 336.

  Therefore, the double-row cylindrical roller bearing 331 according to the ninth embodiment can prevent the generation of abnormal noise and fatigue due to the twisting of the column portion 343, and the rotational performance due to a temperature rise or the like. It is also possible to suppress the decrease in noise, and to ensure excellent low noise, high speed stability, and durability.

The configuration of the bearing circumferential direction both side surfaces 343a and 343b is not limited to the configuration of the first embodiment, and various configurations can be adopted.
For example, the synthetic resin cage 348 of the double row cylindrical roller bearing according to the tenth embodiment of the present invention shown in FIG. 24 is an annular portion 351 arranged coaxially on the inner end side of the cylindrical roller 336 in each roller row. And a plurality of column parts 353 projecting in the axial direction from the roller side end face of the annular part 351.

  Each of the column portions 353 has a cantilever shape with a free end at the tip, and the same roller is formed by the bearing circumferential side surfaces 353a and 353b of each column portion 353 and the roller side end surface 351a of the annular portion 351. A pocket is formed to hold the interval between the cylindrical rollers 336 on the row.

  The both sides 353a and 353b in the bearing circumferential direction of each column portion 353 are formed on the circular arc surface 357 in the outer diameter side of the pitch circle diameter 355 where the cylindrical rollers 336 are disposed, and the pitch circle diameter 355 is formed. A range on the inner diameter side is formed on the straight surface 358 that does not apply contact pressure in the radial direction of the bearing to the cylindrical roller 336 that is in contact therewith.

  Further, in the bearing circumferential direction both side surfaces 353a and 353b of each column portion 353, the distance between the roller holding portions 354 and 354 that are mounted on the outer diameter side of the column portion 353 and guided by the rollers is H1, When the separation distance between the straight surfaces 358 and 358 is H2, and the separation distance between the bearing inner diameter side ends is H3, both side surfaces 353a and 353b in the bearing circumferential direction of each column portion 353 so as to satisfy H1 <H3 ≦ H2. A protrusion row 359 was provided at the end portion on the inner diameter side of the bearing.

  That is, a lubricant such as grease is held on the bearing circumferential side surfaces 353a and 353b by the projection rows 359 provided at the bearing inner diameter side ends of the bearing circumferential side surfaces 353a and 353b of the pillars 353. It is possible to prevent a temperature rise, abnormal noise, or a decrease in rotational performance due to a lack of lubricant.

  Therefore, even when rotating at high speed while being lubricated with a small amount of lubricant, excellent low noise performance can be secured, and high-speed stability and durability can be further improved.

  In addition, the synthetic resin cage 361 of the double-row cylindrical roller bearing according to the eleventh embodiment of the present invention shown in FIG. 25 has the bearing circumferential direction both side surfaces 362a and 362b of the column portion 362 formed by straight surfaces. The holding portion 363 has a chamfered shape.

  The synthetic resin cage 371 of the double-row cylindrical roller bearing according to the twelfth embodiment of the present invention shown in FIG. 26 is configured such that both sides 372a and 372b in the bearing circumferential direction of the column portion 372 are straight surfaces and have rollers. Only the portion 373 is an arc surface having a radius R.

  The synthetic resin cage 381 of the double-row cylindrical roller bearing according to the thirteenth embodiment of the present invention shown in FIG. 27 has a pitch at which the cylindrical rollers 336 are arranged on both side surfaces 382a and 382b in the bearing circumferential direction of the column portion 382. A range on the outer diameter side of the circle diameter is formed on the arc surface 384 having the radius R2, a range on the inner diameter side of the pitch circle diameter is formed on the straight surface 385, and the roller holding portion 383 is formed on the arc surface of the radius R. It is what. The radius R2 of the arc surface 384 is formed to be 1.005 to 1.1 times the radius of the cylindrical roller 336.

  That is, the synthetic resin cages 361, 371, and 381 of the eleventh to thirteenth embodiments also provide a space between the column portion and the cylindrical roller, similar to the synthetic resin cage 338 of the first embodiment. It is possible to prevent the occurrence of abnormal noise and the occurrence of fatigue due to the column part being not twisted.

  Furthermore, in the synthetic resin cages 371 (381) of the twelfth and thirteenth embodiments, when the chamfer radius of the roller holding portion 373 (383) is R and the outer diameter of the cylindrical roller is Da, R If the chamfer radius R is set so as to satisfy /Da=0.05 to 0.2, the contact pressure between the cylindrical roller 336 and the holding portion 373 (383) can be kept low. Since a temperature rise caused by an increase in contact pressure between the roller 336 and the holding portion 373 (383) can be avoided, a reduction in bearing performance caused by the temperature rise is suppressed, and high-speed stability and durability are improved. Improvements can be further developed.

  In addition, as a synthetic resin material for forming the synthetic resin cage according to the double-row cylindrical roller bearing of the present invention, a general engineering plastic such as a polyamide resin whose mechanical strength is improved by adding a reinforcing fiber or the like is used. For example, by adopting a high-strength synthetic resin that has a flexural modulus of 10,000 MPa or more and a specific gravity of 2 or less, and further improved mechanical strength than usual, the quality can be further improved. Improvement and performance improvement can be aimed at.

  For example, Fortron, which is a registered trademark of Polyplastics Co., Ltd., is useful as the high-strength synthetic resin. This is a structure in which a reinforcing fiber (for example, carbon fiber) is added to a PPS (abbreviation of Polyphenylene sulfide) resin having a molecular structure on a straight chain without cross-linking, if necessary. Overcoming the drawbacks of the cross-linked PPS resin, the tensile strength and bending strength are increased, and the elongation and elastic modulus are about 10 times that of the conventional cross-linked PPS resin.

  Examples of the double row cylindrical roller bearings of the ninth and tenth embodiments of the present invention described above and comparative examples to be compared with the examples will be described. That is, with respect to the double-row cylindrical roller bearings (NN3019) of Examples 5 to 7 according to the ninth and tenth embodiments and the double-row cylindrical roller bearing of Comparative Example 6, the change in the outer ring temperature with respect to the bearing rotational speed was changed. A temperature rise test was conducted, and the results are shown in FIG.

The double-row cylindrical roller bearings of Examples 5 and 6 use a polyamide resin cage of the form shown in FIGS. 23 and 24, and Example 7 has a high strength synthetic structure of the form shown in FIG. A resin cage was used. Further, the double row cylindrical roller bearing of Comparative Example 6 uses a polyamide resin cage 301 of the form shown in FIG. 28, and the entire area of the pocket surfaces 313 a and 313 b of the column portion 313 has a radius Ra of the cylindrical roller 308. A single circular arc surface having a radius of 1.005 to 1.1 times was formed.
Furthermore, the double row cylindrical roller bearings used in Examples 5 to 7 and Comparative Example 6 described above used 6.6 cc of grease (NBU15) as a lubricant and a radial gap of 0 μm.

As a result of the above test (see FIG. 29), in Comparative Example 6, intermittent abnormal noise generated from a dmN value of about 700,000 is generated, and when the rotational speed is further increased, continuous abnormal noise is generated. When the dmN value = 900,000 and the abnormal temperature rise of the outer ring, the cage broke.
On the other hand, in each of Examples 5 to 7 equipped with the synthetic resin cage of the present invention, dmN value = 1,200,000 or more (Example 5: dmN value = 1,200,000, Example 6: dmN value = No abnormal noise was generated up to 1,330,000, Example 7: dmN value = 1440,000, and the cage was not damaged in the rotation range of the test.

  Next, for the double-row cylindrical roller bearings (NN3019) of Examples 8 to 11 having the synthetic resin cages of the respective embodiments shown in FIGS. 25 to 27, the change in the outer ring temperature with respect to the bearing rotational speed is investigated. A temperature test was conducted and the results are shown in FIG.

In the double row cylindrical roller bearing of Example 8, the synthetic resin cage 361 of the embodiment shown in FIG. 25 is used, and the chamfer radius R of the roller holding portion 363 to be chamfered is 0.2 mm. Therefore, R / Da = 0.018.
For the double row cylindrical roller bearing of Example 9, the synthetic resin cage 371 of the embodiment shown in FIG. 26 was used, and R / Da = 0.09.

For the double row cylindrical roller bearings of Examples 10 and 11, the synthetic resin cage 381 of the embodiment shown in FIG. 27 was used, and R / Da = 0.05 and R / Da = 0.06, respectively.
Furthermore, the double row cylindrical roller bearings used in the above Examples 8 to 11 use 6.6 cc of grease (NBU15) as a lubricant and have a radial clearance of 0 μm.

  As a result of the above test (see FIG. 30), by setting the ratio R / Da between the radius R of the roller holding portion and the diameter Da of the cylindrical roller to 0.05 or more, the dmN value = 1 million or more at high speed rotation. The contact surface pressure with the cylindrical roller holding part can be suppressed to the extent that no abnormal noise is generated, the interference force between the synthetic resin cage and the cylindrical roller can be suppressed, and abnormal temperature rise can be prevented. It was confirmed that it could be prevented.

  However, if the R / Da is increased to 0.2 or more, the holding capacity of the cylindrical roller becomes weak due to deformation after the cage molding or manufacturing error, and the amount of movement of the synthetic resin cage increases, or the cylindrical roller There is a possibility that a bad effect of falling off the cage will occur.

  Therefore, the ratio R / Da between the radius R of the roller holding portion and the diameter Da of the cylindrical roller is preferably set in the range of 0.05 to 0.2, and if this range is set, the temperature rises. The deterioration of the bearing performance of the double row cylindrical roller bearing due to the above can be suppressed, and the improvement in high speed stability and durability can be further advanced.

  As described above, the double-row cylindrical roller bearing according to the present invention is a bearing that supports a rotating body that rotates at high speed under lubrication with a small amount of grease or lubricating oil, such as a motor-driven shaft or a main shaft of a machine tool. And is particularly suitable for double-row cylindrical roller bearings that require low heat generation in the environment.

It is sectional drawing of the cylindrical roller bearing which concerns on one Embodiment of this invention. It is A arrow directional view in FIG. It is a principal part enlarged view of 1st Embodiment. It is a principal part enlarged view of 2nd Embodiment. It is a principal part enlarged view of 3rd Embodiment. It is a figure which shows a conventional product. It is sectional drawing of the cylindrical roller bearing which concerns on one Embodiment of this invention. It is A arrow directional view in FIG. It is a principal part enlarged view of 4th Embodiment. It is a principal part enlarged view of 5th Embodiment. It is a figure which shows a comparative example. It is a figure which shows another comparative example. It is a graph explaining the effect of an Example. It is a graph explaining the effect of an Example. It is a graph explaining the effect of an Example. It is a graph explaining the effect of an Example. It is a graph explaining the effect of an Example. It is a principal part longitudinal cross-sectional view which shows the inner ring | wheel guide type cage of the double row cylindrical roller bearing which concerns on 6th Embodiment of this invention. It is a principal part longitudinal cross-sectional view which shows the state of the inner ring | wheel guide type holder | retainer elastically deformed by the centrifugal force in FIG. It is a principal part longitudinal cross-sectional view which shows the outer ring | wheel guide type cage of the double row cylindrical roller bearing which concerns on 7th Embodiment of this invention. It is a principal part longitudinal cross-sectional view which shows the roller guide type holder | retainer of the double row cylindrical roller bearing which concerns on 8th Embodiment of this invention. It is a longitudinal cross-sectional view of the double row cylindrical roller bearing according to a ninth embodiment of the present invention, It is an A direction arrow directional view of FIG. It is a partial front view of the synthetic resin cage in the double row cylindrical roller bearing according to the tenth embodiment of the present invention. It is a partial front view of the synthetic resin cage in the double row cylindrical roller bearing according to the eleventh embodiment of the present invention. It is a partial front view of the synthetic resin cage in the double row cylindrical roller bearing according to the twelfth embodiment of the present invention. It is a partial front view of the synthetic resin cage in the double row cylindrical roller bearing according to the thirteenth embodiment of the present invention. It is a figure which shows a comparative example. It is a graph which shows a temperature rising test result. It is a graph which shows a temperature rising test result. It is a principal part longitudinal cross-sectional view which shows the holder | retainer of the conventional double row cylindrical roller bearing. It is A arrow line view which shows the side surface shape of the holder | retainer in FIG. It is a principal part longitudinal cross-sectional view which shows the state of the holder | retainer elastically deformed by the centrifugal force in FIG.

Claims (2)

An outer ring, an inner ring, a cylindrical roller disposed in a double row so as to be freely rollable between the outer ring and the inner ring, and a ring-shaped annular portion provided for each row of the double row cylindrical rollers; A plurality of roller guide-type cages that are integrally formed of synthetic resin, and that are provided with a plurality of column portions that protrude in the axial direction at predetermined intervals in the circumferential direction from the roller side end surface of the annular portion. And
The cylindrical roller is a double-row cylindrical roller bearing held in a plurality of pocket portions constituted by both side surfaces facing each other in the circumferential direction of the adjacent column portion and the roller side end surface of the annular portion,
A back surface opposite to the roller side end surface of the annular portion is continuous from the flat surface formed on the inner diameter side and the flat surface, and from the inner diameter side so as to gradually reduce the axial dimension of the annular portion. Inclining in the range of 1 to 10 degrees toward the outer diameter side, having a tapered surface with a radial length longer than the radial length of the flat surface,
The back surface is opposed to the back surface of the roller guide type retainer in an adjacent row, and has a gap extending from the inner diameter side to the outer diameter side between the back surface, and centrifugal force causes the column portion When the free end side is bent in the diameter increasing direction, the gap is narrowed to allow elastic deformation of the annular portion,
The outer peripheral surface of the column part has a tapered surface that gradually decreases in diameter toward the tip in the axial direction so as to gradually reduce the radial dimension of the column part,
Both side surfaces facing the circumferential direction of the column part are a roller holding part that regulates a radial position of the cage itself by contacting the cylindrical roller, and an inner diameter side than a pitch circle diameter of the cylindrical roller And a straight surface that does not cause contact pressure in the radial direction of the bearing to act on the cylindrical roller when the free end side of the column portion is bent in the diameter-expanding direction due to centrifugal force in at least a part of the range. Double row cylindrical roller bearing.   When the separation distance between the roller holding portions is H1, and the maximum separation distance between the straight surfaces is H2, the separation distance H3 between the bearing inner diameter side ends on both side surfaces of the column portion is , H1 <H3 <H2 is set, and a lubricant is held at the bearing inner diameter side end portion.

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