JP2009092158A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate sliding caused between a rolling element of a rolling bearing and a bearing ring. <P>SOLUTION: A cylindrical roller 3 is interposed over the whole periphery in its peripheral direction between both bearing rings of an inner ring 1 and an outer ring 2. A roller-shaped separator 4 is respectively arranged one by one between its respective cylindrical rollers by contacting with the cylindrical rollers. A cavity part 5 is formed on its inside in this separator. A through-hole 8 is formed for penetrating through the inside and outside of this cavity party, and a projection part 7 is formed on both ends of this separator. This separator is guided so as not contact with any of raceway surfaces 1a and 2a of both bearing rings by fitting its projection part in a collar part 10 formed in the bearing. Since the size of a radial load applied per one piece of the cylindrical rollers 1 can be changed by changing the number of this separator, the sliding caused between the cylindrical rollers and the bearing ring can be eliminated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention mainly relates to a rolling bearing for high-speed rotation such as an aircraft engine.

As shown in FIG. 5, generally used rolling bearings are rolling elements over the entire circumference in the circumferential direction between inner and outer races (hereinafter referred to as “inner ring 1” and “outer ring 2” as necessary). 3, and each rolling element 3 is separated (separated) by a retainer 11, and the retainer 11 is a pillar portion 13 positioned between each rolling element 3 between a pair of annular portions. Is provided to support the rolling elements 3 in the pockets 12 between the pillars 3 (see, for example, FIG. 1 of Patent Document 1).
JP 2005-69282 A

  Among these rolling bearings, those used in the above-mentioned aircraft jet engines and industrial gas turbines are used under operating conditions in which the races 1 and 2 relatively rotate at high speed and a radial load hardly acts. Is done. Under such operating conditions, centrifugal force acts on the rolling element 3 that rotates at a high speed, and the radius of rotation of the rolling element 3 is increased. On the other hand, the rolling element 3 is pressed against the inner ring 1 side by the radial load. Is small. For this reason, the track radius of the rolling element 3 remains enlarged, and the contact between the rolling element 3 and the inner ring 1 tends to be insufficient.

  If this contact is insufficient, when the inner ring 1 side is the rotation side, a so-called skidding phenomenon in which relative slip occurs between the rolling elements 3 and the inner ring 1 is likely to occur. When this skidding phenomenon occurs, there is a risk that a sliding noise due to the above-mentioned slip may be generated, or the rolling elements 3 and the inner ring 1 may be seized by heat generated during the above-mentioned slip.

  As described above, this skidding phenomenon occurs when the contact between the rolling element 3 and the inner ring 1 is weakened and slipping occurs. For this reason, for example, as shown in FIG. 6, by reducing the total number of rolling elements 3 and increasing the radial load applied to each rolling element 3, the contact between the rolling elements 3 and the inner ring 1 is increased. Technology to strengthen contact is being considered.

  However, if the total number of rolling elements 3 is reduced, the length of the pillar portion 13 of the cage 11 in the rotation direction of the raceway is increased (see FIGS. 5 and 6). Since a strong hoop stress (stress in the annular direction of the annular cage 11) due to the rotation acts on the annular portion between the column 13 and the column portion 13, the annular portion cannot withstand this hoop stress. There is a risk of breaking.

  This invention makes it a subject to eliminate the slip which arises between the rolling element of a rolling bearing, and a bearing ring, preventing the fracture | rupture of the said holder | retainer.

In order to solve the above-described problems, the present invention isolates each rolling element with a roller-shaped separator consisting only of the pillar portion instead of the cage, and rotates the separator in contact with the rolling element. It was.
In this way, since all the rolling elements rotate via the separator, the contact between the rolling elements and the inner ring is insufficient when the inner ring side is the rotating side when the rotation is performed at a high speed. However, the rolling elements continue to rotate. For this reason, relative slip does not occur between the rolling elements and the inner ring, and no skidding phenomenon occurs. Moreover, since the said annular part does not exist, the fracture | rupture resulting from the said hoop stress cannot arise.

  As a configuration of the present invention, in the rolling bearing in which a rolling element is interposed between inner and outer races over the entire circumference in the circumferential direction, and a roller-shaped separator is provided between the rolling elements, the separator is the above-mentioned While rotating in contact with the rolling element, at least one of the raceways of the inner and outer races can be made non-contact.

  Since this separator does not contact at least one of the raceways of the inner and outer races (the diameter of the separator is smaller than the diameter of the rolling element), a radial load is applied between the inner and outer races via this separator. Not transmitted. That is, the radial load is applied only to the rolling elements, and the radial load applied to each rolling element can be freely changed by changing the number of separators (that is, the interval between the rolling elements).

  Specifically, by increasing the number of separators, etc., and widening the spacing between the rolling elements, the number of rolling elements that can be accommodated between the inner and outer races is reduced. The applied radial load increases. If it does so, since sufficient contact can be ensured between the said rolling element and an inner ring | wheel in the case of rotation of this rolling element, the slip between both can be prevented.

  The separator is brought into contact with the raceway surface on the outer ring side by a centrifugal force at the time of rotation, and stably maintains a contact state with the rolling element. For this reason, rotation is reliably transmitted between the separator and the rolling element, and it is prevented that problems such as vibration occur due to separation or contact between the two during rotation.

  Since the rotation direction of the separator is opposite to the rotation direction of the rolling element in contact with the separator, a relative slip occurs between the separator and the raceway surface on the outer ring side. When there is a possibility that the heat generated by the relative slip may be a problem, for example, a protrusion is provided at the rotation center of the separator, and a guide groove or a flange for guiding the protrusion is provided. It is possible to adopt a configuration that does not contact the side raceway surface.

  This roller-shaped separator can be widely used as long as it has a circular cross section such as a spherical shape as well as a cylindrical shape and a conical shape.

  Further, in the above configuration, when an odd number of separators are provided between the rolling elements, and the separators are provided on both sides of the separators, they are in contact with the separators on both sides without contacting the rolling elements. It can also be rotated.

  All the rolling elements always rotate in the same direction (forward rotation) with the relative rotation of the inner and outer races. Along with the rotation of the rolling element, the separator disposed adjacent thereto also receives a rotational force from the rolling element and relatively rotates (reversely rotates).

For example, when the separators are arranged one by one between the rolling elements, "...-rolling element (forward rotation)-separator (reverse rotation)-rolling element (forward rotation)-..." Thus, the rotation of the rolling element is always positive.
On the other hand, when two separators are arranged between the rolling elements, "...- rolling element (forward rotation)-separator (reverse rotation)-separator (forward rotation)-rolling element (reverse rotation) ) -... ", and the contradiction arises that the rolling element rotates backward. In this case, friction occurs between the rolling element and the raceway, or between the rolling element and the separator adjacent to the rolling element.
For this reason, in order for the rolling elements to always rotate forward, it is necessary to use an odd number of separators disposed between the rolling elements.

  In order to prevent vibration of the bearing during the rotation, the number of separators disposed between the rolling elements is preferably the same, but a different number of separators are provided between the rolling elements. May be arranged.

Further, a cavity having a through hole leading to the surface of the separator may be formed, and the cavity may be filled with a lubricant that lubricates the rolling elements.
The lubricant stored in the hollow portion gradually flows out from the through hole and is supplied to the raceway surface of the raceway so that friction is generated between the raceway surface and the rolling surface of the rolling element. To prevent.

In particular, when the rolling bearing is used for an application requiring high reliability such as for an aircraft jet engine, for example, even when the supply of lubricant is stopped due to a failure of the lubricant supply system. In order to prevent the rolling bearing from seizing and stopping, it is necessary to maintain the lubrication state for as long as possible.
As described above, when the lubricant is normally supplied, the failure is caused by filling the cavity with the lubricant and supplying the lubricant to the rolling elements when the supply is stopped. It is possible to delay the time after the occurrence of seizure until the seizure occurs. As a result, a time lag is given to consider measures against the failure.

  Known lubricants such as lubricating oil and grease can be widely applied as the lubricant filled in the cavity, and for example, a solid lubricant that can contain the lubricating oil and grease inside can be employed.

  As an example of this solid lubricant, there is one in which polyethylene resin particles are expanded by heating and molded and solidified with the lubricating oil, grease, etc. included in the particles. When centrifugal force accompanying rotation of the bearing or heat generated by friction acts on the solid lubricant, the lubricating oil or the like oozes out little by little to lubricate the rolling elements.

Instead of forming the cavity in the separator as described above, or while forming the separator, the separator is made of a material that can be impregnated with a lubricant, the separator is impregnated with the lubricant, The rolling element can be lubricated by exuding the impregnated lubricant.
As an example of the material, the solid lubricant can be employed.
Since the separator is in direct contact with the rolling surface of the rolling element, the lubricant impregnated on the surface of the separator efficiently adheres to the rolling surface. For this reason, seizure between the raceway and the rolling element is prevented.

  According to this invention, the slip which arises between the rolling element of a rolling bearing and a bearing ring can be eliminated. For this reason, the wear of the bearing ring and the rolling element due to the slip can be reduced, and the rolling bearing can be smoothly rotated.

  An embodiment of the present invention will be described with reference to FIGS.

  In the rolling bearing according to the present invention, as shown in FIG. 1, cylindrical rollers 3 are interposed between the race rings 1 and 2 of the inner ring 1 and the outer ring 2 and the circumference rings 1 and 2 over the entire circumference. One separator 4 is provided between the cylindrical rollers 3.

  In this rolling bearing, when the outer ring 2 rotates clockwise relative to the inner ring 1, the cylindrical roller 3 rotates clockwise while revolving around the inner ring 1, and the separator 4 rotates around the inner ring 1 in a clockwise direction. While revolving around, it rotates counterclockwise (see the arrows in the figure).

  The separator 4 will be described with reference to FIG. 2. The separator 4 has a cylindrical shape, and a cavity 5 filled with a lubricant is formed in the separator 4. At one end of the separator 4, a hole 6 for inserting a jig for inner casing when forming the cavity 5 is formed, and a projection 7 is formed at both ends. Further, a through hole 8 that penetrates to the cavity 5 is formed on the side surface of the separator 4.

  The separator 4 has a protrusion 7 fitted into an annular flange 10 formed on a protrusion 9 provided to protrude from the outer ring 2 in the inner diameter direction of the rolling bearing. The flange portion 10 prevents the separator 4 from directly contacting the outer ring raceway surface 2a. For this reason, it is prevented that relative slip occurs between the separator 4 and the outer ring raceway surface 2a.

  Further, as described above, the cylindrical roller 3 and the separator 4 rotate while always in contact with each other, so that the cylindrical roller 3 and the separator 4 do not shake in the rotation direction.

  In the configuration of the rolling bearing shown in FIG. 1, eight cylindrical rollers 3 are interposed between the inner and outer races 1 and 2 in consideration of the lower half of the bearing omitted in the drawing. In this configuration, since the radial load is small, the contact between the inner ring raceway surface 1a and the cylindrical roller 3 becomes insufficient when the cylindrical roller 3 rotates, and a skidding phenomenon may occur.

  In this case, as shown in FIG. 3, the number of separators 4 is increased, and the number of cylindrical rollers 3 interposed between the inner and outer races 1 and 2 is reduced (in FIG. 4 including half). By doing so, the radial load applied to each cylindrical roller 3 is increased (theoretically doubled), the inner ring raceway surface 1a and the cylindrical roller 3 are sufficiently brought into contact with each other, and the skidding phenomenon is caused. It can be resolved.

  The number of separators 4 provided between the cylindrical rollers 3 can be arbitrarily changed in an odd number range in accordance with the purpose of use of the bearing and the load capacity.

When the separator 4 is made of a material that can be impregnated with a lubricant, and when a film having solid lubricity such as a fluororesin or a carbon material is formed on the surface of the separator 4, a cylinder is formed on the surface of the separator 4. Since lubricity between the roller 3 and the separator 4 can be imparted, as shown in FIG. 4, a solid separator 4 in which the cavity 5 is not formed can be obtained.
Further, even when the lubricant supply function at the time of failure of the lubricant supply system described above is not provided to the separator 4, the configuration of the separator 4 as shown in FIG.

  In addition to the cylindrical shape, the separator 4 may have a shape corresponding to a rolling element employed in a general rolling bearing, such as a ball shape or a cone shape.

  In addition, when the separator 4 is made of a material that can be impregnated with a lubricant, when the film having a solid lubricating property such as a fluorine resin or a carbon material is formed on the surface of the separator 4, the separator 4 is not necessarily provided. It is not necessary to have a rolling element shape that can rotate. This is because even if the separator 4 does not rotate, smooth rolling of the rolling element 3 can be ensured by the lubricant exuding from the separator 4 or the surface lubricity of the separator 4 itself.

Front partial sectional view of a rolling bearing according to an embodiment of the present invention A perspective sectional view of a separator used in the same embodiment Front view of rolling bearing in another embodiment Front partial sectional view of a rolling bearing according to another embodiment Front view of rolling bearing according to an embodiment of the prior art Front view of a rolling bearing according to another embodiment of the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 1a Inner ring raceway surface 2 Outer ring 2a Outer ring raceway surface 3 Cylindrical roller (rolling element)
4 Separator 5 Cavity 6 Hole 7 Protrusion 8 Through Hole 9 Protrusion 10 Gutter 11 Retainer 12 Pocket 13 Pillar Part a Lubricant Flow

Claims (4)

Rolling elements (3) are interposed between the inner and outer race rings (1, 2) over the entire circumference in the circumferential direction, and roller-shaped separators (4) are provided between the respective rolling elements (3). In bearings,
The separator (4) is rotated in contact with the rolling element (3), and at least one of the raceway surfaces (1a, 2a) of the inner and outer races (1, 2) is not contacted. Rolling bearing.   When an odd number of separators (4) are provided between the rolling elements (3) and the separators (4) are provided on both sides of the separators (4), they contact the rolling elements (3). 2. The rolling bearing according to claim 1, wherein the rolling bearing is rotated in contact with the separators (4) on both sides.   A cavity (5) having a through hole (8) communicating with the surface of the separator (4) is formed, and the lubricant (a) of the rolling element (3) is filled in the cavity (5). The rolling bearing according to 1 or 2.   4. The rolling element (3) according to claim 1, wherein the rolling element (3) is lubricated by impregnating the separator (4) with a lubricant and causing the impregnated lubricant (a) to ooze out. Rolling bearings as described in

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