JP2010053949A - Roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance rotating performance at a low cost with a simple construction in a ball bearing using magnetic fluid as a lubricant. <P>SOLUTION: In a retainer 14 of the ball bearing 10, a magnetic portion 15 is composed by affixing a magnet in the inside surface of a pocket 14b which retains balls 13. Since the magnetic portion 15 adsorbs a magnetic fluid as the lubricant, the lubricant is smoothly sent to the rolling surface of the balls 13 and hence the rotating performance of the ball bearing 10 is enhanced. Because inner and outer rings 11, 12, etc. have normally a simple construction without additional parts other than parts of the normal ball bearing, the manufacturing cost and the like are reduced. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rolling bearing and a thrust rolling bearing enclosing magnetic fluid, and a cage used for a rolling bearing enclosing magnetic fluid.

A magnetic fluid in which magnetic fine particles such as magnetite and composite ferrite are stably dispersed in a base liquid (water, oil, etc.) using a surfactant is known.
Since this magnetic fluid has both the properties as a magnetic substance adsorbed by a magnet and the properties of a fluid having fluidity, and has a high functionality, various uses have been proposed.

  For example, since it is possible to enclose magnetic fluid in a certain space and make it unevenly distributed at a predetermined position in the space using a magnet, an attempt to use magnetic fluid as a lubricant for a rolling bearing as in Patent Document 1 is possible. It has also been made.

  Specifically, on the end face of the inner and outer rings (see FIGS. 1 to 3 of Patent Document 1), which is the outside (outside) of the bearing, on the inner diameter surface of the inner ring and on the outer diameter surface of the outer ring (Patent Document 1). 4 and FIG. 5), a permanent magnet is arranged, and the magnetic fluid as the lubricant enclosed in the space in the bearing is remotely operated by the magnetic field of the magnet, and is unevenly distributed at a position close to the rolling element. .

Thereby, since it becomes easy to supply a lubricant on the rolling surface of the rolling element, the rotation of the bearing becomes smooth and the service life thereof is extended.
JP 59-151620 A

However, in the rolling bearing of Patent Document 1, a magnet that generates a magnetic field inside the bearing is arranged outside the bearing, and the magnetic fluid and the magnet are not in direct contact, and the magnetic field is weak inside the bearing. The force that causes magnetic fluid to be unevenly distributed in the vicinity of the rolling element is weak.
Therefore, there is room for improvement in the efficiency of supplying the lubricant on the rolling surface of the rolling element.

  Further, when the magnet is fixed to the inner and outer rings via another member (see FIGS. 1 and 2 of Patent Document 1), the number of parts increases, and when the magnet is embedded in the inner and outer rings (from FIG. 3 of Patent Document 1). Since the inner and outer rings need to have a special structure in FIG. 5), in any case, it takes time and cost.

  These problems are common when a magnetic fluid is used as a lubricant for a thrust rolling bearing.

  Accordingly, an object of the present invention is to improve the rotational performance of a rolling bearing and a thrust rolling bearing using a magnetic fluid as a lubricant with a simple structure and at a low cost.

  In order to solve the above-described problems, in the rolling bearing of the present invention, magnetic fluid as a lubricant is adsorbed on at least one of the outer diameter surface, inner diameter surface, and pocket inner surface of the cage that holds the rolling element in the pocket. A configuration having possible magnetic parts was adopted.

  That is, for a rolling bearing, an inner ring having a transfer surface formed on the outer diameter surface, an outer ring arranged concentrically with the inner ring and having a transfer surface formed on the inner diameter surface thereof, and disposed between the inner ring and the outer ring. A cage having a plurality of pockets parallel to the circumferential direction and opening in the radial direction, and a plurality of rolling elements held in each pocket of the cage and capable of rolling between the opposing transfer surfaces of the inner ring and the outer ring; And a magnetic fluid as a lubricant held between the inner ring and the outer ring, and the retainer has an outer diameter surface facing the outer ring inner diameter surface and an inner diameter facing the inner ring outer diameter surface. The structure which has the magnetic part which can adsorb | suck the said magnetic fluid in at least one of the surface and the pocket inner surface was employ | adopted.

Since the magnetic part of the cage that holds the rolling element directly contacts and adsorbs the magnetic fluid inside the bearing, the force to be unevenly distributed around the rolling element is stronger and smoother than the method of Patent Document 1. Since the lubricant is fed to the rolling surface, the rotational performance is improved.
Unlike the method of Patent Document 1, no additional parts are added in addition to the normal rolling bearing parts, and the inner and outer rings also have an ordinary simple structure, so that the costs for manufacturing and the like can be suppressed.

  When the magnetic part is provided on at least one pocket opening peripheral part of the outer diameter surface, the inner diameter surface, and the pocket inner surface of the cage, it is particularly easy to supply the lubricant to the rolling surface of the rolling element.

As the magnetic part of the retainer, a permanent magnet fixed to at least one of the outer diameter surface, the inner diameter surface, and the pocket inner surface of the retainer is preferable because it is low in cost and excellent in attractive force.
Fixing the permanent magnet to the cage is preferable because a recess is provided on at least one of the outer diameter surface, the inner diameter surface, and the pocket inner surface of the cage, and it is difficult to fall off the recess.
Or it is easy to affix a permanent magnet to a holder | retainer and to fix.

If the cage except for the inner ring, the outer ring, the rolling element and the magnetic part are made of a non-magnetic material, these bearing parts do not adsorb magnetic fluid as a lubricant, and therefore the magnetic part is lubricated. Since this does not hinder the adsorption of the agent, the supply efficiency of the lubricant to the rolling elements and the bearing rotation performance are further improved.
In addition, when the inner ring or the like is a magnetic material, these are affected by the magnetic field of the magnetic part of the cage, so that the rotational torque of the entire bearing is increased. Thus, the rotational torque can be reduced.
As the nonmagnetic material constituting the cage excluding the magnetic part, a synthetic resin is preferable because it is lightweight, inexpensive, and easy to mold.

When considering the present invention for a cage alone, a cage body made of a cylindrical non-magnetic material,
A plurality of pockets open in the outer diameter surface and the inner diameter surface of the cage body in parallel in the circumferential direction inside the cage body, and at least one of the inner diameter surface, the outer diameter surface, and the pocket inner surface of the cage body. Further, it is understood that the cage has a magnetic part capable of attracting a magnetic material.

  In order to solve the above-described problems, in the thrust rolling bearing according to the present invention, a magnetic fluid as a lubricant is provided on at least one of the surface facing the bearing disc of the cage that holds the rolling element in the pocket and the inner surface of the pocket. The structure having a magnetic part capable of adsorbing is adopted.

  That is, the thrust rolling bearing has a pair of washer disks each having a transfer surface formed on the opposite surface, and a plurality of pockets arranged between the pair of washer disks and parallel to the circumferential direction and open in the axial direction. A cage, a plurality of rolling elements held in each pocket of the cage and capable of rolling between opposing transfer surfaces of the washer, and a magnetic fluid as a lubricant held between the pair of washer And the cage has a magnetic part capable of adsorbing the magnetic fluid on at least one of the facing surface and the pocket inner surface facing each track.

  As in the case of the rolling bearing described above, the magnetic part of the cage that holds the rolling elements directly adsorbs and absorbs the magnetic fluid, so that the rotational performance is improved and no separate parts are required. Since this structure is sufficient, the cost of manufacturing and the like can be suppressed.

  For the same reason as in the case of the rolling bearing described above, the magnetic part of the cage is preferably a permanent magnet fixed to at least one of the opposing surface of the cage and the inner surface of the pocket. All of the cages excluding the magnetic part are preferably made of a non-magnetic material.

  About a rolling bearing, it is configured to have a magnetic part capable of adsorbing a magnetic fluid as a lubricant on at least one of an outer diameter surface, an inner diameter surface, and an inner surface of a cage that holds the rolling element in a pocket. Rotating with a simple structure because it has a structure that has a magnetic part that can adsorb magnetic fluid as a lubricant on at least one of the inner surface of the pocket facing the bearing plate of the cage that holds the rolling element in the pocket The performance was improved.

  Embodiments of the present invention will be described below with reference to the drawings.

A ball bearing 10 according to the first embodiment shown in FIGS. 1A, 1B and 1D includes an outer ring 12 having a deep groove transfer surface 12a formed on the inner diameter surface, and a deep groove transfer surface 11a formed on the outer diameter surface. , And a plurality of balls 13 disposed between the inner and outer rings 11 and 12.
The balls 13 roll on the transfer surfaces 11 a and 12 a as the inner and outer rings 11 and 12 rotate.
These inner and outer rings 11, 12 and balls 13 are all made of a nonmagnetic material such as nonmagnetic stainless steel.

Further, a lubricant is enclosed in the ball bearing 10.
This lubricant is a magnetic fluid in which magnetic fine particles such as magnetite and composite ferrite are added to a base oil and stably dispersed using a surfactant, and has the property of adsorbing to a magnet while being a fluid. Yes.

A retainer 14 is disposed between the inner and outer rings 11 and 12, and the balls 13 are held by the retainer 14 so that the transfer surfaces 11 a and 12 a can be smoothly moved without being offset or displaced. Can be rolled to.
The cage 14 includes a cylindrical cage body 14a and a plurality of pockets 14b arranged in parallel at equal intervals in the circumferential direction of the cage body 14a.
Each pocket 14b penetrates in the radial direction of the cage main body 14a and opens at the outer diameter surface and the inner diameter surface.
The pocket 14b has a circular shape in plan view, and one ball is held in each pocket 14b.
The cage body 14a is integrally molded by injection molding a synthetic resin that is a non-magnetic material.

As shown in the figure, a magnet sheet is attached to the entire outer diameter surface and inner diameter surface of the cage main body 14a to constitute a magnetic portion 15 that can adsorb the magnetic fluid as the lubricant.
The magnet sheet is formed by sheet molding of magnetic fine particles such as magnetite dispersed in synthetic rubber and is flexible so that it does not float along the outer and inner diameter surfaces forming the curved surface of the cage body 14a. It is easy to paste.

The ball bearing 10 of the first embodiment has the above-described configuration, and the magnetic fluid as the encapsulated lubricant is adsorbed to the magnetic part 15 made of the magnet sheet of the cage body 14a, so that the lubricant is contained in the bearing. It will be unevenly distributed around the inner and outer diameter surfaces of the cage 14.
Therefore, the lubricant is efficiently supplied to the balls 13 held in the pockets 14b of the cage 14, and the rotational efficiency of the ball bearing 10 is improved.
In particular, the magnetic part 15 forms a strong magnetic field in the ball bearing and adsorbs the lubricant directly in contact with it, while the inner and outer rings 11 and 12 and the cage body 14a are non-magnetic materials and adsorb the lubricant. The lubricity and the rotational property are further improved.
Further, since the magnet sheet is simply attached to the inner and outer diameter surfaces of the cage main body 14a, the structure is simple and the manufacturing cost can be suppressed, and the cage main body 14a is made of a synthetic resin and is lightweight.

Incidentally, the magnet sheet which comprises the magnetic part 15 may be affixed on the perimeter of only the inner diameter surface or outer diameter surface of the retainer body 14a, or may be affixed to a part of the inner diameter surface and the outer diameter surface.
Further, as shown in FIG. 1 (c), a notch-shaped recess 14c may be formed in the peripheral edge portion of the pocket on the inner diameter surface and the outer diameter surface of the cage body 14a, and a magnet may be fitted into the recess 14c and fixed. .
In this way, the lubricant can be concentrated on the peripheral portion of the pocket where the lubricant is most needed.
Further, a paint containing magnetic fine particles may be applied to the cage body instead of the magnet sheet, and the method for forming the magnetic part 15 on the cage 14 is not particularly limited.

The ball bearing 10 of the second embodiment shown in FIG. 2 is different from the first embodiment in that a magnetic portion 15 is formed on the pocket inner surface of the cage body 14a, and the other configurations are the same.
The magnetic fluid as the lubricant is concentrated on the inner surface of the pocket, so that the lubricant is efficiently fed into the rolling surface (spherical surface) of the ball 13 and the rotational efficiency of the ball bearing 10 is improved.
From the first and second embodiments, it is easily understood that the magnetic portion 15 may be formed on all of the outer diameter surface, inner diameter surface, and pocket inner surface of the cage body 14a.

The double-row roller bearing 20 of the embodiment shown in FIG. 3 includes an outer ring 22 having a transfer surface 22a formed on the inner diameter surface, an inner ring 21 having a transfer surface 21a formed on the outer diameter surface, and the inner and outer rings 21, 22. A plurality of cylindrical rollers 23 disposed therebetween.
The cylindrical rollers 23 are arranged in parallel in two rows in the bearing axial direction, and each row rolls on the transfer surfaces 21a and 22a as the inner and outer rings 21 and 22 rotate. .
Further, a flange for preventing slippage is formed between both ends of the outer diameter surface of the inner ring 21 in the axial direction and the rows of the cylindrical rollers 23.
The inner and outer rings 21 and 22 and the cylindrical roller 23 are all made of a nonmagnetic material such as nonmagnetic stainless steel.
Further, the double row roller bearing 20 is filled with a magnetic fluid as a lubricant similar to the above.

Between the inner and outer rings 21, 22, a pair of cages 24 that respectively hold the cylindrical rollers 23 of each row are arranged between the rows of the cylindrical rollers 23.
The pair of cages 24 are similar in shape and are incorporated in bearings back to back, and have a cage body and a plurality of pockets 24c arranged in parallel at equal intervals in the circumferential direction of the cage body.
The cage main body formed by integrally molding synthetic resin has an annular portion 24a and pillar portions 24b extending in the axial direction from the annular portion 24a and arranged in parallel at equal intervals in the circumferential direction, and adjacent pillars. A pocket 24c is formed between the portions 24b.
Moreover, the magnetic part 25 is formed in each pocket inner surface which makes | forms the cylindrical shape of a holder body.
The configuration of the double row roller bearing 20 is as described above, and the pocket inner surface (the portion corresponding to the pocket bottom surface of the annular portion 24a and the surface facing the adjacent column portion 24b), as with the ball bearing 10 of the above embodiment. The magnetic fluid as the lubricant is adsorbed to the roller and smoothly supplied to the rolling surface of the cylindrical roller 23.

Incidentally, the magnetic portion 25 may be formed on the outer diameter surface (the top surface side of the column portion 24b) or the inner diameter surface (the back surface of the annular portion 24a) of the cage 24.
Here, the roller as the rolling element is not limited to a cylindrical roller, but may be a tapered roller or a needle roller.
Needless to say, a magnetic part may be formed in the cage similarly for the double row ball bearing.

The thrust ball bearing 30 according to the first embodiment shown in FIG. 4A is arranged between a pair of upper and lower bearing discs 31 and 32 having transfer surfaces 31a and 32a formed on opposite surfaces, and the bearing discs 31 and 32, respectively. A plurality of balls 33.
The balls 33 roll on the transfer surfaces 31a and 32a as the track wheels 31 and 32 rotate, and the track plates 31 and 32 and the balls 33 are all made of a non-magnetic material. .
The thrust ball bearing 30 is filled with a magnetic fluid as a lubricant.

A retainer 34 integrally formed by synthetic resin injection molding is disposed between the pair of washer wheels 31 and 32 to hold the balls 33 at equal intervals.
The retainer 34 has a disk-shaped retainer body 34a and a plurality of circularly viewed pockets 34b arranged in parallel at equal intervals in the circumferential direction of the retainer body 34a. Each pocket 34b is a retainer. It penetrates the main body 34a and is open on both upper and lower sides.
As shown in the figure, magnetic portions 35 are formed on both upper and lower surfaces of the cage main body 34a facing the upper and lower washer plates 31 and 32, respectively.

The configuration of the thrust ball bearing 30 of the first embodiment is as described above. Since the magnetic fluid as the lubricant is adsorbed on the upper and lower surfaces of the cage 34, the lubricant is smoothly supplied to the balls 33 in the pocket. Will be.
The magnetic part 35 may be formed on either the upper surface or the lower surface of the cage main body 34a, or may be formed only on a part of the upper and lower surfaces, for example, the pocket opening peripheral portion.

The thrust ball bearing 30 of the second embodiment shown in FIG. 4B is different from the first embodiment in that the magnetic part 35 is formed on the pocket inner surface of the cage body 34a, and the other configurations are the same. .
The lubricant is adsorbed in the pocket, and is smoothly supplied to the rolling surface of the ball 33.

The shape and structure of the cage are not limited to those exemplified in the above embodiments, and a configuration in which a magnetic part is newly formed on an existing cage can be adopted.
Further, when the inner and outer rings 11, 12, 21, 22 and the washer 31, 32, the balls 13, 33, and the roller 23 are made of a non-magnetic material as in the embodiment, the magnetic fluid as the lubricant is magnetically affected. However, these may be made of a magnetic material.

(A) of the ball bearing of the first embodiment is a vertical cross-sectional view of the main part, (b) is a cross-sectional view of the main part excluding the inner and outer rings, and (c) is another cross-sectional view of the main part excluding the inner and outer rings. Example, (d) is a perspective view of main parts of the cage of the first embodiment. (A) of the ball bearing of 2nd Embodiment is a principal part longitudinal cross-sectional view, (b) is a principal part cross-sectional view except the inner and outer ring | wheels, (c) is a principal part perspective view of the holder | retainer of 2nd Embodiment. (A) of the double row roller bearing of the embodiment is a vertical cross-sectional view of the main part, (b) is a plan view of the main part excluding the inner and outer rings. (A) is the principal part longitudinal cross-sectional view of the thrust ball bearing of 1st Embodiment, (b) is the principal part longitudinal cross-sectional view of the thrust ball bearing of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ball bearing 11 Embodiment 11 Inner ring 11a Transfer surface 12 Outer ring 12a Transfer surface 13 Ball 14 Cage 14a Cage body 14b Pocket 14c Recess 15 Magnetic part 20 Double row roller bearing 21 Embodiment 21 Inner ring 21a Transfer surface 22 Outer ring 22a Transfer surface 23 Cylindrical roller 24 Cage 24a Ring part 24b Column part 24c Pocket 25 Magnetic part 30 Thrust ball bearings 31 and 32 of the embodiment Raceway 31a and 32a Transfer surface 33 Ball 34 Cage 34a Cage body 34b Pocket 35 Magnetic part

Claims (11)

Inner rings 11, 21 having transfer surfaces 11a, 21a formed on the outer diameter surface;
Outer rings 12, 22 arranged concentrically with the inner rings 11, 21 and having transfer surfaces 12a, 22a formed on their inner diameter surfaces;
Cages 14, 24 having a plurality of pockets 14 b, 24 c that are arranged between the inner rings 11, 21 and the outer rings 12, 22 and open in the radial direction in parallel with the circumferential direction;
A plurality of rolling elements 13, 23 held in the pockets 14b, 24c of the retainer 14 and capable of rolling between the opposing transfer surfaces 11a, 21a, 12a, 22a of the inner rings 11, 21 and the outer rings 12, 22. ,
A magnetic fluid as a lubricant held between the inner rings 11 and 21 and the outer rings 12 and 22,
The retainer 14, 24 is a magnetic part capable of adsorbing the magnetic fluid to at least one of its outer diameter surface facing the outer ring inner diameter surface, its inner diameter surface facing the inner ring outer diameter surface, and its pocket inner surface. Rolling bearing with 15, 25.   2. The rolling bearing according to claim 1, wherein the magnetic portions 15 and 25 are provided on an opening peripheral edge of at least one of the outer diameter surface and the inner diameter surface and the pocket inner surface of the cages 14 and 24 at an opening peripheral portion.   3. The rolling according to claim 1, wherein the magnetic portions 15 and 25 of the cages 14 and 24 are permanent magnets fixed to at least one of an outer diameter surface and an inner diameter surface and a pocket inner surface of the cages 14 and 24. bearing. The cages 14, 24 have a recess 14c in at least one of the outer diameter surface, the inner diameter surface, and the pocket inner surface,
The rolling bearing according to claim 3, wherein the permanent magnet is fixed to the cages 14 and 24 by being fitted into the concave portion 14 c.   The rolling bearing according to claim 3, wherein the permanent magnet is fixed to the cages 14 and 24 by pasting.   6. The holders 14 and 24 excluding the inner rings 11 and 21, the outer rings 12 and 22, the rolling elements 13 and 23, and the magnetic parts 15 and 25 are each made of a non-magnetic material. Rolling bearings.   The rolling bearing according to claim 6, wherein the cages 14 and 24 excluding the magnetic parts 15 and 25 are made of synthetic resin. A cage body 14a made of a cylindrical non-magnetic material;
A plurality of pockets 14b that are parallel to the circumferential direction of the cage body 14a and open to the outer diameter surface and the inner diameter surface of the cage body 14a,
A cage for a rolling bearing having a magnetic portion 15 capable of adsorbing a magnetic substance on at least one of an inner diameter surface, an outer diameter surface, and a pocket inner surface of the cage body 14a. A pair of washer disks 31, 32 having transfer surfaces 31a, 32a formed on opposite surfaces, respectively;
A cage 34 disposed between the pair of washer plates 31 and 32 and having a plurality of pockets 34b parallel to the circumferential direction and opened in the axial direction;
A plurality of rolling elements 33 held in the respective pockets 34b of the retainer 34 and capable of rolling between the opposing transfer surfaces 31a, 32a of the track discs 31, 32;
A magnetic fluid as a lubricant held between the pair of washer plates 31 and 32, and
A thrust rolling bearing in which the retainer 34 has a magnetic portion 35 capable of adsorbing the magnetic fluid on at least one of the facing surfaces facing the respective washer plates 31 and 32 and the pocket inner surface.   The thrust rolling bearing according to claim 9, wherein the magnetic part 35 of the retainer 34 is a permanent magnet fixed to at least one of an opposing surface of the retainer 34 and an inner surface of a pocket.   The thrust rolling bearing according to claim 9 or 10, wherein any of the cages 31 and 32, the rolling elements 33, and the cage 34 excluding the magnetic portion 35 is made of a non-magnetic material.

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