JPH106141A - Manufacture of bearing holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily remove glass fiber of a holder surface, and improve a transition of a lubricant to a rolling body by performing surface treatment by contacting a particle-shaped substance with its holder surface after a composite material strengthened by adding glass fiber to a self-lubricating material is molded in a shape of a holder. SOLUTION: A particle-shaped substance contacting with a holder 4 surface is removed from the holder 4 surface by rubbing off its glass fiber when it strikes on the exposed glass fiber. When the particle-shaped substance strikes on a solid lubricant part of the holder 4 surface, its solid lubricant part is plastically deformed so as to be push-extended. Therefore, a plastically deformed solid lubricant enters a recessed part formed after the glass fiber is removed, and fills up the recessed part. As a result, on the holder 4 surface, particularly, on a surface of a pocket hole 3, it is put in a condition where the solid lubricant exists over the whole surface, and the contact area with a rolling body increases.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing for use in a turbo pump for sending liquid hydrogen or liquid oxygen to a rocket engine or for a bearing incorporated in a special environment where it is difficult to use grease or the like in water. The present invention relates to a method for manufacturing a cage.

[0002]

2. Description of the Related Art For example, bearings used for rocket engines and the like cannot be lubricated with lubricating oil or grease because they are used at extremely low temperatures and in liquid hydrogen or liquid oxygen. Therefore, a bearing retainer made of a material having self-lubricating properties is used, and lubrication is performed by a lubricant transferred from the retainer. As the material of the cage of the bearing used in the special environment, for example, as described in Japanese Patent Publication No. 2-20854, polytetrafluoroethylene (PTFE) resin reinforced with glass fiber is used. Is done.

When the bearing in which the cage is incorporated operates, the rolling element slides into contact with the pocket hole of the cage, and the lubricant transfers from the cage to the rolling element. The lubricant is transferred to the raceway surface, and a lubricant film is formed on the raceway surface and the like, and is used for lubrication.

As described in the above publication, the production of a cage made of the above glass fiber reinforced composite material is first performed by machining the glass reinforced composite material into a circle which is the basic shape of the retainer body. After forming into a ring, pocket holes are opened by machining.

[0005] At this time, since the glass fibers may jump out of the base material in the pocket holes, the conventional manufacturing method further dissolves the glass fibers on the cage surface with a solvent such as hydrofluoric acid. By doing so, the glass fiber that has protruded from the surface of the cage is removed, thereby preventing the contact between the rolling element and the glass fiber and, at the same time, rolling the self-lubricating material (solid lubricant: PTFE) on the pocket hole surface. It is disclosed that the contact with the moving body is improved and the life of the bearing is extended.

[0006]

However, in the above-mentioned conventional method for manufacturing a bearing cage, the molded cage is subjected to hydrofluoric acid treatment, neutralization, cleaning and surface treatment. Is complicated in many steps, which is disadvantageous in cost.

On the surface of the pocket hole of the cage surface-treated by this method, a large number of recesses (small holes) are formed in portions where glass fibers are removed. That is, since a large number of recesses are formed on the surface of the pocket hole that is in sliding contact with the rolling element, the contact area between the rolling element and the solid lubricant (PTFE) is reduced by that much, and the transfer from the cage to the rolling element is performed. There is a problem that the amount of lubricant to be used is correspondingly small.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to easily remove the glass fiber on the surface of the cage and to improve the transfer of the lubricant to the rolling elements. An object of the present invention is to provide a method for manufacturing a vessel.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing a bearing cage according to the present invention comprises forming a composite material reinforced by adding glass fiber to a self-lubricating material into a shape of a cage. After that, the surface treatment is performed by bringing a particulate substance into contact with the surface of the cage.

According to the present invention, the glass fibers exposed on the surface are removed by contacting the surface of the retainer with the particulate material by means of barrel polishing, shot blasting, or the like. The self-lubricating material on the cage surface is plastically deformed and stretched in contact with the particulate matter, and fills the concave portion on the cage surface formed after removing the glass fiber.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. The production of the cage material of the present embodiment is the same as the conventional one. For example, as shown in FIG. 1, a glass fiber woven fabric is impregnated with a PTFE resin (self-lubricating material, hereinafter referred to as a solid lubricant). The wound cloth-like composite material 1 is wound around a cylindrical core 2 having a selected diameter as appropriate under a high temperature and a high pressure until the desired outer diameter is obtained, and then laminated as shown in FIG. Manufactured by removing gold 2.

Then, the cylindrical material 1 is cut into an annular shape having a predetermined width, and the inner and outer diameter surfaces are machined and the pocket holes 3 are formed by machining, as shown in FIG.
The retainer 4 is formed into a predetermined shape.

In this state, as shown in FIG. 4, which is a cross-sectional view of the essential part showing the pocket hole portion, the pocket hole 3 is opened at right angles to the winding direction of the glass fiber woven fabric. Has many glass fibers exposed. When the cage 4 in this state is used by being incorporated into a bearing as shown in FIG. 5, when the bearing operates, the glass fibers on the surface of the cage 4 are rubbed, and the rolling elements 5 (steel balls) roll. The bearing rings 6 and 7 fall on the raceway surfaces, and the raceway surfaces are damaged or the rolling elements 5 themselves are flawed, and a solid lubricating film is less likely to be formed on the raceway surfaces, thereby shortening the life of the bearing. Cause you to

On the other hand, in the present embodiment, the molded cage 4 is subjected to a surface treatment. The surface treatment is performed by bringing a particulate substance into contact with the surface of the retainer 4 by means such as barrel polishing or shot blasting.

When the particulate matter in contact with the surface of the cage 4 hits the exposed glass fiber, the glass fiber is removed from the surface of the cage 4 by scraping the glass fiber or the like. Further, when the particulate matter hits the solid lubricant portion on the surface of the retainer 4, the solid lubricant portion is plastically deformed so as to be stretched. For this reason, the solid lubricant plastically deformed enters the concave portion formed by removing the glass fiber, and fills the concave portion. As a result, the solid lubricant is present on the entire surface of the cage 4, particularly the surface of the pocket hole 3, and the contact area with the rolling elements 5 increases.

As described above, the glass fiber is removed from the surface of the cage 4, particularly the surface of the pocket hole 3, and the transfer amount of the lubricant to the rolling elements 5 can be improved. The life of the bearing used is improved.

In addition, since the surface treatment for removing the glass fiber is performed by a simple means of contacting the particulate matter, the treatment can be performed simply and inexpensively without using a chemical such as a solvent.

The surface processing by contact of the particulate matter on the surface of the cage 4 is not limited to the above barrel polishing method or the like.

[0019]

EXAMPLE When the state of the surface of the pocket hole 3 in a state where it was formed into the shape of the cage 4 by machining was observed with a scanning electron microscope, it was found that many glass fibers protruded as shown in FIG. Can be confirmed. In the photograph of FIG. 6, the rod-shaped thing is glass fiber.

Then, the cage 4 is subjected to a barrel polishing process by a centrifugal flow barrel polishing method to perform a surface treatment. The details will be described below. A predetermined abrasive (particulate matter) and water are put into the barrel tank 10 of the centrifugal flow barrel polishing machine together with the above-mentioned cage 4 after machining, and the barrel tank 10 is given a motion. That is, as shown in FIG. 8, in a state where an even number (four in FIG. 8) of barrel tubs 10 are arranged on the turret disk 11 at equal intervals along the circumferential direction.
The turret disk 11 is rotated, and the barrel tank 10 itself is rotated once per rotation of the turret in a direction opposite to the rotation of the turret disk 11.

By this movement, the mass (mixture of abrasive and water) 12 is pressed against the turning outer peripheral side of the inner wall of the barrel tank 10 by centrifugal force, and flows in the same direction as the rotation direction of the turret disk 11, thereby holding the cage. 4 is polished.

In this polishing method, it is necessary to find an appropriate condition because a strong pressing movement is generated by the centrifugal force. That is, in order to remove glass fibers without deforming the retainer 4, appropriate selection of barrel polishing conditions such as setting of centrifugal force, water exchange time for preventing heat generation by continuous operation, selection of abrasives, etc. is important.

The abrasive used (particulate matter)
As, aluminum oxide is preferable, and the particle size is
It has been confirmed that the diameter is preferably about 0.1 mm to 2 mm, and more preferably 0.3 mm to 1.5 mm.

Further, when the rotation speed of the turret disk 11 or the like is high, the retainer 4 is deformed or the dimensional accuracy is reduced. Conversely, if the number of rotations is low, the processing time will be long and the productivity will be reduced. Then, in order to secure the allowable dimensional accuracy and the predetermined productivity, the number of rotations is 20 to 20.
It has been confirmed that 0 rpm is preferable, and more preferably 50 to 150 rpm.

In this embodiment, barrel polishing was performed under the following processing conditions. Abrasive: Aluminum oxide Abrasive particle size: 0.3 to 1.5 mm Rotation speed: 60 rpm Water exchange interval: 4 to 5 hours Processing time: 12 hours The state of the pocket hole 3 after performing the above barrel polishing is a scanning type. When observed with an electron microscope, as shown in FIG. 7, it can be confirmed that many glass fibers protruding from the surface have been removed after the treatment.

Further, in order to confirm the transfer effect of the solid lubricant in the cage 4 after the above-mentioned surface treatment, evaluation was made using a sliding test machine as shown in FIG. The tester was a 3/8 inch SUS440C ball 11 fixed to the end of the shaft 10.
Is brought into contact with the retainer 4 to rotate at a high speed. Then, the ball 11 is set in the pocket hole 3 of the cage 4, and F = 1 so that the pocket hole 3 contacts the ball 11.
With a load of kgf applied, the ball 11 is
It was rotated at 0 rpm for 5 minutes.

After that, when the sliding surface of the pocket hole 3 is observed with a scanning electron microscope, as shown in FIG. 10, a solid lubricant (PTFE) is applied almost entirely to the sliding portion. It was confirmed that the ball 11 was transferred well.

For comparison, when a sliding test was performed on the pocket hole of the cage 4 not subjected to the surface treatment under the same conditions with the above-described testing machine, as shown in FIG. Projection of the glass fiber was observed, and it was confirmed that no solid lubricant was adhered to the position of the glass fiber.

Further, when the surface of the ball 11 after the test was observed with a metallurgical microscope, when the cage 4 not subjected to the surface treatment was tested, minute flaws were detected in the left-right direction. When the cage 4 subjected to the test was tested, it was also confirmed that such minute flaws were not detected.

As described above, the bearing retainer 4 which has been subjected to a simple surface treatment of bringing particulate matter into contact with the surface of the retainer 4 manufactured by machining a self-lubricating composite material reinforced with glass fiber is incorporated. In an elastic bearing, the transfer of the solid lubricant from the pocket hole 3 to the rolling element 5 is performed favorably, and the bearing life can be extended.

In addition, since a relatively large amount of processing can be performed by relatively simple means such as barrel processing, the surface of the cage 4 can be processed at low cost.

[0032]

As described above, in the method for manufacturing a bearing cage according to the present invention, the surface treatment of the cage made of a self-lubricating composite member reinforced with glass fiber can be performed by simple means and in a simple manner. There is an effect that it can be implemented with good efficiency.

Further, there is an effect that the transfer of the lubricant from the cage in the bearing incorporating the cage is improved, and the life of the bearing used in a special environment incorporating the cage is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of manufacturing a cage material according to an embodiment of the present invention.

FIG. 2 is a view showing a cage material according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a retainer according to the embodiment of the present invention.

FIG. 4 is a sectional view taken along the line AA in FIG. 3;

FIG. 5 is a view showing a bearing incorporating a cage.

FIG. 6 is a photograph showing the shape of fibers on the surface of a pocket hole before surface treatment.

FIG. 7 is a photograph showing the shape of the fiber on the surface of the pocket hole after performing the surface treatment according to the embodiment of the present invention.

FIG. 8 is an explanatory view of a centrifugal flow barrel.

FIG. 9 is a schematic view showing a sliding test machine.

FIG. 10 is a photograph showing the shape of the fiber on the surface of the pocket hole after sliding in this example.

FIG. 11 is a photograph showing a shape of a surface fiber of a pocket hole of a comparative example after sliding in the present example.

[Explanation of symbols]

 1 Composite material (Cage material) 3 Pocket hole 4 Cage

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shin Shinseki 1-5-50 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd.

Claims (1)

[Claims] 1. A method in which a composite material reinforced by adding glass fiber to a self-lubricating material is formed into a shape of a retainer, and then a surface treatment is performed by bringing a particulate substance into contact with the surface of the retainer. A method of manufacturing a bearing retainer characterized by the above-mentioned.