JPH0914272A - Manufacture of bearing, and ball bearing cage - Google Patents

Abstract

PURPOSE: To lubricate a bearing without hindering the rotation and sliding of a bearing rolling element by forming films on the bearing rolling element and/or a rolling face before filling a solid lubricant composition in the bearing, and then filling this solid lubricant composition, formed of a mixture of thermosetting resin and lubricating grease, in the bearing. CONSTITUTION: A ball bearing cage is formed of a solid lubricant composition formed of a mixture of thermosetting resin and lubricating grease, and it is desirable that the content of the lubricating grease in this solid lubricant composition is 20wt.% or less. Films are first formed on a bearing rolling element and/or a rolling face, and then the solid lubricant composition formed of the mixture of thermosetting resin and lubricating grease is filled in a bearing. After the solid lubricant composition is solidified, the bearing is heated to the temperature higher than the fusing point of a film composition so as to eliminate the film by melting. In such a ball bearing, a lubricant oozes out of the solid lubricant composition by heat and external force such as centrifugal force, and lubricating action is displayed by the lubricant oozing out of the solid lubricant composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a bearing, and more particularly to a method for manufacturing various rolling bearings such as rolling bearings and sliding bearings filled with a solid lubricant composition. The present invention further relates to a ball bearing retainer formed from a solid lubricant composition, which is used for holding rolling elements of a small diameter ball bearing used in a video tape recorder, a laser printer, etc., and the ball. The present invention relates to a ball bearing using a bearing retainer.

[0002]

2. Description of the Related Art Lubricating grease and lubricating oil are used for lubricating bearings. Japanese Unexamined Patent Publication (Kokai) No. 6-172770 discloses a solid lubricant composition comprising a metal soap type grease, a non-metal soap type organic grease, a urethane prepolymer and an aromatic polyamine type curing agent. This solid lubricant composition, when filled into the entire bearing, is in the form of grease until it solidifies, so that details such as the rolling surface of the bearing are filled, and the solid lubricant composition adheres to the surface of the bearing before solidification, There was a problem such as hindering the rotation of the rolling elements. On the other hand, ball bearings are widely used to support various rotating parts. A retainer is used to support the rolling element of the ball bearing, and the retainer rotatably holds the rolling element. This cage is made of a brass plate, a stainless plate, a carbon steel plate or the like, but a synthetic resin one is also used. The cage of such a ball bearing needs to be filled with grease or lubricating oil for lubrication. Ball bearings are also known in which cages made of synthetic resin are impregnated with lubricating oil, and the filling of grease or lubricating oil is omitted, but the amount of lubricating oil that can be impregnated is small, and the cage itself is made porous. However, there is a problem that the manufacturing process becomes complicated and the manufacturing cost increases.

[0003]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a method of manufacturing a bearing which does not have such a problem. A second object of the present invention is to provide a ball bearing cage that does not require replenishment of grease or lubricant. A third object of the present invention is to provide a ball bearing using the above ball bearing cage.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above-mentioned object, and as a result, when filling a solid lubricant composition into a bearing, the bearing was previously coated with wax or the like. The present inventors have found that the above object can be achieved by filling the bearing with the solid lubricant composition after forming the above, and have completed the present invention. According to the present invention, when a bearing is filled with a solid lubricant composition, a coating is first formed on a rolling element and / or a rolling surface of the bearing, and then a solid lubrication comprising a mixture of a thermosetting resin and a lubricating grease. The present invention provides a method for producing a bearing, which comprises filling the agent composition with the bearing.
In a preferred embodiment of the present invention, when a bearing is filled with a solid lubricant composition, a coating is first formed on a bearing rolling element and / or a raceway surface, and then a mixture of a thermosetting resin and a lubricating grease is used. A method for producing a bearing, comprising: filling a bearing with the solid lubricant composition described above, solidifying the solid lubricant composition, and then heating to a temperature not lower than the melting point of the coating composition to melt and remove the coating. Is.

The solid lubricant composition used in the present invention for filling the bearing includes the solid lubricant composition described in JP-A-6-172770, but is not limited thereto. Instead, any mixture of thermosetting resin and lubricating grease can be used. Here, the thermosetting resin means phenol / formaldehyde resin, urea resin, melamine / formaldehyde resin, epoxy resin,
Furan resin, xylene resin, silicone resin, diallyl phthalate resin and the like can be mentioned, and a solid lubricant composition comprising a mixture of these and a lubricating grease is preferable. More preferably, the content of the isocyanate group is 1 to 40% by weight.
Is a solid lubricant composition comprising a mixture of a urethane resin containing a urethane prepolymer and an aromatic polyamine-based curing agent and a lubricating grease.

Preferred specific examples of the solid lubricant composition used in the present invention are selected from (a) metal soap type grease and non-metal soap type organic grease described in JP-A-6-172770. Grease, (b) urethane prepolymer, and (c) aromatic polyamine-based curing agent. In the above lubricant composition, the total amount of component (b) and component (c) is preferably 20 to 80% by weight, more preferably 40 to 60% by weight, based on the total weight of the composition. If it is less than 20% by weight, the lubricant composition is too soft to be a solid lubricant. On the other hand, if it exceeds 80% by weight, the lubricant composition becomes too hard and becomes a state close to a resin, and the lubricant does not exude so much that poor lubrication is likely to occur.

The component (a) of the lubricant composition of the present invention is a grease selected from metal soap type grease and non-metal soap type grease, for example, lithium grease, calcium grease, aluminum grease, lithium complex grease, calcium. Complex grease, aluminum complex grease, diurea grease, triurea grease, tetraurea grease,
Examples include polyurea grease. The base oil and additives in these greases may be those used in conventional lubricating greases. In addition, for example, an antioxidant, a rust preventive, an extreme pressure additive, a solid lubricant, etc. may be added to the grease, if necessary.

The component (b) urethane prepolymer of the lubricant composition of the present invention preferably has an isocyanate group content of 1 to 10% by weight, and further has a molecular weight of
Those of 400 to 10,000 are preferable. Such urethane prepolymers include, for example, Hyprene P-820 (Mitsui Toatsu Chemical), Hyprene P-302 (Mitsui Toatsu Chemical),
Hyprene P-305 (Mitsui Toatsu Chemicals), Hyprene P
-306 (Mitsui Toatsu Chemical), Hyprene P-760 (Mitsui Toatsu Chemical), Coronate C-4080 (Japan Polyurethane), Coronate C-4090 (Japan Polyurethane), Coronate C-4095 (Japan Polyurethane),
Coronate C-4099 (Japan Polyurethane), Coronate C-4076 (Japan Polyurethane), Coronate C
-4047 (Japan Polyurethane), Coronate C-40
48 (Japan Polyurethane), ADEKA RESIN UP-302
(Asahi Denka Kogyo), Adeka Resin UP-340 (Asahi Denka Kogyo), Adeka Resin UP-848 (Asahi Denka Kogyo), Sampren SEL No.3 (Sanyo Kasei), Sampren SEL No.2
3 (Sanyo Chemical Co., Ltd.), Samprene SEL-7460 (Sanyo Chemical Co., Ltd.), and the like may be commercially available.

The component (c) aromatic polyamine-based curing agent of the lubricant composition of the present invention has an amino group content of 1
It is preferably about 20% by weight. Such aromatic polyamine-based curing agents include, for example, MC-100 (Mitsui Toatsu Chemical), MC-506 (Mitsui Toatsu Chemical), MC-5.
91 (Mitsui Toatsu Kagaku), MDA-220 (Mitsui Toatsu Kagaku), ADEKA HARDNER CA125 (Asahi Denka Kogyo) may be used. The lubricant composition of the present invention is prepared by mixing the above components (a) and (b), further mixing and defoaming the component (c), filling the bearing, and then at a temperature of room temperature to 80 ° C. for 1 to 24 hours. It solidifies when left to stand for a while. In addition, natural oils such as wool and cellulose, or synthetic fibers such as Tetron and nylon are added to the lubricating oil to form a grease, and the components (b) and (c) of the present invention are added to lubricate it. It can be used as an agent composition. The above-mentioned grease-like material is known as a sealing material, and generally 50 to 8
It contains 0% by weight of lubricating oil and about 3 to 10% by weight of fibers.

Various waxes are preferable as the coating composition which is previously formed on the rolling elements and / or the rolling surfaces of the bearing. Any type of grease may be used as long as it has a melting point lower than the dropping point of the lubricating grease contained in the solid lubricant, and specifically includes plant-based, animal-based and mineral-based natural waxes, paraffin waxes and microcrystal waxes. Petroleum wax such as rewax, montanic acid wax,
Synthetic or semi-synthetic waxes such as coal-based synthetic wax such as montanic acid derivative wax, polyethylene wax and fatty acid wax, fatty acid ester wax, fatty acid bisamide, and oxidation wax can be used. In the bearing thus formed, the lubricant oozes from the filled solid lubricant composition by an external force such as heat or centrifugal force, and the oozing lubricant exerts a lubricating action.

Next, the ball bearing cage of the present invention will be described. The cage for ball bearings of the present invention is formed from a solid lubricant composition comprising a mixture of thermosetting resin and lubricating grease. The solid lubricant composition is as described above, but the content of the lubricating grease in the solid lubricant composition is preferably 20% by weight or less, more preferably 5 to 10% by weight. If the content of the lubricating grease exceeds 20% by weight, there is a disadvantage that the strength decreases. The solid lubricant composition constituting the cage for ball bearings has the purpose of improving the mechanical strength and heat resistance of the cage,
Reinforcing fibers used as ordinary resin reinforcing fibers such as glass fibers and carbon fibers may be added. The amount of addition
About 1 to 10% by weight is suitable. In the ball bearing using the cage for ball bearings of the present invention, an external force such as heat or centrifugal force causes the lubricant to exude from the solid lubricant composition, and the exuded lubricant exerts a lubricating action. . Since the amount of the lubricant oozing out is extremely small, good lubrication is performed for a long period of time and excellent durability is exhibited. In addition, the lubricant does not scatter or leak from the ball bearing, and the seal mechanism of the ball bearing is simplified.

[0012]

[Embodiment 1] Rolling bearing (6306) was made of white kerosene and a solvent (2-propanol: distilled water: ammonia water = 90:
After washing with 9: 1), the washed solvent was removed and the bearing was dried. After cooling to room temperature, it was heated and melted to 90 ° C (WAXREX 602: Mobil Chemical Co., Ltd.)
(Manufacturing) (melting point: 81 ° C.), the bearing was quickly taken out, excess wax was removed, and the bearing was cooled to room temperature. After confirming that the wax has completely precipitated and formed a film on the surface of the bearing, a solid lubricant composition (urethane prepolymer (Hyprene P820 (manufactured by Mitsui Toatsu Kagaku)) in which lubricating grease and urethane resin are mixed 38.5%, amine-based curing agent (MC506 (Mitsui Toatsu Chemical)) 11.5
% And lithium grease 50.0%).
The bearing filled with the solid lubricant composition is allowed to stand in a constant temperature bath at 60 ° C. to solidify the solid lubricant composition, and then heated to 100 ° C. which is higher than the melting point of the wax to remove the wax, A bearing filled with the lubricant composition was manufactured.

[0013]

Example 2 As a wax, HiMic-1045
A rolling bearing filled with the solid lubricant composition was manufactured in the same manner as in Example 1 except that (Mitsui Petrochemical) (melting point 67 ° C.) was used.

Example 3 As a wax, Hoechst wax OP
A rolling bearing filled with the solid lubricant composition was manufactured in the same manner as in Example 1 except that (Hoechst) (melting point: 98 ° C.) was used.

Fourth Embodiment Similarly to the first embodiment, WAXREX602
(Manufactured by Mobil Chemical Co., Ltd.), epoxy resin (Epicoat 828 (made by Yuka Shell Epoxy) mixed with 20 parts of Epicure T (made by Yuka Shell Epoxy)) and lithium grease at 50:50 ( Rolling bearings filled with the solid lubricant composition prepared by mixing them in a weight ratio) were manufactured.

Comparative Example 1 A rolling bearing filled with a solid lubricant composition was manufactured in the same manner as in Example 1 except that no wax was used. The rotating states of the bearings manufactured in the above Examples and Comparative Examples were observed. Table 1 shows the results.

[0014]

[Table 1] ────────────────────────────────── Lubricants filled in the skin film bearing Rotational state of the bearing Example 1 WAXREX 602 Solid Lubricant Good Good Example 2 Hi-Mic-1045 Solid Lubricant Good Good Example 3 Hoechst Wax OP Solid Lubricant Good Good Example 4 Hoechst Wax OP Solid Lubricant Good Good Comparative Example 1 Solid lubricant No rotation

[0015]

Example 5 Urethane prepolymer (Hyprene AX5
96C: Mitsui Toatsu Chemical Co., Ltd.) 59 parts by weight and mineral oil-based lithium grease 10 parts by weight are mixed, and after defoaming, amine curing agent (MC-506: Mitsui Toatsu Chemical Co., Ltd.) 31 parts by weight is added and mixed. And a paste-like mixture was obtained. This mixture was poured into a mold to produce a cage for small diameter ball bearings. A ball bearing using this retainer and a ball bearing using a conventionally used retainer made of metal were rotated at 1500 rpm under non-lubricated conditions.
An endurance test was conducted under the conditions of rpm and temperature of 60 ° C. The ball bearing using the metal cage generated a large amount of abrasion powder in a few hours and caused abnormal noise, but the ball bearing using the cage of the present invention was stable for a long time (two months). there were.

The bearing manufactured by the method of the present invention can be lubricated without disturbing the rotation or sliding of the rolling elements of the bearing. The ball bearing using the cage made of the solid lubricant composition of the present invention can perform good lubrication for a long time without replenishing the lubricant. In addition, the lubricant does not scatter or leak from the ball bearings and contaminate peripheral devices.

Claims (10)

[Claims] 1. When filling a bearing with a solid lubricant composition, first, a film is formed on a bearing rolling element and / or a rolling surface,
After that, a method for producing a bearing is characterized in that the bearing is filled with a solid lubricant composition comprising a mixture of a thermosetting resin and a lubricating grease. 2. When the bearing is filled with the solid lubricant composition, first, a film is formed on the bearing rolling element and / or the rolling contact surface,
After that, the bearing is filled with a solid lubricant composition composed of a mixture of a thermosetting resin and a lubricating grease, and after the solid lubricant composition is solidified, it is heated to a temperature equal to or higher than the melting point of the coating composition to form a coating. A method for manufacturing a bearing, characterized by melting and removing. 3. The method according to claim 1 or 2, wherein the thermosetting resin is a mixture of a urethane prepolymer and an amine curing agent. 4. The lubricating grease is lithium grease and / or urea grease, according to claim 1.
The method described in the section. 5. The method according to claim 1, wherein the coating composition is a wax having a melting point lower than the dropping point of the lubricating grease. 6. A cage for ball bearings formed from a solid lubricant composition comprising a mixture of a thermosetting resin and a lubricating grease. 7. The cage for ball bearings according to claim 6, wherein the thermosetting resin is a mixture of a urethane prepolymer and an amine curing agent. 8. The cage for ball bearings according to claim 6, wherein the lubricating grease is lithium grease and / or urea grease. 9. The cage for ball bearings according to claim 6, wherein the lubricating grease is 20% by weight or less based on the total amount of the mixture of the thermosetting resin and the lubricating grease. 10. A ball bearing using the cage for ball bearings according to claim 6.