JPH084773A - Solid lubricating rolling bearing - Google Patents

Abstract

PURPOSE:To maintain excellent lubricating ability over a long period of time by providing plural rolling bodies incorporated between an inner ring and an outer ring and plural almost column-shaped spacers which are incorporated between the rolling bodies adjacent to each other in the circumferential direction in a condition where an outer peripheral surface can contact with the rolling bodies and are composed of a material having selflubricating ability. CONSTITUTION:A solid lubricating rolling bearing is composed of an inner ring 1, an outer ring 2, plural rolling bodies 3 incorporated between the inner and outer rings 1 and 2, spacers 4, and a pair of shielding plates 5 installed on an inside diameter of both end parts of the outer ring 2. The rolling bodies 3 are formed by comparing and processing a solid lubricant on a steel or ceramic ball or a surface of this ball. The spacers 4 are formed of a material having self lubricating ability, for example, a sintered body containing WS2 or a PTFE type high polymer material. Thereby, when a bearing rotates, an outer peripheral surface of the spacers 4 are shaven off by contact between the rolling bodies 3 and the spacers 4, and lubricating powder is produced, and this lubricating powder forms a lubricating coating film on orbit surfaces of the inner and outer rings 1 and 2 and the rolling bodies 3, and excellent lubrication is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid lubrication bearing suitable for applications where durability and cost are important.

[0002]

2. Description of the Related Art A fluid lubricant such as grease is generally used as a lubricant for rolling bearings operating in the atmosphere. However, when operating in a vacuum, a fluid lubricant having a low vapor pressure is used in a vacuum atmosphere. A solid lubricant with a high vapor pressure is used because it evaporates into the air and cannot be used. Currently, as a solid lubricant,
Layered substances such as molybdenum disulfide, soft metals such as gold, silver and lead, and polymers such as PTFE and polyimide are widely adopted. Usually, these solid lubricants are used for inner and outer raceways and rolling elements. The surface is coated.

[0003]

By the way, when the above solid lubricant is used after being coated, it is expected that the service life will be shortened due to early wear of the lubricating coating depending on the use conditions. As a countermeasure, the cage is made of PTFE
Although a means of forming a polymeric material having self-lubricating property such as polyimide or polyimide can be considered, forming a cage having a complicated shape from a polymeric material leads to high cost. In addition, when the cage is made of a polymer material, it is often necessary to have a special dimension in order to secure its mechanical strength.

An object of the present invention is to provide a low-priced solid lubricating rolling bearing which is excellent in durability and lubricity for a long period of time.

[0005]

A solid lubricating rolling bearing according to the present invention includes an inner ring, an outer ring, a plurality of rolling elements incorporated between an inner ring and an outer ring, and rolling elements adjacent in the circumferential direction. , The outer peripheral surface of which is assembled so that it can contact the rolling elements, and
And a plurality of substantially cylindrical spacers made of a self-lubricating material.

The solid lubricated rolling bearing of the present invention has an outer peripheral surface between an inner ring, an outer ring, a plurality of rolling elements incorporated between the inner ring and the outer ring, and rolling elements adjacent in the circumferential direction. Equipped with a plurality of substantially cylindrical spacers made of a self-lubricating material, and annular shield plates attached to both ends of the inner ring or the outer ring. Is.

Further, the solid lubricating rolling bearing of the present invention is
In the above structure, the outer peripheral surface of the spacer is a concave curved surface corresponding to the surface curvature of the rolling element.

[0008]

[Operation] When the bearing rotates, contact between the rolling element and the spacer causes
Lubricating powder having self-lubricating properties is scraped off from the outer peripheral surface of the spacer, and this lubricating powder is transferred to the raceways of the inner and outer rings and the surfaces of the rolling elements to form a lubricating coating.

The spacer has a substantially columnar shape, and its outer peripheral surface is assembled in a state in which it can contact the rolling elements. Therefore, at the time of contact with the rolling element, the spacer can rotate in the direction opposite to the direction of rotation of the rolling element. There is no concern that rolling will be hindered or excessive lubricant powder will be generated. This contributes to further improving the lubricity and durability of the bearing and reducing the amount of dust generated outside the bearing. Moreover, a plurality of substantially cylindrical spacers are required for one bearing, but since they are relatively simple in shape, even if they are made of a self-lubricating material such as PTFE, they are easy to manufacture. Moreover, since it can be mass-produced, the cost is low.

Further, by attaching shield plates to both ends of the inner ring or the outer ring, both ends of the spacer can be guided by the inner surface of the shield plate, and further, dust is scattered by the shield plates to the outside of the bearing. Is suppressed.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

The solid lubricating rolling bearing of the first embodiment shown in FIGS. 1 (a) and 1 (b) has an inner ring 1, an outer ring 2, and a plurality of rolling elements 3 incorporated between the inner and outer rings 1, 2. , The spacer 4, and the pair of shield plates 5 mounted on the inner diameters of both ends of the outer ring 2.

The rolling element 3 is a ball made of steel or ceramic, or the surface of the ball is subjected to a comparative treatment with a solid lubricant. The spacer 4 is made of a self-lubricating material, for example,
Sintered body containing WS2 (for example, Miracle pillow made by Nippon Steel), polyimide (for example, SP made by DuPont)
-1, etc.) and a PTFE-based polymer material. When used in a heat-resistant environment, a sintered body containing WS2 or polyimide is used, and when used in a room temperature environment, a PTFE polymer material is preferably used. The spacer 4 is formed in a cylindrical shape as shown in FIG. 3, for example.
The spacer 4 having such a simple shape can be easily manufactured, mass-produced, and manufactured at a low cost even if it is made of the above-mentioned material having self-lubricating property. The outer diameter of the spacer 4 is slightly smaller than the diameter of the rolling element 3, and the length thereof is slightly longer than the diameter of the rolling element 3. Each spacer 4 is assembled between the rolling elements 3 that are adjacent to each other in the circumferential direction, with the outer peripheral surface thereof being in contact with the rolling elements.

The shield plate 5 is an annular metal plate, the outer peripheral edge portion of which is fitted and fixed in an annular groove 6 formed in the inner diameter of the end portion of the outer ring 2. The shield plate 5 plays a role of preventing the spacer 4 from falling out of the bearing, guiding the both ends of the spacer 4, and
It also has a role of suppressing the lubricant powder generated inside the bearing from being discharged to the outside of the bearing.

The number and arrangement relationship of the rolling elements 3 and the spacers 4 arranged between the inner and outer races 1, 2 are determined according to the usage conditions in consideration of load capacity, lubricity and the like. In the embodiment of FIG. 1, the number of rolling elements 3 and the number of spacers 4 are the same, and the two are alternately arranged. However, it is not limited to this.

When the bearing rotates, the outer peripheral surface of the spacer 4 is scraped off due to the contact between the rolling elements 3 and the spacer 4, and the lubricant powder is generated. It is transferred to the surface of the rolling element 3 to form a lubricating coating. The lubricating coating provides good lubrication of the bearing. In this way, since the spacer 4 interposed between the rolling elements 3 functions as a kind of lubricant supply source, good lubricity is maintained for a long period of time. Further, at the time of contact with the rolling elements 3, the spacer 4 can rotate in the direction opposite to the direction of rotation of the rolling elements 3, so that the sliding frictional resistance generated at the contact portions between the two has an appropriate magnitude,
There is no concern that smooth rolling of the rolling elements 3 will be hindered or that excessive lubricant powder will be generated. This improves the lubricity and durability of the bearing, and
This contributes to reducing the amount of dust generated outside the bearing. Further, since the shield plate 5 suppresses dust generation outside the bearing, the low dust generation property is extremely good.

In the second embodiment shown in FIGS. 2A and 2B, the rolling elements 3 and the spacers 4 are incorporated in a two-to-one arrangement. Since the number of rolling elements 3 is larger than that shown in FIG. 1,
It is suitable when a higher load capacity is required. Also,
In this embodiment, as shown in FIG. 4, the outer peripheral surface of the spacer 4 is a concave curved surface n. The curvature of the concave curved surface n is set according to the curvature of the rolling element 3. Since the most concave surface of the concave curved surface n contacts the rolling element 3, the axial position of the spacer 4 in the bearing is stabilized, and the contact state with the rolling element 3 is stabilized.

Next, the results of the durability test and the dusting test performed on the product of the present invention and the comparative product are shown in FIGS.
In the figure, bearing A (invention product) has the structure shown in FIG. 1 in which spacer 4 is formed of a polymer material (NTN precision resin barely FL3800) having self-lubricating property, and bearing B ( (Comparative product) is a polymer material with self-lubricating cage (NTN Precision Resin Barely FL3800)
Formed in (without shield plate), bearing C (comparative product)
Is crystalline P on the surface of rolling elements and raceways of inner and outer rings.
It is a TFE (which has a crystal structure or a molecular structure that is not subdivided, such as PTFE in a so-called sputtering treatment coating structure) and is coated (no shield plate).

The durability test (FIG. 5) was carried out by operating the bearing under a vacuum of a load of 1 kgf (thrust load), a rotation speed of 100 rpm. As is clear from FIG.
The bearing A has the same excellent durability as the bearings B and C. The test is still ongoing, but there is no particular problem in durability when any of the bearings is rotated for about 4300 h.

In the dust generation test (FIG. 6), a load of 1 kgf (thrust load), a rotation speed of 50 rpm, and a bearing of 150 in air were used.
The amount of dust generated was measured after running for hours. As is clear from FIG. 6, the amount of dust generated by the bearing B is remarkably large,
The amount of dust generated was about the same as that of bearing C, indicating extremely low dust generation. The bearing C was developed by the present applicant for the purpose of improving low dust generation (Japanese Patent Laid-Open No. 5-338).
No. 13, etc.). The remarkable low dust generation of the product of the present invention is largely due to the appropriate reduction of the sliding friction resistance at the contact portion between the outer peripheral surface of the cylindrical spacer and the rolling element and the scattering prevention effect of the lubricating powder of the shield plate. .

[0021]

According to the present invention, when the bearing is rotated, the rolling element and the spacer come into contact with each other, so that the lubricating powder having self-lubricating properties is scraped off from the outer peripheral surface of the spacer. Since a lubricating coating is formed by rolling on the raceway surface and the surface of the rolling element, good lubricity is maintained for a long time. Moreover, the spacer has a substantially columnar shape, and since the outer peripheral surface of the spacer is assembled so that it can contact the rolling element, the sliding friction resistance generated at the contact area between the two will be an appropriate amount, and the smooth rolling of the rolling element will occur. There is no concern that movement will be hindered or excessive lubricant powder will be generated. This contributes to further improving the lubricity and durability of the bearing and reducing the amount of dust generated outside the bearing. Furthermore, since the substantially cylindrical spacer has a relatively simple shape, even if it is made of a material having a self-lubricating property such as PTFE, it can be easily manufactured and mass-produced at low cost. Moreover, the spacer with a simple shape is WS
Since it is relatively easy to manufacture it from a high heat resistant material such as a 2 type metal, it is possible to provide a special purpose solid lubrication rolling bearing with excellent high temperature characteristics. Furthermore, by attaching shield plates to both ends of the inner ring or the outer ring, both ends of the spacer can be guided by the inner surface of the shield plate, and at the same time, the shield plates suppress dust scattering outside the bearing. Therefore, the low dust generation of the bearing is further improved.

[Brief description of drawings]

FIG. 1A is a front view including a partially omitted portion showing a first embodiment of the present invention, and FIG. 1B is an enlarged cross-sectional view taken along the line AA of FIG. 1A.

2A is a front view including a partially omitted portion showing a second embodiment of the present invention, and FIG. 2B is an enlarged sectional view taken along the line BB of FIG. 2A.

FIG. 3 is an enlarged perspective view of a spacer in FIG.

FIG. 4 is an enlarged perspective view of a spacer in FIG.

FIG. 5 is a diagram showing a result of a durability test.

FIG. 6 is a diagram showing a result of a dusting test.

[Explanation of symbols]

 1 inner ring 2 outer ring 3 rolling element 4 spacer 5 shield plate n concave curved surface

Claims (3)

[Claims] 1. An inner ring, an outer ring, a plurality of rolling elements incorporated between the inner ring and the outer ring, and rolling elements which are circumferentially adjacent to each other, with their outer peripheral surfaces being in contact with the rolling elements. Embedded,
A solid lubricating rolling bearing, further comprising a plurality of substantially cylindrical spacers made of a material having a self-lubricating property. 2. An inner ring, an outer ring, a plurality of rolling elements incorporated between the inner ring and the outer ring, and rolling elements that are circumferentially adjacent to each other, with their outer peripheral surfaces being in contact with the rolling elements. Embedded,
A solid lubricated rolling bearing comprising a plurality of substantially cylindrical spacers made of a self-lubricating material and annular shield plates mounted on both ends of the inner ring or the outer ring. 3. The solid lubrication rolling bearing according to claim 1, wherein the outer peripheral surface of the spacer is a concave curved surface corresponding to the surface curvature of the rolling element.