JPH0246317A - Retainer for high temperature rolling bearing - Google Patents

Abstract

PURPOSE:To stabilize rolling contact and to prevent cracking and so on during assembly, by having a rolling contact portion of a cylindrical retainer with a rolling element made of a graphite compound material, and by having a peripheral portion of a circular hole made of a graphite compound material of high intensity. CONSTITUTION:A rolling contact portion of a cylindrical retainer A and a rolling element 6 is formed with a graphite compound material C2 that is excellent in a sliding characteristic. On the other hand, A peripheral portion of a circular hole B of the cylindrical retainer A is formed with a high intensity graphite compound material C1. In its use in a high temperature region, a graphite membrane is formed on the surface of the rolling element 6 from the cylindrical retainer A, and as the rolling element 6 is guided, graphite membrane is formed in movement on raceway surfaces of outer rings 4, 5, and the stable rolling contact is thus obtained. Also, when the rolling element 6 is fitted into the circular hole B, cracking or generation of breakage at the portion can be prevented.

Description

Detailed Description of the Invention "Industrial Application Field J The present invention relates to a cage that fits and holds rolling elements that are guided by rolling between the raceway surfaces of an inner ring and an outer ring, and is particularly suitable for high-temperature radial or thrust rolling. It is installed between the bearing cage.

"Prior Art" In recent years, as a result of pursuing higher speed, lighter weight, and higher efficiency, the operating temperature of machines has become higher, and as a result, the demand for high-temperature rolling bearings has increased.

In rolling bearings used in high temperature ranges (over 300°C), fluid lubricants such as lubricating oil or grease cannot be used between the rolling contact surfaces, so solid materials such as graphite or molybdenum disulfide are usually used. Lubricants are used.

This solid lubricant does not have fluidity or wettability like a fluid lubricant, so when it is used, it is not possible to apply or fill between the rolling contact surfaces.

Therefore, when using a solid lubricant, a retainer that fits and holds the rolling elements that are guided by rolling between the raceway surfaces of the inner and outer rings is formed using the solid lubricant, and is held on the surface of the rolling elements during transfer. The solid lubricant is transferred from the machine and a solid lubricant film is formed on the surface of the rolling element, and furthermore, the solid lubricant film is formed on the raceway surfaces of the inner and outer rings due to rolling contact with the rolling element. A method has been adopted in which lubrication is performed using a solid lubricant film formed between the rolling contact surfaces.

However, graphite has conventionally been used in cages for high-temperature rolling bearings.

``Problems to be solved by the invention'' However, the cage made of graphite has a relatively high temperature (2
Although it exhibits stable lubricity in the temperature range (00 to 300°C), it suffers from severe oxidative wear when used in higher temperature ranges, and has shortcomings in mechanical strength. When fitting together, there is a problem that cracks and damage often occur.

The present inventors focused on the lubricity of graphite in high-temperature regions, and as a result of further investigating the friction mechanism of a rolling bearing using the conventional cage made of graphite as described above, the inventors found that It was discovered that there is a directionality in the rolling contact direction of the supported rolling elements.

That is, it has been found that the direction of rolling contact between the cage hole and the rolling element is the circumferential edge of the circular hole in which the rolling element is fitted and held in both radial and thrust bearings.

Based on this knowledge, the present invention has developed a high-temperature rolling bearing that is mainly made of graphite, which has excellent sliding properties in the rolling contact direction, excellent mechanical strength in other regions, and extremely low oxidative wear even in high-temperature regions. The purpose is to obtain a vessel.

"Means for Solving Problems" In order to achieve the above-mentioned object, the present invention adopts the following technical means (configuration).

That is, the first configuration of the present invention is a cylindrical cage that fits and holds rolling elements that are guided by rolling between raceway surfaces of an inner ring and an outer ring, and the rolling elements are mounted on the circumferential surface of the cage. A plurality of circular holes are formed to fit and hold each other, and the area from both ends of the retainer to the periphery of the circular holes in the width direction is made of a high-density resin mainly composed of graphite and containing boron carbide dispersed in the graphite. It is made of a strong graphite-based composite, and the other regions are made of a graphite-based composite with excellent sliding properties, mainly composed of graphite and containing metal borides or metal borides and boron carbide dispersed in the graphite. The second structure is a cylindrical cage that fits and holds the rolling elements that are rolled and guided between the raceway surfaces of the inner ring and the outer ring. A plurality of circular holes for fitting and holding the rolling elements are formed on the circumferential surface of the cage and communicate with a groove opened at one end surface of the cage, and the cage is The area from the end face opposite to the groove to the periphery of the circular hole in the width direction is formed of a high-strength graphite-based composite mainly composed of graphite and containing boron carbide dispersed in the graphite, and the other area A high-temperature rolling bearing, characterized in that it is integrally formed of a graphite-based composite with excellent sliding properties, mainly consisting of graphite and containing a metal boride or a metal boride and boron carbide dispersed in the graphite. The third structure is a cylindrical cage that fits and holds rolling elements that are rolled and guided between raceway surfaces of an inner ring and an outer ring, and the end surface of the cage has a circumferential direction. A plurality of circular holes are formed in the cage to fit and hold the rolling elements, and the area from the inner circumferential edge and the outer circumferential edge to the circumferential edges of the circular holes is mainly composed of graphite, and the graphite contains carbonized carbon. It is made of a high-strength graphite-based composite that contains boron dispersed, and the other regions are mainly graphite, and the graphite contains metal borides or metal borides and boron carbide dispersed therein, resulting in excellent sliding properties. This is a high-temperature rolling bearing cage characterized by being integrally formed of a graphite-based composite.

In the first, second, and third configurations described above, the metal boride forming the graphite-based composite with excellent sliding properties includes:
Borides of metals of groups rVa, Va, and Via of the periodic table of elements, including titanium boride (TiB), titanium diboride (TiB2), and zirconium diboride (Zr).
B2), hafnium diboride (HfBi), vanadium diboride (VB2), niobium diboride (Nb8λ)
), tantalum diboride (TaBz), chromium boride (
Cry), chromium diboride (Crew), molybdenum diboride (MoB2), tungsten boride (WB)
, tungsten diboride (WBx), etc., and these may be used alone or in combination of two or more.

In addition to the metal borides mentioned above, in the pressurized/heated sintering process described later, elemental periodic compounds that react with boron carbide to form metal borides in the presence of boron carbide can also be used. Groups ■a, Va, and VI of the Table of Laws
Carbides of group A metals, such as titanium carbide (TiC),
Carbide, zirconium (ZrC), hafnium carbide ()I
fC), vanadium carbide (VC), niobium carbide (NbC)
), tantalum carbide (TaC), chromium carbide (Cr3C2
), molybdenum carbide (MoC), tungsten carbide (VC), etc. The cage having the above-mentioned structure is mainly composed of calcined pitch coke, and contains boron carbide or boron carbide cord and metal boride. and/or a predetermined amount of metal carbide is blended and sintered under pressure and heat (hot press) to convert the coke into graphite by the graphitization and sintering promoting effects of the boron carbide and/or metal boride. It is formed from a graphite-based composite in which boron carbide and/or metal borides are dispersed and contained in the graphitized graphite.

Each manufacturing method will be explained below.

<Preparation of raw material powder> l) A predetermined amount of boron carbide powder (B4C) with an average particle size of 1.5 μm is blended into calcined pitch coke powder with a particle size of 150 μm or less, and mixed to form the coke powder and boron carbide powder. Obtain a uniform mixed powder of (hereinafter referred to as "mixed powder ■")
.

2) Blend and mix a predetermined amount of one or more metal boride powders of Group IVa, Group Va, and Group IVa with an average particle size of 7 μm to calcined pitch coke powder with a particle size of 150 μm or less. A uniform mixed powder of the coke powder and metal boride powder is obtained (hereinafter referred to as "mixed powder (2)").

3) To calcined pitch coke powder with a grain size of 150 μI or less, add a predetermined amount of one or more of metal boride powders of Group IVa, Group Va, and Group ■a with an average grain size of 7 μm and boron carbide powder. A predetermined amount is blended and mixed to obtain a uniform mixed powder of the coke powder, metal boride powder, and boron carbide powder (hereinafter referred to as "mixed powder (2)").

4) Adding a predetermined amount of one or more of metal boride powders of Group IVa, Group Va, and Group IVa with an average particle size of 7 μm to calcined pitch coke powder with a particle size of 150 μm or less and the metal carbide. The same amount or more of boron carbide powder as the powder is blended and mixed to obtain a uniform mixed powder of the coke powder, metal carbide powder, and boron carbide powder (hereinafter referred to as "mixed powder (2)").

Manufacturing method〉 (a) A method for manufacturing a cage having the first configuration.

(First step) A graphite mold 2 having a hollow cylindrical portion l on the inner surface and a core rod 8 in the center is prepared, and the above mixed powder (2) is evenly filled to a predetermined height in the hollow cylindrical portion l of the graphite mold 2. Press powder (4th step)
In the figure, symbol ■).

(Second step) On top of the compacted mixed powder (1), any one of the above-mentioned mixed powder (2), mixed powder (2), or mixed powder (2) is uniformly filled to a predetermined height and compacted (see Fig. 4). , code ■ or ■ or ■).

(Third step) On top of the compacted mixed powder ■ or mixed powder ■ or mixed powder ■, further mixed powder ■ is uniformly filled and compacted (symbol ■ in Fig. 4). A three-layer green compact consisting of mixed powder (1) - mixed powder (2) (or mixed powder (2) or mixed powder (3)) - mixed powder (3) is formed in the hollow cylindrical portion.

(Fourth step) The three-layer green compact is heated to 150 kg/cm or more under a pressure of 100 kg/cm or more, preferably 150 to 300 kg/cm.
Pressure and heat sintering (hot pressing) is performed at a temperature of 0° C. or higher, preferably 1800 to 2500° C., to obtain a sintered cylindrical body.

In this pressurized/heated sintering process, the calcined pitch coke has the effect of promoting graphitization and sintering of boron carbide and/or metal boride (mixed powder ■, mixed powder ■, mixed powder ■) blended into the coke. graphitized by the action,
The sintered cylindrical body is a high-strength graphite-based composite in which a predetermined width region in the width direction from both ends is mainly composed of graphite and boron carbide is dispersed in the graphite, and the other region is mainly composed of graphite and contains boron carbide dispersed in the graphite. It is formed of a graphite-based composite with excellent sliding properties, consisting mainly of metal boride or graphite in graphite, with metal boride and boron carbide dispersed in the graphite.

In addition, in the pressurized and heated sintering process, the mixed powder (■) reacts with the boron carbide in the presence of boron carbide to form a metal boride, and this metal boride is dispersed and contained in the graphite. to form a graphite-based composite with excellent sliding properties.

(Fifth step) The central part of the outer circumferential surface of the sintered cylindrical body obtained in this way, that is, the sliding property is mainly composed of graphite and metal boride or metal boride and boron carbide are dispersed in the graphite. A plurality of circular holes are formed regularly in the circumferential direction by machining the excellent graphite-based composite part.

In this manner, through the first to fifth steps, a cylindrical cage A having a plurality of circular holes B made of a graphite composite shown in FIGS. 1 and 2 is formed.

In the figure, symbols C7 and C7 are circular holes B extending from both ends in the width direction.
It is a high-strength graphite-based composite part mainly composed of graphite formed in the area up to the periphery of the graphite and containing boron carbide dispersed in the graphite. It is a graphite-based composite part with excellent sliding properties that contains metal boride or metal boride and boron carbide dispersed therein.

The cylindrical cage A manufactured in this manner is suitable for use as a cage for the angular contact ball bearing shown in FIG.

In the figure, numeral 3 is an angular ball bearing, 4 is an outer ring, and 5 is an angular ball bearing.
is an inner ring, and 6 is a rolling element (ball) fitted into and held in a circular hole B of the cage A.

(b) A method for manufacturing a cage having the second configuration.

(First step) A graphite mold 2 having a hollow cylindrical part 1 on the inner surface and a core rod 8 in the center is prepared, and the mixed powder (2) is uniformly filled into the hollow cylindrical part 2 of the graphite mold 1 to a predetermined height. Press powder (8th step)
In the figure, symbol ■).

(Second step) On top of the compacted mixed powder (1), any one of the above-mentioned mixed powder (2), mixed powder (2), or mixed powder (2) is uniformly filled to a predetermined height, and the powder is compacted (see Fig. 8). , symbol ■ or ■ or ■), a two-layer green compact consisting of mixed powder ■-mixed powder ■ (or mixed powder ■ or mixed powder ■) is formed in the hollow cylindrical portion 1.

Thereafter, through the same process as above, a region of a predetermined width in the width direction from one end is made of a high-strength graphite-based composite composed mainly of graphite with boron carbide dispersed in the graphite, and the other region is made of graphite. Forming a sintered cylindrical body made of a graphite-based composite with excellent sliding properties, which is mainly composed of graphite and contains a metal boride in the graphite, or a graphite-based composite which is mainly composed of graphite and contains metal borides and boron carbide dispersed in the graphite. .

The outer peripheral surface of the sintered cylindrical body obtained in this way, that is, the graphite-based composite part with excellent sliding properties, which is mainly composed of graphite and contains metal boride or metal boride and boron carbide dispersed in the graphite. By machining, a plurality of circular holes are formed regularly in the circumferential direction with the peripheral edges in contact with the joint surface, and a groove is formed that is continuous with the circular holes and opens at the other end, and as shown in FIGS. A cylindrical retainer A1 is formed which includes a plurality of circular holes B made of a graphite-based composite shown in the figure and a groove communicating with the circular holes B and opening at the other end surface.

In the figure, the symbol CI indicates a circular hole B in the width direction from one end.
This is a high-strength graphite-based composite part mainly composed of graphite and containing boron carbide dispersed in the graphite formed in the area up to the periphery of the graphite. A graphite-based composite part containing dispersed boride and boron carbide with excellent sliding properties.

The cylindrical cage AI manufactured in this manner is suitable for use as a cage for a deep groove ball bearing shown in FIG.

In the figure, reference numeral 7 is a grooved ball bearing, 4 is an outer ring, 5 is an inner ring, and 6 is a rolling element (ball) fitted into a circular hole B of the retainer A through a groove and held therein.

(c) A method for manufacturing a cage having the third configuration.

(First step) A cylindrical green compact having a predetermined inner diameter is formed using the mixed powder (1).

(Second step) Using any of the mixed powders (1), (2), and (2), the powder has an inner diameter equal to the outer diameter of the cylindrical powder compact obtained in the first step and has a wall thickness. A cylindrical green compact is formed.

(Third Step) A cylindrical powder compact having an inner diameter equal to the outer diameter of the cylindrical powder compact obtained in the second step is formed using the mixed powder (1).

(Fourth step) Hollow cylinder g of graphite mold 2! The cylindrical green compacts obtained in the first, second and third steps are press-fitted into the outer peripheral surface of the inner core rod 8 in order, and the polymer of the cylindrical green compact is placed inside the hollow cylindrical part l. (In FIG. 11, the symbol ■ is the cylindrical compact obtained in the first step and the third step, and the symbol ■ is the cylindrical compact obtained in the second step.)

(Fifth step) The polymer of the cylindrical green compact formed in the hollow cylindrical portion 1 of the graphite mold 2 is sintered under the above-mentioned pressure and heat sintering conditions to obtain a circle Wi sintered body. .

The cylindrical sintered body thus obtained has a predetermined width region in the radial direction from the inner and outer peripheries, respectively, made of a high-strength graphite-based composite mainly composed of graphite and containing boron carbide dispersed in the graphite, The other regions are formed of a graphite-based composite which is mainly composed of graphite and contains a metal boride or a metal boride and boron carbide dispersed in the graphite and has excellent sliding properties.

A plurality of circular holes are regularly formed in the circumferential direction in the central part of this cylindrical sintered body, that is, a graphite composite part with excellent sliding properties, and a plurality of circular holes made of the graphite composite as shown in Fig. 9 are formed regularly in the circumferential direction. A cylindrical cage A2 with B is formed.

In the figure, C1 and CI are high-strength graphite-based composite parts in which regions of a predetermined width in the radial direction from the inner and outer edges, respectively, are mainly composed of graphite and contain boron carbide dispersed in the graphite, and C2 is a high-strength graphite composite portion. It is a graphite-based composite part mainly composed of graphite and containing a metal boride or a metal boride and boron carbide dispersed in the graphite and having excellent sliding properties.

The cylindrical cage A2 manufactured in this manner is suitable for use as a cage for a thrust ball bearing shown in FIG.

In the figure, reference numeral 8 is a thrust ball bearing, 4 is an outer ring, 5 is an inner ring, and 6 is a rolling element (ball) fitted and held in a circular hole B of the cage A2.

In the mixed powder (2) that forms the high-strength part of the cage in each of the above-mentioned manufacturing methods, the boron carbide powder that is blended with the calcined pitch coke powder, which is the main component, is added to the coke during the pressure and heat sintering process. In addition to playing a role in accelerating graphitization and sintering of the powder, it is also dispersed in the resulting sintered body (graphite body) to improve the mechanical strength of the sintered body and to improve its acid resistance in high-temperature regions. Contributes to improved wearability.

This effect of boron carbide as a graphitization promoting effect and a sintering promoting effect appears when the blending ratio is around 3% by weight with respect to the coke powder, but with this amount, boron carbide is Since all of the boron is dissolved in the coke and is not present in the obtained sintered body, the above-mentioned improvement in the mechanical strength of the sintered body and the improvement in oxidative consumption resistance in the high temperature range are insufficient.

Therefore, in order to impart desirable properties to the graphite-based composite forming the high-strength portion of the cage, it is necessary to blend at least 5% by weight of boron carbide into the coke.

By blending this boron carbide in an amount of 5% by weight or more with respect to the coke, a graphite composite containing boron carbide dispersed in the sintered body can be obtained, which has the mechanical strength required for the high-strength part of the cage. , the oxidative wear resistance can be improved.

However, if the blending ratio of boron carbide exceeds 40% by weight, the mechanical strength tends to decrease.

Therefore, the blending ratio of boron carbide to coke is 5 to 40% by weight, preferably 10 to 30% by weight.

In the mixed powder (■) that forms the part of the cage with excellent sliding properties, elements from groups IVa, Va, and VI of the periodic table are blended into the calcined pitch coke powder, which is the main component.
Similar to the boron carbide described above, the boride powder of group a metal plays a role in accelerating graphitization and sintering of the coke powder in the pressure/heat sintering process, and also plays a role in promoting the graphitization and sintering of the coke powder. It is dispersed and contained in the aggregate (graphite body) and contributes to improving the friction and wear characteristics, especially in high-temperature regions.

This metal boride itself does not exhibit lubricating properties like graphite or molybdenum disulfide, but by being dispersed in the graphite sintered body, it forms a solid lubricant (graphite) film on the surface of the mating material. It promotes durability, increases the durability of the coating in dry friction, and improves the friction and wear characteristics.
This tendency is remarkable in high temperature regions.

The appropriate blending ratio of the metal boride to the coke is 5 to 20% by weight, preferably 10 to 15% by weight.

If this metal boride is blended in an amount exceeding 20% by weight with respect to the coke, a large proportion of the metal boride is exposed on the surface (sliding surface) of the sintered body, resulting in a decrease in friction and wear characteristics.

In addition, the mixed powder (■) that forms the part of the cage with excellent sliding properties is a mixture of the above-mentioned mixed powder (■) and boron carbide powder, which improves the strength of the graphite-based composite formed from the above-mentioned mixed powder (■). It is something that improves.

Then, for the calcined pitch coke powder which is the main component,
Suitable amounts of boride powder of metals from Groups IVa, Va, and Group VIa of the Periodic Table of the Elements are 5 to 20% by weight, and 5 to 20% by weight of boron carbide powder.

In addition, in the mixed powder (■) that forms the portion with excellent sliding properties of the cage, elements from Groups (A), Va, and VIa of the Periodic Table are added to the calcined pitch coke powder, which is the main component. During the pressurized and heated sintering process, the metal carbide powder reacts with the boron carbide in the presence of the boron carbide powder mixed with the metal carbide to form a metal boride. A metal boride or metal boride and boron carbide are dispersed in the body, and like the graphite-based composite formed from the mixed powder (1) mentioned above, it contributes to improving the friction and wear characteristics in the high temperature range.

Then, for the calcined pitch coke powder which is the main component,
Carbide powder of metals from Group IVa, Group Va and Group VIa of the Periodic Table of Elements is 5 to 20% by weight, and boron carbide powder is the same or more than the metal carbide powder in an amount of 5 to 20% by weight.
It is appropriate to mix it within the range of weight %.

When the blending ratio of this metal carbide powder and boron carbide powder is the same, the metal carbide powder reacts with boron carbide under pressure and heat sintering, and all of the metal carbide powder changes into metal boride and is dispersed in graphite. If the amount of metal carbide powder is less than the amount of boron carbide powder, metal boride and boron carbide that react with boron carbide under pressure and heat sintering are dispersed in graphite. We have confirmed that this will be done.

The table below shows the results of testing the mechanical strength (flexural strength) and friction and wear characteristics in a high temperature range (500° C.) of a graphite-based composite formed from the above-mentioned mixed powder.

(Left space below) The friction and wear characteristics in the table are the results of testing under the following test conditions.

Test conditions〉 Dimensions of graphite composite: length 20 mm, width 20 mm, block-like partner with thickness 7III l Material: outer diameter 18 mm, inner diameter 14 nv+, length 2 (
Cylindrical body made of 1wn+ stainless steel Load: 20 kg/Ctn' speed
Degree: 5n+/win Test Machine: Precious wood type thrust tester The amount of wear is the value measured after 10 hours of testing time.

"Actions/Effects" The high temperature rolling bearing retainer of the present invention having the above-described configuration has the following specific effects.

Since the rolling contact portion with the rolling element is made of a graphite-based composite material with excellent sliding properties, especially when used in high-temperature areas, a graphite coating is formed on the surface of the rolling element from the cage, and the rolling element is While being guided, a graphite coating is transferred and formed from the rolling elements on the raceway surface of the outer ring, so that stable rolling contact is achieved.

Further, since the peripheral portion of the circular hole is formed of a high-strength graphite composite, the portion will not be cracked or damaged when the rolling element is fitted into the circular hole.

"Example" Examples of the present invention will be described below.

This example concerns a cage used for deep groove ball bearings.

(Adjustment of raw material powder) Blend 30% by weight of boron carbide powder bundles with an average particle size of 1.5 μm into calcined pitch coke powder with a particle size of 150 μm or less, and mix to obtain a uniform mixed powder of the coke powder and boron carbide powder. (hereinafter referred to as "mixed powder ■").

Next, 15% by weight of chromium diboride powder (group IVa of the periodic table of elements) with an average particle size of 7 μm is added to calcined pitch coke powder with a particle size of 150 μm or less, and the coke powder and chromium diboride (CrB2) are mixed. ) A uniform mixed powder of powders was obtained (hereinafter referred to as "mixed powder ■").

(Manufacturing method) A graphite mold 2 having a hollow cylindrical portion 1 on the inner surface and a core rod 8 in the center is prepared, and the mixed powder (1) is filled into the hollow cylindrical portion l of the graphite mold 2 and compacted to form the hollow cylinder. Mixed powder in part l■
After forming a green compact, the mixed powder (2) is uniformly filled on the green compact, and the powder is compacted to form a two-layer compaction consisting of the mixed powder (1) and the mixed powder (2) in the hollow cylindrical portion 1. The two-layer green compact formed in the hollow cylindrical portion 1 (FIG. 8) was pressurized and heated at a temperature of 2200° C. under a pressure of 220 kg/cm” and sintered. A sintered cylindrical body (graphite body) in which two layers of green compacts were integrated was obtained.

In this pressurized and heated sintering process, the calcined pitch coke is graphitized, and the 0 part of the mixed powder in the cylindrical body is mainly composed of graphite.
A graphite-based composite is formed in which boron carbide is dispersed in the graphite, and a graphite-based composite in which the zero portion of the mixed powder is mainly composed of graphite and chromium diboride is dispersed in the graphite.

The sintered cylinder thus obtained had an outer diameter of 22.3 mm.
, inner diameter 17mm, width 7.1mm (mixed powder 0
The width of the part was machined to a dimension of 1° (1 mm).

Next, circular holes with a diameter of 4.86 mm were regularly formed in the circumferential direction in the mixed powder 0 portion of the sintered cylinder having the above dimensions so that the periphery was in contact with the joint surface of mixed powder (2) and mixed powder (2). A groove with a width of 4.65 mm was formed that was continuous with the hole and opened on the end face opposite to the mixed powder (1), thereby obtaining a cage made of a two-layered graphite-based composite (FIG. 6).

This retainer has an outer ring outer diameter of 28 mm and an inner ring inner diameter of 121 mm (both the outer ring and inner ring are made of stainless steel TS (made of SLJS440C)).
) to form a deep groove ball bearing (Fig. 7).

The friction and wear characteristics of the deep groove ball bearing thus formed were tested under the following conditions.

Test conditions> Bearing temperature: 300℃ Rotation speed: 1100rp
Radimo test Il: Radial journal tester manufactured by Orientic Co., Ltd. (^FT-9-1) From the above test, the rolling friction coefficient is 0.008 to 0°O
1. The maximum amount of bearing wear (radial clearance) was 60t1m.

After the test, it was confirmed that a thin film of graphite was formed on the raceway surfaces of the inner and outer rings and on the surfaces of the balls.Furthermore, no damage was observed to the cage made of graphite-based composite after the test. Ta.

On the other hand, a similar cage was formed from graphite alone and a similar test was conducted, but this cage was found to be damaged after the test.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing a cage for angular contact ball bearings, Figure 2
The figure is a vertical cross-sectional view, Figure 3 is a vertical cross-sectional view showing an angular contact ball bearing, Figure 4 is a vertical cross-sectional view showing a method for manufacturing the cage shown in Figure 1, and Figure 5 is a retainer for deep groove ball bearings. FIG. 6 is a vertical cross-sectional view of the container, FIG. 7 is a vertical cross-sectional view of the deep groove ball bearing, FIG. 8 is a vertical cross-sectional view showing the method of manufacturing the cage shown in FIG. Figure 9 is a plan view showing the cage for thrust ball bearings, Figure 10 is a longitudinal sectional view showing the thrust ball bearing, and Figure 1
FIG. 1 is a longitudinal sectional view showing a method of manufacturing the cage shown in FIG. 9. Explanation of symbols 1: Hollow cylindrical part 2: Graphite type A, AJ, A2: Cage B: Circular hole C1: High strength graphite composite part C2: Graphite composite part with excellent sliding characteristics Patent applicant
Oiles Industries Co., Ltd.Figure 2Figure 3Figure 8Figure 4Figure 5Figure 9

Claims (1)

[Scope of Claims] (1) A cylindrical cage that fits and holds rolling elements that are rolled and guided between raceways of an inner ring and an outer ring, the rolling elements being fitted and held on the circumferential surface of the cage. A plurality of circular holes are formed to hold the cage, and the area from both ends of the cage to the periphery of the circular holes in the width direction is made of a high-strength material mainly made of graphite and containing boron carbide dispersed in the graphite. It is made of a graphite-based composite, and the other area is made of a graphite-based composite that has excellent sliding properties, mainly consisting of graphite and containing metal borides or metal borides and boron carbide dispersed in the graphite. A cage for a high-temperature rolling bearing, characterized by: (2) A cylindrical cage that fits and holds the rolling elements that are rolled and guided between the raceway surfaces of the inner ring and the outer ring, and the cage has a plurality of circles on the circumferential surface that fit and hold the rolling elements. A hole is formed to communicate with a groove opening on one end surface of the retainer,
The area of the cage from the end surface opposite to the groove to the periphery of the circular hole in the width direction is formed of a high-strength graphite-based composite mainly composed of graphite and containing boron carbide dispersed in the graphite. ,
A claim characterized in that the other region is integrally formed of a graphite-based composite having excellent sliding properties, which is mainly composed of graphite and contains a metal boride or a metal boride and boron carbide dispersed in the graphite. A cage for a high-temperature rolling bearing according to item 1. (3) A cylindrical cage that fits and holds the rolling elements that are rolled and guided between the raceway surfaces of the inner ring and the outer ring, and the rolling elements are fitted and held in the end face of the cage in the circumferential direction. A plurality of circular holes are formed in the cage, and the regions from the inner and outer edges to the respective peripheral edges of the circular holes are made of high-strength graphite mainly composed of graphite and containing boron carbide dispersed in the graphite. The other area is made of a graphite-based composite with excellent sliding properties, mainly composed of graphite and containing metal boride or metal boride and boron carbide dispersed in the graphite. The cage for a high-temperature rolling bearing according to claim 1, characterized in that: (4) High-strength graphite-based composites are made by pressurizing, heating and sintering a mixed powder consisting mainly of calcined pitch coke powder and 5 to 40% by weight of boron carbide powder. The retainer for a high-temperature rolling bearing according to any one of claims 1 to 3, characterized in that it is made of a solid body. (5) Graphite-based composites with excellent sliding properties are mainly composed of calcined pitch coke powder and contain elements from IVa of the periodic table of elements.
Boride powders of metals of groups Va and VIa
The cage for a high-temperature rolling bearing according to any one of claims 1 to 3, characterized in that it is made of a sintered body formed by pressurizing and heating sintering a mixed powder containing 20% by weight. (6) Graphite-based composites with excellent sliding properties are mainly composed of calcined pitch coke powder,
Formed by pressurizing and heating sintering a mixed powder containing 5 to 20% by weight of metal boride powder and/or metal carbide powder of Group Va, Group VIa, and 5 to 20% by weight of boron carbide powder. The cage for a high-temperature rolling bearing according to any one of claims 1 to 3, characterized in that it is made of a sintered body.