JPH10204652A - Multilayer sliding bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multilayer sliding bearing having an inorganic compound coating layer excellent in heat resistance and wear resistance without executing overlay plating treatment by forming an amorphous coating layer composed of metallic oxide or water soluble or hardly soluble salt on the surface of a bearing alloy layer. SOLUTION: A lining layer 2 composed of a bearing alloy is formed on the base metal 1 of a sliding bearing. An amorphous inorganic compound coating layer 3 having a smooth surface is formed on the lining layer 2 by a chemical conversion treating method or an electrolytic treating method. As for the coating layer 3, its structure is the one having fine cracks 5, lubricating oil is impregnated and held into the part of the cracks 5, and seizure is hard to be generate even in the state of being poor in lubricating oil. It is preferable that the inorganic compound coating layer contains at least one kind of metallic compounds selected from among Mo, W, Cr, Ti and Zr. The bearing has good slidability and conformability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding bearing used for transportation machines such as automobiles and ships, general industrial machines and the like. More specifically, the present invention relates to a plain bearing suitable for an engine crankshaft.

[0002]

2. Description of the Related Art Sliding bearings used in engines and the like are:
Generally, a bimetal in which a lining layer made of a bearing alloy is joined to a steel back metal is processed into a cylindrical bush or a half-shaped bearing.

[0003] Aluminum alloys and copper alloys are mainly used as bearing alloys. In order to improve the conformability (slidability with a mating member to be brought into contact), fatigue resistance and wear resistance. In addition, Sn and Pb
It has been necessary to form an overlay layer by electroplating a soft metal or alloy such as the above to a thickness of about 5 to 30 μm.

[0004] Bearing alloys requiring such an overlay plating layer include aluminum alloys such as J
IS H5402 AJ-1 (10% Sn-0.75C
u-0.5Ni-Al Bal), JIS H540
2 AJ-2 (6% Sn-2.5Cu-1.0Ni-A
l Bal), and the copper-based alloy is JIS H5
403 KJ3 (70% Cu-30% Pb-Sn),
KJ4 (76% Cu-24% Pb-Sn) and the like.

However, even in bearings in which a soft metal is overlay-plated on these bearing alloys, lubrication occurs when sliding under high load conditions is performed due to the low heat resistance and wear resistance of the overlay plating layer. Since the temperature of the oil rises and the lubricating surface becomes high in temperature, inconvenient phenomena such as fatigue and seizure occur in the sliding bearing, which may make it unusable.

In the manufacture of a plain bearing, a method of performing an electroplating step after a machining step requires many steps in the manufacturing process, and has a problem that productivity is reduced and cost is increased. .

On the other hand, instead of forming an overlay plating layer, it is known to apply a chemical treatment film having excellent heat resistance to the slide bearing surface, for example, as disclosed in European Patent EP-P.
In S0059273 and JP-A-64-49713, there are synthetic plain bearings having such a chemical conversion coating.

[0008] The sliding bearing described in the above-mentioned European patent specification is a method in which a zinc phosphate solution treatment is applied to the bearing surface of an aluminum alloy bearing material to form a zinc phosphate crystal film on the bearing alloy surface, thereby localizing the load. The purpose of this method is to prevent local concentration, apply a uniform load to the bearing surface, and improve conformability. The plain bearing of the above-mentioned publication further improves the plain bearing of the above-mentioned European Patent and prevents the formation of a zinc phosphate film on the outer peripheral surface of the bearing, thereby reducing the former disadvantage, namely, loosening when fixed to the bearing housing. This is what was prevented.

As a chemical conversion treatment for a copper-based alloy bearing, Japanese Patent Application Laid-Open No. 57-186620 discloses a technique in which a copper-based alloy bearing is immersed in a ferric chloride solution to form a copper chloride film.

However, in the above-mentioned aluminum alloy bearing on which a zinc phosphate film is formed, the formed zinc phosphate is crystalline having a particle size of several μm to several tens μm, so that the bearing surface has irregularities. However, there is a problem in that contact friction (boundary lubrication) is generated between the uneven surface and the shaft surface, so that the sliding resistance is large, and the seizure resistance and abrasion resistance become insufficient under a high load. Was.

On the other hand, in a copper-based alloy bearing disclosed in Japanese Patent Application Laid-Open No. 57-186620, a method of immersing the same in a ferric chloride solution to form a copper chloride film is also disclosed.
Cupric chloride was not satisfactory in its bearing performance because it was crystalline like zinc phosphate and it was water-soluble and unstable.

The bearing alloy is made of alloy base metal such as aluminum or copper and soft metal such as tin or lead alloyed at a constant composition ratio. It is contained.

Because of having such a special composition,
For bearing alloys, it is difficult to form a good film on the bearing alloy with conventional surface treatment liquids that have been used for applications such as rust prevention and coloring. Particularly, aluminum alloys and copper alloys (Kelmet It was difficult to form a chemical conversion coating having good performance on any of the above.

However, inorganic compound coatings, particularly inorganic oxide coatings, generally undergo less change in physical properties due to heat than soft metals, and are often excellent in wear resistance. Further, it is advantageous in that a film can be formed only by a chemical reaction without requiring electric power or electrolytic equipment for forming the film. Therefore, development of means for forming an inorganic compound film having excellent performance by chemical conversion treatment has been desired.

[0015]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional chemical conversion-treated bearing, and performs overlay plating on a sliding bearing having a lining layer made of an aluminum alloy or a lining layer made of a copper alloy. An object of the present invention is to provide a multilayer plain bearing having an inorganic compound film layer having more excellent heat resistance and wear resistance. Further, the present invention is intended to provide a multilayer plain bearing having the inorganic compound film and an overlay layer and having higher performance than the conventional one.

[0016]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors prepared various chemical conversion treatment solutions for aluminum alloy bearings and copper alloy bearings, and formed various chemical conversion treatments on the surface of the bearing alloy lining layer. After forming a treated film, the bearing performance was intensively studied.

As a result, when a conventionally known crystalline compound film such as zinc phosphate, sodium aluminum fluoride and manganese phosphate is formed on the bearing surface,
The bearing surface is covered with coarse crystals with a crystal diameter of about 2 to 4 μm, which reduces the smoothness of the bearing surface, increases the frictional resistance between the shaft and the bearing during operation, and causes seizure under high load. Was found to easily occur.

Based on these findings, the inventors of the present invention formed a substantially amorphous film containing molybdenum oxide as a main component from an aqueous solution containing molybdate by a chemical conversion treatment or an electrolytic treatment. And the performance of the obtained bearing was examined. As a result, it has been newly found that this bearing exhibits good slidability and conformability which could not be obtained by a conventional crystalline inorganic film such as a zinc phosphate film.

Further, the present inventors further form a film containing amorphous phosphate as a main component on a bearing alloy surface from a phosphating solution containing a small amount of a chromium group metal compound by a similar method. As a result of examining the bearing performance, it was confirmed that the bearing performance was similarly excellent. In addition, the performance of bearings in which a substantially amorphous coating layer made of a metal oxide of various compositions or a water-insoluble or poorly water-soluble salt was formed on the surface of the bearing alloy layer was evaluated and examined. In comparison, it was confirmed that they had better seizure resistance and wear resistance.

The inventors also examined the relationship between the structure of these films formed on the bearing alloy surface by observation with an electron microscope and the film performance, and found that these amorphous films had fine cracks. In this case, the crack portion was impregnated with the lubricating oil and held, so that even when the lubricating oil was insufficient, it was revealed that the film exhibited excellent performance that seizure hardly occurred.

Further, the present inventors further examined the possibility of further improving the performance of the sliding bearing having the inorganic compound film layer by forming the sliding bearing into three or more layers. , A metal oxide, or provided with an inorganic compound film layer comprising a water-insoluble or poorly water-soluble salt,
Furthermore, a multilayer slide bearing with an overlay layer made of a soft metal or solid lubricant as the outermost layer was fabricated on it, and the performance was evaluated.As a result, only the film made of the soft metal or solid lubricant was coated on the bearing alloy lining. They have been found to exhibit better wear resistance and seizure resistance than when formed directly.

On the contrary, a layer composed of a soft metal or a solid lubricant is provided as an intermediate layer on the bearing alloy lining layer, and an amorphous metal oxide or water-insoluble or hardly water-soluble layer is further formed thereon. A bearing provided with an inorganic compound film layer made of a salt as an outermost layer was also manufactured and evaluated, and as a result,
The present invention was found to exhibit better wear resistance than when only a soft metal or solid lubricant film was formed on a bearing alloy lining, and completed the present invention.

That is, the multilayer plain bearing of the present invention (hereinafter referred to as the first
The multi-layer slide bearing of the invention) is characterized in that a lining layer made of a bearing alloy has a substantially amorphous metal oxide or an inorganic compound coating layer made of a water-insoluble or hardly water-soluble salt. Things. Further, another multi-layer slide bearing of the present invention (hereinafter referred to as a multi-layer slide bearing of the second invention).
On a lining layer made of a bearing alloy, a substantially amorphous metal oxide, or an inorganic compound film layer made of a water-insoluble or poorly water-soluble salt, and a lubricating layer made of a soft metal or a solid lubricant, It is characterized in that the layers are formed in an arbitrary order. In the multilayer plain bearing of the first and second inventions, it is preferable that microcracks are formed in the inorganic compound film layer, particularly in the inorganic compound film layer forming the outermost layer. In the multilayer plain bearing of the present invention, it is preferable that the inorganic compound film layer contains a compound of at least one metal selected from Mo, W, Cr, Ti and Zr.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION As a kind of a bearing alloy usable in the present invention, when it is an aluminum alloy, JIS
H5402 AJ-1 (10% Sn-0.75Cu-
0.5Ni-Al Bal) or JIS H5402
AJ-2 (6% Sn-2.5Cu-1.0Ni-Al
Aluminum alloys such as Al-Sn-Cu-based alloys such as Bal), Al-Si alloys, Al-Sn-Si-Pb-Cu alloys, Al-Pb alloys, and Al-Zn-Si-Cu-Pb alloys Can be used. In the case of a copper alloy, JIS H5403 KJ3 (70% Cu-3
0% Pb-Sn) and KJ4 (76% Cu-24% Pb)
-Sn) can be used.

These bearing alloys are laminated on a steel back metal (back metal) such as low carbon steel, high carbon steel, stainless steel, special steel, etc. to form a bimetal. The lining layer is bent and surface-finished so as to be an inner surface (sliding surface). In the present invention, the inorganic compound film layer and, if necessary, the lubricating layer are formed on the lining layer (on the sliding surface side). The formation of the inorganic compound film layer and the lubricating layer is more preferably performed on the surface after the bending and finishing processes are completed, but the film forming process may be performed in an unprocessed bimetal state.

In the first and second inventions, the thickness of the inorganic compound film layer is preferably in the range of 0.1 to 8 μm, more preferably in the range of 0.3 to 2 μm. If the thickness is less than 0.1 μm, the wear resistance may be insufficient, and if it exceeds 8 μm, the film adhesion may be insufficient.

In the first invention and the second invention,
The metal oxide or the water-insoluble or poorly water-soluble salt constituting the inorganic compound film layer needs to be amorphous or extremely low in crystallinity, and is a double oxide of two or more metals or It may be a mixture of a metal oxide and a water-insoluble or poorly water-soluble salt, or may contain water of hydration. The crystallinity of the inorganic compound film component is confirmed by the fact that no clear peak derived from the film is detected by thin film X-ray diffraction. There are no particular limitations on the type of amorphous metal oxide, but molybdenum, tungsten, chromium,
Aluminum, manganese, copper, titanium, zirconium,
Oxides such as vanadium, iron, cobalt, nickel, tin, bismuth, magnesium, and calcium can be used, with molybdenum, tungsten, chromium, and aluminum oxides being particularly preferred. The water-insoluble or poorly water-soluble salt that can be used in the present invention is not particularly limited as long as it is insoluble or hardly soluble in water. It is preferable to use salts, sulfates and the like, and the solubility product thereof is 25
Those which are less than 10 ^-8 at ° C are preferred.

In the first and second inventions, the inorganic compound film layer preferably has microcracks, and the average value of the diameters of the individual island-like film portions divided by the microcracks is 1 to 80 μm. Preferably, there is. These microcracks can hold the lubricating oil impregnated, thereby further improving the sliding performance of the plain bearing. If the average value of the diameters of the microcracks exceeds 80 μm, the lubricating oil retaining effect of the microcracks may be insufficient. If the average value is less than 1 μm, the number of microcracks becomes excessive and the wear resistance of the film becomes poor. May be insufficient. Further, the interval between adjacent island-shaped portions (width of valleys (cracks)) is more preferably 0.01 to 2 μm.

In the multilayer plain bearing of the second invention, an inorganic compound film layer is formed as an intermediate layer on the bearing alloy lining layer, and a lubricating layer made of a soft metal or a solid lubricant is formed thereon as an overlay layer. ing.
The intermediate layer composed of the inorganic compound film may be a single layer composed of a single composition, or a multilayer composed of different compositions. Also, the overlay layer may be a single layer,
Alternatively, it may be a multilayer having compositions different from each other. That is, the multilayer plain bearing of the second invention has a laminated structure of three or more layers including the bearing alloy lining layer, and may have a laminated structure of four or more layers. For example, the case where the overlay layer includes a lower layer of a soft metal and an upper layer of a solid lubricant is also included in the second invention.

The inorganic compound coating layer on the bearing alloy lining layer must be a metal oxide or a water-insoluble or poorly water-soluble salt, and must be amorphous or low-crystalline, that is, substantially amorphous. It is preferable to use a compound film having a crystal grain size of 0.02 μm or less. For example, it may contain crystals such as zinc phosphate, calcium phosphate, aluminum phosphate, copper phosphate, and manganese phosphate, but preferably has a surface roughness Rz of less than 3 μm. In addition, it is preferable that the inorganic compound film also has the same microcracks as in the first invention, in order to improve the adhesion of the overlay layer formed of a solid lubricant layer or the like.

In the second invention, the soft metal is tin,
Lead, zinc, indium, silver, etc. can be used, and these alloys may be used, or a small amount of copper,
It is allowed to contain antimony and bismuth. As the solid lubricant used in the second invention, metal sulfide particles,
Particularly preferably, metal sulfide particles such as molybdenum disulfide and a fluorine-based resin, particularly preferably polytetrafluoroethylene mixed with a heat-resistant resin such as polyamide or polyimide are preferable.

Further, in the multilayer plain bearing of the second invention, a lubricating layer made of a soft metal or a solid lubricant is formed as an intermediate layer on the bearing alloy lining layer, and an amorphous or microcrystalline lubricating layer is further formed thereon. An outermost layer composed of an inorganic compound film composed of a metal oxide or a water-insoluble or poorly water-soluble salt may be formed. The soft metal or solid lubricant used for the intermediate layer is the same as described above, but when a soft metal is used, nickel, cobalt,
Alternatively, a plating layer of iron or the like or an inorganic compound film layer is preferably formed as a diffusion preventing layer. On this lubricating intermediate layer,
Further, as the uppermost layer, the inorganic compound film layer made of a metal oxide or a water-insoluble or poorly water-soluble salt is formed.

In the bearing of the present invention, the inorganic compound film layer is most simply and suitably formed by a chemical conversion treatment or an electrolytic treatment using an aqueous treatment solution. ), PVD method (physical vapor deposition method), normal pressure CVD method (pyrosol method), or thermal spraying method. Further, it is preferable to use a vapor deposition method or a plating method to form the soft metal layer, and to form the solid lubricant layer, a spray method using a coating liquid,
It is preferable to use a coating method by dipping or brushing.

The sliding bearing of the present invention has a metal oxide or an inorganic compound film layer made of a water-insoluble or hardly water-soluble salt on a lining layer made of a bearing alloy. The seizure resistance of the obtained bearing is improved. When this film forms the uppermost layer, this film is amorphous or microcrystalline, so that its surface has a low coefficient of friction and exhibits good bearing performance.

When a microcrack is formed on the inorganic compound film, the film is easily deformed following the deformation of the bearing alloy surface, and lubricating oil can be contained and retained in the crack portion. In particular, it can exhibit good conformability to a sliding partner member, and can exhibit good seizure resistance even in a greasy state.

Also, in the multilayer plain bearing of the second invention, when the inorganic compound film forms an intermediate layer, even if it contains a microcrystalline compound, it exhibits good sliding characteristics as a reason. Even if the inorganic compound coating layer has a certain degree of unevenness, the overlay layer made of a soft metal or solid lubricant layer can be uniformly formed on this layer to reduce the frictional resistance of the sliding surface of the sliding bearing, thereby preventing burning. This is because it is possible to improve the stickiness. It is preferable that this inorganic compound film also has the same microcracks as in the first invention from the viewpoint of the adhesion of the overlay layer formed of a solid lubricant layer or the like.

An embodiment of the multilayer plain bearing according to the present invention is illustrated in FIGS. In the sliding bearing of FIG. 1, a lining layer 2 made of a bearing alloy is formed on a base metal 1, and an inorganic compound film layer 3 having a smooth surface is formed thereon. In the sliding bearing of FIG. 2, many microcracks 5 are formed in the inorganic compound film layer 3. In the plain bearing of FIG.
An inorganic compound film layer 3 is formed thereon, and a lubricating layer 4 made of a soft alloy or a solid lubricant is formed thereon as an overlay layer. In the sliding bearing of FIG. 4, a lubricating layer 4 made of a soft metal or a solid lubricant is formed between an inorganic compound film layer 3 and a bearing alloy lining layer 2. Further, in the multilayer plain bearing of the embodiment shown in FIGS. 3 and 4, it is preferable that the inorganic compound film layer has microcracks.

[0038]

The present invention will be specifically described with reference to the following Examples and Comparative Examples.

Examples 1 to 20 and Comparative Examples 1 to 4 Test base material (A) Aluminum alloy for bearing (Al-6%
(B) Bearing base material made of a bimetal manufactured by rolling and joining an Sn-1% Cu-Ni) thin plate by a roll rolling method and then performing an annealing process. (B) Copper alloy for bearing (Kelmet: 76% Cu-24%)
Pb-Sn) Rolling joining of thin plates by the roll rolling method, and then annealed bimetal bearing base material

2. Processing Step Next, the bearing base material (A) or (B) is cut and machined to prepare a bearing test piece, which is then subjected to alkaline degreaser (registered trademark: Fine Cleaner 315, manufactured by Nippon Parkerizing Co., Ltd.). Was used as a treatment liquid, degreased at 70 ° C. for 2 minutes, washed with water, and further subjected to coating treatment on the bearing alloy lining layer as described below.

Table 1 shows the coating compositions, coating structures and film thicknesses of Examples 1 to 15, and Table 2 shows Examples 16 to 20 and Comparative Examples 1 to 4. As the test bearing substrate, Examples 1 to
3, Examples 5 to 6, Examples 9 to 11, and Examples 13 to 1
In Example 4, Example 16, Example 18, Example 20, and Comparative Examples 1 and 3, the aluminum alloy base material (A) was used, and Examples 4, Examples 7 to 8, Example 12, and Example 1 were used.
In Examples 5, 17, 19, and Comparative Examples 2 and 4, the copper alloy substrate (B) was used.

3. Formation of Inorganic Compound Layer The formation of the inorganic compound layer was performed in Example 4, Example 6, and Example 1.
9 was carried out by cathodic electrolysis (a).
0 and Comparative Example 2 were performed by a method (b) of applying and drying a chemical conversion aqueous solution containing a film component, and all other Examples and Comparative Examples were performed by a method of dipping in a chemical conversion solution (c). In the cathodic electrolysis method (a), a bearing substrate was used as a cathode, and a platinum-plated titanium plate was used as an anode, and electrolysis was performed at a current density of 0.8 A / dm ² for 1 to 2 minutes. The chemical conversion treatments (b) and (c) were performed at a liquid temperature of 75 ° C. for 240 seconds. Also,
In Example 17 and Comparative Example 4, the upper or lower tin film was formed by an electroplating method using a neutral tin plating solution, and the other tin films were treated with an acidic tin substitution plating solution to precipitate tin. Was. Further, the upper or lower layer of molybdenum disulfide + PTFE layer is composed of 75 parts by weight of molybdenum disulfide, 5 parts by weight of PTFE (polytetrafluoroethylene) and 20 parts by weight of polyimide resin (binder).
200 parts by weight of xylene,
Alternatively, a dispersion liquid is prepared by mixing a solvent such as 1,1-methyl-2-pyrrolidone, and the resulting aqueous dispersion is applied, dried, and baked (200 ° C., 30 minutes) to give a thickness of 5 to 10
It was formed on a μm coating layer.

The addition of the inorganic compound film-forming metal component to the treatment solution may be performed by adding molybdenum as a film component.
5 g / L ammonium molybdate is added to the processing solution, those containing tungsten are 3 g / L sodium tungstate, those containing chromium are 3 g
Per liter of ammonium bichromate, those containing calcium are added with calcium chloride, those containing zirconium or titanium are sulfated as 1 to
20 g / l were added. For those containing manganese, add 5 g / l to the treatment solution as manganese sulfate or potassium permanganate. For those containing zinc phosphate, use 24 g / l of a solution prepared by dissolving 30% of zinc oxide in phosphoric acid. 100 g / l was added. In addition to these components, 1.5 g / l of sodium hydrogen fluoride was added as an etching agent to the aluminum alloy substrate (A), and 5 g / liter to the copper alloy substrate (B).
One liter of thiourea was added. In Comparative Example 2, 5
An aqueous solution of 0 g / liter cupric chloride (easy soluble) was applied and dried at 100 ° C. to form a film.

4. Formation of Lubricating Layer Made of Soft Metal or Solid Lubricant In the case where a lubricating layer made of soft metal or solid lubricant is provided on the upper or lower layer of the inorganic compound coating layer (both are located on the bearing alloy lining layer), As the soft metal, a tin film formed by electroplating is used. As the solid lubricant, molybdenum disulfide and PT
A paint in which FE (polytetrafluoroethylene) was mixed with a polyimide resin as a binder was applied and baked before use.

5. Measurement of film properties Measurement of film thickness: The film thickness of the inorganic compound film layer after surface treatment is
The bearing after the treatment was cut, embedded in an embedding resin, and mirror-polished in cross section, and then measured on a measurement scale using a metallographic microscope. Judgment of micro crack: Whether micro crack exists
It was confirmed by observing the coating surface with an electron microscope at a magnification of 5000. The average diameter (film width) of the film portion divided by the microcracks and the microcrack groove width were measured using a scale. Analysis of film: The composition of the inorganic compound film formed by the surface treatment was determined from the results of EPMA (electron beam microanalyzer) analysis. The crystallinity was analyzed by a thin film method (X-ray incident angle 2 °) using an X-ray diffraction analyzer. As a result, no clear crystal peak was observed in the inorganic compound films of Examples 1 to 20, and thus it was determined that the film was amorphous or had a particle size of less than 0.02 μm. Comparative Examples 1 to
A clear crystalline peak was observed in the inorganic compound film of No. 3.

[0046]

[Table 1]

[0047]

[Table 2]

6 Bearing Performance Test The bearing test pieces of each of the comparative examples and examples were subjected to a seizure test and a wear test using a rotary load tester to evaluate the bearing performance. The conditions of the seizure test and the abrasion test are shown below, and the test results are shown in FIGS.

[Seizure test conditions] Test apparatus: Static load bearing tester Rotation speed: 5000 rpm Lubrication amount: 0.1 liter / min Circumferential speed: 12.5 m / sec Lubricating oil: SAE 10W-30 Lubrication temperature: 100 ± 2 ° C. Shaft material: S50C (quenched, surface roughness Rz: 0.8 μm) Judgment method: The load was measured when the back surface temperature of the bearing rapidly increased or when the motor was overloaded.

[Wear test conditions] Test apparatus: Static load bearing tester Revolution: 5000 rpm Oil supply amount: 0.1 liter / min Circumferential speed: 12.5 m / sec Lubricating oil: SAE 10W-30 Surface pressure: 50 MPa Shaft material : S50C (quenching, surface roughness Rz: 0.8 μm) Test time: 10 hr

[0051]

FIGS. 5 and 6 of the embodiment and the comparative example.
From the results of the performance test shown in the above, it is clear that the multilayer plain bearing of the present invention, which has an inorganic compound film layer formed on an aluminum alloy or copper alloy lining layer, has excellent seizure resistance and wear resistance. Yes, so it has excellent utility for plain bearings for automotive engines.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view of an embodiment of the multilayer plain bearing of the present invention.

FIG. 2 is an explanatory cross-sectional view of another embodiment of the multilayer plain bearing of the present invention.

FIG. 3 is an explanatory cross-sectional view of another embodiment of the multilayer plain bearing of the present invention.

FIG. 4 is an explanatory cross-sectional view of another embodiment of the multilayer plain bearing of the present invention.

FIG. 5 Examples 1 to 20 according to the present invention and Comparative Examples 1 to
4 is a graph showing a seizure test result of the plain bearing of No. 4.

FIG. 6 shows examples 1 to 20 and comparative examples 1 according to the present invention.
4 is a graph showing a wear test result of the plain bearing of No. 4.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base metal 2 ... Bearing alloy lining layer 3 ... Inorganic compound film layer 4 ... Lubricating layer made of soft metal or solid lubricant 5 ... Micro crack

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryosuke Kawagoe 1-15-1 Nihonbashi, Chuo-ku, Tokyo Inside Nippon Park Calling Co., Ltd. (72) Inventor Hirofumi Michioka 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor (72) Inventor Yoshio Fuwa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (4)

[Claims] 1. A multi-layer sliding bearing, wherein a substantially amorphous metal oxide or an inorganic compound film layer made of a water-insoluble or hardly water-soluble salt is formed on a lining layer made of a bearing alloy. . 2. A method according to claim 1, wherein a lining layer made of a bearing alloy is coated with a substantially amorphous or weakly crystalline metal oxide or an inorganic compound film layer made of a water-insoluble or poorly water-soluble salt, and a soft metal or a solid lubricant. A multi-layer plain bearing in which lubricating layers are laminated in any order. 3. The multilayer plain bearing according to claim 1, wherein the inorganic compound film layer has a microcrack. 4. The method according to claim 1, wherein the inorganic compound film layer comprises Mo, W, C
The multilayer plain bearing according to any one of claims 1 to 3, comprising at least one compound selected from r, Ti, and Zr.