JPH0693283A - Double-layered sliding member - Google Patents

Abstract

(57) [Summary] [Purpose] A multi-layer sliding member that exhibits excellent friction characteristics, in particular, excellent wear resistance characteristics, and also exhibits excellent cavitation resistance even when used under high-speed sliding conditions. provide. A multi-layer sliding member obtained by impregnating or coating a lubricating composition on a porous sintered metal layer formed on a steel backing, wherein the lubricating composition serves as a filler and is a fibrous magnesium oxalphate. , Fan-shaped magnesium oxysulfate or a mixture thereof in polytetrafluoroethylene containing 1 to 25% by weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer sliding member,
Specifically, the present invention relates to a multi-layer sliding member having a sliding surface provided with a lubricating composition containing polytetrafluoroethylene (hereinafter abbreviated as PTFE resin) as a main component. The multi-layer sliding member of the present invention exhibits excellent sliding characteristics in applications used in oil or under oil lubrication, such as guide bushes for shock absorbers and bearings for hydraulic pumps.

[0002]

2. Description of the Related Art Conventionally, PTFE resin has been widely used as a sliding member such as a bearing because it has excellent self-lubricating property, low friction coefficient, and excellent chemical resistance and heat resistance. . However, the sliding member made of only the PTFE resin is inferior in wear resistance and creep resistance. Therefore, depending on the use of the sliding member, for example, the drawbacks are solved by the following methods.

(1) A filler such as graphite, molybdenum disulfide or glass fiber is added to the PTFE resin. (2) A porous sintered metal layer integrally formed on a thin steel plate is impregnated with a PTFE resin using a solvent to cover the porous sintered metal layer.

Examples of the sliding member of the above aspect (2) include sliding members disclosed in Japanese Patent Publication No. 39-16950. That is, Japanese Patent Publication Sho 3
No. 9-16950 discloses a porous copper or copper alloy layer capable of having a steel backing and a matrix impregnated with polytetrafluoroethylene at least on its exposed surface. The polytetrafluoroethylene is mixed with lead or an oxide of lead, or both, and the mixture is at least less than 28% by volume of the matrix, and the amount of lead or lead and the lead oxide. Have proposed a bearing material of at least 16% in volume.

[0005]

However, although the above-mentioned conventional sliding member has a low coefficient of friction and exhibits excellent friction characteristics, it does not always satisfy wear resistance. Further, the conventional sliding member has a problem that cavitation occurs, the sliding surface is damaged, and abrasion is promoted, particularly when used in oil, especially under the condition of sliding at high speed. The present invention has been made in view of such circumstances, and an object thereof is to exhibit excellent friction characteristics, in particular, excellent wear resistance characteristics, and also excellent cavitation resistance even when used under high-speed sliding conditions. It is to provide a multi-layer sliding member that exhibits the properties.

[0006]

Means for Solving the Problems As a result of intensive studies by the present inventors, a lubricating composition obtained by adding a specific magnesium oxysulfate to polytetrafluoroethylene was porous sintered on a steel backing. It has been found that a multi-layer sliding member obtained by impregnating and coating a metal layer exhibits stable sliding characteristics with a very small amount of wear under the influence of cavitation even under high-speed sliding conditions.

The present invention has been completed based on the above findings, and the gist thereof is a multi-layered slide obtained by impregnating and coating a porous sintered metal layer formed on a steel backing metal with a lubricating composition. A dynamic member, wherein the lubricating composition comprises polytetrafluoroethylene containing 1 to 25% by weight of fibrous magnesium oxysulfate, fan-shaped magnesium oxysulfate or a mixture thereof as a filler. It exists in the sliding member.

The present invention will be described in detail below. In the multi-layer sliding member of the present invention, the back metal is made of a metal thin plate, and generally, a structural rolled steel thin plate is used, but other steel thin plates or metal thin plates other than steel may be used depending on the application of the sliding member. Alternatively, the metal thin plate may be plated with copper or the like to improve the corrosion resistance.

The porous sintered metal layer integrally formed on the back metal is formed of a copper alloy having excellent friction and wear characteristics such as bronze, lead bronze, phosphor bronze, etc. Other than this, for example, it may be formed from an aluminum alloy, iron, or the like. The sintered metal powder may have an irregular shape such as a spherical shape or a granular shape. The porosity of the porous sintered metal layer is 25% or more, preferably 28 to 35%. The sintered metal layer having such porosity is obtained by sintering a metal powder having a particle size that passes through an 80-mesh sieve but does not pass through a 350-mesh sieve.

In the multi-layer sliding member of the present invention, the PTFE resin which is the main component of the lubricating composition is mainly fine powder, for example, "Teflon 6CJ (trade name)" manufactured by Mitsui DuPont Fluorochemical Co., Daikin. "Polyflon F201 (trade name)" manufactured by Kogyo Co., Ltd., "Fluon CD-076" and "Fluon CD-12" manufactured by Asahi Glass Co., Ltd.
6 ”and“ Fluon CD-4 (trade name) ”are used.

A molding powder, for example, "Teflon 7AJ (trade name)" manufactured by Mitsui DuPont Fluorochemicals) is added to the above fine powder in an amount of 20% by weight or less based on the lubricating composition. it can. The amount of the PTFE resin in the lubricating composition is the remaining amount obtained by subtracting the amount of the filler from the amount of the lubricating composition, and is preferably 50 to 99% by weight, more preferably 65 to 85% by weight.

The magnesium oxysulfate used as the first filler for the PTFE resin as the main component of the lubricating composition is "MgSO ₄ .5MgO.8H ₂ O".
Alternatively, it is a basic magnesium sulfate hydrate represented by the chemical formula "MgSO ₄ .5Mg (OH) ₂ .3H ₂ O". Magnesium oxysulfate plays a role of compensating for the poor wear resistance of PTFE resin, a role of enhancing oil film retention in use in oil or under oil lubrication, and a role of enhancing cavitation resistance under high-speed sliding conditions and other fillers. Has the effect of improving the dispersibility of

In the multi-layer sliding member of the present invention, as the magnesium oxysulfate, fibrous ones and fan-shaped ones obtained by growing crystals into a fan-shaped bundle of acicular crystals are used. Regarding these magnesium oxysulfates, for example, “Functional Paper Research Journal” (No.
27, November (1988) pp. 26-31), "Fibrous magnesium compound" Mosheige "(registered trademark)". Can be done.

Among the above magnesium oxysulfates, fan-shaped magnesium oxysulfate is recommended in consideration of the dispersibility in PTFE resin and the formability in impregnating and coating the porous sintered metal layer with the lubricating composition. It

Since magnesium oxysulfate contains water of crystallization as can be seen from the above chemical formula, when it is blended as it is with a PTFE resin to form a lubricating composition, the lubricating composition is burned depending on the mixing ratio. At times, desorption of crystal water may occur and pinholes may be generated on the sliding surface due to the desorption of crystal water. The occurrence of this pinhole does not adversely affect the sliding characteristics,
Before the blending with the PTFE resin, magnesium oxysulfate is heat-treated at a temperature of 300 to 500 ° C. to remove the water of crystallization, because the adhesion of the lubricating composition to the sintered layer may decrease. Preferably.

In the present invention, the magnesium oxysulfate has a major axis diameter (length) of 1 to 1000 μm.
m, preferably 10 to 200 μm, a minor axis diameter (diameter) of 0.1 to 10 μm, preferably 0.1 to 1 μm, and an aspect ratio (major axis diameter / minor axis diameter) of 10 to 200, preferably 10 to 100. And fibrous magnesium oxysulfate having a length of 10 to 200 μm, preferably 5
It is preferable to use a fan-shaped magnesium oxysulfate of 0 to 200 μm. Specific examples of such fibrous magnesium oxysulfate and fan-shaped magnesium oxysulfate include "Mosheiji (trade name)" manufactured by Ube Industries.

In the present invention, the content of magnesium oxysulfate in the lubricating composition is 1 to 25% by weight,
It is preferably 10 to 15% by weight. Content is 1% by weight
If it is less than the above range, abrasion resistance, cavitation resistance and oil film retention are deteriorated, and if the content exceeds 25% by weight, moldability is deteriorated, which is not preferable.

In order to further improve the wear resistance and oil film retention of the lubricating composition comprising PTFE resin and magnesium oxysulfate, in addition to the above-mentioned first filler (magnesium oxysulfate), as a second filler, It is preferable to add at least one of magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium silicate, zinc oxide, zinc carbonate, zinc sulfide, calcium fluoride, sodium fluoride, mica fluoride and barium sulfate. Among these, magnesium oxide, magnesium silicate, magnesium hydroxide, fluoromica or zinc oxide are particularly preferable because they can further enhance the oil film retention of the lubricating composition.

The second filler has a property of adsorbing oil, and particularly when used in oil or under oil lubrication, by adsorbing oil on the sliding surface, the second filler can form an oil film on the sliding surface. It has the effect of enhancing the forming ability and the ability of retaining the oil film on the sliding surface. Therefore, by blending the second filler, a stable lubricating oil film is always formed on the sliding surface under oil lubrication, and excellent sliding characteristics are exhibited.

The average particle size of the second filler is usually 20 μm.
Hereinafter, the thickness is preferably 1 to 10 μm. The action and effect of the second filler begins to appear at 1 wt% formulation,
Is maintained until. However, when the amount is more than 20% by weight, the oil film forming ability and the oil film holding ability are maintained, but the moldability is adversely affected. Therefore,
The compounding ratio of the second filler is usually 20% by weight or less, preferably 1 to 15% by weight, more preferably 5 to 10% by weight.
However, the blending ratio of the second filler needs to be determined in consideration of the blending ratio of magnesium oxysulfate as the first filler.

That is, when the total content of the first filler and the second filler exceeds 30% by weight, the spreading property of the lubricating composition and the impregnating adherence to the porous sintered metal layer are obtained. Therefore, the total content of the first filler and the second filler is usually 30% by weight or less,
It is preferably 15 to 25% by weight.

In the present invention, the wear resistance and the lubrication composition comprising the PTFE resin and the first filler, or the lubrication composition comprising the PTFE resin, the first filler and the second filler, In order to improve the cavitation resistance, a fluororesin other than the PTFE resin can be further added.

Examples of the above-mentioned fluororesin include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE). , Polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF).

The mixing ratio of the fluororesin in the lubricating composition is
It is usually 30% by weight or less, preferably 0.1 to 20% by weight. If the blending ratio of the fluororesin exceeds 30% by weight, the sliding characteristics, particularly the friction coefficient, tends to increase, and the sliding stability may decrease, which is not preferable.

Further, in the present invention, a lubricating composition comprising a PTFE resin and a first filler, a PTFE resin,
In order to improve sliding stability and wear resistance with respect to a lubricating composition including the first filler and the second filler or a lubricating composition including each of these lubricating compositions and a fluororesin, Further, as the metal filler, at least one kind of lead, zinc, tin, copper and alloys thereof can be blended. The metal filler is used as a powder having an average particle size of 40 to 80 μm, and the mixing ratio thereof is 20% by weight or less, preferably 0.1 to 15% by weight.

In the present invention, in order to improve the abrasion resistance of the PTFE resin with respect to the above lubricating composition, other fillers generally used as fillers such as graphite, molybdenum disulfide and boron nitride are used. Solid lubricants such as 10% by weight or less may be blended, and other fillers generally used for the purpose of reinforcement, for example, carbon fiber, glass fiber, aramid fiber and other fiber reinforcements. May be blended in a proportion of 10% by weight or less.

Next, a method for manufacturing the multi-layer sliding member of the present invention will be described. First, the method for preparing the lubricating composition will be described. The lubricating composition can be obtained as a wet lubricating composition by a method in which a PTFE resin powder and each of the above-mentioned necessary fillers are pulverized and mixed, and then a petroleum solvent is added to the resulting mixture and the mixture is stirred. I can. The PTFE resin powder and the filler are pulverized and mixed at room temperature transition temperature (19 ° C.) or lower of the PTFE resin, preferably at a temperature of 10 to 18 ° C., and the resulting mixture and petroleum solvent are mixed by stirring. Is also performed at the same temperature as above. By adopting such a temperature condition, the fiberization of the PTFE resin is hindered and a uniform mixture can be obtained.

As the petroleum solvent, naphtha, toluene,
In addition to xylene, an aliphatic solvent or a mixed solvent of an aliphatic solvent and a naphthene solvent is used. The proportion of the petroleum solvent used is 100 for the mixture of PTFE resin powder and filler.
15 to 30 parts by weight relative to parts by weight. When the proportion of the petroleum solvent used is less than 15 parts by weight, the spreading property of the wet lubricating composition is poor in the impregnation coating process for the porous sintered metal layer described below, and as a result, the impregnation coating for the sintered layer is performed. Unevenness is likely to occur. On the other hand, when the proportion of the petroleum solvent used exceeds 30 parts by weight, not only the impregnation coating work becomes difficult, but also the uniformity of the coating thickness of the lubricating composition is impaired,
The adhesion strength between the lubricating composition and the sintered layer becomes poor.

Next, a method of manufacturing the multi-layer sliding member will be described. The multi-layer sliding member of the present invention has the following (a)-
It is manufactured through the step (d).

(A) A wet lubricating composition is sprinkled on the porous sintered metal layer formed on the backing metal and rolled by a roller to impregnate the wet lubricating composition with the wet lubricating composition and A uniform wet lubricating composition coating layer is formed on the surface. In this step, the wet lubricating composition is coated to a thickness of 2-2.5 times the coating thickness required for the final product. Most of the filling of the wet lubricating composition into the voids of the porous sintered metal layer proceeds in this step.

(B) The back metal treated in the steps (a) is 20
By holding in a drying oven heated to a temperature of 0 to 250 ° C. for several minutes, the petroleum-based solvent is scattered and removed, and then the dried lubricating composition layer is rolled to a predetermined thickness of 300 to 300 ° C. A pressure roller treatment is performed under a pressure of 600 kg / cm ² .

The backing metal treated in steps (c) and (b) is introduced into a heating furnace and heated at a temperature of 360 to 380 ° C. for several minutes to 10 minutes.
After heating for several minutes to perform firing, the product is taken out of the furnace and the dimensional variation is adjusted again by the roller treatment.

After cooling the back metal, the dimensions of which have been adjusted and adjusted in steps (d) and (c), a straightening roller treatment for correcting the undulations of the back metal is performed if necessary to obtain a desired multi-layer sliding member. To do.

In the multi-layer sliding member of the present invention, the thickness of the porous sintered metal layer is 0.1 to 0.35 mm, and the thickness of the sliding surface layer formed of the lubricating composition is 0.02 to 0.02. 0.15 mm
It is said that The multi-layer sliding member obtained as described above is cut into an appropriate size and used as a sliding plate in a flat plate state, and is also bent as a cylinder to be used as a cylindrical winding bush.

The multi-layer sliding member of the present invention has a sliding speed of 10 m.
/ Min, load 40 kgf / cm ² , thrust time test time 8 hours, friction coefficient 0.01-0.0
9, preferably 0.01 to 0.06, wear amount is 40 μm
The thickness is preferably 30 μm or less, more preferably 20 μm or less, and exhibits excellent sliding characteristics.

The multi-layer sliding member of the present invention has a sliding speed of 8.05 m / min, a load of 363.6 kgf / cm ² ,
In a hot (100 ° C.) oil (ATF-DII Idemitsu Petroleum) in a radial journal test with a test time of 5 hours, a friction coefficient of 0.010 to 0.020, preferably 0.010.
~ 0.015, wear amount is 40 μm or less, preferably 30
It is less than or equal to μm, more preferably less than or equal to 25 μm, and exhibits excellent sliding characteristics even under a high load.

Further, the multi-layer sliding member of the present invention has a sliding speed of 40 m / min, a load of 10 kgf / cm ² , and a test time of 8
In a thrust test of time, the amount of wear is 35 μm or less, it has excellent sliding characteristics even under high-speed sliding, and shows excellent cavitation resistance without peeling of the bearing surface.

[0038]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following examples, the sliding characteristics are determined by the following test methods (1) to (4).
The cavitation resistance was evaluated by the following (5) test method.

(1) Thrust test (A): The friction coefficient and the wear amount were measured under the conditions shown in Table 1. The coefficient of friction was shown as the variation value of the coefficient of friction from the start of the test for 1 hour to the end of the test, and the amount of wear was shown as the dimensional change of the sliding surface after 8 hours of the test time.

[0040]

[Table 1] Sliding speed 10 m / min Load 40 kgf / cm ² Test time 8 hours Lubrication ATF-DII (manufactured by Idemitsu Oil Co., Ltd.) Initial application of oil Mating material Carbon steel for machine structure (S45C)

(2) Thrust test (B): The amount of wear was measured under the conditions shown in Table 2. The amount of wear was shown by the amount of dimensional change of the sliding surface after the test time of 8 hours.

[0042]

[Table 2] Sliding speed 40 m / min Load 10 kgf / cm ² Test time 8 hours Lubrication ATF-DII (made by Idemitsu Petroleum Co., Ltd.) In oil Mating material Carbon steel for machine structure (S45C)

(3) Thrust test (C): The friction coefficient and the wear amount were measured under the conditions shown in Table 3. The coefficient of friction was shown as the variation value of the coefficient of friction from the start of the test for 1 hour to the end of the test, and the amount of wear was shown as the dimensional change of the sliding surface after 8 hours of the test time.

[0044]

[Table 3] Sliding speed 10 m / min Load 80 kgf / cm ² Test time 8 hours Lubrication ATF-DII (manufactured by Idemitsu Oil Co., Ltd.) Initial application of oil Stainless steel (SUS304)

(4) Radial journal test in high temperature oil: The friction coefficient and the wear amount were measured under the conditions shown in Table 4. The coefficient of friction was represented by the variation value of the coefficient of friction one hour after the test was started, and the amount of wear was represented by the dimensional change of the sliding surface after 5 hours of the test time.

[0046]

[Table 4] Sliding speed 8.05 m / min Load 363.6 kgf / cm ² Test time 5 hours Lubrication High temperature (100 ° C) ATF-DII (made by Idemitsu Petroleum) in oil Mating material Chromium molybdenum steel (SCM415H)

(5) Cavitation resistance: In the above thrust test (B), the peeled state of the surface of the test piece after 8 hours of test time was visually observed. The evaluation method is as shown in Table 5. It is desirable that the evaluation is good.

[0048]

[Table 5]

Examples 1 to 23 and Comparative Examples 1 to 3 In the following examples, as the PTFE resin, "Teflon 6CJ" (manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.) having an average particle diameter of 80 µm or less, and as a petroleum solvent, fat was used. A mixed solvent of a group solvent and a naphthene-based solvent (“Exsol”, a product of Exxon Chemical Co., Ltd.) was used.

First, the PTFE resin and the fillers shown in Table 6 were fed into a Henschel mixer and pulverized and mixed, and 20 parts by weight of a petroleum solvent was added to 100 parts by weight of the obtained mixed powder. The PTFE resin was mixed at a temperature below the room temperature transition point (15 ° C.) to obtain a wet lubricating lubricating composition.

The obtained wet lubricating composition was applied onto a porous sintered metal layer (thickness: 0.25 mm) formed on a steel backing (thickness: 0.70 mm) made of a thin metal plate, and wetted. The lubricating composition layer was rolled with a roller to a thickness of 0.25 mm to obtain a multilayer plate. The obtained multi-layer plate was held in a hot air drying oven heated to a temperature of 200 ° C. for 5 minutes to remove the solvent by scattering, and the dried lubricating composition layer was treated with a roller at a pressure of 400 kg / cm ² . Then, the thickness of the lubricating composition layer was set to 0.10 mm.

Next, the pressure-treated multi-layer plate is heated in a heating furnace at 37 ° C.
After heating and baking at 0 ° C. for 10 minutes, pressure treatment was performed again with a roller to adjust dimensions and correct waviness. Vertical 3
It was cut into 0 mm × width 30 mm to obtain a plate-like sliding member test piece having a thickness of 1.05 mm. The results of the thrust test (A) of each sliding member are shown in Tables 6-10. Tables 6 to 10
Inside, "MGO" is magnesium oxysulfate,
"Fiber" means fibrous magnesium oxysulfate,
“Fan-shaped” indicates a fan-shaped magnesium oxysulfate.

[0053]

[Table 6] ──────────────────────────────────── Example 1 2 3 4 5 PFTE ( (% By weight) 95 90 85 80 90 MGO (type) Fiber Fiber fan-shaped fan Fiber MGO (% by weight) 5 10 15 20 5 2nd filler (type) − − − − Mg CO ₃ 2nd filler (% by weight) − − − − 5 Fluororesin (kind) − − − − − Fluororesin (wt%) − − − − − Metal filler (kind) − − − − − Metal filler (wt%) − − − − − Coefficient of friction (× 10 ^-2 ) 2 to 4 2 to 5 3 to 6 3 to 6 3 to 7 Wear amount (μm) 30.6 32.7 36.8 31.3 28.4 ─────────────────── ─────────────────

[0054]

[Table 7] ──────────────────────────────────── Example 6 7 8 9 10 PFTE ( (% By weight) 85 85 80 75 70 MGO (type) Fiber Fan-shaped fiber Fan-shaped fan MGO (% by weight) 5 10 10 10 10 2nd filler (type) Mg (OH) ₂ MgO ZnO ZnS ZnO 2nd filler (wt%) ) 10 5 10 15 20 Fluororesin (kind) − − − − − Fluororesin (wt%) − − − − − Metal filler (kind) − − − − − Metal filler (wt%) − − − − − Friction coefficient (× 10 ^-2 ) 2 to 6 2 to 4 2 to 4 2 to 5 2 to 4 Wear amount (μm) 25.2 16.0 11.9 27.7 16.8 ───────────────── ────────────────────

[0055]

[Table 8] ──────────────────────────────────── Example 11 12 13 14 15 PFTE ( (% By weight) 80 70 75 70 75 MGO (type) fan-shaped fan-shaped fan-shaped fan-shaped MGO (% by weight) 15 15 20 20 10 2nd filler (type) ZnO ZnO ZnO ZnO BaSO ₄ 2nd filler (% by weight) 5 15 5 10 15 Fluororesin (type) − − − − − Fluororesin (wt%) − − − − − Metal filler (type) − − − − − Metal filler (wt%) − − − − − Coefficient of friction ( × 10 ^-2 ) 2 to 3 3 to 4 3 to 5 3 to 5 2 to 6 Wear amount (μm) 13.6 15.8 29.6 29.3 29.5 ──────────────────── ────────────────

[0056]

[Table 9] ──────────────────────────────────── Example 16 17 18 19 20 PFTE ( (% By weight) 80 75 75 65 90 MGO (type) fan-shaped fan-shaped fan-shaped fan-shaped MGO (% by weight) 10 5 5 5 10 2nd filler (type) CaF ₂ MgO MgO ZnO − 2nd filler (% by weight) 10 10 10 10 − Fluorine resin (type) − PFA − PFA − Fluorine resin (% by weight) − 10 − 10 − Metal filler (type) − − Pb Zn − Metal filler (% by weight) − − 10 10 − Friction coefficient ( × 10 ^-2 ) 3 to 8 2 to 4 2 to 4 3 to 6 2 to 4 Wear amount (μm) 28.7 18.4 23.3 22.7 32.6 ──────────────────── ────────────────

[0057]

[Table 10] ──────────────────────────────────── Actual Example Ratio Comparative Example 21 22 23 1 2 3 PFTE (wt%) 80 80 80 90 85 50 MGO ( type) fan fan fan - - - MGO (wt%) 10 10 10 - - - second filler (type) - - - ZnO BaSO ₄ - second Filler (wt%) − − − 10 15 − Fluororesin (type) PFA − PFA − − − Fluororesin (wt%) 10 − 5 − − − Metal filler (type) − Zn Zn − − Pb Metal filler (% By weight) − 10 5 − − 50 Friction coefficient (× 10 ⁻² ) 2 to 5 3 to 6 2 to 6 2 to 8 2 to 12 3 to 9 Wear amount (μm) 24.2 30.1 27.2 57.6 68.4 73.5 ─── ──────────────────────────────────

From the above test results, the sliding member test pieces of the examples of the present invention have stable performance with a low friction coefficient and excellent sliding characteristics with a very small amount of wear. It was a thing. On the other hand, the sliding member of the comparative example was inferior in sliding characteristics because the coefficient of friction was not very stable and the amount of wear was large.

Table 11 shows the results of the thrust test (B) and the cavitation resistance test of the sliding member test pieces of Examples 8 and 20.

[0060]

[Table 11]

From the above-mentioned test results, the sliding member test piece of the present invention has stable sliding characteristics with high cavitation resistance and extremely small wear amount without peeling under high-speed sliding conditions. Was.

Tables 12 and 13 show the results of the thrust test (C) of the sliding member test pieces of Examples 7, 8, 11, 17 and 18, and Comparative Example 3 and the radial journal test in high temperature oil.

[0063]

[Table 12] ──────────────────────────────────── Test piece Example 7 Example 8 Example Example 11 <Thrust test (C)> Friction coefficient (× 10 ^-2 ) 1 to 3 1 to 4 1 to 2 Wear amount (μm) 18.3 14.8 14.0 <Radial journal test> Friction coefficient (× 10 ^-2 ) 1.0 to 1.4 1.0 to 1.5 1.2 to 1.5 Wear amount (μm) 25 22 18 ───────────────────────────────────── ─

[0064]

[Table 13] ──────────────────────────────────── Test piece Example 17 Example 18 Comparison Example 3 <Thrust test (C)> Friction coefficient (× 10 ^-2 ) 1 to 3 ² to 4 3 to 9 Abrasion amount (μm) 19.7 25.5 76.0 <Radial journal test> Friction coefficient (× 10 ^-2 ) 1.0 to 1.2 1.0 to 2.0 1.2 to 7.7 Wear amount (μm) 28 38 85 ──────────────────────────────────── ─

From the above-mentioned test results, the sliding member test piece of the present invention showed stable performance with a low friction coefficient throughout the test time, and the amount of wear of the sliding member after the test was extremely small.

[0066]

As is apparent from the above-described examples, the multi-layer sliding member of the present invention has a porous composition in which a lubricating composition prepared by adding a specific magnesium oxysulfate to a PTFE resin is formed on a steel backing. By impregnating and coating the binder metal layer, it exhibits a low and stable friction coefficient under oil lubrication, particularly in high temperature oil, and exhibits excellent cavitation resistance even under extremely small wear and high speed sliding.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C10M 125: 22 125: 04 125: 10 125: 18 125: 26) C10N 10:02 10:04 10 : 08 20:06 B 8217-4H Z 8217-4H 30:06 40:02 50:08 (72) Inventor Sumihide Yanase 8 Kirihara Town, Fujisawa City, Kanagawa Prefecture OILES CORPORATION

Claims (8)

[Claims] 1. A multi-layer sliding member obtained by impregnating and coating a porous sintered metal layer formed on a steel backing metal with a lubricating composition, wherein the lubricating composition contains fibrous magnesium oxy as a filler. A multi-layer sliding member comprising polytetrafluoroethylene containing 1 to 25% by weight of a sulfate, a fan-shaped magnesium oxysulfate or a mixture thereof. 2. A lubricating composition comprising fibrous magnesium oxysulfate, fan-shaped magnesium oxysulfate or a mixture thereof as the first filler, and magnesium oxide, magnesium hydroxide, magnesium carbonate, silicic acid as the second filler. Magnesium, zinc oxide, zinc carbonate, zinc sulfide, calcium fluoride, sodium fluoride,
Consisting of polytetrafluoroethylene containing at least one selected from the group of fluoromica and barium sulfate, the content of the first filler is 1 to 25% by weight, and the content of the second filler is 1 to 20% by weight, and the total amount of both is less than 30% by weight. 3. The multi-layer sliding member according to claim 1, wherein the lubricating composition contains a fluororesin other than polytetrafluoroethylene in an amount of 30% by weight or less. 4. A lubricating composition comprising lead as a metal filler,
The multi-layer sliding member according to any one of claims 1 to 3, which contains 20% by weight or less of at least one selected from the group consisting of zinc, tin, copper and alloys thereof. 5. A fibrous magnesium oxysulfate having an average major axis diameter of 1 to 1000 μm and an average minor axis diameter of 0.1.
The multi-layer sliding member according to claim 1, having a thickness of 10 μm and an aspect ratio of 10 to 200. 6. The multilayer sliding member according to claim 1, wherein the fan-shaped magnesium oxysulfate has an average length of 10 to 200 μm. 7. The multilayer sliding member according to claim 2, wherein the second filler has an average particle diameter of 20 μm or less. 8. The average particle diameter of the metal filler is 40 to 80 μm.
The multilayer slide member according to claim 4, wherein