US3507775A - Lubricant producing system - Google Patents

Lubricant producing system Download PDF

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US3507775A
US3507775A US740879A US3507775DA US3507775A US 3507775 A US3507775 A US 3507775A US 740879 A US740879 A US 740879A US 3507775D A US3507775D A US 3507775DA US 3507775 A US3507775 A US 3507775A
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atom percent
alloy
percent
molybdenum
atom
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Ernest J Breton
Robert E Murvine
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Stoody Co
EIDP Inc
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EI Du Pont de Nemours and Co
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/02—Parts of sliding-contact bearings
    • F16C33/04—Brasses; Bushes; Linings
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C19/00—Alloys based on nickel or cobalt
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02G—HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINE PLANTS; USE OF WASTE HEAT OF COMBUSTION ENGINES; NOT OTHERWISE PROVIDED FOR
    • F02G1/00—Hot gas positive-displacement engine plants
    • F02G1/04—Hot gas positive-displacement engine plants of closed-cycle type
    • F02G1/043—Hot gas positive-displacement engine plants of closed-cycle type the engine being operated by expansion and contraction of a mass of working gas which is heated and cooled in one of a plurality of constantly communicating expansible chambers, e.g. Stirling cycle type engines
    • F02G1/0435—Hot gas positive-displacement engine plants of closed-cycle type the engine being operated by expansion and contraction of a mass of working gas which is heated and cooled in one of a plurality of constantly communicating expansible chambers, e.g. Stirling cycle type engines the engine being of the free piston type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/027—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle four

Definitions

  • the lubricant can be formed in situ from the fluid used
  • one surface is of an alloy containing at least 6 atom percent of an element selected from the group consisting of molybdenum and tungsten, at least 10 percent by volume of the alloy being an intermetallic compound of molybdenum or tungsten having a Vickers Hardness number of 550-1800;
  • the mating surface is either of an alloy containing at least 50 atom percent iron, at least 1 atom percent carbon, at least one-half the weight of the remainder of the alloy being composed of at least one of the following elements: chromium, manganese, molybdenum and tungsten, said element(s) being present as carbide(s) or in a fully hardened solid solution, and having a Vickers Hardness number of at least 400 or a similar alloy containing at least 80 atom percent iron and having a Vickers Hardness number of at least 200 or an alloy of 11-15 atom percent carbon, 1.5-3 atom percent silicon, the balance being iron, having a Vickers Hardness
  • This invention is in the field of functional systems producing lubrication.
  • a lubricant for the interface of relatively movable (sliding, rubbing, rolling, etc.) opposing surfaces should serve to completely separate those surfaces. This condition is known as full-film or hydrodynamic lubrication. Full-film lubrication physically separates the two sliding surfaces by a relatively thick continuous film of self-pressurized lubricant with no metal-to-metal contact. Technologically, this is the preferred kind of lubrication since it offers the lowest coefficient of friction and the smallest amount of wear.
  • a transitional zone known as mixed-film lubrication is a combination of hydrodynamic and boundary lubrication. Under this condition, part of the total load applied to an opposing metal surface is supported by individual loadcarrying areas of self-pressurized lubricant and the remaining part by the very thin film associated with 'boundary lubrication.
  • the coeflicient of fluid friction is approximately proportional to viscosity and speed and inversely proportional to load.
  • the coefficient of friction is independent of viscosity and rubbing speed.
  • ZN/p where Z is the viscosity of the input fluid, N is rotational speed and p is bearing pressure (load)
  • the coefficient of friction remains essentially constant.
  • Evidence indicates that in this zone a combination of fluid friction and boundary lubrication exists, i.e., mixed-film lubrication.
  • Lubrication of the opposing surfaces of seals, gears, bearings and pistons therefore, has required the use of more viscous materials such as hydrocarbon oils, synthetic oils and greases.
  • These lubricants in addition to being incapable of being tolerated in certain applications because of process contamination, possess other disadvantages.
  • Sludges tend to form in the lubricants as a result of oxidation, polymerization, or other causes. These sludges reduce the lubricating qualities of the lubricant and often cause sticking of relatively moving parts.
  • organic acids tend to form in the lubricant during use thereof, apparently because of oxidation of the oil at the elevated temperatures to which the oil is exposed, and organic acids cause corrosion.
  • the object of this invention to provide assemblies composed of rolling element bearings, seals, sliding vanes, pistons, pistonrings, gears, etc. moving against opposing surfaces that will function in the presence of low viscosity organic agents. It is another object to provide an assembly capable of converting in situ a low viscosity organic fluid, e.g., gasoline vapor or liquid, unsuitable as a lubricant in its unpolymerized state to a more viscous polymeric material characterized by its ability to maintain a state of boundary lubrication or fullfilm lubrication during periods of operation. It is a further object to provide lubricant-producing assemblies for designing and constructing devices (engines, pumps, etc.) in which the problems resulting from the conventional use of lubricants are eliminated.
  • a low viscosity organic fluid e.g., gasoline vapor or liquid
  • an assembly comprising at least two members having relatively movable opposing surfaces, members A and B, and a fluid capable of polymerizing to form a lubricant during operation of the assembly (a lubricant precursor);
  • the metal-opposing surface of member A comprising an alloy selected from the group consisting of (a) an alloy of 11-15 atom percent carbon, 1.5-3 atom percent silicon and the balance being substantially all iron, and having a Vickers Hardness number of at least 150, (b) 1 an alloy of at least 80 atom percent iron and having a Vickers Hardness number of at least 200, and (c) 1 an alloy of at least 50 atom per cent (50-79 atom percent) iron and having a Vickers Hardness number of at least 400, preferably the alloy of (a) or (b); the metal-opposing surface of member B comprising an alloy of at least 6, preferably at least 12, atom percent of an element selected from the group consisting of molybdenum and tungsten
  • assemblies of this invention can be formed that meet the criteria set forth in the previous paragraph where one of the relatively movable opposing surfaces comprises an alloy of 6-85, preferably 19-25 atom percent molybdenum, 4-56, preferably 4-22 atom percent silicon and the balance essentially 10-90 atom percent of an element selected from the group consisting of iron, cobalt and nickel, preferably 53-77 atom percent cobalt; the other of the relatively movable opposing surfaces comprising an alloy of l-7 atom percent carbon, up to 13 atom percent chromium and the balance essentially 80-98 atom percent iron; and the fluid selected from the previously stated group but being preferably gasoline.
  • the first-mentioned relatively movable opposing surface comprises an alloy of tungsten, it may be diflicult to incorporate more than 25 atom percent of tungsten into the alloy because of the high melting point of tungsten.
  • Coefficient of dry friction is measured in air, as follows:
  • the substantially flat metal-contacting surface of the member having the lower Vickers Hardness number (usually member B) is given a metallographic polish and washed with acetone to insure a smooth clean surface.
  • a -inch ball (or, alternatively, an object having a spherical surface radius of -inch) near its point of contact with the flat surface, composed of the material of the harder member (usually member A) is cleaned by polishing with 600 grit emery cloth.
  • the testsample of the flat member is mounted on a moving track and passed at a speed of 0.001 cm./sec. in contact with the ball of the second member.
  • a load of 1000 grams is imposed on the ball.
  • the frictional drag created by the sample of the flat member moving in contact with the ball is measured by a tangential strain gauge.
  • the value of dry friction is the tangential force required to move the test sample divided by the normal force, which in this case is 1000 grams.
  • the important criteria for selecting this alloy are in three distinct areas: chemical composition; physical structure; and physical characteristics.
  • chemical composition the alloy should contain at least 6 atom percent of molybdenum or tungsten.
  • physical structure it should be composed of at least 10 percent by volume of an intermetallic compound having molybdenum or tungsten as a component.
  • the physical characteristics should be such that the alloy has a coeflicient of dry friction when contacted against the mating surface of no greater than 0.25; the intermetallic compound of the alloy has a Vickers Hardness number ranging between 550 and 1800; and, when present, the matrix containing the intermetallic compound should have a Vickers Hardness number less than that of the intermetallic compound.
  • the aforementioned alloys When used in the present invention, the aforementioned alloys will be capable of producing lubricant when subjected to sliding action in the presence of a fluid capable of being converted into a material having lubricating properties. Specifically, when subjected to 50,000 PV (load in p.s.i. velocity of 180 ft./min. or greater) in the wear tester shown in FIGURE 1, the total wear of both lubricant producing alloy (sample) and mating surface (reference ring) will be less than 4.0 mils/ hrs. as measured by micrometer or weight measurements; and the coefficient of friction will be less than 0.2.
  • PV load in p.s.i. velocity of 180 ft./min. or greater
  • test procedure was designed so that operating conditions would lead to a state of lubrication below that of the full-fluid range, thus obtaining metalto-metal interaction. In this way, the compatibility and ability of the metal combinations to produce lubricant can be measured. It is believed that the lubricant i not produced continuously in the system of the invention. Instead, additional lubricant is only produced after that originally formed is used.
  • FIGURE 1 is a schematic representation of the Wear tester utilized in determining wear performance. It is representative of end thrust type bearings and is useful as a screening device for determining systems of the present invention.
  • the specimen of number A to be tested 12 is rotated by a DC motor 10.
  • the friction between the ring of member B11 and the test specimen of member A 12 produces a torque in the shaft 13.
  • the shaft 13 is constrained from turning by the lever arm 14 connected to a strain gauge 15.
  • the strain gauge voltage is continuously monitored on a recorder. This voltage is converted into pounds pull by previous calibration. From the geometry of the system, the tangential force on the specimen is calculated. The coefficient of friction equals the tangential force divided by the normal thrust of load pushing the specimen and wear ring together.
  • Wear rates are deter mined from weight loss and also by micrometer measurements. Tests are carried out by rotating the test specimen at a speed of 180 ft./min. and at'varying loads. The PV is determined by multiplying the load in p.s.i. based upon actual contact area by the speed in ft./min.
  • the specimen 12 and the ring 11 are machine ground to obtain parallel faces and then hand lapped on 400 grit paper; vacuum dried at 100 C. for at least 1 hour; and then weighed to 0.0001 gram and measured to 0.0001 inch. They are then mounted in the tester as shown in FIGURE 1 and the cup 16 filled with gasoline or other fluid 17.
  • the cup 16 is lined with cooling coils to minimize evaporation.
  • the tester is run at 650 rpm. (to provide 180 ft./min.) for 1 to 2 minutes. After this 6 run minutes at each weight increment until failure occurs.
  • Example 1-10 The test specimens were prepared from the elements set forth in Tables I-A and LB by mixing, melting and casting them into buttons 1% inches in diameter and inch thick. The buttons were machined to fit the wear tester shown in FIGURE 1. All except the composition of Example 7 were tested using Elastuf 44 steel 2 composed of 2.1 atom percent carbon, 1 atom percent chr0- mium, 0.3 atom percent molybdenum, 0.4 atom percent silicon, 0.9 atom percent sulfur and the balance, 93.6 atom percent, iron as the ring; and liquid gasoline as the fluid. In Example 7, the ring was composed of an alloy of 95.7 atom percent iron and 4.3 atom percent carbon hardened to a Vickers Hardnes number of 510.
  • the preselected load is applied and the test is run continuously for 18 to 20 hours. Due to evaporation, additional fuel must be added evry 4 to 6 hours. After 18 to 20 hours, the specimen 12 and the ring 11 are again vacuum dried; weighed; and measured. Alternatievly, the tester may be loaded in increments of.20 lbs. while being run at the previously disclosed speed. The tester may be 75 Examples 11-14 In the examples, tungsten was used in place of molybdenum. The test specimens were prepared and tested following the procedure set forth in Examples 1-10. The results obtained are compared to the results obtained with four controls in Table II.
  • Interrnetallic compounds found in the alloys operable in this invention include (1) the topological close packed (TCP) structures including the sigma, Chi, Mu and Laves phases, (2) the semi-carbides of the M C and M C type and (3) MoSi type.
  • TCP topological close packed
  • the presence and amount of intermetallic compounds may be determined by either X-ray diffraction or metallographic analysis. For example, in Example 6 (Co/Mo/Si77/ 19/4) there is present 20 volume percent Laves phase, an intermetallic compound.
  • Example 9 is a pure intermetallic compound (MoSi with no matrix.
  • these alloys are defined in this patent as consisting essentially of a substantial amount of at least one metal A and asubstantial amount of at least one metal B, and silicon, metal A being selected from the group consisting of molybdenum and tungsten and metal B being selected from the group consisting of .cobalt and nickel; the sum of the amounts of metals A and B'being at least 60 atom percent of the alloy; the amount of silicon and the relative amounts of metals A and B being such as to provide -85 volume percent of said alloy in the Laves phase; the Laves phase being distributed in a relatively soft matrix of the remaining 7015 volume percent of said alloy. 1
  • Example 2 The critical necessity for having the requisite amoun of intermetallic compound present may be dramatically shown by comparing Example 2 with Control E. In both alloys, 9 atom percent of molybdenum is presentwith iron as the major constituent. In the case of an acceptable alloy in Example 2, however, 10 atom percent of silicon is also present. The silicon, which along with vanadium,
  • izer of intermetallic compounds in metal alloys forms a ternary intermetallic compound in excess of 10 volume percent.
  • the binary iron-molybdenum alloy in the, atomic ratios shown in Controls B and C doesnot have the requisite amount of an intermetallic compound.
  • Comparison of the data obtained shows that the binary alloy of the Controls produces a high dry friction coefiicient and seizes against the mating surface in the wear tester, while the ternary compound in Example 2, although containing a like amount of molybdenum, is a satisfactory lubricant producing alloy.
  • Tungsten carbide which is classified as an intermetallic compound by the present definition, does not operate in the present invention. Although this material displays an extremely high wear resistance,'it also is characterized by a Vickers Hardness number in excess of 2500. This hardness results in excessive wear of the mating material (member A) rather than lubrication.
  • Controls G and I which are Hastelloy B and C, respectively, and Control D are similar in chemical composition to the operable compositions of this invention.
  • Hastelloy B and C are designed for corrosion resistance
  • Control D is designed for high temperature operation, the molybdenum and tungsten are maintained in solution in the matrix phase rather than in compounds.
  • the formation of molybdenum or tungsten compounds e.g., Laves or sigma phases, tends to accelerate corrosion and, as discussed by Simms in Journal of Metals, October 1966, pp. 1119-4130, the-formation of these compounds is undesirable for high temperature application. Without the formation of intermetallic compounds, these materials do. not function in the present'invention.
  • MATING'SURFACE J The important criteria for selecting the material for the mating surface of member A are in' two distinctages: chemical composition" and physical characteristicsfThe particular materials may 'bedivided into three groups, the first two being preferred. V v
  • the first group embraces the cast irons containing .graphite They are the gray cast irons and malleable cast ironsqCarbon content varies from 11 to 15 atom'percent, and silicon content from 1.5 to 3"atom 'percentwithjthe balance being' iron and trace amountsof othermetals. Hardnesses can be as low as Vickers Hardness numbers of 150. It is believed that the presence of.the carbon as graphite oflsets the effect of softness. These alloys are useful as piston rings, cylinder walls and in other applications having poor lubrication.
  • the second group consists of iron alloys containing at least 80 atom percent iron, at least 1 atom percent carbon and having Vickers Hardnes numbers of at least 200.
  • This group embraces the white cast irons, carbon steels, most of the tool steels and the bottom of the range of martensitic stainless steels. It is preferred that the Examples 21-23
  • the test specimens were prepared and tested following the procedure set forth in Examples 1-10.
  • the alloy of Example 6 was used; namely, 77 atom percent cobalt, l9 atom percent molybdenum and 4 atom percent silicon. The results obtained are compared to the results obtained with two controls in Table IV.
  • I Also contained 0.3 atom percent molybdenum, 0.4 atom percent; silicon, 0.9 atom percent manganese and 1.7 atom percent sulfur.
  • Vickers Hardness number of the steels in this group be over 270.
  • the third group consists of iron-base alloys containing 50-79 atom percent iron, at least 1 atom percent carbon and having Vickers Hardness numbers of at least 400. Also undesirable are the ferritic stainless steels and most of the austenitic stainless steels. However, it maybe possible to use work hardened low nickel alloys of austenitic stainless steels.
  • the major alloying elements for the second and third groups are chromium, manganese, molybdenum and tungsten. These elements should represent at least one-half of the weight of the remaining alloying elements (besides iron and carbon) and should be present primarily as carbide precipitates or in a fully hardened solid solution, e.g., the martensite phase of iron. Nickel and cobalt are undesirable and their sum in the alloy should be less than 6 atom percent.
  • Example 15-20 The test specimens were prepared and tested following the procedure set forth in Examples l-lO.
  • the alloy of Example 7 was used; namely 56 atom percent cobalt, 22 atom percent molybdenum and 22 atom percent silicon.
  • the results obtained are compared to the results obtained with four controls in Table From the foregoing examples and controls, the necessity for a minimum Vickers Hardness Number of 200 when at least atom percent iron is present in the mating surface will be apparent.
  • Controls B-F when contrasted to Examples 18 and 19, bring out the importance of the minimum content of iron in the surface. The failure of relatively soft materials is illustrated in Control A.
  • ENVIRONMENTAL MEDIUM The most impressive feature of the system of this invention is its ability to polymerize certain fluids to form lubricants in situ, thereby obviating the necessity of using an extraneous (non-essential to the function of the system) material such as heavy petroleum products (e.g., motor oils, lubes, and greases).
  • heavy petroleum products e.g., motor oils, lubes, and greases.
  • the invention is concerned primarily with systems involving petroleum hydrocarbon fuels as the environmental medium.
  • petroleum hydrocarbon fuels as the environmental medium.
  • gasoline in automotive, marine, and aircraft engines; kerosene and jet fuels in modern jet aircraft; and diesel fuels in diesel type engines are particularly useful in this invention.
  • These fluids may be classified as petroleum hydrocarbons whose terminal boiling points are no greater than 345 C.
  • Examples 1-23 gasoline was used as the environmental medium, gasoline being representative of petroleum hydrocarbons having a terminal boiling point no greater than 345 C.
  • Examples 24-30 other fluids of lesser commercial interest were tested following the procedure set forth in the previous examples.
  • the combination of alloys used in Examples 11 7 and 15 were used; namely, 5 6 atom percent cobalt, 22
  • the use of the systems of this invention make it possible to use hydraulic fluids of relatively low viscosity.
  • the viscosity of the lubricants produced from these fluids is high enough to perform a lubricating function.
  • the viscosity of the hydraulic fluid is low enough so that no heating is required to maintain fluidity as is usually necessary with more viscous fluids.
  • One method to achieve the results of the present invention is to spray gasoline vapor into the chamber containing the relatively movable opposing surfaces.
  • FIGURE 2 illustrates a device utilized to test the efficiency of certain type bearings intended for commercial applications.
  • friction between shaft 21 and the bearing to be tested 22 causes a yolk 23 to rotate when a load 24 is applied.
  • the rotation of the yolk applies a force to a torque transducer 25 through lever arm 26.
  • the tangential force acting at the bearing shaft interface is calculated. This divided by the load applied gives the coeflicient of friction.
  • the transducer is calibrated before each test.
  • the process fluid in this case gasoline, is introduced into the bearing system through port 27.
  • test procedure involves increasing the flow of gasoline to 1 lb. per hour, at no load and then increasing the r.p.m. of the shaft to the desired level.
  • the load is applied in increments of 20 lb. and the apparatus allowed to run from minutes to an hour at each step.
  • roller bearings inner and outer races
  • journal bearings in Example 32
  • Example 31 Inner and outer races for roller bearings were made by centrifugally castingan alloy of 77 atom percent cobalt, 19 atom percent molybdenum and 4 atom percent silicon to nominal dimensions. The final tolerances were obtained by grinding.
  • roller bearing test was carried out by'nsing -the cast inner and outer races and commercially available rollersof hardened steel (SAE 52100)
  • Thenominal inside diameter of'the outer race was 0.901 inch and the outside diameter of the inner race was 0.742inch.
  • the rollers were 0.078 inch in diameter and 0.612 inch long.
  • Table VIJAs can be seen from the table, the steel-steel roller bearing system failed at 3600 r.p.m. at a'load' of 600 lbs'.; while the system of Example 31 wasstill operating efliciently at a load of 1000 lbs. Additionally can be seen, that even at' smaller loads, the coelficient'of friction in the system of Example 31 is significantly less than that of the steel races.
  • Example 32 Journal bearings were fabricated by centrifugally casting an alloy of 56 atom percent cobalt, 22 atom percent molybdenum and 22 atom percent silicon.
  • the norminal size of the journal bearings was 0.752 inch and the shaft of hardened steel (SAE 52100) was 2 mils undersize' to give the recommended clearance'for this size bearing.
  • the journals were rough machined used carbide tools to within 10 mils of final tolerances and then ground the rest of the way.
  • the bronze bearing seized at the first increment of loading.
  • the cast CoMoSi bearing was loaded to a PV of 100,000 with no seizure.
  • Elastutt 44 93.6 atom percent Fe 2.1 atom percent C; 1 atom percent Cr; 0.9 atom percent S; 0.4, atom percent St; 0.3 atom percent Mo.
  • the assemblies of this invention find applicability in all types of engines: 2- and 4-cycle reciprocating engines; 2- and 4-cycle rotary engines including the epitrochoidal, elliptical, wedge and vane piston types; free piston gas generating engines; turbo-jet engines; standard jet engines; and gas turbine engines.
  • the bearing surfaces and seals can be composed of or coated with alloy of molybdenum or tungsten referred to herein as the member B alloy; while the opposing surfaces including the crankshaft, the piston cylinder wall, etc. can be composed of the alloy of iron referred to herein as the member A alloy.
  • the members B alloy can be used as a surface coating for the plunger which slides through a chamber made of member A, or member B can be used as a coating for the cylinder chamber through which a plunger made of or coated with member A slides.
  • the vanes can be coated with or composed of the member B alloy which makes contact with a chamber of member A, or visa versa. This permits operation with low viscosity fuels such as gasoline or kerosene. This opens up the possibility of operating' diesel engines with less viscous fuels than are now used.
  • a particularly interesting application of the present invention is in the rotary internal combustion engine described in US. Patent 3,359,953.
  • This patent describes special techniques to overcome the side sealing problem.
  • a coating of member B alloy of the present invention has been used on the contacting surface of the ring seals in the side seal assembly of such a rotary engine while contacting end walls composed of member A alloy. It is apparent that the member B alloy of the assembly of the present invention would be useful as the contacting surface of all the end face seals while the inner surface of the end walls was composed of the member A alloy.
  • Another interesting application of the present invention is as a solution to the problem of increasing the load bearing capacity of oil impregnated porous bearings, i.e., selflubricating bearings. Relatively large pores are needed in these bearings to transmit the relatively viscous lubricant, thereby reducing load bearing capacity.
  • a low viscosity precursor that forms a high viscosity lubricant in situ on thebearing surface smaller pores would be used. This, in turn, increases the load bearing capacity of the bearing.
  • greases having greater viscosity than conventional oils are produced with an accompanying increase in load bearing capacity.
  • the assemblies of this invention will be useful in a multitude of situations involving the use of bearings, gears, seals and pistons, the members of the assemblies being used either to form the parts or as coatings "CM 7028: 77 atom percent Co; 19 atom percent Mo; 4 atom percent Si.
  • AISI 1090 95 atom percent Fe; 4.1 atom percent C; 0.7 atom percent Mn 0.1 atom percent 1? 0.1 atom percent S.
  • a system comprising an assembly of at least two members, members A and B, having relatively movable opposing surfaces and an environmental fluid capable of forming a lubricating medium for said opposing surfaces during operation of the assembly; the Opposing surface of member A consisting essentially of an alloy selected from the group consisting of (a) an alloy of 11-15 atom percent carbon, l.5-3 atom percent silicon and the balance being substantially all iron, and having a Vickers Hardness number of at least 150 (b) an alloy of at least 80 atom percent iron, at least 1 atom percent carbon, and having a Vickers Hardness number of at least 200, and (c) an alloy of 50-79 atom percent iron, at least 1 atom percent carbon, and having a Vickers Hardness number of at least 400, the sum of any cobalt and nickel in said alloys (b) and (c) being less than 6 atom percent, at least one-half of the weight of the remainder of alloys (b) and being selected from the group of elements consisting of chromium, molybden
  • a system as in claim 1 wherein said opposing surface of member A is an alloy of 11-15 atom percent carbon, 1.5-3 atom percent silicon, the balance being substantially all iron, having a Vickers Hardness number of at least 150.
  • a system as in claim 1 wherein said opposing surface of member A is said alloy of at least 80 atom percent iron having a Vickers Hardness number of at least 4.
  • a system as in claim 1 wherein said opposing surface of member B consists essentially of an alloy of at least 12 atom percent of an element selected from the group consisting of molybdenum and tungsten.
  • said opposing surface of member B consists essentially of an alloy of 6-85 atom percent molybdenum, 4-5 6 atom percent silicon, the bal- 16 ance being selected from the group consisting of iron, cobalt and nickel.
  • a system as in claim 1 wherein said opposing surface of member B consists essentially of an alloy of 19-25 atom percent molybdenum, 4-22 atom percent silicon and 53-77 atom percent cobalt.
  • a system as in claim 1 wherein said environmental fluid is a petroleum hydrocarbon having a terminal boiling point no greater than 345 C.
  • a system as in claim 1 wherein said environmental fluid is gasoline.
  • An assembly comprising at least two members, members A and B, having relatively movable opposing surfaces; the opposing surface of member A consisting essentially of an alloy selected from the group consisting of (a) an alloy of 11-15 atom percent carbon, 1.5-3 atom percent silicon and the balance being substantially all iron, and having a Vickers Hardness number of at least 150, (b) an alloy of at least atom percent iron and having a Vickers Hardness number of at least 200, and (c) an alloy of at least 50 atom percent iron and having a Vickers Hardness number of at least 400, the sum of any cobalt and nickel in said alloys (b) and (c) being less than 6 atom percent, at least one-half of the weight of the remainder of alloys (b) and (c) being selected from the group of elements consisting of chromium, molybdenum, manganese and tungsten, said element(s) being present as carbide(s) or in a fully hardened solid solution; and the opposing surface of member B consisting essentially of an
  • an assembly as in claim 13 wherein said opposing surface of member A is said alloy of at least 80 atom percent iron having a Vickers Hardness number of at least 16.
  • An assembly as in claim 13 wherein said opposing surface of member B consists essentially of an alloy of at least 12 atom percent of an element selected from the group consisting of molybdenum and tungsten.
  • a process for forming a lubricating medium which comprises placing the surfaces of at least two members, members A and B, in opposition, the opposing surface of member A consisting essentially of an alloy selected from the group consisting of (a) an alloy of 11-15 atom percent, 1.5-3 atom percent silicon, the balance being substantially all iron, having a Vickers Hardness number of at least 150, (b) an alloy of at least 80 atom percent iron and having a Vickers Hardness number of at least 175, and (c) an alloy of at least 50 atom percent iron and having a Vickers Hardness number of at least 400, the sum of any cobalt and nickel in said alloys (b) and (c) being less than 6 atom percent, at least one-half of the Weight of the remainder of alloys (b) and (c) being selected from the group of elements consisting of chromium, molybdenum, manganese and tungsten, said element(s) being present as carbide(s) or in a fully hardened solid solution; and the opposing suface
  • the improvement wherein the opposing surface of member A consists essentially of an alloy selected from the group consisting of (a) an alloy of 11-15 atom percent carbon,

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Lubricants (AREA)
  • Sliding-Contact Bearings (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)
US740879A 1968-06-28 1968-06-28 Lubricant producing system Expired - Lifetime US3507775A (en)

Applications Claiming Priority (1)

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US74087968A 1968-06-28 1968-06-28

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US740879A Expired - Lifetime US3507775A (en) 1968-06-28 1968-06-28 Lubricant producing system

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US (1) US3507775A (fr)
JP (1) JPS5019700B1 (fr)
AT (2) AT309649B (fr)
BE (1) BE735273A (fr)
BR (1) BR6910291D0 (fr)
CH (1) CH528042A (fr)
DE (1) DE1932736C3 (fr)
ES (1) ES368849A1 (fr)
FR (1) FR2016781A1 (fr)
GB (1) GB1275455A (fr)
IL (1) IL32488A (fr)
LU (1) LU58952A1 (fr)
NL (1) NL167505C (fr)
NO (1) NO127976B (fr)
SE (1) SE366058B (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4033728A (en) * 1974-11-11 1977-07-05 Nissho-Iwai Co., Ltd. Synthetic caking coal and method for production thereof
US6948922B2 (en) * 1998-10-05 2005-09-27 Matsushita Electric Industrial Co., Ltd. Hermetic compressor and open compressor
US20090018578A1 (en) * 2004-09-13 2009-01-15 Wound Care Technologies, Llc, Wound closure product

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2238864A (en) * 1939-09-15 1941-04-15 Socony Vacuum Oil Co Inc Processing equipment
US2239501A (en) * 1941-04-22 Lubricants containing polymers of
US2673175A (en) * 1954-03-23 Synthetic lubricating oil
US3194759A (en) * 1962-10-31 1965-07-13 Martin J Devine Lubricated bearing assembly
US3217834A (en) * 1962-06-22 1965-11-16 Nakamura Kenichi Process of lubrication for metal frictional surfaces
US3283029A (en) * 1962-09-26 1966-11-01 Raffinage Cie Francaise Hydraulic fluids

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2239501A (en) * 1941-04-22 Lubricants containing polymers of
US2673175A (en) * 1954-03-23 Synthetic lubricating oil
US2238864A (en) * 1939-09-15 1941-04-15 Socony Vacuum Oil Co Inc Processing equipment
US3217834A (en) * 1962-06-22 1965-11-16 Nakamura Kenichi Process of lubrication for metal frictional surfaces
US3283029A (en) * 1962-09-26 1966-11-01 Raffinage Cie Francaise Hydraulic fluids
US3194759A (en) * 1962-10-31 1965-07-13 Martin J Devine Lubricated bearing assembly

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4033728A (en) * 1974-11-11 1977-07-05 Nissho-Iwai Co., Ltd. Synthetic caking coal and method for production thereof
US6948922B2 (en) * 1998-10-05 2005-09-27 Matsushita Electric Industrial Co., Ltd. Hermetic compressor and open compressor
US20090018578A1 (en) * 2004-09-13 2009-01-15 Wound Care Technologies, Llc, Wound closure product

Also Published As

Publication number Publication date
BR6910291D0 (pt) 1973-01-04
DE1932736C3 (de) 1974-06-20
NO127976B (fr) 1973-09-10
GB1275455A (en) 1972-05-24
NL167505C (nl) 1981-12-16
IL32488A0 (en) 1969-08-27
ES368849A1 (es) 1971-07-16
BE735273A (fr) 1969-12-01
JPS5019700B1 (fr) 1975-07-09
IL32488A (en) 1972-07-26
DE1932736B2 (de) 1973-11-08
NL167505B (nl) 1981-07-16
CH528042A (de) 1972-09-15
FR2016781A1 (fr) 1970-05-15
AT309649B (de) 1973-08-27
AT309646B (de) 1973-08-27
SE366058B (fr) 1974-04-08
NL6909954A (fr) 1969-12-30
DE1932736A1 (de) 1970-01-02
LU58952A1 (fr) 1969-11-12

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