摘要:
A low-friction piston construction for use in an oil-fed cylinder bore with the piston skirt relieved to define lands that are coated with SFL (graphite, MoS.sub.2, BN, and a special expoxy resin). A method of making such piston construction including provision of asperities on the skirt wall onto which the SFL coating is thermally sprayed and formation of small pockets at the mouth of the asperities to additionally act as oil replenishing reservoirs. A method of using such piston construction in an engine which comprises provisions of a slightly increased gap between the piston and cylinder wall and formation of a transferred SFL coating from the piston to the cylinder wall resulting in two polished microsmooth mating coatings, each attractive to oil films.
摘要:
There are disclosed a method for lubricating treatment of an aluminum surface comprising subjecting the surface of aluminum or aluminum alloy to chemical zinc deposition plating, then to a treatment with a phosphating solution and further to a lubricating treatment, and a method for lubricating treatment of an aluminum surface comprising subjecting the surface of aluminum or aluminum alloy to chemical zinc deposition plating in a thickness of 0.2 .mu.m or more and further to a soap lubricating treatment.
摘要:
A device for electrostatically charging and dispensing a high resistivity cutting lubricant to a workpiece includes a source of high resistivity cutting lubricant and a capillary tube having an entrant end in fluid communication with the high resistivity cutting lubricant and a tapered discharge end forming a sharp point. A high voltage power supply is used for generating a high voltage of less than 5,000 volts d.c. The power supply has a positive terminal and a negative terminal. A high voltage electrode has its one end connected to the positive terminal of the power supply and has its other end operatively coupled to the discharge end of the capillary tube. A nearby grounded electrode is disposed in a spaced-apart relationship from the discharge end of the capillary tube so as to create a high electric field therebetween for electrostatically charging the lubricant. The lubricant is atomized and projected in the form of a steady and controlled stream of charged particles away from the discharge end of the capillary tube to within the vicinity of or all the way to the workpiece before the stream of charged particles bursts into an aerosol cloud of charged droplets for dispensing them onto the workpiece.
摘要:
An oxide type solid lubricant is made up of a sintered composite ceramic mass of Cr.sub.2 O.sub.3 and Na.sub.2 ZrO.sub.3 and has a Cr.sub.2 O.sub.3 content in the range of from 20 to 50% by weight.
摘要:
A method is provided for reducing the force required to move a pipe through a J-tube attached to an offshore platform by coating the pipe with hydrophilic polymer and then moving the pipe through the J-tube, or by introducing a solution of hydrophilic polymer and water into the J-tube and then moving the pipe through the J-tube.
摘要:
Piston has upper and lower portions. The upper portion includes a cylinder engaging surface, such as a piston ring, comprised of solid lubricant. The lower portion includes a cylinder engaging surface comprised of liquid lubricant control means. The distance between the upper and lower cylinder engaging surfaces is sufficient to provide a temperature differential of at least 316.degree. C. (600.degree. F.) between the upper and lower portions during normal engine operations. This differential is adequate to maintain the temperature of the cylinder at the bottom ring reversal point at a temperature below the breakdown temperature of a liquid lubricant when the temperature of the cylinder liner at the top ring reversal point is at a temperature above the breakdown temperature of the liquid lubricant.
摘要:
Thin films of solid lubricious metal chalcogenides, such as MoS.sub.2, are grown on stainless steel substrates by pulsed laser evaporation (P.L.E.). X-ray photoelectron spectroscopy of PLE deposited MoS.sub.2 films grown at substrate temperatures up to 300.degree. C. have the same stoichiometry as bulk MoS.sub.2. MoS.sub.2 PLE deposited films grown at 450.degree. C. are sulfur rich. These laser-deposited films have a granular structure and exhibit none of the dendritic structures typically observed in sputter-deposited films. The coefficients of friction of PLE films were measured in laboratory air and ranged from 0.09-0.25; the majority of values were between 0.16 and 0.20. These frictional coefficients are in the appropriate range for a solid lubricant.
摘要:
Reciprocating engine parts which involve substantially continuous frictional contact are coated with a solid film lubricant having excellent wear characteristics and adhesion. The parts in question are pistons, and the area to which the wear resistant solid lubricant film is bonded is the piston skirt--i.e., all or a portion of the area below the piston rings. The lubricant film is composed of a polyimide of 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane ("4-BDAF") and an aromatic tetracarboxylic acid (or dianhydride or ester thereof) containing from 25 to 125 parts by weight of fluorinated carbon per 100 parts by weight of the polyimide resin ("phr"), and preferably about 30 to about 100 phr of the fluorinated carbon.
摘要:
A plurality of lubricating plugs are disposed in the stationary backup face adjacent to the axial stop face of a rotating impeller mounted in a turbopump for pumping liquid oxygen or liquid hydrogen. The stop face and the backup face are those surfaces which engage when the axial load on the impeller exceeds the load balancing capability. The plugs have a truncated conical configuration so as to be trapped in the backup face, and are disposed at varying radii on the face to provide complete surface lubrication. The plugs may be formed from Teflon, Kel-F or bronze filled Teflon.
摘要:
A method of using an electrochemical process in oil-based lubricants to form friction-reducing and wear-reducing iron phosphate films on metal surfaces. An electrolytic additive of dialkyl hydrogen phosphate is first added to the oil-based lubricant to improve its electrical conductance and to make it an ionic conductor. This method enables not only the formation of uniform iron phosphate films on metal surfaces but also the in-situ repair of such films after damage has occurred.