Abstract: An object of the invention is to provide a system for suppressing a wear due to a friction of a friction system between two objects, particularly suppressing a wear due to a friction between a cylinder and a piston in an internal combustion engine to the minimum, increasing a reliability of the internal combustion engine to the maximum, and extending an interval of an overhaul to the maximum. The system is characterized in that an insoluble content is regulated in correspondence to the maximum rotation speed of a relative motion so as to be within a range of a specific optimum percentage content with respect to a lubricating oil so as to be contained, and is maintained, in a friction system in which the lubricating oil is interposed between two objects for the purpose of suppressing a wear due to a friction of a friction surface in a contact periodical relative motion between the two objects.

Abstract: An object of the invention is to provide a system for suppressing a wear due to a friction of a friction system between two objects, particularly suppressing a wear due to a friction between a cylinder and a piston in an internal combustion engine to the minimum, increasing are liability of the internal combustion engine to the maximum, and extending an interval of an overhaul to the maximum. The system is characterized in that an insoluble content is regulated in correspondence to the maximum rotation speed of a relative motion so as to be within a range of a specific optimum percentage content with respect to a lubricating oil so as to be contained, and is maintained, in a friction system in which the lubricating oil is interposed between two objects for the purpose of suppressing a wear due to a friction of a friction surface in a contact periodical relative motion between the two objects.

Abstract: The total or a partial quantity of lubricant oil for automotive vehicles is exchanged at a gas service station when a vehicle visits for its fuel supply. The lubricant oil is maintained with low values of contaminates, while extracted waste oil is purified and supplemented with lacking additive agents for reuse as fresh lubricant oil. An impurities removal equipment has a centrifuge and a filter device for the purification.

Abstract: A method for preventing damage to valve faces and valve seat faces and also for preventing partial gas escape, which is mainly caused by solid particles generated by the reaction between incomplete combustion materials produced during engine operation and additive agents included in lubricant oils as well as by adherence of metal dust on the faces by filtering out selected particles.The solid particles are produced by the reaction of carbon as an incomplete combustion material in an engine with calcium, zinc, phosphorus, magnesium and so on which are included in the additives of the lubricant oils as well as with solid impurities generated by incombustibles included in fuel, and also with metal dust. Particles and impurities bigger than 1 .mu.m are removed by filter device composed of many piled thin papers, while the same smaller than 1 .mu.m are retained in the lubricant oil. The valve face and the valve seat face surfaces are maintained clean and smooth.

Abstract: This invention relates to an apparatus for filtration of lubricating oil which lubricates an internal combustion engine as used in an automobile, a ship, etc. A filter element which is made of filter paper accumulated in layers and a pressure-receiving plate which receives pressure loaded on the lubricating oil during the operation of the internal combustion engine are provided in the filtration apparatus wherein the pressure-receiving plate compresses the filter element in compliance with pressure variations so as to prevent a leak passage from being formed by partial transformation of the filter element.