Patent ID: 7819226

Claim:
A method of suppressing a wear in a friction system between two objects comprising: expressing a corresponding value between a maximum rotation speed and a percentage content of an insoluble content as a function of P(n)=p(n) of a maximum rotation speed n and a percentage content p of an insoluble content given by a continuous decreasing curve passing through a plurality of points: a point, at 100 rpm, 0.5 mass %; a point, at 750 rpm, 0.2 mass %; a point, at 1200 rpm, 0.1 mass %; a point, at 3000 rpm, 0.05 mass %; and a point, at 8000 rpm, 0.025 mass % on a graph adopting the maximum rotation speed n as a horizontal axis and the percentage content p of the insoluble content as a vertical axis, and regulating and maintaining the percentage content of the insoluble content with respect to the lubricating oil, using a precise filtering means, within a value range shown by P(n)=p(n)±0.05, including 0.05%, an effective error range as a percentage content P of an insoluble content to a chosen rotation speed, in a friction system in which the lubricating oil is interposed between the two objects for the purpose of suppressing a wear due to an abrasion of a friction surface in a contact periodical relative motion between the two objects, wherein, in P(n)=p(n)±0.05, if P(n)<0, the minimum value of P(n) is a finite minimum value larger than zero, and wherein the precise filtering means comprises a filter element formed by laminating a plurality of thin sheets, wherein the lubricating oil is passed through a paper laminated gap so as to make an impurity having a size equal to or more than 1 μm contained in the lubricating oil to be attached to a paper fiber on the basis of a molecular Brownian motion and be removed.