Hydraulic Rotary Machine

摘要

A sliding layer (21) of a sintered copper alloy is formed on a sliding surface (12A) of a valve plate (12). That is, the valve plate (12) is formed of iron-based materials such as cast iron or steel. Then, the sliding surface (12A) which is the front side of the valve plate (12) is covered with the sliding layer (21) formed of a sintered copper alloy containing Cu (copper) and Sn (tin) as principal components and the remaining components as the remainder. The remainder has 2 to 6 wt % CaF2 (calcium fluoride) as an essential component, and an average particle size of said CaF2 is controlled to fall within the range from 40 μm to 350 μm. A sliding surface (8A) of a cylinder block (8) which is a opposing part sliding surface is not covered with the copper-alloy sliding layer (21) but is covered with a sliding layer of iron-and-steel based materials.

主权项

1. A hydraulic rotary machine, comprising:
first members (8, 12, 13, 35, 44, 50) that include first sliding surfaces (9A, 12A, 13A, 35A, 45A, 50B, 50C); and second members (8, 11, 14, 34, 44, 49, 51) that include second sliding surfaces (8A, 11B, 14A, 34B, 34D, 44B, 49B, 51A) sliding with respect to said first sliding surfaces (9A, 12A, 13A, 35A, 45A, 50B, 50C), wherein one ends of oil passages (10, 11C, 12B, 12C, 13B, 35B, 46, 50D, 50E), through which an hydraulic oil flows, open on at least any of said first sliding surfaces (9A, 12A, 13A, 35A, 45A, 50B, 50C) and said second sliding surfaces (8A, 11B, 14A, 34B, 34D, 44B, 49B, 51A), characterized in that: a sliding layer (21) formed of a sintered copper alloy is formed on one of said first sliding surfaces (9A, 12A, 13A, 35A, 45A, 50B, 50C) and said second sliding surfaces (8A, 11B, 14A, 34B, 34D, 44B, 49B, 51A); said sliding layer (21) has a composition including Cu and Sn as principal components and the remainder as remaining components; said remainder includes 2 wt % to 6 wt % CaF2 as an essential component, and an average particle size of said CaF2 is controlled to fall within a range from 40 μm to 350 μm; and the other sliding surface of said first sliding surface (9A, 12A, 13A, 35A, 45A, 50B, 50C) and said second sliding surface (8A, 11B, 14A, 34B, 34D, 44B, 49B, 51A) is formed of a sliding layer of iron-and-steel materials.