Hydraulic Rotary Machine

Abstract

A sliding layer ( 21 ) of a sintered copper alloy is formed on a sliding surface ( 12 A) 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 ( 12 A) 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 % CaF 2 (calcium fluoride) as an essential component, and an average particle size of said CaF 2 is controlled to fall within the range from 40 μm to 350 μm. A sliding surface ( 8 A) 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.

1 . A hydraulic rotary machine, comprising:
 first members ( 8 ,  12 ,  13 ,  35 ,  44 ,  50 ) that include first sliding surfaces ( 9 A,  12 A,  13 A,  35 A,  45 A,  50 B,  50 C); and   second members ( 8 ,  11 ,  14 ,  34 ,  44 ,  49 ,  51 ) that include second sliding surfaces ( 8 A,  11 B,  14 A,  34 B,  34 D,  44 B,  49 B,  51 A) sliding with respect to said first sliding surfaces ( 9 A,  12 A,  13 A,  35 A,  45 A,  50 B,  50 C), wherein   one ends of oil passages ( 10 ,  11 C,  12 B,  12 C,  13 B,  35 B,  46 ,  50 D,  50 E), through which an hydraulic oil flows, open on at least any of said first sliding surfaces ( 9 A,  12 A,  13 A,  35 A,  45 A,  50 B,  50 C) and said second sliding surfaces ( 8 A,  11 B,  14 A,  34 B,  34 D,  44 B,  49 B,  51 A), characterized in that:   a sliding layer ( 21 ) formed of a sintered copper alloy is formed on one of said first sliding surfaces ( 9 A,  12 A,  13 A,  35 A,  45 A,  50 B,  50 C) and said second sliding surfaces ( 8 A,  11 B,  14 A,  34 B,  34 D,  44 B,  49 B,  51 A);   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 % CaF 2  as an essential component, and an average particle size of said CaF 2  is controlled to fall within a range from 40 μm to 350 μm; and   the other sliding surface of said first sliding surface ( 9 A,  12 A,  13 A,  35 A,  45 A,  50 B,  50 C) and said second sliding surface ( 8 A,  11 B,  14 A,  34 B,  34 D,  44 B,  49 B,  51 A) is formed of a sliding layer of iron-and-steel materials.   
     
     
         2 . The hydraulic rotary machine according to  claim 1 , wherein
 said remainder of said sliding layer ( 21 ) has a composition including at least one component or more selected from the group consisting of Pb, Ni, Be, P, Fe, Zn, Al, Si, Mn, Mg, S, Ti, V, Cr and W, in addition to said CaF 2  as the essential component.   
     
     
         3 . The hydraulic rotary machine according to  claim 2 , wherein
 a composition of said principal components of said sliding layer ( 21 ) includes 11 wt % to 13 wt % of said Sn in addition to said Cu; and   a composition of said remainder of said sliding layer ( 21 ) includes 4 wt % to 6 wt % of said Ni in addition to said CaF 2 .   
     
     
         4 . The hydraulic rotary machine according to  claim 2 , wherein
 a composition of said principal components of said sliding layer ( 21 ) includes 11 wt % to 13 wt % of said Sn in addition to said Cu; and   a composition of said remainder of said sliding layer ( 21 ) includes 1 wt % to 3 wt % of said Pb and 4 wt % to 6 wt % of said Ni in addition to said CaF 2 .   
     
     
         5 . The hydraulic rotary machine according to  claim 1 , wherein
 said remainder of said sliding layer ( 21 ) includes Pb and Ni as essential components in addition to said CaF 2  as the essential component, and said CaF 2  is controlled to include 90 wt % to 100 wt % of said CaF 2  having particle sizes falling within the range from 40 μm to 350 μm.   
     
     
         6 . The hydraulic rotary machine according to  claim 1 , comprising:
 a hollow casing ( 2 ,  31 ,  41 );   a rotational shaft ( 5 ,  42 ) that is rotatably mounted inside said casing ( 2 ,  31 ,  41 );   a cylinder block ( 8 ,  44 ) that is placed inside said casing ( 2 ,  31 ,  41 ) to rotate together with said rotational shaft ( 5 ,  42 ), said cylinder block ( 8 ,  44 ) being provided with a plurality of cylinders ( 9 ,  45 ) formed therein to be spaced in a circumferential direction and extend in an axial direction, and cylinder ports ( 10 ,  46 ) formed to open on an end face in positions corresponding to said respective cylinders ( 9 ,  45 );   a plurality of pistons ( 11 ,  49 ) that are inserted into said respective cylinders ( 9 ,  45 ) of said cylinder block ( 8 ,  44 ) to be capable of reciprocating therein; and   a valve plate ( 12 ,  50 ) that is placed between said casing ( 2 ,  31 ,  41 ) and said cylinder block ( 8 ,  44 ) and includes supply and discharge ports ( 12 B,  12 C,  50 D,  50 E) formed to communicate with said respective cylinders ( 9 ,  45 ) through said cylinder ports ( 10 ,  46 ), wherein   said first member comprises said valve plate ( 12 ,  50 ) including said supply and discharge ports ( 12 B,  12 C,  50 D,  50 E) formed to be said oil passages; and   said second member comprises said cylinder block ( 8 ,  44 ) sliding on said valve plate ( 12 ,  50 ) and including said cylinder ports ( 10 ,  46 ) formed to be said oil passages.   
     
     
         7 . The hydraulic rotary machine according to  claim 1 , comprising:
 a hollow casing ( 2 ,  31 );   a rotational shaft ( 5 ) that is rotatably mounted inside said casing ( 2 ,  31 );   a cylinder block ( 8 ) that is placed inside said casing ( 2 ,  31 ) to rotate together with said rotational shaft ( 5 ), said cylinder block ( 8 ) being provided with a plurality of cylinders ( 9 ) formed therein to be spaced in a circumferential direction and extend in an axial direction, and cylinder ports ( 10 ) formed to open on an end face in positions corresponding to said respective cylinders ( 9 );   a plurality of pistons ( 11 ) that are inserted into said respective cylinders ( 9 ) of said cylinder block ( 8 ) to be capable of reciprocating therein and include first oil supply ports ( 11 C) formed therein;   a valve plate ( 12 ) that is placed between said casing ( 2 ,  31 ) and said cylinder block ( 8 ) and includes supply and discharge ports ( 12 B,  12 C) formed to communicate with said respective cylinders ( 9 ) through said cylinder ports ( 10 );   a plurality of shoes ( 13 ) that are mounted to projecting ends of said respective pistons ( 11 ) to be capable of tilting around and include second oil supply ports ( 13 B) formed therein to be connected to said first oil supply ports ( 11 C); and   a swash plate ( 14 ,  34 ) that is placed on the opposite side of said cylinder block ( 8 ) from said valve plate ( 12 ) and on which said respective shoes ( 13 ) slide, wherein   said first member comprises each of said shoes ( 13 ) including said second oil supply port ( 13 B) formed to be said oil passage; and   said second member comprises said swash plate ( 12 ) on which each of said shoes ( 13 ) slides.   
     
     
         8 . The hydraulic rotary machine according to  claim 1 , comprising:
 a hollow casing ( 2 ,  31 ,  41 );   a rotational shaft ( 5 ,  42 ) that is rotatably mounted inside said casing ( 2 ,  31 ,  41 );   a cylinder block ( 8 ,  44 ) that is placed inside said casing ( 2 ,  31 ,  41 ) to rotate together with said rotational shaft ( 5 ,  42 ), said cylinder block ( 8 ,  44 ) being provided with a plurality of cylinders ( 9 ,  45 ) formed therein to be spaced in a circumferential direction, and cylinder ports ( 10 ,  46 ) formed to open on an end face in positions corresponding to said respective cylinders ( 9 ,  45 ); and   a plurality of pistons ( 11 ,  49 ) that are inserted into said respective cylinders ( 9 ,  45 ) of said cylinder block ( 8 ,  44 ) to be capable of reciprocating therein, wherein   said first member comprises said cylinder block ( 8 ,  44 ) including said cylinder ports ( 10 ,  46 ) formed to be said oil passages; and   said second member comprises said pistons ( 11 ,  49 ) sliding with respect to said cylinders ( 9 ,  45 ) of said cylinder block ( 8 ,  44 ).   
     
     
         9 . The hydraulic rotary machine according to  claim 1 , comprising:
 a hollow casing ( 31 );   a rotational shaft ( 5 ) that is rotatably mounted inside said casing ( 31 );   a cylinder block ( 8 ) that is placed inside said casing ( 31 ) to rotate together with said rotational shaft ( 5 ), said cylinder block ( 8 ) being provided with a plurality of cylinders ( 9 ) formed therein to be spaced in a circumferential direction and extend in an axial direction, and cylinder ports ( 10 ) formed to open on an end face in positions corresponding to said respective cylinders ( 9 );   a plurality of pistons ( 11 ) that are inserted into said respective cylinders ( 9 ) of said cylinder block ( 8 ) to be capable of reciprocating therein;   a valve plate ( 12 ) that is placed between said casing ( 31 ) and said cylinder block ( 8 ) and includes supply and discharge ports ( 12 B,  12 C) formed to communicate with said respective cylinders ( 9 ) through said cylinder ports ( 10 );   a plurality of shoes ( 13 ) that are mounted to projecting ends of said respective pistons ( 11 ) to be capable of tilting around;   a swash plate ( 34 ) that includes one end face facing said cylinder block ( 8 ) to allow each of said shoes ( 13 ) to slide thereon and the other end face on which a convex-curved sliding surface ( 34 D) is formed, and is tiltably mounted to tilt about a swash-plate supporting point; and   a swash plate support member ( 35 ) that includes a concave-curved tilting slide surface ( 35 A) formed to allow said sliding surface ( 34 D) of said swash plate ( 34 ) to slide thereon, and an oil supply port ( 35 B) formed therein for passage of the hydraulic oil supplied from said cylinder ports ( 10 ), wherein   said first member comprises said swash plate support member ( 35 ) including said oil supply port ( 35 B) formed therein to be said oil passage; and   said second member comprises said swash plate ( 34 ) sliding with respect to said swash plate support member ( 35 ).   
     
     
         10 . The hydraulic rotary machine according to  claim 1 , comprising:
 a hollow casing ( 41 );   a rotational shaft ( 42 ) that is rotatably mounted inside said casing ( 41 ) and includes a drive disk ( 42 A) at a top end;   a cylinder block ( 44 ) that is placed inside said casing ( 41 ) to rotate together with said rotational shaft ( 42 ), said cylinder block ( 44 ) being provided with a plurality of cylinders ( 45 ) formed therein to be spaced in a circumferential direction and extend in an axial direction, and cylinder ports ( 46 ) formed to open on an end face in positions corresponding to said respective cylinders ( 45 );   a plurality of pistons ( 49 ) that are inserted into said respective cylinders ( 45 ) of said cylinder block ( 44 ) to be capable of reciprocating therein, and include projecting ends supported by said drive disk ( 42 A) of said rotational shaft ( 42 ) to be capable of tilting therein;   a valve plate ( 50 ) that includes one end face facing said cylinder block ( 44 ) to allow said cylinder block ( 44 ) to slide thereon and the other end face on which a convex-curved sliding surface ( 50 B) is formed, and is tiltably mounted to tilt together with said cylinder block ( 44 ) about a valve-plate supporting point; and   a head cover ( 51 ) that includes a concave-curved tilting slide surface ( 51 A) to allow said sliding surface ( 50 C) of said valve plate ( 50 ) to slide on, wherein   said first member comprises said valve plate ( 50 ) including supply and discharge ports ( 50 D) formed to be said oil passages communicating with said respective cylinders ( 45 ) through said cylinder ports ( 46 ); and   said second member comprises said head cover ( 51 ) on which said valve plate ( 50 ) slides.