Patent ID: 6283009
Filing Date: 2001-09-04
Classification: F04B,F16H

Abstract:
A swash plate type hydraulic unit comprising:a cylinder block (4) having a multitude of cylinder bores (25, 39) arranged annularly in parallel with a cylinder block axis (X) on a pitch circle (C.sub.1) which surrounds said axis (X),a multitude of plungers (27, 41) slidably fitted respectively in the cylinder bores (25, 39), anda plunger swash plate (9a, 19a) for rotating relatively with respect to the cylinder block (25, 39), thereby causing the plungers (27, 41) to reciprocate,characterized in that:said cylinder block (4) is formed by combining a plurality of block plates (4.sub.1 to 4.sub.5) with one another, said block plates being divided at split planes extending orthogonal to the cylinder block axis (X);said cylinder bores (25, 39) are comprised of inlet holes (25i, 39i) for supporting corresponding said plungers (27, 41) slidably and inner holes (25o, 39o) of a diameter larger than that of said inlet holes (25i, 39i), said inlet holes (25i, 39i) being formed in an inlet-side one of said block plates (4.sub.1, 4.sub.2 ; 4.sub.4, 4.sub.5) positioned on a side which faces the plunger swash plate (9a, 19a), said inner holes (25o, 39o) being formed in remaining inner-side ones of said block plates (4.sub.3 to 4.sub.5 ; 4.sub.1 to 4.sub.3) to each define an oil chamber between said inner hole and the outer peripheral surface and end surface of the corresponding plunger (27, 41);said cylinder block (4) has positioning means (58) for coaxially arranging the cylinder bores (25, 39) in the block plates (4.sub.1 to 4.sub.5);said cylinder block (4) is provided with a plurality of valve holes (26, 40) having distributing valves (28, 42) mounted therein; andports (25i, 39i) of the respective cylinder bores (4) are formed in groove shapes in the split plane of a part (4.sub.3) of the block plates so as to be controlled selectively by said distributing valves (28, 42).