| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a slanting moment acting on a piston and to reduce the wear of a piston guide to thereby improve a life of a piston pump by providing a cutout in the region of a sliding surface and a sliding bearing surface and by making a load reducing room partitioned by the cutout communicate with a working room. SOLUTION: A piston pump has, for example, three pump elements 11 arranged in a star shape in a casing 10 and each pump element 11 has a piston 12 fitted in a piston guide 13. Each piston 12 has at the end part protruded from the piston guide 13 a sliding shoe 15 having a sliding surface 16 and is reciprocated by the rotation of a cam ring 18 via the shoe 15. To reduce a force pressing the sliding shoe 15 on a stroke ring 18, a load reducing chamber 22 opening to the sliding bearing surface 17 of the stroke ring 18 is formed and communicates with a working chamber 25 of the pump element 11 via a through opening 23 made in the shoe 15.</p> |
