| 摘要 |
<p>PURPOSE: To reduce friction and wear and to enhance the extent of efficiency as well as to make improvements in durability by making a part of a discharge port of a valve plate wider than the other parts. CONSTITUTION: Plural pieces of cylinders bores 61 are installed on the same pitch circle from the center of a cylinder block 60 built in the inner part of a device body free of rotation in parallel with a turning center shaft A or the main shaft. This piston-pump is so structured that each piston 62 reciprocates in the cylinder bores 61, sucking and discharging a fluid with the rotation of the cylinder block 60 synchronizing with the rotation of a rotation transmitting shaft 70 installed concentrically with the turning center shaft A. In this constitution, a tip of a discharge port 12 of a valve plate 11 is provided with a discharge port 13 being wider than the other parts of the discharge port. With this discharge port 13, the extent of opening force is locally increased, avoiding any slide motion of high surface pressure sofar produced in the vicinity of a bottom dead center. Thus, friction and wear and reduced and efficiency is enhanced and durability is well improvable.</p> |
