| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a piston pump motor having a confinement preventive groove capable of reducing vibration and noise caused by this vibration in a rotational area of a very wide range of a pump of the piston pump motor. SOLUTION: This piston pump motor is provided with an autorotating cylinder block 16, a plurality of piston holes arranged in this cylinder block 16, a piston 18 fitted and inserted in these respective piston holes, a valve plate 24 slidingly contacting with the cylinder block 16, and having respective suction and delivery ports, a pressure oil introducing groove 8 extended toward the other port from one end on the side for increasing the opening area to one port of the respective piston holes according to rotation of the cylinder block 16 to the reverse side of a surface for slidingly contacting with the cylinder block 16 of the valve plate 24, and a plurality of pores 6 almost vertically arranged to the surface for slidingly contacting with the cylinder block 16 of the valve plate from this pressure oil introducing groove 8. The plurality of pores 6 are constituted so as to increase the number in the rotational direction of the cylinder block 16.</p> |
