| 摘要 |
PURPOSE:To prevent generation of a cavitation and noise by communicating a cylinder port with a low pressure port till the piston is shifted to pass over the bottom dead point. CONSTITUTION:The terminal of a low pressure port 22, the starting end of a high pressure port 21 and the starting end of a notch 23 are shifted in the rotating direction of a cylinder block respectively by DELTAtheta so that a cylinder port 13 is communicated with the low pressure port 22 untill a piston is shifted to pass over the bottom dead point. The peak of speed Va of the fluid passing through an overlapped portion A in the vicinity of the dead bottom point is decreased as the DELTAtheta is increased. The peak of Va in the vicinity of the dead bottom point is decreased to zero when the DELTAtheta becomes more than about 4 deg.. As a result, there is no fear of generation of a cavitation or the like in the cylinder. |
