| 摘要 |
<p>PURPOSE:To prevent the generation of surge pressure at the time when a cylinder chamber communicates with a discharge port by providing a pin member on the inside of a spring which energizes a piston fitted in a rotor toward the outside of the rotor. CONSTITUTION:A pin 101 is inserted in a piston 103 to reduce pumping volume inside the piston 103 or a cylinder chamber 104. If the volume V inside the cylinder chamber 104 could be reduced to 1/2 by a noncompressible pin 101, it is enabled to raise the pressure rise DELTAP in the cylinder chamber 104 twice as much within the same precompression region. Accordingly, the pressure in the cylinder chamber 104 is sufficiently compressed within a precompression region to be precompressed to nearly the same pressure as the discharge side pressure of a discharge port 108 or a discharge port 109 before it is communicated. Thus, the generation of surge pressure in the cylinder chamber 104 is prevented, and the pulsation in the discharge pressure of a pump can be reduced.</p> |
