To provide a positive displacement pump capable of increasing discharge flow with high frequency of volume change of a pump chamber and high proportionality of discharge flow in the positive displacement pump comprising the pump chamber, an intake port and a discharge port opened to the pump chamber, an intake side check valve allowing fluid flow from the intake port to the pump chamber but not allowing the reverse fluid flow, a discharge side check valve allowing fluid flow from the pump chamber to the discharge port but not allowing the reverse fluid flow, and an actuator for periodically changing the volume size of the pump chamber.
The positive displacement pump is provided with a by-pass passage allowing the intake port and the discharge port to communicate with each other without going through the pump chamber, and provided with a one-way valve in the by-pass passage to allow fluid flow from the intake port to the discharge port.
| JP2000130338 | ELECTROMAGNETIC DIAPHRAGM PUMP |
| JP3958926 | METHOD FOR DISPENSING FLUID |
ISHIKAWA JUN
SATO TOSHIHIKO
WATABE MITSURU
