A new double-cylinder metering pump with high precision and high sensitivity

Metering pump is a conventional loading analysis instrument, widely used in metrology, petroleum and chemical industry, with the functions of injection and loading, fluid displacement, metering control, etc. At present, the conventional metering pumps used in China have problems in practical application such as slow loading and pressure boosting, drastic fluctuations in holding pressure, large metering errors and complicated program control operations, which cannot meet the technical function and parameter requirements of cutting-edge scientific research experimental instruments in various fields, such as cyclic high-frequency loading and unloading for rock mechanics testing, and seepage displacement of rock microscopic pores. Based on the above problems, this paper develops a new doublecylinder metering pump with high precision and high sensitivity. The device innovatively uses the top-pressure loading technology of halberd gear rotating nut, which has multiple loading functions such as constant pressure and steady pressure, constant speed loading, controllable pulse and vibration, and can monitor the porosity evolution of rock specimens under the action of cyclic loading and unloading in real time. The device lays a theoretical foundation for studying the safety evolution mechanism of a series of rock engineering such as water conservancy mines and oil exploitation, and improves the scientific basis.