Vertical self-priming pump

A vertical self-priming pump, comprising

• a pump body, wherein the inner cavity of the pump body is divided into a gas-liquid separation chamber and a liquid storage chamber through a middle partition plate that is provided with an axial inlet opening, and the gas-liquid separation chamber is above the liquid storage chamber;
• a flow guide body is fixed on the upper surface of the middle partition plate;
• the flow guide body is provided with an axial through hole and a radial flow guide hole that is in communication with the axial through hole, and the gas-liquid separation chamber is in communication with the liquid storage chamber through the axial inlet opening and the radial flow guide hole on the flow guide body;
• a motor, which is fixed on the top of the pump body for driving a pump shaft that vertically downward penetrates into the inner cavity of the pump body to rotate, and an impeller that is arranged in the axial through hole of the flow guide body is fixed on the lower end of the pump shaft;
• a backflow gap channel is formed between the outer circumferential surface of the impeller and the inner wall of the axial through hole of the flow guide body;
• further comprising a medium backflow blocking device that comprises a static ring and a moving ring which are vertically and oppositely arranged as well as an elastic supporting sleeve;
• the moving ring is embedded on the upper surface of the impeller, and the outer edge of the elastic supporting sleeve extends downwards to form a supporter that is fixed on the upper surface of the flow guide body;
• the static ring is embedded on the lower surface of an elastic supporting ring, and the lower end surface of the static ring protrudes the lower surface of the elastic supporting sleeve, and a gap is formed between the lower end surface of the static ring and the upper end of the moving ring.