Simple structure, low noise, smooth oil delivery, strong self-priming performance and good low and high speed characteristics. The pump is suitable for continuous or intermittent oil supply lubrication at low and medium pressure in lubrication systems, and also for low speed oil supply lubrication. The products are widely used in the lubrication system of machinery and equipment of CNC machinery, processing centres, production lines and machine tools, forging and pressing textile, plastic, rubber, mining, construction, printing, chemical and food industries and the introduction of machinery and equipment.