Stainless steel gear pumps are mainly composed of 5 parts, namely, gear, shaft, pump body, safety valve and shaft end seal. The gear has high hardness and strength through heat treatment and is installed with the shaft in the replaceable shaft sleeve. The lubrication of all parts in the pump is automatically achieved by using the output medium when the pump works. The pump has a reasonable design of oil drain and oil return tank, which is the smallest torque load in the gear, so the bearing load