WCB gear oil pump structure uses the isolation of coupling and medium, the coupling can lubricate alone, and the gear is made of alloy steel which adopts the special hot process technology, the hardness of surface can be reach to over HRC60, also has the strong anti abrasion and increasing the using life. Comparing with other common types, it in conveying no lubricating or less lubrication or little particle liquids, has strong application, and is the typical soap liquid pump.