Abstract:Modern water hydraulic transmission technology is a new technology in the field of fluid transmission. But as the core component of modern water hydraulic transmission, the water hydraulic pump whose development maturity has a big gap compared with oil hydraulic pump is restricted by various factors, and it is very difficult to develop. A new type of water hydraulic variable pump with oil hydraulic proportional system controlled is presented. The water hydraulic variable pump adopted the mixed design structure of water hydraulic components and oil hydraulic components, only a small amount of simple structure, low technology requirements of the water hydraulic components were used in the structure. The part of drive and control use mature and reliable oil hydraulic components, which made the difficulty of development of the water hydraulic variable pump greatly reduced. In addition, as a kind of oil hydraulic and water hydraulic integrated component with high degree of integration of requirement, it was one of the key problems for structural design to solve that achieved the purpose of small volume, light weight, and compact structure. However, the oil tank of the hydraulic system had the greatest influence on the volume of the water hydraulic pump. Therefore, combining with the characteristics of the new type of water hydraulic variable pump, and the watercooled oil tank is used to reduce the volume of the tank efficiently by optimizing the design through the Fluent software.