Modeling of a novel 3-way rotary type electro-hydraulic valve

Abstract

Hydraulic actuation is characterized by fast dynamics, high power density, high stiffness, large output force/torque, and in recent years it has become an increasing attractive form of robot actuation. Hydraulic control valves that not only provide the interface between hydraulic power element and actuators, but also receive feedback signal and adjust the system output accordingly, are key components of hydraulic actuation systems. This paper presents a novel 3-way rotary type electro-hydraulic valve which is driven by a DC motor. The valve is mainly composed of a rotary spool, a bush and a body. The operating principle is presented in details and a mathematical model is developed. In particular, the drag torque that majorly affects the valve performance is analyzed based on the theory of fluid mechanics.