Assessment of the Electromagnetic Behaviour of Servovalve Torque Motor Using Reluctance Network Models

The torque motor is the most common technology used in electrohydraulic two-stage servovalves to drive the hydraulic pilot stage. As it is a key component in these valves, its performance considerably affects the overall performance of servovalve systems. Modeling accurately the magnetic behavior of the torque motor will help to get a more realistic performance of the servovalve at different operating conditions during the product design and development stage. In this paper, an advanced model of the torque motor is presented. The aim is to integrate it into the overall multiphysics model of the servovalve through a multi-variable function obtained using the proposed modeling tool. The advanced reluctance network model has been developed by progressively considering various magnetic phenomena, including flux leaks between different parts and variations in magnetic induction. This model allows rapid assessment of the magnetic performance at various operating temperatures or using different ferromagnetic materials, without the need for additional analysis in 3D finite element software.