Concept and modelling of the electrohydraulic valve with DC and stepper motors

The article describes concept and modelling of a new type of electrohydraulic valve controlled by the combination of a stepper motor and a DC motor. The aim of this invention is to use in the proportional valve two motors with the different properties. Both motors are responsible for the movement of a valve spool. The stepper motor and the DC motor are connected to a shaft by using a bellows coupling. Transfer from rotary to linear motion is performed by use of a bolt-nut system. According to the invention, presented here valve can be used in hydraulic drive systems with high positioning accuracy requirement. The author was granted a patent no. P.421994 on the invention described in this paper