The Direct Acting High-Speed Servo Valve from Exsenco (DASV) is equipped with a specially designed magnetic array to create thrust. A voice coil of tandem differential configuration is inserted in the annular space of the magnetic array, and a spool is fixed at the end of the coil. The spool is fastened in such a way that it may move axially, and the setup is able to move freely together.
When current is supplied to the intense magnetic fields in the DASV, the voice coil generates a strong thrust, moving together with the spool in an axial direction. It is supplemented by detecting magnets at the opposite end of the spool to create an extremely stable feedback system. These magnets are arranged in such a way that the Hall element is able to detect positional signal, while the sensing coil can directly monitor the spool’s velocity signal. In the DASV, the Dual Halbach Magnet Array reinforces magnetic fields for driving differential voice coils in tandem. These incredibly dense magnetic fields make the valve capable of a very fast, accurate response in a very compact body.
Image credit: Exsenco, LLC