摘要 |
A two-stage pneumatic servo valve assembly for controlling an output motor is disclosed. An input device, such as a torque motor, is coupled to the two-stage servo valve assembly. The first stage of the servo valve assembly includes a vane valve movable by the output of the torque motor to selectively provide a fluid path from an input source to one of the first-stage output channels. The first-stage pneumatic servo valve is coupled with a second stage servo valve. The second stage servo valve controls fluid flow from a pneumatic fluid source to an output motor. The second stage servo valve includes a slidable spool valve movable by fluid received from the first-stage servo valve. A feedback control from the second-stage servo valve to the first-stage servo valve is provided. A second feedback control is provided from the output of the output motor to the first stage servo valve.
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