Pilot stage or pressure control pilot valve having a single armature/flapper
AssigneeSauer-Danfoss Inc.
InventorWayne R. Anderson
Life of this patent
Estimating the term…
Abstract
An improved pilot stage includes a flapper having first and second ends, first and second nozzles in fluid communication with the first and second ends, and a magnetic torque motor having a first coil which is magnetically coupled to the first end of the flapper. An input current to the first coil creates a magnetic torque on the flapper, causing the flapper to pivot. The torque input from the magnetic circuit is reflected through the pivot to create a balancing differential pressure output at the nozzles proportional to the input electrical signal. The flapper does not require a torsion bar (or tube) pivot or a separate armature, as required by functionally similar pilot stages.
Claims17
A pilot stage, comprising:
- first and second nozzles that are connectable to a fluid supply;
- a flapper having a free floating pivot and first and second ends, the ends being in fluid communication with the nozzles;
- and
- a magnetic torque motor without a permanent magnet having a first coil that is connectable to an electrical energy source, the first coil being magnetically coupled to the first end of the flapper, wherein the flapper will pivot in response to an input current to the first coil causing one end of the flapper to move closer to one of the nozzles.
A method of creating a pressure differential between first and second nozzles coupled to a source of fluid, comprising:
- placing a flapper having a free floating pivot and first and second ends in fluid communication with the first and second nozzles;
- utilizing a magnetic torque motor to generate a magnetic torque to pivot the flapper whereby the first end of the flapper moves closer to the first nozzle and the second end of the flapper moves away from the second nozzle, creating a pressure differential between the nozzles.
A pilot stage which does not require a separate armature, comprising:
- first and second nozzles;
- a magnetic torque motor having a first coil, the first coil connectable to a source of electrical energy;
- a flapper having first and second ends and a free floating pivot pin, the pivot pin located substantially at a center of mass of the flapper, the ends being in fluid communication with the nozzles, the first end of the flapper being magnetically coupled to the first coil whereby an input current to the coil produces a magnetic torque that causes the flapper to pivot, thereby moving one of the ends of the flapper closer to one of the nozzles to create a pressure differential.
Dependencies are inferred from the claim text.