| 摘要 |
<p>An electrohydraulic servovalve comprising a torque motor (10) which receives an electrical signal and positions a flapper (11) of a spring tube and flapper subassembly (11, 21) between a pair of opposed nozzles (12) to control a spool valve (16) and includes a feedback spring (14) connected to the flapper (11) and to the spool (15) of the spool valve (16). A method of obtaining torque motor air gap symmetry is provided which comprises forming the pole piece/magnet subassembly (17, 18) to provide a desired total pole air gap on both ends of the armature (20), forming the armature ends so that they are equal to the total pole gap minus twice the desired nominal air gap, assembling the torque motor (10) before attaching the spring tube and flapper subassembly (11, 21), positioning the spring tube and flapper subassembly and the pole piece/magnets in a relative position to one another, providing spacers (36) between the lower edges of the armature (20) and the gap of the pole pieces, providing wedges (35) between the upper pole piece, providing a joint A between the tube (21) and the armature (20) by a hardenable material to bond the armature and the spring tube, and permitting the joint to harden and set. <IMAGE></p> |
