Pneumo Corporation

Pneumo Abex Corporation

William H Eiszner, Jr

Robert D Vanderlaan

Stanley D Heeres

Thomas W Huitema

Linear direct drive motor includes a pair of axially spaced, relatively fixed stator poles and an armature mounted on a motor shaft for axial movement between the stator poles. The ends of the motor shaft are supported by centering springs which permit axial movement of the shaft and thus the armature relative to the stator poles. Positive stops are located between the stator and stator poles for preventing armature overtravel. Extending between the stator poles is a sleeve member which supports a ring magnet in radially spaced relation from the armature. Adjacent opposite ends of thee ring magnet are a plurality of layers of electrical coils, with the layers adjacent one end of the magnet being paired with different layers at the other end to provide redundant electrical channels and symmetric motion behavior.

Linear direct drive motor

A two-pole limited angle torque motor including a rotor assembly having one or more permanent rotor magnets and a stator assembly including a stator coil and a pair of circumferentially spaced stator pole structures. Each pole structure includes a generally axially extending stator pole blade about which the stator coil circumferentially extends. A radially outwardly extending flange is at one end of one of the stator pole structures and at the opposite end of the other stator pole structure. The stator pole blades have a greater radial thickness adjacent the flanges thereof than at the opposite end of the blade to reduce the magnetic flux density of the stator pole structures in the region of the blades adjacent the flanges thereof. Also, the axial outer end faces of the flanges desirably protrude axially outwardly adjacent the radial inner ends thereof to make use of the fringing fields of the rotor magnet at the ends of the rotor assembly to increase the reluctance torque of the motor. At the ends of the stator assembly opposite the stator pole flanges on opposite sides of the rotor assembly are additional stator pole pieces. The blades of the stator pole structures terminate short of the other ends of the rotor magnet to provide room for the additional stator pole pieces at such other ends for a given rotor length whereby the motor has a substantially higher reluctance torque without significantly reducing the torque due to interaction of magnetic fields. Surrounding the stator assembly is an outer magnetic housing comprising two semi-cylindrical parts with air gaps between opposite sides thereof, said housing parts being rotatable relative to each other to change the size of one gap relative to the other or otherwise machinable to change both gaps equally for adjusting the reluctance torque of the motor.

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Portage, MI, United States of America

William H Eiszner, Jr