Abstract: A vector controlled system for two AC induction linear motors to effect dual axis planar motion. There are two or four motors located in a shuttle element. The element is mounted on a smooth face, which includes a glass surface on which the shuttle moves on an air bearing. Vector control for each of the motors accurately controls motor operation in a single axis. Accurate control of a shuttle is obtained in the orthogonal movement under the action of the motors which are respectively arranged for relatively orthogonal movement. Feedback means between the motors and linear scales formed in the backiron associated with the glass face facilitates the controlled positioning of the motors and the shuttle element on the glass face.

Abstract: A stepper motor includes a forcer wherein the teeth are formed in the pole faces by an etching process or machining and instepping. The etching can be achieved by forming the teeth in a separately formed plate which is anchored to the face of a forcer. A high density magnetic material is used for the plate and can also be used on the platen to improve performance of the stepper motor.

Abstract: A stepper motor includes a forcer wherein the teeth are formed in the pole faces by an etching process or machining and instepping. The etching can be achieved by forming the teeth in a separately formed plate which is anchored to the face of a forcer. A high density magnetic material is used for the plate and can also be used on the platen to improve performance of the stepper motor.

Abstract: A system for detecting movement of a forcer of a motor directed for effecting movement of a forcer in a first direction in response to command pulses. There is a toothed platen for locating the forcer so that the forcer is movable over the platen. A magnetic structure is attached to move with the forcer and has a periodic configuration corresponding to the forcer and in magnetic interchange relation to the platen. A magnetic circuit is associated with the magnetic structure. Flux sensors generate signal variations corresponding to flux variations as the forcer moves relative to the teeth of the platen. The signal variations provide step count signals, and the step count signals are compared to the command pulses to detect a disparity.

Abstract: A linear motor system for providing XY motion comprises a first linear motor directed for effecting movement of a first element in a first of two orthogonal directions. There is a second linear motor directed for effecting movement of a second element in a second of the orthogonal directions. The motors are mounted on a base such that the elements are located and movable in a single plane in the respective orthogonal directions relative to each other over the base. A shuttle is reactive with the two elements such that movement of the elements effects XY movement of the shuttle. The elements and the shuttle are connected through a bearing force. The bearing force is created selectively by a vacuum attracting force cooperating with an air bearing repelling force, a magnetic attracting force cooperating with an air bearing repelling force, an air bearing repelling force in a first direction and an air bearing repelling force in an opposite direction, or a mechanical linkage.

Abstract: A linear motor system for providing XY motion comprises a first linear motor directed for effecting movement of a first element in a first of two orthogonal directions. There is a second linear motor directed for effecting movement of a second element in a second of the orthogonal directions. The motors are mounted on a base such that the elements are located and movable in a single plane in the respective orthogonal directions relative to each other over the base. A shuttle is reactive with the two elements such that movement of the elements effects XY movement of the shuttle. The elements and the shuttle are mounted on air bearings and interaction of the shuttle with the elements is also through an air bearings to control angular movement of the shuttle. This system provides for very fine movement in an XY direction which can be precisely controlled while angular movement of the shuttle is prevented.

Abstract: A linear induction motor system employs a driven reactive element that is oppositely influenced by a pair of spaced apart devices extending along a predetermined path. By altering the relationship between the reactive elements and devices, the net driving force on the driven element is varied so that a desired velocity profile can be established, and stable index positions can be defined. The principle is advantageously used in controlling a series of independent carts in a material conveyor system, in an arrangement which incorporates secondary positional control device along the cart path, and probe means for inhibiting interference between successive carts.

Abstract: An aligner or positioning system for moving a member in any direction in a horizontal plane includes a planar member having an upper horizontal surface and a platform movable above the horizontal surface. Driving coils extending along either of two orthogonal directions are disposed in one of the members while a pattern of oppositely magnetized permanent magnet elements is disposed in the other in flux coupling relationship. Energization of windings in appropriate senses, in accordance with the position of the platform, generates relative movement in one or both of two orthogonal directions, which may include angular movement as well.

Abstract: A bidirectional DC motor having a rotatable permanent magnet rotor structure within a ring core bearing helical windings is arranged to provide smoothly continuous torque over very wide excursion angles, which may be continuous if desired. Signals as to actual angular position of the rotor are utilized to generate timing signals for switching a driving current in proper polarity between different windings such that the extent and force of interaction fields remain substantially constant. The windings occupy different arc segments on the ring core and are energized such that all rotor tip regions are uniformly acted upon as the rotor moves from one arc segment to another.

Abstract: A bottom hole well pump comprising a pump housing supported by a control cable for raising and lowering the housing within tubing in a well, a linear motor within the housing causing reciprocation of a plunger extending into a pumping chamber formed by the housing with inlet and outlet check valves for controlling flow of oil or other liquid into the pumping chamber and from the pumping chamber into the tubing above the pump housing. In one embodiment, Belleville-type springs are employed for storing energy as the plunger approaches its opposite limits of travel in order to initiate movement of the plunger in the opposite direction. In this embodiment, a single pumping chamber is formed above the linear motor with a single-valve block arranged above the pumping chamber and including inlet check valve means for controlling liquid flow into the pumping chamber and outlet check valve means for controlling liquid flow from the pumping chamber into the tubing interior above the pump housing.

Abstract: A linear stepping motor comprising a stator having a central passageway extending therethrough and a secondary in the form of an elongated cylindrical member disposed within the passageway. The stator is formed of a plurality of coil groups, each group including at least one hollow coil disposed between a pair of magnetic stator plates. The coil groups are disposed co-axially, with immediately adjacent groups separated by respective hollow non-magnetic spacer. The secondary includes a plurality of annular rings of magnetic material disposed at equally spaced locations along the secondary. The coil groups are sequentially pulsed by electrical energy to effect the stepwise movement of the secondary along the passageway.In one embodiment the secondary is a magnetic material rod having a plurality of peripheral grooves cut at equally spaced locations therealong, with the portions of the rod between the grooves forming the annular rings.