Abstract: An eddy current coupling with an electrically controllable field current is used to rotatably connect a drive motor to an oil well pumping mechanism where the eddy current drive speed is controlled to a reference speed using a speed feedback control system and operation can be limited in torque output by a torque feedback control system. In a first alternative embodiment, the eddy current coupling output speed is controlled by a stroke modulation unit using a first selected speed for the upward pumping stroke and a second selected speed for the downward pumping stroke. In a second alternative embodiment a controller is used to select torque or speed control for the upward or downward .pumping stroke.

Abstract: An improved electromagnetic coupling apparatus is advantageously utilized in conjunction with an oil well pump assembly. The electromagnetic coupling apparatus includes rotatable inner and outer shafts. A stationary annular coil assembly is supported on the outer shaft by bearings which allow the outer shaft to rotate relative to the coil. A pole piece drum extends around the outer shaft and is effective to concentrate magnetic flux conducted from the stationary coil. A rotatable eddy current drum extends around the pole piece drum. The pole piece and eddy current drums are fixedly connected with the inner and outer shafts. The inner and outer shafts extend in the same axial direction from the pole piece and eddy current drums.

Abstract: A dynamic braking means for a variable speed dynamoelectric eddy current drive consists of an ac motor (4) rotationally coupled through a shaft (6) to an inductor drum assembly (13) of an eddy current coupling (3), where an annular field coil 12 generates an electromagnetic field which couples the inductor drum assembly to a pole assembly (10) which is rotationally coupled to an output shaft (16) which drives an inertial load (20). Upon command to stop and brake, a controller (30) signals a motor switch (26) to disconnect the ac motor from the ac source and connect it to a dc source, causing a braking torque to be produced. Concurrently, the controller signals a coupling switch (28) to go to an open position momentarily until the motor decelerates to approximately zero speed, whereupon the coupling switch is again closed, coupling the inertial load to the motor, thereby providing a braking action.

Abstract: An air-cooled eddy current dynamometer for the use in a vehicle emissions test stand application. The dynamometer housing includes an air inlet manifold for drawing cooling air radially inwardly into the dynamometer and an air outlet manifold permitting the expulsion of heated air tangentially outwardly from the dynamometer. An end of the dynamometer housing has a plurality of openings therein allowing cooling air to be drawn axially inwardly into the dynamometer housing. The combination of air flows radially inwardly through the inlet manifold, axially inwardly through the openings in the end of the dynamometer and tangentially outwardly through the outlet manifold significantly increases the cooling of the dynamometer permitting its use in a vehicle test stand application wherein the dynamometer is placed in a recess or pit within the floor of the structure in which the test stand is installed.

Abstract: An eddy current brake for braking the rotation of a rotating shaft driven by a drive including a rotatable, stamped one-piece inductor drum member connectable to a driven shaft, having a radially extending portion and an axially extending portion spaced from and substantially parallel to the axis of rotation of the driven shaft. A pole assembly is located within a volume defined by said drum member and is rigidly attached to an end adaptor plate of the drive. The pole assembly includes a pair of stamped pole members each defining a plurality of poles which are placed in a confronting, interdigitated relationship upon assembly.

Abstract: An eddy current coupling for a dynamo-electric machine. A flux path between a rotating drive shaft and a rotatable driven shaft includes an inductor drum connected to the drive shaft and a pole assembly coupled to the driven shaft. A coil assembly partially surrounded by the pole assembly controls the degree of electromagnetic coupling. A series of interdigitated pole fingers are spaced between the inductor drum and the field coil assembly to facilitate air flow that dissipates heat caused by relative rotation between the inductor drum and the pole assembly. The coil assembly includes an annular coil support co-axial with the driven shaft to support an annular field coil in a gap defined by the pole assembly.

Abstract: A low cost, linear, low impedance tachometer/generator includes a stator and a rotor. The rotor includes a plurality of magnetic poles which alternate between first and second polarities, and the stator includes a plurality of first and second annular sets of planar laminated poles which are spaced apart, with the first set of poles having a first polarity and the second set of poles having a second polarity. An annular coil is disposed between the first and second sets of poles. The first set of poles is axially spaced apart and circumferentially offset one pole pitch about the axis of rotation from the second set of poles to effect simultaneous periodic alignment of the first set of poles on the stator with the plurality of poles on the rotor of the second polarity and the second set of poles on the stator with the plurality of poles on the rotor of the first polarity.

Abstract: An eddy current coupling (11) includes a housing (13, 15, 17), a rotor member (29), inductor drum means (25) rotatable about an axis of rotation relative to the rotor member and coil means (41) for electro-magnetically coupling the rotor member and inductor drum means. The housing includes a non-circular central portion (13) having an opening at both ends thereof which is expandable in a radial direction perpendicular to the axis of rotation and first (15) and second (17) end members. The central portion of the housing defines a chamber (80) for receiving the rotor member, inductor drum means and coil means. The first and second end members include pilot surfaces (84, 90) thereon.

Abstract: An eddy current coupling (11) includes a housing (13, 15, 17), a rotor (29), an inductor drum means (25), coil means (41) for electro-magnetically coupling the rotor member and the inductor drum means and a slip ring assembly (45) for energizing the coil. The slip ring assembly includes a first support member (55) connected to the rotor member for rotation therewith, slip ring means (47, 49) for energizing the coil means supported by the first support member, a second support member (56) and brush means (51, 53) supported by the second support member. The first and second support members define a sealed chamber (80) in which the slip ring means and brush means are located. A passageway means (92) is provided from the sealed chamber for directing wear debris generated by the contact between the brush means and slip ring means from the sealed chamber. An impeller (98) is provided for impelling the debris through the passageway means and from the chamber.