Abstract: A brushless dc linear actuator includes a guide rail which extends in a longitudinal direction, and at least one moving member such as a slide, each of which is movable along the guide rail in the longitudinal direction. Each moving member includes permanent magnets. Rail supports are provided for each end of the guide rail and for holding the guide rail substantially horizontal. The moving member is propelled electromagnetically forward and backward along the rail by sequential activation of at least one series of electromagnetic coils distributed longitudinally with a predetermined pitch. A Hall-effect arrangement, including one Hall-effect element adjacent to each coil, provides non-impulsive, gradual activation and shut-off of active ones of the coils within a predetermined distance of the permanent magnets of the moving member. The pitch of the coils is determined as a precise function of the width of the permanent magnets, a phase simulation constant, and a coil selection constant.

Abstract: A rotor for an eddy current type retarder produces a brake force by producing eddy current using magnets mounted on a stationary member of the retarder. The rotor is mounted on a rotatable shaft and faces the magnets. The base member is made from a material containing steel. A thin film is formed on that face of the base member which faces the magnets. The film is made from a material containing rust-preventative material. A plurality of fins are formed on the base member by casting, using a material of good castability, with the base member as an insert. The rotor can be manufactured inexpensively and has the same characteristics as a rotor made from low-carbon-made steel.

Abstract: Motor for commercial and industrial applications such as golf carts and lift trucks. Features include a thin shell; stator; stator winding; and rotor. Rotor laminations have equally circumferentially spaced semi-closed slots having area for receiving conductors, and the ratio of the number of rotor lamination slots to the rotor outer diameter (measured in inches) is greater than 14.0. In one construction, this ratio is about 15.75; the ratio of the outer diameter to the rotor slot length is from about 9.04 to about 9.16; and the ratio of rotor slot depth or length to rotor slot opening width is from about 10.8 to about 12.5. Cylindrical stator lamination has a given outer diameter and a certain bore diameter determined by the distance between opposing poles. Through-bolt holes are located in the yoke, proximate the outer periphery thereof, and centered with respect to each pole. The ratio of stator pole neck minimum width to two times the yoke thickness or width is from about 0.809 to about 1.009.

Abstract: Axially elongated drive modules are interconnected at their opposite ends angularly spaced supports in a polygonal arrangement on an inner ring to establish tensile stress therein, while intermediate module centers are spaced from an inner shaft by solenoid locks. Each module includes at least two magnetostrictive rod elements held in axial alignment at their adjacent ends by a coupling, through which the module is radially spaced from the common axis. Drive coils electrically energized to generate magnetic fields cause simultaneous elongation and contraction of the rod elements to apply unidirectional torque to a rotor formed by either the outer ring or the inner shaft.

Abstract: A circuit breaker mounting section is provided for mounting a circuit breaker to a brush holder assembly in an electric motor. The mounting section is partitioned and formed so as to surround three sides of a circuit breaker with a partition wall projecting from the base plate of the brush holder assembly in a direction parallel to the axis of a motor core projecting through the assembly such that the outer surface side of the circuit breaker mounting section is open. The outer surface side opening of the breaker mounting section is surrounded and sealed by an inner side surface of a frame when the brush holder assembly is fitted and mounted in the frame.

Abstract: A limited angle torque actuator produces a substantially constant torque over an excursion angle of 90 degrees or more. The actuator uses a core made from a highly permeable magnetic material such as soft iron. In a preferred embodiment, one or more permanent magnets are attached to the outer surface of the cylindrical core. In another embodiment, the permanent magnets are spaced apart from a stationary core to create an air gap therebetween. When current flows through a coil wound on the stator, first and second stator poles are created which interact with the permanent magnets to rotate the rotor assembly.

Abstract: A homopolar actuator has a permanent magnet disk element rotatably positioned between a pair of toothed pole pieces with mutually offset teeth, an electromagnetic coil and pole elements coupling the coil flux to the pole pieces. The pole pieces may themselves be rotatable or stationary. The permanent magnet circuit attempts to center the disk element relative to the pole pieces, and the electromagnetic circuit, depending on the direction of current in the coil, either reinforces the centering action or overcomes the centering force to displace the elements from center position. The device is used as a two or three position actuator or as an actuator or magnetic spring operating against an external force and seeking a position as a function of current.

Abstract: A rotor of a permanent magnet type synchronous motor facing a stator having a number of slots comprises a rotor core fixed to a motor shaft and an even number of permanent magnets in a circumferential direction of the rotor core. Projecting portions are formed in the shape of a protruding portion of the rotor core over each permanent magnet. The width (A) of each projecting portion is different from the pitch (B) of the slots of the stator. A position detector for detecting the permanent magnet position of the rotor comprises detectors of the normal rotation and other detectors of the reverse rotation. These detectors are arranged having predetermined phase differences (.alpha., .beta.) to a center line. A pattern generating circuit is provided for switching the conducting position to the stator winding corresponding to the phase differences.

Abstract: A pricisely dimensioned gap between relatively movable surfaces (14,16) is maintained in a magnetic bearing by use of proximity sensors (22a, 22b, 23a, 23b). Each sensor includes a magnetic assembly (32) having a bar core (36) secured to a middle leg (42) of an F-shaped core (34). The bar core and the vertical leg (38) of the F-shaped core have approximately equal lengths. The magnetic assembly is fixed with respect to one of the surfaces (16) and is so positioned that the end (52,54) of the F-core vertical leg (38) and the bar core are spaced from the other surface (14) to provide the variable gap dimension. The end (48) of the suppermost leg (40) of the F-shaped core is spaced from the bar core and provides a reference dimension (44). Any differences in the variable gap and reference dimensions are furnished to a driver (27, 72-86) which moves one surface with respect to the other until the gap dimension corresponds to the reference dimension.

Abstract: A flat coreless vibrator motor includes a casing for housing the motor, a shaft rotatably supported by the casing, a rotor mounted on the shaft and being generally in the shape of a sector, the shaft being disposed at the center of a circle, along which a generally arc-shaped outer periphery of the sector generally extends. At least three armature coils are provided on the rotor and are angularly arranged in such a manner that these armature coils do not overlap each other. A magnet is mounted on the casing so as to generate a magnetic flux. A commutator and brushes cooperate with each other to supply electric power to the armature coils. Since the rotor is eccentric, vibrations are produced during the rotation of the rotor.

Abstract: A canned electric motor in which the stator is a laminated plate assembly which surrounds the can and the windings project beyond the laminated plate assembly on both sides. The bottom of the can at the end opposite that from which the motor shaft projects is curved outward and the windings bear on the outside of the can against the curved surface of the bottom.

Abstract: A magnetic fluid bearing may include a sleeve provided with a through bore, a shaft inserted into the bore, electromagnets engaged with the bore of the sleeve with a gap provided between the shaft and the electromagnets, a magnetic fluid introduced into the gap between the electromagnets and the shaft, and a controller for modifying the magnetic force of the electromagnets in accordance with changes in a load condition of the bearing. One or more electromagnets for radial loads may be engaged with the sides of the bore and an electromagnet for thrust loads may be engaged with a bottom of the bore. The controller has a sensor to detect changes in an inductance or capacitance that are indicative of the position of the shaft. The controller translates the changes into signals and transmits the signals to a power amplifier to modify the position of the shaft by changing the rate of electric current running through the electromagnets.

Abstract: An absolute position detector for detecting an absolute position of a rotating shaft (1) includes a rotatable shaft and first gearing for operatively coupling the rotating shaft to the rotatable shaft (3a). Resolvers are provided, each having a stator and a rotor. The stator includes pole teeth made of a magnetic material and arranged along an outer circumference of the rotating shaft at a distance from the rotating shaft. The rotor includes a rotor made of a magnetic material respectively associated with pole teeth and located between the rotating shaft and pole teeth. Second gearing operatively couples the rotor of the resolvers to the rotatable shaft. Upon a rotation of the rotating shaft, the first gearing causes the rotatable shaft to rotate, and upon a rotation of the rotatable shaft, the second gearing (14 and 15) causes the rotor of each of the resolvers, at incrementally different gear ratios, to vary reluctance of a magnetic circuit formed by the pole teeth of an associated stator portion.

Abstract: A viscous clutch (10) is typically employed in a fan drive mechanism within a truck or automobile. A shaft (18), driven by the engine (12), rotates a clutch member (42) within the fan drive. The clutch member is arranged for fluid engagement with a body member (60) for the transmission of torque thereto when fluid is disposed in an operating chamber (100) defined by complementary shear surfaces in the clutch and body members (48,98), respectively. An actuator assembly (30) operates to displace a valving element (196) within the clutch to control the torque transmission therethrough and thus the speed of the output shaft and fan (34) thereof. The actuator is electrically powered by a generator (222) made up of an armature (224) carried by the body member and a plurality of field generating magnets carried by clutch member (42) for rotational interaction therebetween.

Abstract: A brushless dc motor comprising a stator, and a rotor incorporating a hollow cylindrical permanent magnet. The rotor magnet has sectors magnetized radially in opposite directions to define poles of opposite polarity extending around the circumference of the magnet. The magnet is completely magnetized so as to leave no non-magnetized sectors between the poles of the magnet. The magnet has grooves in its surface facing the stator, the grooves extending in the longitudinal direction of the magnet. Each groove is offset from, or non-symmetrical with respect to, the center of the rotor pole in which it is located.

Abstract: A solid rotor for a dynamoelectric machine including field conductors and ventilation passages in axial slots is provided with low resistivity thermally conductive axial winged inserts which seal and overlie the slots to form a low resistivity cylinder about the rotor to minimize power losses and associated heating due to harmonic induced eddy currents, enhance the conductive cooling of the rotor, and increase efficiency.

Abstract: A compact motor mount for cassette drive systems includes a base plate in the form of a laminate that includes at least one planar layer of ferromagnetic material sandwiched between two printed circuit boards. A capstan motor is supported by the base plate. The stator coil assembly of the capstan motor is mounted on one side of the base plate directly on one of the two printed circuit boards. At least one winding drive motor also is supported in common with the capstan motor by the base plate. The stator coil assembly of the drive motor is mounted on the other side of the base plate directly on the second of the two printed circuit boards. Each of the motors has a permanent magnet rotor mounted on a shaft and facing the respective stator coil assemblies across an air gap defined therebetween.

Abstract: A drive mechanism is redundantly equipped with two electric motors so that the second motor can take over the drive function if the first motor should fail, for example for moving equipment in or on a spacecraft. Both electric motors are connected to a common drive shaft. A coupling device makes sure that the defective motor is decoupled from the drive train.

Abstract: The reduction gear (6) is fastened to the body (1) of an electric motor including a gear, and the motor stator is fastened to the removable electronics part (13) of the body. The motor rotor (7) is connected to the gear with an input shaft (15), the output shaft (20) extending concentrically through the input shaft. The output shaft (20) is carried in bearings (3, 4) essentially near the end faces of the housing (1, 13). One end of the output shaft constitutes a flange-shaped cover (2) of the gear, the flange being carried in a bearing (3) close to the outer periphery of the housing. The gear can be realized as a friction gear with several stages.

Abstract: A disc-type motor characterized by increased efficiency includes first and second parallel spaced stator members made of magnetic material in fixed relation, each of the stator members having a flat circular shape and an even plurality of pie-shaped permanent-magnet poles thereon, illustratively eight in number. The facing poles on the stator members have opposite polarities. The motor further includes a disc-like rotor made of a non-conducting material rotatably mounted between the two stator members. Conducting wires are wound in a non-overlapping (single-layer) flat spiral configuration to form a number of coils equal to twice the number of poles per stator member, half adhered to each face of the rotor disc. Each coil encloses a pie-segmented area about equal to the area of one of the stator poles. On each face of the rotor the coils magnetically oppose one another, and the coils on one face of the disc are angularly offset from the coils on the other face of the disc.