Abstract: A disk memory drive includes a brushless drive outer rotor motor having an internal space and a stator with windings. The outer rotor coaxially encircles the stator and a substantially cylindrical air gap is defined between the stator and the rotor. The rotor includes permanent magnets and a hub fixedly connected with the magnet. A disk mounting section is provided on the hub for accommodating at least one storage disk positioned in a clear space, the mounting section being adapted to extend through a central aperture of the storage disk. The windings and the magnets interacting with the windings are disposed for at least half of the axial longitudinal dimension thereof within a space surrounded by the disk mounting section of the hub. Bearings rotatably mount the rotor and the hub.

Abstract: A permanent magnet excited motor is provided with a plurality of low circumferential hump-like protrusions on the face of each stator pole to partially decrease the air gap between the stator and rotor and act as so-called magnetic cams to exert a force on the rotor to smooth an otherwise uneven parasitic slot torque that occurs between the interaction of slot openings of the stator poles and the gaps between the permanent magnet poles of the rotor.

Abstract: A composite printed circuit board having a metallic layer supporting body with a first insulating layer thereon and wherein the insulating layer has copper printed circuits placed thereon. The printed circuit board is adapted to precisely hold and position electric components (normally electrical motor sensors) on stamped out recesses in the composite body. The stamped out recesses have edge portions for finitely positioning the components and allow for electric leads coming from the components to pass over the bent tabular portion of the recess to be soldered to the copper circuits.

Abstract: The present invention relates to an integrated driving system for signal-processing devices, especially video devices (recorders) and other, preferably magnetic pulse recording devices, wherein the device chassis (1) and the mounting provision for at least two motors (20, 21, 22) are formed integrally with each other. The device chassis (1) proper also includes all mounting or bearing bores (e.g. 2, 50, 55) for all mounting shafts (e.g. 4, 8, 18) in a precise positional relation to each other. The bores (2, 50, 55) for all mounting shafts (4, 8, 18) and axles are formed in the metal-cast device chassis (1) in one or more machining operations without the necessity of re-chucking, ensuring that not only the active and passive driving sections of the driving system, but also the reference surfaces and bearing or supporting points are preceisely positioned relative to each other.

Abstract: A circuit arrangement for generating a useful direct voltage signal associated with the frequency of an alternating current signal serves, in particular, to regulate the synchronism of an electric motor. It includes a comparator circuit (7) which converts the two opposite polarity half-waves of the alternating current signal of a tacho coil (2) into pulses whose edges trigger a measuring and control circuit (18) which generates direct voltages corresponding to the half-period durations of the alternating current signal measured from the respective zero passages.

Abstract: A method is disclosed for the low-loss regulation of a d.c. motor without commutator and of a semiconductor circuit in which, during a commutation phase at reduced motor power or rpm as given by a position indicator, the end transistors or one end transistor initially operates temporarily as a switch and thereafter temporarily as an analog amplifier element. During the analog period, a current is available which changes slowly according to a ramp function.

Abstract: A disk storage has one or more disks provided with center holes. An electric motor extends coaxially through these holes and has an external rotor to the outer circumference of which the disks are secured so that they rotate with the rotor. A seal is provided for at least reducing the escape of contaminants from the motor.

Abstract: A step motor which, in addition to an exciter system for step-by-step movement, is provided with an axial exciter system. As a result of the direct or indirect influence of the magnetic field generated by the secondary exciter system on the rotor which is supported, so as to be able to move in an axial direction with respect to the stator, the rotor can be induced to move in a direction perpendicular to its step-by-step rotary motion, as well. Both exciter systems can be energized independently of one another, so that step-by-step rotary movement can be performed at any axial position of the rotor and the rotor can be made to move in an axial direction during its rotary movement as well as when it is at rest.

Abstract: A fan is disclosed comprising an electric drive motor having a shaft with an impeller coaxially disposed thereon, the impeller configured to suck axially and to blow with radial directional components and including a hub which is turned down over the motor, the hub having a rearward broad end that is turned away from the flow and presenting an outer generated surface that is symmetrical in rotation with reference to the motor axis, the outer generated surface being widened like a funnel in the direction of flow and inwardly defining an annular flow passage, and wherein blades are fastened to the hub along the generated surface. Further, in the disclosed fan the outer edges of the blades extend along a surface of rotation that is coaxial to the axis of the motor, the surface of rotation being constantly widened in the flow direction like a funnel, the widenings of the generated surface and the surface of rotation at least preponderantly having an opening angle that is less than 90.degree.

Abstract: A drive unit for direct drive of an information-storage disk comprises a brushless dc external-rotor motor having a permanent-magnet rotor magnet arrangement of considerably reduced axial length. Electrostatic charge is removed from the rotor shaft by a metallic spring element which engages the shaft periphery from within the interior of the rotor housing. An electromagnetic braking arrangement is located interiorly of the housing. The packet of stator plates for the stator has an axial length shorter than that of the rotor magnet arrangement, but is provided at its axial end faces with skirted-rim flux-conducting elements whose peripheral skirt portions form useful-air-gap extensions in cooperation with the rotor magnet arrangement.

Abstract: A disk memory drive includes a brushless drive outer rotor motor having an internal space and a stator with windings. The outer rotor coaxially encircles the stator and a substantially cylindrical air gap is defined between the stator and the rotor. The rotor includes permanent magnets and a hub fixedly connected with the magnet. A disk mounting section is provided on the hub for accommodating at least one storage disk positioned in a clear space, the mounting section being adapted to extend through a central aperture of the storage disk. The windings and the magnets interacting with the windings are disposed for at least half of the axial longitudinal dimension thereof within a space surrounded by the disk mounting section of the hub. Bearings rotatably mount the rotor and the hub.

Abstract: Collectorless (brushless) three-phase DC motor having a permanent-magnet arrangement and a three-phase winding, these being movable relative to each other, and having three position sensors which are stationary relative to the winding and controlled by the permanent-magnet arrangement to supply sensor output signals. The winding's coils are energized by current in a cyclical sequence in dependence upon the sensor output signals, the latter being offset by 120.degree.-el. one from the next. Induced coil voltages are offset by 120.degree.-el.; the coil voltages, in crossing zero, are alternately positive for at most 180.degree.-el. and negative for at most 180.degree.-el. and their sum is equal to zero for all relative positions as between the magnet arrangement and the winding. The position sensors are so arranged relative to the winding's coils that the sensors' changes-of-state substantially coincide with the zero-crossovers of the associated induced coil voltages.

Abstract: A disk memory drive includes a brushless drive outer rotor motor having an internal space and a stator with windings. The outer rotor coaxially encircles the stator and a substantially cylindrical air gap is defined between the stator and the rotor. The rotor includes permanent magnets and a hub. A disk mounting section is provided on the hub for accommodating at least one storage disk positioned in a clean chamber, the mounting section being adapted to extend through a central aperture of the storage disk. The windings and the magnets interacting with the windings are disposed for at least half of the axial extension thereof within a space surrounded by the disk mounting section of the hub. Bearings rotatably mount the rotor and the hub.

Abstract: A circuit arrangement for generating a useful direct voltage signal associated with the frequency of an alternating current signal serves, in particular, to regulate the synchronism of an electric motor. It includes a comparator circuit (7) which converts the two opposite polarity halfwaves of the alternating current signal of a tacho coil (2) into pulses whose edges trigger a measuring and control circuit (18) which generates direct voltages corresponding to the half-period durations of the alternating current signal measured from the respective zero passages.

Abstract: A method for the low-loss regulation of a collectorless direct current motor and a semiconductor circuit has, during the commutation phase given by a position sensor and with reduced motor output and number of revolutions, transistors or one end transistor which initially operates temporarily as a switch and thereafter operates temporarily as an analog amplifier element. During the analog period, a current is available which changes slowly according to a ramp function.

Abstract: A small fan which is constructed as compact axial fan with a central driving motor retained by way of a flange and a bearing support tube, and in which the housing of the fan forms a flow duct that surrounds the rotor; the bearing support of the shaft of the driving motor is constructed as one-piece slide bearing unit which is secured radially in an axial partial area of the bearing support tube by a sliding seat; the bearing support tube consists of a material which can be injection-molded.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. The rotor includes a permanent magnet and a soft magnetic yoke. A hub is provided that is concentric to the yoke and is connected to the rotor for rotation therewith. The hub has a disk mounting portion on its outer peripheral surface that can be passed through the central opening of a standardized storage disk for mounting the storage disks for rotation therewith. At least half of the axial longitudinal dimension of the stator winding and the rotor magnet interacting therewith is housed within the disk mounting portion of the hub. The hub is made from a non-ferromagnetic material that is suitable for storage drive clean chamber use after dimensional finishing of the hub.

Abstract: Designed especially for hand-held dictation devices the motor has a three-phase external stator and two-pole permanent-magnet internal rotor, the two enclosed by an external housing from one axial end of which the rotor shaft projects out, its other axial end provided with a thrust bearing for the rotor shaft's other end. At least one Hall element, although more typically three, is provided, located at the peripheral edge of one of the axial ends of the rotor to sense axially emanating stray rotor flux. The rotor is directly secured to the rotor shaft, the shaft being ferromagnetic and near its outwardly projecting end provided with a ferromagnetic bearing mounted in a ferromagnetic end plate, so that stray flux sensed by the Hall element can travel from the rotor to the Hall element along a magnetic circuit for such sensed stray flux, but with the magnetic circuit being made up of motor components and structural parts that are required anyway.

Abstract: An improved motor assembly including a brushless D.C. motor and an annular member defining a platform for the drive electronics and speed control circuits of the motor. The member is carried on a fixed support within the outer envelope of the motor and includes a thin disk-like body providing a pair of opposed surfaces for mounting the components of the circuits. The fixed support of the motor has a flat annular face surrounding the drive shaft of the motor, and the annular member engages and is secured to the flat face of the support in surrounding relationship to the shaft. In a preferred embodiment, the housing of the motor defines part of the rotor of the motor and is for rotation with the shaft. A flange is secured to the support near the opposite end of the shaft for mounting the motor on a fixed support, such as on the base of a housing forming a part of a disk drive unit.

Abstract: A circuit for speed monitoring, particularly for fan drives. A detection device for producing an input signal sequence is provided which has a speed-dependent repetition frequency. The circuit also has a signal converter for converting the input signal sequence into an output signal whose amplitude is a function of the repetition frequency of the input signal sequence. There is also an evaluation circuit, having at least one threshold value element responsive to the output signal of the signal converter and which responds if the output signal amplitude reaches a value corresponding to a drop below a predetermined minimum speed or a rise above a predetermined maximum speed.