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 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: To lessen mounting time and to optimize positioning of the Hall generator, the Hall generator and control electronics influenced by the generator so as to actuate a brushless dc motor are arranged on a common substrate and are provided with a common protective envelope whose dimensions are somewhat narrower than the cross-section of the motor slot. This substrate is inserted in the motor slot so that the Hall generator is located outside the slot and in the effective magnetic field of the motor's permanent magnet.

Abstract: Device for a drive for storage media for the generation of at least one index pulse per revolution of a rotating element with a generator, which, during operation, for each revolution of the rotating component, generates at least one signal pulse that alternates once between two polarities, and with an evaluating circuit activated by these alternating signal pulses to generate the index pulses at its output. The evaluating circuit includes a comparator with asymmetrical hysteresis with two inputs and one output, between the two inputs of which comparator the output signal of the generator lies, and the hysteresis of which is tuned to the generator output signal such that the comparator output sharply changes from a first to a second potential when the amplitude of the signal pulse at a preset polarity exceeds a preset switching voltage value, and sharply returns from the second to the first potential when the signal pulse passes through its zero crossing from the preset to the opposite polarity.

Abstract: Electric motor with a substantially cylindrical air gap between the stator and the rotor, the stator being fitted to a bearing support for the rotor shaft bearing. In order to reduce noise emissions, the stator is connected to the bearing support by means of an elastic damper and the stator and bearing support are separated from one another by an air gap adjacent at least part of their facing faces.

Abstract: In line DC motor with a permanent magnet arrangement displaying a ferromagnetic ground and a multi-strand winding, which are linearly moveable with respect to one another, in particular for drives in data engineering. The winding consists of several coils following one another in the direction of movement, activatable with current in cyclic sequence, which in each case are layed without overlap around a pole of at least one grooved flow guidance part which together with the permanent magnet arrangement forms an essentially even air gap, with coil axis standing perpendicular to the direction of movement. The ratio of coil interval to magnet interval amounts to 2:3. To make interfering reluctance forces ineffective, in the vicinity of the sides of the end poles lying in the direction of movement, ferromagnetic auxilliary poles are provided.

Abstract: A direct current linear motor, particularly for use in data processing drive systems, is provided. The motor includes a plurality of permanent magnet poles disposed linearly adjacent each other, a ferromagnetic structure having a multi-strand winding formed of a plurality of coils, each strand forming a coil, the permanent magnet poles and the ferromagnetic structure being linearly moveable relative to each other. A flat air gap is defined between and separates the permanent magnet poles and the ferromatic structure. The ratio of the coil pitch of the ferromatic structure to the magnetic poles of the permanent magnet system is not greater than 1.

Abstract: A driving mechanism for magnetic hard disc memories includes an isolated space for maximum cleanness from the remainder of the apparatus, a driving motor mounted within the apparatus and having a stator and a rotor, the motor when energized having parts producing magnetic flux, a hub extending into the space of maximum cleanness for receiving therein at least one magnetic hard memory disc, a connection between the motor and the hub for driving the hub, and a magnetic flux shield located between the parts producing the magnetic flux and the space of maximum cleanness.

Abstract: Drive for signal processing equipment includes a direct drive brushless D.C. motor having a rotor with a permanent magnet formed of at least two pairs of poles and an additional magnet creating a flux discontinuity in the form of a field strength increase, at least one stationary magnetic field sensor, a commutating signal generator stage, a commutating device and a stator winding, and an index signal generator stage that generates one index signal per rotor rotation in response to the flux discontinuity. The commutating signal generator stage is provided with a commutating comparator connected to the magnetic field sensor output, and its two switching points are located close to the portion of the magnetic field sensor output signal not affected by the increased field strength. The index signal generator stage has an index comparator having one switching point located close to the portion of the magnetic field sensor output signal that corresponds to the field strength increase.

Abstract: An internal flux-conducting member is axially elongated and is manufactured with at least one radially extending electrical discontinuity, to prevent circumferential eddy currents from flowing therewithin in paths which are circular as viewed along its axis. The member may be a single unitary element into which elongated slots are cut, or may be assembled of a plurality of like rods which, when assembled together, have abutting surfaces which form the electrical discontinuities. The rods may be joined together by a nonconductive metal-bonding agent.An external flux-conducting member is disclosed in which at least two like curved frame elements which are made of ferromagnetic material are connected together so as to form a hollow, open-ended frame with an axially elongated and generally cylindrical shape. The frame thus formed contains a plurality of annular magnet rings which are all radially magnetized, with adjacent magnet rings being magnetized in opposite direction.

Abstract: A driving mechanism for magnetic hard disc memories includes an isolated space for maximum cleanness, a driving motor mounted within the apparatus and having a stator and a rotor, the motor when energized having parts producing magnetic flux, a hub extending into the space of maximum cleanness for receiving therein at least one magnetic hard memory disc, a connection between the motor and the hub for driving the hub, a magnetic flux shield located between the parts producing the magnetic flux and the space of maximum cleanness, and the rotor being detachably connected to the rotor shaft.

Abstract: To prevent damage to magnetic storage disks from sliding of the magnetic heads over the disk surface during running-out of the disk to a stop, the disk is positively braked when its drive is de-energized, so as to shorten the running-out time.

Abstract: A first capacitor is discharged with every pulse of a train of pulses of a frequency proportional to the actual speed of a rotary machine under control and is charged up during intervals between these pulses. The voltage of the first capacitor provides a signal to a threshold circuit which operates to provide a second signal whenever the voltage of the first capacitor exceeds a predetermined voltage which may be set in order to set the speed at which the machine is to be controlled. During the presence of the second signal a second capacitor is charged, beginning at a predetermined voltage, preferably zero. The regulating magnitude for the machine to be controlled is derived from the voltage of the second capacitor either directly or indirectly through a controller circuit and a power stage. The circuit is particularly useful for control of the speed of machines that run slowly or can conveniently provide only relatively few speed-indicating pulses per revolution.

Abstract: In response to a Hall-IC sensor exposed to the magnetic field of the rotor of a brushless d.c. motor, two interleaved sequences of pulses are generated at separate outputs with an interpulse pause of a certain length occurring between successive interleaved pulses to prevent reduction of efficiency and increase of motor noise that would result from overlapping pulses being supplied to the stator of the motor. When these pulses are utilized to switch a semiconductor full bridge circuit, through which a single winding of the stator is energized by current pulses alternating in direction, prevention of short-circuits resulting from slow turn-off of the semiconductor switches is prevented. For overcurrent protection, only half of the bridge is intermittently blocked by a current regulator when the current reaches a predetermined limiting value, this provision also reducing generation of noise and interference by the motor.

Abstract: A linear motor unit includes a stator having on outer flux-carrying structure and an inner flux-carrying structure, and an armature arranged for travel along the length of the inner flux-carrying structure. The inner flux-carrying structure comprises an elongated rod. The armature slidably positioned along these rods carries a number of coils spaced one from another in the direction of elongation of the rod and surrounding the rod. A plurality of sets of permanent magnets are concentrically positioned within the outer flux-carrying structure which is arranged in a form of two tubular elongated members. The permanent magnets in each set are radially positioned with respect to the rods and located one opposite to another. Preferably successive ones of the sets of magnets have an alternate polarity. The coils are energized periodically and in a cyclical sequence to provide a motive force for the movement of armature along the parallel rods.

Abstract: A first capacitor is discharged with every pulse of a train of pulses of a frequency proportional to the actual speed of a rotary machine under control and is charged up during intervals between these pulses. The voltage of the first capacitor provides a signal to a threshold circuit which operates to provide a second signal whenever the voltage of the first capacitor exceeds a predetermined voltage which may be set in order to set the speed at which the machine is to be controlled. During the presence of the second signal a second capacitor is charged, beginning at a predetermined voltage, preferably zero. The regulating magnitude for the machine to be controlled is derived from the voltage of the second capacitor either directly or indirectly through a controller circuit and a power stage. The circuit is particularly useful for control of the speed of machines that run slowly or can conveniently provide only relatively few speed-indicating pulses per revolution.

Abstract: The linear motor comprises a stator and an armature mounted for travel along the length of the stator. The stator includes an elongated inner flux-carrying structure extending in the direction of armature travel. A plurality of stationary coils are provided on the inner flux-carrying structure, the stationary coils being spaced in the direction of armature travel. The armature is provided with a plurality of radially magnetized permanent magnet units spaced in the direction of armature travel. The magnetic polarity of successive ones of the permanent magnet units alternates, proceeding in the direction of armature travel from one permanent magnet unit to the next. An outer flux-carrying structure, provided on either the stator or armature, extends in the direction of armature travel and surrounds the armature.

Abstract: A positioning motor is energized by an actuating signal which includes a component proportional to, and another component proportional to the time-derivative of the output signal of a displacement transducer. The displacement transducer includes a plurality of light detectors. A synchronizing structure coupled to the motor moves through the light paths of the light detectors, causing each to generate a respective one of a plurality of mutually phase-shifted first signal components. Signal-processing circuitry derives from the first signal components second signal components which are phase-shifted relative to the first signal components, and combines the first and second signal components to form the transducer output signal.

Abstract: The stator comprises a ferromagnetic structure including a pair of spaced parallel ferromagnetic bars. A row of magnets extends along the length of the bars, at the inner side of one of the bars. The individual magnets of the row are magnetized in a direction transverse to the elongation of the bars. The successive magnets of the row are of alternate polarity. An armature is mounted for travel along the length of the two bars and includes a plurality of coils spaced one from the next in the direction of elongation of the bars and oriented to cut through the magnetic field lines of the magnets of the row of magnets in the space intermediate the two bars. The armature coils are energized periodically and in a cyclical sequence causing the armature to travel along the length of the two bars.