Papst-motoren Gmbh & Co Kg

Papst-motoren Kg

Papst Licensing Gmbh

Other

Mathias Bauerle Gmbh

Papst Licencing Gmbh

Rolf Muller

Johann Von Der Heide

Alfred Merkle

Georg F Papst

Gunter Wrobel

Benno Doemen

Siegfried Harmsen

Dieter Elsaesser

Volker Schlicker

Hans-Martin Baumann

Georg Moosmann

Fritz Schmider

Heinrich Cap

Dieter Elsasser

Horst Purr

Hermann Raible

Dieter Otto

Manfred Kistler

Helmut Moosmann

Heinrich Kochendorfer

Cornelio Leonardi

Egbert Backe

Ewald Walker

Rudi Rommel

Paul Fussner

Reinhold Wurdak

Ernst-Moritz Korner

A three-phase brushless dc motor includes a permanent-magnet rotor magnet arrangement having at least four poles and a Y-connected, or star-connected, three-phase stator winding. The winding's phases are arranged non-overlapping in slots of a slotted stator, the currents flowing in the three phases being controlled via at least three semiconductor elements by at least three magnetic-field-sensitive rotor position sensors. Each sensor is associated with a respective two of the winding's three phases and triggers a commutation which switches off the current in one of the associated two phases and switches on the current in the other of the associated two phases. The sensors are located to sense the permanent-magnet flux emanating from the rotor poles themselves. The rotor position sensors are provided at special angular locations on the stator. Each sensor is provided at an angular location at which there is not to be found, neither prior to nor subsequent to the commutation associated with that sensor, any energized stator pole; this may mean that the sensor location is (i) an angular location at which no energizable stator pole whatever is present, and it may mean that the sensor location is (ii) an angular location at which an energizable stator pole is in fact present, but during motor operation this energizable stator pole is in an unenergized state prior to a commutation associated with the particular sensor in question and likewise is in unenergized state subsequent to that commutation.

Brushless three-phase dc motor

A disk storage device including a housing surrounding a clean chamber, at least one storage disk having a central opening, at least one data head mounted on the housing for movement in operative relationship with the disk within the clean chamber, and motor elements for rotating the disk within the clean chamber. The motor elements include a rotatable member positioned within the clean chamber. The rotatable member has a cylindrical outer surface portion that extends into the central opening of the storage disk and is supported by a shaft and bearing system. A stator including magnetically active parts is mounted on a support member, which also supports the shaft and bearing system. The stator has a magnetic flux-producing section having poles positioned on the same side of the support member as the rotatable member. The rotatable member includes a cylindrically-shaped magnetic flux-producing and conducting element including a ferromagnetic ring and an annular permanent magnet spaced from the poles of the stator by a substantially cylindrical air gap. Further, the outside diameter of the cylindrically-shaped magnetic flux-producing and conducting element is larger than the diameter of the central opening of the storage disk.

Disk storage device, with hub and drive motor rotor features

A disc drive having a housing which encloses a clean room that is provided with a brushless DC drive motor having an external rotor and three pole shoes on a substantially ring-shaped stator for each two pole on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Disc drive having a brushless DC drive motor with an external rotor for

A brushless DC drive motor with an external rotor has three pole shoes on a substantially ring-shaped stator for each two poles on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Brushless DC drive motor with external rotor for use in disc drives and

A frequency to be monitored is taken to a counter for the continuous measurement of its cycle time. The counter is so set that, when this frequency drops, i.e. when its cycle time increases, it reaches a certain condition and issues error signals (flags) as long as the condition lasts. The first flag actuates a flip-flop which in turn actuates a timer (alarm counter) which, after a short time, triggers an alarm unless it has previously been stopped by the resetting of the flip-flop. The flags are also continuously sent to a second counter which is so arranged that it cannot reach a certain (high) condition in the interval between two successive flags for a continued condition of the first counter. If the frequency to be monitored becomes normal again, the flags disappear and the last flag occurring once again starts this second counter so that it rises to the preset (high) position and emits a reset signal. If the alarm has not yet been triggered, this reset signal can reset the flip-flop and thus cancel its actuated state. Thus the timer (alarm counter) is stopped and the triggering of an alarm is prevented.

Frequency monitoring device

A three-phase brushless dc motor includes a permanent-magnet rotor magnet arrangement having at least four poles and a Y-connected, or star-connected, three-phase stator winding. The winding's phases are arranged non-overlapping in slots of a slotted stator, the currents flowing in the three phases being controlled via at least three semiconductor elements by at least three magnetic-field-sensitive rotor position sensors. Each sensor is associated with a respective two of the winding's three phases and triggers a commutation which switches off the current in one of the associated two phases and switches on the current in the other of the associated two phases. The sensors are located to sense the permanent-magnet flux emanating from the rotor poles themselves. The rotor position sensors are provided at special angular locations on the stator. Each sensor is provided at an angular location at which there is not to be found, neither prior to nor subsequent to the commutation associated with that sensor, any energized stator pole; this may mean that the sensor location is (i) an angular location at which no energizable stator pole whatever is present, and it may mean that the sensor location is (ii) an angular location at which an energizable stator pole is in fact present, but during motor operation this energizable stator pole is in unenergized state prior to a commutation associated with the particular sensor in question and likewise is in unenergized state subsequent to that commutation.

Brushless three-phase DC motor

A tachogenerator for speed control of an electric motor including a stator and a rotor. A multipole permanent magnet is connected to the rotor and has at least a pair of magnetic poles, with the pole centers of the magnetic poles being uniformly arranged on a circle of a predetermined diameter. A wave winding is connected to the stator and separated from the magnet by an air gap having a width. The wave winding having angular repeat units of the wave winding equal to from 0.5 to 1.5 times a ratio of the diameter divided by the width.

Tachogenerator for speed control of electric motors

The stator winding of a brushless D.C. motor receives two current pulses per 360.degree.-el. of rotor rotation, each current pulse being furnished via a respective current path. Each current path contains at least one power transistor switch having conductive and non-conductive states. These states are determined by respective driver transistor switches; when the driver transistor switch is in a high-output-impedance state the respective power transistor switch is rendered conductive, but when in the low-output-impedance state it renders the power transistor switch non-conductive. In various ways disclosed herein measures are taken to prevent the power transistor switches of both current paths from being simultaneously conductive. This may be accomplished using inherent or discrete base-emitter capacitances so connected that a power transistor switch is switched off abruptly but switches-on only after the elapse of a predetermined delay. Alternatively, the Hall voltage produced by the motor's rotor-position-sensing Hall cell may be applied to comparators such that the power transistor switches are not even commanded to conduct except during respective periods each shorter than 180.degree.-el.

Brushless direct current motor

A circuit for controlling a d.c. motor (10) is provided with a current-limiting arrangement (27), designed as a time-delay amplifier, responding at a certain current value by interrupting the supply of current to the motor (10), and then after a certain time, determined e.g. by internal timing elements (46, 47, 49, 54), switching the current supply to the motor (10) on again. The switching operations occurring in such a motor, i.e., the pulse-duration/pulse-gap ratio and the pulse repetition frequency, are a function of the back-EMF that is induced in the motor (10) as a result of its rotation. This situation is exploited for the following purpose: to make the threshold value of the current-limiting arrangement high when the pulse-duration/pulse-gap ratio is high, namely e.g. when the application of current to the motor is practically continuous; and, in contrast thereto, to reduce this threshold value to, for example, one half when the pulse-duration/pulse-gap ratio is low, such as is characteristic when the motor is at a standstill and during start-up. In this way the motor, if blocked against rotation, draws power of a value substantially lower than at rated operation and, for this reason, cannot become overheated even if it is blocked against rotation, and during start-up no excessive values of start-up current can develop.

D.c. motor with a current-limiting arrangement

An axial flow fan for ventilating electrical and electronic equipment includes a brushless, DC external rotor-type central drive motor. The stator is supported by a bearing tube formed of plastic, which is connected together with a mounting flange to form a single piece.

Miniaturized direct current fan

An axial flow fan for ventilating electrical and electronic equipment includes a brushless, DC external rotor-type central drive motor. The stator is supported by a bearing tube formed of plastic, integrally molded with a mounting flange. In one embodiment, the fan casing forms part of the integral plastic molding.

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.

Growing community of inventors

St. Georgen, Germany

Rolf Muller