Abstract: In a two-conductor, two-pulse brushless d.c. motor (10) driver transistors (44, 45) are provided for the end-stage transistors (52, 53) and are connected at a control electrode thereof to a potential (point 47) which, e.g., amounts to half the supplied d.c. voltage. These driver transistors are activated by a Hall-IC (32) having a digital signal (41). In order to avoid an abrupt switchover from one conductor (25) to the other conductor (26), each driver transistor (44, 45) has its own RC-stage (43', 46' or 43", 46"). In this way one produces currentless gaps between successive stator-current pulses and implements a relatively soft switching of the end-stage transistors, so that the motor is caused to run quietly.

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 bearing assembly for an axially compact miniature motor or ventilator, wherein a sintered friction bearing unit (15) for the motor of a rotary shaft (1) of the drive motor (13) is clamped between a shoulder (6') of a bearing support tube (5) and another shoulder (7) of a closure element (8) cooperating with the bearing support tube (5).

Abstract: A one-phase motor has two conductors energized alternately via respective pnp and npn transistors and from the same output of a Hall-IC, without polarity inversion. When the Hall signal goes high the first transistor goes conductive and the second non-conductive, or vice versa. Capacitive delay elements slow down the switching-ON and -OFF of the two transistors. The capacitive delay elements have the undesired effect that, in response to the self-same change in the value of the Hall signal, the signal at the base of the OFF transistor changes comparatively quickly to switch the same ON, whereas the signal at the base of the ON transistor changes comparatively slowly to switch the latter off, which can lead to both being briefly conductive simultaneously, leading to voltage spikes and precluding safe dissipation of inductive energy in the transistors themselves.

Abstract: An axial-flow fan, particularly a small fan which is axially compact, with a scroll plate surrounding the impeller and whose inner contour has a cylindrical configuration in the vicinity of the axial median plane and extends both towards the inlet side and the outlet side in a polygonal, particularly square profile accompanied by the formation of corner areas, and with a central, coaxial core formed by the drive motor, the impeller hub and the mounting flange for the drive motor; the core thereby has an annular surface conically tapering towards the inlet side face whose axial length is at least one-third of the hub length; with respect to the axial median plane, the scroll plate is asymmetrical in the corner areas and is made cylindrical over a longer distance from the axial median plane to the inlet side than to the outlet side.

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: The invention provides a two-pulse brushless direct current motor with reluctance auxiliary torque. The rotor has an approximately trapezoidal magnetization with small gaps between the poles. These gaps are positioned so that they come to rest opposite the point of largest air gap when the motor is deenergized. The motor has a high starting torque from this position of the rotor.

Abstract: In an axial fan whose fan wheel is retained in a tubular member by spokes, the blade edges of the individual fan blades which face the spokes are constructed geometrically different from one another.

Abstract: A mounting arrangement for connecting strand connectors to a stator winding of an electric motor utilizes axially aligned pockets in an end mounting plate of the stator, into which the connectors are inserted. A cover plate is then lockedly mounted onto a control portion of the end mounting plate, and together with the end plate defines a tortuous path for the strand connectors, wherein the connectors axially leaving the pockets are first bent radially outward, then bent back to the original axial direction and then bent radially outwardly again. This tortuous bending path provides for strain elimination at the point of connection of the connectors to the stator inside the pockets.

Abstract: An actuation circuit for direct current motors without collectors having at least one analogously operating galvanomagnetic sensor, of the Hall generator type which serves to control the currents in at least two end stage transistors. At least two differential amplifier stages having a high voltage gain and a high input resistance feed the amplified output signal of the galvanomagnetic sensor to the end stage transistors. Ohmic voltage dividers are provided for generating time pauses between the "on" states of the end stage transistors, these ohmic voltage dividers utilizing part of the voltage between the control terminals of the at least one galvanomagnetic sensor to form switching thresholds for the at least two differential amplifier stages.

Abstract: In the case of a two-pulse brushless d.c. motor narrow auxiliary poles (81-84; 115-122) are provided in the region of the boundaries (44, 45) between neighboring main poles of the rotor, the auxiliary poles being at least in part of polarity opposite to that of the surrounding main poles of the rotor. As a result of this, one obtains an especially favorable functional dependence of the induced voltage upon rotor angular position.

Abstract: The stators of collectorless d.c. motors are securely connected with the bearing support member, and/or with the fastening flange. The printed circuit board with the electronic components for the commutation is arranged for space reasons in collectorless d.c. motors between the fastening flange and the stator. This type of construction makes impossible an exchange of, for example, defective components. According to this invention, a removable stator is proposed which is retained and secured by means of only a spring element.

Abstract: A drive unit for direct drive of an information-storage disk comprises a collectorless D.C. 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 small motor having a planar air gap has a rotor comprising a rotor shaft journalled in a carrier pipe of small diameter at whose outer periphery are mounted shape-retaining rotor coils which are cantilevered out into the air gap. This provides a rotor of very small axial moment of inertia, affording very short start-up times. The printed circuit collector has lamella-group connectors on both sides of the substrate. Such a motor is suitable especially for signal-recording or -reproducing apparatus. The arrangement of the rotor coils is symmetrical and yields a very simple and compact motor construction.

Abstract: Disclosed is an arrangement for providing an electrical connection to the enamelled wire of a coil of an electrical motor. The arrangement includes a circuit board carrying at least one conductive component such as an electrical trace on the surface of the circuit board. A conductive pin-type contact, also carried by the circuit board, is electrically connected to the conductive component. An insulating body is carried by the electrical motor and includes passageways for receiving at least two pin-receiving receptacle terminals. The receptacle terminals have inwardly-extending rib members for engaging the enamelled wire when the enamelled wire and the pin-type contact are inserted therein. The rib members are operative to penetrate the enamel covering to establish electrical contact with the wire.

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: When the motor's permanent-magnet rotor is in a first range of angular positions a stator-winding phase is energized to have a first magnetic polarity, and to have an opposite second polarity when the rotor is in a second range of angular positions. The rotor angular position is sensed by a magnetic-field-sensitive semiconductor element, especially a Hall generator, responsive to the field from the permanent-magnet rotor. When the rotor is in a range of angular positions between such first and second ranges, all power transistors are rendered non-conductive, by control signals derived from the magnetic-field-sensitive semiconductor element by intermediate circuitry, to render the stator-winding phase currentless during the time interval within which commutation is to occur.