Abstract: A radial-blade double-inlet fan (1) which includes a casing (2) with two inlet openings (8,10) facing each other, an external electrical rotor motor (14) located in casing (2), having a stator (16) and a rotor (18), and of a radial impeller (20) which is connected to rotor (18) and which axially extends on both sides beyond motor (14) into the direction of inlet openings (8,10). To absorb the oscillations, motor (14) is flexibly supported by the casing. Stator (16) is connected to stator flange (32), and rotor (18) encloses stator (16) only along one side approximately up to stator flange (32).

Abstract: The invention relates to a drive unit for a double fan consisting of two external rotor motors (1, 2) arranged alongside each other on a common motor shaft (3), wherein the external rotor motors (1, 2) are arranged with respect to each other in such a way that the poles of the stators (12) of the two motors (1, 2) and the poles of the rotors (7) of the two motors lie in mirror image symmetry with respect to each other with reference to a dividing plane X--X running between the two external rotor motors (1, 2) at right angles to the motor shaft (3).

Abstract: An electric motor 2 with a stator 22 comprising a stator plate packet 24 and coils located in grooves of the stator plate packet 24, and a plug connector device 30 for connecting wire ends 32 of the coils 28 with motor connector leads 34. The plug connector device 30 has retaining elements 38 composed of insulating material and holding electrical connector elements 36. Each retaining element 38 is located in the region of one of the grooves 26 lying between the coils 28, and the wire ends 32 are connected to connector elements 36 on one side, and the connector leads 34 are connectable via plug connectors 40 on the other side. The retaining elements 38 are mounted at a form-fit in plug connectors 44 formed by insulating end disks 42 of the stator 22.

Abstract: The invention pertains to a control circuit for a collectorless DC motor where at least one power transistor (14, 16) is input-connected to each stator coil (2, 4) of the motor; said transistor is driven by at least one rotor position sensor, especially a Hall generator having commutation circuits to commute the motor current, and where a blocking protection device is provided to interrupt the motor current in an overload or blockage. The blocking protection device (26) has at least one semiconductor circuit (30) carrying the motor current which is switched through or blocked depending on its temperature.

Abstract: The invention relates to a collectorless direct-current external-rotor motor (2), which includes a stator (6) with stator windings (12) fastened to a motor flange (4), an external rotor (14) enclosing the stator (6) on its side facing away from the motor flange (4), as well as an electronic circuit arrangement (18) driving the stator windings (12). This circuit arrangement (18) has a conductor plate (24) provided with electronic components (22) arranged adjacent to the flange-side facing the stator (6), as well as several power semiconductors (28) electrically connected to the conductor plate (24), arranged in heat-conducting contact with the motor flange (4). The power semiconductors (28) are joined indirectly by an annular disk-form cooling body (40) to the motor flange (4) to provide a heat-conducting effect. The cooling body (40) forms a preassembled component with the conductor plate (24) and a carrier element (42) which support the conductor plate (24).

Abstract: Method and apparatus for driving an alternating-current motor. A sinusoidal supply AC voltage is rectified into a pulsating, unsmoothed DC voltage, with sinusoidal half waves and from this DC voltage an alternating-current motor voltage is produced by means of controllable polarity reversal. The pulse width of this alternating-voltage of the motor can be modulated. The polarity reversal takes place in accordance with the supply frequency in such a way that the AC voltage of the motor is essentially composed of the sinusoidal half waves of the pulsating DC voltage. For this purpose, the motor speed can be altered by changing the AC voltage of the motor with a constant timing frequency, lying outside the range of audibility, into pulse-width modulatable voltage pulses.

Abstract: Asymmetrical shaded-pole motor (1) with a stator (2) consisting of a laminated core is formed from a C-shaped yoke, between whose free yoke prongs (7, 8), a yoke stay (4) is inserted, on which a main winding sits. A short-circuited auxiliary winding (9) is provided in the leg connecting the yoke prongs, and in a recess in this leg, there is a laminated squirrel-cage rotor (3) with a small air gap to the stator (2), mounted so it can rotate on a motor shaft (17). The squirrel-cage rotor (3) is designed as a hollow cylinder and directly surrounds coaxially a bearing supporting tube (13) that is connected to the stator (2) and projects into its interior from the open end, such that the motor shaft (17) is guided by bearings (14) in it, and is connected to the rotor (3) on the end opposite the bearing supporting tube (13).

Abstract: A ventilator housing with at least one protective screen for covering a ventilator positioned in a housing, whereby through-hole borings for fastening the protective screen with fastening elements are provided in the walls of the housing. The fastening elements are formed as pin-shaped fastening studs, which can be inserted into the through-hole borings of the housing walls, and which have, on their peripheral surfaces, tongue-like springy counter-hooks which are directed in the direction opposed to the direction of insertion of the stud, being angularly to the longitudinal axis of the stud, so that after insertion of the studs into the borings, at least one counter-hook engages the housing wall under prestressing.

Abstract: A collectorless direct-current motor with a stator mounted on a motor flange and a rotor mounted so that it can rotate on a shaft, in which case power semiconductors for the purpose of commutating the currents of the stator are attached to parts of the motor for the purpose of dissipating the heat and a circuit board with electronic components is provided for the purpose of controlling the commutation, and the power semiconductors are electrically connected to the circuit board, in which case the power semiconductors (39) are attached to the motor flange (2), preferably the outside (29) thereof, in heat conducting contact.

Abstract: A protection circuit for stalling protection in commutatorless direct current motors is driven by Hall generators, in particular Hall IC's. A respective semiconductor circuit element (5, 14) disposed in series with each stator winding (1, 2) is turned on or off in dependence on a control voltage induced in the stator windings (1, 2). The control voltage (U.sub.B) is constituted by the sum of the operating voltage in the unenergized windings (1, 2) and the counter-e.m.f. induced in these windings, whereby, if the sum of these voltages is greater than the operating voltage, the semiconductor circuit element (5, 14) connected to the respective energized winding (1, 2) is turned on, and, if the counter-e.m.f. is zero or falls below a predetermined cut-off value, the respective semiconductor circuit element (5, 14) is turned off.

Abstract: External rotor motor for driving ventilators, the motor having an overhung rotor and a stator connected with a motor flange. The stator has a stator winding and stator laminations, and is equipped with an insulating layer made of plastic and sprayed on the stator laminations. The insulating layer extends over the inner side of an axial stator borehole of the stator laminations and, at least in areas, over the front sides of the stator laminations. A rotatable rotor shaft extends through the axial stator borehole, and the rotor shaft is connected with the rotor in a fixed manner on the end opposite the motor flange. At least one metal heat conducting element is provided which, on one end, directly contacts or engages the stator laminations for conducting heat from the limitations and, on the other end, contacts the motor flange for the removal of the heat to the motor flange.

Abstract: Arrangement for joining the cable ends (7) of a stator winding of electric motors, in particular external rotor motors (5), with a connecting lead, using electrical connecting elements (6) and an insulating disc (1) arranged at one end of the stator, which disc has an opening passing from the front insulating shaft (9) of the stator plates (13) of the electric motor and serves to cover as well as insulate the winding head (4) of the stator winding, wherein the connecting elements (6) are formed as connectors (15) and in each case a connector part is held in a frictional or positive locking manner on the insulating disc (1).

Abstract: An external rotor motor, especially for driving fans, including a stationary inside stator, an outside rotor, and a stator-lamination pack of the inside stator having a central bore into which there is installed, with the aid of a clamping seating, a stator bushing which is connected mechanically on one side with the motor flange carrying the external rotor motor. Inside the stator bushing, there is a turnable shaft which is fixedly secured, on the side lying opposite the motor flange, within a rotor bushing of the turnable outside rotor. The motor flange includes on the inside, a hollow cylindrical added piece with an inward-directed annular crosspiece, which abuts against the stator-lamination pack. The stator bushing, installed with the aid of a clamping seating in the central bore of the stator-lamination pack, has an outward-directed annular crosspiece which is seated against the inward-directed annular crosspiece of the cylindrical added piece of the motor flange.

Abstract: Electric motor with a system for speed monitoring, especially for ventilators, fans, blowers and compressors, where the speed is monitored with the help of a speed-proportional signal, consisting of a stator and a rotor which can rotate in the stator, where the system for speed monitoring consists of a permanent magnet (16) which is mounted in the front end (14) of the rotor (2) which faces the stator (3) and a detector (12) which can be triggered by the magnetic field of the permanent magnet and is located on a circle with its midpoint in the axis (4) of rotation of the rotor (2) and with a radius corresponding to the radius of the circular path of the permanent magnet (16).

Abstract: A commutatorless D.C. motor with cylindrical air gap, consisting of a stator with three stator winding strands displaced by 120.degree. electrical and with a permanent-magnetic external rotor with at least p=1 pairs of poles and with N=2p.times.3 winding slots in the stator as well as with at least two rotation position detectors composed of Hall generators, which switch on and off the individual winding strands depending on the rotation position of the rotor, in which connection the rotor (7) exhibits p=2 or p=4 pairs of poles, and the stator windings are full pitch, also each winding strand (3,4,5) is subdivided into w=2p winding sections, whose central axes exhibit a separation of 180.degree. electrical, viewed in the direction of rotation, and the direction of winding of the winding sections is such that at the periphery of the stator (1) alternating North and South poles, viewed in the direction of rotation, are produced by the winding sections.

Abstract: A drive circuit for brushless direct-current motors having a cylinder-like air gap between a permanent magnetic inner or outer rotor and a stator, the stator windings being connected to a supply direct-current source in series with a respective feed transistor. The current flux depends on position signals from a semiconductor control element determining the rotor position, in particular a Hall IC, and on the switching state of a semiconductor switch responding to blocking of the rotor and serving as blocking protection for the stator windings. In order to avoid a thermal overload of the stator windings and of the semiconductor elements contained in the circuit, the semiconductor switch provided as the blocking protection is a transistor.

Abstract: An axial-flow fan includes an impeller and a supporting member, a hollow elongated casing having a circumferential wall, an inlet and an outlet axially spaced from the inlet and defining with the circumferential wall the interior of the casing accommodating the impeller and the supporting member. The circumferential wall comprises a first conical annular portion adjacent to the inlet and diverging in the direction from the outlet to the inlet, a second conical annular portion adjacent to the outlet and diverging in the direction from the inlet to the outlet.