Abstract: An electronically commutated motor (ECM) often employs a Hall sensor for reliable operation. Even when a Hall sensor is omitted from a motor having a plurality of stator winding phases (24, 26) and a permanent-magnet rotor (22), one can reliably detect direction of rotation of the rotor by the steps of: (a) differentiating a voltage profile obtained by sampling either (1) induced voltage in a presently currentless phase winding or (2) voltage drop at a transistor, through which current is flowing to a presently energized phase winding, and (b) using such a differentiated signal (du—24?/dt, du—26?/dt) to control current flow in an associated phase winding. In this manner, one obtains reliable commutation, even if the motor is spatially separated from its commutation electronics.

Abstract: An electric motor has a DC link circuit (30, 32), a permanent-magnet rotor (104), and a control circuit having a full bridge (114). A program-controlled calculation arrangement (80) is configured to supply the semiconductor switches of a first bridge half with a PWM signal (136, 136?) and to supply the semiconductor switches (118, 122) of the second bridge half with a commutation signal (O1, O2; 150, 150?). An energy storage device (170) is provided which, during normal operation of the motor (102), is chargeable from the DC link circuit (30, 32) and serves, upon cessation of the signals from the calculation arrangement (80), to make the semiconductor switches (118, 122) of the other bridge half conductive, and thereby to short-circuit the stator winding arrangement (106) through those semiconductor switches (118, 122) in order to decelerate the permanent-magnet rotor (104) and to thereby minimize risk of human injury.

Abstract: An electric motor has a rotor (52) rotatable around a rotation axis (56) and has a stator (60) arranged around said rotor (52), which stator is equipped with poles (11? to 16?). Each pole has an individual winding (11 to 16), and the latter together form a winding arrangement (30) that serves to generate a rotating field. Arranged approximately concentrically with the rotation axis (56) is an arrangement having electrical connection elements (U, V, W, U?, V?, W?). The latter are equipped with mounting elements (34, V1, W1, U?1, V?1, 32, 36) to each of which an associated end of an individual winding is mechanically and electrically connected. A connection arrangement (40) has a plurality of conductors (42, 44, 46) each of which is connected, by means of a welded connection (155), to the connection elements of the stator in order to electrically interconnect them in a predetermined fashion.

Abstract: An electronically commutated one-phase motor (20) has a stator having at least one winding strand (30, 32) and a permanent-magnet rotor (22). The rotor, as it rotates, induces a voltage (uind) in the at least one winding strand (30, 32). The motor has an electronic calculation device (26), preferably a microcontroller ?C, which is configured to execute, during operation, the steps of a) sensing the value of the instantaneous operating voltage (Ub); (b) using the operating voltage value (Ub) and optionally further parameters, adjusting a time duration (TON) of a switch-on current pulse (i30) for the motor, in order to apply a consistent amount of electrical energy to the windings during start-up attempts, thereby maximizing the probability of successful start-up, regardless of possible fluctuations in motor operating voltage and related operating parameters. The switch-on current pulse duration (TON) can be adjusted longer or shorter, as a function of operating experience.

Abstract: An electronically commutated asynchronous motor (12) features a stator (202), a short-circuit rotor (204), a controller (FOR 20) for field-oriented regulation of the motor (12), a sensor magnet (274) in thermally conductive connection with the short-circuit rotor (204), a rotor position sensor (14A; 18; 18?) arranged at a predetermined distance (d) from the sensor magnet (274) to generate an output signal (HALL, U, U1, U2) that is dependent upon the spatial orientation of the sensor magnet (274), and a temperature evaluation apparatus (CALC_T 44) configured to ascertain, during operation, from the sensor output signal (HALL, U, U1, U2), a temperature value (T) that characterizes a temperature (T_SM, T_S) in the motor (12).

Abstract: An electric motor has a stator (224) having a bearing tube (238) made of a magnetically transparent material; it also has a rotor (222) having a rotor shaft (234) that is at least partially journaled in the bearing tube (238), and has a ring magnet (250) that is fixedly arranged on the rotor shaft (234) inside the bearing tube (238). Two magnetic-field-dependent analog sensors (248?, 248?) are arranged on a circuit board (246) outside the bearing tube (238), at an angular distance (PHI) from one another, in order to generate rotor position signals as a function of the rotational position of the ring magnet (250). A corresponding device (150) that serves to control the motor is provided, in order to process these rotor position signals into a signal that indicates the absolute rotational position of the rotor (222).

Abstract: A method of making a fan having one or more dust-resistant surfaces comprises the steps of: providing (S50) an open mold for injection-molding purposes, having a cavity (43) corresponding to the desired configuration of fan components to be formed; wetting (S52) the surface of the cavity (43) with a mixture (24) of nanoparticles (19) and a solvent carrier; evaporating (S54) said solvent carrier, thereby depositing said nanoparticles on the wall of the cavity (43); closing (S56) the injection mold (10, 12); injecting (S58) thermoplastic (42) into the cavity (43); permitting the thermoplastic to harden, thereby binding the nanoparticles into the surface of the thus-created component(s), and removing (S60) the completed component(s) from the mold, for subsequent assembly as part of a fan.

Abstract: An electrically driven fan arrangement, suitable for energy-conserving installations, includes a fan, an electric motor (110) serving to drive the fan, and associated control apparatus, namely: a sensing apparatus (140) for sensing a volumetric air flow rate (125) generated by the fan (120) and for generating a measured volumetric air flow value (Vmess), and a volumetric flow rate control arrangement (160) for automatically controlling the volumetric air flow rate (125) generated by the fan (120) to a predetermined target volumetric air flow value (V_s). The volumetric flow rate control arrangement (160) is configured to generate a target rotation speed value (N_s) for the electric motor (110). A rotation speed controller (170), which automatically controls the rotation speed of the electric motor (110) to the target rotation speed rate (N_s) generated by the volumetric flow rate control arrangement (160), is also provided.

Abstract: A two-stranded electronically commutated DC motor has a permanent-magnet rotor (36), power supply terminals (28, 30) for connecting the motor to a current source (22) and a stator (102) having a winding arrangement which includes first and second winding strands (52, 54). The latter are controlled by respective first and second semiconductor switches (70, 80). The motor also has a third controllable semiconductor switch (50), arranged in a supply lead from one of the terminals (28, 30) to the winding strands (52, 54), which third switch is alternately switched on and off by applying to it a PWM (Pulse Width Modulated) signal 24. During switch-off intervals, magnetic flux energy stored in the motor causes a decaying loop current (i2) to run through the windings, continuing to drive the rotor. This facilitates conformal mapping of temperature information in the PWM signal onto a target motor rotation speed.

Abstract: An electronically commutated electric motor (110) has a permanent-magnet rotor (28), a stator having a stator winding arrangement (40), a motor control module (20) implemented as an IC and having a control logic unit (27), and an external power stage (50), separate from the IC, for influencing the current flow in the stator winding arrangement (40). The motor control module (20) has an internal power stage (29) having at least one open collector output (21, 23). The control logic unit (27) is configured to process a rotor position signal (24?, 24?) and to generate therefrom control signals (27?) for the internal power stage (29), which control signals (27?) serve to apply control to the internal power stage (29). Using an external power stage (50) reduces vulnerability to motor overheating and provides design flexibility.

Abstract: For many applications, it is desirable to use fans which weigh less than 30 grams and are driven by electric motors not more than a few centimeters in size. Mass-producing products this small, which nevertheless must be extremely reliable, poses unique manufacturing challenges, which are best overcome by an improved structure which is susceptible to automation. Preferably, the fan motor is electronically commutated and has an internal stator (50) and an external rotor (22) supported on a central rotor shaft (34). The shaft is journaled within a bearing tube (70) supporting first and second rotor bearings (72, 76). By injection-molding the bearing tube (70) with first and second axial extensions (90?, 90?), the extensions can hold the bearings in place and insure uniform manufacturing quality and a desirably long service life. One of the extensions can also be shaped to abut against a circuit board (46) which supports components which control commutation.

Abstract: A fan has a sensor (86; 186) for sensing at least one value of the air that flows through the fan (20; 120). The fan has a fan housing (22, 24; 122, 124); an electronically commutated external-rotor motor, arranged in that housing, having an internal stator (30; 130) and an external rotor (46; 146); a fan wheel (56; 156) coupled to the external rotor (46; 146); an air inlet opening (58; 90; 158) for the inflow of air that is to be moved by the fan wheel (56; 156); a circuit board (68; 185) having a portion (66; 188) that extends adjacent the air passage opening (58; 158); and conductors (82, 84; 182?, 182?) arranged on that portion (66; 188), to which conductors the sensor (86; 186) is connected, preferably by a Surface Mounted Device (SMD) method. Premounting the sensor on the circuit board facilitates automated manufacture and reduces cost.

Abstract: A fan (100) has an electronically commutated drive motor (ECM 52) with a stator (50) connected to a bearing tube (54) and a rotor (22) on a shaft (34). The shaft (34) is journaled in the tube (54) using passive radial magnetic bearings (16, 18) to minimize friction and wear, is axially displaceable with respect to the tube (54), and is drivingly connected to a rotor magnet (44) forming a first magnetic yoke (46). A second magnetic yoke (27) is connected to the shaft (34), and has an inner surface (59) defining a substantially cylindrical air gap (57) through which, during operation, a radial magnetic flux (55?) extends. A plunger coil (64) extends into the air gap (57) and is mechanically connected to the tube (54) so that, upon axial displacement of the plunger coil (64), the position of the shaft (34) with respect to the tube (54) changes.

Abstract: An electronically commutated motor (ECM 21) has reduced vulnerability to Electro-Static Discharge (ESD). The motor has an internal stator (50) and an external rotor (22) equipped with a permanent magnet (28), which rotor is separated by an air gap from the internal stator (50). The rotor has a shaft (34) on which a magnetic yoke element (24) is mounted. A leakage flux region on an end face (27) of the magnet (28) actuates a Hall sensor (48) located adjacent a first aperture (48?) in a circuit board (46) supporting electronic control components. In order to prevent static discharges from passing through the first aperture (48?) and endangering the electronic components, the circuit board (46) is formed with a second aperture (43) on whose edge is provided at least one electrical conductor (95?, 95?), connected to ground (112), to which any charge that builds up during operation can harmlessly discharge.

Abstract: An equipment fan has a housing (22) that externally defines an air passage opening (41) provided in the fan (20). The fan has a motor (21) for rotatably driving blades (40) about a rotation axis (23), as well as a carrier element (51), provided between the motor (21) and the housing (22), which extends transversely to the passage (41) and is configured as a trough (53) that serves to receive an electrical lead (52) and guides the lead along a predetermined path from the motor (21) to a location (64) on the housing (22). The fan also has a deflection device (50) which, by deflecting the lead (52) at a first deflection location (55) and at a second deflection location (84) and in at least two planes extending at a predetermined angle with respect to one another, effects strain relief for the lead (52) that proceeds to the motor (21).

Abstract: An arrangement for pumping fluids has an electronically commutated external-rotor motor. The latter has a stator arranged on a stator carrier and a rotor joined to a first permanent magnet, which rotor is rotatably journaled, in a bearing tube, with respect to the stator. This bearing tube is arranged, at least partly, radially inside the stator carrier. The first permanent magnet is arranged in an annular interstice between the stator carrier and the bearing tube. A fluid pump has a pump wheel arranged rotatably inside a pump housing, which wheel is joined to a second permanent magnet, a liquid-tight but magnetically transparent partition being provided between the first permanent magnet and the second permanent magnet. This keeps fluid away from the motor wiring. The first permanent magnet forms, by coaction with the second permanent magnet, a magnetic coupling to the fluid pump, which magnetic coupling automatically produces a rotation of the pump wheel as a result of rotation of the motor rotor.