Abstract: A magnetic bearing for generating magnetic forces. A configuration of electromagnetic poles and of permanent magnetic poles which, to the greatest possible extent, is planar enables the generation of a magnetic flux in the air gaps toward the rotor, also in the de-energized state. If this flux is modulated using a control flux, magnetic forces can be exerted upon the rotor for the purpose of providing magnetic support. This configuration makes it possible to provide magnetic bearings of a simple mechanical design.

Abstract: Magnetic field gradients are used e.g., for potential-free current measurement without voluminous ferrite cores to minimize the influence of homogenous external interference fields on the measurement. So far, they have been provided mainly through U-shaped primary current conductors. The aim is to make it unnecessary to guide high currents through U-shaped current conductors, and to provide a device and a method for creating one or more magnetic field gradients through a straight conductor. To this end, a primary current conductor which is straight at the point where the magnetic field is measured has a recess or groove or slot for creating a magnetic field gradient. Inside or in the area surrounding this recess, the field lines take a course that enables one or more gradiometers to be positioned so that the influences of especially homogenous interference fields on the measurements are successfully minimized using simple mathematical methods such as subtraction.

Abstract: The invention relates to a method for evaluating signals while eliminating an interference signal on magnetoresistive sensor elements which is preferably proportional to the zero offset. The sensor elements can form a sensor element array such as a sensor bridge. According to the invention, the direction of magnetization of the sensor elements is modulated or shifted by applying a magnetic pulse field of a modulated or variable direction, and the output signals of the sensor elements or of the sensor element array are fed to a differential amplifier. Due to the modulation or shift of the operating voltage of the sensor bridge, the modulation or shift resulting at the same time as the magnetization of the sensor elements, a signal often arises which includes a direct component that is proportional to the magnetic field to be measured, and has an alternating component that is proportional to the offset voltage of the sensor element array. The latter is minimized by a feedback or is adjusted to zero.

Abstract: A radial, active magnetic bearing apparatus comprising at least three electromagnets which are distributedly arranged is excited by a three-phase rotary current controller.

Abstract: A method and device for measuring electric currents in n conductors (n≧2), the measurement of the currents being carried out with (n−1) magnetoresistive sensors. Reliable excess current and/or fault current protection is obtained.

Abstract: A magnetic bearing apparatus for the journalling of a body (3), in particular of a rotor (3), comprises a stator (2) with a control winding (22) having at least three loops (22a, 22b, 22c) for the production of a magnetic control field by means of which the position of the body (3) relative to the stator (2) can be regulated, with each loop (22a, 22b, 22c) belonging to a different electrical phase, and a control device (4) which in a first operating mode supplies each loop (22a, 22b, 22c) with in each case a phase current (Ia, Ib, Ic) or in each case a phase voltage (Ua, Ub, Uc) as a control parameter. Means are provided in order to regulate the control parameter for each loop (22a, 22b, 22c) independently of the control parameter for the other loops (22a, 22b, 22c) as well as a monitoring unit (5) which can switch the bearing apparatus into a second operating mode in which a reduced number of phases, which is at least two, produces the magnetic control field.

Abstract: A permanent magnetically excited electrical rotary drive for a blood pump is proposed, comprising a permanent magnetic rotor and a stator, said stator comprising a drive winding having at least two loops for the production of a magnetic drive field which produces a torque on the rotor, with each loop belonging to a different electrical phase, furthermore comprising a setting device which supplies each loop in each case with a phase current or in each case with a phase voltage as a setting parameter, with the setting device comprising a separate power amplifier for each loop so that the setting parameter for each loop can be regulated independently of the setting parameter for the other loops.

Abstract: In a method for the determination of the radial position of a permanent magnetic rotor (1) in an electromagnetic rotary drive which is designed as a bearing-free motor with a stator (2) and the magnetically journalled rotor (1) the magnetic flux which is produced by the rotor (1) is determined by means of sensors (LS1, LS2, LS3) in the space between the rotor (1) and the stator (2) at least at two different measurement locations. The radial position of the rotor (1) is established with the help of the magnetic flux which is determined at the measurement locations and with the help of the magnetic flux which results at the measurement locations when the rotor (1) is arranged so as to be centered. Furthermore, a sensor arrangement for the determination of the radial position of the permanent magnetic rotor is proposed.

Abstract: A method for the excitation of the radial force and torque winding systems of electrical drives with integrated magnetic bearings. The drives comprise an electrical machine with torque and radial force windings which are introduced in the stator or rotor, a position and angle sensor system and analog or digital electronic circuitry for the control, regulation, monitoring and feeding of the machine. A model is used for setting the rotor position (36,37) and the rotational angle of the rotor (&phgr;) which describes the relationship between the forces acting radially and tangentially at the rotor or at the stator respectively and the loop currents, and indeed in such a manner that it takes into account the deviations from the sinusoidal form of the force components, which depend on the rotational angle of the rotor (&phgr;).

Abstract: A centrifugal pump for delivering a fluid has a pump housing that comprises a first and a second inlet as well as a first and a second outlet for the fluid, a magnetically mounted impeller located inside pump housing, said impeller being rotatable around a rotation axis, and comprising a magnetically active rotor in the shape of a disk or ring, as well as two sets of vanes, with one set of vanes being provided on each of the two axial boundary surfaces of rotor. The two outlets are offset with respect to one another in the axial direction.

Abstract: A sensor arrangement in an electromagnetic rotary drive which is designed as a bearing-free motor with a magnetically journalled, permanent magnetic rotor (1) and a stator (2), said sensor arrangement serving for the determination of the direction of the rotor magnetisation and/or of the axial position of the rotor (1), comprises at least two sensors (S1, S2, S3) for the determination of a magnetic flux. The two sensors (S1, S2, S3) are arranged in such a manner with respect to the rotor (1) that partial fluxes of that magnetic field which the stray field of the permanent magnetic rotor (1) produces can be determined with them. Furthermore, a method for the determination of the direction of the rotor magnetisation is proposed.

Abstract: A magnetically journalled rotational arrangement comprises a bearing stator and a rotor, with the bearing stator being magnetically coupled to the rotor and producing a magnetic journalling of the rotor. The bearing stator is rotatably journalled. Furthermore, a rotary drive which is associated with the bearing stator is provided, with a rotation of the bearing stator producing a rotation of the rotor via the magnetic coupling of the stator to the rotor.

Abstract: A centrifugal pump for delivering a fluid, especially for delivering blood, has a pump housing (2) that has an inlet (3) and an outlet (4) for the fluid, as well as an impeller (5) located inside pump housing (2), said impeller having a plurality of vanes (51) and being rotatable around a rotational axis (A), as well as means for driving impeller (5). Outlet (4) is located offset in the axial direction with respect to impeller (5).

Abstract: The invention relates to an apparatus for the contact-free journalling of a rotor by rotary field machine stators. The rotary field machine stators are magnetically coupled, on the one hand, via the rotor of ferromagnetic material and, on the other hand, via a flux conduction ring of a ferromagnetic material and/or a housing of a ferromagnetic material. The radial magnetic bearing forces in the rotary field machine stators are produced in that means are present in the arrangement which produce magnetic unipolar fluxes flowing through the rotary field machine stators. Two-pole control fluxes are superimposed on the unipolar fluxes in the rotary field machine stators, and the control fluxes are controlled by the currents in two-pole rotary field windings. The position of the rotor is measured by position sensors. A control apparatus calculates the required phase currents as a result of the position signals and feeds the rotary field windings in such a manner that the rotor is held in suspension.

Abstract: The rotary machine comprises a driven rotor and an electric motor having a stator and a driving rotor. The stator is also executed as an electromagnetic bearing for the driving rotor, and the driving rotor of the electric motor together with the driven rotor of the rotary machine forms a rotor unit, i.e. the two rotors form an integral rotor. The rotary machine can for example be a rotary pump, a centrifugal pump, a centrifuge or a stirring apparatus. The rotor can be constructed so as to be easily removable from the stator.

Abstract: The rotary pump (3) according to the invention comprises a housing (9) and a rotor (2) with blades (1b) located inside the housing (9), with the rotor (2) comprising a passive, magnetically effective rotor part (1) and the housing (9) being surrounded by a stator (7) that has electrical windings (8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h) and teeth (7a, 7b, 7c, 7d, 7e, 7f, 7g, and 7h), with the stator (7) and the rotor part (1) forming a bearingless motor, and with the rotor part (1) being actively controllable and drivable by means of the electrical windings (8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h) relative to three degrees of freedom, and with the rotor part (1) and the teeth (7a, 7b, 7c, 7d, 7e, 7f, 7g, and 7h) of the stator (7) being designed to be geometrically adapted to one another and arranged with respect to one another in such fashion that the rotor part (1) can be held by passively acting reluctance forces in the stator (7) with respect to three additional non-actively-controllable degrees of freedom, in order to loc

Abstract: The gap tube motor comprises a rotor, a stator and a gap tube which is arranged between the rotor and the stator, with at least two bearing apparatuses being arranged with a spacing in the axial direction (A) with respect to the rotor, and with at least one of the bearing apparatuses being designed as a bearing and drive apparatus and comprising both an electrical motor drive apparatus and a magnetic bearing apparatus in order to both drive the rotor and to journal the rotor in the radial direction without contact using this bearing and drive apparatus.

Abstract: Measuring devices for determining magnetic fields to be used in particular for the potential-free measurement of the strength of an electric current which generates such a magnetic field. To obviate the need for an intermediate element specially connected into the relevant current conductor and to allow the measurement device instead to be accommodated in a clamp device which needs only to be slipped over the current conductor, the proposed embodiment has two measuring bridges which are fixed on either side of the current conductor, the staggering of the two bridges is assessed from the current magnetic field via a control circuit.

Abstract: The arrangement or apparatus for operating a magnetically suspended, electromotoric drive apparatus in the event of a mains disturbance comprises a drive converter feeding the drive apparatus, a driver feeding a magnetic bearing and a voltage converter, which are connected to a common intermediate circuit. The voltage converter feeds a stopping control apparatus and the drive converter can be switched to a regeneratively acting mode of operation by the stopping control apparatus in the event of a mains disturbance in order to provide at least the driver feeding the magnetic bearing and the stopping control apparatus with electrical energy via the intermediate circuit.

Abstract: A method for the compensation of periodic shaking forces in an AC-machine having a special winding for the combined generation of a torque and a transverse force. The compensation takes place by a pre-control that acts on the desired force (at the input of the control method) or on the control current, and which is dependent on the flux angle, on the mechanical rotor angle, on the angular velocity of the flux, and on the mechanical angular velocity of the rotor. Additionally, linear and non-linear errors in the control of the transverse force vector such as arise from slot harmonics and winding harmonics and from the material saturation are compensated by a rotation stretching of the control current vector dependent on the flex vector.