Abstract: Determining the rotor angle of a synchronous machine. In one aspect, the invention provides a method that includes generating a multiplicity of pulse-width-modulated drive signals for the phases of an inverter feeding the synchronous machine depending on a voltage to be fed into the synchronous machine, and applying a first phase shift to one or more of the multiplicity of pulse-width-modulated drive signals, so that the duration of the switching states of the inverter is extended in order to generate a first switching pattern for the phases of the inverter. The method also includes applying a second phase shift to one or more of the multiplicity of pulse-width-modulated drive signals for generating a second switching pattern, selecting one or more of the first and second switching patterns, determining one or more of neutral point potentials at the neutral point of the synchronous machine, and calculating the rotor angle of the synchronous machine.

Abstract: A method for determining the rotor angle of a synchronous machine. In one implementation, the method includes generating a multiplicity of pulse-width-modulated drive signals for the phases of an inverter feeding the synchronous machine depending on a voltage to be fed into the synchronous machine, changing the pulse width modulation frequency of at least one drive signal of the multiplicity of pulse-width-modulated drive signals, with the result that the duration of the switching states of the inverter in which an active voltage phasor is output is extended in order to generate a switching pattern for the phases of the inverter, driving the inverter with the generated switching pattern, determining one or more of neutral point potentials at the neutral point of the synchronous machine during driving of the inverter with the switching pattern, and calculating the rotor angle of the synchronous machine depending on the determined neutral point potentials.

Abstract: Determining the rotor angle of a synchronous machine. In one aspect, the invention provides a method that includes generating a multiplicity of pulse-width-modulated drive signals for the phases of an inverter feeding the synchronous machine depending on a voltage to be fed into the synchronous machine, and applying a first phase shift to one or more of the multiplicity of pulse-width-modulated drive signals, so that the duration of the switching states of the inverter is extended in order to generate a first switching pattern for the phases of the inverter. The method also includes applying a second phase shift to one or more of the multiplicity of pulse-width-modulated drive signals for generating a second switching pattern, selecting one or more of the first and second switching patterns, determining one or more of neutral point potentials at the neutral point of the synchronous machine, and calculating the rotor angle of the synchronous machine.

Abstract: A method for determining the rotor angle of a synchronous machine. In one implementation, the method includes generating a multiplicity of pulse-width-modulated drive signals for the phases of an inverter feeding the synchronous machine depending on a voltage to be fed into the synchronous machine, changing the pulse width modulation frequency of at least one drive signal of the multiplicity of pulse-width-modulated drive signals, with the result that the duration of the switching states of the inverter in which an active voltage phasor is output is extended in order to generate a switching pattern for the phases of the inverter, driving the inverter with the generated switching pattern, determining one or more of neutral point potentials at the neutral point of the synchronous machine during driving of the inverter with the switching pattern, and calculating the rotor angle of the synchronous machine depending on the determined neutral point potentials.

Abstract: The invention relates to an electric motor (10) and to a method for producing said electric motor, especially for adjusting mobile parts in a motor vehicle. Said electric motor comprises a collector (36), arranged on an armature (38) and electrically contacted via hammer brushes (12). The armature (38) is surrounded by a lower housing part (32) and an upper housing part (34) which can be assembled in a radial direction (50) in relation to the armature (38). The hammer brushes (12) comprise one fastening element (26) each which engages directly in a seat (30) of the lower or upper housing part (32, 34).

Abstract: The invention relates to an electromotor (1) having a conducting rotor shaft (3), a contacting element (10) for electrically contacting the rotor shaft (3), and a connection device (14) for connecting the rotor shaft to a virtual or fixed potential.

Abstract: The invention relates to an electric motor (10) and to a method for producing said electric motor, especially for adjusting mobile parts in a motor vehicle. Said electric motor comprises a collector (36), arranged on an armature (38) and electrically contacted via hammer brushes (12). The armature (38) is surrounded by a lower housing part (32) and an upper housing part (34) which can be assembled in a radial direction (50) in relation to the armature (38). The hammer brushes (12) comprise one fastening element (26) each which engages directly in a seat (30) of the lower or upper housing part (32, 34).

Abstract: The invention relates to a plastic gear, particularly a worm gear, with teeth disposed side by side in circumferential direction. Provision is made according to the invention for the surface of at least one of the teeth to be structured in such a way as to constitute a grease depot. The invention additionally relates to a drive as well as to a method for introducing a structure, which constitutes a grease depot, into the surface of at least one tooth of a plastic gear.

Abstract: In a method of monitoring the condition of soiling and/or calcification of heat exchangers in heating installations, subsequent operational data of temperature and pump speed are collected in turns during the operation and compared with the initial operational data of temperature and pump speed collected in an initial condition, for instance when an installation is put into service initially. When an admissible deviation of the subsequent operational data from the initial operational data is exceeded, which is as a rule to be attributed to the soiling and/or calcification of the heat exchanger, a corresponding malfunction signal is emitted or the heating installation is switched off. In accordance with the method, a conventional heating installation is provided with a monitoring device, by means of which the soiling and/or calcification of the heat exchanger is automatically checked in turns.