Abstract: In a method of producing an add-on part of a drive, one circuit board of multiple planar circuit boards, which have electrical conductor tracks with electrical connections, is provided with a centrally arranged opening for passage of a shaft. The circuit boards are populated with electrical and/or electronic components, and the populated electrical and/or electronic components and wiring are electrically tested. Segments made of a material with high thermal conductivity are arranged on at least two of the multiple circuit boards such that a bending process in a region of the electrical connections between the at least two circuit boards causes the segments to form an approximately peripherally closed cover. Lids are arranged on open sides of the cover to realize a closed housing arrangement.

Abstract: A method for early detection of developing damage in a bearing caused by flow of a bearing current includes evaluating a long-term measurement of a measured variable representative of a bearing current amplitude of a bearing current during a bearing operation, representing—based on the evaluation—measurement results in form of a histogram which displays a number of bearing currents per time interval in each interval of the bearing current amplitude, and evaluating the histogram representation of the measurement results through pattern comparison. A device for carrying out the method is also disclosed.

Abstract: A method and device for assessing damage to a rolling bearing caused by bearing currents, in particular high-frequency bearing currents, in an electric machine which is electrically connected to an inverter, in particular to an inverter having a DC voltage link circuit, is described. The rolling bearing has a lubrication gap between an inner bearing ring and a rolling body and between an outer bearing ring and the rolling body. The method includes detecting the energy of an electric discharge event in the lubrication gaps, searching for a coincident event having a frequency above one GHz indicative of a damaging bearing current event, detecting a frequency of occurrence of discharge events, and evaluating the discharge events by correlating the frequency of occurrence and the energy of the discharge events.

Abstract: Electric arc discharges between bearing rings in a roller bearing are analyzed by setting a defined operating state based on rotational speed of the roller bearing, temperature of the roller bearing, an imbalance of the roller bearing causing vibrations, lubricants, axial/radial/tilt loads, tilting of the bearing rings relative to each other, pulse shape and pulse repetition rate of an applied electrical voltage, bearing play, and pre-existing damage to the roller bearing. A pulse-shaped electrical voltage between inner and outer bearing ring generates electric arc discharges, wherein for each electric arc discharge a characteristic value representative of energy, power, voltage and/or current and duration of the electric arc discharge is determined. Only those electric arc discharges are evaluated that have a qualifying value determined in accordance with at least one of the characteristic values greater than a predefined limit value.

Abstract: In a method for determining and/or monitoring the state of a roller bearing wherein during the operation of the roller bearing a sensor signal in the form of a sound emission signal is detected in a frequency band in the ultrasonic range, according to an embodiment of the invention shock pulses in the sensor signal are determined. As a result, electrical bearing currents in the roller bearing can be detected and damage to the bearing can therefore be avoided early.

Abstract: A method for early detection of developing damage in a bearing caused by flow of a bearing current includes evaluating a long-term measurement of a measured variable representative of a bearing current amplitude of a bearing current during a bearing operation, representing—based on the evaluation—measurement results in form of a histogram which displays a number of bearing currents per time interval in each interval of the bearing current amplitude, and evaluating the histogram representation of the measurement results through pattern comparison. A device for carrying out the method is also disclosed.

Abstract: In a system for ascertaining a bearing state and in a method for ascertaining a bearing state of a bearing of an electric machine, measurement value (21) is ascertained by means of a sensor unit (20). The measurement value is transmitted to a simulation unit (22), wherein a result value (23) is ascertained by means of the simulation unit (22), wherein the result value is in particular a bearing-current value or a value that is dependent on the bearing current. The result value (23) can be transmitted to a further unit (24).

Abstract: The grounding quality of an electric machine should be better monitored. Therefore, an electric machine is proposed, comprising a stator (1), a rotor (2), a shaft (3), to which the rotor (2) is fastened, and a grounding device (5) for grounding the shaft. The electric machine also has a measuring device (6) for measuring a ground current of the grounding device (5) and for providing a corresponding measured value. The electric machine also has a monitoring device (7) for monitoring the grounding function of the grounding device (5) on the basis of the measured value. In this way, the state of a grounding brush in regard to soiling and wear, for example, can be continuously monitored.

Abstract: Electric arc discharges between bearing rings in a roller bearing are analyzed by setting a defined operating state based on rotational speed of the roller bearing, temperature of the roller bearing, an imbalance of the roller bearing causing vibrations, lubricants, axial/radial/tilt loads, tilting of the bearing rings relative to each other, pulse shape and pulse repetition rate of an applied electrical voltage, bearing play, and pre-existing damage to the roller bearing. A pulse-shaped electrical voltage between inner and outer bearing ring generates electric arc discharges, wherein for each electric arc discharge a characteristic value representative of energy, power, voltage and/or current and duration of the electric arc discharge is determined. Only those electric arc discharges are evaluated that have a qualifying value determined in accordance with at least one of the characteristic values greater than a predefined limit value.

Abstract: A method and device for assessing damage to a rolling bearing caused by bearing currents, in particular high-frequency bearing currents, in an electric machine which is electrically connected to an inverter, in particular to an inverter having a DC voltage link circuit, is described. The rolling bearing has a lubrication gap between an inner bearing ring and a rolling body and between an outer bearing ring and the rolling body. The method includes detecting the energy of an electric discharge event in the lubrication gaps, searching for a coincident event having a frequency above one GHz indicative of a damaging bearing current event, detecting a frequency of occurrence of discharge events, and evaluating the discharge events by correlating the frequency of occurrence and the energy of the discharge events.

Abstract: Converter and method for controlling a converter with power semiconductor switches, having a filter (1) which is connected to the power semiconductor switches and having a drive circuit (4) which is connected to the power semiconductor switches for the purpose of modulation, wherein, as a result of the modulation, a fundamental at a fundamental frequency (fGS) is generated in a passband (P) of the filter (1), modulation products are generated in a first frequency band (FB1), in a second frequency band (FB2) and in an intermediate frequency band (ZFB) which is formed between the first frequency band (FB1) and the second frequency band (FB2), the modulation products in the intermediate frequency band (ZFB) are reduced in comparison with the modulation products in the first frequency band (FB1) and the modulation products in the second frequency band (FB2); and the intermediate frequency band (ZFB) is generated, in a resonant range (R) of a resonant frequency (fres) of the filter (1), between the passband (P) an

Abstract: Converter and method for controlling a converter with power semiconductor switches, having a filter (1) which is connected to the power semiconductor switches and having a drive circuit (4) which is connected to the power semiconductor switches for the purpose of modulation, wherein, as a result of the modulation, a fundamental at a fundamental frequency (fGS) is generated in a passband (P) of the filter (1), modulation products are generated in a first frequency band (FB1), in a second frequency band (FB2) and in an intermediate frequency band (ZFB) which is formed between the first frequency band (FB1) and the second frequency band (FB2), the modulation products in the intermediate frequency band (ZFB) are reduced in comparison with the modulation products in the first frequency band (FB1) and the modulation products in the second frequency band (FB2),; and the intermediate frequency band (ZFB) is generated, in a resonant range (R) of a resonant frequency (fres) of the filter (1), between the passband (P) a