Siemens Aktiengesellschaft

Carsten Probol

Jörg Hassel

Hans Tischmacher

Sven Gattermann

Ralf Kowalewski

Arno Steckenborn

Marc Hiller

Rainer Sommer

Gerd Michaelis

Oliver Theile

Werner Fischer

Michael Brauer

Christian Dietrich

Thomas Fruh

Peter Klein

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&#x2014;based on the evaluation&#x2014;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.

Method and device for the early detection of the development of damage in a bearing

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.

Method and device for assessing the damage to rolling bearings, in particular in inverter-fed electric machines

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.

Electric arc discharge evaluation method, and associated test stand

A measuring method and a device that permit a better evaluation of bearing currents are disclosed. The method uses non-contact measurement of a bearing voltage. A non-contact voltage measurement is performed by means of a series circuit of capacitors. The bearing voltage can be detected especially well in this manner even in the high frequency range.

Device and method for measuring currents in a bearing

An electric machine has a base body in which a stator of the electric machine is arranged. The electric machine has a rotor shaft which is mounted in the base body in bearings for rotation. The electric machine has a pick-up element connected in fixed rotative engagement with the base body and which taps a voltage present on the rotor shaft. The pick-up element is electrically connected to the base body via a capacitor and/or an ohmic resistor. A capacitance value of the capacitor is at least 1 nF. A resistance value of the ohmic resistor is between 10 mO and 10 O.

Electric machine, rail vehicle and rail-mounted car set

The invention relates to a method for identifying dirt and/or dew on components of a voltage intermediate circuit converter. According to the invention, the temporal curve of a partial discharge pulsed current is detected at least during a precharging process of an intermediate circuit capacitor of the voltage intermediate circuit converter comprising at least one capacitor, wherein a frequency spectrum is calculated from said current pulse, and wherein depending of the result, a dirt warning and/or a dew warning is activated. Thus, the degree of dirt and/or dew of said voltage intermediate circuit converter can be determined at least during a charging process of an intermediate circuit capacitor of a voltage intermediate circuit converter, thereby preventing a breakdown including the consequences thereof.

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Buckenhof, Germany

Carsten Probol