Abstract: The present invention discloses a monitoring device for an electric machine, comprising a first detection apparatus which is configured to detect electrical power supplied to the electric machine, comprising a second detection apparatus which is configured to detect theoretical mechanical power output by the electric machine on the basis of a commutation of the electric machine, and comprising a calculation apparatus which, on the basis of the detected electrical power and of the detected theoretical mechanical power, is configured to calculate an efficiency of the electric machine and to emit an error signal if the calculated efficiency is greater than 1. The present invention further discloses a control device for an electric machine and a method for monitoring an electric machine.

Abstract: A method and a device for operating a closed-loop or open-loop speed-controlled electric motor of a fan drive, which motor is connected to an on-board system voltage of a motor vehicle and the motor speed of which is set to a defined first desired speed, wherein, if the on-board system voltage fluctuates, the motor speed is set to a desired speed that is lower compared with the first desired speed.

Abstract: The present invention discloses a monitoring device for an electric machine, comprising a first detection apparatus which is configured to detect electrical power supplied to the electric machine, comprising a second detection apparatus which is configured to detect theoretical mechanical power output by the electric machine on the basis of a commutation of the electric machine, and comprising a calculation apparatus which, on the basis of the detected electrical power and of the detected theoretical mechanical power, is configured to calculate an efficiency of the electric machine and to emit an error signal if the calculated efficiency is greater than 1. The present invention further discloses a control device for an electric machine and a method for monitoring an electric machine.

Abstract: A plain bearing of a shaft, in particular of an electric-motor drive unit of a motor vehicle, contains a first plain bearing part that surrounds the shaft and a second plain bearing part connected axially to the first plain bearing part. The thermal expansion coefficient of the second plain bearing part is greater than the thermal expansion coefficient of the first plain bearing part.

Abstract: According to a method for driving a converter (4) in accordance with a period commutation pattern, a transition region (25) is provided between a sinusoidal commutation region (21) and a block commutation region (22) in the context of the commutation pattern, in which transition region (25) a phase voltage (<UL1>) output by the converter (4) is set in temporally constant fashion for a first subsection (t1) of each half-cycle (P1, P2) in the manner of block commutation, while the phase voltage (<UL1>) is set in temporally varying fashion for a second subsection (t2, t3) of the half-cycle (P1, P2) in the manner of sinusoidal commutation. An apparatus (5) which is suitable for carrying out the method has a control unit (6) which is designed to generate a switching signal (PWM) for the converter (4) in accordance with the above-described method.

Abstract: Injectors each having a piezo actuator are assigned to cylinders of an internal combustion engine. A regulator device is configured for furnishing a cylinder-specific controlled variable and a command variable to a controller whose primary manipulated variable is a variable representing an electrical power supplied to the piezo actuator during a control cycle. A manipulated variable splitting unit is provided whose input variable is a regulator-determined regulator value of the primary manipulated variable and is configured for determining a total value of the primary manipulated variable according to the regulator value. It is also configured for splitting the total value into a primary value of the primary manipulated variable and into a secondary value of a secondary manipulated variable according to a lower and/or upper threshold value of the total value.

Abstract: Injectors each having a piezo actuator are assigned to cylinders of an internal combustion engine. A regulator device is configured for furnishing a cylinder-specific controlled variable and a command variable to a controller whose primary manipulated variable is a variable representing an electrical power supplied to the piezo actuator during a control cycle. A manipulated variable splitting unit is provided whose input variable is a regulator-determined regulator value of the primary manipulated variable and is configured for determining a total value of the primary manipulated variable according to the regulator value. It is also configured for splitting the total value into a primary value of the primary manipulated variable and into a secondary value of a secondary manipulated variable according to a lower and/or upper threshold value of the total value.