Abstract: The invention relates to a method and a device for operating a drive device. According to the invention, it is provided that the lower speed limit and the upper speed limit of a critical speed range of the drive device are determined when operating the drive device, that the target speed of the drive device is determined and that the operation of the drive device is done at one of the speed limits if the target speed is within the critical speed range. Through this procedure, it is for example avoided that the drive device is operated in a speed range in which the environment of the drive device or the device itself is excited into characteristic vibrations that are undesirable noise and/or vibrations.

Abstract: The invention relates to a method and a device for operating a drive device. According to the invention, it is provided that the lower speed limit and the upper speed limit of a critical speed range of the drive device are determined when operating the drive device, that the target speed of the drive device is determined and that the operation of the drive device is done at one of the speed limits if the target speed is within the critical speed range. Through this procedure, it is for example avoided that the drive device is operated in a speed range in which the environment of the drive device or the device itself is excited into characteristic vibrations that are undesirable noise and/or vibrations.

Abstract: An electrical machine according to the related art comprises a rotor shaft. The rotor shaft must be installed as a separate component.

Abstract: A device for heating a passenger space in a power vehicle comprises a main passage for supplying air, an intermediate passage associated with the main passage and branching into side passages connected with a passenger space, a heat exchanger, a branching passage leading from the main passage over the heat exchanger, a guiding element movable between and fixable in at least two end positions for air to connect the branching passage with the main passage and to separate the former from the latter so that in a flow direction of the air the air enters behind the heat exchanger in the intermediate passage, a blowing nozzle opening in a passenger space and connected with the intermediate passage, the intermediate passage being subdivided in partial passages, one of the partial passages being connected with the blowing nozzle while the other of the partial passages merging into the side passages, the guiding element in its operative position in which it connects the branching passage with the main passage opens a c