Arrangement for controlling the operation of a cooling system in an automotive vehicle

A cooling-medium compressor, comprising, in combination, a stator housing having a housing chamber defined by an interior wall;

• a rotor mounted for rotation in the housing chamber, the outer surface of the rotor and the interior wall of the housing together defining between themselves crescent-shaped working spaces, the rotor having a plurality of generally radially oriented guide slits, the rotor further including sliding vanes in the guide slits guided by the latter for generally radial reciprocation between radially extended and radially retracted positions within the guide slits, the sliding vanes dividing the crescents-shaped working spaces into individual cells;
• and means for arresting the vanes in the retracted positions thereof, at least some of said vanes being provided with such arresting means, but at least one of the vanes not being provided with such arresting means, the number of crescent-shaped working spaces being equal to n, and the n crescent-shaped working spaces being arranged point-symmetrically with respect to one another relative to the rotation axis of the rotor, there being a plurality of groups of sliding vanes, each group of sliding vanes consisting of n vanes likewise arranged point-symmetrically with respect to one another relative to the rotation axis of the rotor, all the vanes of at least one group being provided with such arresting means, and all the vanes of at least one group not being provided with such arresting means.