Abstract: In an electrically driven coolant pump with an electromotor-pump unit an electronic control unit, generates a pulse-width modulated control signal for the pump depending on at least one engine operating parameter. In order to recognize irregularities and malfunctions in the pump's operation in due time, the control unit is connected with an error detector for the recognition of abnormal control signals and pump operating conditions and with a speed controlling device for the pump speed, with the error detector having an emergency device for the coolant pump.

Abstract: The invention relates to an electrically operated coolant pump with a rotor which is encompassed by a stator of the electromotor and comprises a rotor shaft with hollow design through which the liquid supply to the impeller is made, with the stator being arranged in a stator chamber of the motor housing and the rotor shaft being rotationally held in the motor housing, with the bearing of the rotor shaft being effected by way of roller bearings.In order to increase the efficiency and reduce the wear and tear of the bearings, it is proposed that at least one roller bearing is arranged as a leakproof roller bearing and sealing elements are integrated in the roller bearing cages, and that the stator chamber which is separated in a leakproof manner from the conveying liquid is provided with a dry design.

Abstract: A compact, quiet, electrically actuatable multiple-way valve, in particular for coolant circulation in an internal combustion engine, includes an inlet duct and at least two outlet ducts branching off from a collecting chamber, each outlet duct being respectively closable by a locking part. Each locking part is connected with an electrically triggerable actuating member which includes a temperature-sensitive, electrically heatable extensible material element.