Coolant pump for an internal combustion engine

A coolant pump for an internal combustion engine, the coolant pump comprising:

• a delivery duct;
• a drive shaft;
• a coolant pump impeller arranged on the drive shaft so as to rotate jointly therewith, the coolant pump impeller being configured to convey a coolant;
• a control slide which is configured to be adjustable so as to control a throughflow cross-section of an annular gap arranged between an outlet of the coolant pump impeller and the surrounding delivery duct, the control slide comprising a first pressure chamber arranged on a first axial side of the control slide facing away from the coolant pump impeller and a second pressure chamber arranged on a second axial side of the control slide facing the coolant pump impeller;
• a connecting duct;
• a control pump comprising a control pump impeller which is arranged at the drive shaft so as to rotate jointly therewith, and a flow duct which is configured so that a pressure can be generated by a rotation of the control pump impeller, the flow duct comprising an outlet and being fluidically connected via the connecting duct to the second pressure chamber;
• a pressure duct configured to fluidically connect the outlet of the flow duct to the first pressure chamber of the control slide;
• and
• a valve configured to open and to close a throughflow cross-section of the pressure duct.