Flow cooled coolant pump with wet rotor

Disclosed is a coolant pump (1) for a coolant circuit of an internal combustion engine. In an axial-flow area of ​​a pump housing, a motor chamber (20) with a pump motor (40) and an axially aligned pump shaft (50) is arranged. A flow channel (30) between an inlet chamber (11) and a pump chamber (12) surrounds the outer surface of the motor chamber (20) and tapers in the direction of the pump chamber (12) to the motor shaft (50) out so that the coolant as a sheath flow around the is guided motor chamber (20) and a pump impeller disposed therein (55) flows against axial when it enters the pump chamber (12). In the motor chamber a gap tube (60) coaxial with the motor shaft (50) between a rotor (45) and a stator (41) is arranged so that a portion of the refrigerant is branched off as a bypass flow in the gap tube (60) and, after a flow through the motor chamber (20) the shell stream whereafter the combined refrigerant from the pump impeller (55) in the pump chamber (12) is circulated is supplied again.