Patent ID: 8403627

Claim:
A water pump ( 1 ) for pumping coolant in a low temperature and in a high temperature circuit comprising: a low temperature housing ( 2 ) including an internal low temperature spiral flow guide structure ( 3 ) and having a first mounting surface ( 4 ) extending in a first plane (E 1 ), a high temperature housing ( 5 ) including an internal high temperature spiral flow guide structure ( 6 ) and having a second mounting surface ( 7 ), a water pump rotor ( 8 ) for concurrently pumping low temperature coolant in the low temperature housing ( 2 ) via the low temperature spiral structure ( 3 ) through the low temperature circuit and high temperature coolant in the high temperature housing ( 5 ) via the high temperature spiral structure ( 6 ) through the high temperature circuit, the water pump rotor ( 8 ) comprising a low temperature rotor part ( 11 ) for pumping the coolant in the low temperature circuit and a high temperature rotor part ( 12 ) for pumping the coolant in the high temperature circuit, the low temperature rotor part ( 11 ) and the high temperature rotor part ( 12 ) being firmly joined to each other with a radially extending isolating gap ( 13 ) formed therebetween and a drive shaft ( 9 ) for driving the water pump rotor ( 8 ), and the first mounting surface ( 4 ) and the second mounting surface ( 7 ) being joined along the first plane (E 1 ) with an intermediate heat isolator ( 10 ) disposed between the low temperature spiral flow guide structure ( 3 ) and the high, temperature spiral flow guide structure ( 6 ).