US Patent 7107827 Fuel vapor leak check module

A fuel vapor leak check module has a pressure sensor and a pump driven by a brushless motor. The pressure sensor is disposed at a place opposite to the inlet. A sensor room in which the pressure sensor is disposed communicates with the inlet of the pump through a pressure introducing passage and a pump-passage. Even if a pressure fluctuation arises at an inlet of the pump, a pressure fluctuation of the pressure in the fuel tank is restricted. Furthermore, the control circuit for the brushless motor is cooled by air flowing through a discharge passage. The sensor room is restricted from the discharge passage so that the discharged air hardly flows into the pressure room to enhance the accuracy of fuel vapor detection.