NEGATIVE PRESSURE PUMP AND NEGATIVE PRESSURE PUMP FOR NEGATIVE PRESSURE BOOSTER FOR VEHICLE

摘要

PROBLEM TO BE SOLVED: To provide a negative pressure pump into which moisture is hard to intrude by increasing the volume of a discharge chamber over the volume of a suction chamber.;SOLUTION: This negative pressure pump includes a suction chamber 110 on the inlet side of a pump part 50 and a second discharge chamber 98 on the outlet side of the pump part 50. The volume V5 of the second discharge chamber 98 is set larger than the volume V1 of the suction chamber 110. Therefor, even if the air including moisture enters the second discharge chamber during the stoppage of the pump, the air remains in the second discharge chamber, and does not flow into the pump part or the suction chamber.;COPYRIGHT: (C)2011,JPO&INPIT