VACUUM PUMP MECHANISM

Provided is a vacuum pump mechanism capable of suppressing occurrence of needless drive torque. A suction port 35 arranged at a housing 3 is connected to a brake master back 52 of a brake booster, and an oil regulating unit 60 capable of adjusting a quantity of lubricating oil flowing through a lubricating oil supply passage 44 when the brake master back 52 reaches a predetermined negative pressure. Accordingly, when the brake master back 52 reaches the predetermined negative pressure, the oil regulating unit 60 adjusts the quantity of lubricating oil flowing through the lubricating oil supply passage 44 to a reduced quantity or zero, whereby a load exerted by the lubricating oil to a vane 8 and the like of a vacuum pump 1 can be reduced than before. Therefore, occurrence of a needless drive torque at the vacuum pump 1 can be suppressed.