Patent ID: 8267678
Filing Date: 2012-09-18
Classification: F04C

Abstract:
1. A vane type vacuum pump, comprising a housing provided with a nearly circular pump chamber, side plates sealing opposing end surfaces of this housing, a rotor rotating at a position eccentric to the center of said pump chamber, a vane reciprocating along a groove formed in the diameter direction of the rotor and rotating while partitioning the pump chamber into a plurality of spaces, and an escaping groove provided in the vicinity of an air intake passage through which the air is sucked into said pump chamber and communicating a space on the front side and a space on the back side of the rotational direction of the vane at the time of the reverse rotation of the vane, thereby allowing the lubricating oil to escape into the space on the back side from the space on the front side, wherein said escaping groove is provided in the side plate, and moreover, a wall surface of said escaping groove which is on the back side of the rotational direction of the vane at the time of the reverse rotation of said vane is made into an inclined surface whose opening side is further expanded than a bottom of the escaping groove.