Patent ID: 6659747
Filing Date: 2003-12-09
Classification: F04C

Abstract:
A vacuum pump that draws gas by operating a gas conveying body in a pump chamber through rotation of a rotary shaft, the vacuum pump comprising:an oil housing member, wherein the oil housing member forms an oil zone adjacent to the pump chamber, and the rotary shaft has a projecting section that projects from the pump chamber to the oil zone through the oil housing member; an annular shaft seal, which is located around the projecting section to rotate integrally with the rotary shaft, wherein the shaft seal has a first seal forming surface that extends in a radial direction of the shaft seal; a second seal forming surface, which is directly formed on the oil housing member, wherein the second seal forming surface opposes the first seal forming surface and is substantially parallel with the first seal forming surface; and a labyrinth seal, which is located between the first and second seal forming surfaces.