Vacuum device and vacuum pump
A vacuum apparatus has a vacuum chamber provided with a gas inlet and a gas outlet, and mechanical vacuum pumps in a plurality of stages for reducing a pressure inside the vacuum chamber and maintaining the pressure-reduced state. The vacuum apparatus has an ejector pump ( 60 ) connected to a discharge port ( 57 ) of a screw pump (A) as the vacuum pump at the last stage among the vacuum pumps. The vacuum apparatus is reduced in power consumption and used in the semiconductor manufacturing field and so on.
1 . A vacuum apparatus comprising a vacuum chamber having a gas inlet and a gas outlet, and mechanical vacuum pumps in a plurality of stages, connected to said vacuum chamber, for reducing a pressure inside said vacuum chamber and maintaining a pressure-reduced state,
wherein said vacuum apparatus comprises a non-mechanical auxiliary pump, connected to a discharge port of the vacuum pump at the last stage in said vacuum pumps, for assisting a pressure reducing operation of said vacuum pump at the last stage and suppressing back diffusion from said discharge port.
2 . A vacuum apparatus according to claim 1 , wherein said auxiliary pump is an ejector pump additionally attached to said discharge port of said pump at the last stage.
3 . A vacuum apparatus according to claim 1 , wherein said auxiliary pump is an ejector pump incorporated in said pump at the last stage so as to form a device integral with said pump at the last stage.
4 . A vacuum apparatus comprising a vacuum chamber having a gas inlet and a gas outlet and mechanical vacuum pumps in a plurality of stages connected to said vacuum chamber for reducing a pressure inside said vacuum chamber and maintaining a pressure-reduced state,
wherein said vacuum apparatus comprises an ejector pump connected to a discharge port of the vacuum pump at the last stage in said vacuum pumps.
5 . A vacuum apparatus comprising a vacuum chamber having a gas inlet and a gas outlet, a first vacuum pump for maintaining the inside of said vacuum chamber to be reduced in pressure, a second vacuum pump connected at a subsequent stage of said first vacuum pump, and a third vacuum pump connected at a subsequent stage of said second vacuum pump, said vacuum apparatus characterized in that
said first vacuum pump is a turbomolecular pump or a thread groove pump, said second vacuum pump is a booster pump, and said third vacuum pump is a dry pump, and
an ejector pump is added to the inside or the outside of said third vacuum pump.
6 . A vacuum pump comprising an ejector pump portion at a discharge port exposed to the atmospheric side.
7 . A vacuum pump according to claim 6 , wherein said ejector pump portion is additionally attached to the outside of said vacuum pump.
8 . A vacuum pump according to claim 6 , wherein said ejector pump portion is incorporated in said vacuum pump.
9 . A vacuum pump according to claim 6 , wherein said vacuum pump is a screw pump or a Roots pump.
10 . A vacuum pump according to claim 7 , wherein said vacuum pump is a screw pump or a Roots pump.
11 . A vacuum pump according to claim 8 , wherein said vacuum pump is a screw pump or a Roots pump.