Sealing mechanism for sealing a vacuum chamber

A combination of a vacuum chamber formed in a semiconductor producing apparatus and a sealing mechanism for sealing said vacuum chamber, said sealing mechanism comprising:

• a rotation shaft driven to be rotatable around its own axis and having an outer surface in the form of a cylindrical shape;
• a support member intervening between said vacuum camber and the atmosphere and rotatably supporting said rotation shaft to have said rotation shaft received therein, said support member having an inner surface in the form of a cylindrical hollow shape and first and second axial ends respectively extending in the atmosphere and said vacuum chamber, said inner surface of said support member being larger in diameter than the outer surface of said rotation shaft;
• a seal ring positioned between said rotation shaft and said support member to hermetically seal the gap between said rotation shaft and said support member;
• and
• a bearing positioned in the gap between said seal ring and said atmosphere, said rotation shaft being rotatably received in said support member through said bearing;
• said seal ring comprising an annular retaining member formed with an annular groove opening toward said atmosphere, and an annular spring member tightly received in said annular groove and retained and covered by said annular retaining member to resiliently solely bias said annular retaining member to expand radially outwardly in which
• said support member has an extension plane radially inwardly extending and flush with said second axial end, and in which said sealing mechanism further comprises an additional seal ring positioned between said rotation shaft and said support member in axial spaced relationship with said seal ring between said seal ring and said extension plane to seal the gap between said rotation shaft and said support member.