Driving mechanism with gas bearing

A driving mechanism, comprising:

• a rod-like member having a flange;
• a cylindrical member for accommodating therein said rod-like member, said cylindrical member defining an interior space divided by said flange into two substantially independent spaces, wherein a clearance is defined between said cylindrical member and said flange;
• a gas bearing for discharging air and supporting without contact said cylindrical member and said rod-like member relative to each other;
• a bearing housing connected to said cylindrical member and accommodating therein said gas bearing, said bearing housing having gas reservoirs defined at opposite ends of said gas bearing and in communication with the outside of said bearing housing through passageways, said bearing housing further including a plurality of interior partition walls provided at an opposite side of said gas bearing from said cylindrical member and having a clearance between said rod-like member, wherein adjacent partition walls define an interspace therebetween into which a vacuum is applied;
• and
• driving means for moving one of said cylindrical member and said rod-like member relative to the other, said driving means supplying a driving gas to the interior space of said cylindrical member.