OSCLLATING PORTION SUPPORTING CONSTRUCTION FOR SMALL- APERTURE DRIVE MACHINE

PROBLEM TO BE SOLVED: To provide a supporting construction for oscillating portion capable of effectively utilizing the internal space even for a guiding pipe having a small diameter and of oscillating with a high accuracy. SOLUTION: A guiding pipe 1 has two or more divided outer cylindrical bodies 31, 34, of which, one set of at least a pair of front and rear divided outer cylindrical bodies 31, 32 are coupled and supported in a freely oscillating manner by a plurality of oscillating jacks 36. One end 36a of the oscillating jack 36 is fixed to one 32 of the pair of divided outer cylindrical body 31, 32, and other end 36b of the oscillating jack 36 is spherically supported by the spherical supporting body 38a of the other divided outer cylindrical body 31. Moreover, the connecting portion of the pair of divided outer peripheral cylindrical bodies 31, 32 connected liquid tightly through seal member 35, and the seal member 35 is arranged near on the circular plane containing a plurality of the spherical supporting portion 38a in a state of the oscillating jack expanded by half stroke.