ENTRANCE OF MOVING ROD INTO PRESSURE TIGHT CHAMBER Russian patent published in 2011 - IPC F16J15/00 

FIELD: machine building.

SUBSTANCE: entrance consists of cylinder case inside of which there is installed cylinder fluoroplastic bushing with internal diametre facilitating sliding fit on rod. The case has an intermediate cavity for autonomous gas pumping-out. The bushing is shaped and consists of a cylinder with external diametre corresponding to internal diametre of the cylinder case and of two opposite directed truncated cones connected to the cylinder and symmetrical relative to plane perpendicular to axis. Vertexes of the cones have diametre less, than internal diametre of the cylinder case. Also, there is an intermediate cavity formed with two circular grooves symmetrical relative to plane of symmetry correspondingly on internal and external sides of a cylinder part of the bushing. The grooves are connected with at least one channel, axis of which is in plane of symmetry. Additionally, the entrance includes circular flexible elements located outside of the bushing in the region of vertexes of their conic parts; the elements are designed to hold internal surface of the bushing down to surface of the rod The circular flexible elements can be made out of vacuum rubber.

EFFECT: minimal leakage into chamber at rotation and travel of rod.

3 cl, 1 dwg