Linear motion rotary union

A linear movable rotary union comprising,

• a driving shaft comprising a plurality of fluid supply paths;
• a hollow middle housing surrounding an outside of the driving shaft and comprising a plurality of first through holes in a sidewall;
• a plurality of first sealing members provided between the middle housing and the driving shaft to prevent leakage of a fluid;
• a hollow outer housing surrounding an outside of the middle housing and comprising a plurality of second through holes in a sidewall;
• and
• a plurality of second sealing members provided between the middle housing and the outer housing to prevent leakage of the fluid,
• wherein the driving shaft is provided to be capable of rotational motion in the middle housing, and the middle housing is provided to be capable of reciprocating motion in an axial direction in the outer housing, and
• wherein the first sealing member is a lip seal with a curved lip formed on an inner periphery of an annular sealing.

A linear movable rotary union comprising:

• a driving shaft comprising a plurality of fluid supply paths;
• a hollow middle housing surrounding an outside of the driving shaft and comprising a plurality of first through holes in a sidewall;
• a plurality of first sealing members provided between the middle housing and the driving shaft to prevent leakage of a fluid;
• a hollow outer housing surrounding an outside of the middle housing and comprising a plurality of second through holes in a sidewall;
• and
• a plurality of second sealing members provided between the middle housing and the outer housing to prevent leakage of the fluid, and
• wherein the driving shaft is provided to be capable of vertical motion in an axial direction in the middle housing, and the middle housing is provided to be capable of rotational motion in the outer housing.