Lubrication system for ballscrew actuator

A ballscrew assembly comprising:

• a ballnut having a first helical groove formed on a radially inner surface and defining an axis (X);
• a ballscrew disposed along the axis (X) within the ballnut, the ballscrew comprising a second helical groove formed on a radially outer surface and opposed to the first helical groove so as to form a helical raceway;
• a plurality of balls disposed in the helical raceway;
• a first seal disposed at a first axial end of the ballnut to seal between the ballscrew and the ballnut;
• and
• a second seal for selectively sealing between the ballscrew and a second axial end of the ballnut, the second seal comprising a ballscrew seal mounted for axial movement with the ballscrew, and configured to make sealing engagement with the ballnut when the ballscrew is in a first axial position relative to the ballnut to form a chamber between the first and second seals, but not to make sealing engagement with the ballnut when the ballscrew assembly is in a second axial position relative thereto.