Anti-backlash mechanism for electromechanical linear actuator

An anti-backlash mechanism for engaging with a leadscrew, the leadscrew engaging with internal threads of a hollow shaft in a rotary motor, comprising:

• a main nut, mounted to bearings of the rotary motor, having an integral or attached collet with a set of longitudinal slits forming fingers, the collet tapering radially inward toward tips of the fingers at a specified taper angle, the main nut and collet provided with an internal thread for engaging with an external thread of the leadscrew;
• an adjustment nut, annular load spring, annular precision shim, and retaining ring sequentially fitting over the collet against the main nut, the adjustment nut, annular load spring and annular precision shim having a degree of longitudinal play between the main nut and retaining ring;
• and
• a pre-load nut with an internal tapered surface that mates with the collet fingers, the internal tapered surface having a specified taper angle that substantially matches that of the collet fingers, the pre-load nut housing the annular load spring and annular precision shim when screwed onto external threads of the adjustment nut by an amount that both compresses the load spring and applies radially inward force to the collet fingers against the leadscrew with an adjustable load dependent upon the amount that the pre-load nut is screwed down upon the adjustment nut.