Apparatus for moving motor-operated seat rail

An apparatus for moving a motor-operated seat rail having a moving rail and a fixed rail extending along an axial direction, the apparatus comprising:

• a lead screw having a first outer circumferential surface;
• a mounting bracket having an outer surface and mounting opposite ends adapted to be combined with the moving rail, the lead screw passing through a central portion of the mounting bracket so that the mounting bracket moves along the lead screw;
• and
• a spindle nut engaged with the lead screw through a screw engagement and having a first end and a second end, the first end being rotatably held on the mounting bracket such that the first end rotates relative to the mounting bracket, the second end passing through the central portion of the mounting bracket and extending along the axial direction, the second end having a first inner circumferential surface defining an inner diameter being elastically reducible so that the first inner circumferential surface comes into close contact with the first outer circumferential surface of the lead screw.