Roller screw bidirectional axial preloading structure

A roller screw bidirectional axial preloading structure, comprising:

• a screw having a thread structure formed on an outer surface thereof;
• a nut being fitted around the screw and having at least one annular grooved zone provided on an inner wall surface thereof;
• a roller unit being provided between the screw and the nut and including a plurality of first rollers and a plurality of second rollers;
• the first and the second rollers being arranged around the screw in a circumferentially interleaved manner;
• the first and the second rollers being provided on around respective outer circumferential surfaces with a plurality of annular teeth for meshing with the thread structure on the screw and the at least one annular grooved zone in the nut;
• a retainer unit being provided in the nut and including a first retainer and a second retainer, which are located at two ends of the roller unit;
• each of the first rollers having a first and a second outermost end section connected to the first and the second retainer, and each of the second rollers having a third and a fourth outermost end section connected to the first and the second retainer;
• a first gap being formed between each first outermost end section of the first rollers and the first retainer, and a second gap being formed between each fourth outermost end section of the second rollers and the second retainer;
• and the first gaps and the second gaps located at two opposite ends of the roller unit being arranged in a circumferentially interleaved manner;
• and
• two elastic elements being fitted in the nut to be separately located at two axially outer sides of the first and the second retainer;
• a retaining member being provided at an axially outer side of each of the two elastic elements to prevent the elastic elements from axially sliding out of the nut;
• whereby the two elastic elements can respectively apply an axially positive force on the first and the second rollers to form an interleaved, bidirectional, and axial preloading arrangement.