Single-nut planetary roller screw rod mechanism capable of simultaneously eliminating axial clearances on two sides

The invention discloses a mechanical device through which rotary motion and linear motion can be mutually transformed, in particular relates to a single-nut planetary roller screw rod mechanism capable of simultaneously eliminating axial clearances on two sides. According to the mechanism, a contraction disk component for radially compacting a long shaft roller 7 and a hollow roller 8 is arranged at the end of the roller consisting of the long shaft roller 7 and the hollow roller 8, and threads of the long shaft roller 7 and the hollow roller 8 are tightly clamped with threads of a screw rod 14 and a nut 2 respectively, so that the axial clearances on the two sides can be simultaneously eliminated. By the mechanism, the center distance and the bearing capacity cannot be changed, and the roller can be conveniently assembled; the axial clearances can be adjusted through the contraction disk at the shaft end, so that the axial clearances can be adjusted conveniently again after screws work for a long term and are worn; an idling or skidding phenomenon caused by the axial clearances is solved; the transmission accuracy is effectively improved, thread meshing impact is reduced, the bearing capacity is guaranteed, and the overall transmission efficiency is improved.