Differential roller screw has the characteristics of simple structure, high precision, high stiffness, good wear resistance, and long service life. It adopts a rolling arrangement of multiple rows of ball bearings, reducing frictional resistance and improving transmission efficiency. At the same time, the ball arrangement of the differential roller screw has a certain gap in both axial and radial directions, which can effectively absorb thermal expansion and vibration, ensuring transmission accuracy and stability. The RVD4X0.5 differential planetary roller screw pair is mainly used in dexterous hand transmission mechanisms, achieving finger joint bending and extension through the linear motion of the nut.