According to the mechanical design course design table 14-4, choose the LX3 elastic pin coupling. Its nominal torque is 1250n. M, and the diameter of the motor shaft is 19mm, so the aperture of the coupling should not be too small. Take = 19mm, half coupling length L = 82mm, half coupling and shaft hub hole length 60mm.The HL1 elastic pin coupling is selected as the auxiliary screw shaft of the axial rolling screw. Its nominal torque is 1,250000. The diameter of the half coupling is 19mm and the length is 42mm.The LX3 type elastic pin coupling is selected as the radial rolling screw shaft. The nominal torque is 1,250,000, the diameter of the half coupling is 19mm, and the length of the half coupling is 42mm.