Title: Eccentric screw assembly, processing time 11h, the material of each part is 45 steel. On the C620 lathe, the parts are machined using a four-jaw chuck. 1. Eccentric screw assembly (Fig. 1) Characteristic analysis The assembly drawing is assembled as usual, and it is difficult to ensure the tolerance of 136±0.05mm and 69±0.05mm after assembly. Tolerances and proper trimming must be carefully designed and assigned in advance. From the analysis of each part: to ensure that 136 ± 0.05mm can be trimmed eccentric sleeve 2; to ensure that 69 ± 0.05mm can be trimmed sleeve 3, because trapezoidal nut 5, body 4 and small nut 1 have tolerance requirements on their length So be considerate.