Part positioning device for assembling planetary gear reducer

The invention discloses a part positioning device for assembling a planetary gear speed reducer, and relates to the technical field of mechanical assembling. The part positioning device for assembling the planetary gear reducer is high in positioning precision and comprises a bevel table, the bottom end of the bevel table is fixedly connected with four supporting columns distributed at equal intervals in the circumferential direction, the top end of the bevel table is fixedly connected with a flat plate frame, a spherical adjusting block is rotatably connected into the flat plate frame, and a concave disc is slidably connected into the bevel table. A first reset spring is connected between the concave disc and the bevel table. A gear ring of a planetary gear is placed on the carrying disc, the spherical adjusting block is controlled to rotate to adjust the state of the carrying disc according to the conditions of the transverse gradienter and the vertical gradienter, then it is ensured that the gear ring of t