The invention discloses a power part structure of a cogging mill. The power part structure comprises a power motor, the output end of the power motor is connected with a power
reducer and then is connected with a
herringbone gear seat through a coupler, and the two output ends of the
herringbone gear seat are connected with the end of a lower roll and the end of an upper roll through composite connecting shafts. The power part structure is characterized in that the end of an input shaft of the
herringbone gear seat is connected and provided with a limiting sleeve and a connecting sleeve, the connecting sleeve and the input shaft of the herringbone gear seat are in transmission fit through gear meshing, and the connecting sleeve is fixedly connected with an output shaft of the power
reducer through a
flange and a
flange protrusion arranged between the connecting sleeve and the output shaft of the power
reducer and a reaming bolt. According to the power part structure of the cogging mill, mounting and
butt joint of the output shaft of the power reducer and the input shaft of the herringbone gear seat can be facilitated, and assembling convenience is improved; meanwhile, the clearance of a connecting bolt and connecting holes in a coupler can be adjusted and eliminated conveniently, transmission reliability and stability are guaranteed, and the smooth work of the power part is guaranteed.