| 摘要 |
PURPOSE:To improve heat radiation and to uniform the efficiency of heat radiation in the longitudinal direction by inserting plural heat radiation fins having length shorter than that of a drum and having V-shaped sectios respectively between radical rims arranged between an inner cylinder for a bearing and a drum body so that the insertion pitches of the fins are increased in the direction from one end of the drum to the other end. CONSTITUTION:The inner cylinder 2 for the bearing and the outer cylinder 1 forming the drum body are concentrically and unitedly molded through plural radical coupling rims and the plural radiation fins 4 having length shorter than that of the drum and having V-shaped sections are inserted between the rims 3 arranged between the inner and outer cylinders 1, 2 so that the fin pitches are increased in stages by increasing the number of fins gradually in the direction from one end side of the drum to the other end, and the folded side edges 4a of the fins 4 and the outer side plates of both the blade plate parts 4b are joined and fixed to the outer periphery of the inner cylinder 2 and the inside of the outer cylinder 1 respectively. Thus, the surface temperature can be controlled sufficiently and uniformly in the longitudinal direction by sending air by a fan 7 from one end of the drum, so that no trouble such as overheat is generated in spite of long continuous use. Consequently, a fixing mechanism can be simplified and the copying machine can be reduced at its size. |
