本发明涉及一种风冷式塑胶挤出机行星减速装置,包括设置于箱体内并依次传动的输入轴、传动机构和输出轴,内置圆筒穿接于箱体的输出端并经法兰与箱体输出端端面连接,输出轴经两只第一轴承支承于内置圆筒,输出轴的伸出端套接有推力圆筒,推力圆筒经圆环盖固定连接于内置圆筒的外端面;圆筒端盖连接于箱体输入端,输入轴经两只第二轴承支承于圆筒端盖, The invention relates to an air-cooled plastic extruder planetary reduction device, which comprises an input shaft, a transmission mechanism and an output shaft which are arranged in the box body and are sequentially driven, the built-in cylinder pierces the output end of the box body and is connected with the flange The output end of the box body is connected with the output shaft, the output shaft is supported by the two first bearings in the built-in cylinder, the protruding end of the output shaft is sleeved with a thrust cylinder, the thrust cylinder is fixedly connected with the outer end surface of the built-in cylinder through the circular ring cover ; The cylinder end cap is connected to the input end of the box body, the input shaft is supported on the cylinder end cap through two second bearings,