Reduction gear with seal rapid-changing function

A quick sealing change reducer is provided. On the output shaft of the reducer is provided with a quick sealing change device for changing the sealing lubricant mode of the reducer output shaft to the O-shaped sealing loop from the original oil-sealing airproof mode, thus quickly change the ineffective sealing loop. Using the clearance of the coupling section quickly changes the ineffective sealing loop under the condition of not disassembling the coupling. The main component of this utility model is adopting the expanding and tightening connection mode to fix the shaft disc on the reducer output shaft and forms sealing surface by matching with the inner hole of the shell. On the shaft disc is provided with two paths of O-shaped sealing loop so as to enhance the reliability of the sealing. The utility model is characterized in that: no disassembling of coupling of the reducer output shaft is required but quickly changes and replaces ineffective sealing loop, thus, saves time and power as well as energy and causes no influence to the normal manufacturing of mine.