Side entering stirrer capable of replacing mechanical seal on line

The utility model discloses a side entering stirrer capable of replacing a mechanical seal on line. The side entering stirrer comprises a base arranged on a stirrer body, a reducing motor, a stirring shaft and a stirrer, wherein a mechanical seal is fixed on the stirring shaft; a bearing block fixed with the base is arranged between the mechanical seat and the base; a sealing sleeve is connected to an end face, which is close to the side of the mechanical seal, of the bearing block; an annular part of the sealing sleeve stretches into the bearing block and is in sealing fit with an inner hole of the bearing block; a supporting ring which slides relative to the stirring shaft is arranged between the inner hole of the annular part of the sealing sleeve and the stirring shaft; a locking sleeve fixed with the stirring shaft is arranged between the supporting ring and the inner side face of the bearing block; and a sealing ring pressing the inner side face of the bearing block after the stirring shaft moves to the body direction is arranged on the side face of the locking sleeve. According to the stirrer disclosed by the utility model, the sealing sleeve pushes the locking sleeve to drive the whole stirring shaft to move into the axial body, and reliable sealing between the locking sleeve and the bearing block is realized by virtue of the effect of the sealing ring, so that the mechanical seal is replaced and maintained on line.