Vertical speed reducer and leakproof sealing device for output shaft on vertical speed reducer

The vertical speed reducer comprises an outer shell and fixing plates fixed to the two ends of the outer shell, an output shell and an input shell are fixed to the two fixing plates in a penetrating mode respectively, outer supporting rings are arranged at the two ends of the output shell and the two ends of the input shell in an embedded mode, and fixing bearings are fixed to the middles of the outer supporting rings in a penetrating mode. Inner supporting rings are fixed to the middles of the fixed bearings in a penetrating mode, an input shaft is fixed to the middles of the two inner supporting rings in a penetrating mode, a small gear is arranged at one end of the input shaft in an embedded mode, an output shaft is fixed to the middles of the other two inner supporting rings in a penetrating mode, and a large gear is arranged at one end of the output shaft in an embedded mode. The edge of the centrifugal ring abuts against the inner side of the inclined ring, when the centrifugal ring and the input shaft