Speed reducer and vertical roller mill driven by grinding roller

According to the speed reduction device and the vertical roller mill driven by the grinding roller, in the speed reduction device, a first planet wheel bearing is arranged in a first-stage planet wheel, so that power drives a first planet carrier through a first planet wheel shaft, the first planet carrier is meshed with a second sun wheel, the second sun wheel is meshed with a second planet wheel, and the second planet wheel is meshed with a second inner gear ring; and a second planet wheel bearing is arranged in the second-stage planet wheel, so that the power drives a second planet carrier through a second planet wheel shaft, and the second planet carrier outputs the power to the output flange. The speed reduction device is applied to the vertical roller mill, the hub is fixed to the output flange through the bolts, large torque can be guaranteed while the transmission efficiency is improved, and further improvement of the mill capacity is facilitated. The pressurizing device is arranged on the grinding ro