Bearing lubricating structure of reduction gearbox

The utility model provides a bearing lubricating structure of a reduction gearbox, and belongs to the technical field of bearing lubrication. The reduction gearbox comprises a driving shaft and a driven shaft, wherein the driving shaft is mounted inside the reduction gearbox through a bearing; the bearing lubricating structure comprises a rotating part and a shaft sleeve, wherein the rotating part is positioned above a threaded section of the driving shaft and fixed after being integrally manufactured with or split from the driving shaft; the bearing is arranged on the rotating part; one or more shaft sleeves are arranged on the driving shaft in a sleeving way from the lower end surface of the bearing to a shaft section of the threaded section; an oil inlet is formed at one end part of the shaft sleeve, which is close to the threaded section of the driving shaft; an oil outlet device is arranged on the rotating part close to the upper end surface of the bearing; spiral grooves /a spiral groove are/is formed o