Speed reducer provided with oil collecting, lubricating and clearance eliminating structure

The invention discloses a speed reducer provided with an oil collecting, lubricating and clearance eliminating structure. The speed reducer comprises a speed reducer shell, a gear transmission mechanism and an oil collecting device. The speed reducer further comprises a first belleville spring and a second belleville spring, wherein the first belleville spring is used for applying axial thrust to a first bevel gear, and the second belleville spring is used for applying axial thrust to a fourth bevel gear. The oil collecting device comprises a circular pipe body, a partition board, an oil storage cavity, an oil inlet and an oil outlet. When the gears are abraded, the belleville springs can automatically push the first bevel gear and the fourth bevel gear to move in the axial direction, so that a gear fit clearance caused by frictional abrasion is eliminated; in addition, the oil collecting device is arranged on the end faces of gear bodies, the section, below the gears, of the circular pipe body in the oil collecting device is immersed into lubricating oil during work, the lubricating oil enters the oil storage cavity through the oil inlet, the lubricating oil in the oil storage cavity rotates along with the gears so that part of the lubricating oil can be carried into a gear engagement area to be used for lubricating, and accordingly the lubricating and cooling effect on the gears can be improved, and the service life of the gears is prolonged.