Helical gear and spiral bevel gear speed reducer

The utility model discloses a helical gear and spiral bevel gear speed reducer. The speed reducer comprises a box body, wherein a motor, a gear shaft, a linkage shaft and an output shaft are assembled on the box body, an output shaft of the motor is sleeved by a driving gear, a driven gear meshed with the driving gear is arranged on the gear shaft, spiral bevel gears meshed with each other are respectively arranged on the gear shaft and the linkage shaft, the output shaft is sleeved by an output gear, a linkage gear is arranged on the linkage shaft and meshed with the output gear, and roller bearings are arranged between the gear shaft and the box body, between the linkage shaft and the box body, as well as between the output shaft and the box body. Through the structure, the motor rotates to drive the gear shaft to rotate, and the gear shaft drives the output shaft to rotate through the linkage shaft, so as to realize the whole speed reduction process of the speed reducer. Therefore, the speed reducer provid