The RV reducer gearbox is developed on the basis of traditional cycloid planetary transmission. Its reduction structure consists of the first-stage planetary reducer and the second-stage cycloid pinwheel reducer. It uses at least two eccentric shafts to connect the secondary reduction mechanism. The housing and cycloid pinwheel are matched and driven by solid castings and steel components, which form a closed differential gear train. The RV reducer gearbox not only overcomes the shortcomings of general cycloid pinwheel transmission but also has a series of advantages such as high precision (backlash less than 1 arc minute), high rigidity, high durability, high output density (high torque and compact), wide reduction ratio range, and low vibration.