Robot RV transmission is a new transmission mode, which has the advantages of small volume, light weight, large transmission ratio range, long life, stable accuracy, high efficiency, smooth transmission and so on. The RV reducer is the key mechanical structure of the robot, accounting for 38% of the total cost.
RV reducers feature two-stage reduction:
Primary stage: Planetary gear reducer with a 12-tooth input gear driving two 42-tooth gears, achieving a 3.5:1 reduction ratio.
Secondary stage: Differential gear mechanism where a large gear drives a CAM and crankshaft (3.5:1 turnover). A needle roller bearing on the crankshaft’s eccentric part supports the first RV gear, which swings via two cams. The second RV gear follows in staggered motion. With 40 teeth in the pin tooth housing and 39 on the RV gear, each crankshaft rotation moves the housing by 1 tooth, yielding a 40:1 reduction.
Total ratio: 3.5 × 40 = 140. Components like angular contact ball bearings, planetary brackets, oil seals, and bearing springs are sequentially installed.
In the RV reducer, angular contact ball bearings are often used to support the spindle and undertake the critical task of transmitting power. For example, in the input shaft and output shaft of the reducer, the angular contact ball bearing can ensure the accurate rotation and stable support of the shaft, ensure the efficient transmission of power, and withstand the load from different directions to adapt to the complex working conditions of the reducer. Tapered roller bearings are generally used to withstand large combined radial and axial loads. For example, in the planetary gear part of the reducer or some key parts that need to bear both radial and axial forces, tapered roller bearings can play their unique performance advantages to ensure the stable operation of the reducer under complex conditions such as heavy load and impact load.
Different types of RV reducer and different manufacturers, there may be some differences in the specific selection and application of bearings, but angular contact ball bearings and tapered roller bearings are the more common application types of RV reducer. The performance and quality of these bearings have a critical impact on the overall performance, accuracy, life and reliability of the RV reducer.
RV reducer is composed of cycloidal pin wheel and planetary bracket, with its small size, strong impact resistance, large torque, high positioning accuracy, small vibration, large reduction ratio and other advantages. It is widely used in industrial robots, machine tools, medical testing equipment, satellite receiving system and other fields. It is more commonly used in the robot harmonic transmission, with much higher fatigue strength, stiffness and life, and the precision of the return difference is stable, unlike harmonic transmission, as the use of time growth, the motion accuracy will be significantly reduced, many countries in the world high precision robot transmission more RV reducer. Therefore, the RV reducer has the development trend of gradually replacing the harmonic reducer in the high-precision robot transmission.
