Right-angle planetary reducer: an indispensable core component of industrial robots

In the field of mechanical transmission, the reducer is an intermediate device that connects the power source and the actuator. Usually, the small gear on the input shaft is meshed with the large gear on the output shaft to achieve the purpose of reducing the speed and transmitting greater torque. At present, mature and standardized reducers include: cylindrical gear reducer, turbine reducer, planetary reducer, planetary gear reducer, RV reducer, cycloid reducer, harmonic reducer. Since the 1980 s and 1990 s, with the development of emerging industries such as robotics, aerospace, medical equipment, etc., high-performance precision reducers with simple and compact structure, high transmission power, low noise, and stable transmission are required. Among them, RV reducer and harmonic reducer are two important right-angle planetary reducers.

The RV reducer has higher rigidity and rotation accuracy. Therefore, in the articulated robot, the RV reducer is generally placed in the position of heavy load such as the base, boom, shoulder, etc. The harmonic reducer is placed on the forearm, wrist or hand; Cartesian robots generally use right-angle planetary reducers.

An industrial robot is a general-purpose machine equipped with a memory device and an end effector, which can replace human labor to complete various movements or processes. Usually in production, it can replace workers to do some monotonous, frequent, repeated long-term operations, or work in dangerous and harsh environments. It can improve production efficiency and product quality, and is an effective solution for enterprises to supplement and replace labor. At present, the development of industrial robots is characterized by high speed, precision, compact body mechanism, multiple degrees of freedom, and increased rigidity. The key areas also require heavy load or fast response speed. For example, the load of welding robots in automobile production is mostly between 150-300Kg, while the assembly robots in the electronic field need to respond quickly to the parts on the assembly line.

The role of right-angle planetary reducer in industrial robots: The power source of industrial robots is AC servo motors, because its servo motors can achieve speed regulation through pulse signals. Industrial robots usually perform repetitive actions to complete the same process; in order to ensure that industrial robots can reliably complete process tasks in production and ensure process quality, the positioning accuracy and repeated positioning accuracy of industrial robots are very high. Therefore, RV reducer or harmonic reducer is needed to improve and ensure the accuracy of industrial robots. Another role of right-angle planetary reducers in industrial robots is to transmit greater torque. When the load is heavy, it is not cost-effective to blindly increase the power of the servo motor. The output torque can be increased through the reducer within the appropriate speed range. In addition, the servo motor is prone to heat and low-frequency vibration under low-frequency operation, which is not conducive to ensuring the accurate and reliable operation of industrial robots that work periodically for a long time.