Technical analysis of precision reducers commonly used in industrial robots

An industrial robot is a general-purpose machine equipped with a memory device and an end effector that can complete various movements or processes to replace human labor. Usually in production, it can replace workers to do some monotonous, substitution and repetitive operations, or operations in dangerous and harsh environments. It can improve production efficiency and product quality, and is an effective plan for companies to supplement and replace labor. At present, the development of industrial robots is characterized by high speed, accuracy, compact housing mechanism, multiple degrees of freedom and improved rigidity. Key areas also require heavy loads or fast response speed. For example, most of the electric welding robots produced by the automobile have a load between 150-300Kg, while the assembly robots in the electronic field need to respond quickly to the accessories on the assembly line. In the field of mechanical transmission, the reducer is an intermediate device that connects the power source and the actuator. Usually, it transfers the high-speed power of the electric motor, internal combustion engine, etc. through the small gear on the input shaft and the large gear on the output shaft to achieve the purpose of speed reduction. At present, mature and standardized reducers are: cylindrical gear reducer, turbine reducer, planetary reducer, planetary gear reducer, RV reducer, cycloid reducer and harmonic reducer. . Since the 1980s and 1990s, under the development needs of emerging industries such as aerospace, robotics and medical equipment, high-performance precision reducers with simple and compact structure, high transmission power, low noise, and stable transmission are required, among which RV reducers are harmonious Wave reducers are two important reducers in precision reducers. RV (rotating vector) reducer Since occupying the market in 1986, due to its large transmission ratio, high transmission efficiency, high motion accuracy, and hysteresis, the RV reducer has been developed on the basis of cycloid pin wheel transmission, with two-stage reduction and center disc support. structure. The advantages of small size, low vibration, high rigidity and high reliability are the "queen" reducers for robots. Harmonic reducer The harmonic reducer consists of three parts: harmonic generator, flexibility theory and rigid wheel. Its working principle is that the harmonic generator makes the flexible wheel produce controllable elastic deformation, and the power is transmitted by the ion of the flexible wheel and the rigid wheel. The harmonic reducer has a large transmission ratio, a small outline, a small number of parts and a high transmission efficiency. The single transmission ratio can reach 50-. And achieve the purpose of deceleration; according to the different wave generators, there are cam type, roller type and eccentric disc type. 4000, and the transmission efficiency is as high as 92%-96%. Planetary reducer The planetary reducer is small in size, light in weight, high in carrying capacity, long, stable in operation and low in noise. It has the unique and useful characteristics of power splitting and multi-tooth rotor; it is an industrial product with a wide range of uses, and its performance can be distinguished from other military grade planetary reducer products, but it has the price of industrial grade products and is widely used in industrial occasions. . The role of precision reducer on industrial robots The power source of an industrial robot is generally an AC servo motor. Because it is driven by a pulse signal, the servo motor itself can realize speed regulation. Why do industrial robots need a reducer? Industrial robots usually perform repetitive actions to complete the same process; in order to ensure that industrial robots can reliably complete tasks in production and ensure process quality, the positioning accuracy and repeated positioning accuracy of industrial robots are very high. Therefore, to improve and ensure the accuracy of industrial robots, RV reducers or harmonic reducers are needed. Another role of precision reducers in industrial robots is to transmit gears that change speed. When there is a load, it is not cost-effective to blindly increase the power of the servo motor. You can increase the output budget through a reducer within a suitable speed range. Maximum, the servo motor is prone to heat and vibration during operation, which is not conducive to ensuring accurate and reliable operation of industrial robots that work continuously and continuously. The existence of the precision reducer makes the servo motor run at a suitable speed, and accurately reduces the steering to the speed required by each part of the industrial robot, and improves the rigidity of the mechanical body while converting the torque. Robot joint reducers are required to have the characteristics of short transmission chain, small size, high power, light weight and easy control. There are