Reducer is generally used for transmission equipment with low speed and high torque. The motor, internal combustion engine or other power running at high speed mesh the reducer with the large gear on the output shaft through the small gear on the input shaft to achieve the purpose of deceleration. Ordinary people also have several pairs of gears to achieve the ideal deceleration effect based on the same principle The characteristics of gear reducer are: when transmitting power, it can split power; At the same time, the input shaft and output shaft are coaxial, that is, the output shaft and input shaft are arranged on the same main axis. Therefore, gear reducer transmission has been used to replace ordinary gear transmission as a speed reducer and speed change device in various mechanical transmission systems. The reducer is relatively large and can realize the synthesis and decomposition of motion. As long as the type of gear transmission and gear matching scheme are correctly selected, several gears can be used to obtain large transmission ratio. The transmission of gear reducer is only used to transmit motion, and its transmission ratio can reach thousands. It should be pointed out that when the transmission ratio is large, the gear transmission can still maintain the advantages of compact structure, small mass and small volume. In addition, it can also realize the synthesis and decomposition of motion and realize the complex motion with various velocity changes. The gear reducer has the advantages of small volume, small mass, compact structure and large bearing capacity. Due to the power split of gear transmission, the central wheel forms coaxial transmission, and the reasonable application of internal meshing gear pair can make the gear transmission structure very compact. In addition, since multiple wheels are evenly distributed around the center wheel to share the load, each gear bears a small load, and these gears allow a small modulus. In addition, the structure makes full use of the large bearing capacity of internal meshing and the allowable volume of the internal gear ring itself, which is conducive to reducing the external size, making it small in volume, small in mass, very compact in structure and large in bearing capacity. Generally speaking, the overall dimension and mass of gear transmission are about 1 / 2 ~ 1 / 5 of that of ordinary gear transmission (i.e. under the same load conditions) The transmission efficiency of gear reducer is due to the symmetry of gear transmission structure, that is, it has several evenly distributed wheels. The reaction force acting on the central wheel and rotating arm bearing can balance each other, which helps to improve the transmission efficiency. Under the conditions of appropriate transmission mode selection and reasonable structural layout, the efficiency can reach 0.97 ~ 0.99.
