2, precision reducer: humanoid robot is essential

2.1 Precision reducer can be divided into harmonic reducer, RV reducer, precision planetary reducer

Compared with the traditional reducer, the precision reducer has small return clearance, higher precision and longer service life, and is widely used in high-end fields such as robots and digital control machine tools. Precision reducer can be divided into harmonic reducer, RV reducer, precision planetary reducer and so on. RV reducer is composed of the first stage involute cylindrical gear planetary reducer and the second stage cycloidal pinwheel planetary reducer, which is characterized by compact structure, low vibration and low energy consumption, and is widely used in robots. The harmonic reducer is a structure that uses the elastic deformation wave of flexible components for power transmission transformation, including harmonic generator, flexible wheel and steel wheel, which has a large transmission ratio and high transmission precision. The motion of the planetary reducer is similar to that of the Earth rotating around the sun, with small size, large load and smooth operation.

5X00453G01 2.2 RV reducer: high load, high stiffness, large volume

RV reducer, full name “Rotary VectorReducer”, is a precision planetary gear reducer, which uses a pendulum line pin wheel engagement mechanism as the core transmission component. RV reducer has the characteristics of high precision, high rigidity and strong load capacity, therefore, RV reducer is usually used in the joint drive of industrial robots, such as welding robots, assembly robots, moving robots and other fields with high requirements for motion control.

In 1960, the concept and principle of RV reducer gradually formed, into the 1980s, the introduction of computers made RV speed reducer design accuracy and efficiency further improved, RV reducer began modular standardized production, so far, RV reducer has become a key component of high-end equipment such as robot arms, precision machine tools, and semiconductor manufacturing equipment.

The first RV reducer has compact structure, high precision and rigidity. The two-stage RV reducer has the characteristics of high efficiency, low noise and low vibration. The three-stage RV reducer has larger torque and transmission capacity and higher load capacity.

5X00453G01

2.3 Harmonic reducer: small size, high transmission ratio, high precision

The harmonic reducer is mainly composed of three parts: flexwheel, wave generator and steel wheel, among which the harmonic generator is the drive shaft. The flexible wheel and the steel wheel are meshed to form the drive shaft. Compared with the general reducer, the harmonic reducer has the characteristics of large transmission ratio, small volume and small mass, and can be widely used in the robot forearm, wrist, hand and other positions.

Wave generator: composed of a flexible bearing and an elliptical CAM, the wave generator is usually installed at the input end of the reducer, the inner ring of the flexible bearing is fixed on the CAM, and the outer ring is formed by the elastic change of the ball. Flexwheel: Flexible thin-walled elastomer part with outer ring teeth, usually installed at the output end of the reducer. Rigid wheel: a rigid circular ring with an inner ring of teeth, generally two more gears than a flexible wheel, usually fixed to the reducer body.

5X00453G01 Harmonic transmission has the following characteristics: 1) high precision: gear tooth saw error and accumulated pitch error have an average effect on rotation accuracy, and position accuracy and rotation precision are high; 2) Large transmission ratio: the transmission ratio of single-stage harmonic gear transmission can reach i=30~500, and the structure is simple when only three core components are included; 3) High bearing capacity: the contact between teeth is surface contact, the number of meshing teeth is more, and the load per unit area is small, which can carry more weight; 4) Small size and light weight; 5) High transmission efficiency, long life; 6) Smooth transmission, no impact, low noise.

Compared with the RV reducer, the harmonic reducer has smaller back clearance and smaller volume, but the bearing capacity is weak. Therefore, RV reducer is more used in high load parts, its structure is more complex and difficult to achieve large-scale mass production, in the field of light load is dominated by harmonic reducer.