Precision reducer
Reducer: a key component of the transmission system, with rich downstream applications

Reducer is a common mechanical transmission device, which is mostly used to reduce the rotational speed of the output end while increasing the torque at the output end. If reverse operation is performed, it is called a speed reducer. Reducer is a key component in robots, and the high speed and low torque output of servo motors do not meet the motion requirements of robots. Reducer can ensure the normal operation of robots.

According to different architectures and transmission principles, reducers can be divided into universal reducers, specialized reducers, and precision reducers. Among them, universal reducers are mainly small and medium-sized, modular, serialized, and widely used; Specialized reducers are generally large and extra large, and need to be customized according to different application scenarios; Precision reducers are lightweight, easy to control, and have high power output, mainly used in industries such as robotics and CNC machine tools.

In addition, reducers can be divided into single-stage and multi-stage reducers according to different transmission stages; According to the shape of gears, they can be divided into cylindrical gear reducers, bevel gear reducers, and cone and cylindrical gear reducers; According to the arrangement of transmission, it can be divided into expansion type, diversion type, and coaxial type reducers.

Precision reducers can be divided into harmonic reducers, RV reducers, and precision planetary reducers

Compared to traditional reducers, precision reducers have smaller backlash, higher precision, and longer service life, and are widely used in high-end fields such as robots and CNC machine tools. Precision reducers can be divided into harmonic reducers, RV reducers, precision planetary reducers, etc. The RV reducer consists of a first stage involute cylindrical gear planetary reduction mechanism and a second stage cycloidal pinwheel planetary reduction mechanism. Its characteristics are compact structure, low vibration, and low energy consumption. It is currently widely used in robots. Harmonic reducer is a structure that utilizes the elastic deformation waves of flexible components for power transmission transformation, including harmonic generator, flexible wheel, and steel wheel. It has a large transmission ratio and high transmission accuracy. The motion of a planetary gearbox is similar to that of the Earth rotating around the Sun, with a small volume, large load, and smooth operation.

RV reducer: high load, high stiffness, large volume

RV reducer, also known as "Rotary Vector Reducer", is a precision planetary gear reducer that uses a cycloidal pinwheel meshing mechanism as the core transmission component. RV reducers have the characteristics of high precision, high rigidity, and strong load capacity. Therefore, RV reducers are usually used in the joint drive of industrial robots, such as welding robots, assembly robots, handling robots, and other fields that require extremely high motion control.

In 1960, the concept and principle of RV reducers gradually took shape. In the 1980s, the introduction of computers further improved the accuracy and efficiency of RV reducer design, and RV reducers began modular and standardized production. Today, RV reducers have become key components of high-end equipment such as robot arms, precision machine tools, and semiconductor manufacturing equipment.

The first stage RV reducer has a compact structure, high precision, and rigidity; The secondary RV reducer has the characteristics of high efficiency, low noise, and low vibration; The torque and transmission capacity of the three-stage RV reducer are relatively high, with a high load-bearing capacity.

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

The harmonic reducer is mainly composed of three components: flexible wheel, wave generator, and steel wheel, among which the harmonic generator is the active shaft. The flexible wheel and steel wheel form a transmission shaft through meshing. Compared with general reducers, harmonic reducers have the characteristics of large transmission ratio, small volume, and small mass, and can be widely used in robot arms, wrists, hands, and other positions.

Wave generator: It consists 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 elastically deformed into an elliptical shape through ball bearings. Flexible wheel: A flexible thin-walled elastic component with an external gear ring, typically installed at the output end of a reducer. Rigid wheel: a rigid circular ring component with an internal gear ring, usually with two more gears than a flexible wheel, usually fixed on the reducer body.

Harmonic drive has the following major characteristics: 1) High precision: gear saw error and accumulated pitch error have a relatively even impact on rotational accuracy, with high position and rotational accuracy; 2) Large transmission ratio: The transmission ratio of single-stage harmonic gear transmission can reach i=30~500, and it only contains three core components with a relatively simple structure; 3) High load-bearing capacity: The contact between teeth is surface contact, with a large number of meshing teeth resulting in a smaller load per unit area, which can carry more weight; 4) Small size and light weight; 5) High transmission efficiency and long lifespan; 6) Smooth transmission, no impact, and low noise.

Compared to RV reducers, harmonic reducers have smaller backlash and smaller volume, but weaker load-bearing capacity. Therefore, RV reducers are more commonly used in high load areas, and their structures are complex and difficult to achieve large-scale production. In the light load field, harmonic reducers dominate.