What are the types of reducers commonly used in industrial robots? What are the differences?

The reducer is one of the three important industrial robot components. It enables the servo motor to run at an appropriate speed and can accurately reduce the speed to the speed required by each component of the industrial robot while increasing the output torque. Compared with ordinary reducers, industrial robot joint reducers should have the characteristics of small size, light weight, high power, and convenient control. Industrial robots usually perform repetitive operations to perform the same process flow. In order for industrial robots to reliably perform process tasks and process quality, high requirements are placed on the accuracy and positioning accuracy of repeated positioning of industrial robots. Therefore, it is necessary to use reducers to improve and ensure the accuracy of industrial robots. What are the commonly used reducers in industrial robots? What are the differences?

Common reducer types for industrial robots

1.RV reducer

RV reducer is a new transmission mechanism developed from traditional cycloid gearbox and planetary gearbox. It has the advantages of compact structure, large transmission, long service life, stable precision and high efficiency. It has been widely used in articulated industrial robots. The power of the servo motor of the industrial robot is transmitted through the gearbox of the reducer input shaft, so that the large gear of the output shaft is linked to achieve the purpose of deceleration. The transmission ratio of the large and small gears is also the transmission ratio.

Working principle of RV reducer: A cylindrical pin is installed on the inner ring of the RV reducer housing. The eccentric movement of the RV transmission causes the pin and the RV transmission to assemble and connect. At the same time, multiple RV gearboxes are grabbed, increasing the load capacity. Since the RV has one less tooth than the pin, when the eccentric shaft rotates one circle, when the housing is fixed, the RV gear and the input shaft rotate one tooth in the same direction. The output can be the housing or the transmission shaft. When the housing is fixed, the transmission shaft is the output, and the output direction is the same. When the transmission shaft is fixed, the housing is the output, and the output direction is exactly the opposite.

2. Harmonic reducer

The harmonic reducer is a new type of gear reducer transmission mechanism commonly used in low-load industrial robots. It consists of a fixed rigid wheel, a flexible wheel and a wave generator, in which the number of teeth on the rigid wheel is slightly higher than that on the flexible wheel. The harmonic reducer has the advantages of large transmission, small size, partial parts, and high transmission efficiency. The transmission ratio of this single unit can reach 50-4000, and the transmission efficiency can reach 92%-96%. The harmonic reducer consists of three main components: a wave generator, a flexible transmission device, and a rigid transmission device. The wave generator transforms the flexible transmission into an adjustable elastic deformation and rigid transmission grid for motion and power transmission. The transmission can achieve a high reduction ratio, but its load, stiffness and life are not as good as RV, so it is mostly used in light-load robots.

Working principle of harmonic reducer: The harmonic reducer uses a flexible gearbox to generate an adjustable elastic deformation wave, so that the relative stepped teeth between the internal rigid gearbox and the flexible gearbox transmit power to achieve the deceleration goal. This type of transmission is fundamentally different from ordinary transmissions and has its own characteristics in grid theory, set calculation and structural design.

3. Planetary reducer

The planets in the planetary reducer are three planetary gears that rotate around the sun protector. The planetary reducer is a multifunctional reducer, also known as a servo planetary reducer, which can be used to reduce the speed of industrial robot motors while increasing the output torque. The planetary reducer has the advantages of small size, light weight, low noise, long life, large load capacity, and smooth operation.

Working principle of planetary reducer: When the solar transmission rotates under the power of the engine, the planetary gearbox connected to the planetary gearbox causes rotation. At the same time, because the other side of the planetary gearbox connects the main body to the empty internal gearbox on the inner wall, the planetary gearbox rolls in the direction of rotation through the rotation force, forming a "rotational" motion around the solar transmission.