A speed reducer is one of the three essential components of an industrial robot. It enables servo motors to operate at appropriate speeds and accurately reduces the speed to the required level for each component of the robot, while simultaneously increasing output torque. Compared to ordinary speed reducers, industrial robot joint speed reducers should be small in size, lightweight, powerful, and easy to control. Industrial robots typically perform repetitive operations to execute the same technological processes. To ensure reliable execution of process tasks and maintain process quality, high requirements are placed on the accuracy and precision of repeated positioning. Therefore, it is necessary to use speed reducers to improve and ensure the accuracy of industrial robots. What are the two types of speed reducers commonly used in industrial robots? What are their differences?
Common types of reducers for industrial robots
1. RV reducer
The RV reducer is a new type of transmission mechanism developed from traditional cycloidal gearboxes and planetary gearboxes. It boasts advantages such as compact structure, high transmission capacity, long service life, stable precision, and high efficiency. It is widely used in articulated industrial robots. The power of the industrial robot's servo motor is transmitted through the gearbox on the reducer's input shaft, thereby engaging the large gear on the output shaft to achieve speed reduction. The transmission ratio between the large and small gears is also the gear ratio.
RV reducer working principle: 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. Simultaneously, multiple RV gears engage, increasing load capacity. Since the RV gear has one less tooth than the pin, when the eccentric shaft rotates one revolution, the RV gear and input shaft rotate one tooth in the same direction when the housing is fixed. The outlet can be either the housing or the drive shaft. When the housing is fixed, the drive shaft is the output, and the output direction is the same. When the drive shaft is fixed, the housing is the output, and the output direction is exactly opposite.
2. Harmonic reducer
Harmonic reducers are a new type of gear reducer transmission mechanism commonly used in low-load industrial robots. They consist of a fixed rigid wheel, a flexible wheel, and a wave generator, with the rigid wheel having a slightly higher number of teeth than the flexible wheel. Harmonic reducers offer advantages such as high transmission capacity, small size, fewer components, and high transmission efficiency. A single unit can achieve a transmission ratio of 50-4000 and a transmission efficiency of 92%-96%. A harmonic reducer comprises 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 electrical transmission. While gearboxes can achieve high reduction ratios, their load capacity, stiffness, and lifespan are not as good as RVs (Remote Drives), therefore they are mostly used in light-load robots.
Harmonic reducer working principle: The harmonic reducer uses a flexible gearbox to generate an adjustable elastic deformation wave, which transmits power through the relative stepped teeth between the internal rigid gearbox and the flexible gearbox, achieving the deceleration target. This type of gearbox is fundamentally different from ordinary gearboxes, and has its own characteristics in terms of mesh theory, ensemble calculation, and structural design.
3. Planetary gear reducer
The planets in a planetary reducer are three planetary gears that rotate around a solar protection device. A planetary reducer is a multi-functional reducer, also known as a servo planetary reducer, used to reduce the speed of industrial robot motors while increasing output torque. Planetary reducers have advantages such as small size, light weight, low noise, long lifespan, high load capacity, and smooth operation.
What are the two types of reducers commonly used in industrial robots? What are the differences between them? The working principle of a planetary reducer: When the solar-powered gearbox rotates under the power of the engine, connecting the planetary gearbox to the solar gearbox causes rotation. Simultaneously, 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 due to rotational force, forming a "rotational" motion around the solar-powered gearbox.
