According to industry experts and associations, the precision reducers used in the robot industry can be divided into RV reducers, harmonic reducers and SPINEA reducers. The market share of the three is about 40%, 40. %, 20%. Among them, RV reducer and harmonic reducer are the most mainstream precision reducers for industrial robots.

RV reducer: large transmission ratio, high transmission efficiency, high motion accuracy, small return, low vibration, high rigidity and high reliability. In the articulated robot, the RV reducer is generally placed at a heavy load such as the base, the boom, and the shoulder.

Harmonic reducer: large transmission ratio, small outline, small number of parts and high transmission efficiency. In articulated robots, harmonic reducers are typically placed on the arm, wrist or hand.

It is estimated that by 2020, China will consume 190,000 robots per year. By 2020, the market share of robots will reach 50% (95,000 units), and in 2025, the domestic market share of robots will exceed 70%. In the next five years, this will provide Chinese manufacturers with more than $74 billion in potential markets for robotics and related services. With the rapid development of China's industrial robot application market, the market demand for industrial robots for speed reducers has also increased. In general, the number of reducers required for an industrial robot is 4-6. With the development of industrial robots in the future, CIC Consulting Industry Research Center predicts that by 2020, China's industrial robot reducer market will exceed 4 billion yuan, and the compound growth rate will be 30% in the next five years.

According to industry sources, the purchase price of a four international giants of precision reducers is 30,000 yuan to 50,000 yuan, and it is sold to domestic customers with a good relationship of about 70,000 yuan, and the average ordinary customer is about 120,000 yuan. The cost of precision reducers is more than double that of the international giants, and it can be seen how much the profit difference is between them.

The current status of the reducer in the domestic market

For a long time, the precision reducer technology for robots has been controlled by the United States, Germany, Japan, the Czech Republic and other countries. Among them, 75% of the world's precision reducer market is occupied by Hamernaco and Nabtesco of Japan, and Nabtesco is produced. RV reducers, accounting for about 60% of the total, Hamernaco produces harmonic reducers, accounting for about 15%.

From the cost point of view, the current cost structure of the global robot industry, about 35% is the reducer, about 20% is the servo motor, about 15% is the control system, the machined body may only account for about 15%, the other part is mainly the application . It can be seen that the reducer is a key factor that restricts the development of the robot industry. At present, the core technology of Chinese robots still lacks an overall breakthrough. As a result, the development of the robot industry in China's high-end equipment manufacturing industry is slow, and it can only rely on imported RV reducers.

The high proportion of key components imported will lead to high cost of domestic manufacturing robots. In particular, the speed reducer, the price of the domestic company to buy the reducer is nearly several times the price of foreign companies. In this way, it is difficult for domestically produced robots to form a price advantage. Only when the annual output is 500-1000 units, there is a certain scale effect. Therefore, if China wants to form a robot industrialization, get rid of the constraints of foreign robot companies, and win autonomy in the field of robotics, it must accelerate the localization of the reducer.

At present, there are still bottlenecks in capacity expansion, including toll gates, management, and technology. Japan's reducers have a delay in the delivery cycle. The longest supply cycle has reached more than 6 months. Nabo, Japan The supply cycle of Toscotec has been extended from the original 2-3 months to the current 4-6 months. The domestic reducer capacity cannot be doubled in a short period of time and cannot meet the expanding market demand. Therefore, the expansion is not only a problem faced by domestic reducers, but also one of the problems faced by Japanese reducers.

Domestic RV reducer gap

Technical gap of RV reducer

The technology required for RV reducers is very high. The core difficulty lies in the close cooperation of various processes.

Tooth surface heat treatment, which is the input condition, the stress residual under the rough machining precision, and the stiffness strength of the surface should be consistent during the heat treatment;

The processing precision, the outer surface of the heat treatment surface is hard and soft, and the processing removal amount is different, so that the variance of the performance of the exposed portion is the key;

Part symmetry, different parts should be consistent at different angles;

Group technology: how to cooperate with each other;

Assembly accuracy: such a high precision assembly;

The result of the total distribution of the above tolerances is wear and life.

Power aspect

Difficulties in simulation: After modeling the multi-body dynamics simulation of dynamics, it is possible to know the vibration of each order;

Nonlinear features, causing great differences, once the resonance point is near the working point, it is affected;

Coupling with the system integration, the operating point (rated speed) of the integrated robot as the excitation frequency will cause the component to be damaged. The range of system operation is often continuous speed regulation. The 6-axis robot always has one axis that may be re-rated. Near 20%, unless well designed and implemented;

The product parameters fluctuate greatly. In such a precision matching system, the clearance/interference fit is only a few times different, so the contact stiffness/meshing stiffness is several times different. The large change of the stiffness matrix causes the natural frequency fluctuation.

Life optimization and iteration aspects

A stable car and a vibrating car may have many times the lifespan. I also know where the life is going;

Some material things that do not go through the real environment full life cycle testing can not find the problem. Therefore, there must be a round of problems and then iterative design process.

At present, the problem faced by robots seems to be that 60% of the price can't be done, and 90% of the price makes 30% of the life. In fact, life itself is a sign of the level of the machinery industry.