Today, the "robot concept stocks" have staged a comeback, with several sub-sector indices reaching new all-time highs during trading. Despite a slight pullback in the afternoon, institutions remain optimistic about the potential for internal rotation and catch-up gains.

Among the various components of humanoid robots, one crucial element found throughout the body is the reducer. This sector's index has surged by nearly 60% since the beginning of the year.

Precision reducers play a pivotal role in humanoid robots, serving as essential components that connect servo motors and actuators. They primarily function to reduce speed and increase torque, enabling precise adjustment of the robot's rotation angle. With their high precision, stability, and strong load-bearing capacity, precision reducers are particularly well-suited for robot joints.

The precision reducers used in humanoid robots are mainly categorized into harmonic reducers and RV reducers.

Harmonic reducers achieve speed reduction through the meshing of waveform teeth between a flexible wheel (elastic deformation element) and a rigid wheel. As the flexible wheel deforms, its teeth engage with those of the rigid wheel, thereby transmitting torque. Characterized by their simplicity and high precision, harmonic reducers, however, have relatively lower load-bearing capacity and transmission efficiency.

On the other hand, an RV reducer is a type of planetary gear reducer that achieves speed reduction through a planetary gear system. The planetary gears rotate around the sun gear and are constrained by the internal gear ring, resulting in efficient speed reduction. While RV reducers have a more complex structure and higher precision requirements, they boast strong load-bearing capacity.

In practical applications, harmonic reducers and RV reducers are deployed in different parts of humanoid robots. Due to their flexibility, harmonic reducers are more apt for use in hand joints, leg joints, and other parts of humanoid robots. Conversely, RV reducers, with their robust load-bearing capacity, are more suitable for the torso of robots.

An Orient Securities research report highlights the rapid progress of Tesla's humanoid robot, which has achieved significant iterations in less than two years. This includes the completion of a development platform, the debut of the Optimus product, and the realization of various capabilities such as motor torque control, environmental detection and memory, and the execution of complex tasks with both hands. Considering the potential market performance of Tesla's humanoid robot, the report estimates its market impact under different production scenarios. When Tesla's humanoid robot production reaches 500,000, 1 million, and 2 million units, the global reducer market space may expand by 6 billion yuan, 11.2 billion yuan, and 21 billion yuan, respectively.

For investors' reference, Securities Star has compiled a list of some reducer concept stocks. Please note that this list does not constitute investment advice.

1. Leadshine Technology: Specializing in the R&D, design, production, and sales of precision transmission devices, the company's product line includes harmonic reducers, precision components, and mechatronic actuators. It holds a strong market position in harmonic reducers, with a global market share second only to Harmonic Drive.

2. Double Ring Gears: Successfully developed industrial robot RV reducers and is now researching harmonic reducers to cater to robots with varying loads. In China, its RV reducer market share ranks second only to Nabtesco, the global leader in RV reducers.

3. Fengli Intelligence: Active in the harmonic reducer field. According to public information, Fengli Intelligence's harmonic reducer production capacity is projected to reach 140,000 units annually in the future, with production scale gradually expanding based on market demand.

4. Zhongda Lide: Engaged in the R&D, manufacturing, and sales of motor drives, micro-special motors, precision reducers, and other products. Its product line covers core components for industrial robots, including RV reducers and harmonic reducers. Among domestic RV reducer manufacturers, it ranks second only to Double Ring Gears and plays a significant role in the domestic substitution of RV reducers.

5. Fengguang Precision: Actively involved in the harmonic reducer field. Recently, the company announced plans to raise funds for a production project with an annual output of 300,000 harmonic reducers and the construction of a research and development center. Fengguang Precision has certain advantages in harmonic reducer research and production, possesses mass production capabilities, and its product parameters can be compared to industry leader Harmonic Drive to some extent.

6. Xiangyang Bearing: Primarily engaged in the production of bearings and their components, auto parts, electromechanical equipment, bearing equipment, and spare parts. Cone bearings, ball bearings, and other products for reducers are the company's main offerings.

7. Greatoo Intelligence: The company's reducers are characterized by high precision, low noise, smooth operation, compact structure, high strength, reliable performance, and long service life, making them a viable alternative to imported products.

8. RDI Technology: The company's subsidiaries, including Chongqing RDI Transmission Machinery Co., Ltd., Chongqing RDI Transmission Co., Ltd., Chongqing Dihan Power Machinery Co., Ltd., and Ma'anshan RDI Transmission Machinery Co., Ltd., are the main operating platforms for its transmission business. Currently, the company's reducer-related products are already in use.

9. Jiangsu Leili: The company's controlled subsidiary, Dingzhi Technology, has deployed precision gearbox reducers for coreless motors, suitable for use in robot joints.

10. Fuda Co., Ltd.: The company has established a dedicated technical team to develop key robot component products and has achieved significant results in robot reducer products by leveraging its existing precision gear production capacity.