Guotai Junan Securities: Agile hand structure towards high bearing development, the number of screws may double

According to the financial news app Zhitong Finance, Guojin Securities released a research report stating that the dexterous hand is a core component of robots. The changes in Tesla's (TSLA.US) third-generation dexterous hand compared to the second generation are as follows: the hand has increased its degrees of freedom from 11 to 22, and the number of motors may increase from the original 6 to 13-17; the driver mounting position has been changed from the hand to the wrist. In terms of driving, motor drive is currently the mainstream driving method for dexterous hands. With the increased degrees of freedom in the third generation dexterous hand, the required number of motors will increase, benefiting suppliers of hollow cup motors and brushless slotted motors. In terms of transmission, the tendon rope + worm gear and worm screw was Tesla's first-generation solution. With the gradual maturity of the industry in dexterous hand lead screws, coupled with Tesla's need to increase the single-handed load capacity, using lead screws for transmission in the hand may be a development direction, benefiting the lead screw industry supply chain.

Based on functionality and long-term goals, the trend of dexterous hands moving towards human hands is inevitable. If expressed as a function, the conditions for robotic dexterous hands replacing human hands are F(X,Y,Z) = (degrees of freedom, grasping ability, perception ability, load-bearing capacity, stability, economy) ≥ F(human hands).

Degrees of freedom are where the most significant changes occur in Tesla's dexterous hand. According to Tesla's official video for GEN2, the single-handed degrees of freedom for GEN2 are 11, while at the Tesla 24Q2 performance meeting, Musk mentioned that the subsequent hand degrees of freedom will be 22, moving closer to human hands. This means that the number of single-degree-of-freedom components, such as drive devices, transmission devices, and sensing devices, will all increase accordingly.

In terms of drive devices, it is expected that hollow cup motors and brushless slotted motors will become mainstream. Assuming a quantity of about 13-17 for a single hand, the current value for both hands is 34,000-153,000 yuan. Drive methods include motor drive, hydraulic drive, pneumatic drive, and shape memory alloy drive. Due to advantages such as small size and fast response, motor drive has become the mainstream solution with strong cost-effectiveness. Taking Tesla as an example, its hand uses hollow cup motors. According to the Maxon official website, the unit price is 4675 yuan, while the hollow cup motors at the Zhaowei Electromechanical flagship store are about 2000 yuan each, and the brushless slotted motors are priced at only 160 yuan each. Based on cost considerations, brushless slotted motors are expected to partially replace hollow cup motors due to their higher cost-effectiveness. In the mid-to-high-end sector, the hollow cup motor market is mostly dominated by foreign manufacturers, with foreign companies holding a market share of over 85%. However, there are many domestic enterprises involved in the industrial use of hollow cup motors, which are expected to quickly enter the field of robotics and achieve localization to reduce costs.

In terms of transmission devices, it is currently a critical time for the transition from tendon ropes to lead screws. Assuming a quantity of 13-17 sets for a single hand, the current value for both hands is 55,000-130,000 yuan. Transmission methods mainly include tendon ropes, lead screws, gears, connecting rods, etc. Early dexterous hands used gear and connecting rod transmission mechanisms, but they were gradually eliminated due to problems such as large size and weight, and limited flexibility in movement. Tendon rope transmission, imitating the way animal tendons work, is currently widely used in dexterous hands. However, the issue with this solution is its relatively low load-bearing capacity, which may be replaced by lead screw solutions with higher load-bearing capacity. At the 2024 Beijing Robotics Exhibition, KGG exhibited 4mm diameter planetary roller screws and 1.5mm diameter planetary ball screws;In addition, KGG also exhibited a dexterous hand integrated with a planetary roller screw solution. Currently, there are few companies that have laid out the hand micro screw market, including Xinjian Transmission, Wuzhou Xinchun, and KGG.

Regarding sensor devices, tactile sensors are the most valuable component, with about 5 sets for a single hand and a total value of about 1351 yuan for both hands. According to the Tesla GEN2 conference, Tesla robots are confirmed to be equipped with tactile sensors. Other sensors in dexterous hands include joint torque sensors, joint absolute position sensors, motor Hall sensors, and temperature sensors. The top three global tactile sensor manufacturers are Tekscan, Pressure Profile Systems, and Sensor Products Inc, with a combined market share of 65%. In China, companies such as Moxian Technology, Suzhou Nengsida, Paxini, and Ligank Technology have already entered the tactile sensor market, and it is expected that the domestic substitution rate will increase due to cost advantages.

Dexterous hands are evolving towards higher degrees of freedom, high perceptual capabilities, and lower costs. Currently, the cost of a single high-performance dexterous hand is about 45,000 to 130,000 yuan, with the high-performance dexterous hand DLR priced at 800,000 yuan each, offering significant room for cost reduction. The price of a single hand in mass production is expected to be below 10,000 yuan. The combined cost of hollow cup motors and roller screws accounts for over 90% of the total cost, making it the core area for cost reduction. Currently, the technology of dexterous hands in the United States is superior to that in China, with many foreign companies achieving over 20 degrees of freedom. The Chinese dexterous hand with the most degrees of freedom is Qinglong (19 degrees). With active domestic investment and price advantages, Chinese dexterous hands are expected to capture more market share.

Investment Advice

Dexterous hands are a core component of robots. According to publicly available information from Tesla, the changes in Tesla's third-generation dexterous hand compared to the second generation are: (1) the hand has increased its degrees of freedom from 11 to 22, which may increase the number of motors from the original 6 to 13-17; (2) the location of the driver has been changed from the hand to the wrist. In terms of driving, motor drive is the current mainstream method for dexterous hand drive. With the increase in degrees of freedom in the third generation, the required number of motors will increase, benefiting hollow cup motor and brushless slotted motor suppliers. In terms of transmission, tendon + worm gear was Tesla's first-generation solution. As the industry's dexterous hand screw technology matures, coupled with Tesla's need to increase single-hand load capacity, using screws for hand transmission may be a development direction. If a single hand requires 13 screws, then a humanoid robot would need 26 screws, benefiting the screw industry supply chain. In terms of sensing, the first generation used Hall sensors, and the second generation added tactile sensors. Due to the significant value of tactile sensors, this is favorable for related sensor companies.

Risk Warning

Risks include slower-than-expected progress in robot implementation, underperformance in the existing downstream business, intensified competition, and risks of prices falling more than expected