Planetary roller screw: By using threaded rollers instead of balls, the number of contact points is increased, thereby enhancing load capacity, rigidity and service life. It is suitable for high-performance demand scenarios, such as humanoid robot joints.
1) The application of planetary roller screws in humanoid robots
In humanoid robot, joints are the core components to realize motion and action control, which are divided into rotary joints and linear joints:
--Rotating joints: Mainly include frameless torque motors, harmonic reducers and torque sensors, etc.
--Linear joint: By using planetary roller screws in combination with frameless torque motors or stepper motors and other components, it provides high-precision transmission support for linear motion.
The Tesla humanoid robot Optimus, for example, uses 14 planetary roller screws (provided by GSA, Switzerland) for its linear joints to cover the core components of the upper arm, lower arm, thigh, and lower leg. These high-performance roller screws ensure the high precision and reliability of the robot during motion execution. Although the current cost is relatively high, there is considerable room for cost reduction in the future.
1) The market pattern of planetary roller screws
Global market:
The market concentration of planetary roller screws is relatively high, mainly dominated by several internationally leading enterprises:
Swiss GSA: The global market leader, together with Rollvis, holds over 50% of the market share.
Swiss Rollvis: The second largest in the global market, acquired by GSA in 2016.
Ewellix of Sweden: Ranked third in the global market, it was acquired by the German Schaeffler Group in 2022.
Domestic market:
The import dependence of domestic planetary roller screw is about 80%, and the total market share of head manufacturers GSA, Rollvis, Ewellix and so on is more than 70%.
However, the potential for domestic substitution is gradually emerging. Currently, some domestic enterprises have already achieved mass production capabilities, while many others are in the verification and trial production stages.
Currently, miniature inverted planetary roller screws are also a core strength of KGG.
KGG develops precision roller screws for humanoid robot dexterous hands and actuators.
Post time: Jun-10-2025
