Planetary roller screws
Convert motor rotation into high-force linear motion for linear actuators in legs and arms.
Data updated
Why it matters
Planetary (and inverted planetary) roller screws carry much higher loads than ball screws in a compact package. Tesla's Optimus reportedly uses 14-16 of them in linear actuators for knees, hips, elbows and wrists.
Why it is a bottleneck. Grinding high-precision threads is slow and specialized. Swiss makers GSA and Rollvis are reported to hold more than half of global supply, and Chinese challengers are investing billions of yuan to make screws at about half the price.
Cost. One humanoid-grade planetary roller screw is estimated at $1,350-2,700 (J.P. Morgan, 2025, not specific to Rollvis); Optimus Gen 2 carries 14.
Suppliers 6
- GSA / RollvisPlanetary and inverted planetary roller screws
- HIWIN TechnologiesBall screws, harmonic reducers, crossed-roller bearings, joint modules; planetary roller screws (planned)
- Schaeffler (incl. Ewellix)Integrated rotary actuators (60-250 N·m: planetary gearbox, motor, encoder, controller); planetary roller screws; bearings
- Shanghai Beite TechnologyPlanetary roller screws, ball screws, micro screws
- Wuzhou XinchunInverted planetary roller screws; bearings
- Xinjian TransmissionPlanetary roller screws