Harmonic Drive Systems

Founded: 1970
HQ: Tokyo
Website: www.hds.co.jp/en/ ↗

Harmonic Drive Systems manufactures strain-wave (harmonic) reducers, actuators, and AC servo motors that are the dominant choice for small, lightweight robot joints such as wrists, forearms, and hands. The company held roughly 85% of the global harmonic-reducer market in 2023.

Strain-wave gearing — the technology Harmonic Drive Systems has refined for over five decades — delivers exceptional torque density, zero backlash, and compact form factors that make it uniquely suited to the dexterous joints of humanoid robots. The company's reducers are found across industrial, collaborative, and service robots worldwide, and the strain-wave architecture has been adopted in next-generation humanoid platforms including Tesla Optimus, though Tesla has not publicly disclosed its specific supplier. Alongside reducers, Harmonic Drive Systems offers integrated actuator modules and servo systems that simplify the mechanical design of robot limbs. Its long manufacturing heritage and near-monopoly scale give it unmatched process quality and supply reliability for robotics customers globally.

Sources