Humanoid Robot Motors vs Maxon & Kollmorgen: China's Frameless & Coreless Drive

Why motors are the most repeated BOM line

A humanoid repeats the same motor architecture dozens of times. Two frameless torque motors per leg, per arm; roughly 20 coreless motors inside a single dexterous hand, times two hands. The cost may be "only" ~12% of BOM, but performance here sets the robot's whole ceiling: torque density decides how heavy it can carry, cogging torque decides how smooth it pours tea, and dynamic response decides whether it can recover from a stumble. That is why this is the most contested component after reducers.

Two motor families, two battles

The incumbents: Maxon and Kollmorgen

Maxon (Switzerland) is the coreless-motor benchmark: self-supporting hollow-cup rotors eliminate cogging, deliver ~90% efficiency, millisecond response, and have flown in Mars rovers and surgical robots. At Hannover Messe 2026 it showed its HEJ (High Efficiency Joint) series — integrated joint modules from the HEJ 70 (62 N·m) and HEJ 90 (140 N·m) to a "Hercules" variant above 250 N·m, IP67-sealed, EtherCAT CiA 402. Kollmorgen (US) leads frameless direct drive with its TBM series, designed to embed straight into a joint and minimize inertia. These are the motors Chinese engineers design against — and increasingly, design around on price.

The Chinese challengers, by order book

• Moons' Electric (鸣志电器, SSE) — China's #1 coreless maker and top-3 globally, already in Tesla's supply chain. It runs a full "motor + driver + transmission + closed-loop" platform, ships coreless motors into dexterous hands and upper-arm joints, and held roughly RMB 4.2B in orders as it expanded lines. The open risk: Gen-3 humanoid redesigns may substitute some of its content.
• Kinco (步科股份) — the frameless-torque challenger. Q1 2026 frameless unit sales grew +246% YoY with batch orders from leading Chinese humanoid customers, and it held roughly RMB 3.3B in orders with lines at full load.
• Dingzhi (鼎智科技, BJSE) — 6–14 mm coreless, frameless and voice-coil motors, an AgiBot partner (see Dingzhi profile).
• Leisai 雷赛智能, Huichuan 汇川, Haozhi 昊志, ZhaoWei 兆威 — the rest of the deep bench across frameless, servo and miniature gearmotor lines.

The honest comparison

The gap is now best described as "performance close, price decisive." Chinese frameless and coreless motors meet humanoid-grade specs at a fraction of the cost, and — critically — they iterate with Chinese humanoid makers on monthly cycles rather than annual Western sales cycles. Maxon and Kollmorgen retain the highest-precision, regulated niches (surgery, aerospace, Mars); Moons' and Kinco are winning the volume market that actually builds robots by the thousand.

Frequently asked questions

What motors does a humanoid robot use?

Two families: frameless torque motors (rotor + stator only, no housing) for large hip/shoulder/knee joints, and coreless (hollow-cup) motors for dexterous hands and small joints. A single dexterous hand needs about 20 coreless motors.

Who makes the best humanoid robot motors?

Maxon (Switzerland) is the historical benchmark for coreless motors, and Kollmorgen (US) for frameless torque motors via its TBM series. Chinese makers Moons' Electric (coreless, #1 in China, top-3 globally) and Kinco (frameless torque, Q1 2026 unit sales +246%) are the fast challengers.

How much do motors cost in a humanoid robot?

Motors are roughly 12% of a humanoid's hardware BOM — second only to actuators/reducers. Chinese motors typically cost 50–70% of Maxon/Kollmorgen equivalents while reaching a large share of performance.

Can Chinese motors replace Maxon or Kollmorgen?

For volume humanoid programs, increasingly yes. Moons' supplies coreless motors globally (including Tesla's supply chain) and holds ~RMB 4.2B in orders; Kinco holds ~RMB 3.3B in frameless orders. Western leaders still hold the extreme-precision, aerospace and deep-space niches.