Product · February 2026

Inside the KH harmonic actuator

How we got to 369 Nm peak torque out of a 2.75 kg frame.

A KH actuator is a finished joint: frameless BLDC motor, harmonic reducer, 15-bit multiturn encoder and FOC driver in one housing. Bolt it to the link, run one CAN-FD cable, and the current loop is already closed inside the unit.

KH-25 is the heavy end of the range — 38 to 140 Nm rated, 369 Nm peak, about 2.75 kg. KH-14 sits at the wrist. KH-17 and KH-20 cover the mid-arm joints most cobot and humanoid designs actually need.

Voltage is 24–48 V DC so it runs on the supply already on the machine. Gear ratios are 30, 50 or 100 : 1, or a ratio specified for the load case. Daisy-chaining cuts the loom down the arm to a single cable.