#Planetary reducers (3)

The Complete Robot Joint Module Selection Guide: Harmonic, Planetary, RV, Cycloidal & Quasi-Direct Drive — Vendor Research and Configurations by Robot Weight Class

How should robot joint modules actually be selected? Drawing on 200+ joint-module/reducer entries in the RobotWorld knowledge base, product research on leading vendors (Harmonic Drive, Nabtesco, Leaderdrive, Laifual, Leadshine, EYOBOT, ZeroErr, JIECANG, CubeMars, ENCOS), and item-by-item verification of the supply chains behind Tesla, Unitree, UBTECH, AgiBot and Fourier, this guide systematically compares harmonic, planetary, RV, cycloidal and quasi-direct-drive (QDD) transmission routes on performance and cost, provides a torque-tier product cheat-sheet (0.5-200 N·m) and full configuration recipes by robot weight class (small <=25kg / mid 30-55kg / large 60-100kg), plus a practical pitfall-avoidance playbook.

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Joint modulesHarmonic reducersPlanetary reducersQuasi-direct driveHumanoid robots

PJ Series Planetary Joint Module for Humanoid Robots

PJ series planetary joint modules for humanoid locomotion joints: optimized reducer for high output and low noise. Example model: ratio 18, 90 N·m start/stop peak torque, 142 rpm rated, 10 arcsec backlash, 17-bit encoder, CAN bus, 105 mm OD with 50 mm through-hole, 0.83 kg.

COMPONENT

Joint modulesPlanetary reducersHumanoidLeadshine

Haydon Kerk Pittman PLG42S Planetary Gearbox (4:1-512:1)

Haydon Kerk Pittman (AMETEK, USA) PLG42S is a 42 mm planetary gearbox covering ratios 4:1-512:1 in 1-3 stages: max load 3.5-14 Nm (496-1,983 oz-in), stage efficiency 90%/81%/73%, weight 270-880 g and length 47.6-71.2 mm with CW output; pairable with DC040B and other motors as gearmotors for robot joints, medical devices and precision automation.

COMPONENT

Planetary reducersPlanetary GearboxHKPPrecision transmission42mm