Selecting the Right Actuator for Cobot and Legged Robot Joints

High-torque robotic gear motors integrate a precision brushless motor with a compact planetary or cycloidal gearbox into a single sealed unit, delivering the output torque and positional accuracy required for robot joints, collaborative robot (cobot) arms, legged robot actuators, and industrial pick-and-place end effectors. Jiangsu Retek Motion Co., Ltd. produces a dedicated robotic gear motor series claiming 20% more output torque than comparable market alternatives, available in torque ranges from 10 N·m to over 150 N·m within a compact form factor that simplifies mechanical integration.

Related Products

LN3115 900KV FPV Brushless Motor 6s 8~10 Inch Propeller Long Range Drone

LN3115 900KV FPV Brushless Motor 6s 8~10 Inch Propeller Long Range Drone

View Details
Brushless DC Motor for Electric Power Tools 28mm Diameter W28 Series

Brushless DC Motor for Electric Power Tools 28mm Diameter W28 Series

View Details
Brushless DC Motor for Steering System 30mm Diameter w30 Series

Brushless DC Motor for Steering System 30mm Diameter w30 Series

View Details
BL76 76mm Diameter Brushless DC Motor

BL76 76mm Diameter Brushless DC Motor

View Details
Nema 14 Stepper Motor 3D Printer CNc High Torque 1.8 Deg Standard Step ST35 Stepping Motor

Nema 14 Stepper Motor 3D Printer CNc High Torque 1.8 Deg Standard Step ST35 Stepping Motor

View Details
LN1505 1800KV 2200KV 2600KV Brushless Motor for RC Drone FPV

LN1505 1800KV 2200KV 2600KV Brushless Motor for RC Drone FPV

View Details

Introduction

Detailed Parameters and Performance Data

RETEK: High-Torque Robotic Gear Motors Delivering 20% More Output in the Same Footprint

Jiangsu Retek Motion Co., Ltd. provides robotic gear motor actuators for collaborative robot manufacturers, legged robot developers, and industrial automation integrators where torque density, positional accuracy, and communication bus compatibility are the decisive specification criteria. We achieve 20% higher output torque in the same bolt-circle envelope through a proprietary stator geometry and N50H magnet grade selection, validated against competing catalog units on a calibrated dynamometer. Our standard actuators ship with multi-turn absolute encoders and CAN bus interfaces pre-wired, eliminating the integration work typically required to combine a commercial motor, encoder, and drive board. Hollow-shaft output variants are available for joint designs that route cable looms through the actuator center, a common requirement in contemporary cobot wrist and elbow designs.

Applications

Advanced Technology Highlights

Applications

  • 6-DOF collaborative robot arm joints (shoulder, elbow, wrist actuators)
  • Legged robot hip, knee, and ankle drives for bipedal and quadruped platforms
  • Industrial pick-and-place robot end-effector wrist drives
  • Autonomous mobile robot (AMR) steering and traction modules
  • Exoskeleton and rehabilitation robot joint actuators
  • Camera pan-tilt-zoom (PTZ) broadcast and security heads

Technical Specifications

Industrial & Commercial Usage

Specifications

FeatureDetails
Output Torque Range10 N·m – 150+ N·m
Gear TypePlanetary / cycloidal (application dependent)
Backlash<1 arcmin (precision series); <3 arcmin (standard)
Gear Ratio Options10:1 – 200:1
Input Voltage24 V / 48 V DC
FeedbackMulti-turn absolute encoder standard; resolver optional
CommunicationCAN bus, RS-485, EtherCAT on request
HousingAluminum alloy 6061-T6
IP RatingIP54 standard; IP67 available
Torque Density vs. Market+20% output torque in same envelope

Additional Information

Supplementary Details & Notes

Production and Customization Services

Retek Motion supports robotic actuator OEM programs from prototype through series production, with engineering collaboration available at each development stage.

  • Gear Ratio Customization: Intermediate ratios between 10:1 and 200:1 available for programs requiring specific output speed or torque not achievable with standard ratios; tooling cost amortized over 50-unit minimum.
  • Hollow-Shaft Output: Bore diameter machined to drawing; cable routing clearance and rotary seal options specified at design stage.
  • EtherCAT Firmware Option: CiA 402 motion control profile firmware available for EtherCAT master integration; provided with XML device description (ESI) file for EtherCAT configurator import.
  • IP67 Sealing: Full submersion-rated seal package (shaft seal, O-ring housing, potted connector) available for outdoor robot platforms and washdown-duty industrial cobots.
  • Backlash Measurement Report: Each precision-series actuator individually measured for backlash at output shaft; report included with shipment for robot calibration records.
  • Compliance Testing: EMC pre-compliance testing and CE declaration support provided for robotics OEM product certification submissions.

Service & Support

Advantages

  • +20% Torque Density: Proprietary stator geometry and high-energy magnet selection yield measurably higher output torque per kilogram than competing catalog units in the same bolt-circle.
  • Sub-Arcminute Backlash: Precision planet carrier and ground ring gear minimize positional dead-band — critical for cobot arms in force-controlled assembly tasks.
  • Integrated Absolute Encoder: Multi-turn absolute position data eliminates homing routines after power cycling — a major time saver in automated production lines.
  • Sealed IP54 Housing: Protects internal gear train from metal swarf and coolant mist in machining-adjacent robot installations.
  • CAN Bus Ready: Native CAN bus reduces wiring complexity in multi-joint robot architectures using a single daisy-chained cable harness.

Frequently Asked Questions

  • Q: How does your robotic gear motor compare to Maxon or Harmonic Drive units?
  • A: Retek Motion gear motors offer competitive torque density and backlash specifications at a lower price point, well-suited for cost-sensitive cobot platforms and pilot production runs. For ultra-low-backlash requirements, Retek Motion can also supply a matched cycloidal reducer as an alternative.
  • Q: Is EtherCAT available as a standard interface?
  • A: EtherCAT is an available option for OEM orders of 20 units or more. The onboard driver firmware supports CiA 402 motion control profile for plug-and-play integration with Beckhoff and Omron EtherCAT masters.
  • Q: Can the output shaft be customized for hollow-shaft wiring passthrough?
  • A: Yes. Hollow-shaft output versions are available for robot joint designs that route cables or pneumatic lines through the actuator center. Specify bore diameter at inquiry stage.

Resources

Advanced Material Selection Guide

Robotic actuator material selection must balance torque density, fatigue life under dynamic loading, and backlash stability over the service life of the robot.

  • Gear Material — Case-Hardened 20CrMnTi vs. 17CrNiMo6: 20CrMnTi is the standard planet and ring gear material for most robotic actuator applications, providing good core toughness and case hardness (58–62 HRC). 17CrNiMo6 (case hardness to 62 HRC, higher core impact toughness) is specified for legged robot joints subject to high impact loads during gait transitions and falls.
  • Housing Material — 6061-T6 vs. 7075-T6 Aluminum: 6061-T6 is adequate for cobot arm joints operating within collaborative force limits. 7075-T6 is specified for legged robot hip joints where crash-impact structural loads may exceed the yield strength of 6061-T6.
  • Encoder Type — Incremental vs. Multi-Turn Absolute: Multi-turn absolute encoders eliminate homing cycles and retain position knowledge through power cycles — essential for collaborative robots operating in shared human-robot workspaces where uncontrolled motion after power restoration is a safety concern.
  • Bearing Type — Angular Contact vs. Cross-Roller: Cross-roller bearings (high combined axial/radial/moment load capacity) are preferred for the output stage of cobot wrist joints where overhanging tool loads generate significant moment forces on the output flange. Angular contact pairs are used for higher-speed intermediate stages.
  • Gear Lubricant — Synthetic PAO vs. Mineral Oil Grease: Synthetic polyalphaolefin (PAO) grease maintains consistent viscosity across a wide temperature range (-40 °C to +130 °C), preferred for outdoor mobile robot platforms. Mineral oil grease is adequate for controlled indoor factory environments.

About Jiangsu Retek Motion Co., Ltd.

Unlike other motor suppliers, Retek engineering system prevents the selling of our motors and components by catalogue as every model is customized for our customers. The customers are assured that every component they receive from Retek is designed with their exact specifications in mind. Our total solutions are a combination of our innovation and a close working partnership with our customers and suppliers.

As China Robotic Gear Motors – High Torque Manufacturers and Wholesale Robotic Gear Motors – High Torque OEM/ODM Suppliers, Retek business consists of three platforms: Motors, Die-Casting and CNC manufacturing and wire harness. Retek products are widely supplied for residential fans, vents, boats, airplanes, medical facilities, laboratory facilities, trucks and other automotive machines.

Welcome to send us an RFQ, it is believed you will get the best cost-effective products and services here!
Customized Solutions
Quality Assurance
Global Export
Jiangsu Retek Motion Co., Ltd.
<

Recommended LINS

High Torque Brushless DC Motors High Torque Stepper Motor Gearbox Right Angle Bevel Gear High Torque Nema 17 Stepper Gearbox Planetary Dc Planetary Geared Motor 62mm 78mm High Torque High KV FPV Drone Motors High Torque Nema 23 Stepper Motor 8-Wire Bi-Polar/Uni-Polar Frameless Torque Motors for Robotics High Power Brushless DC Motors
Message Feedback