Compact Planetary Joint Motor Actuator for Robot Dog

The Standard Planetary Joint Motor is a core component of robotic power systems. Through a highly integrated design combining a planetary reducer, frameless torque motor, brake, encoder, and driver, it achieves significant optimization in volume and weight, enabling precise motion control of the joint. This results in greater torque, smaller size, and lighter weight. Compared to harmonic joint modules, the planetary joint module features a smaller reduction ratio, higher output speed, and greater torque density, making it more suitable for medium-to-low load applications. We also provide customization services tailored to clients’ specific requirements.

Components

• Power Unit: Frameless torque motor: Provides a compact power source, suitable for high dynamic response requirements.
• Two-stage planetary reducer: Optimizes space through a nested gear structure, improves torque transmission efficiency.
• Sensing and Control: Dual absolute encoders (motor end + output end): Supports complete closed-loop control, improves positioning accuracy.
• Friction brake: Ensures emergency stop safety and zero-speed starting stability.
• Communication Module: Supports CAN bus protocol, compatible with multi-axis coordinated control.

Features

• High Torque Density and Power Performance: Multi-stage planetary reduction structure: Through multi-stage gear combination, torque density can reach above 20N·m/kg, suitable for high-load driving requirements of robotic hip joints, legs, and other parts.
• Peak torque output: Delivers greater peak torque output, meeting instantaneous power demands in dynamic motion scenarios.
• Impact Resistance and High Reliability: Advantages of planetary gear transmission: Gear meshing disperses impact force, enabling the transmission to withstand harsh working conditions such as emergency stops and high-frequency load changes, making it suitable for high-dynamic scenarios like bipedal robot walking and jumping.
• Mass production controllability: The planetary reducer solution features mature technology, ensuring high consistency and reliability in mass production, making it suitable for large-scale applications.

Compact Structure and Lightweight Design

• High integration: The nested design of the planetary reducer, frameless motor, encoder, and other components reduces volume by 30% compared to traditional solutions.
• Lightweight materials: Utilizing high-strength alloys and a compact layout, these materials meet the stringent requirements of humanoid robots for lightweight and high energy efficiency.

High Precision and Low Energy Consumption

• Low cogging torque and dual encoder closed-loop: Reduces torque ripple, combined with dual absolute encoders (motor end + output end), achieves ±0.05° repeat positioning accuracy.
• Transmission efficiency optimization: Planetary reducer transmission efficiency reaches above 80%.
• Multi-axis Coordinated Control: Supports CAN bus protocol to meet multi-degree-of-freedom coordinated motion requirements of robots.

Economy and Maintenance Convenience

• Maintenance-free design: Stable planetary reducer structure requires no regular lubrication, reducing long-term use costs.
• Modular interfaces: Standardized design facilitates quick replacement and upgrades, shortening robot development cycles.