Electromate Introduces maxon HEJ 70 High-Efficiency Joint for Mobile Robotics

The HEJ 70 48 50 actuator combines a torque-dense motor, planetary gearbox, 14-bit absolute encoder, and EtherCAT control electronics into a sealed, IP67-rated package. It delivers a peak torque of ±50 Nm and a maximum joint speed of 28 rad/s, with efficiencies up to 74% at 12 Nm and 26 rad/s.

Toronto, Canada - August 8, 2025 - Electromate Inc., Canada's exclusive distributor of maxon precision mechatronic components, announces the release of the HEJ 70 High-Efficiency Joint actuator. This compact, fully integrated robotic joint actuator is engineered to meet the demanding performance needs of mobile and manipulation robots.


Product Overview
The HEJ 70 48 50 actuator combines a torque-dense motor, planetary gearbox, 14-bit absolute encoder, and EtherCAT control electronics into a sealed, IP67-rated package. It delivers a peak torque of ±50 Nm and a maximum joint speed of 28 rad/s, with efficiencies up to 74% at 12 Nm and 26 rad/s. The actuator's compact design (1.05 kg) and high performance make it suitable for lightweight robotic applications.

Key Specifications
• Peak Torque: ±50 Nm (future variants may exceed 60 Nm)
• Max Joint Speed: 28 rad/s @ 60 V; 22 rad/s @ 48 V
• Efficiency: Up to 74% at 12 Nm and 26 rad/s
• Ingress Protection: IP67 (sealed against dust and water)
• Voltage Range: 30-60 V DC
• Control Interface: EtherCAT (daisy-chain), PWM fan control, 1 kHz cycle rate, PDO-mapped gains
• Position Sensor: 14-bit absolute encoder, < 0.6° error
• Torque Sensing: Current-based, ± 0.8 Nm accuracy
• Backdrive Torque: ~0.5 Nm
• Output Bearing: Cross-roller bearing

Performance & Reliability
• Continuous Torque: ±19 Nm at 2 rad/s without extra cooling
• Efficiency Peak: ~74% at 12 Nm & 26 rad/s; generator efficiency reaches ~72%
• Designed for High Cycle Fatigue: 12 million impacts at 38 Nm, 100k at 50 Nm
• Operating Life Examples: Over 56,000 hours at 10 Nm, 22 rad/s

Use Cases
The HEJ 70 actuator is ideal for:
• Autonomous mobile manipulators and cobots
• Lightweight robotic arms and grippers
• Quadruped and biped robots
• End-effector joints, compact SCARA joints, and wearable robotics

Integration Highlights
• Ready-to-use with onboard control electronics, torque & position sensing, and active cooling system
• Simplified system architecture using EtherCAT daisy-chain; reduces external cabling
• Includes simulation models for design verification and sizing

Availability
The HEJ 70 High-Efficiency Joint actuator is available for quote in Canada through Electromate Inc. For more information or to request a quote, visit https://www.electromate.com/hej-70-high-efficiency-joint-for-mobile-robots/

About Electromate Inc.
Electromate Inc. is a Canadian-owned and operated company specializing in precision robotic and mechatronic components and systems. As the exclusive Canadian distributor of maxon products, Electromate provides high-quality solutions for a wide range of applications, including robotics, automation, and industrial equipment.

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