Electromate Introduces the maxon HEJ Series in Canada: Compact, High Torque Robot Joints for Robotic Applications
August 11, 2025
New HEJ Series: Designed for the Demanding Performance Needs of Mobile & Manipulation Robots
Electromate, Canada’s exclusive distributor of precision mechatronic components from maxon, is now offering the new High-Efficiency Joint (HEJ) series—a compact, integrated actuator solution developed to meet the demanding performance needs of mobile and manipulation robots.
The HEJ 90 and HEJ 70 units combine maxon’s core competencies—brushless motors, gearboxes, encoders, and motion controllers—into sealed joint actuators ready for harsh, real-world applications.
The HEJ actuators are engineered for use in legged robots (including quadrupeds and bipeds), autonomous mobile manipulators, compact robotic arms, and wearable systems such as exoskeletons. Each unit features integrated joint control electronics with 1 kHz loop cycles, sensor feedback, and active thermal management. Built-in heat sinks and high-load output bearings (cross-roller type) enhance reliability for outdoor, dynamic, or mobile use cases.
With onboard control, torque sensing, and EtherCAT daisy-chaining capabilities, the HEJ series reduces the number of external components and cables required, enabling system integrators to speed up development and simplify system complexity.
Features
HEJ90
- Delivers up to 140 Nm peak torque (180 Nm optional)
- Max joint speed: 13 rad/s
HEJ70
- Delivers 50 Nm peak torque
- Max joint speed: 28 rad/s
Key Benefits
- High output powers, well-coolable
- Dynamic motions and high peak torques
- Efficiencies up to 86%
- IP67 ingress protected
- Integrated electronics and joint output bearing
- Ideal for Mobile Autonomous Robots: Humanoids, Quadrupeds, and Mobile Manipulators
Specifications
HEJ 90
The HEJ 90 is maxon’s high‑torque, fully integrated joint actuator designed for mobile and locomotion robotics. It combines motor, gearbox, encoder, controller, and thermal management in a compact, sealed package rated for IP67 environments. With peak torque up to 140 Nm (customizable to 180 Nm) and smooth EtherCAT control, it’s ideal for rugged outdoor or field applications.
Key Specifications
| Parameter | HEJ 90‑48‑140 |
|---|---|
| Peak Torque | 140 Nm (up to 180 Nm custom) |
| Max Joint Speed | 13 rad/s |
| Dimensions (Ø × L) | 110 mm × 90 mm |
| Mass | 1.96 kg |
| Efficiency | Up to 86 % |
| Ingress Protection | IP67 (sealed under bending loads) |
| Voltage Range | 30–60 V DC |
| Control Interface | Dual EtherCAT, 1 kHz control, torque/velocity/position/impedance modes |
| Position Encoder | Absolute, integrated |
| Output Bearing | Cross-roller bearing |
Performance & Reliability
- Designed for high-torque robotic joints in mobile or field robotics
- Sealed IP67 housing allows operation in wet or dirty environments
- High-efficiency design minimizes battery drain on mobile platforms
- Cross-roller output bearing supports large axial and radial loads
- Optional active cooling enables extended duty cycles under load
- Internal thermal monitoring and fan control protect against overheating
- Control loop runs at 1 kHz, supporting real-time torque, velocity, and position control
Use Cases
The HEJ 90 is suited for a wide range of robotic systems, including:
- Legged robots with heavy payload requirements (quadrupeds, humanoids)
- Autonomous mobile manipulators
- Hip, knee, and base joints in walking robots
- Propulsion joints for field-deployed tracked or wheeled robots
- Outdoor robotics requiring sealed, rugged actuator modules
Integration Highlights
- All-in-one actuator simplifies system architecture—no external drives or sensors needed
- Dual EtherCAT ports support daisy-chaining in multi-joint setups
- Position feedback via absolute encoder with integrated torque estimation
- Simulation models and documentation available for sizing and control development
- Low backlash and minimal backdrive torque support stable force control
- Electromate offers full support from selection to deployment
For more information on the HEJ 90 HERE
HEJ 70
The HEJ 70 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
| Parameter | HEJ 70‑48‑50 |
|---|---|
| Peak Torque | ± 50 Nm (future variants may exceed 60 Nm) |
| Max Joint Speed | 28 rad/s @ 60 V | 22 rad/s @ 48 V |
| Mass | 1.05 kg |
| Efficiency | Up to 74% (measured at 12 Nm, 26 rad/s) |
| Ingress Protection | IP67 (sealed against dust and water) |
| Voltage Range | 30–60 V DC |
| Control Interfaces | 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 |
| Average Backlash |
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 h at 10 Nm, 22 rad/s
Use Cases
- 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
For more information on the HEJ 70 HERE
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