Integrated robot joint actuator
HEBI Robotics R-Series integrated robot joint actuator
IP67 sealed version of HEBI's smart actuators (R8 and R25) for outdoor and wash-down use, up to 40 Nm continuous and 80 Nm peak with ±4-turn absolute sensing and fibre-optic Ethernet.
Key specifications
| Voltage (max) | 48 V |
|---|---|
| Ingress protection | IP67 |
| Temperature | -10–50 °C |
| Data / bus | 100 Mbps Ethernet over plastic optical fibre (OptoLock), 2 ports |
| Rated torque (max) | 40 Nm |
| Peak torque (max) | 80 Nm |
| Speed (max) | 118 rpm |
| Supply | 24–48 VDC |
| Feedback | multi-turn absolute position ±4 turns, 0.005° resolution, ±0.2° accuracy; IMU; internal pressure sensor |
| Weight | 670 g |
| Mass (max) | 1.9 kg |
| Models | R8-3+, R8-9+, R8-16+, R25-8, R25-20, R25-40 |
Summarised in our own words from HEBI Robotics's published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2
Notes on this data
weight_g is the lightest model (R8-3+). Gear ratio not stated.
Specify Motion is not affiliated with HEBI Robotics. HEBI Robotics and R-Series are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a HEBI Robotics part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Hollow-shaft harmonic servo actuator: strain-wave gearing, motor, encoder and brake in one unit, run from a separate servo drive. Six frame sizes, from 48 VDC to 220 VAC.
| Published maximum | R-Series | MAH |
|---|---|---|
| Peak torque | 80 Nm | 800 Nm meets or exceeds |
| Rated torque | 40 Nm | 557 Nm meets or exceeds |
| Speed | 118 rpm | 125 rpm meets or exceeds |
High-rigidity Wanshsin inline planetary with three backlash classes down to super-precision, for machine tools, automation and AGVs.
| Published maximum | R-Series | WSH |
|---|---|---|
| Peak torque | 80 Nm | 7,200 Nm meets or exceeds |
| Rated torque | 40 Nm | 2,400 Nm meets or exceeds |
| Speed | 118 rpm | 6,000 rpm meets or exceeds |
Right-angle version of the high-rigidity WSH, with a spiral bevel stage and ratios up to 200:1.
| Published maximum | R-Series | WSHR |
|---|---|---|
| Peak torque | 80 Nm | 4,200 Nm meets or exceeds |
| Rated torque | 40 Nm | 1,400 Nm meets or exceeds |
| Speed | 118 rpm | 6,000 rpm meets or exceeds |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What an integrated robot joint actuator is
An integrated robot joint actuator packages a brushless motor, a reduction gear, encoders, a servo drive and often a brake or torque sensor into one module that bolts in as a robot joint. Gearing may be planetary, strain-wave or cycloidal. Many are designed for legged robots, humanoids and cobots, with low gear ratios or quasi-direct drive to keep the joint back-drivable and responsive. Communication is typically over CAN or EtherCAT, with position, velocity and torque control modes.
When engineers choose an integrated robot joint actuator
Choose an integrated joint actuator to build robots faster with fewer parts, especially legged, humanoid, exoskeleton and collaborative robots. Back-drivable versions suit force control and impacts. The trade-offs are torque density, precision and industrial qualification: low-ratio designs trade output torque for transparency, and some units are aimed at research rather than production duty. For industrial arms with heavy duty cycles, a dedicated harmonic actuator or motor and gear set may be better.
How to specify the HEBI Robotics R-Series
Send these with your enquiry and an engineer can confirm the right R-Series variant or an equivalent:
- Peak and continuous output torque (Nm)
- Output speed (rpm)
- Gear type and ratio
- Back-drivability and torque sensing
- Supply voltage (V DC)
- Communication interface and control modes
- Mass and size (kg, mm)
Common mistakes to avoid
- Using peak torque as continuous torque
- Ignoring thermal limits in legged robots
- Overlooking bus bandwidth with many joints
- Assuming research-grade units meet industrial life requirements
HEBI Robotics R-Series: frequently asked questions
What is the HEBI Robotics R-Series?
IP67 sealed version of HEBI's smart actuators (R8 and R25) for outdoor and wash-down use, up to 40 Nm continuous and 80 Nm peak with ±4-turn absolute sensing and fibre-optic Ethernet. Published series figures include voltage 48 V, temperature -10 °C, temperature 50 °C, rated torque 40 Nm. It is made by HEBI Robotics; Specify Motion can help source it or propose an equivalent.
Who makes the HEBI Robotics R-Series?
The HEBI Robotics R-Series is made by HEBI Robotics and is listed here for engineers comparing options. Specify Motion is not affiliated with HEBI Robotics; brand names are used only to identify the product.
What is the voltage of the HEBI Robotics R-Series?
The published series maximum voltage is 48 V. Individual models and sizes in the R-Series range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the HEBI Robotics R-Series?
Yes. On published figures, MAH and Wanshsin WSH are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What is a quasi-direct-drive actuator?
A quasi-direct-drive actuator uses a high-torque motor with a low gear ratio, typically below about 10:1, so the joint is back-drivable and responds quickly to external forces. This suits legged robots and force control. The trade-off is lower output torque than high-ratio joints of similar size.
Why integrate the drive in a robot joint actuator?
Integrating the drive reduces cabling and lets each joint communicate over a shared bus, which simplifies robot design. It also allows the drive to sit close to the motor, improving control. The trade-off is that heat from both motor and drive must be managed inside the joint.
Further reading: How to select a harmonic actuator · Frameless motor sizing robot joints · Gearboxes and harmonic drives
Other integrated robot joint actuator series
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