Product Description
This joint module is equipped with a 100:1 high-precision reduction ratio, providing large torque output and precise positioning. It integrates a brushless motor and a high-efficiency harmonic reducer, has high rigidity, low backlash, and long life, and is suitable for high-precision, high-load scenarios such as industrial robots and automation equipment, and supports modular rapid integration.

Port Definition | Port Description |
①EtherCAT_OUT | EtherCAT output |
②EtherCAT_In | EtherCAT input |
③CAN_H | CAN_H network signal terminal |
④CAN_L | CAN_L network signal terminal |
⑤GND | Power supply negative pole |
⑥VCC | Power supply positive pole |
⑦BAT- | Multi-turn battery negative pole |
⑧BAT+ | Multi-turn battery positive pole |
⑨RES- | Discharge resistor port |
⑩RES+ | Discharge resistor port |
⑪ T+ | Master sends control command to module |
⑫ T- | Module sends status feedback to master |
⑬ R+ | Master reflects module status data |
⑭ R- | Module reflects master control command |
Exploded View
The compact size integrated of this product includes FOC control board high-precision multi-turn absolute encoder, frameless torque motor, precision harmonic reducer and other main components.

1. Motor back cover
2. Contol board
3. Encoder
4. Stator casing
5. Motor rotor
6. Motor stator
7. Harmonic drive
8. Flex spline cover
Harmonic integrated articulated crossed roller bearing

The rollers are arranged crosswise at 90°,
which enables them to withstand radial force, axial force and overturning moment,
and have the characteristics of high precision, high stability, high load capacity and high rigidity.
Built-in Dual Absolute Value Encoder

Built-in dual absolute value encoders, full closed-loop control
The input and output terminals adopt 17-bit
absolute value encoders, with a repeat positioning
accuracy of less than 0.01 degrees.
It can remember the power-off positions
of single and multiple turns.
It features full closed-loop control, compensates
for transmission errors, and ensures high accuracy without wear.
Communication

Optional EtherCAT, CANopen, communication protocols.
Position,Speed, Current loop PID adjustable in real-time.
Product parameters
Parameters | Unit | EHD - 14 | EHD-17 | EHD-20 | EHD-25 | RH-32 |
Gear ratio | - | 100 | 100 | 100 | 100 | 100 |
Input Voltage | V | 48 | 48 | 48 | 48 | 48 |
No Load Speed | RPM | 30 | 30 | 30 | 30 | 20 |
No Load Current | A | 0.9 | 145 | 2.59 | 1.61 | 3.9 |
Rated Speed | RPM | 25 | 25 | 25 | 25 | 18 |
Rated Torque | N.m | 11 | 35 | 50 | 108 | 150 |
Rated Power | W | 100 | 180 | 250 | 400 | 700 |
Rated Current | A | 6.5 | 9 | 13 | 16 | 20 |
Peak Torque | N.m | 28 | 54 | 80 | 157 | 229 |
Peak Current | A | 16.25 | 13.86 | 20.8 | 23.2 | 33.44 |
Back - EMF Constant | Vdc/kgm | 1.39 | 2.79 | 2.79 | 4.89 | 6.28 |
Torque Constant | N.m/A | 0.02 | 0.04 | 0.04 | 0.07 | 0.09 |
Phase Resistance | Ω | 0.62 | 0.7 | 0.36 | 0.155 | 0.08 |
Phase Inductance | mH | 0.43 | 0.47 | 0.51 | 0.33 | 0.18 |
Pole Pair | - | 10 | 10 | 10 | 10 | 10 |
3 Phase Connection | - | Y | Y | Y | Y | Y |
Backlash | Arcsec | - | <20 | <20 | <20 | <20 |
Encoder Type&Interface | - | Dual encoder/ABS - 17bit | Dualencoder/ABS-17bit | Dualencoder/ABS-17bit | Dualencoder/ABS-17bit | Dualencoder/ABS-17bit |
Repeat Position Accuracy | Degree | <0.01 | <0.01 | <0.01 | <0.01 | <0.01 |
Communication | - | CAN / EtherCAT | CAN /EtherCAT | CAN /EtherCAT | CAN/ EtherCAT | CAN /EtherCAT |
Insulation grade | - | F | F | F | F | F |
Stall torque data | ||||
EHD-20 | Torque | Temperature rise | Stalling time | Phase current |
(N.m) | (℃) | (s) | (Arms) | |
75 | 12 | 15 | 10.5 | |
100 | 8 | 10 | 13.5 | |
125 | 15 | 8 | 18 |
*1. Standard motors only support non-brake.
*2. Standard motors support CAN bus and EtherCAT.
*3. Standard motors do not have waterproof function. If you need IP54, please contact sales before ordering.
*4. This product also supports 50:1 reduction ratio. Please contact sales to confirm delivery time before ordering.
*5. Rated torque test method: Under ambient temperature of 24 degrees Celsius (no other heat dissipation method), the motor torque reaches temperature balance under the condition of 60 degrees temperature rise and can work for a long time. The rated torque value of the motor.
Dimensions
Application
The joint module is a high-performance mechatronic drive unit that integrates a high-torque brushless motor, a precision reducer, and an intelligent control system. It is suitable for robot joints, automation equipment, industrial robotic arms, and other scenarios. Its 50N·m rated torque and 13A current output can meet medium and high load requirements, while also having high precision, low noise, and long life. The modular design supports rapid installation and maintenance, and is widely used in collaborative robots, medical equipment, logistics sorting, and intelligent manufacturing, significantly improving the dynamic response and energy efficiency of the equipment.





Service
1. Does it support waterproof and dustproof? What is the protection level?
Yes, our joint modules can be customized with waterproof and dustproof functions according to customer needs.
The standard version is not waterproof for indoor applications, and can be equipped with IP54 protection, which is suitable for certain outdoor
or humid environments. If you have higher protection requirements (such as IP67), you can contact us for customization.
2. Does it support customized reduction ratio?
Yes. We can provide customized solutions with different reduction ratios according to your application requirements.
The conventional reduction ratio range covers: 10:1 ~ 200:1, and the best combination can be matched according to load, speed, and torque requirements.
3. What is the difference between the single encoder and dual encoder versions?
The single encoder version monitors the rotation of the motor end and is suitable for general precision requirements;
the dual encoder version monitors the motor end and the output end at the same time, which can effectively compensate
for the backlash and elastic error, and is suitable for high-precision control and high safety requirements (such as collaborative robots, medical equipment).
4. What communication interfaces can the joint module support?
The standard version supports analog control (current/voltage command) or pulse command control;
According to the needs, it can be optionally equipped with support for industrial bus protocols
such as CANopen, EtherCAT, Modbus-RTU, etc. (customization is required).
5. Does it support integrated drive and control? Can it be directly connected to the controller?
We provide optional integrated drive and control joint modules with built-in motor drivers and position servo controllers.
Users can directly control through the bus or pulse interface without external independent drivers, simplifying wiring and system integration.
6. Are there standard 3D model files available for download?
Yes. We provide 3D model files in STEP format for all models, which facilitates customers to quickly integrate mechanical design.
If you need to obtain it, please contact our sales staff to obtain the download link or data package.
7. What is the operating temperature range?
The standard operating temperature range is: -10°C ~ +50°C.
If you need to resist low or high temperature applications (such as cold storage, hot working environment),
you can customize special temperature control solutions.
8. Can the joint module be designed hollow? Can it be wired?
Some models are designed with hollow shafts, and the center aperture can be used for wiring, air pipes, water pipes, etc.,
which is convenient for realizing the functional layout of complex end effector.
For specific center aperture sizes, please refer to the model selection table or consult customer service.
9. How long is the standard delivery period and customized delivery period?
Standard model delivery period: usually 7-14 working days.
The delivery period for customized requirements (such as, reduction ratio customization, communication protocol customization, etc.)
depends on specific requirements, generally 5-10 weeks.
10. How long is the warranty period? How about after-sales service?
All joint module products provide a 12-month warranty period (under normal use).
We provide remote technical support, fault diagnosis guidance, and fast spare parts supply services.
Paid repair and maintenance services are also available outside the warranty period.
Packing list
A. Power cable *2
B. CAN bus communication cable *2/Bleeding resistor cable *1/Multi-turn battery cable *1
C. 120Ω terminal resistor *1
D. EtherCAT communication cable *2