The core principle of a rotary actuator is based on harmonic drive technology, which transmits motion through the engagement of a flexible spline and a rigid spline.
Its structure typically consists of three main components: a wave generator, a flex spline, and a circular spline. The wave generator drives the flex spline to deform elastically, engaging periodically with the circular spline. This converts high-speed, low-torque input into low-speed, high-torque output.
This design reduces mechanical backlash and improves transmission accuracy. In addition, optimized materials and heat treatment processes extend the service life of key components.

A Harmonic Rotary Actuator is a highly integrated precision motion control unit that combines a harmonic drive reducer, frameless torque motor, absolute encoder, and optional electromagnetic brake into a compact assembly.
Unlike conventional servo systems that require separate motors, gearboxes, and couplings, an Integrated Harmonic Actuator provides a complete rotary motion solution with high positioning accuracy, zero backlash, and a significantly simplified mechanical design.
HONPINE offers both standard Harmonic Drive Rotary Actuators and Large Hollow Harmonic Rotary Actuators for demanding industrial automation applications.

In industrial robotics, rotary actuators must meet requirements for high load capacity and high repeat positioning accuracy. For example, in six-axis robotic arms, their compact structure saves installation space, while low-friction design reduces energy consumption and supports long-term continuous operation.
In precision machining equipment, micron-level transmission accuracy helps ensure high surface quality of processed workpieces.
In addition, some models integrate sealed structures to improve dust and water resistance, making them suitable for environments with strict cleanliness requirements such as automotive manufacturing and food processing.

A Large Hollow Harmonic Rotary Actuator features an oversized through-hole that allows cables, pneumatic tubes, fiber optics, laser beams, and other utilities to pass directly through the actuator center.

Compared with traditional solid-shaft rotary actuators, the large hollow structure offers several benefits:

Cleaner and more organized cable routing
Reduced installation space
Improved machine appearance
Less cable bending and wear
Lower risk of signal interference
Easier integration into compact equipment

This design is especially suitable for collaborative robots, semiconductor equipment, laser processing systems, and precision automation.

The energy-saving advantages of rotary actuators mainly come from two aspects:
First, improved transmission efficiency reduces energy loss—for example, by using low-friction coatings or optimized lubrication systems to reduce mechanical friction.
Second, lightweight design reduces overall weight, thereby lowering the load requirements on the driving motor.

A HONPINE Integrated Harmonic Actuator typically includes:

High-precision harmonic drive reducer
Frameless torque servo motor
Multi-turn absolute encoder
Optional electromagnetic brake
Integrated bearing system
Compact housing and sealing structure

This integrated design minimizes assembly errors while improving overall system rigidity and reliability.

HONPINE Harmonic Gear Actuators provide several key advantages:

Zero backlash transmission
High positioning accuracy
Large hollow shaft design
Compact integrated structure
High torsional rigidity
Maintenance-free operation
IP65 protection as standard (IP67 optional)
Easy installation
Long service life exceeding 15,000 operating hours under rated load

Through proprietary optimization algorithms, HONPINE also significantly improves overall actuator rigidity compared with conventional harmonic drive systems.

Under rated operating conditions, the positioning accuracy of a HONPINE Harmonic Drive Rotary Actuator can be maintained for more than 15,000 hours.

The actuator features a sealed, maintenance-free design that eliminates the need for periodic lubrication replacement, reducing overall maintenance costs throughout its lifetime.

Harmonic rotary actuators offer stable performance with a precision retention life of more than 15,000 hours.
With a direct-drive integrated design and a fully sealed structure, installation is simple and truly plug-and-play.
For applications with limited space, heavy loads, and high precision requirements, harmonic mechatronic actuators provide an ideal solution.

Harmonic servo actuators are widely used in:
Machine tool rotary tables
Laser cutting systems
Electronics and semiconductor equipment
Precision CNC machine tools
3C (computer, communication, consumer electronics) equipment
Precision laser processing equipment
LED manufacturing equipment
Inspection and testing equipment
Medical devices
Robots and special robotic arms
Printing machinery and inkjet equipment
Glass processing equipment
Precision measuring instruments

The actuator combines high overturning rigidity, high torque load capacity, and smooth operation, featuring zero backlash and low noise.
With a service life exceeding 15,000 hours, it is maintenance-free and does not require lubricant replacement.
The hollow shaft design allows easy routing of cables and pneumatic lines. It is compatible with standard servo drives and supports plug-and-play installation.

HONPINE Rotary Joint Actuators are widely used in industries requiring high precision, compact installation, and flexible cable routing, including:

Semiconductor equipment
Wafer handling systems
Precision CNC rotary tables
Laser cutting and laser marking machines
Electronic assembly equipment
Medical devices
Surgical robots
Collaborative robots (Cobots)
Industrial robot joints
Inspection and metrology equipment
Printing machinery
Glass processing equipment
Automation production lines

Operating life: 15,000 hours
Operating temperature: −20 °C to +75 °C

The harmonic rotary actuator is equipped with a 23-bit encoder compliant with the Tamagawa protocol.
The motor is designed to work with a 48 V servo drive. Customers may use their own Tamagawa-compatible encoders, or HONPINE can provide an external drive for added convenience.

HONPINE operates two comprehensive test benches rated at 0–100 N·m and 100–1000 N·m, covering the full size range from 11 to 58.
High-precision power analyzers accurately measure current, torque, efficiency, and other parameters, automatically generating performance curves and torque-speed (T-n) curves.
This ensures all specifications are verified by actual output performance, not theoretical estimates. Additional equipment is used for accuracy and rigidity testing.

To address common industry challenges, HONPINE has introduced the upgraded HAT-G series rotary actuator.
While conventional models may deform and rebound under load, the HAT-G series uses advanced proprietary control algorithms to achieve over three times higher rigidity. Under identical loading conditions, dial indicator deflection is almost negligible.
An optional high-precision encoder is available, enabling positioning accuracy of ≤5 arc-seconds.

HONPINE uses high-precision power analyzers to accurately measure current, torque, efficiency, and other key parameters, automatically generating data curves and torque-speed (T-n) curves.
All performance data is validated through real output testing, supported by additional accuracy and rigidity measurement equipment, ensuring reliable and truthful specifications.

HONPINE Servo Rotary Actuators support mainstream industrial communication protocols, including:

EtherCAT
CANopen

Standard encoder options include:

Multi-turn absolute encoder
Tamagawa 23-bit protocol
Nikon 24-bit protocol

These encoder options provide high-resolution position and speed feedback for precise motion control.

HONPINE Harmonic Rotary Actuators feature a flange-mounted integrated design for quick installation.

For optimal performance:

Ensure proper shaft alignment
Follow recommended mounting torque specifications
Route cables through the hollow shaft whenever possible
Use compatible servo drives based on motor specifications

The integrated design significantly reduces installation time compared with conventional motor-gearbox assemblies.

No.

HONPINE Integrated Harmonic Actuators are designed for maintenance-free operation.

Under normal operating conditions, users do not need to:

Replace grease
Perform periodic internal maintenance
Disassemble the actuator

Routine inspection is recommended to monitor vibration, operating temperature, and abnormal noise for preventive maintenance.

Standard operating conditions include:

Operating temperature: 0–40°C
Storage temperature: –20–60°C
Relative humidity: 20–80% RH (non-condensing)
Vibration resistance: 24.5 m/s² (10–400 Hz)
Protection rating: IP65 standard
Optional protection: IP67

The actuator is intended for indoor industrial environments free from corrosive gases, excessive dust, oil mist, and explosive atmospheres.

Yes.

As a professional Harmonic Actuator Manufacturer, HONPINE offers extensive customization services, including:

Custom flange dimensions
Mounting hole configurations
Hollow shaft sizes
Brake options
IP67 waterproof protection
Connector types
Cable outlet directions
Mechanical interface modifications

Our engineering team works closely with customers to optimize actuator integration for specific applications.

The actuator and servo drive are installed separately.

Servo drives should be selected according to the actuator's motor specifications, including:

Rated voltage
Rated current
Torque constant
Encoder type
Communication protocol

HONPINE provides professional drive selection support to ensure optimal system performance.

HONPINE provides comprehensive technical resources for every Harmonic Rotary Actuator, including:

Product catalogs
Selection guides
Dimensional drawings
3D CAD models
Electrical documentation
Performance data
Technical consultation before and after purchase

Please contact the HONPINE sales team to request the complete documentation package.

HONPINE uses high-precision power analyzers to accurately measure current, torque, efficiency, and other key parameters, automatically generating data curves and torque-speed (T-n) curves.
All performance data is validated through real output testing, supported by additional accuracy and rigidity measurement equipment, ensuring reliable and truthful specifications.

HONPINE operates two comprehensive test benches rated at 0–100 N·m and 100–1000 N·m, covering the full size range from 11 to 58.
High-precision power analyzers accurately measure current, torque, efficiency, and other parameters, automatically generating performance curves and torque-speed (T-n) curves.
This ensures all specifications are verified by actual output performance, not theoretical estimates. Additional equipment is used for accuracy and rigidity testing.

Simply put, the precision of a reducer refers to the deviation between the actual output position and the theoretical position after the motor’s rotation is transmitted through the gearbox.

For example, if the motor inputs 180°, and the reduction ratio is 10:1, the theoretical output should be 18°. However, in reality, the gearbox rarely stops exactly at 18°. If it stops at 18.02°, then the 0.02° difference is the positioning error. Converting this into a smaller unit, 0.02° equals 1.2 arcminutes. This is what we refer to as gearbox positioning accuracy error.

The harmonic rotary actuator is equipped with a 23-bit encoder compliant with the Tamagawa protocol.
The motor is designed to work with a 48 V servo drive. Customers may use their own Tamagawa-compatible encoders, or HONPINE can provide an external drive for added convenience.

This is because any mechanical transmission involves clearances, friction, and elastic deformation between components. These are the main “culprits” that cause positioning errors.

It is worth noting that many gearboxes on the market claiming “zero backlash” are often misleading. “Zero backlash” does not mean “zero positioning error.” Backlash is only one factor affecting accuracy. Even if gear-to-gear backlash is eliminated, components such as bearings and couplings still have clearances, and achieving true zero backlash between gears is extremely difficult.

Therefore, when purchasing a gearbox, it is important to confirm its actual positioning accuracy.

The performance parameters of HONPINE harmonic rotary actuators are based on real test data, whereas many reducers and actuators on the market publish specifications that often differ from actual performance.

Torsional rigidity refers to the amount of deformation at the output shaft under a unit load, reflecting the actuator’s resistance to deformation.
Under balanced loading conditions, torsional rigidity has little effect on positioning accuracy. However, under eccentric or unbalanced loads, it has a significant impact.
For example, consider a 170 mm rotary table used in a machine tool, vertically mounted. If a 20 kg eccentric load is applied with a 100 mm offset from the rotation center, then when positioning at 90°, this load generates a torque on the output shaft of:
20 × 9.8 × 0.1 ≈ 20 N·m
In machine tool rotary tables and tilting heads, higher torsional rigidity allows for machining harder materials and larger cutting volumes, significantly improving the performance and efficiency of multi-axis machine tools. This is critical for machine tool applications.
Ranking of torsional rigidity (from low to high)
Harmonic < RV < SPINEA cycloidal = roller cam < Sumitomo cycloidal < PSC b