Large Hollow Bore Harmonic Drive Rotary Actuator

●  Introduction

The large hollow bore rotary actuator typically integrates an internal rotor frameless torque motor with components such as a harmonic drive reducer, absolute encoder, and customized large hollow bore harmonic drive unit to form a complete rotary actuator assembly. Its control unit (drive system) is usually externally mounted, enabling high-precision motion control for connected equipment. Compared to standard rotary actuators, this series features a larger hollow bore diameter, allowing passage of lead screws, cables, and other components. It is designed for applications requiring large through-bore space, high precision, and compact integration, such as machine tool rotary tables, precision medical devices, 5-axis laser cutting systems, and semiconductor equipment.
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Features 

● Structural Characteristics
  • Modular design integrating high-precision encoders and intelligent power modules (IPM), offering compact size and strong EMI resistance.

  • Supports multiple control modes (position/speed/torque) and is compatible with both AC permanent magnet synchronous motors and DC servo motors.


●  Control Algorithm

  • Vector-based triple-loop control (current/speed/position) optimizes dynamic response accuracy and stability.

  • Implements complex control logic via digital signal processors (DSPs), supporting networked communication and remote debugging.


●  Performance Highlights

  • Micron-level positioning: High-resolution encoder feedback eliminates cumulative errors, achieving sub-micron repeatability.

  • Rapid response: Low electromechanical time constant enables millisecond-level start/stop or direction reversal, ideal for high-frequency motion.

  • Wide speed range: Supports low-speed high-torque and high-speed light-load operation, with a speed ratio exceeding 1:5000.


●  Adaptability

  • Compatible with standard interfaces (e.g., EtherCAT, CANopen) for seamless PLC/system integration.

  • Built-in soft-start circuits and overvoltage/overcurrent protection reduce startup surges and failure risks.

Advantages

● High-efficiency control

Torque-dense design and regenerative braking achieve >90% energy efficiency.


● Superior dynamic performance

Full digital control enables <1ms response times for complex motion planning.


● Safety redundancy

Dual closed-loop verification (encoder + sensor) and fault self-diagnostics ensure reliability.


● Environmental resilience

High-temperature components and dust-resistant coatings support operation from -20°C to 70°C.

Specification

Sheet 1

Product Parameters(AC-220V)
Model
253240
Reduction Ratio/518110112116151811011211615181101121161
Rated TorqueN·M68.5107133133133133206264267267242351460557557
Peak TorqueN·M121169194207217267376411436459497641702762800
Rated SpeedRPM493125211645282319143925201712
Max SpeedRPM945948403090574938298051413425
Rated CurrentA3.903.843.833.202.405.825.685.834.933.78.727.978.378.466.36
Max CurrentA6.906.075.584.973.9211.6910.369.088.046.3617.9114.5512.7511.589.13
Torque ConstantN·M/Arms17.5427.8634.7441.6255.3822.8536.2945.2554.2172.1327.7444.0654.9465.8287.58
Unidirectional Positioning AccuracyArcsec
≤60≤50≤50≤40≤40≤60≤50≤50≤40≤40≤60≤50≤50≤40≤40
Repeat Positioning AccuracyArcsec≤10≤10≤10≤10≤10≤10≤10≤10≤10≤10≤10≤10≤10≤10≤10
Tilt StiffnessX104N.m/rad3895175
Torsional StiffnessX104N.m/rad3.44.67.69.91418.6
Motor Phase ResistanceOhma(20°C)3.550.880.8
Motor Phase InductanceMh106.18
Back-EMF ConstantVrms/Krpm404044
Rotor InertiaWithout BrakeKG*m22.1*10^-48.3*10^-41.64*10^-3
Rotor InertiaWith BrakeKG*m22.2*10^-41.04*10^-32.05*10^-3
Mass(Without Brake)Kg3.67.410.7
Motor PolesPole161616
Diameter & Length (With/Without Brake)mmø116mmX109mm
ø126mmX109mm
ø142mmX138.7mmø170mmX150.7mm
Hollow Shaft Diametermmø26mmø35mmø45mm
NotesFor reference only, please contact sales for actual parameters