Electric servo-actuator 25

electromechanicalrotaryservo-motor

Introduction
The large hollow bore rotary actuator integrates a frameless internal-rotor torque motor with a harmonic drive reducer, absolute encoder and a customized large hollow-bore harmonic drive unit to form a complete rotary actuator assembly. The drive/control unit is typically mounted externally, enabling high-precision motion control for connected equipment. This series provides an increased hollow-bore diameter to accommodate lead screws, cable routing and other through-shaft requirements, making it suitable for machine tool rotary tables, precision medical devices, 5-axis laser cutting systems and semiconductor equipment.

Structural Characteristics

• Modular architecture combining high-resolution encoders and intelligent power modules (IPM) for compact integration and strong EMI immunity.
• Supports multiple control modes (position/speed/torque) and is compatible with AC permanent-magnet synchronous motors and DC servo motors.

Control Algorithm

• Vector-based triple-loop control (current/speed/position) to optimize dynamic response accuracy and stability.
• Advanced control logic executed on digital signal processors (DSP) with support for network communication and remote debugging.

Performance Highlights

• Micron-level positioning: high-resolution encoder feedback reduces cumulative error and achieves sub-micron repeatability.
• Fast dynamic response: low electromechanical time constant enables millisecond-level starts/stops and direction reversals for high-frequency motion.
• Wide speed range: supports high-torque low-speed and light-load high-speed operation with speed ratios exceeding 1:5000.

Adaptability

• Compatible with standard interfaces (EtherCAT, CANopen) for straightforward PLC/system integration.
• Integrated soft-start circuitry and overvoltage/overcurrent protection reduce startup surges and failure risks.

Features

• High-efficiency control: torque-dense design and regenerative braking achieve >90% energy efficiency.
• Superior dynamics: full-digital control enables <1ms response times for complex motion profiles.
• Safety redundancy: dual closed-loop verification (encoder + sensor) and on-board fault diagnostics for reliable operation.
• Environmental resilience: high-temperature components and dust-resistant coatings rated for operation from -20°C to 70°C.

Product Parameters (AC-220V)
Model groups: 25, 32, 40 (each group supports reduction ratios 51, 81, 101, 121, 161)
Reduction ratios: 51 | 81 | 101 | 121 | 161 (per model group)
Rated torque (N·m) — Model 25: 68.5 | 107 | 133 | 133 | 133; Model 32: 133 | 206 | 264 | 267 | 267; Model 40: 242 | 351 | 460 | 557 | 557
Peak torque (N·m) — Model 25: 121 | 169 | 194 | 207 | 217; Model 32: 267 | 376 | 411 | 436 | 459; Model 40: 497 | 641 | 702 | 762 | 800
Rated speed (RPM) — Model 25: 49 | 31 | 25 | 21 | 16; Model 32: 45 | 28 | 23 | 19 | 14; Model 40: 39 | 25 | 20 | 17 | 12
Max speed (RPM) — Model 25: 94 | 59 | 48 | 40 | 30; Model 32: 90 | 57 | 49 | 38 | 29; Model 40: 80 | 51 | 41 | 34 | 25
Rated current (A) — Model 25: 3.90 | 3.84 | 3.83 | 3.20 | 2.40; Model 32: 5.82 | 5.68 | 5.83 | 4.93 | 3.70; Model 40: 8.72 | 7.97 | 8.37 | 8.46 | 6.36
Max current (A) — Model 25: 6.90 | 6.07 | 5.58 | 4.97 | 3.92; Model 32: 11.69 | 10.36 | 9.08 | 8.04 | 6.36; Model 40: 17.91 | 14.55 | 12.75 | 11.58 | 9.13
Torque constant (N·m/Arms) — Model 25: 17.54 | 27.86 | 34.74 | 41.62 | 55.38; Model 32: 22.85 | 36.29 | 45.25 | 54.21 | 72.13; Model 40: 27.74 | 44.06 | 54.94 | 65.82 | 87.58
Unidirectional positioning accuracy (arcsec) — Model 25: ≤60 | ≤50 | ≤50 | ≤40 | ≤40; Model 32: ≤60 | ≤50 | ≤50 | ≤40 | ≤40; Model 40: ≤60 | ≤50 | ≤50 | ≤40 | ≤40
Repeat positioning accuracy (arcsec) — ≤10 (all variants)
Tilt stiffness (×10^4 N·m/rad) — Model 25: 38; Model 32: 95; Model 40: 175
Torsional stiffness (×10^4 N·m/rad) — varies by ratio and model (see parameter rows above)
Motor phase resistance (Ω, 20°C) — examples per group: 3.55 | 0.88 | 0.8
Motor phase inductance (mH) — examples per group: 10 | 6.1 | 8
Back-EMF constant (Vrms/Krpm) — 40 | 40 | 44
Rotor inertia without brake (kg·m²) — 2.1×10^-4 | 8.3×10^-4 | 1.64×10^-3
Rotor inertia with brake (kg·m²) — 2.2×10^-4 | 1.04×10^-3 | 2.05×10^-3
Mass (without brake, kg) — Model 25: 3.6 | Model 32: 7.4 | Model 40: 10.7
Motor poles — 16 (listed groups)
Dimensions (diameter × length, mm, examples with/without brake): ø116 × 109 mm; ø126 × 109 mm; ø142 × 138.7 mm; ø170 × 150.7 mm
Hollow shaft diameter (mm) — ø26 | ø35 | ø45

Technical specifications

• Product type: Large hollow-bore harmonic drive rotary actuator (frameless motor + harmonic drive + encoder assembly).
• Typical applications: machine tool rotary tables, precision medical devices, 5-axis laser cutting, semiconductor equipment.
• Supported model groups: 25, 32, 40; each group supports reduction ratios 51, 81, 101, 121, 161.
• Repeat positioning accuracy: ≤10 arcsec across listed variants; unidirectional accuracy down to ≤40 arcsec on higher-precision variants.
• Rated torque range: approximately 68.5 N·m up to 557 N·m depending on model and reduction ratio.
• Peak torque range: approximately 121 N·m up to 800 N·m.
• Hollow shaft diameters available: ø26 mm, ø35 mm, ø45 mm.
• Operating temperature resilience: designed for operation from -20°C to 70°C.