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Kollmorgen AKM22E-ACC2R-0
Product Introduction:
The AKM22E-ACC2R-0 is the smallest motor in Kollmorgen’s AKM product family, designed for ultra-compact motion applications requiring precise positioning in minimal space. The “22” denotes the 22mm frame size, “E” indicates the motor length variant, “ACC” specifies a multi-turn absolute encoder, “2” is the 2500 RPM speed rating, “R” denotes the winding code, and “0” indicates a smooth (keyless) shaft with set-screw locking.
Detailed content
Model Designation Breakdown:
- AKM = AKM Series
- 22 = Frame Size 22mm
- E = Length Variant E (medium length in 22mm family)
- ACC = Multi-Turn Absolute Encoder
- 2 = Speed Rating: 2500 RPM
- R = Winding Code R
- 0 = Smooth Shaft, Set-Screw Locking (no keyway)
Technical Specifications:
| Parameter | Value |
|---|---|
| Frame Size | 22 mm |
| Continuous Torque | 0.22 Nm |
| Peak Torque | 0.66 Nm (3× rated, 10s) |
| Rated Speed | 2500 RPM |
| Rated Power | 55 W (0.074 HP) |
| Supply Voltage | 48 VDC (nominal), 36–60 VDC range |
| Motor Type | Brushless DC (BLDC), Sinusoidal |
| Cooling Method | Convection (self-ventilated) |
| Encoder Type | Multi-Turn Absolute, BiSS-C / Hiperface |
| Encoder Resolution | 128 lines (512 counts/rev) |
| Holding Brake | No |
| Shaft Type | Smooth (Ø4mm), Set-Screw Locking |
| Protection Class | IP54 (with connector) |
| Insulation Class | Class F (155°C) |
| Weight (approx.) | 0.12 kg |
Material Composition:
- Stator Core: High-grade silicon steel (0.2mm laminations)
- Stator Windings: Fine copper wire (0.15mm), Class F insulation
- Rotor: NdFeB magnets (130°C rated, small diameter)
- Housing: Aluminum alloy (micro-die-cast)
- Shaft: Stainless steel 303, ground (Ra < 0.2μm), Ø4mm smooth
- Bearings: Miniature ball bearings (MR series, sealed)
Structural Features:
- Ultra-compact 22mm diameter — fits in finger-joint spaces
- Smooth shaft with set screw — clamp-style mounting (no keyway)
- Rear-mounted encoder — M8 or M12 connector
- 2× mounting holes — M2.5 on 20mm bolt circle
- Total length: ~45mm (including encoder)
Working Principle:
The AKM22E is a miniature three-phase BLDC motor. The servo drive supplies sinusoidal three-phase currents to the stator, creating a rotating magnetic field that drives the NdFeB rotor. The multi-turn absolute encoder (BiSS-C protocol) provides position feedback. The smooth shaft with set screw transmits torque via friction clamping — the set screw presses against a flat on the shaft, locking it to the coupling hub.
Key Advantages:
- Smallest AKM motor — 22mm diameter, 55W, 0.22 Nm
- Multi-turn absolute encoder — position known immediately on power-up
- 48V DC — safe, low-voltage operation
- Smooth shaft — zero backlash with set-screw clamp
- Ultra-lightweight — 120 grams
Applicable Industries:
- Surgical Robot Joints
- Drone Gimbal Motors
- Micro-Positioning Stages
- Camera Pan/Tilt Units
- Wearable Robotics (exoskeletons)
- Smart Valve Actuators
Installation Requirements:
- Mount with 2× M2.5 bolts on 20mm bolt circle
- Set screw torque: 0.5 Nm (do not over-tighten — shaft damage)
- Coupling: Miniature flexible coupling, bore Ø4mm
- Encoder cable: M8/M12 shielded, max 3m (short runs recommended)
- Ambient: -10°C to +40°C (no derating in this range)
Usage Precautions:
- Set screw must be tightened every 500 hours — creep can cause loosening
- Do not exceed 2500 RPM — bearing failure risk at higher speeds
- Do not apply axial load on shaft — max 10N axial force
- Do not use with gearboxes — too low torque for back-driving loads
- Store with shaft protected — smooth shaft is easily damaged by impact
