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Kollmorgen B-404-C-31
Product Overview:
The B-404-C-31 is a brushless DC servo motor from Kollmorgen’s B-series product line. It shares the same 404 frame and C stack length as the B-404-C-A3 but features a different winding configuration designated by “31”. The “31” winding is optimized for higher voltage operation and different torque-speed characteristics compared to the A3 variant. This motor targets applications requiring higher speed or different voltage compatibility.
Detailed content
Key Specifications:
| Parameter | Value |
|---|---|
| Frame Size | B-404 (40 × 40 mm body) |
| Stack Length | C (medium length) |
| Winding Code | 31 |
| Continuous Torque (Rated) | 0.17 Nm (15.0 in-lb) |
| Peak Torque (10 sec) | 0.51 Nm (45.1 in-lb) |
| Rated Speed | 6000 RPM |
| Max Speed | 10000 RPM |
| Rated Power (Continuous) | 107 W |
| Peak Power | 320 W |
| Voltage Rating (31 winding) | 48 VDC |
| Encoder Type | Incremental, 500 lines/rev (A/B/Z channels) |
| Shaft Diameter | 8 mm, with keyway (0.8 × 0.4 mm) |
| Shaft Length | 18 mm (from front face) |
| Motor Weight | Approximately 0.38 kg (0.84 lb) |
| Operating Temperature | -10°C to +50°C |
Construction & Materials:
- Stator: Silicon steel laminations, Class B insulation, slot-wound copper
- Rotor: NdFeB permanent magnets, 4-pole configuration
- Shaft: Hardened stainless steel, 8 mm diameter
- Housing: Aluminum alloy, anodized black
- Bearings: Shielded ball bearings, lubricated for life
- Commutation: 3-phase, 6-step or sinusoidal (drive-dependent)
Performance Parameters:
| Parameter | Value |
|---|---|
| Torque Constant (Kt) — 31 | 0.0056 Nm/A (5.6 mNm/A) |
| Voltage Constant (Ke) — 31 | 0.56 V/krpm |
| Phase Resistance (25°C) — 31 | 12.8 Ω (phase-to-phase) |
| Phase Inductance — 31 | 1.2 mH (phase-to-phase) |
| Max Continuous Current — 31 | 3.0 A (RMS) |
| Peak Current (10 sec) — 31 | 9.0 A |
| Rotor Inertia | 0.000012 kg·m² (12 g·cm²) |
| Mechanical Time Constant (τm) | 1.1 ms |
| Electrical Time Constant (τe) | 0.09 ms |
Advantages:
- 48 VDC operation — higher voltage enables lower current for same power, reducing I²R losses in cabling
- Higher max speed (10,000 RPM) — suitable for high-speed spindle and fan applications
- Same compact footprint as A3 — drop-in mechanical replacement with different electrical characteristics
- Low winding inductance — fast current response, high servo bandwidth
Applicable Industries:
- High-Speed Spindles — dental drills, micro-machining spindles
- Fan & Blower Drives — HVAC, electronic cooling
- Textile — high-speed yarn guides
- Printing — anilox roll drives
- Robotics — high-speed joint actuators
Installation Requirements:
- Identical mounting to B-404-C-A3 — M3 mounting holes, 8 mm shaft with keyway
- Wiring: 6 motor leads + 3 encoder leads
- Drive must be configured for 48 VDC bus and 31 winding parameters
- Ensure cable length < 5 m for 48 VDC to minimize voltage drop at peak current
Usage Notes:
- Winding 31 is NOT interchangeable with A3 — different Kt, Ke, resistance, and voltage rating
- Higher speed rating (10,000 RPM) — verify bearing life at target speed
- At 48 VDC, peak current is lower than A3 variant — drive current limit must be set accordingly
- Do not operate below 10% rated speed without forced cooling — commutation ripple increases at low speed
