Kollmorgen 6SM57S-3.000-G | 3.2Nm Servo Motor with 24V Brake

Description

Kollmorgen 6SM57S-3.000-G | 3.2Nm Servo Motor with 24V Brake

Architect’s Product Breakdown

The Kollmorgen 6SM57S-3.000-G is a compact, short-stack variant of the 6SM57 motor family (covering 6SM27 through 6SM107). Built with high-energy neodymium permanent magnets bonded to the rotor, it provides high power density, rapid acceleration, and precise velocity control.

Model code designation breakdown:

• 6SM: Synchronous Brushless Servo Motor series
• 57: Medium-frame housing and stator diameter (larger than 6SM37)
• S: Short stack length / winding style variant
• 3.000: 3,000 RPM nominal operating speed
• -G: Integrated 24V DC electromagnetic holding brake (24 VDC / M_{br} \ge M_0)

This motor features an embedded resolver for commutation and speed feedback to digital servo drives like the Kollmorgen SERVOSTAR series (300/600/700). The “-G” integrated brake is crucial for vertical or load-bearing axes to prevent z-axis dropping during power loss or E-stop conditions.

Sourcing an exact 6SM57S-3.000-G replacement avoids the mechanical modifications, shaft coupling changes, or drive parameter re-tuning required when migrating to newer motor lines.

6SM57S-3.000-G

Key Technical Specifications

Field Engineer’s Pitfall Guide

• ALWAYS DISENGAGE THE 24V BRAKE BEFORE ENABLING TORQUE: The -G suffix denotes a 24V DC electromagnetic holding brake. The brake is spring-applied (locked when de-energized) and requires 24V DC applied to its coil to release. Applying motor current without supplying 24V to release the brake will burn out both the brake lining and stator windings.
• DO NOT Connect Directly to Mains Voltage: Like all permanent magnet synchronous AC motors, connecting the 6SM57S-3.000-G straight to grid AC power will result in immediate coil destruction or permanent rotor demagnetization.
• Preserve Resolver Alignment: The internal resolver is factory-aligned to the rotor’s magnetic zero position. Disturbing or rotating the rear resolver during field maintenance corrupts commutation angle calculations, leading to motor runaway or immediate drive overcurrent trips.
• Connect Thermal Protection Switch: Ensure the embedded normally closed thermal contact wires are connected to the drive’s thermal monitoring terminals. This prevents thermal overload during continuous high-torque holding cycles.

QA & Testing SOP

1. Mechanical & Electrical Inspection: Verify keyway, shaft runout, and bearing smoothness. Test phase-to-phase stator winding resistance and 1000V DC megohmmeter insulation resistance to ground.
2. 24V DC Brake Function Test: Verify 24V DC brake engagement/disengagement timing, holding torque retention, and current draw on the brake coil.
3. Sinusoidal Back-EMF Audit: Spin the motor on a test bench to confirm clean, symmetrical 3-phase sinusoidal open-circuit back-EMF voltage output.
4. Resolver Alignment & Servo Drive Run: Test resolver signal balance and zero-phase offset. Run under dynamic load connected to a Kollmorgen SERVOSTAR amplifier up to 3000 RPM.
5. ESD & Protective Packaging: Apply protective shaft caps, seal in static-shielding wrap, and pack with heavy-duty foam cushioning.

Technical FAQ

What is the primary difference between the 6SM57S and 6SM57M models?

The S (Short) variant features a shorter stator stack length, delivering 3.2 Nm standstill torque (~0.8 kW). The M (Medium) variant features a longer stack delivering 4.5 Nm standstill torque (~1.1 kW).

What happens if the 24V supply to the brake drops below specification?

If the supply voltage drops below ~20V DC, the holding brake may partially engage or drag against the rotating shaft. This causes excessive friction noise, high motor current draw, and rapid overheating.

Can I replace a 6SM57S-3.000-G with a modern Kollmorgen AKM motor?

Yes, but it is not plug-and-play. Transitioning to an AKM series motor (e.g., AKM4x with brake option) requires verifying mechanical mounting dimensions, choosing a resolver feedback variant, and updating motor configuration parameters in the drive software.