Description
- Model: MKD025B-144-KG1-UN
- Brand: Rexroth (Indramat)
- Series: MKD (Synchronous Motors for IndraDrive/IndraDyn)
- Core Function: High-precision motion control for automation and CNC applications
- Product Type: Permanent Magnet AC Servo Motor (New Surplus)
- Key Specs: 0.9 Nm Continuous Torque | 5000 RPM Max Speed | Resolver Feedback
- Motor Frame Size: 025 (Small footprint for high-density machines)
- Winding Code: 144 (Optimized for specific voltage/current response)
- Continuous Torque (at Standstill): 0.9 Nm (Md)
- Continuous Current (at Standstill): 1.3 A (Id)
- Maximum Speed: 5000 RPM (nmax)
- Feedback System: Resolver (Integrated for commutation and positioning)
- Shaft Design: Plain shaft with shaft sealing ring (Provides IP65 protection)
- Holding Brake: No holding brake (indicated by “N” in the code)
- Connection: Power and Feedback connectors located on the housing
- Insulation Class: F (Standard industrial thermal rating)
REXROTH MKD025B-144-KG1-UN
Installation & Commissioning Guide
Phase 1: Preparation (Pre-Installation)
⚠️ Safety First:
- Ensure the IndraDrive or Indramat controller is powered down and the DC link is discharged before connecting motor cables.
- Mounting Check: Verify the flange surface is clean. The MKD series relies on the flange for a portion of its heat dissipation.
- Shaft Alignment: Ensure the coupling to the load is perfectly aligned. Even a 0.1 mm misalignment can cause premature bearing wear or resolver “noise.”
Phase 2: Mechanical Installation
- Coupling: If your model has the plain shaft (UN), ensure the coupling set screws are torqued to the manufacturer’s spec to prevent slipping under high-dynamic acceleration.
- Orientation: The motor can be mounted in any orientation (horizontal/vertical). If mounted vertically with the shaft up, ensure no liquids can pool at the shaft seal.
- Earthing: Ensure the motor frame is properly grounded through the machine bed or a dedicated ground wire.
Phase 3: Electrical Connection
- Power Cable: Use original Rexroth IKG or RKG cables. Non-shielded cables can cause EMI, leading to “Encoder Faults” or “Velocity Loop” errors in the drive.
- Resolver Cable: Connect the feedback cable carefully. These pins are delicate—do not force the connector if it doesn’t align easily.
- Sealing: Tighten the connector locks to maintain the IP65 rating, especially in environments with oil mist or coolant.
Phase 4: Parameterization & Testing
- Drive Software: Use IndraWorks or DriveTop to load the motor parameter file for MKD025B-144.
- Commutation: Since this is a resolver-based motor, the commutation offset is factory-set. The drive should recognize the motor’s position automatically upon initialization.
- Jog Test: Perform a low-speed jog test without the load attached to verify the rotation direction and smoothness.
REXROTH MKD025B-144-KG1-UN
Customer Cases & Industry Applications
Case 1: Precision Labeling Machine Downtime
Situation: A pharmaceutical packaging facility in Italy used MKD025B-144-KG1-UN motors on their high-speed labeling carousels. One motor developed an internal short, causing the IndraDrive to trip with an “Overcurrent” alarm.
Task: The labeling line is the bottleneck of the facility. The manufacturer’s lead time for a new MKD motor was 12 weeks as they are now focused on the newer MSK series.
Action: We provided a New Surplus MKD025B-144-KG1-UN from our stock. Because it was a “drop-in” replacement, no mechanical modifications or software reprogramming were required.
Result: The motor was replaced and the line was back to 100% capacity within 48 hours. The maintenance manager noted: “Finding an original MKD in new condition saved us from a very expensive system retro-fit.”
Case 2: CNC Tool Changer Reliability
Situation: A precision machine shop in the USA had an MKD motor on a CNC tool changer that was failing intermittently due to fluid ingress in the old resolver.
Task: The shop needed a replacement with a fresh shaft seal and pristine internals to ensure another 10+ years of maintenance-free operation.
Action: We supplied the exact KG1-UN variant. As a New Surplus item, the internal bearings and seals are in factory-new condition, unlike “Refurbished” units which often use generic parts.
Result: The tool changer’s cycle time was stabilized, and the “Encoder Data Error” messages disappeared. The customer now stocks one extra unit from us as a strategic spare.
REXROTH MKD025B-144-KG1-UN
Frequently Asked Questions (FAQ)
Q: Can I use this motor with an HCS01 IndraDrive? A: Yes. The MKD series is fully compatible with the IndraDrive platform (HCS, HMU, etc.) as long as the drive is equipped with a resolver interface.
Q: What is the difference between the “UN” and “KN” versions? A: “UN” indicates a plain shaft without a keyway and no holding brake. “KN” would indicate a shaft with a keyway and no holding brake. If your coupling requires a keyway, you would need the “K” version.
Q: Why choose “New Surplus” over a local motor repair? A: Resolvers are notoriously difficult to align precisely outside of a factory environment. A local repair might fix the winding, but if the resolver is off by even a few degrees, the motor will lose torque or run hot. New Surplus provides factory-level precision.
Q: Is the MKD025B waterproof? A: It is rated IP65, meaning it is dust-tight and protected against water jets. However, it should not be submerged. For high-pressure washdown, a secondary shield is recommended.
Q: Does it come with the mounting bolts? A: No, mounting hardware is typically part of the machine assembly. It uses standard metric flange mounting.
