REXROTH MSK040C-0450-NN-M1-UG1-NNNN | Servo Motor 0.85kW 400V In Stock

Description

Product Introduction

Machine downtime often traces back to a failing servo axis that won’t hold position under load. The REXROTH MSK040C-0450-NN-M1-UG1-NNNN delivers the torque density needed for compact machine designs without sacrificing dynamic response. This specific configuration features a single-turn absolute encoder and no holding brake, making it ideal for vertical axes where external braking is handled separately or horizontal applications requiring rapid cycling.Why risk performance with generic replacements when cycle times depend on millisecond accuracy? This motor generates 4.2 Nm of stall torque up to 4500 RPM, ensuring consistent acceleration even during peak demand phases. To be frank, the thermal design of the MSK series handles continuous operation at rated load better than many competitors in this frame size. It integrates directly with Rexroth IndraDrive controllers via the standard M1 power connector and UG1 feedback interface, eliminating complex adapter wiring.

Key Technical Specifications

Application Scenarios & Pain Points

The packaging line halted because Axis 3 drifted 0.5mm every cycle, ruining the seal integrity. The root cause wasn’t the PLC logic; it was an aging servo motor losing torque due to demagnetization from overheating. Replacing it with the REXROTH MSK040C-0450-NN-M1-UG1-NNNN restored the original acceleration profile immediately. In high-speed pick-and-place operations, consistent torque delivery is non-negotiable. Without it, you get missed picks, product damage, and frustrated operators constantly resetting faults.

• Semiconductor wafer handlers require smooth motion at low speeds; this motor’s low cogging torque ensures delicate substrates aren’t damaged during transfer.
• Can your current axis accelerate a 5kg payload from 0 to 3000 RPM in under 200 milliseconds? The MSK040C can.
• Textile machinery operating in dusty environments benefits from the IP65 rating, preventing fiber ingress from causing bearing failure.
• Robotics arms in automotive welding cells use these units for joint rotation, relying on the absolute encoder to retain position after power loss.
• Food processing conveyors need washdown-ready components; the stainless steel shaft option (if specified in sub-variants) resists corrosion from acidic cleaners.

Case Study:
A contract manufacturer in Ohio struggled with a labeling machine that frequently faulted on “Following Error.” The integrator had originally installed a lower-torque motor to save costs, but the inertia mismatch caused instability during rapid direction changes. They swapped in a REXROTH MSK040C-0450-NN-M1-UG1-NNNN sourced from our stock. The plant manager reported that within an hour of installation, the following error alarms ceased completely. The line speed increased by 15% because the new motor could handle the aggressive motion profile without tripping. That upgrade paid for itself in less than two shifts of production.

Quality Control Process (SOP Transparency)

We treat every servo motor as a critical component, not just a box on a shelf. Here is our verification protocol for the REXROTH MSK040C-0450-NN-M1-UG1-NNNN:

1. Inbound Inspection: We verify the serial number against Bosch Rexroth’s database format to ensure authenticity. Counterfeit motors often have misaligned nameplates or incorrect font weights. We inspect the shaft for any rust, keyway damage, or signs of prior mounting (scratches on the flange face). The M1 and UG1 connectors are checked for bent pins or pushed-in contacts.
2. Live Functional Test: We mount the motor on a test bench coupled to a calibrated dynamometer and connect it to a Rexroth IndraDrive C controller. We perform a “IDN” identification run to let the drive auto-tune to the motor parameters. We then run a no-load spin-up to 4500 RPM, monitoring vibration levels with an accelerometer. Any vibration exceeding 2.5 mm/s triggers a rejection.
3. Electrical Parameters: Using a Megger tester, we measure insulation resistance between windings and ground at 500 VDC; results must be >100 MΩ. We also measure phase-to-phase resistance with a Kelvin bridge to ensure all three windings are balanced within 1%.
4. Encoder Verification: We read the absolute encoder value via the Hiperface protocol to confirm it communicates correctly and retains data after power cycling. We rotate the shaft manually to verify the position value updates smoothly without dropouts.
5. Final QC & Packaging: After passing all tests, we apply a protective cap to the shaft and spray a light coat of anti-corrosion oil on the flange. The unit is sealed in a vacuum bag with desiccant, padded with custom foam to prevent connector stress, and boxed. A test report including the vibration spectrum and insulation values is included. We can share the test video on request.

Installation Pitfalls Guide (“Lessons Learned”)

Servo motors are precise instruments; treating them like standard induction motors leads to expensive failures. Here are the mistakes I see repeatedly.

1. Feedback Cable Mismatch: The “UG1” in the model number specifies the encoder type and cable pinout. ❗ Do not substitute a generic encoder cable. Using a cable meant for a resolver or a different encoder brand will result in “Encoder Fault” alarms or, worse, uncontrolled motor runaway. Stick to the official Rexroth cable or a verified pin-for-pin equivalent.
2. Brake Wiring Confusion: This specific model (NNNN suffix) does not have an integrated holding brake. If your application requires a brake (e.g., a vertical Z-axis), you must install an external one. Trying to wire a brake voltage to this motor’s connector will do nothing because the terminals don’t exist internally. Check your mechanical design first.
3. Shaft Coupling Stress: Aligning the motor to the gearbox or ballscrew? Even a 0.1mm offset can destroy the bearings in weeks. Use a dial indicator to check runout. Don’t hammer the coupling onto the shaft; use the threaded hole in the shaft end to pull it on gently.
4. Thermal Derating Ignorance: Mounting this motor inside a hot control cabinet or next to a heat source without airflow? You won’t get the rated 0.85 kW. ❗ Check the ambient temperature. If the air around the motor exceeds 40°C, you must reduce the load or add forced cooling, or the thermal sensor will trip the drive.
5. ESD Damage to Encoder: The absolute encoder electronics are sensitive. Touching the open connector pins without an ESD strap in a dry environment can fry the memory chip. We once saw a brand-new motor fail to store its position because a technician handled the plug carelessly. Wear the wrist strap when connecting the feedback cable.