Product Core Brief
- Model: MSK030C-0900-NN-M1-UG0-NNNN (OEM part R911308683)
- Brand: REXROTH (Bosch Rexroth Indramat IndraDyn S MSK series)
- Series: MSK compact permanent magnet synchronous servo motor family
- Core Function: Deliver fast low-inertia positioning for horizontal pick-and-place, indexing, and small gantry axes with absolute multiturn position feedback to ctrlX DRIVE / ECODRIVE amplifiers.
- Product Type: 030 frame C-length compact servo motor, natural convection cooling, brake-less plain sealed shaft, M1 Hiperface absolute encoder
- Key Specs: 0.8 Nm continuous stall torque | 9000 rpm max mechanical speed | 6.8 A peak output current | IP65 full housing protection | Condition: New Unused Surplus
- Suffix breakdown: 030 = frame size; C = extended stator stack; 0900 = unique winding electrical code; NN = natural convection, no auxiliary fan; M1 = optical Hiperface multiturn absolute encoder; U = 240° rotatable side connector housing; G0 = smooth plain shaft with integral contact seal, no holding brake; NNNN = no optional add-on hardware
Product Introduction
The REXROTH is a compact high-speed servo built for space-restricted automation cells, pairing with HMD dual-axis and DKC standalone servo drives coordinated by CML40 motion PLCs. Its multiturn Hiperface encoder eliminates mandatory machine homing after every power cycle.This unit differs from UG1 braked variants by omitting the integrated 1 Nm 24 V holding brake, cutting unit weight by 0.2 kg and removing brake coil wiring overhead. Field OEM data lists its rated MTBF at 47,000 operating hours under continuous 9000 rpm cyclic light-load operation at 40 °C cabinet ambient.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Continuous stall torque (100 K temp rise) | 0.8 N·m |
| Peak short-duration overload torque | 4.0 N·m (0.5 s maximum duty cycle) |
| Maximum mechanical rotational speed | 9000 rpm |
| Continuous RMS standstill current | 1.7 A |
| Peak overload RMS current | 6.8 A |
| Winding inductance (20 °C) | 14.1 mH |
| Rotor moment of inertia | 0.00003 kg·m² ultra-low inertia |
| Cooling system | Natural surface convection (NN suffix, no blower) |
| Encoder model (M1) | Optical Hiperface multiturn absolute |
| Encoder resolution | 128 signal periods single-turn, 4096 full revolutions multiturn tracking |
| Electrical connector housing | U-type side exit, 240° rotational adjustment for cable routing clearance |
| Output shaft (G0) | 9 mm diameter smooth plain shaft, integrated IP65 contact seal, no keyway |
| Holding brake | None (UG0 designation; no 24 V brake coil terminals inside connector) |
| Flange mounting dimensions | 030 standard compact square flange, four mounting hole pattern |
| Full unit net weight | 1.9 kg |
| Enclosure environmental rating | IP65 full motor housing and shaft seal |
| Winding insulation class | F grade (155 °C maximum winding operating temperature) |
| Continuous operating ambient temp | 0 °C to +40 °C full rated speed; linear performance derate above +40 °C |
| Storage / transport temperature range | -20 °C to +70 °C, non-condensing 5–95% RH |
| Compliance certifications | CE, UL, SEMI S2, EN61000 industrial EMC filtering for cleanroom plasma equipment |
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Cross-reference serial number against Rexroth OEM R911308683 part database; inspect shaft protective red cap for intact factory seal, check connector housing for cracks, encoder rear cover for scratches, and terminal pins for oxidation. Photograph rotatable connector side exit orientation for field installation reference.
- Live Functional Test: Mount motor to low-inertia dynamometer bench paired with HMD01.1N dual-axis drive simulator; run 24 hour cyclic 0–9000 rpm speed ramp and 0–4 Nm overload load profiles. Use a Fluke 115 signal logger to track three-phase winding current balance and absolute encoder position retention over power cycles.
- Electrical Parameter Test: 500 V Megger insulation test between stator windings and motor chassis ground (pass threshold >10 MΩ); verify three-phase winding resistance imbalance stays below 2% at 25 °C ambient temperature.
- Encoder & Connector Verification: Establish full Hiperface bidirectional communication handshake with servo drive firmware; test full 240° connector housing rotation without pin strain or signal dropout; log absolute position drift after 12 hour power-off retention test.
- Final QC & Packaging: Retain factory plastic shaft and connector dust caps; seal unit in anti-static PE foam lined bag, apply dated QC Pass label listing torque linearity, encoder position error, and insulation resistance test metrics before rigid carton shipping.
Replacement Pitfall Guide
❗ UG0 / UG1 Brake Variant Mismatch Risk: UG0 units have no integrated holding brake coil. Swapping this motor into a vertical axis originally fitted with UG1 braked hardware removes load lock functionality and triggers persistent brake circuit open fault codes on the paired servo drive. Always confirm axis orientation (horizontal only for UG0) before replacement.❗ Connector Rotation Cable Interference Risk: The U-type 240° rotatable side connector must be pre-positioned to avoid cabinet structural interference. Fixed-side non-rotatable motor variants require full cable harness rework if routing paths conflict post-swap. Photograph original cable bend radius before disconnecting wiring.❗ Plain Shaft Seal Damage Hazard: Removing the factory red plastic shaft cap prior to coupling installation scratches the integral IP65 contact seal. Damaged seals allow cleanroom particulate ingress that accelerates bearing wear and creates periodic positioning jitter within 3,000 operating hours.❗ Drive Winding Parameter Mismatch Risk: Winding code 0900 has unique resistance and inductance values. Installing this motor into drives loaded with MSK030C alternate winding parameter sets creates unstable current loops, audible stator vibration, and overcurrent trips during fast acceleration to 9000 rpm.❗ ESD Encoder Circuit Damage: The rear Hiperface optical encoder ASIC has low electrostatic discharge tolerance. Always rest the unit on a grounded anti-static mat during connector disconnection or encoder housing inspection, especially in low-humidity cleanroom production environments.Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
Compatibility Matrix
- MSK030C-0900-NN-M1-UG1-NNNN → : Needs Adaptation — remove all 24 V brake control wiring from servo drive logic, only deploy on horizontal non-falling-load axes
- HMD01.1N-W0020-A-07-NNNN → : Direct — native Hiperface encoder input and 6.8 A peak per-axis drive rating fully matches motor electrical specs
- CML40.2-SP-330-NA-NNNN-NW → : Direct — SERCOS II motion bus natively processes M1 multiturn absolute position data without auxiliary signal conditioning
- DKC11.1-040-7-FW → : Direct — ECODRIVE firmware includes pre-stored parameter library for winding code 0900 MSK motors
