Product Core Brief
- Model: MKD071B-061-KP0-KN (OEM part R911262599)
- Brand: REXROTH (Bosch Rexroth Indramat)
- Series: MKD Permanent Magnet Synchronous Servo Motor
- Core Function: Deliver precise high-dynamic torque for horizontal positioning axes with absolute EnDat position feedback to DIAX04 SERCOS drives.
- Product Type: 071 frame B-length servo motor, side junction box, brake-less, multiturn absolute encoder
- Key Specs: 8.0 Nm continuous stall torque | 4500 rpm max speed | EnDat 2.2 multiturn feedback | Condition: New Original Surplus
- Suffix breakdown: 071 = frame size; B = extended stator stack; 061 = unique winding electrical code; KP0 = side A junction box, no 24 V holding brake; KN = EnDat 2.2 multiturn absolute encoder, sealed keyed output shaft
Product Introduction
The REXROTH pairs with HDS SERCOS servo drives to power horizontal feed axes in semiconductor handling and CNC equipment. It eliminates mandatory homing after power loss via its built-in 4096-turn absolute position tracking.This unit differs from KP1 variants by omitting the integrated holding brake, cutting unit mass by 0.6 kg and reducing standby power draw by 18 W. Field data places its rated MTBF at 46,000 hours under 24/7 constant cycling at 40 °C cabinet ambient.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Continuous stall torque (60 K temp rise) | 8.0 N·m |
| Continuous stall torque (100 K temp rise) | 9.0 N·m |
| Peak short-duration overload torque | 24 N·m (0.5 s max duty) |
| Maximum mechanical speed | 4500 rpm |
| Continuous RMS phase current | 11.2 A |
| Peak overload RMS current | 50.4 A |
| Torque constant Kt (20 °C) | 0.77 N·m/A |
| Phase winding resistance (20 °C) | 1.45 Ω |
| Phase winding inductance | 7.2 mH |
| Rotor moment of inertia | 0.72 × 10⁻⁴ kg·m² |
| Cooling method | Natural surface convection (no auxiliary fan) |
| Encoder standard | EnDat 2.2 bidirectional digital multiturn |
| Absolute tracking range | 4096 full shaft revolutions |
| Single-turn encoder resolution | 2048 lines |
| Output shaft | 24 mm diameter, DIN 6885-1 keyway, integral contact seal |
| Junction box | Side A exit, 240° rotational adjustment |
| Holding brake | None (KP0 designation; no brake coil terminals) |
| Flange mounting dimensions | 115 mm OD flange, 95 mm centering bore, 4×M6 mounting holes |
| Enclosure protection rating | IP65 full housing and shaft seal |
| Winding insulation class | F (155 °C maximum winding temperature) |
| Net motor weight | 3.2 kg |
| Continuous operating ambient temp | 0 °C to +40 °C |
| Storage / transport temperature | -20 °C to +70 °C |
| Compliance certifications | CE, UL, SEMI S2, EN61000 industrial EMC filtering |
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Cross-reference serial number against Rexroth OEM R911262599 database; inspect shaft seal, junction box castings, and encoder housing for scratches or seal damage.
- Live Functional Test: Mount motor to dynamometer bench paired with HDS02.2 SERCOS drive; run 24 hour cyclic torque ramp profiles, log speed stability and absolute position retention via Fluke 115 signal logger.
- Electrical Parameter Test: 500 V Megger insulation test between winding phases and motor ground (pass threshold >10 MΩ); measure three-phase resistance imbalance to stay below 2%.
- Firmware & Encoder Verification: Confirm EnDat 2.2 communication handshake with SERCOS master; photograph junction box cable exit orientation for field installation reference.
- Final QC & Packaging: Fit plastic protective caps to shaft and cable ports, seal unit in anti-static PE bag, apply dated QC Pass label listing torque linearity and encoder position error test results before foam-lined carton packing.
Replacement Pitfall Guide
❗ Firmware Mismatch: Older VisualMotion Toolkit V4 cannot decode EnDat multiturn registers. Upload V5 or newer software before swapping the unit, or the axis will require full homing on every power cycle.❗ Junction Box Exit Misconfiguration: KP0 cables exit fixed to Side A. Swapping for a KP1 Side B motor forces full cable harness rework to avoid cabinet mechanical interference.❗ Shaft Seal Cable Incompatibility: Removing the factory shaft cap before coupling installation scratches the integral IP65 seal. Abraded seals allow cleanroom particulate ingress and accelerate bearing wear.❗ Power Supply Mismatch: The paired HDS SERCOS drive requires a HMV regenerative DC bus supply sized with 20% current headroom. Underrated rectifiers trigger overvoltage faults during fast deceleration.❗ ESD Damage: EnDat encoder ASICs carry low electrostatic tolerance. Always rest the unit on a grounded anti-static mat during cable disconnection, especially in low-humidity cleanroom environments.Keep these in mind and you’ll cut 90% of rework time.
Compatibility Matrix & Benchmarks
Compatibility Matrix
- MKD071B-061-KP1-KN → : Needs Adaptation — remove brake control wiring from drive, vertical axes cannot use this brake-less variant
- MKD071B-060-KP0-KN → : Incompatible — differing winding resistance/inductance creates unstable current loop oscillation
- HDS02.2-W040N-HS12 → : Direct — HS12 SERCOS encoder port natively supports EnDat 2.2 multiturn signals
- PPC-R22.1N-N-Q1-NN-NN-FW → : Direct — motion CPU includes native motor parameter library for winding code 061
Benchmarks
- Axis position scan cycle: 0.4 ms (simulated light load, single motor SERCOS loop)
- Encoder comms throughput: 4 Mbit/s (EnDat 2.2 bidirectional digital protocol)
- Steady-state positioning error: ≤ ±0.1 arcminute (25 °C ambient, full 8 Nm continuous load)
