Component Snapshot At-a-Glance

• Model: MHD093C-035-NG0-BA
• Alt. P/N: No direct drop-in cross part; sibling variants NG1, LA/BA power connector direction variants
• Product Series: Rexroth Indramat MHD permanent magnet synchronous servo motor platform
• Hardware Type: High-torque natural convection AC brushless servo motor
• Key Feature: NG0 digital servo feedback encoder, natural convection cooling, plain shaft without holding brake, IP65 full motor housing
• Primary Field Use: High dynamic torque, position & velocity control for CNC machine tools, metal stamping presses, heavy-duty automated handling and extrusion equipment

 

Hard-Numbers: Technical Specifications

• Feedback Protocol: NG0 digital serial servo encoder (motor electronic nameplate memory onboard)
• Connector Layout: Power cable outlet Side B; separate encoder D-Sub signal port
• Rated Mechanical Data:
  • Standstill continuous torque: 23 Nm
  • Rated torque: 9.2 Nm
  • Rated speed: 2500 RPM; max speed 6000 RPM
  • Continuous standstill current: 18.5 A RMS
  • Rated operating current: 5.2 A RMS
• Mechanical Dimensions:
  • Flange standard: DIN 424948, 140/150mm flange, 130mm centering diameter
  • Shaft: 32mm plain smooth shaft with integrated shaft seal ring
  • Weight: 23.5 kg (no external blower)
• Cooling & Ambient: Natural convection housing; rated 0 °C ~ +40 °C full torque; derate output above 40 °C
• Storage Temperature: -40 °C to +85 °C
• Ingress Protection: IP65 motor housing (shaft seal + cable gland sealed construction)
• Isolation & Insulation: Stator winding 1500 VAC surge tested class F insulation
• Brake Configuration: NG0-BA variant – no integrated holding brake
• Mounting: Universal 4-hole flange, all installation orientations, compatible with pulley/gearbox overhung mounting
• Drive Compatibility: Matches Rexroth HDS02.2, DDS, HDD IndraDrive series servo amplifiers
• Thermal Protection: Embedded PTC winding temperature sensor for drive overheat trip logic

 

The Real-World Problem It Solves

Smaller frame servo motors cannot deliver sustained 23Nm standstill torque for heavy metal cutting and stamping loads, forcing oversized multi-motor setups that consume extra machine footprint and rack power. Analog resolver-only motors lack onboard motor ID memory; technicians must manually input winding, pole and encoder parameters every motor swap, introducing human error and axis positioning faults. Unsealed IP54 motors ingest coolant mist, metal dust and workshop humidity, leading to bearing corrosion and stator winding short failures within 1–2 years. Motors without natural convection blowers add auxiliary fan hardware, extra wiring and regular filter cleaning maintenance overhead.Where you’ll typically find it:

• Vertical/horizontal CNC machining center spindle and heavy feed axis drives
• Metal stamping, punch press and bending machine synchronized servo axes
• Large extrusion and injection molding transfer robotic handling systems
• Heavy-duty palletizing & automotive body assembly multi-axis automation lines

Bottom-line value statement: 23Nm high continuous torque natural convection IP65 servo with self-identifying NG0 digital encoder eliminates manual motor parameter setup, resists workshop coolant/debris contamination and removes auxiliary cooling fan maintenance requirements for heavy-load machine axes.

 

Hardware Architecture & Under-the-Hood Logic

This permanent magnet synchronous motor relies on matched IndraDrive servo amplifiers for all current/velocity/position loop processing; the NG0 encoder stores complete motor electronic data to auto-configure drive loop gains on power-up. Separate sealed power and signal cable glands prevent coolant ingress to internal windings and feedback electronics.

1. Three-phase stator copper windings with embedded PTC thermal sensors monitor winding temperature continuously during operation
2. High-energy rare-earth permanent magnet rotor delivers flat torque curve across full 0–6000 RPM speed range
3. NG0 digital encoder mounted rear of rotor shaft captures high-resolution position/velocity data; non-volatile memory stores motor pole count, winding resistance, thermal model parameters
4. Side-B power connector gland fully sealed IP65 to block machine coolant, oil mist and metal particulate contamination
5. Integrated shaft lip seal prevents gearbox/pulley lubricant leakage and dust intrusion into front motor bearing
6. Natural convection finned housing dissipates winding heat without auxiliary fans; heat transfer optimized for continuous heavy static torque loads
7. Encoder D-Sub port transmits serial digital feedback to servo drive to execute closed-loop position control without signal analog drift

 

Field Service Pitfalls: What Rookies Get Wrong

Mismatched NG Encoder Variants During Motor Replacement

New technicians swap NG1 encoder motors into machines configured for NG0 feedback. Encoder handshake fails; drive throws permanent feedback fault and axis cannot home or move.

• Field Rule: Verify suffix NG0 before installation; re-run motor auto-identification in IndraWorks software post-motor swap to validate electronic nameplate readout.

Unsealed Generic Cable Glands Breaking IP65 Rating

Junior crews install non-Rexroth unshielded cable glands on power/encoder connectors. Coolant mist penetrates motor housing, causing stator winding ground faults within weeks of production operation.

• Quick Fix: Only OEM shielded cable glands permitted; apply silicone sealant around gland threads after cable termination.

Parallel Routing of Unshielded Encoder Cable Next to Motor Power Cables

Field technicians run encoder multi-pin wiring alongside high-current U/V/W motor power harnesses without separation. IGBT switching noise corrupts digital position signals, triggering following error trips and random axis stall faults during heavy cutting loads.

• Field Rule: Separate encoder shielded cables a minimum 30cm from motor power lines; ground encoder cable shield only at servo drive cabinet terminal end.

Overlooking PTC Thermal Sensor Continuity Test Post-Motor Rewind

After bearing/winding overhaul, techs fail to check PTC temperature sensor wiring continuity. Drive loses overheat protection, allowing winding burnout under sustained heavy torque cycles.

• Field Rule: Measure PTC resistance with handheld multimeter before mounting motor back to machine; confirm drive thermal trip alarm triggers in IndraWorks diagnostic menu.

Improper Shaft Seal Lubrication During Pulley/Gearbox Installation

Techs mount pulleys dry without light grease on the motor shaft lip seal. Dry seal friction creates premature wear, leading to coolant ingress and bearing rust failure.

• Field Rule: Apply thin layer of compatible high-temperature bearing grease to shaft surface before sliding on pulleys or couplings.

 

Commercial Availability & Pricing Note

Please note: The listed price is for reference only and is not binding. Final pricing and terms are subject to negotiation based on current market conditions and availability.