Rexroth MKD071B-061-KG1-KN

Core Technical Specifications

• Frame Size: 071, Length Code B
• Continuous Standstill Torque: 8.0 Nm
• Rated Torque: 5.3 Nm
• Rated Power: 3.4 kW
• Rated Operating Speed: 4500 rpm
• Maximum Transient Speed: 6000 rpm
• Rotor Moment of Inertia: 8.7×10⁻⁴ kg·m²
• Feedback Definition KG1: Resolver + multi-turn absolute encoder composite feedback
• Winding Code 061: Medium torque, wide speed range winding configuration
• Mounting Flange Dimension: 115 mm outer diameter, centering diameter 95 mm
• Shaft Type: Plain solid shaft with integrated rotary shaft seal
• Holding Brake: Not equipped, KN suffix represents brake-free construction
• Protection Class: IP65
• Cooling Method: Natural surface convection cooling
• Net Weight: 8.8 kg
• Thermal Time Constant: 45 minutes
• Insulation Class: F (155°C maximum allowable winding temperature)
• Operating Ambient Temperature: 0°C ~ +40°C
• Maximum Installation Altitude: 1000 m above sea level; torque derating mandatory for higher altitude
• Supply Matching: Compatible with Rexroth IndraDrive HCS / HDS series servo drives

Function Features

1. Optimized torque-inertia balance, supporting fast acceleration and stable continuous medium-load operation
2. Composite dual feedback system: resolver ensures high-speed dynamic speed loop control; multi-turn absolute encoder retains complete position data after power loss, eliminating mandatory homing after restart
3. Brake-free lightweight rotor design, minimizing rotational inertia to enhance dynamic performance for horizontal transmission axes
4. Full IP65 sealed construction, resistant to workshop dust, cutting fluid splashes and water mist contamination
5. Separated power and encoder aviation connectors on side B layout, reducing electromagnetic crosstalk between power circuit and weak signal circuit
6. Embedded KTY temperature sensor inside stator windings, enabling real-time overheat interlock protection with matched servo drives
7. Standard IEC 115 mm flange, directly compatible with Rexroth medium-size planetary and helical gear reducers
8. Low torque ripple electromagnetic layout, ensuring smooth rotation under low-speed operating conditions

Working Principle

Material & Structural Characteristics

• Motor Housing: Die-cast aluminum alloy with black electrophoretic anti-corrosion coating, externally formed heat dissipation ribs
• Stator and Rotor Core: Low-loss oriented silicon steel laminated sheets to reduce eddy current thermal loss
• Rotor Shaft: Medium carbon steel quenched solid shaft; surface treated for wear resistance
• Bearing Assembly: Precision high-speed rolling bearings filled with long-service high-temperature lubricating grease
• Shaft Seal: Single-layer nitrile rubber rotary seal, blocking fine dust and liquid mist penetration
• Connector Housing: Sealed aluminum alloy rear end cap with two independent waterproof aviation connectors for power and feedback
• Internal Circuit Components: Industrial-grade signal processing PCB installed inside encoder housing

Installation Requirements

1. Standard four-hole IEC flange mounting, recommended tightening torque for fixing bolts: 12 Nm
2. Shaft coupling coaxial deviation must be controlled within ≤0.03 mm to avoid premature bearing fatigue and abnormal vibration
3. Horizontal installation is preferred; vertical mounting is allowed only for non-freefall horizontal loads without self-weight drop risk
4. Adopt original shielded servo power cable and encoder cable supplied by Bosch Rexroth; implement double-end shielding grounding
5. Maintain minimum 25 mm clearance around motor housing to guarantee natural convection heat dissipation
6. Connect motor mounting base to equipment main earth bar to improve EMC anti-interference performance
7. Avoid direct installation adjacent to high-power inverters and contactors to prevent electromagnetic interference

Application Scenarios

• Automated packaging machine feeding axis, cross cutting servo axis
• Printing machinery register adjustment and web transport servo axes
• CNC auxiliary feeding axes, gantry horizontal travelling axes
• Plastic processing machinery take-off and conveying motion systems
• Electronic automated assembly equipment handling and positioning axes
• Metal processing auxiliary positioning servo for cutting and bending equipment
• Automated testing equipment precision displacement drive axes

Operation & Maintenance Notes

1. Do not operate continuously at maximum transient speed for extended cycles; limit high-speed operation to short acceleration and deceleration phases
2. Clean dust, oil mist and cutting debris on motor housing surface every three months to maintain heat dissipation efficiency
3. Avoid striking the front shaft end during installation to prevent bearing deformation and shaft runout
4. Unauthorized disassembly of encoder rear end cap is prohibited; internal absolute position calibration data will be lost after disassembly
5. Regularly inspect aviation connector sealing rubber rings for aging and cracking; replace damaged seals timely
6. Check bearing lubrication status every 10,000 operating hours; replenish or replace grease with Rexroth specified lubricant
7. If abnormal noise or vibration occurs during operation, immediately inspect coupling alignment and mounting bolt tightness