Description
MKD071B-035-KG1-KN | 2500 RPM Servo Motor
Product Introduction
The Bosch Rexroth Indramat MKD071B-035-KG1-KN is an MKD-series permanent-magnet synchronous servo motor intended for closed-loop industrial motion systems. Its 071 frame, 035 winding, resolver-based feedback system, plain shaft, and integrated holding brake define a specific mechanical and electrical configuration rather than a generic MKD071 replacement.
For legacy machine maintenance, the important combination is the 8.0 Nm continuous standstill torque, 2,500 RPM speed rating, 5 Nm holding brake, and resolver feedback with integrated absolute position detection beyond 4,096 revolutions. The motor uses a 115 mm flange and 95 mm centering diameter, making those dimensions important when checking a mechanical replacement.
MKD071B-035-KG1-KN
Key Technical Specifications
- Manufacturer: Bosch Rexroth Indramat
- Model: MKD071B-035-KG1-KN
- Material/Order Number: R911272415
- Series: MKD Synchronous Motors
- Motor Size: 071
- Motor Length: B
- Winding Code: 035
- Product Type: Permanent-magnet synchronous servo motor
- Continuous Standstill Torque: 8.0 Nm
- Continuous Standstill Current: Approximately 5.8 A
- Speed Rating: 2,500 RPM
- Maximum Speed: 4,500 RPM
- Torque Constant at 20°C: 0.91 Nm/A
- Winding Resistance at 20°C: 7.2 ohms
- Winding Inductance: 25.3 mH
- Feedback: Resolver with integrated multiturn encoder
- Position Detection: Absolute, greater than 4,096 revolutions
- Shaft Design: Plain shaft
- Shaft Seal: Yes
- Holding Brake: Yes
- Holding Brake Torque: 5 Nm
- Brake Release: 24 VDC
- Connection Type: Connection box
- Connection Direction: Side B
- Flange Size: 115 mm
- Centering Diameter: 95 mm
- Protection Rating: IP65
- Cooling: Natural convection; compatible configurations may use surface/blower cooling
- Motor Weight: Approximately 8.8 kg
Application Scenarios & Pain Points
1. Legacy Indramat Servo-Axis Replacement
The MKD071B-035-KG1-KN is suitable for maintenance replacement where the existing machine uses the same MKD071B-035 configuration.
Pain point: Matching only the 071 frame is insufficient. The winding, feedback, shaft, brake, and connection configuration must also agree.
2. CNC and Machine-Tool Motion
The motor’s resolver/absolute feedback arrangement and 8.0 Nm standstill torque make it applicable to closed-loop machine axes requiring controlled positioning.
Pain point: A replacement motor with a different feedback system can require drive parameter changes or may be electrically incompatible.
3. Vertical or Load-Holding Servo Axes
The integrated 5 Nm holding brake provides mechanical holding when the servo axis is de-energized.
Pain point: Brake torque must be compared with the actual static load torque. The brake should not automatically be treated as a dynamic stopping device.
4. Packaging and Automated Production Machinery
The MKD071B frame can be used in multi-axis automation where a compact synchronous servo motor interfaces with an Indramat motion-control system.
Pain point: Side-B connection orientation and the 115 mm flange can matter when the replacement is installed in a confined machine enclosure.
5. Obsolete-System Maintenance Stock
This model is a practical candidate for maintenance inventory where production equipment still depends on legacy Rexroth Indramat MKD motors.
Pain point: Long-term storage does not prove operational condition. Incoming inspection should cover insulation, bearings, brake operation, feedback, and winding balance before the motor is placed into critical spares inventory.
QA & Live Testing SOP
1. Identity and Configuration Verification
- Photograph the complete motor nameplate.
- Confirm MKD071B-035-KG1-KN.
- Verify material/order number R911272415 where marked.
- Confirm winding code 035.
- Confirm the KG1 configuration.
- Record serial number and manufacturing information for traceability.
2. Mechanical Inspection
- Inspect the 115 mm mounting flange.
- Verify the 95 mm centering diameter.
- Inspect the plain shaft for scoring, corrosion, dents, or coupling damage.
- Check the shaft sealing area.
- Rotate the shaft manually and listen for abnormal bearing noise.
- Check for excessive radial or axial play.
3. Brake Verification
- Use a controlled 24 VDC brake supply.
- Verify that the brake releases cleanly when energized.
- Remove brake power and confirm positive mechanical engagement.
- Check brake current against the applicable motor documentation.
- Do not repeatedly cycle the brake at high frequency during an incoming inspection.
- Do not use the holding brake as a substitute for a safety-rated dynamic stopping system.
4. Motor Winding Test
- Measure resistance between all motor phases.
- Compare phase-to-phase readings for balance.
- Perform insulation-resistance testing using an appropriate procedure for the motor.
- Check each phase against the motor frame.
- Record all readings with ambient temperature.
- Do not apply uncontrolled test voltage to the resolver/encoder electronics.
5. Resolver and Encoder Verification
- Inspect the connection box and feedback wiring.
- Check terminals for corrosion, looseness, or mechanical damage.
- Connect only to a compatible Rexroth/Indramat test drive.
- Verify resolver feedback detection.
- Confirm correct direction and feedback response at low speed.
- Verify absolute/multiturn position behavior through the compatible control system.
6. Controlled Rotation Test
- Start at low speed with current limits enabled.
- Confirm correct rotation direction.
- Monitor motor current and following error.
- Check for abnormal vibration or bearing noise.
- Increase speed progressively only within the verified test-rig limits.
- Do not use the maximum-speed value as a routine commissioning speed.
7. Packaging and Traceability
- Protect the shaft from impact.
- Protect the connection box and feedback wiring from mechanical loading.
- Use ESD-safe handling around feedback circuitry.
- Package the motor so the rotor shaft cannot be subjected to transport shock.
- Record nameplate photographs, serial number, winding test results, brake test, feedback test, and rotation-test results.
Field Engineer’s Pitfall Guide
❗ Do not substitute by frame size alone.
The family includes multiple winding and feedback configurations. The 035 winding and KG1 configuration are part of the required identity.
❗ KG1 is not the same as KP1.
The KG1 version uses a plain shaft, while KP-series configurations use a different shaft arrangement. Confirm the coupling interface before approving a replacement.
❗ Do not confuse brake torque with motor torque.
The holding brake is rated at 5 Nm, while the motor’s continuous standstill torque is 8.0 Nm. These are different specifications with different engineering purposes.
❗ Verify the speed rating against the exact documentation/nameplate.
Available documentation is not completely consistent on speed terminology. A commonly published configuration value is 2,500 RPM speed rating and 4,500 RPM maximum speed. Do not substitute a conflicting speed figure without confirming the exact motor documentation.
❗ Cooling changes the usable torque envelope.
Published data distinguishes natural/convection cooling from surface or blower-assisted cooling. Do not apply a surface-cooling torque value to a naturally cooled installation without checking the applicable duty-cycle documentation.
❗ Check the drive before energizing.
Resolver feedback, winding code, motor parameters, brake control, and current limits must be compatible with the installed Indramat drive.
Intent-Driven FAQ
What is the Bosch Rexroth -035-KG1-KN?
It is a Bosch Rexroth Indramat MKD synchronous servo motor with a 071 frame, 035 winding, resolver feedback with integrated multiturn absolute position detection, plain shaft, and integrated holding brake.
What is thenumber for ?
The documented material/order number is R911272415.
What is the continuous standstill torque?
The commonly documented natural-cooling value is 8.0 Nm continuous torque at standstill.
What is the speed rating?
The published speed rating is 2,500 RPM. Some documentation separates rated speed, characteristic speed, and maximum speed, so the exact nameplate and applicable project-planning documentation should be checked before defining the machine’s operating limit.
Does this motor have a brake?
Yes. The KG1 configuration includes a 5 Nm holding brake with 24 VDC brake actuation.
Does the use a keyed shaft?
No. This configuration uses a plain shaft with a shaft seal.
What feedback does it use?
The motor uses resolver feedback with an integrated multiturn encoder, with absolute position detection exceeding 4,096 revolutions.
What are the mounting dimensions?
The documented mechanical interface uses a 115 mm flange and 95 mm centering diameter.
Is the a direct replacement forMKD071B motor?
No. The complete model code must match the application’s winding, feedback, shaft, brake, connection, and mechanical requirements. An motor with a different suffix should not be treated as automatically interchangeable.
What should be verified before purchasing a used or surplus unit?
Verify the complete nameplate, R911272415 order number, serial number, shaft condition, brake operation, winding balance, feedback condition, connector/connection-box condition, and compatibility with the installed Rexroth drive.
