Description
Bosch Rexroth MHD041B-144-PG1-UN | Synchronous Servo Motor
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Motor Series | MHD |
| Motor Size | MHD041B-144-PG1-UN |
| Motor Length | MHD041B-144-PG1-UN |
| Winding Code | MHD041B-144-PG1-UN |
| Encoder | Digital servo feedback with multiturn absolute encoder |
| Shaft | Plain shaft with shaft sealing ring |
| Holding Brake | 2.2 Nm |
| Cooling | Natural convection |
| Continuous Torque at Standstill | 2.7 Nm |
| Continuous Current at Standstill | 7.5 A |
| Rated Torque | 1.4 Nm |
| Rated Current | 2.8 A |
| Rated Speed | 3000 rpm |
| Maximum Speed | 7500 rpm |
| Rated Output | 0.52 kW |
| Rated Voltage | 115 V |
| Rated Frequency | 150 Hz |
| Peak Current | 34 A |
| Torque Constant at 20°C | 0.4 Nm/A |
| Winding Resistance at 20°C | 1.8 Ω |
| Winding Inductivity | 4.9 mH |
| Rotor Inertia | 1.7 × 10⁻⁴ kg·m² |
| Flange Size | 82 mm |
| Centering Diameter | 50 mm |
| Protection | IP65 |
| Insulation Class | F |
| Ambient Temperature | 0 to 40°C |
| Storage/Transport Temperature | -20 to +80°C |
| Approx. Mass | 4.5 kg |
The principal electrical and mechanical values above come from the MHD041B-144 technical documentation. The 2.7 Nm / 7.5 A values apply to the natural-cooling configuration; the same motor family documentation also lists higher values for a different thermal condition, so those figures should not be mixed during drive sizing.
Product Introduction
The Bosch Rexroth Indramat MHD041B-144-PG1-UN is a compact MHD-series permanent-magnet synchronous servo motor intended for controlled machine-axis motion. The variant uses winding code 144, a multiturn absolute digital feedback system, a plain sealed shaft, and a 2.2 Nm holding brake. Its 82 mm flange and 50 mm centering diameter define the principal mechanical interface.
For replacement work, the feedback configuration deserves particular attention. The P code identifies the integrated multiturn absolute encoder, while G identifies the plain shaft with sealing ring and 1 specifies the holding brake; the final UN configuration uses plug-in connections and natural convection cooling.
MHD041B-144-PG1-UN
Application Scenarios & Field Pitfalls — Engineer’s Perspective
Engineering Pain Point
The main replacement risk is not simply matching the MHD041B frame size. A motor with the same mechanical envelope but a different encoder, shaft configuration, brake option, or winding code can create commissioning problems or prevent correct operation with the existing drive.
Typical Applications
- CNC and machine-tool axes
- Packaging and material-handling machinery
- Printing and paper-processing equipment
- Precision positioning and automated production machinery
Technical Pitfalls to Avoid
- Do not substitute by frame size alone.
variants exist with different encoder, shaft, brake, and connection configurations. Confirm the complete type code rather than ordering only an “.” - Do not confuse natural and liquid cooling ratings.
The documentation lists 2.7 Nm continuous standstill torque and 7.5 A for the applicable natural-cooling condition. Liquid-cooling figures should not be applied to this UN configuration. - Verify the feedback system before commissioning.
This model uses an integrated multiturn absolute encoder. Replacing it with a digital-feedback-only variant can affect drive parameterization, position initialization, and machine homing behavior.
Related Products
- — Same basic motor family with digital servo feedback rather than the multiturn absolute encoder configuration.
- — Similar absolute-feedback/plain-shaft configuration without the holding brake.
- MHD041B-144-PG1-UN — Absolute encoder, plain shaft, and 2.2 Nm holding brake; the exact model covered here.
- — Digital servo feedback configuration with keyed shaft and holding brake; mechanical coupling differs from the G-shaft variant.
- — Another absolute-feedback configuration with a keyed shaft.
- MHD041A-144-PG0-UN — Same 041 family and winding code but shorter A-length configuration; mechanical dimensions and performance differ.
- MHD071B-035-PG1-UN — Larger MHD frame family for applications requiring a different torque/speed combination.
- MHD071B-061-PG1-UN — Another MHD071B variant with different winding characteristics.
The MHD family uses the type code to distinguish encoder, shaft, brake, connection, and cooling configurations, so these related models should be treated as functional alternatives rather than automatic drop-in replacements.
Procurement Check
For a replacement purchase, specify the complete designation. Before approving an alternate, compare the motor nameplate, encoder type, brake voltage/current, shaft geometry, connector arrangement, drive parameters, and machine-side coupling.
One useful correction for procurement records: should not be described as a liquid-cooled motor merely because some reseller databases say so. The documented UN configuration is natural convection cooled.
