Optimizing dynamic response in high-performance motion control systems, the Mitsubishi Electric HG-KR73BJ AC Servo Motor provides precise positioning capability within the MELSERVO-J4 automation platform. This low-inertia, small-capacity rotary motor is engineered with an integrated electromagnetic brake and a factory-installed oil seal, making it highly suited for vertical axis applications and environments requiring protection against fluid ingress.
Key Features
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Low Inertia Design: Optimized for high-frequency positioning cycles and rapid acceleration/deceleration profiles.
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Electromagnetic Holding Brake: Integrated brake (B-suffix) ensures secure position retention during power-off states, preventing vertical axis drop.
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Integrated Oil Seal: Factory-fitted shaft oil seal (J-suffix) prevents gear lubricant or cutting fluid migration into the motor housing.
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High-Resolution Feedback: Compatible with absolute/incremental encoders to deliver sub-micron positioning accuracy.
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Industrial Protection: Designed to withstand challenging industrial environments when paired with appropriate IP-rated cabling.
Typical Applications
- Vertical axis drive systems requiring safety holding brakes.
- Packaging, filling, and sealing machinery.
- High-speed material handling gantries and pick-and-place systems.
- Semiconductor manufacturing and PCB assembly equipment.
Technical Specifications
| Manufacturer |
Mitsubishi Electric |
| Model Number |
HG-KR73BJ |
| Series |
HG-KR (Low Inertia, Small Capacity) |
| Rated Output |
0.75 kW |
| Rated Speed |
3000 r/min |
| Maximum Speed |
6000 r/min |
| Rated Torque |
2.4 N-m |
| Maximum Torque |
8.4 N-m |
| Rated Current |
4.8 A |
| Electromagnetic Brake |
Yes (Holding Brake) |
| Oil Seal |
Yes |
| Insulation Class |
130 (B) |
| Vibration Rank |
V10 |
| Environmental Rating |
Indoors, free from corrosive/flammable gases, oil mist, and dust |
| Net Weight |
3.8 kg |
| Shipping Weight (Calculated) |
5.0 kg |
Empirical Engineering Insights
Alternative Models & Compatibility
The HG-KR73BJ is designed for direct pairing with the MR-J4-70A, MR-J4-70B, or MR-J4-70GF servo amplifiers. When migrating from legacy HF-KP series motors, note that parameter adjustments are required in MR Configurator2 to accommodate the higher-resolution encoder feedback and different physical inertia ratios.
Application Pitfalls & Engineering Notes
The integrated electromagnetic brake is strictly a holding brake and must never be used for dynamic deceleration or emergency stopping of moving loads. Repeated dynamic braking cycles will wear out the friction plates, leading to holding failure. Ensure the control sequence releases the brake prior to enabling the servo amplifier drive stage.
Commissioning & Wiring Tips
Always route the encoder feedback cable separately from the high-voltage motor power and brake cables to prevent electromagnetic interference. Ensure the motor frame is grounded directly to the servo amplifier's protective earth (PE) terminal to eliminate high-frequency noise currents.
Installation Guidelines
CRITICAL WARNING
Ensure all main power sources are completely de-energized and locked out before attempting installation or maintenance. Wait at least 15 minutes for the servo amplifier's internal bus capacitors to discharge fully. Verify zero voltage across the terminals before handling connections.
1
Mount the motor securely to a rigid machine base using the specified flange mounting bolts, ensuring correct alignment with the driven shaft to prevent premature bearing wear.
2
Connect the motor power, electromagnetic brake, and encoder cables, ensuring all connectors are fully seated and locked to maintain environmental protection ratings.
3
Configure the servo amplifier parameters to match the HG-KR73BJ motor profile, and perform a low-speed test run to verify rotation direction and brake operation before full commissioning.