Introduction

The Allen Bradley MPL-B310P-RK72AA Servo Motor is part of the MP-Series MPL family of low-inertia brushless servo motors. It is designed for industrial automation systems where controlled speed, accurate feedback, and responsive motion are important.

The RK72AA configuration combines a resolver feedback system with a keyless shaft and no brake. This configuration differentiates it from the closely related RJ72AA model, which uses a keyed shaft. It also differs from the RK74AA configuration, which adds a 24 V DC holding brake.

The motor has a 100 mm frame size and 25.4 mm magnet stack, giving machine builders a compact servo package for a variety of automated axes. Its 5000 RPM rating makes it suitable for applications requiring relatively high rotational speed.

The resolver feedback system is an important consideration when selecting this motor. Engineers should verify that the servo drive and motion controller support the required resolver interface before selecting the RK72AA as a replacement.

Another practical feature is the keyless shaft extension. This configuration is particularly useful when the machine uses compatible clamping-style couplings and does not require a traditional shaft key. Correct mechanical alignment is essential, especially when the motor is operated at high speed.

The motor's SpeedTEC DIN right-angle connector can rotate 180 degrees, allowing installers to adjust the connector orientation to suit the machine layout. This can make cable routing cleaner and reduce unnecessary bending around the motor.

For industrial spare-parts inventories, the complete MPL-B310P-RK72AA catalog number should be used when identifying this motor. Resolver feedback, shaft configuration, brake option, and frame/stack combination should all be checked before purchasing a replacement.

Technical Specifications

Specification	MPL-B310P-RK72AA
Brand	Allen Bradley / Rockwell Automation
Product Family	MP-Series MPL
Product Type	Low-Inertia AC Rotary Servo Motor
Catalog Number	MPL-B310P-RK72AA
Armature Voltage	460 V AC
Voltage Class	400 V class
Rated Speed	5000 RPM
Continuous Stall Torque	1.58 N·m
Rated Output	Approx. 0.77 kW
Frame Size	100 mm (3.94 in.)
Magnet Stack Length	25.4 mm (1.0 in.)
Feedback	2-Pole Resolver
Shaft	Keyless Shaft Extension
Brake	No Brake
Connector	SpeedTEC DIN Connector
Connector Type	Right Angle
Connector Rotation	180° Rotatable
Mounting	IEC Metric, Free Mounting Holes, Type FF
Enclosure	IP66
Motor Construction	Brushless Permanent-Magnet Servo Motor
Frame Dimension	100 mm
Magnet Stack Dimension	25.4 mm
Weight	2.70 kg (5.95 lb)

The actual operating performance depends on the selected servo drive, feedback configuration, mechanical load, duty cycle, ambient conditions, and motion-control tuning.

Recommended Related Models

Model	Product Type	Key Configuration
MPL-B310P-RJ72AA	Servo Motor	Resolver, keyed shaft, no brake
MPL-B310P-RJ74AA	Servo Motor	Resolver, keyed shaft, 24 V DC brake
MPL-B310P-RK72AA	Servo Motor	Resolver, keyless shaft, no brake
MPL-B310P-RK74AA	Servo Motor	Resolver, keyless shaft, 24 V DC brake
MPL-B310P-HK72AA	Servo Motor	Incremental feedback, keyless shaft, no brake
MPL-B310P-HK74AA	Servo Motor	Incremental feedback, keyless shaft, 24 V DC brake
MPL-B310P-SK72AA	Servo Motor	Single-turn high-resolution feedback, keyless shaft, no brake

These models are useful alternatives when the application requires a different feedback system, shaft arrangement, or brake configuration.

Popular Related Models

Model	Product Family	Typical Configuration
MPL-B310P-MK72AA	MP-Series MPL	Multi-turn absolute feedback, keyless shaft, no brake
MPL-B310P-MK74AA	MP-Series MPL	Multi-turn absolute feedback, keyless shaft, brake
MPL-B310P-MJ72AA	MP-Series MPL	Multi-turn absolute feedback, keyed shaft, no brake
MPL-B310P-MJ74AA	MP-Series MPL	Multi-turn absolute feedback, keyed shaft, brake
MPL-B310P-HK72AA	MP-Series MPL	Incremental feedback, keyless shaft, no brake
MPL-B310P-HK74AA	MP-Series MPL	Incremental feedback, keyless shaft, brake
MPL-B310P-SK74AA	MP-Series MPL	Single-turn high-resolution feedback, keyless shaft, brake

The MPL-B310P-RK72AA is a strong choice when a machine specifically requires resolver feedback, a keyless shaft, and no integrated brake. For replacement applications, always verify the complete motor catalog number and the connected servo-drive feedback requirements before installation.

Applications

Packaging Machinery

The MPL-B310P-RK72AA can be used for indexing, feeding, cutting, sealing, labeling, and other rotary movements in automated packaging equipment. Its low-inertia design supports rapid changes in speed and position during repetitive production cycles.

Material Handling

The motor can drive conveyors, indexing tables, transfer mechanisms, and other automated handling equipment requiring controlled rotary motion.

Automated Assembly

Assembly systems often require accurate and repeatable positioning. The resolver feedback provided by this model can be integrated into compatible servo-control architectures for controlled axis movement.

Printing and Converting

Printing, winding, feeding, slitting, and converting machines can benefit from a servo motor capable of maintaining controlled speed and coordinated motion.

Machine Tools

With a 5000 RPM rating and low-inertia construction, the motor can be considered for suitable machine-tool and automated machining applications requiring responsive rotary motion.

Industrial Machine Retrofit

The MPL-B310P-RK72AA is especially relevant when replacing an existing MPL servo motor that uses resolver feedback and a keyless shaft. Matching the complete feedback and mechanical configuration can simplify retrofit planning.

Advantages

Low-Inertia Brushless Design

The MPL-B310P-RK72AA uses a low-inertia permanent-magnet servo construction designed for responsive motion. This is advantageous in applications involving frequent acceleration, deceleration, indexing, and direction changes.

Resolver Feedback

A 2-pole resolver provides motor position feedback to a compatible servo drive. Resolver-based systems can be a strong choice for industrial environments where robust feedback operation is important.

5000 RPM Speed Rating

The motor is rated for operation up to 5000 RPM, providing sufficient speed for many high-cycle industrial motion applications.

Keyless Shaft

Unlike keyed versions of the same motor family, the RK72AA uses a keyless shaft extension. This configuration can provide a clean coupling interface when used with a compatible clamping hub or coupling.

No Integrated Brake

The RK72AA is a no-brake configuration. This makes it appropriate for axes that do not require an integrated holding brake or where the machine uses a separate mechanical holding mechanism.

Flexible Connector Position

The right-angle SpeedTEC DIN connector can rotate through 180 degrees, making it easier to route motor and feedback cables in compact machine installations.

IEC Metric Mounting

The 100 mm IEC metric frame with free mounting holes provides practical mechanical flexibility when integrating the motor into industrial equipment.

Technical FAQs

1. What feedback technology does the MPL-B310P-RK72AA use?
The motor uses a 2-pole resolver for position feedback. The connected servo drive must be compatible with the resolver feedback interface.

2. What is the rated speed of the MPL-B310P-RK72AA?
The motor has a rated speed of 5000 RPM. The actual operating speed depends on the servo drive, mechanical load, duty cycle, and application configuration.

3. Does this motor include an integrated brake?
No. The MPL-B310P-RK72AA is a no-brake model. If an application requires the axis to remain mechanically held after servo power is removed, an appropriate external holding solution may be required.

4. What type of shaft does the RK72AA have?
The model uses a keyless shaft extension. The mating coupling should be specifically suitable for a keyless servo motor shaft and installed with the manufacturer's specified clamping procedure.

5. Can the RK72AA directly replace an MPL motor with an absolute encoder?
Not necessarily. The RK72AA uses resolver feedback, while an absolute-feedback motor uses a different feedback architecture. The servo drive and motion controller must support the resolver configuration.

6. What voltage is the MPL-B310P-RK72AA designed for?
The motor is specified for a 460 V AC armature voltage and belongs to the 400 V class of MP-Series MPL servo motors.

7. What should be checked if the servo drive reports a resolver fault?
Check resolver wiring, connector seating, feedback cable condition, shielding, grounding, and the drive's feedback configuration. Damaged cables and excessive electrical interference can also cause intermittent feedback problems.

8. How should the keyless shaft be connected to the machine?
Use a compatible coupling or clamping hub designed for the shaft configuration. Proper shaft alignment, insertion depth, clamping torque, and mechanical balance are important for reliable high-speed operation.

9. What can cause unstable servo operation after installation?
Possible causes include incorrect feedback configuration, unsuitable servo tuning, mechanical resonance, excessive load inertia, coupling misalignment, or incorrect motor parameters. Both drive diagnostics and mechanical inspection should be used during troubleshooting.

10. What maintenance does this servo motor require?
Inspect the mounting hardware, shaft coupling, motor connectors, resolver cable, and power connections regularly. Monitor temperature, vibration, noise, and changes in positioning performance. Prevent cable damage and excessive contamination around the motor and connector areas.

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