Introduction

The Allen-Bradley MPL-B320P-RK72AA Servo Motor is part of the Allen-Bradley MP-Series MPL family of low-inertia brushless servo motors. It is configured for 480 VAC-class industrial motion systems and combines a 100 mm frame with a 50.8 mm magnet stack and a 5000 RPM speed rating.

The MPL-B320P-RK72AA is particularly distinguished by its resolver feedback, keyless shaft, and no-brake configuration. These characteristics make it different from several closely related MPL-B320P models that use keyed shafts, high-resolution encoders, or integrated 24 V DC brakes.

The motor provides approximately 3.05 Nm of continuous torque and is intended for applications where controlled acceleration, deceleration, velocity, and position are required. When paired with a compatible Allen-Bradley servo drive and motion controller, it can form part of a complete closed-loop motion-control system.

The right-angle SpeedTEC DIN connector is another practical feature for machine builders. Because the connector can be rotated, cable routing can be adapted to the available space around the motor. This is useful in machines where motor installation space is restricted or where cable routing needs to avoid moving mechanisms.

The keyless shaft configuration should also be considered during mechanical design. The coupling, shaft interface, alignment, and permissible mechanical loads should be selected according to the motor and machine requirements. Proper alignment is important because excessive radial or axial loading can shorten bearing life and negatively affect servo performance.

For replacement applications, the complete catalog number should always be checked before installation. The MPL-B320P family contains versions with different feedback technologies, shaft configurations, and brake options. A visually similar motor is not necessarily a direct electrical or mechanical replacement.

Technical Specifications

Parameter	Specification
Brand	Allen-Bradley
Product Family	MP-Series MPL
Product Type	Rotary Servo Motor
Model	MPL-B320P-RK72AA
Motor Type	Low-Inertia Brushless Servo Motor
Voltage Class	480 VAC
Armature Voltage	460 V
Frame Size	100 mm / Frame 3
Magnet Stack Length	50.8 mm (2.0 in.)
Rated Speed	5000 RPM
Continuous Torque	Approx. 3.05 Nm
Rated Output	Approx. 1.5 kW
Feedback	2-Pole Resolver
Shaft Configuration	Keyless Shaft Extension
Brake	No Brake
Connector	SpeedTEC DIN Right-Angle Connector
Connector Rotation	180° Rotatable
Mounting	IEC Metric
Mounting Holes	Free Mounting Holes, Type FF
Servo Construction	Low-Inertia Brushless
Dimensions	Not specified in the supplied product data
Weight	3.70 kg (8.16 lb)
Lifecycle	Active Mature

Recommended Related Models

The following MPL-B320P models are useful when comparing different feedback, shaft, and brake configurations:

MPL-B320P-RJ72AA – Resolver feedback, keyed shaft, no brake
MPL-B320P-RJ74AA – Resolver feedback, keyed shaft, 24 V DC brake
MPL-B320P-RK74AA – Resolver feedback, keyless shaft, 24 V DC brake
MPL-B320P-MK72AA – Multi-turn high-resolution feedback, keyless shaft, no brake
MPL-B320P-MK74AA – Multi-turn high-resolution feedback, keyless shaft, 24 V DC brake
MPL-B320P-MJ72AA – Multi-turn high-resolution feedback, keyed shaft, no brake
MPL-B320P-MJ74AA – Multi-turn high-resolution feedback, keyed shaft, 24 V DC brake
MPL-B320P-SJ72AA – Single-turn high-resolution feedback, keyed shaft, no brake
MPL-B320P-SJ74AA – Single-turn high-resolution feedback, keyed shaft, 24 V DC brake

These models belong to the same general MPL-B320P platform but should not be treated as electrically interchangeable without checking the servo drive, feedback interface, shaft arrangement, brake requirements, and machine configuration.

Popular Related Models

For applications using Allen-Bradley MP-Series MPL servo motors, the following models are commonly considered alongside the MPL-B320P-RK72AA:

Allen-Bradley MPL-B320P-RJ72AA – 480V AC rotary servo motor with resolver feedback and keyed shaft
Allen-Bradley MPL-B320P-RJ74AA – 480V AC rotary servo motor with resolver feedback and brake
Allen-Bradley MPL-B320P-RK74AA – 480V AC rotary servo motor with resolver feedback, keyless shaft, and brake
Allen-Bradley MPL-B320P-MK72AA – Multi-turn absolute feedback, keyless shaft, no brake
Allen-Bradley MPL-B320P-MK74AA – Multi-turn absolute feedback, keyless shaft, and brake
Allen-Bradley MPL-B320P-MJ74AA – Multi-turn absolute feedback, keyed shaft, and brake
Allen-Bradley MPL-B320P-SJ74AA – Single-turn high-resolution feedback, keyed shaft, and brake
Allen-Bradley MPL-B320P-SJ72AA – Single-turn high-resolution feedback, keyed shaft, no brake

When selecting a replacement for the MPL-B320P-RK72AA, pay particular attention to the resolver feedback, keyless shaft, 5000 RPM rating, 460 VAC armature voltage, frame size, magnet stack length, and brake configuration. These parameters determine whether another MPL motor is an appropriate replacement for the existing machine.

Applications

The Allen-Bradley MPL-B320P-RK72AA is suitable for industrial motion systems where accurate speed, torque, and position control are required. Its low-inertia construction helps servo systems respond quickly to acceleration and deceleration commands.

Typical applications include:

CNC machine tools and machining equipment
Packaging and filling machinery
Printing and converting machines
Material handling systems
Pick-and-place equipment
Automated assembly machines
Semiconductor and electronics manufacturing equipment
Robotics and precision positioning systems
Web handling and winding equipment
High-speed indexing machines
Industrial automation production lines
Servo-driven conveyor systems

The 5000 RPM speed rating makes the MPL-B320P-RK72AA suitable for applications requiring relatively high rotational speed while maintaining controlled motion. The resolver feedback system provides the servo drive with motor position information for closed-loop control.

Because this model uses a keyless shaft extension, it can be integrated into applications where the mechanical coupling and shaft-hub arrangement are designed specifically for a keyless connection.

Advantages

Low-inertia servo design

The MPL-B320P-RK72AA belongs to the MP-Series MPL low-inertia servo motor family. Low rotor inertia helps reduce the energy required to accelerate and decelerate the motor, which can improve dynamic response in repetitive motion applications.

5000 RPM operating capability

With a rated speed of up to 5000 RPM, the motor can support high-speed positioning, indexing, and rotary motion applications.

460 VAC armature voltage

The motor is designed around the 460 VAC class used with compatible Allen-Bradley motion control systems, making it appropriate for industrial machine architectures using higher-voltage servo power.

Resolver feedback

The two-pole resolver provides motor feedback for closed-loop servo control. Resolver-based feedback can be advantageous in industrial environments where robust position sensing is important.

Keyless shaft extension

Unlike keyed-shaft variants, the RK72AA uses a keyless shaft configuration. This can simplify certain mechanical coupling arrangements and allows machine builders to select a coupling system appropriate for the application.

Right-angle rotatable connector

The SpeedTEC DIN right-angle connector can be rotated, helping engineers route motor cables more effectively in compact machine layouts.

IEC metric mounting

The motor uses IEC metric mounting with free mounting holes, making it suitable for integration into machine frames and mechanical assemblies designed around metric dimensions.

No integrated brake

The absence of a brake provides a straightforward motor configuration for applications where an external mechanical holding mechanism is unnecessary or where the machine uses another method for load holding.

Technical FAQs

1. What type of servo motor is the Allen-Bradley MPL-B320P-RK72AA?

It is an MP-Series MPL 480V AC rotary servo motor using a low-inertia brushless motor design. It is intended for closed-loop industrial motion-control applications.

2. What is the frame size of the MPL-B320P-RK72AA?

The motor has a 100 mm frame size, corresponding to Frame 3 in the MPL-B320P product configuration.

3. What is the rated speed of the MPL-B320P-RK72AA?

The specified maximum/rated motor speed is 5000 RPM.

4. What feedback device does this servo motor use?

The MPL-B320P-RK72AA uses a 2-pole resolver for motor feedback. The resolver provides position information required by the servo control system for closed-loop operation.

5. Does the MPL-B320P-RK72AA have a brake?

No. The RK72AA configuration does not include a motor holding brake.

6. What type of shaft does the MPL-B320P-RK72AA use?

This model uses a keyless shaft extension. It should therefore be matched with a compatible mechanical coupling rather than assuming a keyed coupling arrangement.

7. What voltage is the MPL-B320P-RK72AA designed for?

The motor is specified with a 460 V armature voltage and belongs to the MP-Series MPL 480V AC servo motor family.

8. What is the magnet stack length?

The MPL-B320P-RK72AA has a 50.8 mm (2.0 in.) magnet stack length.

9. What is the continuous torque rating of the motor?

The motor has a nominal continuous torque rating of approximately 3.05 Nm under the specified operating conditions.

10. What is the weight of the MPL-B320P-RK72AA?

Based on the supplied product data, the shipping/product weight is 3.70 kg (8.16 lb). Actual shipping weight can vary depending on packaging and accessories.

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