This article introduces the key innovations of the powerful AZX Series, which is a uniquely different servo motor and driver system designed to be easier to use and more cost-effective than traditional servo motor systems.
What's covered?
As someone who has spent years sizing stepper motors for various applications across industries, I understand the need for speed. Since more throughput increases production efficiency, faster is always better. When dealing with large inertial loads, long strokes, or quick acceleration/deceleration ramps, it could be challenging to find a stepper motor to do the job. This is a limitation for hybrid stepper motors; even for our high performance AlphaSTEP closed-loop AZ Series Step-Servo motors.
By combining proven mechanical absolute encoder (ABZO sensor) technology from the AZ Series with SPM (Surface Permanent Magnet) technology, the AZX Series servo motors are able to output more torque and more speed while offering the same ease-of-use benefits. Whether you're upgrading existing equipment or designing new systems, understanding this technology could be the key to meeting your unmet requirements.
AZX Series Servo Motor and Driver
Higher Torque and Higher Speed Characteristics
For the AZX Series, we wanted to generate more high speed torque than the AZ Series, so we pivoted from the hybrid stepper motor design to an SPM (Suface Permanent Magnet) design. In an SPM design, permanent magnets are also attached to the surface of the rotor. By making this design change, we were able to output up to 3x maximum instantaneous torqu compared to rated torque and maintain consistent torque output from low to a higher speed range (up to 5,500 RPM). This enables rapid acceleration and deceleration and presents significant reduction in positioning time even for long distance moves.
Compared to the existing AlphaSTEP AZ Series Step-Servo motors, the speed-torque performance of the AZX Series offers higher max RPM and much more maximum instantaneous torque in the limited duty region. This maximum instantaneous torque can be used to accelerate or decelerate the load faster.
If we compared the shortest positioning time between the most powerful AZ Series motor [AZM911AC] vs the AZX Series [AZXM960AC], the AZX Series motor can position the same load 0.325 seconds faster. While that doesn't seem like a lot of time, it adds up.
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Operating Conditions: Load inertia = 7.86 × 10-4 kg•m² Travel distance = 500 mm (Number of Motor Revolutions: 20) Maximum operating speed = 1250 mm/s (Motor Speed: 3000 r/min) Ball Screw Lead: 25 mm |
Proven Battery-Free Mechanical Absolute Encoder Technology
Unlike an optical absolute encoder, which requires an LED to produce light pulses through a wheel with slits, a mechanical absolute encoder is much simpler in design, more robust, and less expensive to manufacture. It operates by sensing the positions of permanent magnets on multiple disks, so no battery is required. Typical costs associated with an optical absolute encoder are eliminated, such as the battery, cables, external sensors, and the maintenance that is required, making the AZX Series more competitively priced than traditional servo motor and driver systems.
The integration of the mechanical absolute encoder to a servo motor brings several functional advantages from the AZ Series, such as multi-turn absolute position control, being able to operate in harsher environments, instantly resume operation after power failure without homing, wrap/proximity positioning, and fast sensorless homing cycles. However, the mechanical absolute encoder does have a limitation of 1,800 rotations max and lower resolution than optical encoders. Unless you're continuously moving for a long time or need to be ultra-precise, these limitations should not affect most applications.
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Challenge: Thermal Design Improvements
One of the most impressive aspects of the AZX Series is its sophisticated thermal management system. As someone who has dealt with countless motor failure cases due to thermal issues, I can appreciate the engineering that went into this design. The existing AZ Series could not reach higher RPM due to too much heat generated by the iron loss of the motor. The heat could exceed the upper limit for the mechanical absolute sensor. For the AZX Series, we switched to an SPM (Surface Permanent Magnet) motor design to reduce heat generated for high speed operation. The AZX Series also integrates a heat dissipation sheet with higher thermal conductivity than air between the mechanical absolute encoder and the aluminum sensor cover, which efficiently conducts the heat the mechanical absolute encoder receives from the motor to the sensor cover. The installation of the heat insulation plate between the sensor cover and the motor (heat source), suppresses the temperature rise of the sensor cover and efficiently releases the heat.
The result is a 10° C reduction in the operating temperature of the mechanical absolute encoder, which maintains performance even at higher ambient temperatures and extended service life through better thermal management.
Higher output power also increases heat generation in power components, including the driver's inverter circuit. Therefore, to achieve high speed operation, the power components and control components needed to be separated. The AZX Series driver has the power components installed on the rear side and the control components installed on the front side. The built-in cooling fan forces ventilation cooling on the power components, and the heat exits through the top ventilation slits. This prevents the heat generated by the power components from affecting the control components.
The result is higher ambient temperature tolerance, improved reliability in dense installation environments, and reduced thermal stress on critical components. The image below compares the temperature distribution with different output powers (70% vs 100%). The improved heat dissipation structure reduces heat for heat-sensitive control components and ensures the same maximum operating ambient temperature of 55° C even with increased output power.
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Same Operability as the AZ Series
While the performance characteristics are different, the control architecture of the AZX Series driver offers the same operability as the AZ Series, such as signal wiring, parameter functions, parameter IDs, and positioning functions. If you have used an AZ Series driver, then there's no learning curve.
The AZX Series is compatible with 3 major industrial communication protocols: EtherNet/IP™, EtherCAT®, and PROFINET. Minimize wiring and enable more control by controlling or monitoring your motor via network commands.
In addition, the AZX Series includes several sophisticated features that simplifies implementation:
The MEXE02 software used by the AZX Series is intuitive and easy to use. Up to 256 unique stored motion profiles can be programmed easily and linked in many different ways (more is possible through direct-data operation via network command).
Something like this would be a simple sequence function that can be programmed in minutes.
The AZX Series represents a significant advancement in motor technology, particularly in addressing the long-standing challenges of high-speed, high-torque applications. This series offers substantial improvements in performance while offering the same functionalities as the AZ Series. The combination of improved thermal management, advanced control capabilities, and simplified integration makes the AZX Series a compelling choice for various industrial applications, such as packaging, assembly, material handling as well as precise applications like semiconductors, medical devices and labortory automation.
For the AZX Series, currently we offer 2 wattage models: 400 W (1/2 HP) and 600 W (4/5 HP) in either round-shaft (ungeared) or planetary geared types. An optional pre-assembled electromagnetic brake is available for vertical operations where loads need to be held when powered off. For round-shaft motors, rated torque ranges from 180 oz-in to 270 oz-in, and maximum instantaneous torque ranges from 540 oz-in to 1,020 oz-in. For geared motors, the rated torque ranges from 50 lb-in to 370 lb-in, and maximum instantaneous torque can be as much as 1,400 lb-in. Both position and speed control modes are available on the AZX Series. For advanced modes, such as tension control, please refer to our NX Series.
As manufacturing continues to evolve toward higher speeds and greater precision, technologies like the AZX Series will become increasingly important. The integration of advanced features while maintaining compatibility with existing systems positions this technology well for future adoption and expansion.
For engineers and system integrators looking to increase production throughput, improve precision in automated processes, or optimize their automation systems, the AZX Series provides a robust solution that addresses many common challenges while offering room for future growth and adaptation.
For help with motor sizing or selection, please contact our helpful technical support engineers.