The Development of the Axial Integral Horsepower Motor

Traditional radial and external rotor motors in the marketplace today inherently present manufacturers with some constraints: e.g., size, weight and the need to stock many designs to meet different customer specifications. Within Regal, two teams — 11,000 miles apart — became one to concentrate on refinements to the company’s air-moving motor technology. This ultimately led to break-through concepts in design, which enabled commercial air-handling manufacturers to think differently.

After two years of development, the company has introduced a new motor concept: the axial integral horsepower motor. For equipment manufacturers, it offers a completely new path and platform for innovation and performance with game-changing implications for the commercial air handling equipment industry in terms of motor size, weight, design, intelligence and functionality across a range of power ratings.

Parallel innovations
In North America, a Regal innovation team was working on enhancing the air moving efficiency of electrically commutated radial permanent magnet motors (ECM), leveraging the variable speed capability, higher torque and higher reliability inherent in the permanent magnet design. The team was exploring software controls that could both maximize motor efficiency while expanding its variable speed capabilities, enabling HVAC manufacturers to do more with fewer motors.

Simultaneously, a Regal team in Australia was studying a different motor concept that could potentially allow manufacturers to do more with radically smaller motors. For example, in an axial motor, the magnetic field runs parallel to the typical shaft output location, rather than radially through the rotor and stator. As a result, axial motors can be far thinner and lighter. Their lightweight design makes them ideal for applications where
quick changes are required. But there were major obstacles for any commercial application of the novel motor technology, particularly for air moving and thermal applications. Could the design be made robust and reliable enough for heavy-duty, commercial use — particularly the demands of HVAC systems? If so, at up to one-third the length, one-third the weight, and with a lower power demand than conventional induction motors, the commercial potential of viable axial flux motors was limitless.

Swapping solutions
In 2015, the innovation team compared notes and realized that their research was scalable. The work on the radial ECM motors, particularly in the variable speed software control, was easily applied to the axial flux motor concept. With integrated variable speed control software and a new plenum fan design, the axial motor could move the same amount of air at lower horsepower. The key was changing the cross-shaped axial flux motor to an orbital design. This optimized air movement without obstructing air flow within the narrow air gap — a design change that also simplified the implementation of electronics and controls within the small footprint, a key to high output from a significantly more compact, easily mountable motor.

A completely new machine in form and function
With Regal axial integral horsepower motors, manufacturers have a completely new way to look at the design of HVAC and other thermal air moving systems. Across the board — in reduced size, simplified manufacturing and versatile motor performance — manufacturers have a new set of design considerations, all with significant implications toward reducing costs and improving performance.

First consideration: size and weight. Equipment manufacturers have always been limited to radial induction motors; there are few if any alternatives in the marketplace. Thus, the motors are inherently large, bulky and heavy, and, to a large degree, systems must be designed to accommodate the motor. With axial integral horsepower motors, this design consideration changes completely. The door is open for significant optimization.

Understanding the significance form factor has to manufacturers and customers, the axial integral horsepower motor has been designed to reduce the length to approximately four and a half inches, compared to the 14 to 16 inches currently in standard radial motors. With the compact, flat design, there is no longer a need to design around the motor, and the motor can be intentionally hidden inside a much smaller system.

The weight savings are equally dramatic: more than 66 percent lighter than conventional radial motors. The lower weight, combined with the potential for much
smaller overall systems packages, can fundamentally change the way systems are installed at an end user’s facilities, often eliminating the need for heavy installation equipment and weight-bearing mounting systems. Cranes are out; hand trucks are in.

Three motors: one complete inventory
Another consideration: manufacturing. Today, HVAC manufacturers maintain an average of eight motor SKUs to meet the power requirements of different applications. Regal’s three variable speed axial horsepower motors —3 to 15 HP — provide the output to cut the average motor inventory in half.

The key is configurability. Axial integral horsepower motors allow for speed and horsepower configurations to cover a wide range of specifications while still optimizing system efficiency. They’re variable speed, and due to their integrated software, easily configured on-site. By reducing the number of SKUs, manufacturers can lower their inventory costs by turning to three far smaller motors, alone or in combination. With their slotted mounting systems, installing and configuring the axial horsepower motors is simple: the motors drop right in. Given the light weight, there’s no longer a need for a motor support base, eliminating another manufacturing cost.

No compromises
Another consideration: performance. With axial integral horsepower motors, selecting the right fan for the job can come down to one motor. Regal® motors are inherently tailored to a customer’s applications. A 10 HP, 1,800 RPM motor can be reconfigured to the rating required by the application and the multiple fans used, with the ability to limit the current on the fly. With direct power transfer, variable torque at power up, and integrated intelligent and modular controls, the axial integral horsepower motor is designed to optimize total integrated system performance and efficiency. Within the 3–15 HP range, the motors can scale to any specification.

This scalability means the motor can be set up and tuned to a customer’s specifications at the end of the line: systems do not have to be built around their motors. This turns the supply chain upside down: configuring the motors to system requirements is a final step, not the first design decision.

The motors are smaller, but their design capitalizes on the superior reliability inherent in permanent magnet motor technology. A metal film capacitator allows the motors to run at higher temperatures more reliably than motors with electric capacitors.

Lower cost of ownership
Long-term cost savings accrue from every aspect of motor performance. The smaller, lightweight design means far less metal, and the fewer number of SKUs means less to buy and store. This also translates into simplifying or eliminating manufacturing processes. Smaller enclosures will mean lower installation costs. Even the simplified wiring and orbital software configuration contribute high reliability and an overall lower cost of ownership. Adding to the lower costs: the flexibility to use fan wheels from any supplier, eliminating the costs associated with purchasing a full assembly. Serviceability is another cost-cutting factor. Modular electronics, accessible mounting and the capability to fine-tune motor power in the field means one technician can handle it, with less time and labor.

Powering the future
Considering that much smaller, lighter and flexible motor technology could have enormous implications for HVAC and OEMs, the team pushed the first commercial application for the axial integral horsepower motor toward that INDUSTRY. Thermal is hard. Creating a game-changing motor for those systems is proof of concept for Regal’s axial integral horsepower motor advances. And the concept has the potential to be introduced into new areas where size, weight, performance, reliability and configurability are equally critical. Today, Regal design teams are working on further innovations to the axial platform, adding more power and robustness to the design to address needs in pumping and general industries.

About Regal Beloit Corporation
Regal Beloit Corporation (NYSE: RBC) is a leading manufacturer of electric motors, electrical motion controls, power generation and power transmission products serving markets throughout the world. The company is comprised of three business segments: Commercial and Industrial Systems, Climate Solutions and Power Transmission Solutions. Regal is headquartered in Beloit, Wisconsin, and has manufacturing, sales and service facilities throughout the United States, Canada, Latin America, Europe and Asia. For more information, visit