Automation's evolving uses for motors and drives

As automation continues to expand in existing as well as newer applications, the enabling automation technology is evolving to keep pace with these changes. Motors and drives are no exception. In particular, motors have gotten smaller to accommodate space and size restrictions in new, unique applications. There have also been changes to how motors are designed and built, with an increase in custom designs as well as motor and drive networking and connectivity.

We recently asked several leading industry experts about trends they’re seeing in motor, gearmotor, and drive technologies. Here’s what those experts had to say.

Meet the experts

Biren Patel | Business development manager, mobility solutions · maxon

Chris Gottlieb | Director, drives, and control · Kollmorgen

Dave Beckstoffer | Business development manager · Portescap

James Gallant |Director of operations · ISL Products International Ltd.

Lawrence Lin | EV batteries business development manager · Festo

Robert Luchars | Vice president for business development · ECM PCB Stator Technology

How is it that motor manufacturers can build motors of sizes impossible just a decade ago?

Beckstoffer: The miniaturization of motors over recent years has been accomplished by several key factors — design, materials, and automation capability. From a design perspective, advances in simulation software provide engineers with the capability to evaluate smaller-diameter concepts to confirm feasibility. Engineers also continue to push the boundaries of size reduction through unique and patented motor features. This is further enabled by advances in materials, including higher power magnets, more conductive metals, and higher strength components.

All of this requires automation to precisely wind coils and complete the assembly of the miniature components of the motors. With the continual advances in these areas, motor manufacturers have been able to design and produce motors with continually smaller diameters and lengths.

Gallant: Brushless motors have become much more widely accepted and used over the past few years. Along with that, the development cost has dropped significantly, making them more affordable. We can offer brushless motors with planetary gearboxes as small as 22 mm in diameter. Brushless motors, by design are a little more susceptible to the elements with a better IP rating. We get about 50% of our new-customer requests for brushless motors vs. brushed motors.

Our gearmotors can be found in almost any commercial or industrial application ranging from white goods to robotics to hunting equipment. We offer either planetary, spur, or worm gearboxes on our dc motors. Our motors are either brushed or brushless and coreless options are also available. Our planetary gearmotors can be as small as 12 mm in diameter, and worm gearmotors can get up to over 70 mm in diameter.

Festo CMMT-ST servo drives are mounted on the robot itself rather than on the gripper
system, freeing up space on the gripper and making the design less complicated.

Beckstoffer: Brushless dc (BLDC) motors provide operational advantages with their high-speed capability and electronic commutation. In addition, a slotless BLDC design enables rapid acceleration and deceleration due to the self-supporting cylindrical coil design. Short-term circulatory support devices assist the patient’s heart during a cardiac event or surgery, supplementing the pumping of blood throughout the body. The device needs to operate at high speed and be supremely responsive to the sinus rhythm of the heart, making BLDC slotless motors an ideal solution. The high-power density of these motors also ensures sufficient torque is available to respond to any changes in the patient’s condition.

Luchars: Customers typically come to ECM intending to remove gears from their design, as the geartrains in motor systems typically add size, cost, complexity, and noise to the system. Our partners are instead interested in a direct-drive solution. ECM is capable of running the direct drive analysis (in addition to a variety of gear ratio designs) to explore the cost, size, and weight tradeoff of each. Because we can execute rapid analysis of various gear systems, the optimal speed-torque combination can be quickly determined with high certainty. This lets us design suitable motor-geartrain-system combinations.

What are some new and unique motor applications you’ve recently supported?

Patel: maxon has released a new family of frameless motors designed specifically with dynamic movements in mind. The DT series (Dynamic Torque) can be easily integrated into a wide range of applications, specifically when it comes to applications where speed can change instantly. The rotor and stator are delivered separately, without bearings or motor shaft, and are connected only during assembly. The features of the EC frameless DT motor series include minimal rotor inertia, excellent heat dissipation, compactness, and extremely simple integration. The flat design, high torques, and space for cable glands allow a high level of integration into a given application.

Gottlieb: Regarding design-based improvements, concentration on flux optimization produces motors such as the Kollmorgen AKM2G, which packs a punch of torque density and higher power in the same package as older generations of servomotors. Or consider the coming release of our AKMA washdown servomotor. It really is solving the problem of the food-grade paint motor being unacceptable in a food environment as the paint may peel but it is much more economical than the sanitary requirement level of the AKMH hygienic motor. It will hit a real sweet spot.

Luchars: Regarding washdown or corrosive settings, ECM can fully enclose its motors, while keeping them cool, due to the patented qualities of our stators. PCB Stators use both the inactive and active copper in the PCB stator to conduct heat out through the aluminum housing, rather than requiring air to be drawn or blown through the stator windings‚ as occurs in a traditional wire-wound machine. This is beneficial as it radically improves the sealing and protection of the internal motor components to limit the ingress of other foreign objects, debris, or harmful fluids.

Lin: EV battery manufacturers respond to the fact that Festo built its EMMT stepper motors and compact CMMT servo drives for interoperability in complex motion systems. The CMMT drives are compatible with all major Ethernet-based communications protocols for wide applicability. The EMMT/CMMT combination is ideal for producing the speed, torque, and accuracy required in gantries. Festo also provides mechanical axes for a one-stop shop of interoperable products.

Luchars: Most brushed motor applications we have seen have been for cost-sensitive consumer goods. These, of course, have increased wear and decreased efficiency, but they are simple and cost-competitive. ECM can quickly use our software design platform, PrintStator, to understand whether a PCB Stator offering would be cost competitive. This saves a lot of time and resources that might end up being dedicated to a given project, only to later determine that the technology isn’t a good fit. If a PCB Stator machine is cost competitive, all the drawbacks of a typical brushed machine would be eliminated with a PCB Stator machine. ECM can design various motors, from constant-speed HVAC fans and blowers, to torque motors with resolution and torque requirements. This is another easy task from a modeling perspective to see how the torque production of an ECM machine compares to that of a traditional servo or stepper.

This exploded view shows an ECM motor with a PCB stator used in a handwheel controller for camera control.

For the last few years, ECM has taken customer specs for various electric motor applications so our in-house engineers and beta partners could use PrintStator to model, protoype, and produce design solutions. We’ve also formed partnerships with production houses for clients without manufacturing capabilities. We see this model as a means to extend next-generation motor capabilities to existing motor suppliers and any vertical that requires electric machines. PrintStator-designed stators can be printed anywhere in the world‚ so, in essence, we’re allowing our SaaS partners to become their own motor OEMs.

We’re also actively engaged in electric motor design collaborations with companies such as Celestica, a multi-national electronics manufacturer, and will announce several new partnerships with large global manufacturers in 2023. Offering PrintStator via a full SaaS product will extend the benefits of PCB Stator electric motor design to multiple innovators to create custom innovations in numerous verticals. These include applications for blue-chip corporations, governments, small businesses, gaming companies, innovators, disruptors, and startups‚ to name a handful.

In what ways have you assumed customization and systems as a service (SaaS) design work for machine builders?

Gallant: We help machine builders at the component level in dc motors/gearmotors. Working with a motor specialist like ISL Products helps OEMs streamline that aspect by relying on experts rather than searching the internet for a possible solution. ISL designs and manufactures dc motors/gearmotors to customer specs by tailoring our standard designs. We consider this process as a value-added service to all of our customers while offering competitive pricing.

Luchars: ECM’s mission is extending software to innovators and engineers to meet future requirements for highly specialized electric motors. By one estimate, demand for electric motors will surge to over a billion units a year across nearly every imaginable vertical in a sector valued at well over $200 billion annually. Initially, this may sound like a hardware challenge. Ultimately, we have concluded that SaaS design is vital to meeting next-generation motor needs. That lies fundamentally in an assessment that what’s worked in the past with electric motor design won’t deliver moving forward. There are three factors shaping the need for a more specialized approach.

An obvious catalyst is the conversion of many of these categories‚ such as mobility and heating‚ from fossil fuels to electric energy. An additional driver is the surge of robotics and automation across multiple sectors. And a third factor spurring global electric motor need is the push to convert more of our energy to electricity.

We’ve done internal research to determine what kind of machines will best serve this electrified future. A predominant conclusion: the world won’t simply need more electric motors. Global markets will require next-generation electric motors that are more efficient, better performing, bespoke, and produced more sustainably. To create those machines, OEMs and plant engineers will require better designs. In ECM’s experience, the best way to achieve those designs is to offer them the performance and sustainability benefits of PCB Stator electric motors through software as a service. Our PrintStator SaaS platform allows engineers to create their own PCB Stator electric motors, designed to precise performance and form factor specifications. ECM is currently beta-testing PrintStator with plans for a full SaaS release in 2023.

An ECM employee holds a conventional copper wound stator (on the left) and an ECM PCB Stator (on the right) for comparison.

What recent trends are you seeing in motor and drive connectivity?

Gottlieb: Safety over EtherCAT allows for simplicity in installation, and the drive-to-motor monitoring is fast — you don’t have to wait for controller monitoring. One of the most basic applications where I’ve seen safety work is where packaging blanks are added into a hopper while the machine is running. The blanks are held in an interlocked section of the machine, but you can open the blank box’s interlock handles at slow machine output speeds, allowing the machine to keep running while feeding it. This avoids the shutdown and the subsequent startup cycle — of which there are no guarantees that the restart would go smoothly.

Also, safety drives are a ‘must have’ in the marketplace. Advanced safety functions allow improved human productivity and improved statistical safety for human interaction while the machine is running or if the machine is stopped. Safe Torque Off on a drive is now ‘table stakes,’ and where machine builders can differentiate is in the advanced safety options allowing for safe speed, safe stop, safe direction, and more. We offer sixteen different safety functions in our SafeMotion Monitor so that the OEM can choose the methodology that works for them.

Luchars: ECM can incorporate any cable connection; we have done this on several occasions, depending on what the customer requires for the application.

ECM’s patented process replaces the stator copper wiring in a conventional motor with a printed circuit board, allowing for extremely thin motor designs, as shown here.

Gallant: Over the years, we have helped many customers by providing them with value-added motor solutions. This comes down to adding slight customization to the motors to help streamline the customer’s assembly process. One of the more common requests is to add lead wires to the motor terminals. Some customers request that a specific connector be added as well — from common brands such as Molex, TE, JST, and others.

This is a simple request for our manufacturing team, allowing our customers a quicker install on their assembly line. It’s a service we are happy to offer.

Gottlieb: I think you’re seeing the requirement for flexibility in cable connections from a supply chain perspective. We need to make sure that there is interoperability between connectors from different vendors during these times of precarious supply chains.