I have a friend in the industry who gets upset when someone tells him “My AC motor quit running right”. His response is always something like, “It’s not the motor. The motor is dumb. If you apply the proper power and if there’s no issues on the load side, it’s gonna do what it’s supposed to do or not run at all”. Which is essentially true. Sorry motors, but your just not all that smart. Except maybe DC and servo motors. Even with those though, the brains are mostly in the drive controls.
Could an AC motor be made smart? You could argue that by applying a VF drive it’s now smart. It will speed up and slow down on demand. But those are normally mounted several feet away or even in the next room so not an integral part of the motor. Not that it couldn’t be mounted in an oversized junction box but why do that? Drives are typically electronic devices and prefer a nice comfy control room environment away from the heat, vibration and contamination that those dumb old workhorse motors live in. It could be done though. Who knows, maybe someone is already doing it.
Okay, so our motor can speed up and slow down by itself, now let’s imagine it’s smarter yet. It senses incoming current and controls start up torque very slowly to avoid stressing its copper muscles and insulation ligaments. No mechanical stresses from the winding flexing in this smart guy. And once up to full output, current and voltage are sensed and kept in near perfect balance through an integral variac or some other new technology. This is all already doable and being done in a few cases but external to the motor with surge suppressors, chokes, variacs, soft starts, etc.
Now let’s look at the smart mechanical features. Ultrasonic sensors could tell the motors brain its bearings are needing a fresh squeeze of lube and it’s automatically added. In fact, let’s get smarter yet and measure the bearings operating temperature and have it add an appropriate rated compatible grease for the current operating conditions. The ultrasonic sensors would also detect when just the right amount of grease has been added.
Of course, our smart motor also protects itself from outside contamination with mechanical seals on both ends. Stray shaft currents are mitigated with insulated ceramic coated bearing housings and integral grounding devices. And the cooling system is thermostatically controlled with high speed fans and high surface area fins to quickly dissipate the heat and keep the temperature just right regardless of the motors operating speed. This will also improve efficiency by eliminating the drag caused by the cooling fans rotation when it’s not needed to run continuously.
Yeah that’s all well and good you say but what if the motor wasn’t installed properly and there a misalignment issue? That’s where the integral “SmartBase” comes into the picture. With pressure sensors on the bearings the motor automatically adjusts itself with a series of tiny electric jack screws to maintain perfect alignment and load balance on the shaft.
But let’s not forget external communication and the industrial internet of things. If the smart motor needs a human to intervene when it’s systems fail or aren’t enough to self-correct it calls or texts you and asks for your help. Not just a generic call for help but something like, “I’m sensing pressure on the right side of my drive end bearing and can’t seem to correct it. I’ve run my diagnostics and it seems the drive side horizontal jack screw is non-responsive”.
Or maybe the request for human intervention is just for a simple task like replacing a lube cylinder. Then the call might go something like, “I’ve just dispensed the last of my high temperature grease. Please replace in the next 10 days before my next lube cycle”. Maybe despite all of the smart features in this motor it still needs an occasional recondition. It could alert you to this fact and send notifications to production and the plant manager predicting when the bearings will fail and start damaging the motor if not shut down and removed. It could even notify the repair shop what parts will be needed and when the motor will be available to be sent in.
Although some of this is probably impractical, as the cost of sensors comes down and new products are brought to market who knows how smart our dumb friend will become.