5 becomes 25

In an effort to simplify the presentation of the hybrid machine motor styles to make them easier to understand, I skipped over a number of possible variants. I hoped by focusing on just a few styles the attention of the audience would not get spread too thin to make sense of the body of them. However, since so many of the people looking into this material are in academia, research organizations, and in related industries, I feel its safe to delve deeper into the subject.

I’ve shown how we can make 5 different styles of motors using the same core components: Stepper, synchronous, three phase, and two others that have not yet been publicly disclosed.This was an overly narrow claim.

To broaden the 5 motor style claim we can divide the stepper style motor into bipolar stepper and unipolar stepper, which are two different ways of driving a stepper motor, each having distinct advantages. We could also add universal stepper which consists of providing the wiring to make connections to drive a stepper using either the bipolar drive scheme, or the unipolar drive scheme. If we go for bragging rights we would say we can make three different styles of stepper motors using the same core components; bipolar, unipolar and universal. Thus, one stepper style of motor becomes three.

5 Becomes 25

Next let’s take a look at the synchronous style motor: Being these are permanent magnet motors and that they are also axial flux motors, they have high starting torque. This also means we can drive them in non-conventional ways. For example: synchronous motors are designed to just follow the wave form of the AC current available at the wall outlet. However, if we were to invert a DC source we can control the frequency of the AC entering the motor. With proper control circuitry we can create a variable speed AC motor with high starting torque.

Further exploration of the synchronous style motor being driven with an inverted DC power supply shows that because of the high torque we can run the motor very slowly and even stop and start it, stepping it forward incrementally like a stepper motor.

If we rewire the synchronous motor coils and control the current going into them independently, with schemes other than what the synchronous style normally calls for, we can even drive the motor forward and backward, stepper style or otherwise.

The above three variants of the synchronous style motor could even be applied in a single application. For example: A pump could be run synchronously in normal operation, and could also be slowed down or sped up to vary the flow rate, and it could also be driven step-wise to serve as a dosing pump, and it’s conceivable all of these could be done within a single application. Being able to drive the motor forward and backward could be helpful in clearing jams, or to reverse the flow of a gear pump for example. So we can say this motor can be driven synchronously, or at variable speed from extremely slow to high speed all with high torque, or even as a stepper motor. If we wanted to extend bragging rights we could include a wiring harness that allowed for all three and call it universal or maybe omniversal to distinguish it from the universal stepper style.

One style of synchronous motor becomes four styles.

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5 Becomes 25

Before moving on from synchronous styles I want to touch on two pole synchronous styles. As we know, changing the number of poles changes the speed of synchronous motors given the same frequency. Thus, four pole motors of this style will run at a higher speed than 6 pole motors. This will benefit some applications all by itself.

We can make a case for changing the geometry of the magnets and stators to increase the number of variants, say to include 2 poles but we can also limit ourselves to using the set of core components already established. So if we used our four pole stator to create a synchronous motor we’d use four of our magnets in the rotor. The rotor will only hold four magnets located at cardinal points, and with alternating poles; N-S-N-S.

This becomes our fifth style of synchronous motor. However, on closer examination we find we can drive this four pole synchronous style of motor similarly to the six-pole version to give us synchronous, variable speed, and stepper styles, or with suitable wiring it too can be omniversal and thus claim four styles of motor in one.

We now have another four styles of motor derived from one.

Let’s look at a three phase variant: The permanent magnets in the three phase drive motor are oriented in the rotor in a N-N-N-S-S-S fashion and the corresponding coils are energized with three phases of AC current 120º apart. If effect the rotor, on each side, magnetically speaking only has two poles. That is, the combined north poles and the combined south poles appear to the alternating electromagnetic fields as a single pole each, one N and one S.

A variant on the three phase rotor would be to use two magnets instead of six. This introduces a new part in our overall scheme, which while breaking the pattern of using only 5 core components, opens the door to thinking incrementally differently about what could be done. I won’t add to the total number with this variant, but you can see where this leads.

When we invert DC current to create our three phase AC we introduce some interesting control possibilities. We can mimic three phase line current as generated by some distant power-plant, and allow our rotors to follow the waveforms at the frequency given. Or we can change the frequency, again creating a variable speed 3 phase motor. Again with high torque characteristics inherent in permanent magnet and axial flux motors.

Simply by bringing the leads of each coil or pair of coils out of the motor and taking control of how they are energized, we break away from the limitations we might normally accept from a three phase motor. We could drive these three phase motors in some very interesting ways.

We can run them in either direction, stop them and reverse the direction.

We could drive them like stepper motors, forward, backward, slow, fast, stopping and holding.

We could vary the drive scheme, starting slowly with incremental rotations for example using a stepper scheme, speeding up and switching to a three phase drive scheme or even a two pole synchronous drive scheme.

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5 Becomes 25

So, a simple three phase motor of this design could be driven as a variable speed three phase motor, a stepper motor (bipolar or unipolar and universal are possible), synchronous (two pole) and combinations thereof.

One style of motor (three phase) becomes six styles, not counting the possibility of combining drive schemes in a single motor.

Thus far we’ve broadened the focus of the disclosed work by describing 17 different motor styles that can be made using the same core components. I wouldn’t ordinarily refer to universal stepper as an additional style of motor, but to some degree this discussion is about marketing and being all inclusive and claiming bragging rights so I throw them in the mix.

I still haven’t described two other basic styles of motor that use the same core components. One of them might be a logical variant of what I’ve already shown, but the remaining style I find particularly interesting and quite counterintuitive. It has unique characteristics I’ve not seen in anywhere. It should fit applications that no other motor can. It will remain confidential for now.

If we take the remaining two undisclosed basic motor styles and expand on them by including other possible ways to drive them like we did with the others we would add anther eight (or more) styles of motor plus there’s the possible combinations of ways to drive them.

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5 Becomes 25

To this point I have defined 25 styles of motor that use the same core components. Make changes to the core components and the number rises.

Some of the styles of motor are designed to run on line current and some are designed to run on DC (stepper style) or inverted DC. Something I’d like to mention here: all motors are AC in that the direction of the current inside every motor changes direction. The current running to a motor may be DC and switch inside the motor as with motors having commutators, or the current running to the motor may be AC.

Brushless motors use electronics to switch DC to AC without mechanical brushes used in commutators. There are various ways to perform brushless switching of DC to AC. Some, but not all of them require sensors to detect rotor position. This bears repeating; not all brushless motors require rotor position sensors.

With the advent of super-low-cost cell phone computers (one system on a chip with CPU, RAM, WiFi, Bluetooth, etc. costing $9 US) we can create low cost driver hardware that can be used to drive all of the above 25 styles of motor and it can do much more. Software can be specific to particular styles or applications, or generic, or both. Dumbing down when sophisticated control isn’t needed.

A low cost control board having WiFi and Bluetooth built in means all of these different styles of motors can readily jump on the internet of things. Performance and fault conditions can be monitored and addressed from a distance. An unresponsive pump motor could be ‘jiggled’ back and forth to possibly clear a jam. Speed and thus flow rate of a pump can be changed to suit changing conditions such as temperature, pressure, and so on. Of course other functions can be included to address application specific needs, but the main point here is to show how these motors are highly suited to being used in these and uncounted other ways.

The ecosystem of controllers, drivers, software and hardware that grows up around this platform technology will contribute to it’s growth and stability.

The modularity and adaptability of the core components to be used in 25 plus motor styles and the fact they are one half of an even wider range of hybrid machines makes adding up the potential uses an exercise in speculation at best. The implications are extraordinary.

I am currently considering positions and other offers with R&D in industry or Academia. If you would like to discuss these hybrid machines with me, please don’t hesitate to reach out.

Steve Kubestevekube@gmail.com

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