Hunstable Electric Turbine (HET Motor)

Hunstable Electric Turbine (HET Motor)

This “HET Motor” design looks promising (if they can bring it to market, obviously.) There appear to be many advantages to the Hunstable Electric Turbine, all of which are relevant to electric cars—for example—and perhaps most significant—it would eliminate the need for a reduction gear-set, with its associated weight, cost, space, energy losses, and potential to break. (When a stand mixer fails, it’s nearly always a stripped gear or broken shaft; on the rare occasion a Tesla Drive Unit fails, it’s most often something in the reduction gear-set, not the motor itself.)

The HET motor’s most important application could be in cars (and trucks, trains, ships, and planes), but myriad products would benefit from motors that run slower and produce enough torque to obviate reduction gear-sets or belts & pulleys. A cursory look around my home reveled a number of machines that would be smaller, lighter, cheaper, more efficient, and more robust without that current necessity: blender, stand mixer, drill, washer, dryer, air-conditioner.

Linear Labs seems closer, and more likely to impact range, reliability, weight etc. than anyone claiming the next breakthrough in battery chemistry. I’ll bet Tesla is watching this:

reed_lewis | August 20, 2019

As TeslaTap always has said, until I can buy it, it is just an engineering prototype.

jimglas | August 20, 2019

it would be hard to improve upon Tesla performance and reliability | August 20, 2019

There isn't much said about this motor, but from what the description implies, it may have limited torque at higher RPMs. This may be inadequate for automotive use unless you use a transmission for higher speeds. Still, it shows promise. Who knows, maybe in 10 years all EVs will be using it. There are so many demands on EV motors - weight, size, efficiency, wide temp range, shock, torque, RPMs, longevity and more. Improving one area may reduce other critical constraints. It's easy to get one or two of these constraints right, but very difficult to get the right mix for EV use. So far Tesla appears to be 3-5 years ahead of everyone else in motor design.

DanFoster1 | August 20, 2019

@reed_lewis: Yes, which is why I wrote: «…if they can bring it to market, obviously,» in the very first sentence.

@jimglas: I agree 100%, but improvements in motor design, specifically: running in a RPM range which would eliminate the need for a reduction gear-set would indeed performance and reliability, *if* it becomes a mature product (as I wrote.) Just recently, Tesla improved the range and performance of the S and X by “Raven” by changing the front motor. Don’t discount the effect of wasted energy, weight, size, parts etc. of a reduction gear-box. Tesla engineers are tasked to find efficiency gains wherever they can—that’s how Tesla has stayed far ahead of all other makers in range, performance, efficiency, and reliability—so you can bet they’ll eliminate the reduction gear-set if that becomes feasible (or another maker will first.) And we’re just talking about cars (as I wrote.)

Does anyone read anymore? Or just skim headlines and dismiss?

jimglas | August 20, 2019

New motor and battery warrantee is 8 yrs, unlimited mileage.
Its going to be hard to improve on that | August 20, 2019

I'm curious - does anyone know what the efficiency loss of the gear set is? I've always assumed it is in the 1% range, but possibly more. Not as concerned about longevity, but that could be a factor out at 300+K miles.

DanFoster1 | August 20, 2019

As I wrote, there are countless products which would benefit greatly from motors that run slower, produce more torque, and don’t require reduction gearing. For example, I could really use a cordless drill that’s thinner, lighter, more robust, and which produces more torque. An electric auxiliary drive for sailboats would benefit massively by ditching the reduction gear. There are now all-electric fast power boats—again, the reduction gear-set in these boats is a major source of energy loss and weight, but there is not yet a motor which obviates the gear-set.

Yes, I’m excited by the possibilities for cars, but there are many other products. I would continue, but it’s clear you’re just skimming and dismissing.

Magic 8 Ball | August 20, 2019

What is "turbine" about this motor?

What is the "jerk" factor (how fast can it accelerate)?

DanFoster1 | August 20, 2019 Indeed it’s a complex issue, and difficult to calculate. But be assured energy losses through gears are exponentially more than 1%, even though Tesla’s gear-set is much more efficient than the gear-set in my Kitchen-Aid stand mixer.

The point at which a gear wheel contacts another gear is called a point of ‘engagement.’ Mechanical engineers assume a 10% loss *per point of engagement*!!! Yes, the Tesla gear-set is a superb piece of engineering, but there are at least several points of engagement. So this is enormously significant. As I’ve said: if there’s a feasible way to eliminate the gear-set, they will ASAP—and they will enjoy massive effect gains. Not just cars. Everything currently powered by motors wastes significant energy through gears (or belts & pulley, which are more efficient, but too fragile for many applications.)

Linked below is an introduction from an expert; as you will read, this is huge:

Neomaxizoomdweebie | August 20, 2019

Another awesome example of how brilliant entrepreneurs will lead us to a cleaner, cooler planet.

andy.connor.e | August 20, 2019

We will be hit by an asteroid before global warming kills us.

Neomaxizoomdweebie | August 20, 2019

That may be true. I’ll continue to support innovators who build things that stink less than diesel. Go Capitalism!!

andy.connor.e | August 20, 2019

same! Im looking into getting the solar roof next year.

johncrab | August 20, 2019

I'm only seeing a longer rotor/stator section and what amounts to timing shift, the latter of which being the most significant. The former, is an application of Pascal's Theorem of force over area. The latter is not spoken of in detail but I am curious because it is akin to varying the ignition timing in an ICE engine. I learned long ago not to dismiss new ideas or in this case, new spins on old ideas. After all, that's what gave us the remarkable Tesla drivetrain. I think there will be many ideas like this in the coming years and some will work and some will not but getting them out of theory and into practical use is the only real way to judge them.

blue adept | August 21, 2019

Great, yet another hub-style motor concept.

sorianocary | March 9, 2020

Until they can demonstrate all the claims in an actual EV prototype (not a scooter) I don't think Tesla should feel threatened by this at all. Will have to wait and see how it does in real-world tests (ie how it impacts performance, range, and battery life)

blue adept | March 10, 2020

If it's only about an increase in efficiency due to the elimination of a gearbox why not simply mate the motor directly to the axles viia an LSD (it's how I do my ICE-to-EV conversions)?


No transmission and a resultant exponential increase in efficiency. | March 10, 2020

@blue - That would reduce the torque by a factor of about 9. It may work, but the 0-60 time would be much slower. Of course, the software would need to be modified to reduce the motor speed by the same 9:1 ratio. On the plus side, the top speed (ignoring air resistance) could be 9 times higher - 1450 mph!

blue adept | March 10, 2020

There's the potential that there will always be some sort of trade off, though it's arguable that the 0-60 time depends on just how quickly the motor is able to spool itself up and, in particular, the sizing of the pinion and ring gear.

Much the same would apply to the top speed.

Oh, and I've firsthand experience that it does work.

blue adept | March 10, 2020

I will not comment on any numbers related to the consequent "top speed".

blue adept | March 10, 2020


The more complexity you introduce into a system the more you lessen its efficiency.

jimglas | March 10, 2020

and more things to break

andy.connor.e | March 10, 2020

and higher cost | March 10, 2020

and more complex to service

jimglas | March 10, 2020

The beauty of the tesla drivetrain is its simplicity and reliability

blue adept | March 10, 2020

@jimglas, @andy.connor.e, & @jimglas


blkice | March 11, 2020

And harder fix or diagnose problems