Revolutionary high torque electric motor gets $74M support

High torque electric motor manufacturer Linear Labs has added $6M in new investment to a recent $68.9 million partnership and incentive from the City of Fort Worth, Texas.

The $6M round was closed with participation from new and existing investors including  Lowercarbon Capital, Duke Angel Network and Moving Capital – an Uber-alumni investing syndicate.

The motor generating all this excitement is the HET – Hunstable Electric Turbine – which uses a magnetic tunnel to surround the stator resulting in motors the company says can produce ‘at a minimum, sometimes more, but at a minimum – two to three times the torque output of any electric motor in the world, and it does this at high efficiency throughout the torque and speed range.

The tongue twisting name for the technology is  “circumferential 3D magnetic architecture” which basically means that it combines a radial flux motor with an axial flux motor. Still confused?

Radial flux and axial flux motors

In simple terms, an electric motor has a stator – non moving stationary part – and a rotor – rotating part. Electromagnetic sources are put in each – they can be a material that is already magnetic or metal that is given a magnetic polarity through electricity – and the interaction of the magnetic fields is what makes the motor spin. The density of the magnetic fields as the motor spins is measured as magnetic flux.

In a radial flux motor, the rotor is a cylinder spinning inside a stator tube (or it can be reversed, a stator cylinder inside a rotor tube) and the magnetic interaction takes place along the length of the cylinder/tube. In an axial flux motor, the rotor and stator are discs spinning adjacent to each other and the flux is between the two flat surfaces.

The diagram to the left is BY NO MEANS EXACT but hopefully will give you some idea of the difference between the two. An axial flux motor (on the right) is sometimes called a ‘pancake’ motor, so if you think of the other as a ‘cylinder’ motor (maybe a sausage motor?) you can kind of get the idea. The green shows you where the magnetic flux is, so if you think of a radius and an axle you can figure out why each has its name.

Now if you look at the big image at the top of this article, you’ll see that the Linear Labs circumferential 3D magnetic architecture combines those two – in the middle section it  has cylindrical rotors (driven with radial flux) with pancake rotors (driven with axial flux) on the ends.

High torque electric motor combines both

This is how Linear Labs describes their motor:

“The HET is four rotors surrounding a stator. A central rotor spins inside a stator, creating one source of flux. A second rotor spins outside the stator, creating a second source of flux. Two additional rotors lie at the left and right ends of the stator, essentially forming an AF motor. That’s two more sources of flux, making four in total.”

So while thinking of it as a four rotor motor makes it easy to remember, it is called the Hunstable Electric Turbine because it actually started out as a way to generate electricity, not consume it.

The Hunstable in HET is the last name of a father and son team who are not your usual two-guys-in-a-garage workshop tinkerers. Father Fred spent 18 years working on electrical infrastructure for nuclear power plants, and son Brad started one of the original video streaming services – Ustream- in 2007 and sold it to IBM for $150M in early 2016.

Brad says they were looking for a father-son project, something where they could spend some time together and they started working on the idea of a turbine that would enable a slow moving windmill to generate electricity. If successful it would be hugely beneficial for impoverished communities, especially in Africa.

Electric motor started out as electric generator

An electric motor is literally an electric turbine in reverse, so when Fred ‘cracked the code’ for the windmill, they knew they had something that would have important implications for electric motors. To use the phrase they were ‘on their way’ would put it mildly. The Linear Labs electric motor has been issued 25 patents so far.

The motor was first introduced to the world in late 2018, interest grew throughout 2019, and in 2020 things have taken off.

In April they launched a successful Kickstarter campaign for a small version of their motor, ‘The Honey Badger’. In June the city of Fort Worth, Texas, approved the $69.8M economic incentive package for Linear Labs to develop a 500,000 square foot manufacturing plant in the city.

high torque electric motor inventors Brand and Fred HunstableIn late July they announced they would be starting mass production of their M200 motor with the goal of selling 100,000 by the end of 2021.  In  September they won Frost & Sullivan’s  2020 “New Product Innovation Award”. October 13 they received the new $6M funding and October 22 won the Ernst & Young Entrepreneur of the Year Award (Southwestern United States) and are now up for the national award.

While the company has focused on EV manufacturers so far, a high torque electric motor also holds great promise for marine applications, where weight is a bigger consideration than for land-based transport. A few months ago we wrote how Equipmake, who also make a high power density motor, have started to look at possibilities the boat industry.

We’ve also written a lot about how batteries with higher energy density – packing more energy into lighter modules – are important for boats.

Read all Plugboats articles about advances in solid state batteries

As for Linear Labs, the video below shows off the waterproof aspect of the HET, and they also have a strategic partnering with Swedish electric powertrain designer Abtery who work in all aspects of electric mobility and have Denmark’s Sarvo electric boats as a client.

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