Message from our CEO

The Linear Labs HET motor is not a traditional motor.

The best method today to achieve high torque output is a high speed motor with gear reduction or a large diameter motor. Therefore the industry goals have been to develop solutions to achieve ever higher and higher RPMs by various methods.

Hub motors are a brilliant idea. Unfortunately the current motors on the market have not proven to be the ultimate solution for the industry, neither the radial or axial flux hub machines have delivered on their promises.

The HET motor is the new paradigm in volumetric torque direct drive motors.

Our motor is a 3 dimensional circumferential flux 4 rotor machine. The HET motor is a new class of motor and these new motors currently produce torque up to an 8:1 gear ratio for the same size permanent magnet machine used today. This produces unprecedented high torque and very high efficiencies at low RPMs.

All the new R&D innovations today in power electronics, cooling, materials, mechanical designs etc. applied to the HET motor produce even more benefits.

We believe the drive system of the future is a direct drive system, no gearbox, no expensive high RPM mechanical designs with simple, less expensive power electronics.

This is the Motor of the World

Brad Hunstable

Why Linear Labs HET Motor?

Let’s start by calling your attention to this graphic. Notice both motors have the same horsepower but very different sizes and geometries. Both have been designed to service very different applications. It simply is not possible to get high torque and high speed in the same package. Until now..

Linear Labs’ new motor technology allows high torque and low speed operation as well as high torque at high speed in the same package, while maintaining extremely high efficiencies.

This useful capability means it is possible to eliminate geared reduction such as gearboxes and is especially useful for direct drive applications yet it retains the capability to perform at extremely high speeds when desired, while maintaining maximum efficiency throughout loading curve. Numerous novel features have been introduced for the first time in the Linear Labs technology that allow this.

The Technical Chops

The Hunstable Electric Turbine (HET) is an exterior permanent magnet circumferential flux 4 rotor machine.

Innovative concepts are introduced in the magnetic structure and operation at the core of the HET, resulting in large amount of torque generation.

3D Magnetic Structure

The HET’s circumferential 3D magnetic structure produces four active torque producing areas with all sides having the same polarity.

Copper Savings

As much as 30% of the typical copper needed is reduced by having all the copper in the coil involved in energy conversion.

Max Torque

The structure of the HET ensures that all of the magnetic field interactions are fully involved in the production of torque.

Reduced Volume

The unique design requires no unproductive open spaces. Only the air gap surrounding the coil is left open. Think of the possibilities for new technologies that can be created now that you have access to a smaller sized machine that generates the same amount of torque as current industry bulky counterparts.

Large Lorentz Force

The HET produces a large Lorentz force component and a large reluctance force that peak simultaneously.

An important thing to note is that by extending the length of the magnetic tunnel region, the torque that is present throughout the coils travels without regard to the coils at pole face length. Unlike existing conventional machines where torque is only present at an optimum point as it approaches a magnetic pole, the HET has no single optimum point but rather all positions exhibit maximum torque.

The torque and force will exist while the coil is in the tunnel, regardless of tunnel length.

Electronic transmission

In mainstream motor technology, a noticeable amount of torque pulsation is present when large forces are placed on the motor shaft at low speeds. In a typical three phase supply, current pulses are injected sequentially to create a rotating magnetic field. These pulses must be timed for optimum torque production resulting in a single instant in time where only a single phase is essentially active. Electronics can be manipulated to some degree to soften the pulsations.

Due to the larger forces present in the HET Motor, a different approach can be utilized. For example, in a 48 coil, 8 pole example, 6 phases are used to create a smoother acceleration. However, our technology allows for all phases to produce a continuous pulse of power. With the power pulses overlapping rather than being sequential, torque pulsations are noticeably absent and for a given current level, torque is also much greater than conventional machines. This allows maximum torque production in addition to the greater torque integral of our design.

Another advantage is that phases can be software controlled to be grouped into particular patterns. For example, phases A and B can be controlled to act as a single larger pole. Likewise, C, D, E and F. Conversely other groupings are possible with A, B, and C or D, E and F acting as single poles.

This process allows for a true variable pole count, allowing a software-controlled speed/torque relationship to be developed. This allows a speed change increase with no changes in frequency, current or voltage level, which makes an electronic transmission possible.

Field weakening

Permanent magnet electric motors will produce a peak torque at 0 RPM, which continues up to its max rated RPM. This is known as the Constant Torque Region. Techniques have been developed over the years to increase speed beyond this region by trading torque for speed. This technique is called Field Weakening. By weakening the magnetic fields, excitation speed will increase as torque drops.

In induction motors, reducing the excitation current will result in a speed increase. In permanent magnet motors, an opposing current must be injected. This is known as D axis current injection. This area of speed increase is known as the Constant Horsepower Region. Here, torque is traded for speed but the total horsepower does not change.

In both of the above cases there is a radical drop in efficiency. The HET Motor addresses this need in a completely different manner. By slightly rotating a single side rotor, an axial magnetic component is introduced. This weakens, as far as the coils are concerned, the total magnetic field experienced by the coils. The degree of field weakening controls the tradeoff between torque and speed.

For the first time in electric machine history, as the HET Motor enters the Constant Horsepower Region, core losses drop and overall efficiencies actually climb!