In-Wheel EV Motor From Evans Electric Unveiled In Australia
The Australian company Evans Electric has developed an electric car that is literally direct drive. It is a 4-door sedan, a Mitsubishi Lancer Evolution, that produces 800 HP/600 kW (peak) and 5,000 Newton-metres (3,688 foot-pounds) of torque.
“While the torque figure could at first glance appear fantastic, standard automotive industry practice only quotes torque at the flywheel not at the wheels,” Evans Electric notes. “As an example the Tesla Model S Performance has a quoted peak motor torque of 600 Nm. With a single speed reduction gear ratio of 9.73:1 that equates to a total of 5,838 Nm (minus gearing losses) at the wheels. The Evans Electric motors are direct drive, so the rotor turns at the same speed as the wheel. Instead of mechanical reduction gearing, they are electrically geared using an 8 pole stator winding configuration.”
To help you understand the significance of that: direct drive equipment has the benefit of mechanical simplicity, and sometimes efficiency, as the alternatives, which are gear-driven systems, waste energy.
Mechanical equipment cannot get any simpler than direct drive. This is because the motor directly turns the wheels itself. In the case of this Lancer Evo 3 vehicle, it has an electric motor integrated into each of the four 19″ (48 cm) wheels. No gears, no transmission, nothing at all.
The most reliable equipment I have ever used is direct drive.
Image Credit: Evans Electric.
This vehicle can achieve electromagnetic braking. No friction. Friction brakes are inherently inefficient because they dissipate the kinetic energy that moves the vehicle as heat and wastes it until the vehicle slows to a stop.
“The Evans Electric in-wheel motors enable non-contact electromagnetic braking, replacing hydraulic friction brake systems which are 99% redundant in current generation electric/hybrid vehicles. Using only the wheel motors, the car can brake at greater than 1G.”
The Evans Electric in-wheel EV motor, powering a Lancer Evo 3, was just unveiled at Meguiar’s MotorEx at Sydney Olympic Park. Here are some more notes from Evans Electric about its technology:
Evans Electric hold a patent for a vehicle drive system using wheel motors for propulsion and braking, the most impressive feature of which is that safety and vehicle dynamics features such as ABS, stability control, traction control, brake steer, active brake bias, torque vectoring, intelligent cruise control, emergency brake assist and collision avoidance all become customisable and upgradable software functions.
When these systems are combined with wheel motors they allow a new level of performance based active yaw control that unlike most current stability control systems (which only activate in an emergency situation) are active at all times, dynamically fine tuning understeer and oversteer to enhance cornering speed and safety.
After an extensive period of wheel motor validation testing and power electronics development the company has met with several automotive Tier 1 suppliers to discuss collaboration &/or licensing to move the project from proof of concept to commercial product development. Final preparations are under way with track testing expected to commence by the time the Bathurst 1000 rolls around in October.
Notably, this isn’t the first in-wheel electric motor we’ve featured on CleanTechnica. Protean is supposed to be bringing an in-wheel electric motor of its own to market in 2014.
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“that produces 800 HP/600 kW (peak) and 1,250 Newton-metres (925 foot-pounds) of torque.”
This need correction, it’s mixed up. It’s 1,250 Newton-metres (and 150 kw-s) per motor. So it’s four times that for the whole car. 600 kW for power and 5000 Nm for torque. With no gearing loss, so in all likeliness it’s significantly more than Tesla’s.
The guy at the “Electric Vehicle News” blog wrote about it previously.
http://www.electric-vehiclenews.com/2013/03/wheel-motor-validation-testing-confirms.html
He probably has ties to Evans electric. Because there are hardly an news about it elsewhere and he disabled comments when I asked about it. (And revoked my commenting permissions like a real jerk…)
revoked ? you are still on here commenting though hmm……?
?
I can’t comment on that blog. That’s what I said.
ok, ok,
Corrected. Thanks.
Cool.
I followed the reference chain. Here: http://green.autoblog.com/2013/07/29/evans-electric-unveils-monster-in-wheel-motor-down-under/
In the copied press release (I don’t know where they got it from because there’s nothing on the Evans Electric website) it says:
“Each Axial Flux 3 phase AC Induction wheel motor has a nominal output of
75 kw and 625 Nm of torque with a peak output of 150 kw and 1,250 Nm
giving the vehicle a total peak output of 600 kw (800 hp) and 5,000 Nm.*”
Of course, having the motor drive at each of the wheel have some problems that should be addressed. I wondered if they have covered this. First and foremost the wheels would be very expensive to repair when it hits potholes, curbs and other hard objects on the road. The roads in the US are not as well maintained as they used to be. Second, the wheels would be heavier from the added weight of motors, so it could affect the feel of the ride, especially that we will have more unsprung weight that can transmit to the chassis instead of being absorbed. And the third important one is that the direct drive motors should be truly robust and heavy duty because it will suffer much more abuse as it will have direct impacts when the wheels hit uneven objects such as pot holes, hard objects, curbs, and also more exposed to the elements such as direct contact with water or erosive salts, compared to motors that are snugly kept under the hood, well protected. It is a real world out there, not in neat racetracks or laboratories.
I’ve never heard of pothole related damage outside of ruined tires and bent rims.
As for unsprung weight…
“A stock 2007 Ford Focus was compared with an identical vehicle modified with 66 lb (30 kg) of ballast fitted to each wheel. The weight was distributed between rotating and nonrotating unsprung masses as to broadly replicate Protean Electric’s PD18 (18-in diameter) wheel-hub-motor unit. The project plan included three phases of analysis and testing.
Phase 1 focused on modeling of different modifications, including suspension spring, bushing, and damper rates, and different tires and pressures, and their effects on the IWM-equipped vehicle. It was determined that simply fitting a standard Focus ST suspension (an upgrade on the stock base car) would be a good practical solution.
In phase 2, the stock vehicle was modified with the Focus ST suspension. This setup included revisions to the front and rear spring rates, dampers, and the rear antiroll bar. In phase 3, the Focus with the modified ST suspension was retested. The process included a subjective vehicle assessment, objective ride and handling tests, on-road shake measurements, and two-post shaker rig measurements.
The studies concluded, and the presenters argue, that while the vehicle carrying the greater unsprung mass at each wheel did display perceptible differences compared with the stock vehicle, those differences were minor and can be mitigated using “normal engineering processes within a product development cycle.”
By fitting the upgraded ST-level suspension to the car replicating one equipped with Protean PD18 in-wheel motors, the vehicle’s handling and on-center tracking were improved back to reference. Overall, the effort conducted by Protean Electric, Lotus Engineering, and Dunamos may help convince skeptics that the addition of 30 kg of unsprung mass per corner will not adversely impact overall vehicle dynamics and can be addressed fairly easily with cost-effective countermeasures.”
http://ev.sae.org/article/9493/
Yes, the motors will be subjected to more water, etc. We build electric trolling motors that spend their working hours under water. And bow thrusters for large ships that spend their lifetime under saltwater.
Proper steel rims are not easy to break. I don’t remember hearing of one broken. Roads suck here and people drive fast.
Aluminium rims and such are a fad.
Very cool, wondered when they would finally do this.
Just wondering about the max braking and power loss…if the systems are redundant, then a component failure should not be an issue…welcome to flyby wire in a car….
Remember when you made a huge tantrum about these things and got fired. Lolz.
What do you mean fly-by-wire? You need steering.
Also 1G isn’t enough for breaking. Every stronger braking is more than that.
Mitsubishi were testing this technology many years ago – http://www.mitsubishi-lancer.info/news/Mitsubishi_Lancer_EVO_with_in_wheel_electric_motors.html
Nope. Although the in-wheel motor concept is not new, the axial flux design’s are. And they have better power density and they’re slim which is good for something that’s in the wheel.