DuPont and BP Partnership Targeting Multiple Butanol Molecules; Testing 16% Blends
Ford Previews Next-Generation Hybrids

BluWāv Exhibits RoadRunner Four Wheel Electric Drive System

The 46 kW hub motor. Click to enlarge.

BluWāv Systems LLC, a provider of hub motors, electric propulsion and energy systems for the military, commercial, automotive and industrial markets, exhibited its Roadrunner four-wheel electric drive system applied in a military vehicle at the 2008 SAE Hybrid Vehicle Technology Symposium in San Diego this week.

BluWāv was formerly WaveCrest Laboratories, the developer of the dynamically reconfigurable Adaptive Motor system, which consists of a multiple-phase, DC brushless motor arranged such that the rotor surrounds and rotates around the center-mounted stator, rather than rotor rotating within the outer stator. (Earlier post.)

The WaveCrest stator consists of a series of independently controlled electromagnets driven by a proprietary power electronics module. The electromagnetic cores are identical and isolated.

The RoadRunner system as shown on a 1,500kg off-road military vehicle uses four 46kW (peak) Adaptive Motor hub motors combined with a 5.1 kWh Li-ion battery pack with A123Systems cells to support an electric range of 15 miles (25 km) with a top speed of 75 mpg (121 kph).

The hub motors provide 20 kW of continuous power, with 620 Nm of continuous torque and 1,100 Nm of pea torque. Speed range is 0-900 rpm reversible.

The motor was designed to package into a 17” rim and integrates the hub (and wheel bearings), a disk brake, and motor into a single unit. Four of these motors are capable of propelling a medium-sized automotive vehicle up to 90 mph and up a 30% grade, according to the company. The motors also provide regenerative braking for increased vehicle range, shorter stopping distances, and reduced brake wear.

The motor is a brushless DC, permanent magnet with an integrated gear set, hub, and brake. The power electronics are IGBT-based with an integrated DSP for motor control. BluWāv develops the motor, vehicle control module and pack and battery management system itself.

In January, BluWāv announced that the recently-passed Fiscal Year 2008 Omnibus Appropriations Bill directs $1.2 million to the company to accelerate its research and develop an energy storage system for hydrogen-based and hybrid vehicles.

The system is to take advantage of the unique attributes of fuel cell start, run, and shut down sequences, provide a vehicle with an electric-only range compatible with a majority of commuter drive cycles, and focus on energy absorption through regenerative braking by incorporating electric drives using the latest BluWāv brushless DC motor technology.


Healthy Breeze

I'm going to go out on a limb and guess the military is interested in silent operation for commando dune buggies. Maybe they are interested in range extension as well. Does anybody think this is a cool implementation?

John Taylor

Si ... silent electric Hummers are coming, and nobody can hear them.

One glitch ... We have two sets of wheel bearings to change, and really short axles, so this can wear out twice as fast. Actually, it is similar to other wheel motors.
Now what was wrong with having the motor frame mounted so it wasn't unsprung weight and not subjected to road shock load? The marginal efficiency improvement from not having drive shaft may cost a lot in repairs.


" speed of 75 mpg" (should be mph)

Since they only have a range of 15 miles, they probably need a range extender.

"...take advantage of the unique attributes of fuel cell start, run, and shut down sequences..."

It sounds like they are thinking of using a fuel cell for a range extender. With water management air blowers, and heat signiture even a fuel cell is not totally stealthy.

WaveCrest, now BluWav needs funding to stay alive and like many struggling small companies they do whatever they can to keep the cash flowing. Government contracts are one way to do that.

Michael McMillan

I believe that the idea is that you just carry a spare wheel assembly or two. If one blows, bolt a new one on.


A lot of it may have to do with eliminating gears and differentials all together. If you are going to have 4 wheel drive, you might as well drive all 4 wheel directly.

This has a sort of "fly by wire" feel to it. You can computer control every aspect of the traction and stability to keep the driver and passengers out of a jam. Computers are much quicker than humans.

This is off topic, but I saw a Japanese luxury car with eight 100 hp hub motors that had a top speed of over 200 mph and a selling price of $260,000. If they had tried to make one large 800 hp electric motor with gears it might have been quite a challenge. Cooling several smaller motors is also a bit easier.

Rafael Seidl

There are certain mechanical and thermal advantages to having a PM rotor that surrounds a central stator.

However, for military applications, switched reluctance drives might be preferable as they require no permanent magnet materials at all. They would eliminates a potential materials supply bottleneck in a war scenario and, could not be rendered inoperable by future weaponry emitting strong magnetic pulses. However, the higher noise levels produced by SR drives - especially if fitted with planetary gear reducers - could be a problem for reconnaissance & special forces stealth assault vehicles.


whats good and whats not.
Good: ground clearance off road application, low centre gravity, would work well with tracked , other oddball configs including thirdwheel or bicycles other industrial applications where a frame is not required.
no jackshaft (CV)
Can be supplied as a four bolt component by manufacturer so as a fitment could have advantages as per previous bolt up comment.

Bad: High unsprung weight. In road transport the weight should be as low as possible and located as close to the polar axis or as inboard as possible.
A central location is more easily protected from snags hence inherently more rugged.
Severe space limitations will lead to heating problems dealing with braking and power. Cooling, controllers, and cable runs are shorter when centrally mounted.
Additional hardware location will require compete redesign of assembly or be omitted.
In development the last imitation is severe.
A central mounted unit should be servicable as L+Right side so serviced more appropriately as a pair.

Both sytems should allow for redundancy in the event that one or two wheels lost power.


Since military vehicles need to drive through deep water I hope this is sealed to prevent water entering the motor.


well.. if some body like to build low noise vehicle, he should look on the ranking cycle engine.
This are moder steam engine with close cycle of expansion. There are extremely quiet in operation, and they power torque characteristic are very similar to electric motors (perfect much for the vehicle). They can use almost any combustion material as a fuel and generate almost no pollution (except for CO2).
The heat signature is definitely lower then any ICE, and it might be comparable or better then hub motors (hub motors are almost totally expose). The whole idea of external combustion engine is to prevent the heat from escaping from the get go. Modern steam engine can deliver 36% to the wheel (the electric motor up to 80-90%...of the maximum efficiency that the ICE have in the best case.

The more I think about the hub motors the less I like them. As somebody point out thy are sitting in the wheel and that create serious issue.
Better idea will be just the more conventional electric motors position on the main car body. The cost will be far smaller and you could have still 4 wheel drive.


I think Michael might have some of the reasoning. Since everything is in one assembly, if it gets damaged it can be replaced like changing a tire.


I can see one weakness for an off-road vehicle. When one wheel loses traction, you lose 25% of your power. In a more conventional setup with one motor and limited slip differentials, all available power is distributed over the remaining wheels.


That is a good point, but you have no differential to wear out and no axles to break either.

fred schumacher

Hubmotors allow automotive design to escape its present morphology which ties up a tremendous amount of oddly shaped internal space for propulsion components.

A series electric hybrid with hubmotor drive could put all its mechanicals below the passenger compartment, lowering the center of gravity, move the much-reduced genset away from the front of the vehicle, where it is a liability for frontal crash absorption, and simplify design of the passenger compartment for maximum internal space with minimum external volume.

Such a vehicle, to replace my present Neon, would need hubmotors with only half the power output of the above design. The lighter vehicle resulting could run on narrower, lighter rims and tires, removing some of the unsprung weight penalty.


Its great to see BluWav continue Wave Crest's inspirations.

Proponents of the continued use of complex & pollution intensive ICE are just looking for bones to pick on EVs. They look to find some arguments to close the gapping technological canyon of superior hub electric motors vs the archaic geared shaft system of ICE.

If ICE adherents can dream up mental scenarios that may have a military advantage, maybe they can transfer those ideas to civilian equipment & slow-down the ideas of efficiency & pollution advantages of EVs.

But there are rebutting arguments to blunt supposed ICE advantages & that EV-ICE canyon of Elegance remains as wide as ever.

electrical fire place

The reunion comes about as result of a fly on the wall documentary being made about Egg. Clare, a young twenty- something, film maker is following Egg's every move and it is she who comes up with the idea to get them all back together. Not surprisingly, Egg has a bit of a thing for Clare. Will it lead to anything...?


Go to the web site of PML Flightlink and see what can be done with hub motors. These are rather low powered compared to PMLs, which are 120 Kw per wheel and lighter.

PMLs hub motors have only electric brakes, and only have a 5lb weight increase over conventional wheel assembles. See there demonstration vehical, a real show stopper.


Military application? They don't care about the unsprung weight; that largely affects the ride, and they just don't care.

Ron Phillips

Could this system be used to modify/repace two-each rear-dual drive-wheels (on a Ford E350 25-seat passenger-bus designed to operate at 20,000lbs? gross vehicle weight, with 159" rear wheel base(factory extended) and both stearing wheels?
Ron, Alaska Bus Guy, 205 Orngeleaf Circle, Anchorage, Alaska 99504-1589

Account Deleted

Caravan Parks
Caravan Wanted TodAy....................
caravan parks

The comments to this entry are closed.