Hybrid wheel retrofits
A recent tweet by tebbo recommended a short article on a proposed in-wheel electric motor that can be retrofitted to existing petrol vehicles…. “RT @Vibroseis Retrofit hybrid kit for your car using electric wheel motors http://bit.ly/8gLox <<< Nice one Mr ex-IBMer”
Its an interesting idea. The technology proposal is for a set of electric motors to be installed between the wheel and the brake mechanisms, and powered by a battery array in the trunk. The motors will take up some or all of the load with the petrol engine therefore needing to work less, perhaps including down to only an idle speed. The petrol engine wouldn’t be able to be turned off completely when in motion as it will be required to power the vehicles existing essential systems - steering, brakes, aircon, digital-integrated-multi-media-web-browsing-GPS console, and heated 48oz coffee mug holders.
The practical challenges to making such a system work have to be: electric engine power limits; battery technology constraints,; integration with existing controls especially braking (incl. ABS) and acceleration - such systems may be fly by wire or cable/hydraulic; networking of motor units in order to synchronise output across the two/four wheels; the need to support multiple wheel size, stud pattern, rim offset configurations.
Wheel sizes and configurations are standardised more than you might think. A quick check of the webiverse finds that there are probably about 20 combinations of wheel size and stud pattern that are used across a high proportion of vehicle manufacturers and models. The practical consideration of deliverable motive power from the electric motors versus vehicle weight might reduce the range of cars the technology is practical for anyway, so the most common 20 size/stud patterns might well fit 75% of the addressable market. If the electric engine drive assembly is designed to allow for it then additional stud patterns can be bolted on easily. The published design schematic (see figure) seems to indicate that this is catered for.
The other caveat is that of bureaucracy. As the electric motor system is a change to the motive power source of the vehicle, and on paper adds horsepower over and above the existing petrol engine I would imagine that every vehicle in which it is installed will need to pass some sort of re-registration and roadworthiness inspection. There will no doubt be insurance implications as well.
There is another important design consideration - style. There is a trend toward Brake Bling. The designers will do to remember to cater for those who wish to greenvertise their new electric wheels.
Brake bling
Tags: cars, Oil, Random thoughts, Travel