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Inventor Demonstrates Infinitely Variable Transmission
ElectricSteve writes with this excerpt from Gizmag:
"Ready for a bit of a mental mechanical challenge? Try your hand at understanding how the D-Drive works. Steve Durnin's ingenious new gearbox design is infinitely variable — that is, with your motor running at a constant speed, the D-Drive transmission can smoothly transition from top gear all the way through neutral and into reverse. It doesn't need a clutch, it doesn't use any friction drive components, and the power is always transmitted through strong, reliable gear teeth. In fact, it's a potential revolution in transmission technology."
Well, one potential flaw is the eccentrically mounted components. Unless properly counterweighted, at high speed this will cause a lot of vibration.
BTW, couldn't you do this sort of thing with a differential?
When our name is on the back of your car, we're behind you all the way!
It works as a demo very well I , as an ME agree.
The big issue in science and engineering is ALWAYS reduction to practice. The inventor acknowledges this and is working with an engineering firm to make a practical pseudo-production testing model. When you have no clutches, the lack of shock loading means the size of gears and the housing can be substantially reduced, since there won't be an engine load shock issue. There can be issues of loads when parked, though, when another car bumps yours. The other issue is how do you tow such a car when the engine fails or you want to tow it behind a motor home? There may still need to be a "cog" connection for towing.
Issues involved in getting it into a small, produceable and cost effective prototype will tax the engineers. If they can do it, there will be applications in many different fields.
Given that the gear ration can be set by controlling the small electric motor speed, it can be integrated with other electronic control systems easily.
I have to hand it to the guy for coming up with a very clever implementation. This is why we need to support the math, science and physics departments everywhere, because in the end, the world is a physical place and the countries who prosper the most will be the ones with the most technologically up-to-date innovators.
Assuming 1000 miles per month (which is what most leased cars are allocated) :
The difference between a 150mpg car and a 250mpg car is 32 gallons of gas per year per car.
The difference between a 30mpg car and a 40mpg car is 100 gallons of gas per year per car.
The difference between a 20mpg car and a 30mpg car is 200 gallons of gas per year per car.
The difference between a 15mpg car and a 25mpg car is 320 gallons of gas per year per car.
The difference between a 12mpg car and a 22mpg car is 450 gallons of gas per year per car.
The difference between a 10mpg car and a 20mpg car is 600 gallons of gas per year per car.
Read from bottom up, you see the point of diminishing returns.
If car companies would focus on the right range (forget about exotic expensive 150+ mpg carbon fiber hybrids that hold two people, focus on 30+mpg vehicles that hold a family and gear) they would have a LOT more impact. I don't necessarily agree with the way cash for clunkers was handled, but in the cases where people traded in a 12 mpg car and drove off in a 22mpg car - it makes a BIG difference.
Glonoinha the MebiByte Slayer