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The Gaffer's Philosophy:
Part 163: Loose End Five:
July 18, 2005:
In my previous essay, I began a discussion of the design of a true hybrid car. It begins with finding a real team leader. A major task of the team leader is to then create an overview along with a skeletal or strawman design of the product. He must do this to the extend that he will know in reasonable detail the talent needed to bring off the assignment. The major components of the product must be known. This is not a simple task and may require the team leader to be knowledgeable in the product area. Barring that he must work with a very knowledgeable experienced person to create this overview design.
This hybrid automobile is my selected example. I really intend to form a company and create this product if I am still alive when I finish my five philosophy books. I fully believe a true hybrid car is possible. As a consequence, I have thought a great deal about the problem. My requirements for ths marvelous machine are pretty demanding. It must have better performance that the Corvette. It must give between 80 and 100 MPG with emissions less that 10 percent of a standard 2004 entry level automobile. Tough, I think, but doable.
So what does this machine consist of in an overview design. I am talking about a hybrid passenger automobile. For that, I believe there are six major components to be designed and integrated. These six are the components container, the passenger container, the drive units, the power converter, the storage unit, and the control system. None of these is trivial. Once these are defined by the team leader, they will become the beginning specification for the actual component designs. We can take them in any order, but we must know that the design of the components container can only be completed when we know the shape and size of the other major parts.
I will begin with the conversion unit. We usually do not call
the engine in an automobile a conversion unit, but that is indeed
what it is. It takes fuel, which is a form of energy, and converts
it into motion, which is a different form of energy.
The biggest difference in our hybrid version is, we will take
fuel of some kind and convert it into electrical energy rather
than motion. Motion may or may not be involved as a step in this
conversion.
A major problem with the gasoline engine is inherent in its very nature. Many people may not realize that a gasoline engine is, by its very nature, a constant speed device. However, for our automobile to be practical it must run at a range of speeds, from 0 miles per hour (MPH) to perhaps 150 MPH. Our gasoline engine does not like to run as a variable speed device at all. It will resist that and punish us with huge fuel demands when we force it to work that way. Here is another little know fact. An automobile uses very little fuel when it is running at cruise speed. Most of the fuel we use is expended in acceleration and deceleration. Drag racing is very expensive in terms of fuel.
The fact is, most of what is called engine design is just the solution of the difficulties caused by trying to use a constant speed device in a variable speed situation. This has to do with carburetors, fuel injection, spark control, valve timing, and many things that would simply fall out if the engine were used as a constant speed device. The hybrid car, if properly designed, will avoid many of those problems and their associated fuel loses.
What the hybrid must do, if it uses a gasoline engine at all, is to use it in its most efficient native mode as a constant speed device. Perhaps the best way to do that is to run the engine at constant speed to generate electricity which can be stored and used as needed. Then the stored electrical energy can be used to run a naturally variable speed device, the DC electric motor. The DC electric motor is a variable speed device whose output torque will vary with the electromotive force (EMF) applied. The more power we apply, the faster the motor turns. Within the rated range of the motor, there is no inherent loss of efficiency in this conversion.
In this system, energy storage is the big stumbling block. The industry is struggling to find realistic energy storage solutions. We need to store enough electrical energy while cruising or at rest to supply the huge demands of acceleration with a nice reserve cushion. Clearly, Ford has not solved this problem. The performance of the Escape bears that out. The 300 volt battery is not a good solution, it is not a solution at all. It is a man killer, nothing less. When some backyard mechanic gets himself killed with this portable electric chair Ford will think the crash-and-burn Pinto was a trivial problem.
A good solution must come from outside the automotive engineering box. Inside the box, the engineers think batteries. In fact, most of them think lead acid batteries. That is why they are so delirious about this nickel battery. They think of it as a huge breakthrough. Never mind that nickel batteries have been used in electronics for decades. We do not know what a good solution to the energy storage problem is and we will not know until someone gets outside the automotive engineering box.
I have some ideas of my own on the storage problem, but they are not ideas I will share with the people who got sued for stealing by the real inventor of the variable speed windshield wiper. Bob Kerns won his lawsuit against Ford after he died. That may have been a vindication, but it was hardly a victory for him. What I learn from that is do not trust William Clay Ford or any other Ford, or any corporate manager under any circumstances. They usually have no ideas of their own, but they do have highly paid lawyers who know how to use the system.
Okay, assuming I can solve the storage problem, how can I drive this vehicle? That is, what will the drive motors look like? I will take this opportunity to point out a stupidity in current design. That is to have the drive unit as an integral part of the engine transmission drive train. That is just another example of the inside the box thinking. A drive train is a drive train is a single integral unit. Well I am here to say, nonsense. We lose some of the most useful concepts of the drive system by insisting on having a drive system integral with the conversion unit. There should be no mechanical connection at all between the conversion unit and the drive units. The only connection should be electrical through the storage device.
The drive motors must be an integral part of the wheel assembly. With the drive motors as part of the wheel assembly, we gain a number of advantages. First is the final solution to the all wheel drive problem. Four motors in the four wheel housings have this feature inherent in their design. In addition, all wheel steering is a no-brainer with four drive motors instead of one. The units are naturally separate and more easily controlled. Then we have the matter of braking being a mere reversal of the power applied to the motor. Finally, the wheel housings become interchangeable. We need only design one. The other three are identical.
Control of this vehicle becomes a matter of centralizing the drive control into an operator consol. Clearly this consol must become a component inside the passenger container. As to the conversion unit, it becomes an automatic function. When the vehicle is energized the converter starts and runs at constant speed if it is a gasoline engine. It continues to run until the vehicle is de-energized. The energy is transferred to the storage unit as needed. The biggest idea of the control unit is to keep open the option of a future driverless car and to build in that functionality or at least put nothing in its way.
For vehicle safety, the components container must be a separate unit from the passenger container. It must accommodate all of the other components and the passenger container into a slick attractive package. This kind of styling was evolving just before WWII and it got lost in the shuffle. After the war we saw the matchbox on top of a bigger matchbox styling (Styling?) and we never got back to the trend that had begun so promisingly. Sad, but true.
The passenger container must be designed with safety and comfort in mind. It is a separate unit and it must never be an integral part of the components container. It must be designed such that, in the event of a crash, it would float and ride up over the converter and all other components while maintaining its structural integrity. In most case this would save lives. There is a tradeoff. I'm sure we could picture the rare situation where it could lead to further tragedy. There will never be a sure fire method of passenger safety until we have a true driverless car or some other way of moving people and cargo.
There is a lot more to this hybrid automobile and I have a
number of ideas to be tested. There is no way I will spell these
ideas out here to the extent that they can be hijacked by the
brain dead auto industry. I will save them for myself or my offsprings.
In my next essay, I'll get into some of the other problems of
corporate America and of government collusion.
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