EBTX Engine & Tranny


(^These gears are just for fun^)

T   
his is an original design for a gasoline engine [positive displacement]. Though I haven't seen it elsewhere in books, I suspect that a similar design has already been experimented with and rejected for whatever reason (which I would be very interested to know - if anyone reading this has info please email).

I don't research my designs/inventions much beforehand because I don't wish to prejudice my judgement and/or lose the fun of inventing the thing all over. Finding my finished design in a book by someone else is actually quite enjoyable. It shows that my judgement is not unique ... only isolated.

Here's one of my designs by way of example.

I discovered that this "dingus" was first employed in the middle ages (or was it dark ages?). Anyway, it's quite old and I had the privilege of 'reinventing' it. It's called a "half gear" and turns rotary into reciprocal motion. (And, yes, it's not drawn too well ... )

Here's the core idea :

Get rid of the crankshaft and replace with rotating drum
with "sine wave channel" to run standard pistons in.

Note : This animation may be too slow in Netscape 3.0.
It runs fine in I.E.3 & 4.
As you can see, this "crankshaft" is much more easily machined than a standard one and if an even number of waves are present in the 'track', it is necessarily always in balance.
Since, two diagonal pistons are synchronized with the other two (two up two down), the center of mass of the engine is stable.
Therefore, the engine is vibration free in principle except for torque applied to the transmission on each power stroke.

Advantage of this engine type

There are other advantages to this scheme besides "no vibration".

One is the option to 'cut' the channel in a manner other than a sine wave. For instance, one might want the piston to linger at the top of the compression stroke in order to allow for more complete burning of the fuel before using the energy on the downstroke. It might be possible to tweak some more efficiency out of internal combustion.

The piston and piston rod are one solid unit eliminating "sideslap". It might also be possible to lay the engine sideways and mount two pistons on the same rod thereby creating a size minimized eight cylinder engine (all pistons running on the same sine track).

The camshaft is easier to machine being now a plate mounted on top to the engine connected directly to the main shaft. (It can also double as the flywheel.) As the drum turns, raised metal on the plate activates the valves which can be accelerated to open and closed positions at any desired rate.

This can be a very light engine. No counter weigths are required on the crankshaft for example. I estimate the size of a stock four cylinder engine to be about 12" x 12" x 18" which means you could probably pick it up and carry it to the basement for maintenance by yourself (... though I wouldn't personally advise it). An 8 cyl. engine mounted sideways wouldn't be much larger ~ 12" x 12" x 24" .


Problems inherent with this engine type

There is a torque put on the piston rod particularly on the power stroke which must be handled by having the rod run up and down in a sleeve.

Because of the simplicity of machining and the quality of modern oil lubrication, I would attempt to build this engine without bearings in either the rod sleeves or sine channel connection, that is, I would like to see how long such a setup could be made to last and whether it would be cost effective to just let the engine wear out and replace it every ~50,000 miles.

On the intake stroke the piston rod connection to the sine channel is pushed to the top side of the channel whereas on all other strokes it is forced to stay on the bottom side. This might cause an audible clicking sound when the connector goes from bottom side to top. One way around this would be to "ram" air into the cylinder rather than using the piston to "suck" it in. In this way the connector would always be in contact with the bottom side of the channel.

Automatic Transmission

The transmission of choice (for me) would be an infinitely variable positive displacement one. And there is only one way (realisticly) of accomplishing that. It is to use a gear pump mechanism.

Here, fluid is pumped by the engine and sent back for repumping while sliding 'vanes' change the gear ratio as the housing is moved relative to the fixed output shaft.

This has been around for many decades (used on Ford tractors as early as the 1920's). This is another gizmo I had the privilege of 'reinventing' (see? ... don't look for the thing first ... you might find it ... then what have you got to do?).

Why this is not used on passenger cars is unknown to me. I don't think heat dissipation or leakage is a problem and the mechanism certainly seems robust enough (after all it was ... maybe still is ... used on TRACTORS!) ... ?

Consider that the Wankel engine made it all the way to production (a very difficult technology). Maybe engineers can't deal with this? No ... can't be that ... whussamatta ??


I also designed this gear pump mechanism which accomplishes a 'near' infinitely variable transmission by running many gear ratios thereby making the transitions between gears less noticeable.

Here we have just three physical gears which when combined in various ways make 7 gear ratios. ( 1 , 2 , 1+2 , 4 , 4+1 , 4+2 , 4+2+1 ) = 7 gear ratios. (Red gears mean "No Through-Flow")

7th Gear (high)

. . . . ENGINE PUMP . . . . TRANS . . . . OUTPUMP

4th Gear (middle)

. . . . ENGINE PUMP . . . . TRANS . . . . OUTPUMP

1st Gear (low)

. . . . ENGINE PUMP . . . . TRANS . . . . OUTPUMP

As fluid from the engine pump is allowed to enter a gear, the "self-return" port is closed and the "from-engine" port is opened. When a gear is closed off from the others, fluid must circulate independently within that gear since all gears are connected to the same shaft and must always pump. "High" gear is #1 and "Low" is #4+2+1 . these gears can be of any size as long as they pump at the desired rate multiple.

Another View of the Same Principle

Here is another simplified schematic version in case you don't understand what I mean.

As trans fluid (blue) is pumped through, the gear ratio changes in increments proportional to the size of each trans gear. As valves close, fluid goes through the gear pump section by means of a "neutral bypass valve" which simultaneously opens. Neutral "gear" would need to simply bypass all gears (neutral bypasses not shown).



This is, to me, the most robust transmission conceivable. It cannot be damaged and requires no clutch because a pressure let-off valve in each gear can be designed to keep the self-return path partially open during transition to engine port path. Such a pressure let-off would be heavily 'sprung' so as to hold shut under normal stress, i.e. the pressure valve is only slightly weaker than the transmission fluid seals at the shaft entrance / exit.

Why this form of transmission is not used is a TOTAL MYSTERY to me.

Addendum ... 3/23/99

No longer mysterious to me.
The purpose of not using such devices is "complexification". By making the engine and transmission more complex, costs are kept up thus ensuring a higher return on each unit sold (since the profit is by percentage).

Imagine what would happen to the auto industry if you could by a cheap dependable car for say $4000 and not have any serious maintenance for ~6 years. And the used car market and maintenance market would be ruined as well.

Here is a good "proof" of the conscious ripoff going on. Your car's computer.

These gizmos cost ~$1500 to install a replacement. Do you really think that it's as complicated as a Dell 400 mghz, 128 mgs sdram and a 13 gig hard drive, 17" monitor - w/ Win98' & all that extra software added to sweeten the deal? Get real ...........

Well, you might argue that it's a specialty item ... but you'd be wrong. They are also "mass produced". And you might argue that they take a lot of research to develop ... but you'd be wrong. They are no more complex than a good pocket calculator. You should be able to buy one at the local Auto Parts Store for $42.95 +tax and slap it into a port like a PCI card.

But that would be too easy ... wouldn't it?

My present view is that this fundamental structure is a viable alternative to the present standard crankshaft model. Why it is not used is unknown to me since it must have been thought of before and actually built. If you have any knowledge in this regard please send info.


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