Different crank shaft setup

[allmee]

I have designed a new crank shaft system and was wondering if people would like to see it. sorry about the math post.

[insane_alien]

people have already said yes. why don't you just post it.

[allmee]

[cjohnso0]

I think your sketches need some more detail, for example:

 

Where is the combustion chamber?

Assuming the crank is rotating CCW, what happens to the piston after 'B', it looks like it will fall back onto the springs, then when the crank comes around, it will tear the teeth off on the left side.

 

I'm also not sure that gear teeth can take that kind of a sudden impact load without immediately shearing off or prematurely failing in fatigue.

 

For a proper analysis, you really need to flesh out your design more.

[gcol]

Seems like a double rack and pinion in principle. Rack and pinion not meant to have intermittent engagement. Devil's own job to re-mesh smoothly once disengaged, and that is with unworn teeth. Undamped springs will limit the rpm range. Might work at low rpm, looks dodgy at moderate to high revs.

 

Normally a minimum of two and preferably three gear teeth required to be in constant mesh. You have from zero upwards.

 

Then there is the fixing of the steel rack inside the (aluminium?) piston. This must withstand heavy duty shocks, and problems with different thermal expansion causing warping and increase gear mesh inaccuracies, and also add undesirable weight to the piston. Always best to keep pistons to minimum weight, surely.

 

A quirky idea, might work with low temperature and low speed engine perhaps but I imagine the engineering costs would be high

[insane_alien]

the fabrication costs would be high and if it only had one set of teeth on the crank it wouldn't work. as gcol said, you'll need three.

 

also, i don't see it being advantageous over current methods. it looks prone to wear and tear, high costs, low torques, low rpms, and probably isn't so efficient.

[allmee]

Sorry forgot to add the gears.

[allmee]

A and B are front view and c is side view.

The system has to be setup with the one pistons teeth all ways on the crank shaft (8 pistons one of the pistons teeth should be connected(teeth for piston 1 are at the right side of the crank shaft teeth for 2 are at the bottom 3 are at the left side and four are at the top)).

c the gears should keep the pistons moveing at the same speed as the crank shaft.

[insane_alien]

looks prone to failure, i don't see an engine using this running for very long(couple of weeks maybe?) without needing maintenance. if it is an engine that gets started and stopped often then it will have a shorter lifespan.

[cjohnso0]

Assuming it works, what are the benefits of this over the standard crankshaft we all know and love? Along with a working design, this is a pretty important question.

[allmee]

[insane_alien]

well, you see, its not a matter of left to right energy, seeing as it is rotational. it still provides a torque on the driveshaft.