Rotary Piston

[MRC_Hans]

Whoops .... it works !

I'm sure it works. It is a very nicely made prototype. However, it has a lot of moving interfaces, of several different shapes. To keep it tight, you need extremely precise engineering, and even then you will get a lot of friction.

Hans

 

[Emil]

(I'm writing short sentences that should work in google translate) (what is your native language?)

Romanian.

I understand the principle in your video. It can work as a pump. Similar constructions already exist.

It could also be a motor, such motors are used in pneumatic tools.

It is not a new invention.

The summary of the patent:

The invention relates to a rotary machine with eccentric piston, that can be a pump, compressor, pneumatic motor, hydraulic motor or internal combustion engine. According to the invention, the rotary machine has a cylindrical piston (1) mounted in a cylindrical housing (2) tangent to the inner cylindrical wall of the cylindrical housing (2), the cylindrical piston (1) being provided with a sealing piece (3), wherein a rotary blade (4) can glide, said blade being integral with a driving shaft (5) whose rotation axis concides with the axis of the cylindrical housing (2), the rotary blade (4) being in permanent contact with the inner cylindrical wall of the cylindrical housing (2); between the rotation axis of the cylindrical piston (1) and the axis of the cylindrical housing (2) there is provided an eccentricity (e).

The patent

Now about Wankel engines. As somebody allready mentioned, Masda have been using it, Reneault too, so obviously it was not killed by GM. Instead, it became opsolete. You see, it is not possible ot get a very high compression ratio with an Wankel (or any other rotary type engine, for that matter), and this means that you cannot get a really good fuel economy.

The engine, which can be achieved with rotary piston is not a four-stroke engine (Otto or Diesel).
But leave the engine and to insist as a pump or hydraulic motor.

I'm sure it works. It is a very nicely made prototype. However, it has a lot of moving interfaces, of several different shapes. To keep it tight, you need extremely precise engineering

As seen in the second video, there are only six parts.
Is much easier to execute than a Wankel engine.

...and even then you will get a lot of friction.
Hans

I do not have the same opinion.
In your opinion, where the friction occurs? (Let's call stator (cylindrical housing), rotor (cylindrical piston), axis (driving shaft ), blade (rotary blade) and pass element (sealing piece).)

 

[wlminex]

Emil: Sometime, elsewhere (PM?), I'd like to chat with you re: my linear engine . . . never got it beyond the design-drawing stage . . . but it is 'scalable; from the size of a fountain pen to heavy-duty applications . . . wlminex

 

[MRC_Hans]

RThe engine, which can be achieved with rotary piston is not a four-stroke engine (Otto or Diesel).
But leave the engine and to insist as a pump or hydraulic motor.

I think it will be essentially four stroke, but ... nevermind.

As seen in the second video, there are only six parts.
Is much easier to execute than a Wankel engine.

A Wankel engine, in principle, has only three moving parts.

I do not have the same opinion.
In your opinion, where the friction occurs? (Let's call stator (cylindrical housing), rotor (cylindrical piston), axis (driving shaft ), blade (rotary blade) and pass element (sealing piece).)

You have friction between:

- stator and blade (both cylinder wall and endpieces)
- blade and sealing piece
- sealing piece and rotor
- sealing piece and stator (endpieces)
- rotor and stator (endpieces)

And exactly all these interfaces have to be air tight.

Another problem is that you have an uneven load on the axis (because there is only one blade).

Remember that you will need to keep those interfaces airtight over a considerable temperature range (even if you don't use it as an engine).

I am not saying that your device cannot work. I am saying that it has no advantage over existing systems.

 

[Emil]

I think it will be essentially four stroke, but ... nevermind.

There is a continuous burning and not one sequential.

A Wankel engine, in principle, has only three moving parts.

Compare Wankel with Rotary Piston.

[video=youtube;MrbDU_n1jqM]http://www.youtube.com/watch?v=MrbDU_n1jqM[/video]

At Wankel, contact between rotor and stator is a line (the generator).
At rotary piston, contact between rotor and stator is on a surface and no need to rub. Similarly, between blade and stator, contact is on a surface and no need to rub.

If you should make a hydraulic transmission of torque, what do you do?

You have friction between:

- stator and blade (both cylinder wall and endpieces)
- blade and sealing piece
- sealing piece and rotor
- sealing piece and stator (endpieces)
- rotor and stator (endpieces)

-no, forces are taken by the bearing and no need to rub
-yes, but forces are insignificant
-yes, but forces are insignificant
-I do not understand, they are not into contact.
-no, forces are taken by the bearing and no need to rub

And exactly all these interfaces have to be air tight.

Yes, if used as a compressor or pneumatic motor.

Another problem is that you have an uneven load on the axis (because there is only one blade).

Yes, must be balanced and linearized using different methods. (This is just the principle and require engineering.)

Remember that you will need to keep those interfaces airtight over a considerable temperature range (even if you don't use it as an engine).

Yes indeed, but as there isn't a four-stroke engine and it has separat combustion chamber, temperature differences are small.

I am not saying that your device cannot work. I am saying that it has no advantage over existing systems.

It was awarded with gold medals since it was considered better than existing ones so far.

 

[kaduseus]

That's a really nice design Emil.
If you consider the cost of making a simple water pump, what lift (height of water) do you think you could obtain with a rotary pump based on your design at the same cost?
You can calculate this on air pressure, a cheap pump will create a 2 atmosphere vacuum to draw the water.

Have you ever looked at designing a 5 piston wankel engine?
(instead of triangle piston it is pentagon, and instead of 2 chambers there are 4)
I reckon you could even run a 5 piston wankel as a 3 stroke by changing the ignition sequence.

 

[Emil]

That's a really nice design Emil.

Thank you.

If you consider the cost of making a simple water pump, what lift (height of water) do you think you could obtain with a rotary pump based on your design at the same cost?

From the hydraulic point of view is unlimited. Is limited only constructively as a classic piston.

You can calculate this on air pressure, a cheap pump will create a 2 atmosphere vacuum to draw the water.

I do not understand, how can you create "2 atmosphere vacuum" ?

Have you ever looked at designing a 5 piston wankel engine?
(instead of triangle piston it is pentagon, and instead of 2 chambers there are 4)

Yes, and I think you wanted to write instead of 3 chambers there are 5.

I reckon you could even run a 5 piston wankel as a 3 stroke by changing the ignition sequence.

I do not know how 3 stroke engine work. I've never heard of 3 stroke engine.

 

[kaduseus]

To suck water up a pipe you need a vacuum, atmosphere is 14.7 psi pushing down on water, so 1 atmosphere vacuum is 0 psi and 2 atmosphere vacuum is -14.7 psi.
I think that's right, so you would just need to test amount of air pressure at psi your pump can produce, as it will probably create that in vacuum psi.
A 1 atmosphere pump can lift about ~3.5 meters of water, 2 atmospheres can lift ~7 meters of water.

Yeah technically it is 5 chamber, I meant the shape of the outside part, wankel is 2 round bits, I meant 4 round bits.
Made you a piccy anyway to show you.

Got another that uses a square piston with 3 round bits to the outside part.

3 stroke just means it runs as 2 stroke but misses sequence sometimes to save fuel.
It might be 5 stroke if it runs as 4 stroke and misses sequence sometimes.
Like the Cadillac Sixteen that turns off up to 12 cylinders to save fuel.

 

[Emil]

kaduseus,
LOL...1 Atm(1kgf/cm²)=0 psi(0 pounds-force per square inch)...LOL

I have not seen so many in so few words.
Your ingenuity knows no boundaries. I give up. :truce:

 

[kaduseus]

LOL - just hook your device to a tyre pressure guage
Hand digging a 20ft well for my father so became a 15 minute wiki expert in pumps.
I've seen alot of pump designs, not seen yours anywhere.
I really like that design you have, simple but effective, a bit like the semi-rotary hand pump but better because you could hook it up to a bicycle, or a windmill, and looks like it would produce alot more pressure than the standard rotary hand pumps.

Ingenuity? I thought everyone knew the principles of the wankel engine?
It's all in the gear ratios.

The 4 face wankel

The 5 face animated.
(you know you want to build one )

 

[DaS Energy]

Hello Emil,

A genuine good luck with your work. Going from post concept to final model is never an easy task.

I do not wish to take from your post. You being a mechanical engineer may see the benefits of different form of rotory piston.
Your engineering skills I trust would have little difficulty in assembling.
All assistance provided. I now too old and too tired for continuation.

http://i1225.photobucket.com/albums/ee397/DaSEnergy/Untitled-1.png

Cheers Peter