Topic: Spherical 4 stroke engine

[alltherightpills]

Saw this over on thekneeslider.com...

"Here’s a 4 stroke engine concept you have to see to understand, the Peraves Superballmotor uses a multipart sphere to replace the usual crankshaft, rods and pistons of a normal internal combustion engine.

The moving parts of the sphere have ceramic balls on their exterior which travel in grooves in the case surrounding the sphere. The rotating motion of the sphere causes the moving parts, which serve as pistons, to go through the 4 stroke cycle in 2 working chambers, which would be comparable to a 2 cylinder engine. Air and fuel are introduced at the sides near the rotating axis, are supercharged through the use of prechambers, flow into the gaps in the sphere created by the motion of the sphere, followed by compression, power and exhaust as you would expect. You have to watch the animation on their site to see the whole process because a description doesn’t work very well."

I don't know how much power this thing produces, but it looks pretty interesting.  Here is their website:

http://kugelmotor.peraves.ch/index_en.htm

[hoodellyhoo]

Interesting, but it seems like there is a lot of friction (the surface area of the ball) and sealing issues to deal with.

[Laminar]

My first thought is that there would be a significant amount of force on the guiding balls, and it would be hard to keep them from wearing out. Also, cooling would be difficult, since you can't have any kind of coolant running through the areas that see combustion directly, and because of their relatively large thickness, air cooling wouldn't be very effective.

But cool concept, it's neat to see someone thinking outside of the box.

[Tim.]

Not sure why the ceramic balls would be used vs some fancy cams etc. in the main crank shaft to control the movement of the 2 parts of the sphere.  I'd think they could be done away with.

Not sure how the sphere would be sealed against the motor housing to ensure good compression.'

Fun to look at anyhow.

[bucky katt]

looke like a great design for really high rpms

[themotoworks]

what are the benefits?  it seems like it would have the same benefits as a wankel engine... but is it any better?

[KB02]

I agree. Looks like a redesign of the wankle. Granted, I would love to see that Mazda RX8 engine shoehorned into a two wheeled chassis - It's not that big, it would fit rather nicely I would think.

I would like to see one of these Superball engines actually running. It would be interesting.

[Laminar]

I agree. Looks like a redesign of the wankle. Granted, I would love to see that Mazda RX8 engine shoehorned into a two wheeled chassis - It's not that big, it would fit rather nicely I would think.

I would like to see one of these Superball engines actually running. It would be interesting.

This one's pretty close

[mlinder]

The wankel has quite a bit less (actually, volumes less) friction than this spherical engine. the entire outside fo the sphere is in contact with the inside of the housing. Lot's and lots of friction there. The wankel has friction, for the most part, just at the apex of the rotor and the edges of the rotor against the combustion chamber wall.

[crazypj]

Cool animation, wonder if anyone will ever try and build it?
 Finally though, someone found a use for the guts from a Rubik's cube 
 Could have made it four chamber, still high friction but twice the power 

PJ

[alltherightpills]

Cool animation, wonder if anyone will ever try and build it?
 Finally though, someone found a use for the guts from a Rubik's cube 
 Could have made it four chamber, still high friction but twice the power 

PJ

They've made at least one, it's currently in a YP-400 scooter:

[Laminar]

The wankel has quite a bit less (actually, volumes less) friction than this spherical engine. the entire outside fo the sphere is in contact with the inside of the housing. Lot's and lots of friction there. The wankel has friction, for the most part, just at the apex of the rotor and the edges of the rotor against the combustion chamber wall.

Which is great until your apex seals fail at 70,000 miles and you need a new engine. 

[edbikerii]

Nah, just new seals.

The wankel has quite a bit less (actually, volumes less) friction than this spherical engine. the entire outside fo the sphere is in contact with the inside of the housing. Lot's and lots of friction there. The wankel has friction, for the most part, just at the apex of the rotor and the edges of the rotor against the combustion chamber wall.

Which is great until your apex seals fail at 70,000 miles and you need a new engine. 

[mlinder]

The wankel has quite a bit less (actually, volumes less) friction than this spherical engine. the entire outside fo the sphere is in contact with the inside of the housing. Lot's and lots of friction there. The wankel has friction, for the most part, just at the apex of the rotor and the edges of the rotor against the combustion chamber wall.

Which is great until your apex seals fail at 70,000 miles and you need a new engine. 

I wasn't commenting on longevity, but on efficiency. The more friction made, the more of the engines energy goes to just making the damn thing go.

[Gordon]

The wankel has quite a bit less (actually, volumes less) friction than this spherical engine. the entire outside fo the sphere is in contact with the inside of the housing. Lot's and lots of friction there. The wankel has friction, for the most part, just at the apex of the rotor and the edges of the rotor against the combustion chamber wall.

Which is great until your apex seals fail at 70,000 miles and you need a new engine. 

I wasn't commenting on longevity, but on efficiency. The more friction made, the more of the engines energy goes to just making the damn thing go.

Looks to me like the friction would be focused on the 4 ceramic balls.

[mlinder]

The wankel has quite a bit less (actually, volumes less) friction than this spherical engine. the entire outside fo the sphere is in contact with the inside of the housing. Lot's and lots of friction there. The wankel has friction, for the most part, just at the apex of the rotor and the edges of the rotor against the combustion chamber wall.

Which is great until your apex seals fail at 70,000 miles and you need a new engine. 

I wasn't commenting on longevity, but on efficiency. The more friction made, the more of the engines energy goes to just making the damn thing go.

Looks to me like the friction would be focused on the 4 ceramic balls.

The combustion chamber itself is sealed by the housing. The entire surface of the "piston" requires a tight seal al the way around, meaning the entire surface of the inner ball and the entire inside surface of the housing must be touching. That's a lot of surface.

[Laminar]

The combustion chamber itself is sealed by the housing. The entire surface of the "piston" requires a tight seal al the way around, meaning the entire surface of the inner ball and the entire inside surface of the housing must be touching. That's a lot of surface.

Not necessarily the entire ball, but probably just the silver parts in the animation. As long as those have a tight seal, the yellow parts don't have to touch.

[mlinder]

The combustion chamber itself is sealed by the housing. The entire surface of the "piston" requires a tight seal al the way around, meaning the entire surface of the inner ball and the entire inside surface of the housing must be touching. That's a lot of surface.

Not necessarily the entire ball, but probably just the silver parts in the animation. As long as those have a tight seal, the yellow parts don't have to touch.

Yeah, you have a point there, but I can't see how the silver parts there can keep a good seal over any length of time. Piston rings expand a bit with pressure, so even as they and the cylinder wall wear a bit, the 'flexibility' of piston rings will creata  good seal until they reach their wear limit. The silver bits in that animation do not appear to be able to expand to make up for wear.

[Laminar]

Yeah, you have a point there, but I can't see how the silver parts there can keep a good seal over any length of time. Piston rings expand a bit with pressure, so even as they and the cylinder wall wear a bit, the 'flexibility' of piston rings will creata  good seal until they reach their wear limit. The silver bits in that animation do not appear to be able to expand to make up for wear.

Agreed. I would like to see a video of it running and a better pictures of that dyno chart.