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Frank -

Originally Posted by Frank Lee

I couldn't see anything that explains wth is going on in there

I don't understand it but I found the FAQ :

RBR - Radial Bi Rotary by Devaere Franky

Where is the name RBR-engine coming from?

RBR-engine stands for Radial Bi Rotary - Balanced Piston Combustion Engine.

Rotary and radial engines look strikingly similar when they are not running and can easily be confused, since both have cylinders arranged radially and pointing outward around a central crankshaft.

There are two major types of rotary engines. The pistonless rotary engine like a Wankel engine and the rotary engine with pistons. Piston rotary engines have a stationary crankshaft and the entire cylinder block rotates around it.
( ex. Gnome et Rhône )
Radial engines use a rotating crankshaft in a fixed engine block,

In a bi-rotary piston engine however, the crankshaft rotates also, as in a radial ,and the cylinders are geared to turn in the opposite direction as in a rotary. ( ex. Siemens-Halske_Sh.III )
Another kind of bi-rotary engines is a configuration with "open topped " cylinders. Surrounding them is a fixed ring in which are placed alternating inlet port, spark plug, and exhaust port openings. Plates at the front and rear of this ring provide bearings for the shaft, accessory attachments, engine mounting points, etc. The engine has no expensive valve train but still operates on the four-stroke principal (inlet, compression, power, exhaust) by sequentially presenting the open top cylinders to the relevant areas of the head-ring.( example Mawen Engine and this RBR Engine)

Three key factors contributed to the rotary engines success :
* Smooth running: Rotaries delivere power very smoothly because the relatively large rotating mass of the cylinders acting as a flywheel.
* Weight advantage: many conventional engines had to have heavy flywheels added to smooth out power impulses and reduce vibration. Rotary engines gained a substantial power-to-weight ratio advantage by having no need for an added flywheel.
* Improved cooling: when the engine was running the rotating cylinder block created its own fast-moving cooling airflow, even with the engine stationary.

Why is this a balanced engine ?
Engine balance is the design, construction and tuning of an engine to run smoothly. Improving engine balance reduces vibration and other stresses and, within a respectable percentage, improves the overall performance, efficiency, cost of ownership and reliability of the engine, as well as reducing the stress on other machinery near the engine.
This is a naturally smooth engine design, because all rotatings and reciprocating parts are equalized with each other , without creating any rocking couple or torsional vibrations.

What about the top-seals compared to Wankel's apex-seals ?
Wankel suffers from scatter marks in the rotorhouse, caused by the vibrating and oil consuming apex-seals. The Wankel also suffers from high fuel-consumption caused by the non ideal combustion chambre and has difficulties to cope with emissions regulations. ( Mazda RX8 is no longer allowed in Europe ).
The RBR-engine has 12 ignitions per rotor revolution. Wankel has 3 ignitions.
Therefore the rotor 's revolution is 4 times slower than a Wankel , having thus less friction. The top-rings are no-oil-consuming seal-rings of a more conventional piston-ring shape.

What about gyroscopic effect in case of use for aviation ?
This engine has a bonus ,the counter-rotating masses tend to cancel out the gyroscopic forces of the engine. This is achieved by using a planetary gearhouse in the rear of the crankcase.

What about propeller efficiency in case of use for aviation ?
Because of the reduction gearing effect ( 1/5 ) of the engine effectively running at for instance 5000 rpm for only 1000 rpm of the airscrew directly connected to the crankshaft, there is a increased propeller efficiency.

Is this engine suited for generators or green technology hybrides ?
Cylinderbank and crankshaft has a 1 to 5 ratio. This means that a engine ideal designed and running at a fix full throttle has very interesting rpm-configurations.
A crankshaft running at 3000 rpm has the cylinder rotor running at 600 rpm, 6000 rpm crankshaft correspond with 1200 rpm cylinderrotor. These are all very interesting AC-electromotor rpm's.

Is this engine easy to build ?
This engine is build with standard parts machined on presently known standard machines. The engine parts are simply re-arranged. A You-tube search is showing a lot of hobbyst building small radial and rotary engines . This one is even without valvetrain and yet a 4 stroke.
Here ar two examples of my favorites.
Jerry Hale's special rotary engine
Homemade radial engine

Re-boost Plastic automotive engine ?
Although this engine has a very interesting power to weight ratio , it is to be considered that voluminous parts ( ex. bearing houses ) can be built out of Torlon thermoplastic, a material that has properties that out-perform all but the most exotic composites and polymers. A plastic Cosworth engine raced succesfully in the International Motor Sports Association's Camel GT Championship.

What about the Atkinson cycle ?
The Atkinson cycle is designed to provide efficiency at the expense of power density, and is used in some modern hybrid electric applications. In a Atkinson cylce the power stroke is longer than its compression stroke, therefore the engine can achieve greater thermal efficiency than a traditional otto-cycle engine. This can be achieved in the RBR-engine by longering the inletgates on the fixed outerring to shorten the compression stroke.

EGR Valve ?
The engine can easely be provided with a EGR valve. The inlet and outlet gates are positioned close to each other. The EGR valve helps the engine more efficiently and completely burn fuel by recirculating a portion of exhaust and running it through the combustion process again. This results in a cooler, more complete burn of the fuel which decreases noxious emissions by prohibiting the formation of some harmful gases.

CarloSW2