Frequently Asked Question:

1. The pivoting straightedges will see high acceleration forces as they have to change direction of movement

Forces are lower than in reciprocating piston engines.

The forces on a piston and conrod of a reciprocating piston engine see much more and different stresses and strains. The orbox piston acts like a very large gear tooth on the pivoting bodies. The forces are thus allowed to be very large. Some highschool calculus shows these forces are acceptable even at high speeds. High speeds are usually limited by pumping losses, which increase exponentially as the gas speed nears the speed of sound. Larger input ports allow lower gas speeds. Thus higher engine speed and more power can be generated than with reciprocating engines with valves.

2. The pivoting motion will create high vibration.

Not if you balance properly.

A one-cylinder reciprocating piston engine does create a lot of vibration, which is why most engines have more cylinders. Considering both rotor and pivoting bodies well balanced on their axes, vibrations will not be linear but rotational. And similarly to reciprocating engines, these torsional vibrations can be dampened by counter-rotating weights, by absorbers in the crankshaft or on the housing. Or by adding two, or more, orbox modules. But there is more to it:

The rotor provides torque to accelerate and decelerate the pivoting bodies, and the net torque is centered around the rotor axis. To keep the pivoting bodies in place, the bearings do see forces, which do create torque on the housing. This torque can be determined considering conservation of angular momentum. By deliberately unbalancing the pivoting bodies, by removing weight from the outer side, a net mass is accellerated back and forward. These inertia forces can compensate the pivoting torque on the housing. So the net torque on the housing is (almost) zero.

3. Why are there "secundary seals"? Aren't the primary seals good enough?

Well, the top seal pushes down the side seals towards the bottom housing, so that's pretty tight*. But the side seals get backpressured by combustion gasses (if not hydraulically or otherwise). Seals only work betwee two items at a time, so to prevent the gasses BEHIND the seal to leak, there are additonal seals (as shown in the animations). Of course more seals are better anyway to contain pressures (like in piston engines), but friction limits the amount and size of seals economically viable.

*altenatively, the side seals can be split along their long axis, at an angle, creating a wedge, guaranteeing sealing also with a fixed top seal, that is not pressed down.

4. Surely, if this would be any good, someone would have come up with it before.

Considering all the crackpot ideas, and weekly patent registrations for "new" engines, this is exactly what we thought. This geometric law was known by the old Egyptians, but apparently never very known or considered practical. And not until we investigated, and could not find anybody using this simple geometric law, did we think we could be on to something. Working out the details, considering the possible advantages, and not being able to find serious drawbacks, just got us to where we are today.