It is an opposed piston engine: a
cylinder and two oppositely reciprocating pistons form a combustion chamber; PatOP's unconventional geometry (pulling connecting rods) shifts the combustion to the slow dead center.
Starting with the Junkers-Doxford engine and replacing the lower piston and connecting rod by a piston and a connecting rod from the OPRE engine, the PatOP engine results.
The difference is:
1. Full balance of the inertia forces and moments of the single-cylinder two-piston PatOP basic module.
2. Zero total force on the crankshaft main bearings from both: the combustion loads and the inertia loads.
3. Additional time for the injection and the combustion of the fuel, that is higher revs, that is higher power density. At the lower revs this extra time improves the fuel efficiency and the clean exhaust.
4. More compact engine: the crown of the lower piston almost reaches the crankshaft.
5. Lubrication quality and mechanical friction equal to the "full" crosshead version of the Junkers-Doxford. The two-stroke PatOP engine has "four stroke like" lubrication.
6. For a given asymmetrical scavenging scheme it needs smaller crankpin offset (less vibration and friction).
7. Built-in volumetric scavenging pump of lower cost and friction.
With one photo per 20 crankshaft degrees (6 teeth on the flywheel) were created the above gif videos; there is also the video-animation PatOP.wmv and the 8MB controllable animation PatOP8.exe.
Bore: 79.5mm
Stroke: 64+64=128mm
Displacement: 635cc
Compression ratio: 17
Scavenging pump bore: 130mm (1.34 scavenging ratio)
Total engine height: 500mm
Total engine weight (without the flywheel): less than 20Kp
It is an:
opposed-piston,
two-stroke,
single-cylinder,
single-crankshaft,
full-balanced (vibration free),
cross-head,
direct-injection Diesel engine,
with built-in "volumetric" (for a wider rev range and flat torque curve) scavenging pump,
with four-stroke-like lubrication,
and with some 35% as compared to the conventional, or some 20% as compared to the Junkers-Doxford and to the OPOC of EcoMotors, additional time for the injection and combustion of the fuel.
The engine casing is free of any load except the power torque and the inertia torque.
The combustion liner is rid of thrust loads and only 20% longer than the total stroke.
Click on the following photos to enlarge:
Click on the photos below to enlarge:
The form of the combustion chamber at the CDC (Combustion Dead Center):
Click on the image below to download the PatOP1.MOV video (6.4MB QuickTime format),
or click here for the same youtube video,
of the 1st prototype PatOP engine running on Diesel fuel.
It is assembled with the gearbox of a Nissan Micra.
The engine is standing free on a desk.
Click on the image below to download the PatOP2.MOV video (9MB QuickTime format).
Click on the image below to download the PatOP1.wmv video (2.2MB windows wmv format).
The PatOP engine is a single crankshaft OPRE engine; the analysis of the OPRE engine covers the PatOP engine, too.
The compact PatOP V-4 engine (four-cylinder in 90 degrees Vee), animation at PatOP7.exe, has the same smoothness quality with the conventional V-8 engines: same number of power pulses per crank rotation and full balance of the inertia forces, of the inertia torques and of the inertia moments.
Along with the Junkers-Doxford, the Commer TS3 is another well-known single crankshaft opposed piston engine.
Click here to download the Commer TS gif animation, or click on the image above to download the controllable windows exe animation of the CommerTS.
PatOP ANIMATIONS
Click on the image below to download the
PatOP1.exe 1MB animation
Click on the image below to download the
PatOP2.exe 3MB animation
Click on the image below to download the
PatOP3.exe 6MB animation
Use the SpaceBar key to rotate the engine about its cylinder axis.
Click on the image below to download the
PatOP4.exe 2MB animation
Use the dot and the comma keys to control the animation.
Click on the image below to download the
PatOP5.exe 3MB animation
Use the dot and the comma keys to control the animation.
Click on the image below to download the
PatOP6.exe 3MB animation
Use the . , and the 1 2 3 4 5 6 keys to control the animation.
Click the image below for the
PatOP7.exe 5MB stereoscopic animation
Use the dot and the comma keys to control the animation.
Click the image below for the
PatOP8.exe 8MB animation
Use the SpaceBar, dot and comma keys to control the animation.
CrossHead PatOP (click here for a GIF animation (4MB):
Ports on the intake piston skirt cooperate with the intake ports / niches of the cylinder liner, eliminating the transfer pipes.
A reed valve traps the air into the scavenging cylinder; when the piston ports align with the liner ports, the scavenging begins.
The scavenge piston is ring-less; it has an elliptical / oval shape to compensate with the distance of the "intake crankpins" without overly increasing the scavenge piston area.
Immovable rings (seals) are in touch with the scavenge piston, keeping the lubricant at the crankcase side and the compressed air at the scavenging pump side; the scavenge cylinder needs not to match tightly with the scavenge piston.
The slippers bear the thrust loads.
The engine casing is a plate (cyan) wherein the unloaded main bearings of the crankshaft are secured.
The cylinder (comprising the sliders for the intake piston slippers) is also secured to the plate.
The oil pan, with the scavenging cylinder on it, is also secured to the plate.
TwinCharger CrossHead PatOP version (click here for a GIF animation (1MB):
The compressed air from the turbocharger goes to an air-cooler. The throttle valve (green) allows or stops the communication of the air-cooler with the space behind the intake piston.
When the turbocharger pressure is low (cranking, low revs, light loads etc) the throttle valve is kept closed, air enters through the one way (reed) valve into the scavenge cylinder and is trapped there for the scavenging.
When the turbocharger pressure increases, the throttle valve opens, the one way valve remains constantly closed (less noise, improved reliability) and the scavenging is made by exploiting the energy of the exhaust gas.
