Otto Four-Stroke Internal Combustion Cycle
US 194,047Intake, Compression, Power, and Exhaust Four-Stroke Cycle with Pre-Ignition Charge Compression
How It Works: Step-by-Step Mechanical & Physical Breakdown
The engine executes four distinct piston strokes across two full rotations of the crankshaft (): (1) **Intake Stroke** (): Piston moves down, sucking in stoichiometric fuel-air mixture through an intake valve; (2) **Compression Stroke** (): Valves close, piston moves up, compressing the mixture into a compact combustion chamber (); (3) **Power Stroke** (): Spark or flame ignites the dense compressed charge, driving in-cylinder pressure to and pushing the piston down with high force; (4) **Exhaust Stroke** (): Exhaust valve opens, piston moves up, sweeping spent combustion gases out the tailpipe. A half-speed camshaft geared at a ratio synchronizes the valve events.
Interactive Real-Time Physical Simulation
Detailed Component Architecture
12:1 Geared Half-Speed Camshaft / Slide-Valve Drive
Geared to the crankshaft by helical or bevel gears in an exact ratio (). The camshaft carries the intake slide-valve eccentric and the exhaust cam lobe, ensuring valve events occur once every two crank revolutions ().
2Closed-Chamber Pre-Ignition Compression Space
Clearance volume dimensioned to achieve a compression ratio . Pre-compressing the gas to raises charge density and accelerates chemical flame front propagation ().
3Slide-Valve Flame Ignition Port & Gas Injector
A cast-iron slide valve plate reciprocating across the cylinder head. A small internal pocket carries a burning town-gas pilot flame into direct communication with the pressurized combustion chamber at top dead center (), initiating rapid deflagration without electrical spark plugs.
4Dual Cast-Iron Inertial Flywheels
Two counter-balanced spoked cast-iron flywheels ( each) mounted on the crankshaft ends. The flywheel system stores of kinetic energy, driving the piston smoothly through the three non-power strokes (exhaust, intake, compression) with a coefficient of speed fluctuation .
5Poppet Exhaust Valve & Cam-Driven Rocker Arm
A mushroom-shaped forged steel poppet valve located in the cylinder bottom head. Combustion pressure () pushes the valve tighter against its conical iron seat; at crank angle, the half-speed cam lobe trips a pushrod rocker lever to unseat the valve against a coil spring, exhausting spent gases before bottom dead center.
Governing Equations & Colorized Principles
Air-Standard Otto Cycle Efficiency
Internal Combustion & 4-Stroke Otto Thermodynamic CycleThe governing physical relationship for describes how and system equilibrium and energy transfer according to first principles.
Crankshaft Speed
Adjusting Crankshaft Speed modulates real-time physical telemetry states and governing forces in the simulated mechanism.
The four distinct strokes (Intake, Compression, Power, Exhaust) compress the fuel-air charge prior to flame ignition, raising peak thermodynamic combustion temperature and work output.
Interactive Schematic Sheet (Fig. 1)
Cutaway drawing showing horizontal cylinder, piston, 2:1 side camshaft, slide-valve flame igniter, exhaust valve, and heavy flywheel.
Select Any Numbered Pin
Click pins on the schematic or select from the list below to inspect historical specifications.
Why It Still Matters
Nikolaus Otto's four-stroke cycle is the mechanical heart of modern global civilization. Virtually every gasoline car, truck, lawnmower, generator, and propeller-driven aircraft in existence operates on the four strokes (Intake, Compression, Power, Exhaust) patented by Otto in 1877. It made compact, high-power gasoline engines possible, enabling Gottlieb Daimler and Karl Benz to create the automobile.
Legal Claims Decoder (2 Numbered Claims)
The Historical Bottleneck
Why Prior Art Failed
- •Lenoir's 1860 engine ignited uncompressed gas at atmospheric pressure, losing most heat to water jackets.
- •Otto and Langen's earlier 1867 'free-piston' atmospheric engine was extremely noisy, rattling violently on a tall vertical rack.
- •French engineer Alphonse Beau de Rochas published a theoretical pamphlet in 1862 describing a four-stroke cycle but never built a working engine.