Machines & Mechanical Systems
How physical mechanisms transform energy into work: mechanical advantage, hydraulic fluid power, internal combustion engines, refrigeration cycles, and electric motors.
Pieces in this series
How Gears and Mechanical Advantage Work
From Archimedes' levers and block-and-tackle pulleys to involute gear tooth profiles, planetary gearboxes, and the automotive differential
Machines cannot create energy; they trade force for displacement under conservation of work. Around 250 BCE, Archimedes formulated the law of the lever, which rotary mechanics transformed into pulleys, winches, and gears. By using Euler's…
How Hydraulic Systems Multiply Force
From Pascal's fluid incompressibility and hydrostatic pressure transmission to spool valves, hydraulic cylinders, and aircraft fly-by-wire actuators
Hydraulic systems transmit immense mechanical power through enclosed incompressible fluids. Under Pascal's principle, pressure applied to a fluid transmits undiminished in all directions. Because force equals pressure times area, a modest…
How Internal Combustion Engines Work
From the four-stroke Otto cycle and air-fuel stoichiometry to deflagration flame fronts, slider-crank kinematics, and thermodynamic Carnot limits
Liquid hydrocarbons pack an energy density of 45 MJ/kg. In 1876, Nikolaus Otto perfected the four-stroke engine cycle: Intake, Compression, Power, and Exhaust. Expanding 2,500°C combustion gases push pistons downward, which crankshafts…
How Refrigerators and Heat Pumps Work
From the Clausius thermodynamic statement and vapor-compression cycles to phase-change latent heat, expansion valves, and reversible heating coefficients
Heat spontaneously flows only from hotter bodies to colder ones. Refrigerators and heat pumps move thermal energy uphill against this gradient by inputting mechanical work. Operating a four-stage closed vapor-compression cycle—evaporator…
How Electric Motors Work
From Lorentz magnetic forces and DC mechanical commutators to Tesla's rotating AC magnetic field, induction slip, and brushless electronic switching
Electric motors convert electrical energy into mechanical torque with >95% efficiency, operating on the Lorentz magnetic deflection of moving charges. In DC motors, mechanical commutators alternate polarity to sustain rotation. In…
How Steam Turbines and Generators Produce Electricity
How steam turbines and synchronous AC generators convert high-pressure steam into 50/60 Hz three-phase electricity via Rankine expansion and Faraday induction
Over 60% of global electricity is generated by steam turbines coupled to synchronous electromagnetic generators. Operating on the Rankine cycle, purified water is boiled at 250 atmospheres and superheated to 600°C. Expanding through…
How Jet Engines and Gas Turbines Actually Work
The continuous Brayton cycle, multi-spool axial compression, single-crystal superalloys, film cooling, and high-bypass turbofan thrust
Reciprocating aircraft pistons hit physical ceilings in thin air. Jet engines replaced reciprocating friction with the continuous fluid flow of the Brayton thermodynamic cycle. In high-bypass turbofans, titanium fans suck in tons of air…
How Airplane Wings Actually Generate Lift
The equal-transit fallacy, the Kutta condition, bound circulation, Bernoulli pressure gradients, and Newtonian downwash momentum
The popular 'equal transit time' explanation of flight is physically impossible. An airfoil generates lift through air viscosity, boundary layer dynamics, streamline curvature, and the Kutta condition. As the wing moves, induced bound…
How Electrical Transformers Step Voltage Up and Down
Faraday mutual induction, magnetic flux linkage, laminated silicon steel cores, and the physical mechanics of long-distance power grids
Long-distance power transmission battles resistive heat loss ($P = I^2 R$). To transmit power across continents, transformers step voltage up to hundreds of thousands of volts, reducing current to a trickle. Operating with zero moving…
How Does Photolithography Print Billions of Transistors on a Silicon Wafer?
How extreme ultraviolet laser-produced plasma, Bragg mirror optics, and nanometer photoresists print 50 billion transistors on silicon.
Modern microchips pack over 50 billion transistors into a thumbnail-sized silicon die, with gates under 20 nanometers wide. Photolithography uses light as a precision chisel to pattern these features. By firing pulsed lasers at falling…
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