60 Fun Facts About Mechanical

How many classical simple machines were defined by Renaissance scientists?

Lever, wheel and axle, pulley, inclined plane, wedge and screw all multiply force by trading it against distance.

What is the fixed pivot point of a lever called?

Levers come in three classes depending on where fulcrum, load and effort sit.

The word 'lever' ultimately comes from a Latin adjective meaning what?

'Levis' also gave English the word 'light' as the opposite of heavy.

The earliest evidence of pulleys comes from Mesopotamia and which civilisation's Twelfth Dynasty?

The Greek mathematician Archytas of Tarentum later described the device.

A screw converts rotation into what kind of movement?

The smaller the pitch between threads, the greater the mechanical advantage.

Thomas Newcomen's atmospheric engine of 1712 was mainly used to do what?

It worked by condensing steam to make a partial vacuum, letting atmospheric pressure push the piston.

James Watt's improved steam engine roughly did what to the Newcomen engine's fuel efficiency?

Many existing atmospheric engines were converted to Watt's design, which is why Watt is the better-known name.

James Watt adopted the term 'horsepower' to compare his engines with what?

He measured a 'brewery horse' in 1782 and standardised the figure with Matthew Boulton the next year.

One imperial horsepower was standardised by Watt and Boulton as how many foot-pounds per minute?

The rounded constant 5252 in the torque-horsepower formula comes from dividing that figure by 2π.

Who first invented the centrifugal 'fly-ball' governor Watt added to engines in 1788?

Huygens used it to regulate windmills and water wheels a century earlier.

What are the four strokes of a four-stroke engine, in order?

The piston runs from top dead centre to bottom dead centre and back twice per cycle.

Which German engineer designed the first modern internal combustion engine, in 1876?

German engineering standards still define an 'Otto engine' as one ignited by a timed spark.

What ignites the fuel in a diesel engine?

That is why it is also called a compression-ignition engine.

As early as 1900, Rudolf Diesel ran his engines on which unusual fuel?

Biodiesel in modern compression-ignition engines is a return to his idea.

Rudolf Diesel was born in 1858 in which city?

His Bavarian parents ran a leather-goods business there; he delivered goods by barrow as a boy.

The Carnot cycle was proposed in 1824 by a physicist of which nationality?

Sadi Carnot's ideal cycle is fully reversible, shuttling heat between a hot and a cold reservoir.

A flywheel is a store of which kind of energy?

The stored energy scales with the square of its rotational speed; carbon-fibre versions spin to 60,000 rpm.

In a car, what does the differential allow the two wheels on a drive axle to do?

Mathematically, one shaft's speed is the average of the other two.

What does a crankshaft convert?

Its crankpins are driven by the pistons through connecting rods.

In a piston engine, what does the camshaft operate?

Its pointed cams turn rotation back into the up-and-down motion the valves need.

Which Greek letter usually represents torque in physics?

Engineers tend to say 'moment' where physicists say torque.

Who invented the modern steam turbine in 1884?

His Turbinia of 1894 was the first turbine-powered steamship and embarrassed the Royal Navy at a review.

Roughly what share of US electricity in 2022 was generated using steam turbines?

They sit at the heart of coal, gas, nuclear, geothermal and solar-thermal plants alike.

Which thermodynamic cycle describes an air-breathing jet engine?

A turbine-driven compressor feeds the combustor and the leftover energy exits as thrust.

Which English RAF officer co-created the turbojet, first run as a prototype in 1937?

Germany's Hans von Ohain built the first turbojet to actually fly.

The rotor of a Wankel engine is roughly the shape of what?

It spins inside a figure-eight-shaped housing, producing three power pulses per rotor revolution.

The hydraulic press, patented in 1795, is also known by the name of its inventor. Who?

He also developed the modern flush toilet, and studied fluid motion while installing them.

The hydraulic press works on a pressure principle named after which scientist?

Pressure is constant throughout a closed system, so a small piston can drive a much larger one.

Archimedes' screw was originally used to do what?

Run in reverse, modern versions act as small hydroelectric turbines at low-head sites.

The Antikythera mechanism was recovered from a shipwreck in which year?

Scans suggest it had 35 meshing bronze gears and could predict eclipses decades ahead.

What component distinguishes a Stirling engine from other closed-cycle hot-air engines?

Its inventor, Robert Stirling, was a Scottish clergyman.

Hooke's law states that the force needed to stretch a spring scales how with the distance?

The balance wheel in mechanical watches relies on it to keep a constant period.

Elisha Otis's 1853 invention did what?

He installed the first passenger safety elevator in a New York store in 1857.

Who installed the first working escalator, an 'inclined elevator', at Coney Island in 1896?

Seeberger later coined the word 'escalator' from the Latin scala and trademarked it in 1900.

Otis lost its exclusive right to the word 'escalator' in a 1950 case because the public saw it as what?

The case became a textbook warning about letting a trademark become generic.

The original Ferris Wheel was built as a landmark for which event?

George Washington Gale Ferris Jr. designed it; the tallest today is Ain Dubai at 250 metres.

What powers a turbocharger, as opposed to a supercharger?

Until the mid-20th century turbos were simply called turbosuperchargers.

Two or more meshing gears together are called what?

Gears with separate pegs inserted as teeth are properly called cogwheels.

Rack railways use a rack and pinion, with a toothed rack laid between the rails, to do what?

The same mechanism turns the wheel in most cars' steering and drives stairlifts and lock gates.

The universal joint is sometimes called a Cardan joint after which 16th-century polymath?

He also contributed to gimbals; the U-joint is famously not a constant-velocity joint.

In a ratchet, what is the pivoting catch that stops the gear turning backwards called?

The word ratchet is also slang for a ratcheting socket wrench.

Ball bearings cut friction because the balls do what instead of sliding?

At least two races contain the balls; usually one race is fixed and the other spins with the shaft.

The name of Hero of Alexandria's aeolipile comes from Aeolus, the Greek god of what?

The bladeless radial turbine spun on jets from a heated water container but was never a practical power source.

The horizontal or panemone windmill first appeared in the 9th century in which region?

The familiar vertical windmill only reached northwestern Europe in the 12th century.

The zipper takes its name from a 1923 brand of what?

Whitcomb Judson of Chicago had patented the original 'clasp locker' back in 1892.

Eli Whitney's 1793 cotton gin used what to pull cotton fibres through and separate them from seeds?

'Gin' is short for engine; the machine made cotton so profitable that it expanded slavery.

The first sewing machine is generally credited to which Englishman, in 1790?

Early machines were driven by a hand-turned flywheel or a foot treadle.

The first bush-roller chain patent, the basis of the bicycle chain, was filed in 1880 by which company?

Chain-driven bicycles like the 1879 Lawson and 1884 Starley Rover soon followed.

In a steam engine, what does steam pressure push back and forth inside the cylinder?

A connecting rod and crank then turn that back-and-forth push into rotation.

Who developed the first commercial steam-powered device, a water pump, in 1698?

It used condensing steam to create a vacuum that raised water, then steam pressure to lift it higher, but its lift height was very limited.

Which engineer built the first full-scale railway steam locomotive, hauling iron in Wales in 1804?

On 21 February 1804 it pulled 10 tonnes of iron, 70 passengers and five wagons along the Pen-y-darren tramway.

The American Society of Mechanical Engineers was founded in 1880 in response to what?

Robert Henry Thurston served as founding president, and the society has published Mechanical Engineering magazine since that year.

What is the largest ASME standard, both in size and in the number of volunteers who prepare it?

It covers design, fabrication, inspection and care of boilers, pressure vessels and even nuclear components.

Which more economical steam-generator design took over for marine use in the late 1800s?

Fire-tube boilers stayed standard on steam locomotives, where hot gas passes through tubes immersed in water.

What was the name of the final experimental locomotive of 1808 built by the Pen-y-darren pioneer?

Four years later Matthew Murray's twin-cylinder Salamanca ran on the rack-and-pinion Middleton Railway.

Arthur Woolf's 1805 patent covered which kind of steam engine, later near-universal at sea?

High-pressure steam expands in one cylinder and then again in one or more larger low-pressure cylinders.

Which Chinese polymath of the 2nd century AD improved a water clock and invented a seismometer?

Ma Jun followed a century later with a chariot fitted with differential gears, and Su Song built an astronomical clock tower.

In which year did Al-Jazari write his Book of Knowledge of Ingenious Mechanical Devices?

He was one of many Islamic Golden Age inventors; the worm-gear roller cotton gin also appeared in the Delhi Sultanate era.

Whose 1849 four-valve engine did the Rumford Medal committee call the greatest advance since Watt?

Its separate admission and exhaust valves and automatic variable cutoff made it the acme of the horizontal engine.

Which Spanish inventor patented the first steam-powered water pump for draining mines in 1606?

Della Porta had described a steam apparatus for raising water in 1601, and Branca a rudimentary turbine in 1629.