A crankshaft is a mechanical component used in a
piston engine
A reciprocating engine, also often known as a piston engine, is typically a heat engine that uses one or more reciprocating pistons to convert high temperature and high pressure into a rotating motion. This article describes the common featu ...
to convert the
reciprocating motion
Reciprocating motion, also called reciprocation, is a repetitive up-and-down or back-and-forth linear motion. It is found in a wide range of mechanisms, including reciprocating engines and pumps. The two opposite motions that comprise a single r ...
into
rotational motion
Rotation, or spin, is the circular movement of an object around a '' central axis''. A two-dimensional rotating object has only one possible central axis and can rotate in either a clockwise or counterclockwise direction. A three-dimensional ...
. The crankshaft is a rotating
shaft containing one or more
crankpin
A crankpin or crank pin, also known as a rod bearing journal, is a mechanical device in an engine which connects the crankshaft to the connecting rod for each cylinder. It has a cylindrical surface, to allow the crankpin to rotate relative to the ...
s,
that are driven by the
piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...
s via the
connecting rod
A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksh ...
s.
The crankpins are also called ''rod bearing journals'', and they rotate within the "big end" of the connecting rods.
Most modern crankshafts are located in the
engine block
In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was atta ...
. They are made from
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
or
cast iron
Cast iron is a class of iron–carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impuriti ...
, using either a
forging
Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at which i ...
,
casting
Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...
or
machining
Machining is a process in which a material (often metal) is cut to a desired final shape and size by a controlled material-removal process. The processes that have this common theme are collectively called subtractive manufacturing, which utilizes ...
process.
Design
![Cad crank](https://upload.wikimedia.org/wikipedia/commons/d/dc/Cad_crank.jpg)
The crankshaft located within the
engine block
In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was atta ...
, held in place via
main bearing
Main may refer to:
Geography
* Main River (disambiguation)
**Most commonly the Main (river) in Germany
* Main, Iran, a village in Fars Province
*"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries
...
s which allow the crankshaft to rotate within the block. The up-down motion of each piston is transferred to the crankshaft via
connecting rods
A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksha ...
. A
flywheel
A flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, ass ...
is often attached to one end of the crankshaft, in order to smoothen the power delivery and reduce vibration.
A crankshaft is subjected to enormous stresses, in some cases more than per cylinder. Crankshafts for
single-cylinder engine
A single-cylinder engine, sometimes called a thumper, is a piston engine with one cylinder. This engine is often used for motorcycles, motor scooters, go-karts, all-terrain vehicles, radio-controlled vehicles, portable tools and garden machinery ...
s are usually a simpler design than for engines with multiple cylinders.
Bearings
The crankshaft is able to rotate in the engine block due to the 'main bearings'. Since the crankshaft is subject to large horizontal and torsional forces from each cylinder, these main bearings are located at various points along the crankshaft, rather than just one at each end. The number of main bearings is determined based on the overall load factor and the maximum engine speed. Crankshafts in diesel engines often use a main bearing between every cylinder and at both ends of the crankshaft, due to the high forces of combustion present.
Flexing of the crankshaft was a factor in
V8 engine
A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration.
The first V8 engine was produced by the French Antoinette company in 1904, developed and us ...
s replacing
straight-eight engine
The straight-eight engine (also referred to as an inline-eight engine; abbreviated I8 or L8) is a piston engine with eight cylinders arranged in a straight line along the crankshaft. The number of cylinders and perfect primary and secondary engi ...
s in the 1950s; the long crankshafts of the latter suffered from an unacceptable amount of flex when engine designers began using higher
compression ratio
The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values.
A fundamental specification for such engines, it is measured two ways: the stati ...
s and higher engine speeds (RPM).
Piston stroke
The distance between the axis of the crankpins and the axis of the crankshaft determines the
stroke length of the engine.
Most modern car engines are classified as "over square" or short-stroke, wherein the stroke is less than the diameter of the
cylinder bore
In a piston engine, the bore (or cylinder bore) is the diameter of each cylinder.
Engine displacement is calculated based on bore, stroke length and the number of cylinders:
displacement =
The stroke ratio, determined by dividing the bore by ...
. A common way to increase the low-RPM torque of an engine is to increase the stroke, sometimes known as "stroking" the engine. Historically, the trade-off for a long-stroke engine was a lower rev limit and increased vibration at high RPM, due to the increased piston velocity.
Cross-plane and flat-plane configurations
When designing an engine, the crankshaft configuration is closely related to the engine's
firing order
The firing order of an internal combustion engine is the sequence of ignition for the cylinders.
In a spark ignition (e.g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated. In a diesel engi ...
.
Most production V8 engines (such as the
Ford Modular engine
The Ford Modular engine is Ford Motor Company's overhead camshaft (OHC) V8 and V10 gasoline-powered small block engine family. Despite popular belief that the Modular engine family received its moniker from the sharing of engine parts across num ...
and the
General Motors LS engine
"LS engine" is the colloquial name given to the third and fourth generation small-block V8 gasoline engine used in General Motors' vehicles. The name evolved from the need to differentiate the Gen 3/Gen 4 small blocks from the original Gen 1/ ...
) use a
cross-plane crank whereby the crank throws are spaced 90° apart. However, some high-performance V8 engines (such as the
Ferrari 488
The Ferrari 488 (Type F142M) is a mid-engine sports car produced by the Italian automobile manufacturer Ferrari. The car replaced the 458, being the first mid-engine Ferrari to use a turbocharged V8 since the F40. It was succeeded by the Ferra ...
) instead use a
flat-plane crank
The flat-plane crank (sometimes flatplane) is a type of crankshaft for use in internal combustion engines that has a 180 degree angle between crank throws.
Details
Flat-plane cranks are used in V-configuration engines, generally with eight ...
, whereby the throws are spaced 180° apart, which essentially results in two inline-four engines sharing a common crankcase. Flat-plane engines are usually able to operate at higher RPM, however they have higher second-order vibrations, so they are better suited to racing car engines.
Engine balance
For some engines it is necessary to provide
counterweight
A counterweight is a weight that, by applying an opposite force, provides balance and stability of a mechanical system. The purpose of a counterweight is to make lifting the load faster and more efficient, which saves energy and causes less wear ...
s for the reciprocating mass of the piston, conrods and crankshaft, in order to improve the
engine balance
Engine balance refers to how the forces (resulting from combustion or rotating/reciprocating components) are balanced within an internal combustion engine or steam engine. The most commonly used terms are ''primary balance'' and ''secondary bal ...
. These counterweights are typically cast as part of the crankshaft but, occasionally, are bolt-on pieces.
Flying arms
![Crankshaft jap grayscale](https://upload.wikimedia.org/wikipedia/commons/7/79/Crankshaft_jap_grayscale.jpg)
In some engines, the crankshaft contains direct links between adjacent crank pins, without the usual intermediate main bearing. These links are called ''flying arms''.
This arrangement is sometimes used in
V6 and
V8 engine
A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration.
The first V8 engine was produced by the French Antoinette company in 1904, developed and us ...
s, in order to maintain an even firing interval while using different V angles, and to reduce the number of main bearings required. The downside of flying arms is that the rigidity of the crankshaft is reduced, which can cause problems at high RPM or high power outputs.
Counter-rotating crankshafts
In most engines, each connecting rod is attached a single crankshaft, which results in the angle of the connecting rod varying as the piston moves through its stroke. This variation in angle pushes the pistons against the cylinder wall, which causes friction between the piston and cylinder wall. To prevent this, some early engines - such as the 1900-1904
Lanchester Engine Company flat-twin engines - connected each piston to two crankshafts that are rotating in opposite directions. This arrangement cancels out the lateral forces and reduces the requirement for counterweights. This design is rarely used, however a similar principle applies to
balance shaft
Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The counter balance shafts have eccentric weights and rotate in opposite direction to each other, which generates a net vertical force.
Th ...
s, which are occasionally used.
Construction
Forged crankshafts
![IPH Kurbelwelle](https://upload.wikimedia.org/wikipedia/commons/5/5f/IPH_Kurbelwelle.jpg)
Crankshafts can be created from a steel bar using
roll forging. Today, manufacturers tend to favour the use of forged crankshafts due to their lighter weight, more compact dimensions and better inherent damping. With forged crankshafts,
vanadium
Vanadium is a chemical element with the symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer ( pas ...
micro-alloyed steels are mainly used as these steels can be air-cooled after reaching high strengths without additional heat treatment, except for the surface hardening of the bearing surfaces. The low alloy content also makes the material cheaper than high alloy steels. Carbon steels also require additional heat treatment to reach the desired properties.
Cast crankshafts
Another construction method is to
cast
Cast may refer to:
Music
* Cast (band), an English alternative rock band
* Cast (Mexican band), a progressive Mexican rock band
* The Cast, a Scottish musical duo: Mairi Campbell and Dave Francis
* ''Cast'', a 2012 album by Trespassers William
* ...
the crankshaft from ductile. Cast iron crankshafts are today mostly found in cheaper production engines where the loads are lower.
Machined crankshafts
Crankshafts can also be
machined
Machining is a process in which a material (often metal) is cut to a desired final shape and size by a controlled material-removal process. The processes that have this common theme are collectively called subtractive manufacturing, which utilizes ...
from
billet
A billet is a living-quarters to which a soldier is assigned to sleep. Historically, a billet was a private dwelling that was required to accept the soldier.
Soldiers are generally billeted in barracks or garrisons when not on combat duty, alth ...
, often a bar of high quality vacuum remelted steel. Though the fiber flow (local inhomogeneities of the material's chemical composition generated during casting) does not follow the shape of the crankshaft (which is undesirable), this is usually not a problem since higher quality steels, which normally are difficult to forge, can be used. Per unit, these crankshafts tend to be very expensive due to the large amount of material that must be removed with lathes and milling machines, the high material cost, and the additional heat treatment required. However, since no expensive tooling is needed, this production method allows small production runs without high up-front costs.
History
China
![Bundesarchiv Bild 135-BB-152-11, Tibetexpedition, Tibeter mit Handmühle](https://upload.wikimedia.org/wikipedia/commons/7/72/Bundesarchiv_Bild_135-BB-152-11%2C_Tibetexpedition%2C_Tibeter_mit_Handm%C3%BChle.jpg)
The earliest hand-operated
cranks appeared in China during the
Han Dynasty
The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...
(202 BC-220 AD). They were used for silk-reeling, hemp-spinning, for the agricultural
winnowing
Winnowing is a process by which chaff is separated from grain. It can also be used to remove pests from stored grain. Winnowing usually follows threshing in grain preparation. In its simplest form, it involves throwing the mixture into the ...
fan, in the water-powered flour-sifter, for hydraulic-powered metallurgic
bellows
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtigh ...
, and in the well
windlass
The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound arou ...
.
The rotary winnowing fan greatly increased the efficiency of separating grain from husks and stalks. However, the potential of the crank of converting circular motion into reciprocal motion never seems to have been fully realized in China, and the crank was typically absent from such machines until the turn of the 20th century.
Europe
![Roman crank handle, Augusta Raurica, Switzerland](https://upload.wikimedia.org/wikipedia/commons/e/e1/Roman_crank_handle%2C_Augusta_Raurica%2C_Switzerland._Pic_01.jpg)
A crank in the form of an eccentrically-mounted handle of the rotary
handmill appeared in 5th century BC
Celtiberian Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
and ultimately spread across the
Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterr ...
.
A Roman iron crank dating to the 2nd century AD was excavated in
Augusta Raurica
Augusta Raurica is a Roman archaeological site and an open-air museum in Switzerland located on the south bank of the Rhine river about 20 km east of Basel near the villages of Augst and Kaiseraugst. It is the site of the oldest known Roma ...
,
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
.
The crank-operated
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a letter ...
mill is dated to the late 2nd century.
![Römische Sägemühle](https://upload.wikimedia.org/wikipedia/commons/b/b3/R%C3%B6mische_S%C3%A4gem%C3%BChle.svg)
Evidence for the crank combined with a connecting rod appears in the
Hierapolis mill
The Hierapolis sawmill was a Roman water-powered stone sawmill at Hierapolis, Asia Minor (modern-day Turkey). Dating to the second half of the 3rd century AD, the sawmill is considered the earliest known machine to combine a crank with a conne ...
, dating to the 3rd century; they are also found in stone
sawmill
A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...
s in
Roman Syria
Roman Syria was an early Roman province annexed to the Roman Republic in 64 BC by Pompey in the Third Mithridatic War following the defeat of King of Armenia Tigranes the Great.
Following the partition of the Herodian Kingdom of Judea into tetr ...
and
Ephesus
Ephesus (; grc-gre, Ἔφεσος, Éphesos; tr, Efes; may ultimately derive from hit, 𒀀𒉺𒊭, Apaša) was a city in ancient Greece on the coast of Ionia, southwest of present-day Selçuk in İzmir Province, Turkey. It was built in t ...
dating to the 6th century.
[: Because of the findings at Ephesus and Gerasa the invention of the crank and connecting rod system has had to be redated from the 13th to the 6th c; now the Hierapolis relief takes it back another three centuries, which confirms that water-powered stone saw mills were indeed in use when Ausonius wrote his Mosella.] The
pediment
Pediments are gables, usually of a triangular shape.
Pediments are placed above the horizontal structure of the lintel, or entablature, if supported by columns. Pediments can contain an overdoor and are usually topped by hood moulds.
A pedimen ...
of the Hierapolis mill shows a
waterwheel
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets ...
fed by a
mill race
A mill race, millrace or millrun, mill lade (Scotland) or mill leat (Southwest England) is the current of water that turns a water wheel, or the channel ( sluice) conducting water to or from a water wheel. Compared with the broad waters of a mi ...
powering via a
gear train
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage.
Gear teeth are designed to ensure the pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission ...
two
frame saw
A frame saw or sash saw is a type of saw which consists of a relatively narrow and flexible blade held under tension within a (generally wooden) rectangular frame (also called a sash or gate). They are used for cutting wood or stone. The blade i ...
s which cut blocks by the way of some kind of connecting rods and cranks. The crank and connecting rod mechanisms of the other two archaeologically-attested sawmills worked without a gear train. Water-powered
marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or Dolomite (mineral), dolomite. Marble is typically not Foliation (geology), foliated (layered), although there are exceptions. In geology, the ...
saws in
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
were mentioned by the late 4th century poet
Ausonius
Decimius Magnus Ausonius (; – c. 395) was a Roman poet and teacher of rhetoric from Burdigala in Aquitaine, modern Bordeaux, France. For a time he was tutor to the future emperor Gratian, who afterwards bestowed the consulship on him. H ...
;
about the same time, these mill types seem also to be indicated by
Gregory of Nyssa
Gregory of Nyssa, also known as Gregory Nyssen ( grc-gre, Γρηγόριος Νύσσης; c. 335 – c. 395), was Bishop of Nyssa in Cappadocia from 372 to 376 and from 378 until his death in 395. He is venerated as a saint in Catholici ...
from
Anatolia
Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...
.
A rotary
grindstone
A grindstone, also known as grinding stone, is a sharpening stone used for grinding or sharpening ferrous tools, used since ancient times. Tools are sharpened by the stone's abrasive qualities that remove material from the tool through friction ...
operated by a crank handle is shown in the
Carolingian
The Carolingian dynasty (; known variously as the Carlovingians, Carolingus, Carolings, Karolinger or Karlings) was a Frankish noble family named after Charlemagne, grandson of mayor Charles Martel and a descendant of the Arnulfing and Pippin ...
manuscript ''
Utrecht Psalter
The Utrecht Psalter (Utrecht, Universiteitsbibliotheek, MS Bibl. Rhenotraiectinae I Nr 32.) is a ninth-century illuminated manuscript, illuminated psalter which is a key masterpiece of Carolingian art; it is probably the most valuable manuscript ...
''; the pen drawing of around 830 goes back to a late antique original. Cranks used to turn wheels are also depicted or described in various works dating from the tenth to thirteenth centuries.
The first depictions of the compound crank in the carpenter's
brace
Brace(s) or bracing may refer to:
Medical
* Orthopaedic brace, a device used to restrict or assist body movement
** Back brace, a device limiting motion of the spine
*** Milwaukee brace, a kind of back brace used in the treatment of spinal cur ...
appear between 1420 and 1430 in northern European artwork.
The rapid adoption of the compound crank can be traced in the works of an unknown German engineer writing on the state of military technology during the Hussite Wars: first, the connecting-rod, applied to cranks, reappeared; second, double-compound cranks also began to be equipped with connecting-rods; and third, the flywheel was employed for these cranks to get them over the 'dead-spot'.
The concept was much improved by the Italian engineer and writer
Roberto Valturio
Roberto Valturio (1405–1475) was an Italian engineer and writer born in Rimini. He was the author of the military treatise ''De Re militari'' (1472).
The work consists of a preface, with a dedication to Sigismondo Pandolfo Malatesta; a list of ...
in 1463, who devised a boat with five sets, where the parallel cranks are all joined to a single power source by one connecting-rod, an idea also taken up by his compatriot Italian painter
Francesco di Giorgio
Francesco di Giorgio Martini (1439–1501) was an Italian architect, engineer, painter, sculptor, and writer. As a painter, he belonged to the Sienese School. He was considered a visionary architectural theorist—in Nikolaus Pevsner's terms ...
.
The crank had become common in Europe by the early 15th century, as seen in the works of the military engineer
Konrad Kyeser
Konrad Kyeser (26 August 1366 – after 1405) was a German military engineer and the author of ''Bellifortis'' (c. 1405), a book on military technology that was popular throughout the 15th century. Originally conceived for King Wenceslaus, ...
(1366–after 1405).
[.] Devices depicted in Kyeser's ''
Bellifortis
''Bellifortis'' ("Strong in War", "War Fortifications") is the first fully illustrated manual of military technology written by Konrad Kyeser and dating from the start of the 15th century. It summarises material from classical writers on milita ...
'' include cranked windlasses for spanning siege crossbows, cranked chain of buckets for water-lifting and cranks fitted to a wheel of bells.
Kyeser also equipped the
Archimedes' screw
The Archimedes screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest hydraulic machines. Using Archimedes screws as water pumps (Archimedes screw pump (ASP) or screw pump) dates back ...
s for water-raising with a crank handle, an innovation which subsequently replaced the ancient practice of working the pipe by treading.
Pisanello
Pisanello (c. 1380/1395c. 1450/1455), born Antonio di Puccio Pisano or Antonio di Puccio da Cereto, also erroneously called Vittore Pisano by Giorgio Vasari, was one of the most distinguished painters of the early Italian Renaissance and Quattroc ...
painted a piston-pump driven by a water-wheel and operated by two simple cranks and two connecting-rods.
The 15th also century saw the introduction of cranked rack-and-pinion devices, called cranequins, which were fitted to the
crossbow
A crossbow is a ranged weapon using an elastic launching device consisting of a bow-like assembly called a ''prod'', mounted horizontally on a main frame called a ''tiller'', which is hand-held in a similar fashion to the stock of a long fi ...
's stock as a means of exerting even more force while spanning the missile weapon. In the textile industry, cranked
reel
A reel is an object around which a length of another material (usually long and flexible) is wound for storage (usually hose are wound around a reel). Generally a reel has a cylindrical core (known as a '' spool'') with flanges around the en ...
s for winding skeins of yarn were introduced.
The Italian physician
Guido da Vigevano
Guido da Vigevano or Guido da Vigevano da Pavia (born c. 1280; died c. 1349) was an Italian physician and inventor. He is notable for his sketchbook ''Texaurus regis Francie'', a catalog of military equipment, and his ''Anothomia Philippi Septimi' ...
(c. 1280−1349), planning for a new crusade, made illustrations for a
paddle boat and war carriages that were propelled by manually turned compound cranks and gear wheels, identified as an early crankshaft prototype by
Lynn Townsend White
Lynn Townsend White Jr. (April 29, 1907 – March 30, 1987) was an American historian. He was a professor of Middle Ages, medieval history at Princeton University, Princeton from 1933 to 1937, and at Stanford University, Stanford from 1937 to 194 ...
. The ''
Luttrell Psalter
The Luttrell Psalter (British Library, Add MS 42130) is an illuminated manuscript, illuminated psalter commissioned by Sir Geoffrey Luttrell (1276–1345), lord of the manor of Irnham in Lincolnshire, written and illustrated on parchment ''circa'' ...
'', dating to around 1340, describes a grindstone which was rotated by two cranks, one at each end of its axle; the geared hand-mill, operated either with one or two cranks, appeared later in the 15th century.
![Fotothek df tg 0006690 Mechanik ^ Wasserförderung ^ Pumpe](https://upload.wikimedia.org/wikipedia/commons/5/55/Fotothek_df_tg_0006690_Mechanik_%5E_Wasserf%C3%B6rderung_%5E_Pumpe.jpg)
Around 1480, the early medieval rotary grindstone was improved with a treadle and crank mechanism. Cranks mounted on push-carts first appear in a German engraving of 1589. Crankshafts were also described by
Leonardo da Vinci
Leonardo di ser Piero da Vinci (15 April 14522 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, Drawing, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially res ...
(1452–1519)
[ and a Dutch farmer and windmill owner by the name ]Cornelis Corneliszoon van Uitgeest
Cornelis Corneliszoon van Uitgeest, or Krelis Lootjes (c. 1550 - c. 1600) was a Dutch windmill owner from Uitgeest who invented the wind-powered sawmill, which made the conversion of log timber into planks 30 times faster than before.[sawmill
A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...]
used a crankshaft to convert a windmill's circular motion into a back-and-forward motion powering the saw. Corneliszoon was granted a patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...
for his crankshaft in 1597.
From the 16th century onwards, evidence of cranks and connecting rods integrated into machine design becomes abundant in the technological treatises of the period: Agostino Ramelli
Agostino Ramelli (1531–ca. 1610) was an Italian engineer best known for writing and illustrating the book of engineering designs ''Le diverse et artificiose machine del Capitano Agostino Ramelli'', which contains, among others, his design ...
's ''The Diverse and Artifactitious Machines'' of 1588 depicts eighteen examples, a number that rises in the ''Theatrum Machinarum Novum'' by Georg Andreas Böckler
Georg Andreas Böckler (c. 1617 – 21 February 1687) was a German architect and engineer who wrote ''Architectura Curiosa Nova'' (1664) and ''Theatrum Machinarum Novum'' (1661).
Biography
Born in Cronheim, he was an architect in the city of N ...
to 45 different machines. Cranks were formerly common on some machines in the early 20th century; for example almost all phonograph
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
s before the 1930s were powered by clockwork
Clockwork refers to the inner workings of either mechanical devices called clocks and watches (where it is also called the movement) or other mechanisms that work similarly, using a series of gears driven by a spring or weight.
A clockwork mec ...
motors wound with cranks. Reciprocating piston engines use cranks to convert the linear piston motion into rotational motion. Internal combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...
s of early 20th century automobile
A car or automobile is a motor vehicle with Wheel, wheels. Most definitions of ''cars'' say that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, pe ...
s were usually started with hand cranks, before electric starters came into general use.
Western Asia
The non-manual crank appears in several of the hydraulic devices described by the Banū Mūsā
The Banū Mūsā brothers ("Sons of Moses"), namely Abū Jaʿfar, Muḥammad ibn Mūsā ibn Shākir (before 803 – February 873); Abū al‐Qāsim, Aḥmad ibn Mūsā ibn Shākir (d. 9th century); and Al-Ḥasan ibn Mūsā ibn Shākir (d. 9th ce ...
brothers in their 9th-century ''Book of Ingenious Devices
The ''Book of Ingenious Devices'' (Arabic: كتاب الحيل ''Kitab al-Hiyal'', Persian: كتاب ترفندها ''Ketab tarfandha'', literally: "The Book of Tricks") is a large illustrated work on mechanical devices, including automata, publi ...
''. These automatically operated cranks appear in several devices, two of which contain an action which approximates to that of a crankshaft, anticipating Ismail al-Jazari
Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī (1136–1206, ar, بديع الزمان أَبُ اَلْعِزِ إبْنُ إسْماعِيلِ إبْنُ الرِّزاز الجزري, ) was a polymath: a scholar, ...
's invention by several centuries and its first appearance in Europe by over five centuries. The automatic crank described by the Banū Mūsā would not have allowed a full rotation, however, but only a small modification was required to convert it to a crankshaft.
Arab engineer Ismail al-Jazari
Badīʿ az-Zaman Abu l-ʿIzz ibn Ismāʿīl ibn ar-Razāz al-Jazarī (1136–1206, ar, بديع الزمان أَبُ اَلْعِزِ إبْنُ إسْماعِيلِ إبْنُ الرِّزاز الجزري, ) was a polymath: a scholar, ...
(1136–1206), in the Artuqid Sultanate, described a crank and connecting rod system in a rotating machine in two of his water-raising machines.Ahmad Y Hassan
Ahmad Yousef Al-Hassan ( ar, links=no, أحمد يوسف الحسن) (June 25, 1925 – April 28, 2012) was a Palestinian/Syrian/Canadian historian of Arabic and Islamic science and technology, educated in Jerusalem, Cairo, and London with a PhD i ...
The Crank-Connecting Rod System in a Continuously Rotating Machine
The author Sally Ganchy identified a crankshaft in his twin-cylinder pump
A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic energy. Pumps can be classified into three major groups according to the method they u ...
mechanism, including both the crank and shaft mechanisms.Donald Hill
Donald Routledge Hill (6 August 1922 – 30 May 1994)D. A. King, “In Memoriam: Donald Routledge Hill (1922-1994)”, ''Arabic Sciences and Philosophy,'' Volume 5 / Issue 02 / September 1995, pp 297-302 was a British engineer and historian of sc ...
(2012)
''The Book of Knowledge of Ingenious Mechanical Devices'', page 273
Springer Science + Business Media
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing.
Originally founded in 1842 in ...
See also
* Bicycle crankset
*Brace (tool)
A brace is a hand tool used with a bit (drill bit or auger) to drill holes, usually in wood. Pressure is applied to the top and the tool is rotated with a U-shaped grip. Bits used come in a variety of types but the more commonly used Ridgeway ...
*Cam
Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the bind ...
*Cam engine
A cam engine is a reciprocating engine where, instead of the conventional crankshaft, the pistons deliver their force to a cam that is then caused to rotate. The output work of the engine is driven by this cam.
Cam engines are deeply rooted in his ...
*Camshaft
A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems ...
*Crank (mechanism)
A crank is an arm attached at a right angle to a rotating shaft by which circular motion is imparted to or received from the shaft. When combined with a connecting rod, it can be used to convert circular motion into reciprocating motion, or vice ...
*Crankcase
In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block.
Two-stroke engines typically use a crankcase-compression design, resulting in the fuel/a ...
* Crankshaft torsional vibration
*Piston motion equations The reciprocating motion of a non-offset piston connected to a rotating crank through a connecting rod (as would be found in internal combustion engines) can be expressed by equations of motion. This article shows how these equations of motion ca ...
* Tunnel crankshaft
*Scotch yoke
The Scotch Yoke (also known as slotted link mechanism) is a reciprocating motion mechanism, converting the linear motion of a slider into rotational motion, or vice versa. The piston or other reciprocating part is directly coupled to a sliding yo ...
*Swashplate
A swashplate, also known as slant disk, was invented by Anthony Michell in 1917. It is a mechanical engineering device used to translate the motion of a rotating shaft into reciprocating motion, or vice versa. The working principle is similar to c ...
References
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External links
*Interactive crank animation https://www.desmos.com/calculator/8l2kvyivqo
*D & T Mechanisms - Interactive Tools for Teachers (applets) https://web.archive.org/web/20140714155346/http://www.content.networcs.net/tft/mechanisms.htm
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Engine components
Engine technology
Linkages (mechanical)
Piston engines