Swashplate engine
Encyclopedia
A swashplate engine, also called a barrel engine, is one type of axial engine. Swashplate engines are a type of reciprocating engine
that replaces the common crankshaft
with a circular swashplate
which rotates.
The key advantage of the swashplate design is that the cylinders are arranged in parallel around the edge of the plate, and possibly on either side of it as well, and are aligned with the output shaft rather than at 90 degrees as in crankshaft engines. As a result it is a very compact, cylindrical engine. The arrangement also allows the compression ratio
of the engine to be changed while running by adjusting the distance of the plate from the cylinders. In a swashplate engine the piston rods stay parallel with the shaft, and piston side-forces that cause excessive wear can be eliminated almost completely. The small-end bearing of a traditional connecting rod, one of the most problematic bearing in a traditional engine, is eliminated. An alternate design, the Rand cam engine
, replaces the plate with a sine-shaped cam
.
A wobble-plate is similar to a swashplate, in that the pistons press down on the plate in sequence, forcing it to nutate
around its center. This motion can be simulated by placing a Compact Disc
on a ball bearing
at its centre and pressing down at progressive places around its circumference. The difference is that while a wobble plate nutates, a swash-plate rotates.
In 1911 the Macomber Rotary Engine Company of Los Angeles marketed one of the first axial internal-combustion engines, manufactured by the Avis Engine Company of Allston, Massachusetts. A four-stroke, air-cooled unit, it had seven cylinders and a variable compression ratio, altered by changing the wobble-plate angle and hence the length of piston stroke. It was called a "rotary engine" because the entire engine rotated apart from the end casings.
Ignition was supplied by a Bosch
magneto
directly driven from the cam gears. The high voltage
current was then taken to a fixed electrode on the front bearing case, from which the sparks would jump to the spark plugs in the cylinder heads as they passed within 1/16 inch from it. According to Macomber's literature, it was "Guaranteed not to overheat".
The engine was claimed to be able to run at 150 to 1,500 rpm. At the normal speed of 1,000 rpm, it reportedly developed 50 hp. It weighed 230 pounds (104.3 kg) and it was 28 inches (711.2 mm) long by 19 inches (482.6 mm) in diameter.
Pioneer aviator Charles Francis Walsh
flew an aircraft powered by a Macomber engine in May 1911, the "Walsh Silver Dart".
, London
. In 1914 the company moved to London to become the Statax Engine Company and planned on introducing a series of rotary engine
s; a 3-cylinder of 10 hp, a 5-cylinder of 40 hp, a 7-cylinder of 80 hp, and a 10-cylinder of 100 hp.
It appears only the 40 hp design was ever produced, which was installed in a Caudron G.II for the British 1914 Aerial Derby but was withdrawn before the flight. Hansen introduced an all-aluminum version of this design in 1922, but it is not clear if they produced it in any quantity. Much improved versions were introduced by Statax's German division in 1929, producing 42 hp in a new sleeve valve
version known as the 29B. Greenwood and Raymond of San Francisco acquired the patent rights for the US, Canada, and Japan, and planned a 5-cylinder of 100 hp and a 9-cylinder of 350 hp.
obtained patents for his swashplate engine design. Its unique feature was the means of transferring the load from the pistons to the swashplate, achieved using tilting slipper pads sliding on a film of oil. Another innovation by Michell was his mathematical analysis of the mechanical design, including the mass and motion of the components, so that his engines were in perfect dynamic balance at all speeds.
In 1920 Michell established the Crankless Engines Company in Fitzroy (Australia), and produced working prototypes of pumps, compressors, car engines and aero engines, all based on the same basic design.
The legendary Phil Irving worked for the Crankless Engine Company before his time at HRD.
A number of companies obtained a manufacturing licence for Michell’s design. The most successful of these was the British company Waller and Son, who produced gas boosters.
The largest Michell crankless engine was the XB-4070, a diesel aircraft engine built for the US Navy. Consisting of 18 pistons, it was rated at 2000 horsepower and weighed 2150 pounds.
s. The A-4 had much smaller frontal area than water-cooled engines of comparable power output, and thereby offered better streamlining possibilities. It was rated at 425 horsepower (317 kW), and weighed only 749 pounds (340 kg), thus giving a power/weight ratio of better than 1:2, a considerable design achievement at the time.
aviator who was knight
ed at the age of 18 by King Alfonso XIII
of Spain for designing, building, and flying Spain's first airplane. He developed a barrel engine for aircraft use which was later produced by the Indian Motorcycle Company
as the Alfaro. It was a perfect example of the "put in everything" design, as it included a sleeve valve
system based on a rotating cylinder head, a design that never entered production on any engine. It was later developed further for use in the Doman helicopter
by Stephen duPont, son of the president of the Indian Motorcycle Company, who had been one of Alfaro's students at MIT.
for the Bristol Tramways and Carriage Company; it was a 7-litre, 9-cylinder, wobble-plate type engine. It was originally conceived as a power unit for buses, possibly because its compact format would allow it to be installed beneath the vehicle's floor. The engine had a single rotary valve to control induction and exhaust. Several variants were used in Bristol buses during the late 1930s, the engine going through several versions from RR1 to RR4, which had a power output of 145 hp at 2900 rpm. Development was halted in 1936 following a change of management at the Bristol company.
wobble-plate engine of 1947. This 6-cylinder engine was designed by John Wooler, better known as a motorcycle engine designer, for aircraft use. It was similar to the Bristol axial engine but had two wobble-plates, driven by 12 opposed pistons in 6 cylinders. The engine is often incorrectly referred to as a swashplate engine. A single example is preserved in the Aeroplane Gallery of The Science Museum
, London.
for marine usage.
in 1916. They sold the rights to Karl Herrmann, Studebaker's head of engineering, who developed the concept over many years, eventually taking out US patent 2237989 in 1941. It has 6 double-ended pistons working in 6 cylinders, and its 12 combustion chambers are fired every revolution of the drive shaft. The pistons drive a sine-shaped cam, as opposed to a swashplate or wobble-plate, hence its name.
In 1961, at the age of 80, Herrmann sold the rights to one of his employees, Edward Palmer, who set up the Dyna-Cam Engine Corp. along with son Dennis. Edward's son Dennis and daughter Pat then helped get the engine installed in a Piper Arrow. The engine was flown for about 700 hours in the Piper Arrow from 1987 through 1991. Their longest engine ran for nearly 4000 hours before overhaul. Dyna-Cam opened an R & D facility in around 1993 and won many various awards from NASA, US Navy, the US Marine Corps, California Energy Commission, Air Quality Management District, and Los Angeles Regional Technology Alliance for different variations of the same Dyna-Cam Engine. About 40 prototype engines were built by the Herrmann Group and another 25 built by the Dyna-Cam Group since they acquired the engine and opened their shop. A new patent was granted to Dennis Palmer and Edward Palmer first in 1985 and then several more around 2000 to Dennis Palmer. In 2003 the assets of the Dyna-Cam Engine Corp were acquired by first Aero-Marine Corp. who changed their name to Axial Vector Engine Corporation. Axial Vector then totally re-designed the cam engine. Axial Vector's new engine, like many of the others on this list, suffers from the "put in everything" problem, including piezoelectric valves and ignition, ceramic cylinder liners with no piston rings, and a variety of other advanced features. It has almost no similarity to the original Herrmann and Dyna-Cam Engine since the Dyna-Cam Engine used conventional valves, piston rings, accessories, had no unproven ceramic materials and actually flew in a Piper Arrow and also powered a 20 feet (6.1 m) Eliminator Ski Boat for over four years.
, in the DN-01
motorcycle was announced in 2005, and began selling in 2008. It is the first production, road-going vehicle with hydrostatic drive.
Reciprocating engine
A reciprocating engine, also often known as a piston engine, is a heat engine that uses one or more reciprocating pistons to convert pressure into a rotating motion. This article describes the common features of all types...
that replaces the common crankshaft
Crankshaft
The crankshaft, sometimes casually abbreviated to crank, is the part of an engine which translates reciprocating linear piston motion into rotation...
with a circular swashplate
Swashplate
A swashplate is a device used in mechanical engineering to translate the motion of a rotating shaft into reciprocating motion, or to translate a reciprocating motion into a rotating one to replace the crankshaft in engine designs.- Construction :...
which rotates.
The key advantage of the swashplate design is that the cylinders are arranged in parallel around the edge of the plate, and possibly on either side of it as well, and are aligned with the output shaft rather than at 90 degrees as in crankshaft engines. As a result it is a very compact, cylindrical engine. The arrangement also allows the compression ratio
Compression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...
of the engine to be changed while running by adjusting the distance of the plate from the cylinders. In a swashplate engine the piston rods stay parallel with the shaft, and piston side-forces that cause excessive wear can be eliminated almost completely. The small-end bearing of a traditional connecting rod, one of the most problematic bearing in a traditional engine, is eliminated. An alternate design, the Rand cam engine
Rand cam engine
The RadMax engine, also known as Ram-cam or Rand-cam engine is a pistonless rotary engine being developed by Reg/Regi Technologies Inc.- Design :...
, replaces the plate with a sine-shaped cam
Cam
A cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice-versa. It is often a part of a rotating wheel or shaft that strikes a lever at one or more points on its circular path...
.
A wobble-plate is similar to a swashplate, in that the pistons press down on the plate in sequence, forcing it to nutate
Nutation
Nutation is a rocking, swaying, or nodding motion in the axis of rotation of a largely axially symmetric object, such as a gyroscope, planet, or bullet in flight, or as an intended behavior of a mechanism...
around its center. This motion can be simulated by placing a Compact Disc
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...
on a ball bearing
Ball bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit...
at its centre and pressing down at progressive places around its circumference. The difference is that while a wobble plate nutates, a swash-plate rotates.
Macomber
Ignition was supplied by a Bosch
Robert Bosch GmbH
Robert Bosch GmbH is a multinational engineering and electronics company headquartered in Gerlingen, near Stuttgart, Germany. It is the world's largest supplier of automotive components...
magneto
Magneto
A magneto is a type of electrical generator.Magneto may also refer to:* Magneto , permanent magnetic alternating current rotary generator* ignition magneto, magnetos on internal combustion engines...
directly driven from the cam gears. The high voltage
High voltage
The term high voltage characterizes electrical circuits in which the voltage used is the cause of particular safety concerns and insulation requirements...
current was then taken to a fixed electrode on the front bearing case, from which the sparks would jump to the spark plugs in the cylinder heads as they passed within 1/16 inch from it. According to Macomber's literature, it was "Guaranteed not to overheat".
The engine was claimed to be able to run at 150 to 1,500 rpm. At the normal speed of 1,000 rpm, it reportedly developed 50 hp. It weighed 230 pounds (104.3 kg) and it was 28 inches (711.2 mm) long by 19 inches (482.6 mm) in diameter.
Pioneer aviator Charles Francis Walsh
Charles Francis Walsh
Charles Francis Walsh was a pioneer aviator who died in a crash in Trenton, New Jersey.-Biography:...
flew an aircraft powered by a Macomber engine in May 1911, the "Walsh Silver Dart".
Statax
In 1913 Statax-Motor of Zurich, Switzerland introduced a swashplate engine design. Only a single prototype was produced, which is currently held in the Science MuseumScience museum
A science museum or a science centre is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in museology have broadened the range of...
, London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
. In 1914 the company moved to London to become the Statax Engine Company and planned on introducing a series of rotary engine
Rotary engine
The rotary engine was an early type of internal-combustion engine, usually designed with an odd number of cylinders per row in a radial configuration, in which the crankshaft remained stationary and the entire cylinder block rotated around it...
s; a 3-cylinder of 10 hp, a 5-cylinder of 40 hp, a 7-cylinder of 80 hp, and a 10-cylinder of 100 hp.
It appears only the 40 hp design was ever produced, which was installed in a Caudron G.II for the British 1914 Aerial Derby but was withdrawn before the flight. Hansen introduced an all-aluminum version of this design in 1922, but it is not clear if they produced it in any quantity. Much improved versions were introduced by Statax's German division in 1929, producing 42 hp in a new sleeve valve
Sleeve valve
The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve-valve engines saw use in a number of pre-World War II luxury cars and in USA in the Willys-Knight car and light truck...
version known as the 29B. Greenwood and Raymond of San Francisco acquired the patent rights for the US, Canada, and Japan, and planned a 5-cylinder of 100 hp and a 9-cylinder of 350 hp.
Michell
In 1917 Anthony MichellAnthony Michell
Anthony George Maldon Michell FRS was an Australian mechanical engineer of the early 20th century.-Early life:...
obtained patents for his swashplate engine design. Its unique feature was the means of transferring the load from the pistons to the swashplate, achieved using tilting slipper pads sliding on a film of oil. Another innovation by Michell was his mathematical analysis of the mechanical design, including the mass and motion of the components, so that his engines were in perfect dynamic balance at all speeds.
In 1920 Michell established the Crankless Engines Company in Fitzroy (Australia), and produced working prototypes of pumps, compressors, car engines and aero engines, all based on the same basic design.
The legendary Phil Irving worked for the Crankless Engine Company before his time at HRD.
A number of companies obtained a manufacturing licence for Michell’s design. The most successful of these was the British company Waller and Son, who produced gas boosters.
The largest Michell crankless engine was the XB-4070, a diesel aircraft engine built for the US Navy. Consisting of 18 pistons, it was rated at 2000 horsepower and weighed 2150 pounds.
J.O. Almen
Experimental barrel engines for aircraft use were built and tested by Mr J.O. Almen of Seattle in the early 1920s, and by the mid-1920s the water-cooled Almen A-4 (18 cylinders, two groups of nine each horizontally opposed) had passed its United States Air Corps acceptance tests. It however never entered production, reportedly due to limited funds and the Air Corps' growing emphasis on air-cooled radial engineRadial engine
The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...
s. The A-4 had much smaller frontal area than water-cooled engines of comparable power output, and thereby offered better streamlining possibilities. It was rated at 425 horsepower (317 kW), and weighed only 749 pounds (340 kg), thus giving a power/weight ratio of better than 1:2, a considerable design achievement at the time.
Heraclio Alfaro
Heraclio Alfaro was a SpanishSpain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
aviator who was knight
Knight
A knight was a member of a class of lower nobility in the High Middle Ages.By the Late Middle Ages, the rank had become associated with the ideals of chivalry, a code of conduct for the perfect courtly Christian warrior....
ed at the age of 18 by King Alfonso XIII
Alfonso XIII of Spain
Alfonso XIII was King of Spain from 1886 until 1931. His mother, Maria Christina of Austria, was appointed regent during his minority...
of Spain for designing, building, and flying Spain's first airplane. He developed a barrel engine for aircraft use which was later produced by the Indian Motorcycle Company
Indian (motorcycle)
Indian is an American brand of motorcycles. Indian motorcycles were manufactured from 1901 to 1953 by a company in Springfield, Massachusetts, USA, initially known as the Hendee Manufacturing Company but which was renamed the Indian Manufacturing Company in 1928. The Indian factory team took the...
as the Alfaro. It was a perfect example of the "put in everything" design, as it included a sleeve valve
Sleeve valve
The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve-valve engines saw use in a number of pre-World War II luxury cars and in USA in the Willys-Knight car and light truck...
system based on a rotating cylinder head, a design that never entered production on any engine. It was later developed further for use in the Doman helicopter
Doman LZ-5
-See also:...
by Stephen duPont, son of the president of the Indian Motorcycle Company, who had been one of Alfaro's students at MIT.
Bristol
The Bristol Axial Engine of the mid 1930s was designed by Charles Benjamin RedrupCharles Benjamin Redrup
Charles Benjamin Redrup was a British aeronautical engineer and inventor, who designed several innovative axial engines.-Early life:Redrup was born in Newport, Wales in 1878, his father moving to Barry, Vale of Glamorgan shortly afterwards...
for the Bristol Tramways and Carriage Company; it was a 7-litre, 9-cylinder, wobble-plate type engine. It was originally conceived as a power unit for buses, possibly because its compact format would allow it to be installed beneath the vehicle's floor. The engine had a single rotary valve to control induction and exhaust. Several variants were used in Bristol buses during the late 1930s, the engine going through several versions from RR1 to RR4, which had a power output of 145 hp at 2900 rpm. Development was halted in 1936 following a change of management at the Bristol company.
Wooler
Perhaps the most refined of the designs was the British WoolerWooler (motorcycles)
Wooler was a British manufacturer of motorcycles and other vehicles, founded by engineer John Wooler in 1911 based in Alperton, Middlesex. The company became known for its unconventional designs which included several fore-and-aft twins, a vertical camshaft single cylinder machine, a...
wobble-plate engine of 1947. This 6-cylinder engine was designed by John Wooler, better known as a motorcycle engine designer, for aircraft use. It was similar to the Bristol axial engine but had two wobble-plates, driven by 12 opposed pistons in 6 cylinders. The engine is often incorrectly referred to as a swashplate engine. A single example is preserved in the Aeroplane Gallery of The Science Museum
Science museum
A science museum or a science centre is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in museology have broadened the range of...
, London.
H.L.F Trebert
Some small barrel engines were produced by the H.L.F. Trebert Engine Works of Rochester, New YorkRochester, New York
Rochester is a city in Monroe County, New York, south of Lake Ontario in the United States. Known as The World's Image Centre, it was also once known as The Flour City, and more recently as The Flower City...
for marine usage.
Dyna-Cam
The Dyna-Cam engine originally came from a design by the Blazer brothers, who worked for StudebakerStudebaker
Studebaker Corporation was a United States wagon and automobile manufacturer based in South Bend, Indiana. Founded in 1852 and incorporated in 1868 under the name of the Studebaker Brothers Manufacturing Company, the company was originally a producer of wagons for farmers, miners, and the...
in 1916. They sold the rights to Karl Herrmann, Studebaker's head of engineering, who developed the concept over many years, eventually taking out US patent 2237989 in 1941. It has 6 double-ended pistons working in 6 cylinders, and its 12 combustion chambers are fired every revolution of the drive shaft. The pistons drive a sine-shaped cam, as opposed to a swashplate or wobble-plate, hence its name.
In 1961, at the age of 80, Herrmann sold the rights to one of his employees, Edward Palmer, who set up the Dyna-Cam Engine Corp. along with son Dennis. Edward's son Dennis and daughter Pat then helped get the engine installed in a Piper Arrow. The engine was flown for about 700 hours in the Piper Arrow from 1987 through 1991. Their longest engine ran for nearly 4000 hours before overhaul. Dyna-Cam opened an R & D facility in around 1993 and won many various awards from NASA, US Navy, the US Marine Corps, California Energy Commission, Air Quality Management District, and Los Angeles Regional Technology Alliance for different variations of the same Dyna-Cam Engine. About 40 prototype engines were built by the Herrmann Group and another 25 built by the Dyna-Cam Group since they acquired the engine and opened their shop. A new patent was granted to Dennis Palmer and Edward Palmer first in 1985 and then several more around 2000 to Dennis Palmer. In 2003 the assets of the Dyna-Cam Engine Corp were acquired by first Aero-Marine Corp. who changed their name to Axial Vector Engine Corporation. Axial Vector then totally re-designed the cam engine. Axial Vector's new engine, like many of the others on this list, suffers from the "put in everything" problem, including piezoelectric valves and ignition, ceramic cylinder liners with no piston rings, and a variety of other advanced features. It has almost no similarity to the original Herrmann and Dyna-Cam Engine since the Dyna-Cam Engine used conventional valves, piston rings, accessories, had no unproven ceramic materials and actually flew in a Piper Arrow and also powered a 20 feet (6.1 m) Eliminator Ski Boat for over four years.
Fairdiesel
UK company FairDiesel Limited is designing two-stroke diesel opposed piston barrel engines which use non-sinusoidal cams, for industrial applications and aviation use. Their designs range from a 2-cylinder, 80 mm bore engine to a 32-cylinder, 160 mm bore one.Honda
After introducing a hydrostatic drive in 2001 for their FourTrax Rubicon ATVAll-terrain vehicle
An all-terrain vehicle , also known as a quad, quad bike, three wheeler, or four wheeler, is defined by the American National Standards Institute as a vehicle that travels on low pressure tires, with a seat that is straddled by the operator, along with handlebars for steering control...
, in the DN-01
Honda DN-01
-External links:* official page* in Popular Science...
motorcycle was announced in 2005, and began selling in 2008. It is the first production, road-going vehicle with hydrostatic drive.
Applications
- The most well-known application is in torpedoTorpedoThe modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
es, where the cylindrical shape is desirable. The modern Mark 48 torpedoMark 48 torpedoThe Mark 48 and its improved ADCAP variant are heavyweight submarine-launched torpedoes. They were designed to sink fast, deep-diving nuclear-powered submarines and high-performance surface ships.-History:...
is powered by a 500 hp swashplate engine geared to a pump-jetPump-jetA pump-jet, hydrojet, or water jet, is a marine system that creates a jet of water for propulsion. The mechanical arrangement may be a ducted propeller with nozzle, or a centrifugal pump and nozzle...
propulsor. It is fueled by Otto fuel IIOtto fuel IIOtto fuel II is a monopropellant used to drive torpedoes and other weapon systems. It is not related to the Otto cycle.-Properties:This distinct-smelling, reddish-orange, oily liquid is a mixture of three synthetic substances: propylene glycol dinitrate , 2-nitrodiphenylamine, and dibutyl...
, a monopropellantMonopropellantMonopropellants are propellants composed of chemicals or mixtures of chemicals which can be stored in a single container with some degree of safety. While stable under defined storage conditions, they react very rapidly under certain other conditions to produce a large volume of energetic gases...
that requires no oxygen supply and can propel the torpedo at up to 65 knots (127.4 km/h) (74.56 mph).
- Other applications include pneumatic and hydraulic motors, hydrostatic transmissions such as HondaHondais a Japanese public multinational corporation primarily known as a manufacturer of automobiles and motorcycles.Honda has been the world's largest motorcycle manufacturer since 1959, as well as the world's largest manufacturer of internal combustion engines measured by volume, producing more than...
's Hondamatic CVTContinuously variable transmissionA continuously variable transmission is a transmission that can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios...
, and air conditioner pumps. Also, some Stirling engineStirling engineA Stirling engine is a heat engine operating by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work....
s use a swashplate arrangement, e.g. Stirling Thermal Motors' STM 4-120 engine.