A Roots blower

The Roots type supercharger or Roots blower is a positive displacement type device which operates by pulling air through a pair of meshing lobes not unlike a set of stretched gears. Air is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The supercharger is typically driven directly from the engine's crankshaft via a belt or, in a two-stroke Diesel engine, by spur gears. Image File history File links Rotary_piston_pump. ... Image File history File links Rotary_piston_pump. ... A supercharger (also known as a blower) is an air compressor used to force more air (and hence more oxygen) into the combustion chamber(s) of an internal combustion engine than can be achieved at ambient atmospheric pressure. ... In common usage positive is sometimes used in affirmation, as a synonym for yes or to express certainty. Look up Positive on Wiktionary, the free dictionary In mathematics, a number is called positive if it is bigger than zero. ... One complete cycle of a four cylinder, four stroke engine. ... Layers of Atmosphere (NOAA) Air redirects here. ... Spur gears found on a piece of farm equipment. ... An engine is something that produces an effect from a given input. ... Crankshaft (red), pistons (gray) in their cylinders (blue), and flywheel (black) Continental engine marine crankshafts, 1942 Components of a typical, four stroke cycle, DOHC piston engine. ... v-belt flat belt Belts are used to mechanically link two or more rotating items. ... The two-stroke cycle of an internal combustion engine differs from the more common four-stroke cycle by completing the same four processes (intake, compression, power, exhaust) in only two strokes of the piston rather than four. ... This article or section does not cite any references or sources. ... Spur gears found on a piece of farm equipment. ...

It is named for the brothers Philander and Francis Roots, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industrial applications. In 1900, Gottlieb Daimler included a Roots-style supercharger in a patented engine design, making the Roots-type supercharger the oldest of the various designs now available. A patent is a set of exclusive rights granted by a state to a patentee for a fixed period of time in exchange for a disclosure of an invention. ... 1860 is the leap year starting on Sunday. ... Manual pump used to obtain water A pump is a mechanical device used to move liquids or gases. ... Blast furnace in Sestao, Spain. ... Year 1900 (MCM) was an exceptional common year starting on Monday (link will display the full calendar) of the Gregorian calendar, but a leap year starting on Saturday of the Julian calendar. ... Gottlieb Daimler Gottlieb Wilhelm Daimler (March 17, 1834 - March 6, 1900) was an engineer, industrial designer and industrialist, born in Schorndorf (Kingdom of Württemberg) what is now Germany. ...

Applications

An Eaton M62 Roots-type supercharger is visible at the front of this Ecotec LSJ engine in a 2006 Saturn ION Red Line

Out of the three basic supercharger types the Roots has historically been considered the least efficient. However, recent engineering developments by Eaton Corporation has resulted in a new Roots-type supercharger which yields a pump that is more efficient than all previous models. In addition, the Roots-type supercharger is simple and widely used and thus is invariably the most cost efficient. It is also more effective than alternative superchargers at developing compression at low engine rpms, making it a popular choice for passenger automobile applications. Peak torque can be achieved by about 2000 rpm. Image File history File links Download high resolution version (2272x1704, 434 KB) Summary 2006 Saturn ION Red Line Ecotec Family II LSJ engine Licensing File links The following pages link to this file: Roots type supercharger GM Family II engine ... Image File history File links Download high resolution version (2272x1704, 434 KB) Summary 2006 Saturn ION Red Line Ecotec Family II LSJ engine Licensing File links The following pages link to this file: Roots type supercharger GM Family II engine ... A supercharger (also known as a blower) is an air compressor used to force more air (and hence more oxygen) into the combustion chamber(s) of an internal combustion engine than can be achieved at ambient atmospheric pressure. ... The Family II is a straight-4 piston engine that was originally developed by Opel in late 1970s for use in the Opel Ascona B and Opel Kadett D. Over time, the engine block has evolved to include many modern features such as DOHC and fuel injection. ... The Saturn ION is a compact car sold by General Motors Saturn marque. ... History is often used as a generic term for information about the past, such as in geologic history of the Earth. When used as the name of a field of study, history refers to the study and interpretation of the record of human societies. ... Efficiency is the capability of acting or producing effectively with a minimum of waste, expense, or unnecessary effort. ... Engineering is the design, analysis, and/or construction of works for practical purposes. ... Eaton Corporation (NYSE: ETN), a Fortune 500 company based in Cleveland, Ohio, USA, is a global diversified industrial manufacturer with 2002 sales of $7. ... In economics, business, and accounting, a cost is the value of inputs that have been used up to produce something, and hence are not available for use anymore. ... Bold text Wiktionary has related dictionary definitions, such as: compressor, compression inthe wkjhrlfidhb;g/df == Compressor may refer to: Gas compressor, a mechanical device that compresses a gas e. ... Revolutions per minute (abbreviated rpm, RPM, r/min, or min-1) is a unit of frequency, commonly used to measure rotational speed, in particular in the case of rotation around a fixed axis. ... A passenger is a term broadly used to describe any person who travels in a vehicle, but bears little or no responsibility for the tasks required for that vehicle to arrive at its destination. ... Karl Benzs Velo (vélo means bicycle in French) model (1894) - entered into the first automobile race 2005 MINI Cooper S. An automobile (also motor car or simply car) is a wheeled passenger vehicle that carries its own motor. ... Torque applied via an adjustable end wrench Relationship between force, torque, and momentum vectors in a rotating system In physics, torque (or often called a moment) can informally be thought of as rotational force or angular force which causes a change in rotational motion. ...

All supercharger types benefit from the use of an intercooler to remove heat produced during compression. With a Roots-type supercharger, a thin heat exchanger is adapted to fit in-between the blower and the engine. Water is circulated through it to a second unit placed near the front of the vehicle where a fan and the ambient air-stream can dissipate the collected heat. It has been suggested that Front mounted intercooler, Top mounted intercooler and Charge cooler be merged into this article or section. ... In physics, heat, symbolized by Q, is defined as transfer of thermal energy [1] Generally, heat is a form of energy transfer associated with the different motions of atoms, molecules and other particles that comprise matter when it is hot and when it is cold. ... A heat exchanger is a device built for efficient heat transfer from one fluid to another, whether the fluids are separated by a solid wall so that they never mix, or the fluids are directly contacted. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Fan may refer to the following: Fan (aficionado) (the bracketed word being the Spanish translation), someone who has an intense liking of a sporting. ...

The Roots design is commonly used on two-stroke diesel engines, which require some form of forced induction as there is no intake stroke. In this application, the blower does not often provide significant compression and these engines are considered naturally aspirated; turbochargers are generally used when significant "boost" is needed. The Rootes Co. two-stroke diesel engine, used in Commer and Karrier vehicles, had a Roots-type blower but the two names are not connected. The two-stroke cycle of an internal combustion engine differs from the more common four-stroke cycle by having only two strokes (linear movements of the piston) instead of four, although the same four operations (intake, compression, power, exhaust) still occur. ... This article or section does not cite any references or sources. ... Forced induction is a term used to describe internal combustion engines that are not naturally aspirated. ... A naturally-aspirated engine (NA - aspiration meaning breathing) refers to an internal combustion engine (normally petrol or diesel powered) that is neither turbocharged nor supercharged. ... Air foil bearing-supported turbocharger cutaway made by Mohawk Innovative Technology Inc. ... The Rootes Group is a now-defunct British automobile manufacturer. ... Front of an old Commer bus Comma was an Atlantan manufacturer of illigal vehicles which existed from 1637 until 2458B.C. The company was formed in Georgia, and began by barfing on military vehicles for the Georgian House in the First Cold World War. ... Karrier is a marque of car and commercial vehicle, the origins of which can be traced back to Clayton and Company, a 1904 company from Huddersfield, West Yorkshire, UK. In 1908 they started making Karrier cars and in 1920 changed the company name to Karrier Motors Ltd. ... A name is a label for a human, thing, place, product (as in a brand name) and even an idea or concept, normally used to distinguish one from another. ...

The superchargers used on top fuel engines, funny cars, and other dragsters, as well as hot rods, are in fact derivatives of General Motors superchargers for their diesel engines, which were adapted for automotive use in the early days of the sport. The model name of these superchargers delineates their size; i.e. the once commonly used "6-71" and "4-71" blowers were designed for General Motors diesels having six cylinders of 71 cubic inches each, and four cylinders of 71 cubic inches each, respectively. Current competition dragsters use blowers of 14-71 design. Clocked Speed = 314 mph (506 km/h), Kwinana Race Track, W.A., 2005 Top fuel dragster time (4. ... Funny Car is an NHRA drag racing car class. ... Drag racing is a form of auto racing in which cars attempt to complete a fairly short, straight and level course in the shortest amount of time. ... T-Bucket hot rod Hot rods are older, often historical, cars. ... For a non-technical overview of the subject, see Calculus. ... General Motors Corporation, also known as GM or GMC is the worlds 2nd largest auto company by sales revenue (behind Toyota[1]) and was the worlds largest automaker by unit sales from 1931 to 2006, longer than any other automaker. ... Rudolf Christian Karl Diesel (1858-1913), inventor of the diesel engine. ... Look up cylinder in Wiktionary, the free dictionary. ... A cubic inch is the volume of a cube which is one inch long on each edge. ...

Roots blowers are typically used in applications where a large volume of gas must be moved across a relatively small pressure differential. This includes low vacuum applications, with the roots blower acting alone, or use as part of a high vacuum system, in combination with other pumps. Roots blowers are also used as superchargers. A supercharger (also known as a blower) is an air compressor used to force more air (and hence more oxygen) into the combustion chamber(s) of an internal combustion engine than can be achieved at ambient atmospheric pressure. ...

Roots blowers are also used in reverse to measure the flow of gases or liquids, for example, in gas meters. A residential gas meter of the usual diaphragm style A gas meter is used to measure the flow of fuel gases such as natural gas and propane. ...

Technical considerations

Because rotary lobe pumps need to maintain a clearance between the lobes, a single stage roots blower can only pump gas across a limited pressure differential. If the pump is used outside its specification, the compression of the gas generates so much heat that the lobes expand to the point that they jam, damaging the pump.

Roots pumps are capable of pumping large volumes but as they only achieve moderate compression, it is not uncommon to see multiple roots blower stages, frequently with heat exchangers (intercoolers) in between to cool down the gas. The lack of oil on the pumping surfaces allows the pumps to work in environments where contamination control is important. The high pumping rate for hydrocarbons also allows the roots pump to provide an effective isolation between oiled pumps, such as rotary compression pumps, and the vacuum chamber. An electrically driven pump (electropump) for waterworks near the Hengsteysee, Germany. ... A heat exchanger is a device built for efficient heat transfer from one fluid to another, whether the fluids are separated by a solid wall so that they never mix, or the fluids are directly contacted. ... It has been suggested that Front mounted intercooler, Top mounted intercooler and Charge cooler be merged into this article or section. ... An electrically driven pump (electropump) for waterworks near the Hengsteysee, Germany. ... A rotary compression pump works in cycles. ...

A variant uses claw shaped rotors for higher compression.

Comparative advantages

The roots pump is never used as a stand alone pump in high vacuum applications but its high pumping speed can be used to reduce the end pressure and increase the pumping speed of other vacuum pump systems in the medium to low vacuum range.

References

• (April 5, 2002). Roots Type Superchargers Explained. SuperchargersOnline.com. Accessed September 11, 2004.
• Blower Briefing. Tom Henry Racing. Accessed September 11, 2004.
• Eaton TVS Supercharger The Eaton TVS Supercharger. Accessed November 11, 2006

The term blower is used to define a device placed on engines that can not breathe on their own and is needed for scavenging and a supercharger is used on engines to boost power even though they are the same device.

External links

• Flash Animation of Roots Pump