The scroll-type supercharger is a scroll compressor used as a positive displacement orbiting-spiral supercharger. It is a compromise between the more rugged rotating lobe, and the more efficient sliding vane type superchargers, and is considered to offer the highest potential in regard to efficiency, noise and pressure fluctuation. [1]
The basic concept of the scroll-type supercharger was invented by Léon Creux of France in 1905, [2] originally for aircraft use, though Creux did consider it as a possible form of steam engine. However, Creux's supercharger failed due to the relatively poor casting techniques available at the time. This type of supercharger has not seen widespread use in the aviation role, but has been used on a small number of automotive applications.
The moving parts of the supercharger is a disc-shaped displacer with identical spirals (or scrolls) projecting from each side, and manufactured from light alloy to reduce inertia. A pair of fixed scrolls supported by the end walls of the compressor chamber are interleaved with the moving scrolls. Rather than rotating, the displacer is driven in an orbital motion to create a pumping action between the pairs of scrolls.
Air is pulled into the device when the moving scrolls are at their furthest from the fixed scrolls, leaving a large gap. As the shaft rotates the gap closes, and the point of widest opening rotates to a point further "into" the charger. As the process continues the gap eventually ends up on the middle of the housing, at the point where the higher pressure air exhausts into the engine. The scrolls are shaped so the gap slowly decreases in size as it moves to the centre, thereby compressing the air.
The edges of the scrolls are sealed by strip-type seals, while the supercharger's main shaft bearings use radial seals to prevent the charge air from becoming contaminated with oil. [3]
The most common and well known scroll-type supercharger is the G-Lader (Lader is German for charger), designed by Volkswagen for use in a version of the Mk2 Polo called the GT G40. Launched first as a limited batch of about 500 cars in 1987, most were sold to Volkswagen workers.[ citation needed ] A normal production version of the G40 was launched as part of the Mk2F range. The name comes from the "G" shape of its compression channels. It was mounted on a 1,272 cc (77.6 cu in ) petrol engine, which offered performance about that of a 2 L (122 cu in) naturally aspirated engine.
A similar, but larger G60 became available in the Volkswagen Corrado during the early 1990s, and was also available in limited numbers in the Volkswagen Passat and Volkswagen Golf. The G60 won International Engine of the Year [ citation needed ] when it was introduced in 1989.
The "40" and "60" denote the displacer scroll width in millimetres.
All supercharger types benefit from the use of an intercooler to get rid of the heat produced during compression, and therefore help increase the density of the charged air.
A turbocharger, colloquially known as a turbo, is a turbine-driven, forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra compressed air into the combustion chamber. This improvement over a naturally aspirated engine's power output is because the compressor can force more air—and proportionately more fuel—into the combustion chamber than atmospheric pressure alone.
The Wankel engine is a type of internal combustion engine using an eccentric rotary design to convert pressure into rotating motion.
The Roots-type blower is a positive displacement lobe pump which operates by pumping a fluid with a pair of meshing lobes resembling a set of stretched gears. Fluid is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The most common application of the Roots-type blower has been as the induction device on two-stroke diesel engines, such as those produced by Detroit Diesel and Electro-Motive Diesel. Roots-type blowers are also used to supercharge Otto cycle engines, with the blower being driven from the engine's crankshaft via a toothed or V-belt, a roller chain or a gear train.
A centrifugal supercharger is a specialized type of supercharger that makes use of centrifugal force in order to push fuel into an engine. Increased fuel into an engine allows the engine to burn more fuel, which results in increased power output of the engine. Centrifugal superchargers are generally attached to the front of the engine via a belt-drive or gear-drive from the engine's crankshaft.
A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. An air compressor is a specific type of gas compressor.
Forced induction is the process of delivering compressed air to the intake of an internal combustion engine. A forced induction engine uses a gas compressor to increase the pressure, temperature and density of the air. An engine without forced induction is considered a naturally aspirated engine.
The Sarich orbital engine is a type of internal combustion engine, invented in 1972 by Ralph Sarich, an engineer from Perth, Australia, which features orbital rather than reciprocating motion of its internal parts. It differs from the conceptually similar Wankel engine by using a generally prismatic shaped rotor that orbits the axis of the engine, without rotation, rather than the rotating trilobular rotor of the Wankel.
A drive shaft, driveshaft, driving shaft, tailshaft, propeller shaft, or Cardan shaft is a vehicle component for transmitting mechanical power and torque and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them.
The Mitsubishi Kasei was a two-row, 14-cylinder air-cooled radial engine built by Mitsubishi Heavy Industries and used in a variety of World War II Japanese aircraft, such as Mitsubishi J2M and Mitsubishi G4M. The Mitsubishi model designation for this engine was A10 while it was an experimental project, in service it was known as the MK4, and known as the Ha101 & Ha111 by the Army and Kasei by the Navy. According to unified designation code it was Ha-32 of the variants from 11 to 27.
The Quasiturbine or Qurbine engine is a proposed pistonless rotary engine using a rhomboidal rotor whose sides are hinged at the vertices. The volume enclosed between the sides of the rotor and the rotor casing provide compression and expansion in a fashion similar to the more familiar Wankel engine, but the hinging at the edges allows the volume ratio to increase. Unlike vane pumps, in which vane extension is generally important and against which the pressure acts to generate the rotation, the Quasiturbine contour seals have a minimal extension and the rotation does not result from pressure against these seals.
A scroll compressor is a device for compressing air or refrigerant. It is used in air conditioning equipment, as an automobile supercharger and as a vacuum pump. Many residential central heat pump and air conditioning systems and a few automotive air conditioning systems employ a scroll compressor instead of the more traditional rotary, reciprocating, and wobble-plate compressors.
The Volkswagen G60 and G40 engines are inline-four cylinder automobile petrol engines, which uses a specific method of forced induction - by way of a scroll-type supercharger. The G60 engine was formerly manufactured by the German automaker Volkswagen Group, and was installed in a limited number and range of 'hot hatch' cars from their Volkswagen Passenger Cars marque from August 1988 to July 1993.
A swing-piston engine is a type of internal combustion engine in which the pistons move in a circular motion inside a ring-shaped "cylinder", moving closer and further from each other to provide compression and expansion. Generally two sets of pistons are used, geared to move in a fixed relationship as they rotate around the cylinder. In some versions the pistons oscillate around a fixed center, as opposed to rotating around the entire engine. The design has also been referred to as a oscillating piston engine, vibratory engine when the pistons oscillate instead of rotate, or toroidal engine based on the shape of the "cylinder".
A rotary vane pump is a positive-displacement pump that consists of vanes mounted to a rotor that rotates inside a cavity. In some cases these vanes can have variable length and/or be tensioned to maintain contact with the walls as the pump rotates. It was invented by Charles C. Barnes of Sackville, New Brunswick, who patented it on June 16, 1874. There have been various improvements, including a variable vane pump for gases (1909). They are considered less suitable than other vacuum pumps for high-viscosity and high-pressure fluids, and are complex to operate. They can endure short periods of dry operation, and are considered good for low-viscosity fluids.
A rotary-screw compressor is a type of gas compressor, such as an air compressor, that uses a rotary-type positive-displacement mechanism. They are commonly used to replace piston compressors where large volumes of high-pressure air are needed, either for large industrial applications such as chillers, or to operate high-power air tools such as jackhammers and impact wrenches. For smaller rotor sizes the inherent leakage in the rotors becomes much more significant, leading to this type of mechanism being unsuitable for small air compressors.
Vapour-compression refrigeration or vapor-compression refrigeration system (VCRS), in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air-conditioning of buildings and automobiles. It is also used in domestic and commercial refrigerators, large-scale warehouses for chilled or frozen storage of foods and meats, refrigerated trucks and railroad cars, and a host of other commercial and industrial services. Oil refineries, petrochemical and chemical processing plants, and natural gas processing plants are among the many types of industrial plants that often utilize large vapor-compression refrigeration systems. Cascade refrigeration systems may also be implemented using 2 compressors.
A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing the power output.
The G-Lader is a scroll-type supercharger used in various Volkswagen Passenger Cars models. Its purpose is to increase the motive power output from the internal combustion engine attainable with a given engine displacement. Since it is not enough to simply inject more fuel, as this produces too rich an air-fuel mixture, more intake air has to be added at the same time. This can be achieved with an exhaust-driven turbocharger, or a crankshaft-driven positive displacement compressor. The G-Lader is in the compressor category, since it is crankshaft-driven and does not have the "lag" usually associated with turbocharged engines.
An internal combustion engine (ICE) is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is applied typically to pistons, turbine blades, rotor or a nozzle. This force moves the component over a distance, transforming chemical energy into useful work. This replaced the external combustion engine for applications where weight or size of the engine is important.