Rotary Vane Pump
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A rotary vane pump is a type of
positive-displacement pump A pump is a device that moves fluids (liquids or gases), or sometimes Slurry, slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy. Mechanical pumps serve in a wide range of application ...
that consists of vanes mounted to a
rotor ROTOR was an elaborate air defence radar system built by the British Government in the early 1950s to counter possible attack by Soviet bombers. To get it operational as quickly as possible, it was initially made up primarily of WWII-era syst ...
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. This type of pump is considered less suitable than other
vacuum pump A vacuum pump is a type of pump device that draws gas particles from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke, and was preceded by the suction pump, which dates to ...
s for high-viscosity and high-pressure fluids, and is . They can endure short periods of dry operation, and are considered good for low-viscosity fluids.


Types

The simplest vane pump has a circular rotor rotating inside a larger circular cavity. The centers of these two circles are offset, causing eccentricity. Vanes are mounted in slots cut into the rotor. The vanes are allowed a certain limited range of movement within these slots such that they can maintain contact with the wall of the cavity as the rotor rotates. The vanes may be encouraged to maintain such contact through means such as springs,
gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...
, or
centrifugal force Centrifugal force is a fictitious force in Newtonian mechanics (also called an "inertial" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It appears to be directed radially away from the axi ...
. A small amount of
oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...
may be present within the mechanism to help create a better seal between the tips of the vanes and the cavity's wall. The contact between the vanes and the cavity wall divides up the cavity into "vane chambers" that do the pumping work. On the suction side of the pump, the vane chambers are increased in volume and are thus filled with fluid forced in by the inlet vacuum pressure, which is the pressure from the system being pumped, sometimes just the atmosphere. On the discharge side of the pump, the vane chambers decrease in volume, compressing the fluid and thus forcing it out of the outlet. The action of the vanes pulls through the same volume of fluid with each rotation. Multi-stage rotary-vane vacuum pumps, which force the fluid through a series of two or more rotary-vane pump mechanisms to enhance the pressure, can attain vacuum pressures as low as 10−6 bar (0.1 Pa).


Uses

Vane pumps are commonly used as high-pressure
hydraulic pump A hydraulic pump is a mechanical source of power that converts mechanical power into hydraulic energy ( hydrostatic energy i.e. flow, pressure). Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic. They gen ...
s and in automobiles, including supercharging, power-steering,
air conditioning Air conditioning, often abbreviated as A/C (US) or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior temperature, and in some cases, also controlling the humidity of internal air. Air c ...
, and automatic-transmission pumps. Pumps for mid-range pressures include applications such as carbonators for fountain soft-drink dispensers and espresso coffee machines. Furthermore, vane pumps can be used in low-pressure gas applications such as
secondary air injection Secondary air injection (commonly known as air injection) is a vehicle emissions control strategy introduced in 1966, wherein fresh air is injected into the exhaust stream to allow for a fuller secondary combustion of exhaust gases. Development ...
for auto exhaust emission control, or in low-pressure
chemical vapor deposition Chemical vapor deposition (CVD) is a vacuum deposition method used to produce high-quality, and high-performance, solid materials. The process is often used in the semiconductor industry to produce thin films. In typical CVD, the wafer (electro ...
systems. Rotary-vane pumps are also a common type of
vacuum pump A vacuum pump is a type of pump device that draws gas particles from a sealed volume in order to leave behind a partial vacuum. The first vacuum pump was invented in 1650 by Otto von Guericke, and was preceded by the suction pump, which dates to ...
, with two-stage pumps able to reach pressures well below 10−6 bar. These are found in such applications as providing braking assistance in large trucks and diesel-powered passenger cars (whose engines do not generate intake vacuum) through a braking
booster Booster may refer to: Amusement rides * Booster (Fabbri ride), a pendulum ride * Booster (HUSS ride), an evolution of the Breakdance ride * Booster (KMG ride), a pendulum ride Arts, entertainment, and media Fictional characters * Booster, a cha ...
, in most light aircraft to drive gyroscopic
flight instruments Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with data about the flight situation of that aircraft, such as altitude, airspeed, vertical speed, heading and much more other crucial information in f ...
, in evacuating refrigerant lines during installation of
air conditioner Air conditioning, often abbreviated as A/C (US) or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior temperature, and in some cases, also controlling the humidity of internal air. Air c ...
s, in laboratory freeze dryers, and
vacuum A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressur ...
experiments in physics. In the vane pump, the pumped gas and the oil are mixed within the pump, and so they must be separated externally. Therefore, the inlet and the outlet have a large chamber, perhaps with swirl, where the oil drops fall out of the gas. Sometimes the inlet has
louver A louver (American English) or louvre (Commonwealth English; American and British English spelling differences#-re, -er, see spelling differences) is a window blind or window shutter, shutter with horizontal wikt:slat, slats that are angle ...
s cooled by the room air (the pump is usually 40 K hotter) to condense cracked pumping oil and water, and let it drop back into the inlet. When these pumps are used in high-vacuum systems (where the inflow of gas into the pump becomes very low), a significant concern is contamination of the entire system by molecular oil back streaming.


History

Like many simple mechanisms, it is unclear when the rotary vane pump was invented.
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 desig ...
's 1588 book ''Le diverse et artificiose machine del capitano Agostino Ramelli'' ("The Various and Ingenious Machines of Captain Agostino Ramelli") contains a description and an engraving of a rotary vane pump along with other types of rotary pumps, which suggests that the design was known at the time. In more recent times, vane pumps also show up in 19th-century patent records. In 1858, a US patent was granted to one W. Pierce for "a new and useful Improvement in Rotary Pumps", which acknowledged as
prior art Prior art (also known as state of the art or background art) is a concept in patent law used to determine the patentability of an invention, in particular whether an invention meets the novelty and the inventive step or non-obviousness criteria f ...
sliding blades "used in connection with an eccentric inner surface". In 1874, a Canadian patent was granted to Charles C. Barnes of
Sackville, New Brunswick Sackville is a former town in southeastern New Brunswick, Canada. It held town status prior to 2023 and is now part of the town of Tantramar, New Brunswick, Tantramar. Sackville is home to Mount Allison University, a primarily undergraduate libe ...
. There have been various improvements since, including a variable vane pump for gases (1909).


Variable-displacement vane pump

One of the major advantages of the vane pump is that the design readily lends itself to become a variable-displacement pump, rather than a fixed-displacement pump such as a spur-gear or a
gerotor A gerotor is a positive displacement pump. The name ''gerotor'' is derived from "generated rotor (turbine), rotor." A gerotor unit consists of an inner and an outer rotor. The inner rotor has ''n'' teeth, while the outer rotor has ''n'' + 1 ...
pump. The centerline distance from the rotor to the eccentric ring is used to determine the pump's displacement. By allowing the eccentric ring to pivot or translate relative to the rotor, the displacement can be varied. It is even possible for a vane pump to pump in reverse if the eccentric ring moves far enough. However, performance cannot be optimized to pump in both directions. This can make for a very interesting hydraulic-control oil pump. A variable-displacement vane pump is used as an energy-saving device and has been used in many applications, including automotive transmissions, for over 30 years.Vane Pumps: DAE Pumps' Rotary Vane & Vacuum Pumps. Retrieved from: https://www.daepumps.comRotary Vane Pump Guide & Sliding Vane Pump Design , Castle Pumps. Retrieved from: https://www.castlepumps.comWhat is a Rotary Vane Pump and How Does it Work? - Anderson Process. Retrieved from: https://www.andersonprocess.com


Materials

* Externals (head, casing) – cast iron, ductile iron, steel, brass, plastic, and stainless steel * Vane, pushrods – carbon graphite,
PEEK Polyether ether ketone (PEEK) is a beige coloured organic thermoplastic polymer in the polyaryletherketone (PAEK) family, used in engineering applications. It was invented in November 1978 and brought to market in the early 1980s by part of I ...
* End plates – carbon graphite * Shaft seal – component mechanical seals, industry-standard cartridge mechanical seals, and magnetically driven pumps * Packing – available from some vendors, but not usually recommended for thin liquid service


See also

*
Guided-rotor compressor The guided-rotor compressor (GRC) is a positive-displacement rotary gas compressor. The compression volume is defined by the trochoidally rotating rotor mounted on an eccentric drive shaft with a typical 80 to 85% adiabatic efficiency. History T ...
*
Powerplus supercharger The Powerplus is a design of supercharger that was used to boost the performance of car engines in the 1930s. It is a mechanically driven supercharger#Positive displacement, positive displacement pump, operating on the rotary vane pump, sliding- ...

Dry rotary vane pump diagram


References

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External links


Vane Pump Animation
Pumps Canadian inventions