Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
  • F04C14/18—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber
  • F04C14/22—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members
  • F04C14/223—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam
  • F04C14/226—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam by pivoting the cam around an eccentric axis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/30—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
  • F04C2/34—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members
  • F04C2/344—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
  • F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
  • F01C21/08—Rotary pistons
  • F01C21/0809—Construction of vanes or vane holders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/30—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
  • F04C2/34—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members
  • F04C2/344—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
  • F04C2/3441—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation
  • F04C2/3442—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C2220/00—Application
  • F04C2220/24—Application for metering throughflow
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2203/00—Non-metallic inorganic materials
  • F05C2203/08—Ceramics; Oxides
  • F05C2203/0804—Non-oxide ceramics
  • F05C2203/0813—Carbides
  • F05C2203/0826—Carbides of wolfram, e.g. tungsten carbide

Definitions

• the present invention relates to a pump, and more specifically to a highspeed vane pump that finds particular use in fuel pumps, metering, and control for jet engines.
• vane pumps use materials that are of generally high durability and wear resistance due to the high velocity and loading factors encountered by these vane pumps. Parts manufactured from these materials generally cost more to produce and suffer from high brittleness.
• tungsten carbide is widely used as a preferred material for vane pump components used in jet engines. Tungsten carbide is a very hard material that finds particular application in the vane, cam ring, and side plates. However, tungsten carbide is approximately two and one-half (2 VT) times the cost of steel, for example, and any flaw or overstress can result in cracking and associated problems.
• the ratio of the weight of tungsten carbide relative to steel is approximately 1.86 so that weight becomes an importnat consideration for these types of applications.
• the weight, cost, and high brittleness associated therewith results in a substantial increase in overall cost.
• the gas turbine fuel pump includes a housing having a pump chamber and an inlet and outlet in fluid communication with the chamber.
• a rotor is received in the pump chamber and a cam member surrounds the rotor and is freely rotatable relative to the housing.
• a journal bearing is interposed between the cam member and the housing for reducing mechanical losses during operation of the pump.
• the journal bearing is a continuous annular passage defined between the cam member and the housing.
• the rotor includes circumferentially spaced vanes having outer radial tips in contact with the cam member.
• the pump further includes a cam sleeve pivotally secured within the housing to selectively vary the eccentricity between the cam member and the rotor.
• the gas turbine fuel pump exhibits dramatically improved efficiencies over conventional vane pumps that do not employ the freely rotating cam member.
• the fuel pump also exhibits improved reliability at a reduced cost since selected components can be formed of a reasonably durable, less expensive material.
• the improved efficiencies also permit the pump to be smaller and more compact which is particularly useful for selected applications where size is a critical feature.
• Figure 1 is an exploded perspective view of a preferred embodiment of the fluid pump.
• Figure 2 is a cross-sectional view through the assembled pump of Figure 1.
• Figure 3 is a longitudinal cross-sectional view through the assembled pump.
• Figure 4 is a cross-sectional view similar to Figure 2 illustrating a variable displacement pump with the support ring located in a second position.
• a pump assembly 10 includes a housing 12 having a pump chamber 14 defined therein.
• a rotor 20 Rotatably received in the chamber is a rotor 20 secured to a shaft 22 for rotating the rotor within the chamber.
• Peripherally or circumferentially spaced about the rotor are a series of radially extending grooves 24 that operatively receive blades or vanes 26 having outer radial tips that extend from the periphery of the rotor.
• the vanes may vary in number, for example, nine (9) vanes are shown in the embodiment of Figure 2, although a different number of vanes can be used without departing from the scope and intent of the present invention.
• the rotational axis of the shaft 22 and rotor 20 is referenced by numeral 30.
• Selected vanes (right-hand vanes shown in Figure 2) do not extend outwardly from the periphery of the rotor to as great an extent as the remaining vanes (left-hand vanes in Figure 2) as the rotor rotates within the housing chamber.
• Pumping chambers are defined between each of the vanes as the vanes rotate in the pump chamber with the rotor and provide positive displacement of the fluid.
• a spacer ring 40 is rigidly secured in the housing and received around the rotor at a location spaced adjacent the inner wall of the housing chamber.
• the spacer ring has a flat or planar cam rolling surface 42 and receives an anti-rotation pin 44.
• the pin pivotally receives a cam sleeve 50 that is non- rotatably received around the rotor.
• First and second lobes or actuating surfaces 52, 54 are provided on the sleeve, typically at a location opposite the anti-rotation pin. The lobes cooperate with first and second actuator assemblies 56, 58 to define means for altering a position of the cam sleeve 50.
• each actuator assembly includes a piston 60, biasing means such as spring 62, and a closure member 64 so that in response to pressure applied to a rear face of the pistons, actuating lobes of the cam sleeve are selectively moved.
• This selective actuation results in rolling movement of the cam sleeve along a generally planar or flat surface 66 located along an inner surface of the spacer ring adjacent on the pin 44. It is desirable that the cam sleeve undergo a linear translation of the centerpoint, rather than arcuate movement, to limit pressure pulsations that may otherwise arise in seal zones of the assembly.
• the center of the cam sleeve is selectively offset from the rotational axis 30 of the shaft and rotor when one of the actuator assemblies is actuated and moves the cam sleeve ( Figure 2).
• Other details of the cam sleeve, actuating surface, and actuating assemblies are generally well known to those skilled in the art so that further discussion herein is deemed unnecessary.
• a rotating cam member or ring 70 Received within the cam sleeve is a rotating cam member or ring 70 having a smooth, inner peripheral wall 72 that is contacted by the outer tips of the individual vanes 26 extending from the rotor.
• An outer, smooth peripheral wall 74 of the cam ring is configured for free rotation within the cam sleeve 50.
• a journal bearing 80 supports the rotating cam ring 70 within the sleeve.
• the journal bearing is filled with the pump fluid, here jet fuel, and defines a hydrostatic or hydrodynamic, or a hybrid hydrostatic/hydrodynamic bearing.
• the frictional forces developed between the outer tips of the vanes and the rotating cam ring 70 result in a cam ring that rotates at approximately the same speed as the rotor, although the cam ring is free to rotate relative to the rotor since there is no structural component interlocking the cam ring for rotation with the rotor. It will be appreciated that the ring rotates slightly less than the speed of the rotor, or even slightly greater than the speed of the rotor, but due to the support/operation in the fluid film bearing, the cam ring possesses a much lower magnitude viscous drag. The low viscous drag of the cam ring substitutes for the high mechanical losses exhibited by known vane pumps that result from the vane frictional losses contacting the surrounding stationary ring.
• the drag forces resulting from contact of the vanes with the cam ring are converted directly into mechanical losses that reduce the pumps overall efficiency.
• the cam ring is supported solely by the journal bearing 80 within the cam sleeve.
• the journal bearing is a continuous passage. That is, there is no interconnecting structural component such as roller bearings, pins, or the like that would adversely impact on the benefits obtained by the low viscous drag of the cam ring.
• flooded ball bearings would not exhibit the improved efficiencies offered by the journal bearing, particularly a journal bearing that advantageously uses the pump fluid as the fluid bearing.
• Figure 3 more particularly illustrates inlet and outlet porting about the rotor for providing an inlet and outlet to the pump chamber.
• First and second plates 90, 92 have openings 94, 96, respectively.
• Energy is imparted to the fluid by the rotating vanes. Jet fuel, for example, is pumped to a desired downstream use at an elevated pressure.
• the cam ring and side plates are alternately formed of a low cost, durable material such as steel to reduce the weight and manufacturing costs, and allow greater reliability.
• all of the components can still be formed of more expensive durable materials such as tungsten carbide and still achieve substantial efficiency benefits over prior arrangements.
• the jet fuel as the fluid that forms the journal bearing
• the benefits of tungsten carbide for selected components and steel for other components of the pump assembly are used to advantage. This is to be contrasted with using oil or similar hydraulic fluids as the journal bearing fluid where it would be necessary for all of the jet fuel components to be formed from steel, thus eliminating the opportunity to obtain the benefits offered by using tungsten carbide.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Rotary Pumps (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)
• Fuel-Injection Apparatus (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Friction Gearing (AREA)

Applications Claiming Priority (3)

Publications (3)

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ID=23078142

Family Applications (1)

Country Status (8)

Cited By (1)

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Citations (5)

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• 2002
  • 2002-03-27 CA CA2443367A patent/CA2443367C/en not_active Expired - Fee Related
  • 2002-03-27 WO PCT/US2002/009298 patent/WO2002081921A1/en active IP Right Grant
  • 2002-03-27 KR KR10-2003-7013097A patent/KR20040004577A/ko not_active Application Discontinuation
  • 2002-03-27 DE DE60207401T patent/DE60207401T2/de not_active Expired - Lifetime
  • 2002-03-27 CN CNB028096274A patent/CN100557244C/zh not_active Expired - Fee Related
  • 2002-03-27 JP JP2002579661A patent/JP4215515B2/ja not_active Expired - Fee Related
  • 2002-03-27 CA CA2715436A patent/CA2715436C/en not_active Expired - Fee Related
  • 2002-03-27 AT AT02728572T patent/ATE310164T1/de not_active IP Right Cessation
  • 2002-03-27 EP EP02728572A patent/EP1384005B1/de not_active Expired - Lifetime
  • 2002-03-27 CN CN2009101737372A patent/CN101968053B/zh not_active Expired - Fee Related

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