Coltec Industries, Inc.

Chandler Evans Inc.

Colt Industries Inc.

Jack G Sundberg

Raymond D Zagranski

Martin T Books

Godwin L Noell

Mihir C Desai

William H Dalton

George L Bennett

Bernard J Bisson

Paul L Haynes, Jr

John E Cygnor

Kenneth W Devins

John P Schaffner

Daniel J Conlon

Andrew Gahura

A variable displacement vane pump includes a pump housing having a cylindrical interior chamber, a cylindrical rotor member mounted for rotational movement within the interior chamber of the pump housing, a cam member mounted for pivotal movement within the interior chamber of the pump housing about a fulcrum aligned with the vertical centerline of the interior chamber, the cam member defining a cam body having a circular bore extending therethrough for receiving the rotor member, the cam body having lateral sealing lands formed thereon, the sealing lands having arcuate sealing surfaces defining segments of a cam arc through which the cam member pivots, and static cam seals supported within the interior chamber of the pump housing and oriented on each end of a chord of the cam arc, each cam seal biased into a continuous contact position with an adjacent sealing surface of the cam member.

Static cam seal for variable displacement vane pump

Variable-displacement, single-acting vane pumps in which the cylindrical cam member is adjustably supported within an outer annular cam housing to enable the cam member to be adjustably-rotated relative to the housing to adjust the geometric center of the cam chamber relative to the center of the rotor member and thereby adjust the displacement capacity of the pump between zero-flow maximum flow values. The annular housing for the cam member comprises a roller bearing assembly between its inner race surface and the cylindrical outer surface of the cam member, which minimizes the friction when the cam member is rotated during adjustment and enables the adjustment to be actuated remotely, such as by means of a small motor gear assembly.

Variable displacement vane pump adjustable by low actuation loads

A variable displacement vane pump comprising a durable rotor member having journal ends at each side of a larger diameter central vane section comprising vane slots having well areas which slidably-engage a mating vane element. The present vane pump comprise novel cylindrical ring seal elements having a unitary body which seal the faces of the cam member, and which overlap the central vane section and vane slot extensions. The seal elements include first fuel inlet passages in the inlet arc segment thereof, and fuel discharge passages in the discharge arc thereof, both of said passages being open to the vane slot extensions and to the cam chamber for the continuous supply and pressure discharge of fuel.

Variable displacement vane pump having cam seal with seal land

A variable displacement vane pump comprising a durable rotor member having journal ends at each side of a larger diameter central vane section comprising vane slots having well areas which slidably-engage a mating vane element. The present vane pump comprises an outer cylindrical cam enclosure or spacer loaded against ring seal elements to support the faces of the seal elements closely spaced from the cam faces and reduce the actuation force required for adjustment of the displacement capacity of the pump. The cam faces include a biased segment seal in the high pressure discharge arc area. The seal elements include first fuel inlet passages in the inlet arc segment thereof, and fuel discharge passages in the discharge arc segment thereof, both of said passages being open to the vane slot extensions and to the cam chamber for the continuous supply and pressure discharge of fuel.

Variable displacement vane pump having low actuation friction cam seal

A novel single acting variable displacement vane pump (VDVP) incorporating novel vanes and undervane venting which produce selective regulated pressure-loading of the vanes against the cam surface and more positive tracking in the incoming seal arc and the outgoing or discharge seal arc of the pump rather than uniform pressure balancing of the vanes throughout the 360.degree. cam chamber. The vanes incorporated into the present pumps preferably are sectional two-piece vane assemblies comprising an upper vane section which slidably supports a lower vane section and incorporates a fluid pressurizable cavity between said vane sections which, when pressurized, forces the vane sections in opposite radial directions, and which enables the vane sections to come together and integrate when the cavity is depressurized. The vane cavity is open to the fluid pressure on one side of the vanes while the undervane area of the vane slots, below the vanes, is open to the fluid pressure one the opposite side of the vanes. Thus, in the inlet seal arc area of the pump the vane cavity becomes pressurized to force the vane sections apart and force the upper vane section against the cam surface, and in the outlet or discharge seal arc area of the pump the vane cavity becomes depressurized and the undervane area of each vane slot becomes pressurized, to force the vane sections together and force the upper vane section against the cam surface.

Variable displacement vane pump with regulated vane loading

A pump comprising a durable rotor member having large diameter journal ends at each side of a central vane section comprising vane slots having well areas which slidably-engage a mating vane element. The present vane pumps comprise novel cylindrical floating ring seal elements having a support body which continuously seals the face of the cam member, and have a movable inner ring assembly which becomes pressure-loaded against the rotor journals during use, to minimize or limit axial pressure leakage while balancing or minimizing bearing load.

Variable displacement vane pump having floating ring seal

A durable, single action, variable displacement vane pump capable of undervane pumping, components thereof, and pressure balancing method. The pump comprises a cylindrical barstock rotor member having large diameter journal ends and central vane slots uniformly spaced therearound. The vane slots are elongate and have a central vane-supporting portion of maximum depth surrounded at each end by extension portions having depths which decrease axially to the surface of rotor member. The vaned rotor is rotatably supported within a unitary cam member having opposed faces and a circular bore therethrough forming a cam chamber having a continuous interior circular cam surface. The vane slot extensions in the rotor project outwardly beyond the cam chamber. An opposed pair of manifold bearings rotatably support the journal ends of the rotor and overlap the vane slot extensions to admit fluid to expanding vane bucket areas of the rotating vaned rotor and also into the vane slot extensions and undervane areas for pressure balancing purposes. Fluid passages and pressures within the pump are arranged to balance forces acting on various parts to reduce stress, improve sealing, and permit sharing of a fluid pressure source.

Variable displacement vane pump, component parts and method

A unified fuel pump assembly combines a vane-type pump and a booster stage for the inlet of the vane-type pump, in a unitary structure to substantially reduce 'windage' losses caused by relatively moving parts. The unified structure also includes an electric motor subassembly to provide motive power, and a liquid ring pump, which helps to process air bubbles through the fuel pump, is coupled to the electric motor rotor to further avoid 'windage' losses. The vane type pump relies on the use of a central shaft capable of having a substantially uniform and relatively large diameter from end to end.

Unified fuel pump assembly

A variable displacement vaned fuel pump (10) is suitable for inclusion in a fixed displacement fuel control system for a gas turbine engine. The pump includes two track elements (34,36) having cam surfaces (42) which engage cam followers (44) on a cam actuation ring (40). A link (66) having a predetermined spring load maintains the track elements in their radially inner maximum displacement positions until the vane force and pressure forces drive the track elements radially outwardly, moving the actuation ring against its spring load. Displacement of the pump is reduced in the radially outward positions of the track elements which reduces the required bypass flow to hold a head constant across a fuel metering valve and attendant fuel heating.

Vane fuel pump having reduced displacement at high speeds

A shaft seal assembly 10 for a high speed centrifugal pump has a primary seal (30) and a secondary seal (32). During normal operation the primary seal has its nose (38) in firm engagement with a seal face (28) and the secondary seal has its nose (42) in light engagement with the seal face. Upon failure of the primary seal, the nose of the secondary seal is urged into firm engagement with the seal face. An orifice (58) in the nose of the secondary seal allows for controlled leakage which indicates primary seal failure.

Fail safe high pressure shaft seal

A shaft seal assembly (2) for a fuel pump includes a seal housing (4) attached to the fuel pump housing (6). A drive shaft (10) mounted for rotation in the fuel pump housing has a sealing face (14) which is engaged by a thrust face (42) of a thrust member (40) and by a seal face (18) of a carbon face seal (20). The thrust member and the carbon face seal are positioned with a steel carrier (26) mounted in the seal housing. A universal washer (32) is located between the carrier and the rear wall of the seal housing so that the carrier may undergo universal movement in response to movements of the thrust member. Misalignments between the axis of the shaft and the axis of the seal housing result in corresponding movements of the thrust member and the carrier which enable the axis of the face seal to remain aligned with the axis of the shaft. This arrangement permits the carbon face seal to be pressure balanced so that a relatively high fuel pressure surrounding the shaft will not produce unacceptable wear of the carbon face seal.

High thrust capacity shaft seal assembly for fuel pumps

A pumping system has a main pumping unit (14) and a backup pumping unit (16) mounted in a common housing (4) and adapted to be driven by a drive member (44). The main pumping unit is connected to the drive member by a main drive coupling (68) which incorporates a reduced shear section (76) designed to fail upon a jamming or seizure of the main pumping unit. A backup drive coupling (78) connected to the backup pumping unit is adapted to be axially displaced and threadably connected to the drive member after stoppage of the main pumping unit. An actuation device (18) functions to axially displace the backup drive coupling to establish threaded engagement. When the backup drive coupling is engaged with the drive member, the backup pumping unit will provide flow.

Method and apparatus for main fuel pumping system having backup pump

A vane pump (2), with undervane pumping capability, has a housing (4,14) within which a cam ring (16) is mounted. The cam ring has a cam surface which defines a pumping cavity and which includes two diametrically opposed inlet arcs (48, 50), two diametrically opposed discharge arcs (38, 40) and seal arcs (56, 58, 60, 62) disposed between the inlet arcs and discharge arcs. A rotor (12), mounted for rotation within the housing, carries a plurality of spokes (22). Mounted upon the spokes for radially outward and inward movement are channel-shaped vanes (28) having arcuate tips (46) for engaging the cam surface. Variable volume chambers (94), which provide undervane pumping, are formed between the radially outer ends of the spokes and the vanes. The variable volume chambers communicate with intervane volumes (93) through grooves (86) on the spokes. The vane tips engage seal arcs along a line of contact (76) selected to insure that the vanes are pressure balanced.

Vane pump having spokes with channel-shaped vanes

A backup fuel pump (16) has a thermal fuse (40) positioned in a bearing. The fuse is adapted to melt at a predetermined temperature during dry running of the pump. Melting of the fuse causes a spring urged braking member (42) to screw into a shaft journal (26) and terminate operation of the pump.

Rotary pump having brake means with thermal fuse

A shaft seal assembly for an aircraft engine fuel pump has a seal housing (30) mounted upon the pump housing (32). A carbon face seal (42) is in wiping engagement with a seal face (40) on the drive shaft (36) of the pump. The carbon face seal has a recess (46) which receives a projection (44) for preventing face seal rotation. A universal washer (46), which is mounted in the seal housing in front of the carbon face seal, embodies four protuberances (48, 50, 52, 54) having bores (56, 58, 60, 62) which extend completely through the universal washer. Compression springs (64, 66) are contained in the bores and have their rear and front extremities in respective engagement with washers (70, 72) disposed on either side of the universal washer. The spring force, which is transmitted to the carbon face seal by the front washer, is overcome as pump pressure pushes the shaft toward the front of the pump. In the compressed condition, non-axial shaft alignments are accommodated by the universal washer.

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Meriden, CT, United States of America

Jack G Sundberg