Suntec Industries Incorporated

Sundstrand Corporation

Suntex Industries Incorporated

Frank L Harwath

Dale L Hunsberger

Robert W Erikson

A fuel supply unit adapted to supply a relatively constant flow of fuel oil to an oil burner independently of the pressure of the fuel at a discharge port. The fuel supply unit includes a pump which draws fuel oil from a storage tank and which supplies pressurized fuel to an outlet chamber. The fuel then flows from the outlet chamber to the burner by way of the discharge port. A metering orifice is located between the outlet chamber and the discharge port to control the flow rate of the fuel delivered to the burner, the volumetric flow rate of fuel being related to the pressure differential across the metering orifice. A regulating valve senses the pressure of the fuel at the discharge port and adjusts the pressure of the fuel in the outlet chamber to maintain a relatively constant pressure differential across the metering orifice.

Fuel supply unit for an oil burner

A relief valve is built into the nozzle port of a fuel pump for an oil burner and opens to relieve pressure in the fuel supply line and prevent oil from dripping out of the burner nozzle when the pump is shut down. The relief valve comprises a ball which is normally held in a closed position by an arcuate leaf spring wrapped partially around the nozzle port.

Relief valve for the fuel pump of an oil burner

A gear pump includes a valve member adapted to engage a valve seat and close a control port and urged to an open position by a coil spring. In order to reduce cocking of the valve member relative to the valve seat when the valve member is closed, the end coil of the spring that engages the valve member is formed so as to be in non-parallel relation with the sealing surface of the valve seat when the spring is relaxed. As the spring is compressed during closure of the valve member, the end coil moves into parallelism with the sealing surface in order to enable the valve member to squarely engage the sealing surface.

Spring-biased valve assembly for a gear pump

A gear pump in which a gear is secured to a shaft by a press fit and by a key which fits into a slot in the shaft. The key includes radially projecting ears which fit into keyways in the bore of the gear, the keyways having bottoms facing axially toward the bottom of the slot. A hot upset at the free end of the shaft clamps the key axially between the bottom of the slot and the bottom of the keyways. When the shaft/gear/key subassembly is assembled with the body and the end plate of the pump, the gear retention elements described above coact to positively prevent the shaft from being pulled out of the body and from being thrust inwardly into contact with the end plate.

Gear pump with improved gear/shaft retention

A gear pump receives fuel oil from an intake line leading from a storage tank and supplies pressurized fuel to a regulating valve which selectively opens and closes to control the flow of fuel to an oil burner. When the pump first starts but before the regulating valve opens, fuel bypasses the regulating valve and is returned to the tank along with any air that might be in the system, the system thus being automatically purged of air. After the regulating valve opens, excess fuel which is not required by the oil burner is returned directly to the inlet of the pump for recirculation and bypasses both the seal chamber of the pump and the storage tank so as to enable low flow velocity to be maintained in the intake line leading from the tank to the pump and thereby prevent cavitation at the pump when the fuel is of high viscosity. Only a small flow of fuel is directed to the seal chamber to lubricate the shaft of the pump. A magnetic ring in the seal chamber removes metallic components from the fuel in the seal chamber by magnetic attraction and also acts as a baffle to reduce excessive wear of the shaft.

A two-stage gear pump with two gear sets each having a spur gear telescoped onto a slotted drive shaft with a press fit and also positively keyed to the shaft. An annular groove is formed around the shaft adjacent the closed end of the slot in the shaft and enables the slot to be relatively short in axial length so as to reduce manufacturing problems and to enhance the press fit between the shaft and the first stage spur gear.

Two-stage gear pump with improved spur gear mounting

A gear pump in which a drive shaft is telescoped into a bore in a spur gear and is held against rotation relative to the gear by means of a key fitting into keyways formed in the shaft and in the bore of the gear. To retain the shaft against axial movement relative to the gear, a spring steel ring is formed with a radially extending slot having a transverse width just slightly greater than the transverse width of the key. The ring is collapsed hoopwise into a groove in the shaft and is positioned such that the slot in the ring is alined axially with the keyway in the shaft. When the shaft is telescoped to a predetermined depth in the bore in the gear, the ring expands hoopwise and snaps into a groove formed in the wall of the bore. The coaction of the ring with the two grooves locks the shaft against axial movement relative to the gear.

Gear pump with ring-type shaft retainer

A gear pump includes a diaphragm-operated valve having a valve member adapted to close a control port. The valve member comprises a generally cupshaped housing, an elastomeric disc telescoped into the housing, and a sheet metal retainer plate which is pressed into the housing to hold the elastomeric disc therein. The retainer plate is formed with angularly spaced and radially projecting tabs which engage the housing to establish a tight fit between the plate and the housing. The retainer plate is formed by fine blanking a sheet of metal and, as a result of the fine blanking operation, axially projecting burrs are formed on the tabs. To prevent the burrs from piercing the diaphragm, a circumferentially extending relief groove is formed in the periphery of the retainer adjacent the tabs and results in the burrs being kept in spaced relation with the diaphragm.

Diaphragm-actuated valve for a gear pump

The regulating valve of a gear pump for an oil burner is urged to a closed position by a spring-loaded plunger. An adjusting screw is associated with the plunger and, when turned, causes the plunger to shift longitudinally so as to adjust the spring force applied to the valve. The screw is threadably received within a nut which is formed integrally with a sleeve. A pump inlet fitting extends through the sleeve to fasten the sleeve to the body of the pump. The inlet fitting and the sleeve coact to prevent rotation of the nut when the adjusting screw is turned.

Pump with valve adjusting screw

A two-stage gear pump with two gear sets each having a pinion telescoped onto a slotted drive shaft with a press fit and also positively keyed to the shaft. One key in the slot of the shaft includes radial ears establishing a positive coupling between the shaft and one of the pinions and also includes cantilevered spring fingers which enhance the press fit between the shaft and the other pinion.

Gear pump with improved pinion mounting

The pinion gear of a gear pump is press fit onto the end portion of the drive shaft of the pump and is positively captivated on the shaft by a key and by a hot upsetting process, the latter resulting in the formation of axially protruding burrs on the end face of the shaft. When the drive shaft is rammed forwardly with significant force, the burrs tend to embed in an end plate disposed in opposing relation with the shaft. To prevent the burrs from embedding in the end plate and locking the shaft against rotation, the end plate is formed with a recess which receives the burrs with substantial axial clearance when the shaft is rammed forwardly against the end plate.

Gear pump with means for preventing shaft lock-up

The present invention is directed to a fuel supply system for a fuel burner of the type that requires for proper operation an excess flow of fuel to be provided to the burner with that excess being recirculated. The fuel system further requires that sufficient fuel is added to the system to make up for that amount of fuel which is fired or burned. The fuel supply system includes a fuel pump which selectively draws from a fuel supply the make-up fuel flow and from a return path the excess fuel flow for recirculation. At any given moment all fuel flow from one inlet line and the other inlet line is positively closed.

Fuel supply system for a recirculating fuel burner

A system for supplying fuel to an atomization fuel oil burner nozzle from a fuel pump at a rate less than that rated for the nozzle for burning of less fuel while achieving good combustion. The fuel is delivered to the nozzle at a pulsing frequency which is dynamically matched to intermittent pressure pulses within the fuel pump to create resonant pressure peaks at the nozzle. The fuel pump creates a pressure pulse each time a tooth of one gear of the pump makes full penetration into the space between a pair of teeth of a coacting rotatable ring gear. Rotatable valving structure, including gear ports in the rotatable ring gear pulses fluid flow to the nozzle by alternately connecting a fluid outlet of the pump to either a pressure port within the pump at the time of a pressure pulse or to the fuel pump inlet with the pressure peak of the pulsed flow being phased together with said pressure pulse.

Liquid fuel supply system for an atomization burner nozzle

An arrangement for mounting a gear on a drive shaft of a fuel pump includes a longitudinal slot dividing one end portion of the shaft into first and second cantilever sections. Shoulders formed in the slot on the cantilever sections abut a key extending transversly through the slot to protrude from the shaft and the key is received in keyways formed in the gear diametrically of each other and opening into a cylindrical aperture. The latter is sized to receive the inner end portion of the shaft with a press fit with end walls of the keyways abutting the protruding key to locate the shaft axially within the gear. The width of the slot separating the cantilever sections of the shaft is slightly greater than the diameter of the key thereby providing clearance between the key and the cantilever sections to allow deflection of the sections during press-fitting of the shaft in the gear.

Arrangement for mounting a gear on a shaft

A fuel burner pumping system includes a pump having an inlet communicating with a fuel source and an outlet which communicates with a control valve assembly for regulating the pressure of the fuel supplied to the fuel burner nozzle or nozzles through a nozzle passage leading from an outlet port of a main chamber in the control valve assembly. High pressure fuel is pumped into the main chamber through a first outlet passage leading from the pump. A second outlet passage leading from the pump to the nozzle passage by-passes the control valve assembly so that air may be purged from the system when the pump initially is started. An air purging valve within the second outlet passage is movable between closed and open positions for blocking fuel flow through such passage during normal operation of the pump and for opening the second passage when the pump initially is started. In one form of the invention, the purging valve is operable manually and, in another form of the invention, the air purging valve operates automatically.

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Rockford, IL, United States of America

Frank L Harwath