FORM 2
The Patents Act 1970
(39 of 1970)
&
The Patent Rules 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
TITLE OF THE INVENTION: UNIVERSAL PUMPIMG SYSTEM FOR FUEL DISPENSING SYSTEM
APPLICANT:
LARSEN & TOUBRO LIMITED
l&T House, Ballard Estate, P.O. Box No. 278,
Mumbai, 400 001, Maharashtra
INDIA.
PREAMBLE OF THE DESCRIPTION:
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

A) TECHNICAL FIELD
[0001] The present invention generally relates to a fuel dispensing system and particularly to a pumping unit of the fuel dispensing system. The present invention more particularly relates to a pumping unit with a common housing to accommodate a vane type pump as well as a gear type pump without any modification.
B) BACKGROUND OF THE INVENTION
[0002] Generally a fuel dispenser is a machine at the fuel filling station that is used to pump fuels such as diesel, petrol, ethanol, kerosene or other types of fuel from the underground fuel tank into the fuel tank of vehicles. A typical fuel dispensing system has a pumping unit that sucks fuel from the underground fuel tank. The fuel dispensing system further includes a metering unit placed after the pumping unit to measure the quantity of the fuel delivered to the vehicles.
[0003] Traditionally, rotary vane pumps are used in the pumping unit where a rotor is placed eccentrically inside a stator. The rotor has slots in which vane blades are mounted. When the rotor is rotated inside the stator, the vane blades of the rotor are pushed radially outward so that the vane blades are pressed against the internal surface of the stator thereby generating high frictional losses. Further the fuel has a pulsating flow in these types of pumps.
[0004] In another design, gear pumps are used in the fuel dispensing pump unit where
an internal gear or a pinion is placed in an annular gear. Both the pinion and annular gear are free to rotate and the pinion drives the annular gear or vice-versa. Because of the intrinsic construction of the gear pumps, they produce less noise and the flow of the fuel is not pulsating. Also the frictional loss of the gear pumps is very less when compared to the vane pumps.

[0005] Though the vane pump produces more noise, the vane pump is preferred as it is less expensive. At the same time the gear pumps are preferred to have less noise and stable flow. Since the principles of operation for two pumps are different, they require completely different arrangement and hence traditionally the housing for two pumps had been of different size and shape.
[0006] Hence there is a need to provide a pumping unit with a common housing which can accommodate a vane type as well as gear type of arrangement with no other changes in the fuel dispensing system. Also it would be desired to standardize the design of pumping unit to facilitate ease in manufacturing.
[0007] The abovementioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECTS OF THE INVENTION
[0008] The primary object of the present invention is to develop a pumping unit with a common housing for a fuel dispensing system to accommodate a vane type pump as well as a gear type pump.
[0009] Yet another object of the present invention is to develop a common housing in the pumping unit of the fuel dispensing system to standardize the pumping unit design to facilitate ease in manufacturing.
[0010] Yet another object of the present invention is to develop a pumping unit with a common housing for a fuel dispensing system to avoid the tooling of different housings and to replace both the vane and gear pumps easily.
[0011] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.

D) SUMMARY OF THE INVENTION
[0012] The various embodiments of the present invention provide a pumping unit with universal housing to accommodate both the gear type pump and the vane type pump without any change in the pump housing. According to one embodiment of the present invention, a universal pumping system for fuel dispensing system has a housing provided with a pump chamber to receive and store a pump unit. A centrifugal chamber is connected to the pump chamber. A channel is provided between the pump chamber and the centrifugal chamber. A vortex tube is situated inside the centrifugal chamber. A vent chamber is connected to the vortex tube. Outlet of the centrifugal chamber is connected to metering unit.
{0013] The pump chamber is designed to accommodate either a gear pump unit or a
vane pump unit without any modification. The channel is designed such that the area of the channel is gradually decreased towards the inlet of the centrifugal chamber. Inlet of the centrifugal chamber has a profile on the periphery so that the radius of the centrifugal chamber is gradually reduced towards the top to release a fuel stream tangentially towards the top of the centrifugal chamber thereby creating a helical flow at the vortex tube.
[0014] According to one embodiment of the present invention, a fuel dispensing system having a pumping unit with a common housing which accommodates both vane type pump arrangement as well as gear type pump arrangement. According to one embodiment of the present invention, a fuel dispensing system includes a pumping unit, a metering unit, a discharge nozzle and a fuel tank. The pumping unit includes a housing for the pump, a centrifugal chamber, a vent chamber and a vortex tube. The pumping unit includes either a vane pump or a gear pump. The pumping unit sucks the fuel from the underground fuel tank and pumps the fuel into the centrifugal chamber using the vane pump or the gear pump. The housing of the pumping unit is designed in such a way that the area of the channel joining the pump casing and the centrifugal chamber is gradually decreasing. The inlet of centrifugal chamber has a profile at the inlet of the centrifugal

chamber with gradually changing the radii on its periphery. At the centre of the centrifugal chamber, the vortex tube is placed and connected to the vent chamber. The outlet of the centrifugal chamber is connected to metering unit.
[0015] When the pumping unit pumps the fuel from the fuel tank to the centrifugal chamber, the fuel may contain traces of air and fuel vapour. The profile in the centrifugal chamber releases the fuel stream tangentially to the outlet of the centrifugal chamber to form helical flow of fuel is in the centrifugal chamber. In this helical flow, the aerated fuel tends to remain in the central region of the centrifugal chamber while the dense fuel without air remains at the periphery of the centrifugal chamber and hence the fuel is separated into two phases. The aerated fuel is collected by the vortex tube and is delivered to the vent chamber. In the vent chamber, the air and the fuel vapour are separated from the fuel and accumulated on the top of the vent chamber. While, the dense fuel at the periphery of the centrifugal chamber passes to metering unit.
E) BRIEF DESCRIPTION OF THE DRAWINGS:
[0016] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0017] FIG. 1 illustrates a front view of a fuel dispensing system provided with a universal pumping system for vane and gear pumps, according to one embodiment of the present invention.
[0018] FIG. 2 illustrates a side perspective view of a common housing of a pumping unit suitable for fitting both vane and gear type pump arrangements in the fuel dispensing system according to one embodiment of the present invention.

[0019] FIG. 3 illustrates a front perspective view of a universal pumping system built with a vane type pump arrangement in the fuel dispensing system according to one embodiment of the present invention.
[0020] FIG. 4 illustrates a front perspective view of a universal pumping system built with a gear type pump arrangement in the fuel dispensing system according to one embodiment of the present invention.
[0021] Although the specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0022] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0023] The various embodiments of the present invention provide a pumping unit with universal housing to accommodate both the gear type pump and the vane type pump without any change in the pump housing. According to one embodiment of the present invention, a universal pumping system for fuel dispensing system has a housing provided with a pump chamber in which pump unit is mounted. A centrifugal chamber is connected to the pump chamber. A channel is provided between the pump chamber and the centrifugal chamber. A vortex tube is connected to the centrifugal chamber. A vent chamber is

connected to the vortex tube and an outlet of centrifugal chamber is connected to metering unit.
[0024] The pump chamber is designed to accommodate either a gear pump unit or a vane pump unit without any modification. The channel is designed such that the area of the channel is gradually decreased towards the inlet of the centrifugal chamber to release a fuel stream tangentially towards the top of the centrifugal chamber thereby creating a helical flow.
[0025] According to one embodiment of the present invention, a fuel dispensing system having a pumping unit with a common housing which accommodates both vane type arrangement as well as gear type arrangement. According to one embodiment of the present invention, a fuel dispensing system includes a pumping unit, a metering unit, a discharge nozzle and a fuel tank. The pumping unit sucks the fuel from underground tank and pumps the fuel into the metering unit. The metering unit is mounted on the pumping unit to measure the amount of fuel. The metering unit and the discharge nozzle are connected by a hose. The fuel is carried from the metering unit to the hose and then finally delivered to the discharge nozzle.
[0026] The pumping unit includes housing for the pump, a centrifugal chamber, a vent chamber, and a vortex tube. The housing of the pumping unit is built with a vane pump or a gear pump. The vane pump includes a rotor with a plurality of slots, a stator or adapter, a pump head and a plurality of vane blades. Each vane blade is seated in each slot. The rotor is mounted eccentrically in the adapter. The rotor has a shaft running axially through it and the shaft projects out of the whole housing. A pulley is mounted on the shaft which is driven by a motor. The whole assembly of the vane pump is situated in an enclosure formed by the pump head and the adapter.

[0027] As the rotor turns, the fuel is trapped between the pockets formed between the successive vane blades and the stator. The vane blades propel the fuel forward from the inlet of the pumping unit. The displacement of the fuel creates a partial vacuum at the inlet of the pumping unit. This trapped pocket is compressed and pressurized as it moves towards outlet. Thus a flow formed by successive pressurized pockets is delivered from outlet of pumping unit,
[0028] In the gear pump arrangement, the gear pump includes an internal pinion gear with a shaft, an annular gear and a crescent. The internal pinion gear is running through the gear pump axially. The internal pinion gear has a multitude of profiled teeth arranged equi-spaced throughout. The internal pinion gear is mounted eccentrically with the annular gear. The annular gear has a multitude of profiled cavities arranged equi-spaced to accommodate the teeth of the internal pinion gear. The number of the cavities in the annular gear is more than the number of teeth in the internal pinion gear. According to one embodiment of the present invention, drive from motor is given to inner pinion gear which in turn rotates outer annular gear. In another variant of gear type arrangement, the drive from the motor is given to the annular gear having the number of cavities thereby rotating the internal pinion gear.
[0029] In both variants of the gear type arrangements, the crescent is arranged in such a way that as the internal pinion gear or the annular gear rotates, the fuel pockets are formed in between the upper face of crescent and successive pinion gear teeth as well as the lower surface of crescent and the successive annular gear teeth. These fuel pockets are further pressurized and delivered to the outlet of the pumping unit.
[0030] The housing of the pumping unit includes an inlet, an outlet, a cylindrical room for the pump and a centrifugal chamber. The cylindrical room provides a common space to accommodate the vane pump as well as the gear pump. The housing is designed in such a way that the area of the channel joining the pump casing and the centrifugal chamber is gradually decreasing. Also there is a profile at the inlet of the centrifugal chamber with

gradually changing the radii on its periphery which releases the fuel stream tangentially to the top of the centrifugal chamber.
[0031] The vortex tube is placed at the geometric centre of the centrifugal chamber and connected to the vent chamber. The outlet of the centrifugal chamber is connected to metering unit.
[0032] When the pumping unit pumps the fuel from the fuel tank, the fuel may contain traces of air and fuel vapour. A helical flow of fuel is created in the centrifugal chamber upon the fuel enters into the centrifugal chamber tangentially. The helical flow of the fuel results into the formation of vortex of the aerated fuel. As a result, the aerated fuel tends to remain in the central region of the centrifugal chamber while the dense fuel without air remains at the periphery of the centrifugal chamber and hence the fuel is separated into two phases. The aerated fuel is collected by the vortex tube and is delivered to the vent chamber. In the vent chamber, the air and the fuel vapour are separated from the fuel and accumulated on the top of the vent chamber. At the same time, the dense fuel at the periphery of the centrifugal chamber passes to metering unit.
[0033] FIG. 1 illustrates a front perspective view of a fuel dispensing system according to one embodiment of the present invention. With respect to FIG. 1, a fuel dispensing system 100 includes a pumping unit 102, a motor 104, a metering unit 106, a hose 108 and a discharge nozzle 110. The pumping unit 102 sucks the fuel from underground tank and pumps the fuel into the metering unit 106 using the drive from motor 104. The metering unit 106 is mounted on the pumping unit 102 to measure the quantity of the fuel pumped. The metering unit 106 and the discharge nozzle 110 are connected by the hose 108. The fuel is carried from the metering unit 106 to the hose 108 and then finally delivered to the discharge nozzle 110.

[0034] FIG. 2 illustrates a side perspective view of a common housing of a pumping unit suitable for fitting both vane and gear type pump arrangements in the fuel dispensing system according to one embodiment of the present invention. With respect to FIG. 2, a housing of the pumping unit 200 includes an inlet 202, an outlet, a cylindrical room 204, a centrifugal chamber 206, a vent chamber 208. The inlet 202 receives the fuel from the fuel tank. The cylindrical room 204 provides a common space to accommodate either a vane pump or a gear pump.
[0035] The housing 200 is designed in such a way that the area of the channel joining the pump casing and the centrifugal chamber 206 is gradually decreasing. Also there is a profile at the inlet of the centrifugal chamber 206 with gradually changing the radii on its periphery. At the geometric centre of the centrifugal chamber 206, a vortex tube is placed and connected to the vent chamber 208. The outlet of the centrifugal chamber 206 is connected to the metering unit 106 through opening 212.
[0036] When the pump pumps the fuel from the fuel tank to the centrifugal chamber 206, the fuel may contain traces of air and fuel vapour. The profile in the centrifugal chamber 206 releases the fuel stream tangentially to the outlet of the centrifugal chamber 206. A helical flow of fuel is created in the centrifugal chamber 206. The helical flow of the fuel results into the formation of vortex of the aerated fuel. As a result, the aerated fuel tends to remain in the central region of the centrifugal chamber 206 while the dense fuel without air remains at the periphery of the centrifugal chamber 206 and hence the fuel is separated into two phases. The aerated fuel is collected by the vortex tube and is delivered to the vent chamber 208. In the vent chamber 208, the air and the fuel vapour are separated from the fuel and accumulated on the top of the vent chamber 208. At the same time, the dense fuel at the periphery of the centrifugal chamber 206 passes to the metering unit 106 through opening 212.

[0037] FIG. 3 illustrates a front side view of a common housing of a pumping unit built with a vane type pump arrangement in the fuel dispensing system according to one embodiment of the present invention. With respect to FIG. 3, a housing of the pumping unit includes a vane pump 402 built in the cylindrical room, inlet and outlet and a centrifugal chamber 206. The vane pump 402 includes a rotor 404 with a plurality of slots 406, a plurality of vane blades 408 and a stator 410. Each vane blade 408 is seated in each slot 406. The rotor 404 is mounted eccentrically in the stator 410. Further the rotor 404 has a shaft 412 running axially through it and the shaft 412 projects out of the whole housing. A pulley is mounted on the shaft 412 which is driven by a motor.
[0038] As the rotor 404 turns, the fuel is trapped between the pockets formed by the vane blades 408 and the stator 410. The vane blades 408 propel the fuel forward from the inlet of the pumping unit. The displacement of the fuel creates a partial vacuum at the inlet of the pumping unit. Hence the fuel is continuously trapped and moved from the inlet of the pumping unit. The output fuel is pressurized and delivered to the centrifugal chamber 206.
[0039] FIG. 4 illustrates a front side view of a common housing of a pumping unit built with a gear type pump arrangement in the fuel dispensing system according to one embodiment of the present invention. With respect to FIG. 4, a housing of the pumping unit includes a gear pump 502 built in the cylindrical room, inlet and outlet and a centrifugal chamber 206. The gear pump 502 includes an internal pinion gear 504 with a shaft 506, an annular gear 508 and a crescent 510. The internal pinion gear 504 is running through the gear pump 502 axially. Further the internal pinion gear 504 has a multitude of profiled teeth 512 arranged equi-spaced throughout. The internal pinion gear 504 is mounted eccentrically with the annular gear 508. The annular gear 508 has a multitude of profiled cavities 514 arranged equi-spaced to accommodate the teeth 512 of the internal pinion gear 504. The number of the cavities 534 in the annular gear 508 is more than the number of teeth 512 in the internal pinion gear 504. According to one embodiment of the present invention, drive from motor is given to inner pinion gear 504 which in turn rotates outer annular gear 508.

In another variant of gear type arrangement, the drive from the motor is given to the annular gear 508 having the number of cavities 514 thereby rotating the internal pinion gear 504.
[0040] In both variants of the gear type arrangements, the crescent 510 is arranged in such a way that as the internal pinion gear 504 or the annular gear 508 rotates, the fuel pockets are formed in between the upper face of crescent 510 and the internal pinion gear teeth 512 as well as the lower surface of crescent 510 and the annular gear teeth. These fuel pockets are further pressurized and delivered to the centrifugal chamber 206.
[0041] When the pumping unit pumps the fuel from the fuel tank to the centrifugal
chamber 206, the fuel may contain traces of air and fuel vapour. The profile in the centrifugal chamber 206 releases the fuel stream tangentially to the outlet of the centrifugal chamber 206. A helical flow of fuel is created in the centrifugal chamber 206. The helical flow of the fuel results into the formation of vortex of the aerated fuel. As a result, the aerated fuel tends to remain in the central region of the centrifugal chamber 206 while the dense fuel without air remains at the periphery of the centrifugal chamber 206 and hence the fuel is separated into two phases. The aerated fuel is collected by the vortex tube 804 and is delivered to the vent chamber 208. In the vent chamber 208, the air and the fuel vapour are separated from the fuel and accumulated on the top of the vent chamber 208. At the same time, the dense fuel at the periphery of the centrifugal chamber 206 passes to the metering unit 106 through opening 212.
G) ADVANTAGES OF THE INVENTION
[0042] The various embodiments of the present invention provide a fuel dispensing system having a pumping unit with a common housing which accommodates both vane type arrangement as well as gear type arrangement. According to one embodiment of the

present invention, the fuel dispensing system meets the customer specification of the pumping unit by providing a singular pumping unit arrangement. The fuel dispensing system offers a housing design which accommodates both the vane and gear type arrangement in the same housing so that either of design is offered with minimal changes. Both the vane pump and gear pump arrangements are compact in size due to the usage of same housing. There is no additional investment required in the tooling of the different housings for both vane and gear type pumping arrangements. Also the fuel dispensing system having a pumping unit with a common housing standardizes the design of the pumping unit to facilitate ease in manufacturing. Since there is a standardization of the pumping unit, the variety of components is reduced drastically. Also universal housing ensures that it can be cost effective solution as a vane pump and also to provide a silent and non pulsating flow in gear type of arrangement.
[0043] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0044] It is also to be understood that the following claims are intended to cover all of
the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1. A universal pumping system for fuel dispensing system comprising:
a housing;
a pump chamber provided in the housing to receive and store a pump unit;
a centrifugal chamber connected to the pump chamber;
a channel provided between the pump chamber and the centrifugal chamber;
a vortex tube connected to the centrifugal chamber;
a vent chamber connected to the vortex tube; and
wherein the pump chamber is designed to accommodate either a gear pump unit or a
vane pump unit without any modification.