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
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
  • F04C2/102—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member the two members rotating simultaneously around their respective axes
• • 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
  • F01C21/10—Outer members for co-operation with rotary pistons; Casings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
  • F02M37/04—Feeding by means of driven pumps
  • F02M37/041—Arrangements for driving gear-type pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M37/00—Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines
  • F02M37/04—Feeding by means of driven pumps
  • F02M37/08—Feeding by means of driven pumps electrically driven
• • 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
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
  • F04C15/0023—Axial sealings for working fluid
  • F04C15/0026—Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps
• • 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
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
  • F04C15/0034—Sealing arrangements in rotary-piston machines or pumps for other than the working fluid, i.e. the sealing arrangements are not between working chambers of the machine
• • 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
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/082—Details specially related to intermeshing engagement type machines or pumps
  • F04C2/086—Carter
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
  • F02M2200/16—Sealing of fuel injection apparatus not otherwise provided for
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
  • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
  • F02M59/04—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps
  • F02M59/06—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps with cylinders arranged radially to driving shaft, e.g. in V or star arrangement
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
  • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
  • F02M59/10—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive
  • F02M59/102—Mechanical drive, e.g. tappets or cams
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
  • F02M63/02—Fuel-injection apparatus having several injectors fed by a common pumping element, or having several pumping elements feeding a common injector; Fuel-injection apparatus having provisions for cutting-out pumps, pumping elements, or injectors; Fuel-injection apparatus having provisions for variably interconnecting pumping elements and injectors alternatively
  • F02M63/0225—Fuel-injection apparatus having a common rail feeding several injectors ; Means for varying pressure in common rails; Pumps feeding common rails
  • F02M63/0265—Pumps feeding common rails
• • 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
  • F04C11/00—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations
  • F04C11/005—Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type; Pumping installations of dissimilar working principle
• • 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
  • F04C2210/00—Fluid
  • F04C2210/10—Fluid working
  • F04C2210/1044—Fuel

Definitions

• the present invention relates to a pumping assembly to feed fuel, preferably diesel fuel, to an internal combustion engine.
• the present invention relates to a pumping assembly of the type comprising a high-pressure pump, for example a piston pump, designed to feed the fuel to an internal combustion engine; and a pre-feed pump designed to feed the fuel from a storage tank to the high-pressure pump.
• a high-pressure pump for example a piston pump
• a pre-feed pump designed to feed the fuel from a storage tank to the high-pressure pump.
• the pumping assembly is further provided with a hydraulic circuit comprising a first branch for connecting together the storage tank and the pre-feed pump, a second branch for connecting together the pre-feed pump and the high-pressure pump, and a third branch for connecting together the high-pressure pump and the internal combustion engine.
• the pre-feed pump is an electric gear pump provided with a containing casing comprising a cup-shaped pump body and a closing lid to close said pump body.
• the containing casing houses internally a synchronous, brushless, permanent- magnet, electric motor, comprising an annular-shaped stator, which has a plurality of copper windings distributed uniformly about a longitudinal axis thereof, and is provided with an electrical connector to feed said windings.
• the electric motor further comprises an annular-shaped rotor, which is engaged in a rotary manner in the stator through the interposition of a support bearing, and is mounted so as to rotate about a rotation axis coinciding with the longitudinal axis of said stator.
• the rotor has inner teeth and defines an outer gear of the gear pump, which further comprises an annular-shaped inner gear housed inside the rotor.
• the inner gear is mounted so as to rotate about a rotation axis which is eccentric with respect to the rotation axis of the rotor, and has outer teeth meshing with the inner teeth of said rotor.
• the two sets of teeth are formed so as to define a plurality of variable-volume chambers, which are distributed about the rotation axis of the rotor, and are coupled together in a fluid-tight manner.
• each variable-volume chamber is connected hydraulically in succession firstly to a fuel inlet into the gear pump and then to a fuel outlet from said gear pump.
• the rotor further comprises a plurality of pockets, which are configured to each house inside them a respective permanent magnet and are distributed about the rotation axis of said rotor.
• the stator is coated completely with a layer of isolating plastic material.
• the known pumping assemblies of the type described above have a number of disadvantages, mainly arising from the fact that the coating of the stator with said layer of isolating plastic material is relatively expensive, difficult to implement, and has a relatively low reliability in that it is unable to ensure correct isolation of the stator under the operative pressure and temperature conditions to which the gear pump is subjected.
• Figure 1 is a hydraulic diagram of a preferred embodiment of the pumping assembly of the present invention
• Figure 2 is an exploded perspective view of a detail of the pumping assembly shown in Figure 1;
• Figure 3 is a longitudinal section of the detail shown in Figure 3; and
• Figure 4 is a front view of a detail shown in Figures 2 and 3.
• 1 denotes in its entirety a pumping assembly to feed fuel, preferably diesel fuel, from a storage tank 2 to an internal combustion engine 3, in the case in question a diesel combustion engine comprising a fuel distribution manifold 4, commonly referred to by the term “common rail”, and a plurality of injectors 5 connected to the manifold 4 and designed to atomize the fuel inside associated combustion chambers (not shown) of said engine 3.
• fuel preferably diesel fuel
• common rail commonly referred to by the term "common rail”
• injectors 5 connected to the manifold 4 and designed to atomize the fuel inside associated combustion chambers (not shown) of said engine 3.
• the pumping assembly 1 comprises a high-pressure pump 6, in the case in question a piston pump, designed to feed the fuel to the engine 3, and a low- pressure or pre-feed pump 7 designed to feed the fuel from the tank 2 to the pump 6.
• the pump 6 comprises a plurality of cylinders 8 (in the case in question two cylinders 8) which are formed in a pump body 9 and are each slidably engaged by a respective piston 10.
• the pistons 10 are displaced along the associated cylinders 8 by an actuating device 11 of the known type housed inside the pump body 9 with an alternating rectilinear movement comprising an outward stroke for drawing the fuel into the associated cylinders 8 and a return stroke for compressing the fuel contained in said associated cylinders 8.
• the pumping assembly 1 further comprises a hydraulic circuit 12 to feed the fuel comprising, in turn, a first branch 13 for connecting together the tank 2 and the pump 7; a second branch 14, which connects together the pumps 6 and 7, extends through the pump body 9 in order to lubricate the actuating device 11 and is connected to each cylinder 8 by means of an associated intake valve 15; and a third branch 16 which extends between the pump 6 and the manifold 4 and is connected to each cylinder 8 by means of an associated delivery valve 17.
• a hydraulic circuit 12 to feed the fuel comprising, in turn, a first branch 13 for connecting together the tank 2 and the pump 7; a second branch 14, which connects together the pumps 6 and 7, extends through the pump body 9 in order to lubricate the actuating device 11 and is connected to each cylinder 8 by means of an associated intake valve 15; and a third branch 16 which extends between the pump 6 and the manifold 4 and is connected to each cylinder 8 by means of an associated delivery valve 17.
• the branch 14 is provided with a device 18 for filtering the fuel fed to the pump 6 and with a metering electrovalve 19 which is mounted upstream of the valves 15 in a direction 20 of feeding of the fuel along the branches 13, 14 and 16 and is movable between a closed position and an open position for selectively controlling the instantaneous fuel flow fed to the pump 6 depending on the values of a plurality of operating parameters of the engine 3.
• the circuit 12 further comprises a fourth branch 21 which extends between the manifold 4 and the tank 2 and is provided with a metering electrovalve 22 which cooperates with the electrovalve 19 in order to selectively control the fuel flow fed to the injectors 5 and allows the amount of fuel exceeding that required by the injectors 5 to be discharged into the tank 2.
• the pump 7 is an electric gear pump provided with a containing casing 23 comprising a pump body 24, which has a cup shape, is delimited by a bottom wall 25 and by a free end face 26 which are opposite one another and parallel to one another, and is closed by a lid 27 arranged in contact with said face 26.
• the casing 23 houses internally a synchronous, brushless, permanent-magnet, electric motor 28, comprising an annular-shaped stator 29, which has a longitudinal axis 30 perpendicular to the wall 25 and to the face 26, is provided with a plurality of copper windings 31, which are distributed uniformly about the axis 30, and is provided with an electrical connector 32 for feeding said windings 31.
• the stator 29 is engaged in a rotary manner by an annular-shaped rotor 33, which is mounted coaxially with the axis 30, has inner teeth 34, and defines an outer gear of the pump 7.
• the pump 7 further comprises an annular-shaped inner gear 35, which is housed inside the rotor 33, is mounted so as to rotate about a rotation axis 36 parallel to, and separate from, said axis 30, and has outer teeth 37 meshing with the inner teeth 34 of the rotor 33.
• the two sets of teeth 34, 37 are formed so as to define a plurality of variable-volume chambers 38, which are distributed about the axis 30 and are coupled together in a fluid-tight manner.
• each chamber 38 is connected hydraulically in succession firstly to a fuel inlet 39 into the pump 7 and then to a fuel outlet 40 from said pump 7.
• the volume of the chambers 38 associated with the inlet 39 increases in a direction 41 of rotation of the rotor 33 about the axis 30 and of the gear 35 about the axis 36, and that the volume of the chambers 38 associated with the outlet 40 diminishes in the direction 41 so as to compress the fuel contained therein.
• the rotor 33 is coupled to the stator 29 in a rotary manner through the
• a cylindrical support bearing 42 which is made of a plastic material and extends between the wall 25 and the lid 27.
• the bearing 42 is blocked axially against the wall 25 by the lid 27 and is fitted on a centring block 43, which projects from the wall 25 towards the lid 27 coaxially with the axis 30, has a diameter which is substantially the same as the diameter of the bearing 42, and is provided with an end pin 44 engaged through the gear 35 coaxially with the axis 36.
• the bearing 42 has a plurality of reinforcing ribs 45, which are formed on an outer surface of the bearing 42, are distributed uniformly about the axis 30, and each extend between two mutually adjacent respective windings 31 to angularly block the bearing 42 about said axis 30.
• the bearing 42 projects axially from the rotor 33 and has an annular flange 46, which projects radially inwards from the side wall of the bearing 42, extends between the lid 27 and the rotor 33 perpendicularly to the axis 30, and defines an opening which is designed to receive a centring shank 47 of the lid 27.
• the bearing 42 is coupled to the block 43 in a fluid-tight manner by means of an annular gasket 48, which extends coaxially with the axis 30 and is mounted between an outer surface of the block 43 and an inner surface of the bearing 42, that is to say between two surfaces parallel to said axis 30.
• the bearing 42 is coupled to the lid 27 in a fluid-tight manner by means of an annular gasket 49, which extends coaxially with the axis 30 and is mounted between the lid 27 and the flange 46, that is to say between two surfaces perpendicular to said axis 30.
• the flange 46 is dispensed with and the gasket 49 is mounted between an outer surface of the lid 27 and an inner surface of the bearing 42, that is to say between two surfaces parallel to the axis 30.
• the gaskets 48 and 49 ensure correct isolation of the stator 29 from the fuel present in the variable-volume chambers 38 under the operative pressure and temperature conditions to which the pump 7 is subjected, and therefore have a relatively high reliability.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Fuel-Injection Apparatus (AREA)
• Rotary Pumps (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=55699710

Family Applications (1)

Country Status (4)

Cited By (4)

Families Citing this family (1)

Citations (6)

Family Cites Families (3)

• 2015
  • 2015-12-22 IT ITUB2015A009726A patent/ITUB20159726A1/it unknown
• 2016
  • 2016-12-12 CN CN201680080146.9A patent/CN108603469B/zh not_active Expired - Fee Related
  • 2016-12-12 EP EP16815567.9A patent/EP3394417A1/de not_active Withdrawn
  • 2016-12-12 WO PCT/EP2016/080587 patent/WO2017108470A1/en active Application Filing

Patent Citations (6)

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