US20020044873A1 - High pressure fuel pump - Google Patents
High pressure fuel pump Download PDFInfo
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- US20020044873A1 US20020044873A1 US10/015,676 US1567601A US2002044873A1 US 20020044873 A1 US20020044873 A1 US 20020044873A1 US 1567601 A US1567601 A US 1567601A US 2002044873 A1 US2002044873 A1 US 2002044873A1
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- Prior art keywords
- swash plate
- plungers
- cylinders
- pump
- fuel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/122—Details or component parts, e.g. valves, sealings or lubrication means
- F04B1/124—Pistons
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
- F04B1/14—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
- F04B1/141—Details or component parts
- F04B1/143—Cylinders
Definitions
- the present invention relates to a fuel pump for fuel supply of an internal combustion engine and, more particularly, to a high pressure fuel pump used for a fuel injection system of a so-called direct fuel injection type internal combustion engine, which system injects directly fuel from a fuel injection valve mounted on a combustion chamber into the combustion chamber.
- a conventional high pressure fuel pump disclosed in JP A 9-250447 is constructed so as to circulate fuel also to a sliding portion of a driving mechanism part, and the driving mechanism part, that is, the sliding portion is lubricated with fuel.
- the former conventional pump has a problem that the pump is large-sized because of use of the metal bellows and it is difficult to make the pump size small because it is necessary to provide a seal portion on a bellows mounting portion.
- An object of the present invention is to provide an axial plunger pump in which any bellows is unnecessary and lubrication of a sliding portion of a driving mechanism part is sufficient.
- Another object of the present invention is to enable a roll bearing to be used in the driving mechanism part.
- an axial plunger pump is constructed so as to comprise a shaft having a swash plate effecting swing motion and transmitting driving force from the outside, plungers each reciprocating by the swing motion of the swash plate, a cylinder block having cylinders formed so as to open on the side of the swash plate and inserting therein the plungers and having passages for supplying fuel to the cylinders, a body combined with the cylinder block to enclose the swash plate, and sealing members arranged between the plungers and the cylinders on the swash plate side of the passages formed in the cylinder block for sealing gaps between the plungers and the cylinders, respectively.
- Another invention is a high pressure fuel pump which comprises a shaft having an swash plate effecting swing motion, and transmitting driving force from the outside, a plurality of plungers each reciprocating by the swing motion of the swash plate a cylinder block having cylinders formed so as to open on the side of the swash plate and inserting therein the plungers, the cylinder block having passages for supplying fuel to the cylinders, a body combined with the cylinder block to enclose the swash plate, a radial bearing supporting the shaft mounted on the body and a bearing arranged on the back of the swash plate for supporting an axial load applied on the swash plate, which bearing is a thrust roll bearing having rolls or balls larger in rolling pitch diameter than the radial bearing.
- Still another invention is a plunger for a high pressure fuel pump, which plunger has a radial hole traversing the central axis of the plunger, a groove formed on the periphery so as to overlap with the radial hole and having a prescribed axial length, and an end portion to which an axial hole communicating with the radial hole is opened and the other end portion is formed spherical.
- FIG. 1 is a sectional view of a high pressure fuel pump of a first embodiment of the present invention:
- FIG. 2 is a partially sectional view of a construction of passage in a rear body of the first embodiment
- FIGS. 3 a and 3 b each are a sectional view of a plunger and a surrounding portion thereof for explaining strokes;
- FIG. 4 is a sectional view of a shaft seal of a first embodiment
- FIG. 5 is a sectional view of a shaft seal of a second embodiment
- FIG. 6 is a sectional view of a shaft seal of a third embodiment.
- FIG. 7 is a sectional view of a high pressure fuel pump of a second embodiment of the present invention.
- FIGS. 1 and 2 A high pressure fuel pump of a first embodiment of the present invention is shown in FIGS. 1 and 2.
- a coupling 2 for transmitting drive force transmitted from a cam shaft of an engine to the pump has a shaft 5 connected by a pin 4 fitted to the coupling 2 .
- the shaft 5 has thereon a swash plate 12 which radially expands and which is formed in oblique flat plane at its end.
- the swash plate 12 is in contact with slippers 13 at the oblique flat plane and the slippers 13 each are formed substantially flat so that the slippers 13 can smoothly slide on the swash plate 12 rotating together with the shaft 5 .
- the slippers 13 each are formed in spherical shape on the other side, and swinging motion of the swash plate 12 imparts reciprocating motion to a plurality of plungers 14 each sliding in a cylinder bore 17 of a cylinder block 16 .
- the plurality of cylinder bores 17 and plungers 14 form a plurality of pump chambers 42 .
- An intake space 25 communicating with each plunger 14 is provided at the center of the cylinder block 16 so as to supply fuel to the pump chambers 42 .
- fuel piping is provided out of the pump, and the fuel is led to the intake space 25 through an intake passage 35 formed in a rear body 34 and an intake chamber 26 formed at the center of the rear body 34 and connected to the intake space 25 .
- an intake valve 18 (a check valve) is disposed, and the intake valve 18 is formed of a ball 22 , a spring 21 and a stopper 23 supporting the spring 21 .
- a plunger spring 24 is inserted for the purpose of causing the plunger 14 to follow the slipper 13 and the swash plate 12 .
- the stopper 23 is also used for supporting spring force of the plunger spring 24 .
- a communication passage A 50 to the plunger intake valve 18 is formed as an oblique passage which is inclined against an axial direction and led from the intake space 25 to the cylinder side.
- An intake groove 30 is formed in the outer periphery of the plunger 14 so that even if the plunger reciprocates, the communication passage A 50 and the intake valve 18 are always communicated, that is, they are communicated over the full stroke of the plunger 14 .
- the groove of width larger than the stroke of the plunger is formed. Since it is simple in construction because of groove formation without use of any other devices, it serves for making the construction small in size.
- FIG. 3 shows an enlarged view of the plunger 14 for explanation of strokes.
- a discharge stroke a stroke in which the space of the pump chamber 42 decreases
- a discharge valve 20 constructed of a ball 22 and a spring 21 as well as the intake valve 18 formed in the cylinder block 16 is opened, and the fuel supplied to the pump chamber 42 formed by the cylinder and the plunger 14 during the above-mentioned intake stroke is discharged from the pump chamber 42 .
- the intake chamber 26 and discharge chamber 28 are separated by an O-ring 32 , the intake chamber 26 is provided on the central side more than the discharge chamber 28 , whereby a passage construction in the pump itself is made compact.
- the pressure in the discharge chamber 28 of the rear body 34 can be controlled to an optimum pressure by a pressure regulator 36 provided on the discharge side.
- the purpose of controlling the discharge pressure is for controlling the pressure applied to an injector (not shown) disposed downstream of the discharge side.
- Excess high pressure side fuel supplied from the high pressure chamber of the rear body 34 to the pressure regulator 36 is returned to the intake chamber 26 through a ball valve 48 provided in the pressure regulator 36 and a communication passage B 52 provided in the rear body 34 .
- the intake passage 35 , intake chamber 26 , intake space 25 and communication passage A 50 form passages for supplying fuel from a fuel source to each cylinder.
- the fuel pressure in the pump chamber 42 also changes from an intake pressure (in general, 0.2 MPa to 0.5 MPa) to pressure in the high pressure chamber (in general, 3 MPa to 20 MPa).
- a load generated by the fuel pressure in the pump chamber 42 is transmitted to the swash plate 12 of the shaft 5 through the slippers 13 .
- the load to the slippers 13 is transmitted from each plunger 14 and transmitted to the swash plate 12 .
- the resultant force of forces of the plurality of plungers 14 is applied to the shaft 5 .
- the resultant force acts as; axial force and radial load according to the inclination angle of the swash plate 12 .
- the radial bearing 6 and the thrust bearing 8 are fitted to the shaft 5 , and the loads are supported by the body 10 .
- Portions (the slippers 13 /the swash plate 12 and the bearing portions) supporting those loads are portions at which a relative speed due to rotation exists and loads are supported. By lubricating those portions, wear due to sliding can be decreased. It, therefore, is necessary to provide a construction for storage of oil in the swash plate chamber 44 formed between the body 10 and cylinder block 16 .
- a shaft seal 38 sealing fuel and oil when the plungers 14 reciprocate is provided on the slipper side of the intake groove 30 of the plunger 14 .
- the shaft seal 38 is for sealing a gap between the plunger 14 and the cylinder bore 17 and it is a boundary between fuel and oil.
- one shaft seal 38 is provided on the plunger 14 , however, the same effect can be attained even by providing it on the cylinder side and also it can be attained by providing a plurality of shaft seals.
- the shaft seal 38 of the plunger 14 becomes a resistance against reciprocation of the plunger 14 .
- the plunger spring 24 is provided, and it is necessary to lower the resistance at the portion of the shaft seal 38 .
- FIG. 4 shows seals of such a shape.
- Material of PTFE which is small in friction coefficient is used on the sliding surface side.
- FIG. 5 shows an X-shaped rubber seal which is reduced in sliding surface area.
- fluorine-contained rubber is used for the rubber material.
- FIG. 6 shows a rip seal of another embodiment of the seal member.
- a counterbore is formed in the cylinder bore 17 .
- the counterbore is a bore of larger diameter than the diameter of the cylinder bore 17 , and in order that fuel can be sufficiently introduced into the plunger 14 , the counterbore is formed to the depth of such extent as the counterbore can communicate with an introduction hole 60 even when the pump chamber 42 becomes sufficiently small. If fuel can be sufficiently introduced into the plunger 14 in this manner even when the displacement of the pump chamber 42 is reduced to a sufficiently small one, the communication passage A 50 is unnecessary to be oblique.
- the shaft seal 38 inside the reciprocating portion of the plunger 14 diffuses the fuel adhered to the surface of the plunger 14 into oil in a thin layer.
- Oil in the swash plate chamber 44 is inserted when the pump is assembled, and it is necessary to introduce, into the pump, oil on the side of engine, used on the cam shaft side during engine driving operation after it is mounted on the engine.
- any shaft seal is not provided so that the oil can be introduced from the radial bearing portion 6 of the shaft 5 . Therefore, if oil is introduced from the radial bearing portion 6 to an upper portion, oil leaks from a gap between the shaft 5 and the radial bearing 6 to the engine side.
- the oil is stored to a level higher than the radial bearing portion 6 .
- a ball bearing is used for the radial bearing 6
- a roll bearing also can be used therefor. Since the radial bearing 6 is small in load and used in oil, a slide bearing also can be used therefor.
- FIG. 7 show a second embodiment in which an oil introduction passage 46 for positively introducing oil on the engine into the swash plate chamber 44 is provided.
- the oil introduction passage 46 is provided on the body 100 .
- the pressure on the oil introduction side is made higher than the oil pressure in the swash plate chamber 44 .
- the pressure in the swash plate chamber 44 is made smaller than the fuel intake pressure as shown in the first embodiment.
- the engine oil introduce is returned to the engine side from the radial bearing 6 portion at the center of shaft 5 . Foreign matters contained in the oil introduced from the engine side are scattered toward the body inner side by centrifugal force due to rotation of the shaft 5 , so that portions of the thrust bearing 8 and radial bearing fitted to the shaft 5 can be lubricated with clean oil.
- the pump body can be made small in size. Further, since the swash plate portion can be lubricated with lubrication oil, roll bearings can be used for bearings, therefore, frictional resistance at a low speed can be reduced, so that small driving torque is sufficient for driving.
Abstract
An axial plunger pump according to the present invention is constructed so as to comprise a shaft having a swash plate effecting swing motion and transmitting driving force from the outside, plungers each reciprocating by the swing motion of the swash plate, a cylinder block having cylinders formed so as to open on the side of the swash plate and inserting therein the plungers and having passages for supplying fuel to the cylinders, a body combined with the cylinder block to enclose the swash plate, and sealing members arranged between the plungers and the cylinders on the swash plate side of the passages formed in the cylinder block for sealing gaps between the plungers and the cylinders, respectively.
Description
- The present invention relates to a fuel pump for fuel supply of an internal combustion engine and, more particularly, to a high pressure fuel pump used for a fuel injection system of a so-called direct fuel injection type internal combustion engine, which system injects directly fuel from a fuel injection valve mounted on a combustion chamber into the combustion chamber.
- For an internal engine in which fuel is directly injected into the combustion chamber, it is necessary to have a high pressure pump for raising the pressure of fuel to be supplied to an fuel injection valve to a pressure of 2 MPa or more.
- As such a high pressure pump, there has been known a conventional axial plunger pump which is disclosed in JP A 9-236080. Such a conventional axial plunger pump is constructed so as to partition a driving mechanism part lubricated with oil and a pump chamber compressing and discharging fuel by a metal bellows.
- Further, a conventional high pressure fuel pump disclosed in JP A 9-250447 is constructed so as to circulate fuel also to a sliding portion of a driving mechanism part, and the driving mechanism part, that is, the sliding portion is lubricated with fuel.
- The above-mentioned conventional high pressure fuel pumps have the following problems or disadvantages.
- 1. The former conventional pump has a problem that the pump is large-sized because of use of the metal bellows and it is difficult to make the pump size small because it is necessary to provide a seal portion on a bellows mounting portion.
- 2. In the latter conventional pump, it is not necessary to provide any bellows, however, lubrication is insufficient because the sliding portion of the driving mechanism part is lubricated with fuel of low viscosity.
- An object of the present invention is to provide an axial plunger pump in which any bellows is unnecessary and lubrication of a sliding portion of a driving mechanism part is sufficient.
- Another object of the present invention is to enable a roll bearing to be used in the driving mechanism part.
- In order to solve the above problems, an axial plunger pump according to the present invention is constructed so as to comprise a shaft having a swash plate effecting swing motion and transmitting driving force from the outside, plungers each reciprocating by the swing motion of the swash plate, a cylinder block having cylinders formed so as to open on the side of the swash plate and inserting therein the plungers and having passages for supplying fuel to the cylinders, a body combined with the cylinder block to enclose the swash plate, and sealing members arranged between the plungers and the cylinders on the swash plate side of the passages formed in the cylinder block for sealing gaps between the plungers and the cylinders, respectively.
- Another invention is a high pressure fuel pump which comprises a shaft having an swash plate effecting swing motion, and transmitting driving force from the outside, a plurality of plungers each reciprocating by the swing motion of the swash plate a cylinder block having cylinders formed so as to open on the side of the swash plate and inserting therein the plungers, the cylinder block having passages for supplying fuel to the cylinders, a body combined with the cylinder block to enclose the swash plate, a radial bearing supporting the shaft mounted on the body and a bearing arranged on the back of the swash plate for supporting an axial load applied on the swash plate, which bearing is a thrust roll bearing having rolls or balls larger in rolling pitch diameter than the radial bearing.
- Still another invention is a plunger for a high pressure fuel pump, which plunger has a radial hole traversing the central axis of the plunger, a groove formed on the periphery so as to overlap with the radial hole and having a prescribed axial length, and an end portion to which an axial hole communicating with the radial hole is opened and the other end portion is formed spherical.
- FIG. 1 is a sectional view of a high pressure fuel pump of a first embodiment of the present invention:
- FIG. 2 is a partially sectional view of a construction of passage in a rear body of the first embodiment;
- FIGS. 3a and 3 b each are a sectional view of a plunger and a surrounding portion thereof for explaining strokes;
- FIG. 4 is a sectional view of a shaft seal of a first embodiment;
- FIG. 5 is a sectional view of a shaft seal of a second embodiment;
- FIG. 6 is a sectional view of a shaft seal of a third embodiment; and
- FIG. 7 is a sectional view of a high pressure fuel pump of a second embodiment of the present invention.
- A high pressure fuel pump of a first embodiment of the present invention is shown in FIGS. 1 and 2.
- In FIG. 1, a
coupling 2 for transmitting drive force transmitted from a cam shaft of an engine to the pump has ashaft 5 connected by apin 4 fitted to thecoupling 2. Theshaft 5 has thereon aswash plate 12 which radially expands and which is formed in oblique flat plane at its end. Theswash plate 12 is in contact withslippers 13 at the oblique flat plane and theslippers 13 each are formed substantially flat so that theslippers 13 can smoothly slide on theswash plate 12 rotating together with theshaft 5. Theslippers 13 each are formed in spherical shape on the other side, and swinging motion of theswash plate 12 imparts reciprocating motion to a plurality ofplungers 14 each sliding in acylinder bore 17 of acylinder block 16. - With the pump of the above construction, intake and discharge of fuel is carried out as follows.
- The plurality of cylinder bores17 and plungers 14 form a plurality of
pump chambers 42. Anintake space 25 communicating with eachplunger 14 is provided at the center of thecylinder block 16 so as to supply fuel to thepump chambers 42. In order to introduce fuel into theintake space 25, fuel piping is provided out of the pump, and the fuel is led to theintake space 25 through an intake passage 35 formed in arear body 34 and anintake chamber 26 formed at the center of therear body 34 and connected to theintake space 25. - In each
plunger 14, an intake valve 18 (a check valve) is disposed, and theintake valve 18 is formed of aball 22, aspring 21 and astopper 23 supporting thespring 21. Aplunger spring 24 is inserted for the purpose of causing theplunger 14 to follow theslipper 13 and theswash plate 12. Thestopper 23 is also used for supporting spring force of theplunger spring 24. - A
communication passage A 50 to theplunger intake valve 18 is formed as an oblique passage which is inclined against an axial direction and led from theintake space 25 to the cylinder side. Anintake groove 30 is formed in the outer periphery of theplunger 14 so that even if the plunger reciprocates, thecommunication passage A 50 and theintake valve 18 are always communicated, that is, they are communicated over the full stroke of theplunger 14. Concretely, the groove of width larger than the stroke of the plunger is formed. Since it is simple in construction because of groove formation without use of any other devices, it serves for making the construction small in size. - FIG. 3 shows an enlarged view of the
plunger 14 for explanation of strokes. When the above-mentioned intake stroke is turned to a discharge stroke (a stroke in which the space of thepump chamber 42 decreases) and when the pressure in adischarge chamber 28 formed in therear body 34 reaches to a prescribed pressure, adischarge valve 20 constructed of aball 22 and aspring 21 as well as theintake valve 18 formed in thecylinder block 16 is opened, and the fuel supplied to thepump chamber 42 formed by the cylinder and theplunger 14 during the above-mentioned intake stroke is discharged from thepump chamber 42. Here, theintake chamber 26 anddischarge chamber 28 are separated by an O-ring 32, theintake chamber 26 is provided on the central side more than thedischarge chamber 28, whereby a passage construction in the pump itself is made compact. - The pressure in the
discharge chamber 28 of therear body 34 can be controlled to an optimum pressure by apressure regulator 36 provided on the discharge side. The purpose of controlling the discharge pressure is for controlling the pressure applied to an injector (not shown) disposed downstream of the discharge side. Excess high pressure side fuel supplied from the high pressure chamber of therear body 34 to thepressure regulator 36 is returned to theintake chamber 26 through aball valve 48 provided in thepressure regulator 36 and acommunication passage B 52 provided in therear body 34. The intake passage 35,intake chamber 26,intake space 25 andcommunication passage A 50 form passages for supplying fuel from a fuel source to each cylinder. - In this manner, the fuel pressure in the
pump chamber 42 also changes from an intake pressure (in general, 0.2 MPa to 0.5 MPa) to pressure in the high pressure chamber (in general, 3 MPa to 20 MPa). A load generated by the fuel pressure in thepump chamber 42 is transmitted to theswash plate 12 of theshaft 5 through theslippers 13. The load to theslippers 13 is transmitted from eachplunger 14 and transmitted to theswash plate 12. On the other hand, the resultant force of forces of the plurality ofplungers 14 is applied to theshaft 5. The resultant force acts as; axial force and radial load according to the inclination angle of theswash plate 12. In order to support those loads and achieve smooth rotation, the radial bearing 6 and the thrust bearing 8 are fitted to theshaft 5, and the loads are supported by thebody 10. - Portions (the
slippers 13/theswash plate 12 and the bearing portions) supporting those loads are portions at which a relative speed due to rotation exists and loads are supported. By lubricating those portions, wear due to sliding can be decreased. It, therefore, is necessary to provide a construction for storage of oil in theswash plate chamber 44 formed between thebody 10 andcylinder block 16. - In this embodiment, therefore, a shaft seal38 sealing fuel and oil when the
plungers 14 reciprocate is provided on the slipper side of theintake groove 30 of theplunger 14. Theshaft seal 38 is for sealing a gap between theplunger 14 and the cylinder bore 17 and it is a boundary between fuel and oil. By constructing in this manner, intake pressure of low pressure on the side of theintake groove 30 is always applied to theshaft seal 38. The intake pressure does not largely change as the pressure in thepump chamber 42, a constant pressure is applied on theshaft seal 38. This construction raises the sealing performance and reliability of theshaft seal 38. - In this embodiment, one
shaft seal 38 is provided on theplunger 14, however, the same effect can be attained even by providing it on the cylinder side and also it can be attained by providing a plurality of shaft seals. - On the other hand, the
shaft seal 38 of theplunger 14 becomes a resistance against reciprocation of theplunger 14. In the pump construction of the present embodiment, in order to raise the property that theplunger 14 follows theslippers 13 andswash plate 12, theplunger spring 24 is provided, and it is necessary to lower the resistance at the portion of theshaft seal 38. In order to decrease the slide friction resistance due to the seal at the portion of theshaft seal 38, it is important to elect material of low friction coefficient and to elect a suitable shape. - FIG. 4 shows seals of such a shape. Material of PTFE which is small in friction coefficient is used on the sliding surface side.
- FIG. 5 shows an X-shaped rubber seal which is reduced in sliding surface area. In view of being high in circumference temperature in use of the pump, fluorine-contained rubber is used for the rubber material.
- FIG. 6 shows a rip seal of another embodiment of the seal member. Further, instead of formation of the
intake groove 30, a counterbore is formed in the cylinder bore 17. The counterbore is a bore of larger diameter than the diameter of the cylinder bore 17, and in order that fuel can be sufficiently introduced into theplunger 14, the counterbore is formed to the depth of such extent as the counterbore can communicate with anintroduction hole 60 even when thepump chamber 42 becomes sufficiently small. If fuel can be sufficiently introduced into theplunger 14 in this manner even when the displacement of thepump chamber 42 is reduced to a sufficiently small one, thecommunication passage A 50 is unnecessary to be oblique. - In order to lubricate the driving mechanism portion with fuel as in a conventional manner, it is necessary for all the bearings to be slide bearings. Therefore, excess drive torque due to the slide friction resistance becomes necessary (the viscosity coefficient of fuel is low, particularly, since oil film formation is difficult at a low speed operation, frictional resistance becomes extremely large).
- However, as mentioned above, by a construction separating oil and fuel within the reciprocating portion, it is possible to lubricate the inside of the
swash plate chamber 44 with oil. Further, in the present embodiment, leakage of oil onto the fuel side is prevented by making the pressure in theswash plate chamber 44 less than the intake fuel pressure, whereby the oil is prevented from being decreased in amount. - By the construction in which oil is always stored in the
swash plate chamber 44 in this manner, it becomes possible to use roll bearings for the bearings supporting the above-mentioned loads. Particularly, it is possible to use the roll bearings for the thrust bearings, whereby reduction of the drive torque and the reliability of the siding portion can be improved. - However, the
shaft seal 38 inside the reciprocating portion of theplunger 14 diffuses the fuel adhered to the surface of theplunger 14 into oil in a thin layer. Oil in theswash plate chamber 44 is inserted when the pump is assembled, and it is necessary to introduce, into the pump, oil on the side of engine, used on the cam shaft side during engine driving operation after it is mounted on the engine. In order to introduce engine oil into the pump, in the present embodiment, any shaft seal is not provided so that the oil can be introduced from theradial bearing portion 6 of theshaft 5. Therefore, if oil is introduced from theradial bearing portion 6 to an upper portion, oil leaks from a gap between theshaft 5 and theradial bearing 6 to the engine side. If an amount of oil introduced therein is more than the leaked oil, the oil is stored to a level higher than theradial bearing portion 6. Further, in this embodiment, a ball bearing is used for theradial bearing 6, however, a roll bearing also can be used therefor. Since theradial bearing 6 is small in load and used in oil, a slide bearing also can be used therefor. - Even if an amount of oil stored is a level lower than the
radial bearing 6, in order that rotating members are always submerged in the oil, a pitch circle of rolls (or rolling pitch circle of balls) of thethrust bearing 8 and the outer diameter of theswash plate 12 are made larger thanradial bearing 6. Theslippers 13 contacting with theswash plate 12 and converting swinging motion to reciprocation also is lubricated with oil adhered to theswash plate 12, whereby the swash plate portion is able to be lubricated with oil. - FIG. 7 show a second embodiment in which an
oil introduction passage 46 for positively introducing oil on the engine into theswash plate chamber 44 is provided. Theoil introduction passage 46 is provided on thebody 100. In this case, the pressure on the oil introduction side is made higher than the oil pressure in theswash plate chamber 44. Here, the pressure in theswash plate chamber 44 is made smaller than the fuel intake pressure as shown in the first embodiment. Further, the engine oil introduce is returned to the engine side from theradial bearing 6 portion at the center ofshaft 5. Foreign matters contained in the oil introduced from the engine side are scattered toward the body inner side by centrifugal force due to rotation of theshaft 5, so that portions of thethrust bearing 8 and radial bearing fitted to theshaft 5 can be lubricated with clean oil. - Since a member such as bellows and a seal member provided at the mounting portion thereof in order to separate an oil circulation portion and a fuel circulation portion become unnecessary, the pump body can be made small in size. Further, since the swash plate portion can be lubricated with lubrication oil, roll bearings can be used for bearings, therefore, frictional resistance at a low speed can be reduced, so that small driving torque is sufficient for driving.
Claims (7)
1. A high pressure fuel pump comprising:
a shaft having an swash plate effecting swing motion, and transmitting driving force from the outside;
plungers each reciprocating by the swing motion of said swash plate;
a cylinder block having cylinders formed therein so as to open on the side of said swash plate and inserting therein said plungers, said cylinder block having passages for supplying fuel to said cylinders;
a body combined with said cylinder block to enclose said swash plate; and
sealing members arranged between said plungers and said cylinders for sealing gaps between said plungers and said cylinders, respectively, said sealing members being axially separated from said passages toward said swash plate.
2. A high pressure fuel pump according to claim 1 ,
wherein fuel is supplied to pump chambers formed by said plungers and said cylinders, respectively.
3. A high pressure fuel pump according to claim 1 , wherein said pump comprises:
pump chambers formed by said plungers and said cylinders;
passages arranged inside said plungers for communicating between said passages for supplying fuel to said cylinders and said pump chambers;
grooves arranged inside said plungers so that said passages arranged inside said plungers are always communicating with said passage for supplying fuel to said said cylinders; and
valves for partitioning said pump chambers and said passages arranged inside said plungers, said valves allowing communication between said pump chambers and said passages arranged inside said plungers when fuel is a first pressure or higher; and
wherein fuel is supplied to said pump chambers through said plungers.
4. A high pressure fuel pump according to claim 1 ,
wherein said pump comprises:
an oil chamber enclosed by said body for lubricating the swash plate side of said sealing members; and
a hole provided in said body for introducing oil on the engine side into said oil chamber.
5. A high pressure fuel pump comprising:
a shaft having an swash plate effecting swing motion, and transmitting driving force from the outside;
plungers each reciprocating by the swing motion of said swash plate;
a cylinder block having cylinders formed so as to open on the side of said swash plate and inserting therein said plungers, said cylinder block having passages for supplying fuel to said cylinders;
a body combined with said cylinder block to enclose said swash plate;
a radial bearing supporting said shaft mounted on said body and
a bearing arranged on the back of said swash plate for supporting an axial load applied on said swash plate, said bearing being a thrust roll bearing having rolls or balls larger in rolling pitch diameter than said radial bearing.
6. A high pressure fuel pump according to claim 5 ,
wherein a gap for inflow and/or outflow of oil is provided between said shaft and said radial bearing.
7. A plunger for a high pressure fuel pump, having:
a radial hole traversing the central axis of said plunger;
a groove formed on the periphery so as to overlap with said radial hole and having a prescribed axial length;
an end portion to which an axial hole communicating with said radial hole is opened; and
the other end portion formed spherical.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US10/015,676 US20020044873A1 (en) | 1998-10-08 | 2001-12-17 | High pressure fuel pump |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
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JP10-286756 | 1998-10-08 | ||
JP10286756A JP2000110710A (en) | 1998-10-08 | 1998-10-08 | High-pressure fuel pump |
US09/414,648 US6368071B1 (en) | 1998-10-08 | 1999-10-08 | High pressure fuel pump |
US10/015,676 US20020044873A1 (en) | 1998-10-08 | 2001-12-17 | High pressure fuel pump |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US09/414,648 Continuation US6368071B1 (en) | 1998-10-08 | 1999-10-08 | High pressure fuel pump |
Publications (1)
Publication Number | Publication Date |
---|---|
US20020044873A1 true US20020044873A1 (en) | 2002-04-18 |
Family
ID=17708646
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/414,648 Expired - Fee Related US6368071B1 (en) | 1998-10-08 | 1999-10-08 | High pressure fuel pump |
US10/015,676 Abandoned US20020044873A1 (en) | 1998-10-08 | 2001-12-17 | High pressure fuel pump |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/414,648 Expired - Fee Related US6368071B1 (en) | 1998-10-08 | 1999-10-08 | High pressure fuel pump |
Country Status (2)
Country | Link |
---|---|
US (2) | US6368071B1 (en) |
JP (1) | JP2000110710A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010117486A3 (en) * | 2009-03-31 | 2011-04-14 | General Electric Company | High pressure variable displacement piston pump |
CN106884713A (en) * | 2017-03-02 | 2017-06-23 | 四川大学 | End tooth wheel cam removable tooth frame output type internal combustion engine |
CN107044341A (en) * | 2017-02-24 | 2017-08-15 | 四川大学 | Two-phase balance end tooth wheel cam type internal combustion engine |
CN107044342A (en) * | 2017-03-06 | 2017-08-15 | 四川大学 | Two-phase balance cam removable tooth frame output type internal combustion engine |
CN107246319A (en) * | 2017-03-17 | 2017-10-13 | 四川大学 | Cam removable tooth frame end gear output type internal combustion engine |
CN108301998A (en) * | 2017-12-29 | 2018-07-20 | 浙江工业大学 | A kind of two-dimentional plunger pump of rolling wheel guide rails transmission |
CN112983703A (en) * | 2021-04-16 | 2021-06-18 | 山东交通职业学院 | Fuel oil filtering device for petroleum machinery |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000073657A1 (en) * | 1999-05-26 | 2000-12-07 | Luk Fahrzeug-Hydraulik Gmbh & Co. Kg | Compressor |
JP2001003839A (en) * | 1999-06-21 | 2001-01-09 | Hitachi Ltd | High pressure fuel pump |
IT201900024199A1 (en) * | 2019-12-17 | 2021-06-17 | Mixtron S R L | INCLINED PLATE AXIAL PISTON PUMP |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3455585A (en) * | 1965-12-01 | 1969-07-15 | Int Basic Economy Corp | Piston shoe construction |
US3663122A (en) * | 1970-11-25 | 1972-05-16 | Mcneil Corp | Axial plunger pump |
US4642032A (en) * | 1985-08-07 | 1987-02-10 | Teleflex Incorporated | Axial piston pump including ball piston |
JP2572034Y2 (en) * | 1992-02-10 | 1998-05-20 | 株式会社ユニシアジェックス | Pump structure |
JPH061782U (en) * | 1992-06-08 | 1994-01-14 | 株式会社豊田自動織機製作所 | Variable capacity swash plate compressor |
US5466130A (en) * | 1994-07-26 | 1995-11-14 | Kobelt; Jacob | Helm pump |
US5647266A (en) * | 1994-10-03 | 1997-07-15 | Dynex/Rivett, Inc. | Hold-down mechanism for hydraulic pump |
US5601345A (en) * | 1994-12-16 | 1997-02-11 | Kelsey-Hayes Company | Stationary seal ABS pump |
JPH09236080A (en) | 1996-02-29 | 1997-09-09 | Unisia Jecs Corp | Axial plunger pump |
JPH09250447A (en) | 1996-03-15 | 1997-09-22 | Hitachi Ltd | Fluid supply pump and fuel supply pump |
-
1998
- 1998-10-08 JP JP10286756A patent/JP2000110710A/en active Pending
-
1999
- 1999-10-08 US US09/414,648 patent/US6368071B1/en not_active Expired - Fee Related
-
2001
- 2001-12-17 US US10/015,676 patent/US20020044873A1/en not_active Abandoned
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010117486A3 (en) * | 2009-03-31 | 2011-04-14 | General Electric Company | High pressure variable displacement piston pump |
CN107044341A (en) * | 2017-02-24 | 2017-08-15 | 四川大学 | Two-phase balance end tooth wheel cam type internal combustion engine |
CN106884713A (en) * | 2017-03-02 | 2017-06-23 | 四川大学 | End tooth wheel cam removable tooth frame output type internal combustion engine |
CN107044342A (en) * | 2017-03-06 | 2017-08-15 | 四川大学 | Two-phase balance cam removable tooth frame output type internal combustion engine |
CN107246319A (en) * | 2017-03-17 | 2017-10-13 | 四川大学 | Cam removable tooth frame end gear output type internal combustion engine |
CN108301998A (en) * | 2017-12-29 | 2018-07-20 | 浙江工业大学 | A kind of two-dimentional plunger pump of rolling wheel guide rails transmission |
CN112983703A (en) * | 2021-04-16 | 2021-06-18 | 山东交通职业学院 | Fuel oil filtering device for petroleum machinery |
Also Published As
Publication number | Publication date |
---|---|
US6368071B1 (en) | 2002-04-09 |
JP2000110710A (en) | 2000-04-18 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |