CN110691904A

CN110691904A - High-pressure fuel pump assembly for internal combustion piston engine

Info

Publication number: CN110691904A
Application number: CN201780091352.4A
Authority: CN
Inventors: O·拉克索; A·沃约齐; K·埃克隆; D·C·杰伊
Original assignee: Vassiland Finland Co Ltd
Current assignee: Vassiland Finland Co Ltd; Wartsila Finland Oy
Priority date: 2017-03-29
Filing date: 2017-03-29
Publication date: 2020-01-14
Anticipated expiration: 2037-03-29
Also published as: CN110691904B; KR20190124810A; WO2018178501A1; EP3601777A1; KR102239680B1; EP3601777B1

Abstract

The invention relates to a high pressure fuel pump assembly (100) comprising a drive shaft lubrication system (114), a pump unit lubrication system (116) and at least one inlet (115) for pressurized lubricant and several piston pump units (10) driven by a drive shaft (110) of the pump assembly (100), wherein the pump assembly (100) is provided with a first collector conduit (120) configured to receive lubricant from the pump unit lubrication system (116) and a second collector conduit (122) configured to receive leaked fuel from the piston pump units and a third collector conduit configured to receive fuel mist from the piston pump units.

Description

High-pressure fuel pump assembly for internal combustion piston engine

Technical Field

The present invention relates to a high-pressure fuel pump assembly for a piston engine of an internal combustion engine according to the preamble of claim 1.

Background

Internal combustion piston engines need to be provided with one or more fuel pumps. In particular, the injection of fuel into the combustion chambers of an engine in a so-called common rail system requires the ability to be able to pump fuel into high pressures even exceeding 250 MPa. Since the pump is usually lubricated by the lubricating medium of the engine, the presence of both the fuel and the lubricating medium in the pump may require special attention, in particular in connection with preventing or minimizing mixing of the fuel and the lubricant in the pump.

Document EP 0976926B1 discloses an integrated pump and tappet unit for supplying fuel to an internal combustion engine, such as a large diesel engine, comprising: a body portion that surrounds a tappet member, the axial movement of which is controlled by a cam surface provided on a camshaft or the like; and a piston member operatively connected to the tappet member and arranged to pump fuel at high pressure from a fuel chamber provided within the body portion. The main body portion is a single member housing both the tappet member and the fuel chamber, and the tappet member and the piston member are connected to each other by means of a tappet arm, which is sealed to a flange member fixed to the main body portion, such that fuel from the fuel chamber is prevented from coming into contact with the tappet member.

Document DE 102015002304a1 discloses a high-pressure fuel pump. This document does not mention that fuel may leak into the lubricating medium, but shows the lubrication system of the pump. The pump includes: a pump housing having an interior space; a pump plunger having a guide surface that is guided into an interior space on the pump housing, wherein the interior space and the pump plunger bound a spring chamber of the high-pressure fuel pump; a lubrication line opening into the interior space against the guide surface of the plunger; a vent line by means of which lubricant can be discharged from the spring chamber.

Document DE 102008042067a1 discloses a pump having a drive shaft provided with an eccentric cam and a piston accommodated in a cylinder. This document discloses a circular diaphragm seal for separating the fuel system and the lubrication system from each other.

Document DE 102006059333a1 discloses a fuel pump comprising at least one oil wiper element integrated in the pump piston for removing leakage fuel collected from the cylinder wall between the pump cylinder and the pump piston. The oil wiper element is an oil wiper ring which removes leakage fuel that has accumulated on the pump cylinder wall and guides it into at least one leakage groove.

US 7308849 defines a working chamber and is driven at least indirectly by a reciprocating drive shaft, against the force of a return spring. The pump piston is supported at least indirectly on the drive shaft via a sleeve like a tappet, and the return spring engages at least with the pump piston. The support element in the tappet supports the pump piston against the drive shaft and at least indirectly against the drive shaft. The return spring engages the pump piston and the tappet via a spring plate. The spring plate is elastically deformable in the direction of movement of the pump piston, so that as a result of its elastic deformation, deviations of the position of its contact surfaces on the pump piston and on the tappet are compensated.

WO 2011160908a1 discloses a pump comprising at least one pump element with a pump piston which is driven at least indirectly by a drive shaft in a stroke movement. The plunger with the plunger body is arranged between the drive shaft and the pump piston and is guided in the receiving device movably in the stroke movement direction of the pump piston and is supported on the drive shaft by means of a support element. Lubricant is supplied to the receiving means via a supply line and lubricant is conducted out of the receiving means into the plunger body via a discharge line to the support element. An annular gap filter is provided between the plunger body and the receiving means, which annular gap filter is arranged between a supply line for supplying lubricant to the receiving means and a discharge line for discharging lubricant into the plunger body.

It is an object of the present invention to provide a high-pressure fuel pump assembly, the performance of which is greatly improved compared to prior art solutions.

Disclosure of Invention

The objects of the invention can be met substantially as disclosed in the independent claims and in the other claims, which describe more details of different embodiments of the invention.

A high pressure fuel pump assembly for an internal combustion piston engine according to an embodiment of the present invention comprises a drive shaft lubrication system, a pump unit lubrication system and at least one inlet for pressurized lubricant and several piston pump units driven by the drive shaft of the pump assembly. The pump assembly is provided with a first collector conduit configured to receive lubricant from the pump unit lubrication system and a second collector conduit configured to receive leaked fuel from the piston pump unit and a third collector conduit configured to receive fuel mist from the piston pump unit.

According to an embodiment of the invention, the first, second and third collector conduits are arranged in a fluid collector block which is releasably attached to the pump unit.

According to an embodiment of the invention, the first collector conduit is configured to receive lubricant from the drive shaft lubrication system and from the pump unit lubrication system.

According to an embodiment of the invention, the first collector duct, the second collector duct and the third collector duct are arranged horizontally in a lower position with respect to the pump unit, so that there is a substantially continuously inclined flow passage arranged from the pump unit to the ducts.

According to an embodiment of the invention, the first collector duct is arranged vertically below an outlet of the drive shaft lubrication system, the second collector duct is arranged vertically below an outlet of the piston pump unit, and the third collector duct is arranged vertically below an outlet of the piston pump unit.

According to an embodiment of the invention, the high-pressure fuel pump assembly comprises several piston pump units in line.

According to an embodiment of the invention, the high pressure fuel pump assembly comprises several piston pump units in two sets of pistons in a v-shaped configuration, and the fluid collector block is arranged between the two sets of pistons.

According to an embodiment of the invention, the fluid collector block is provided with several fluid interfaces and the piston pump unit is provided with corresponding fluid interfaces, wherein the fluid interfaces are fitted to each other such that when the fluid interfaces are coupled, a sealed fluid communication is formed between the fluid collector block and the piston pump unit.

According to an embodiment of the invention, the fluid interfaces of the piston pump units are directed to open into a direction between the groups of the pump units, and the fluid collector block is provided with several fluid interfaces, which are in two rows, such that the several fluid interfaces are simultaneously connected to respective fluid interfaces of the groups of the piston pumps.

According to an embodiment of the invention, the fluid collector block is arranged below the drive shaft.

The invention is suitable for use as a high pressure pump unit in a common rail fuel system, i.e. it may be referred to as a high pressure common rail pump assembly.

The exemplary embodiments of the invention set forth in this patent application are not to be construed as limiting the applicability of the appended claims. The verb "to comprise" is used in this patent application as an open limitation, not excluding the presence of also unrecited features. The features set forth in the dependent claims can be freely combined with one another, unless explicitly stated otherwise. The novel features believed characteristic of the invention are set forth with particularity in the appended claims.

Drawings

The invention will be described below with reference to the appended schematic exemplary drawings, in which:

fig. 1 illustrates a fuel pump unit according to an embodiment of the present invention, and

FIG. 2 illustrates a fuel pump assembly according to an embodiment of the present invention.

Detailed Description

Fig. 1 schematically depicts a fuel pump 10 configured for supplying fuel to an internal combustion piston engine. More specifically, the pump is a high pressure pump configured to deliver fuel at a pressure in excess of 200 MPa. The pump is intended to be used in connection with a high-pressure fuel pump assembly as shown in fig. 2, whereby the position of the pump is present at the position of the pump assembly. The pump 10 is provided with a supply rail 12 and a high pressure rail 14, both the supply rail 12 and the high pressure rail 14 being connected with a first pump chamber 16 arranged on a body 18 of the pump 10. The body 18 including the pump chamber 16 may also be referred to as the barrel of the pump 10. Supply rail 12 is connected to a fuel source for the engine. The high pressure rail 14 contains pressurized fuel for injection into the combustion chambers of the engine. Supply rail 12 is connected to pump chamber 16 via an intake conduit 20. The high pressure rail 12 is connected to the pump chamber 16 via an outlet conduit 22. The intake conduit 20 is provided with a one-way valve 24, the one-way valve 24 being configured to allow fuel to flow only from the supply rail 12 to the pumping chamber 16. Accordingly, outlet conduit 22 is provided with a one-way valve 26, with one-way valve 26 being configured to allow fuel to flow only from pumping chamber 16 to high pressure rail 14. In the embodiment shown in fig. 1, the supply rail 12 and the high pressure rail 14 are integrated in the main body 18, but it is contemplated that the rails may be external to the main body 18.

The pump 10 is further provided with a piston member 28, the piston member 28 being arranged in a cylindrical space 30 arranged in the body 18. The cylindrical space 30 has a central axis 32, and the cylindrical space 30 is substantially rotationally symmetrical with respect to the central axis 32. Thus, the piston member 28 is also rotationally symmetric with respect to the central axis 32. The external form of the body may be designed as desired. The piston member 28 is disposed in the space in a reciprocally movable manner. The piston member 28 has a first end 28', the first end 28' forming a boundary of the cylindrical space 30 at the end of the cylindrical space 30 forming the first pumping chamber 16. The piston also has a second end 28 "opposite the first end 28'. The piston member 28 is configured to reciprocate and pump fuel in a space 30 provided for the piston member 28. In this way, the reciprocating piston member, together with the one-way valves 24, 26, provides the pumping effect of the fuel pump.

The cylindrical space 30 comprises a first space section 30' having a first diameter D1. The piston member 28 is at least partially located within the first space section 30'. In the first space section 30', the walls of this space section and the walls of the piston member 28 are arranged against each other, providing a first sealing gap 34 between these walls, which walls also guide the piston member 28 in the body 18. In addition, the wall of the first space section guides the piston member in the main body 18 while the piston member reciprocates in the space 30. The piston member 28 comprises a first portion 28', which first portion 28' is arranged in the first space section 30' and has substantially the same diameter as the first diameter, so that the desired guiding and sealing is provided.

At one end of the body 18, the cylindrical space 30 includes a second space section 30 "having a second diameter D2, the second diameter D2 being greater than the first diameter D1. The second spatial segment 30 "is on the same central axis as the first spatial segment 30'. The piston member 28 comprises a second portion 28 ", the second portion 28" being arranged in the second space section 30 "such that the desired guiding and sealing is provided. In the second space section 30 ", the walls of the second space section and the walls of the piston member 28 are arranged against each other, thereby providing a second sealing gap 35 between these walls, respectively. In addition, the wall of the second spatial section guides the second portion of the piston member in the body 18 while the piston member reciprocates in the space. The piston member 28 is advantageously an assembly of a plurality of components.

The body 18 of the pump 10 is arranged with a second pump chamber 16'. More specifically, second pump chamber 16 'is arranged in connection with second spatial section 30 ", such that second pump chamber 16' is configured to use the empty space of second spatial section 30" as a pump chamber. The piston member 28 is arranged to form a boundary of both the first pump chamber 16 and the second pump chamber 16'.

In the pump shown in fig. 1, a piston member 28 and first and second pump chambers 16, 16' are arranged such that the volumes of the first and second pump chambers change in the same manner, i.e. either increase or decrease, during movement of the piston member in one direction.

As mentioned before, in the first spatial section 30' the walls of the spatial section and the walls of the piston member 28 are arranged against each other, thereby providing a first sealing gap 34 between the walls. First seal gap 34 separates first pump chamber 16 from second pump chamber 16', and it takes the form of an annulus. Since the first pump chamber 16 operates as a high-pressure pump configured to deliver fuel at a pressure exceeding 200MPa, the fuel in the first pump chamber tends to flow into the first seal gap 34 and further flows through the seal gap 34. The first seal gap 34 between the pumping chambers 16, 16' is also provided with means for collecting fuel material flowing from the first pumping chamber 16 into the first seal gap 34. This means may comprise a scraper ring 68 or the like arranged in a groove in the wall of the first spatial section. Additionally, the apparatus may include an annular space 67 closer to the first pump chamber 16, the annular space being provided with a conduit to direct the fuel material for further processing. Since second pump chamber 16' is within second spatial section 30 ", they are referred to commonly below.

The pump 10 is provided with means for conveying fuel material away from the second pump chamber 16'. Thus, first, the pump 10 is provided with a vent flow path 36. Vent flow path 36 extends through body 18 of the pump and connects second pump chamber 16 formed in second spatial segment 30 "to the exterior of body 18. The vent flow path 36 is configured to allow gas to be admitted into the second spatial section 30 "driven by the reciprocating movement of the piston member. The pump 10 is further provided with a vent flow path 38 connecting the second pump chamber 16' to the exterior of the body 18, the vent flow path 38 being configured to convey fuel material entering the second pump chamber 16' or the second spatial section 30 "via the seal gap 34 away from the second spatial section 30", i.e., the second pump chamber 16 '.

In the embodiment shown in fig. 1, vent flow path 36 is provided with a one-way valve 40, the one-way valve 40 allowing gas to flow in vent flow path 36 in a direction toward second spatial section 30 "and preventing fluid from flowing back from second pump chamber 16'. The vent flow path 36 has an inlet to the periphery of the pump 10. The discharge flow path 38 is provided with a check valve 42, respectively, the check valve 42 being configured to allow flow to exit the second spatial section 30 "via the discharge flow path 38. During the compression stroke, the volume of the second pump chamber 16' is reduced and, accordingly, it is pressurized. Gas and liquid within second pump chamber 16 'are forced out of second pump chamber 16' via discharge check valve 42. During the pump's suction stroke, the second pump chamber 16' expands, causing suction through the vent check valve 40.

In fig. 1, the piston member 28 is in its first limit position in which the first pump chamber 16 has its maximum volume. The piston member 28 may move as depicted by arrow 44 under the action of external forces, which may be provided directly by operation of the engine.

The piston member 28 is provided with a coaxial sleeve member 46, the sleeve member 46 being connected to the second end 28 "of the piston member 28 and having a closed end, i.e. a bottom 58. The bottom portion 58 of the sleeve member 46 extends radially to the piston member 28. The sleeve member 46 may be an integral part of the second end 28 "of the piston member 28 or a separate part from the second end 28" of the piston member 28. Thus, the bottom portion 58 of the sleeve member 46 is common with the piston member 28 and it serves to receive the force required to reciprocate the piston member 28 in the pump 10. The sleeve member 46 is arranged such that an annular space is provided between the sleeve member 46 and the piston member 28, which annular space now at least partly forms the second pump space 16'. The sleeve member 46 is open towards the first end 28' of the piston member 28. The sleeve member 46 is a spatial section 30 "such that the radially inner wall of the second spatial section 30" and the radially outer wall of the sleeve member 46 abut each other, thereby providing the second sealing gap 35. The wall of the second spatial section 30 "guides the sleeve member 46 of the piston member 28 in the body 18 when the piston member 28 and the sleeve member are moving along the central axis 32.

The main body 18 of the pump 10 is provided with a cylindrical extension 48 towards the second end of the piston member 28, the cylindrical extension 48 being coaxial with the first spatial section 30'. The cylindrical extension 48 has an axial length in the direction of the central axis 32 and an outer diameter that is less than the second diameter D2. The cylindrical extension 48 extends axially into the second spatial section 30 ". At this time, when mounted to the internal combustion engine, the external force 44 is advantageously generated by the power system of the engine. The piston member 28 is thus in a connection that normally forms a mechanical force transmission indirectly with the crankshaft of the engine. In practice, this means that the mechanical force transmission is lubricated by the engine lubricant. The pump 10 is provided with means for conveying fuel material away from the second pump chamber 16' and any fuel material escaping through the seal gap 34 will not be able to enter the lubricating oil of the engine.

As shown in fig. 1, the pump 10 is configured to be mounted such that the first end 28' of the piston member 28 is horizontally below the second end 28 "of the piston member 28 and the central axis 32 is in an inclined position. In fig. 1, the oil scraper ring 68 is shown arranged in an annular space arranged to minimize fuel flow into the second space section 30 ". There is another annular space 67 closer to the first pump chamber 16, and the fuel discharge passage 66 extends from the annular space 67 to the outside of the body 18. The drain passage serves as a fuel recovery point. This arrangement reduces the amount of fuel flowing through the first seal clearance 34 to the second pump space 16 ", since a large portion of the fuel is directed to the fuel drain passage 66.

In the pump 10, the second spatial section 30 "is provided with a liner 70, a first end of the liner 70 is attached to the inner surface of the body 18 at the second spatial section 30" and is provided with a section having a smaller diameter than the outer surface of the second spatial section 30 ", such that an annular space is provided between the liner 70 and the inner surface of the second spatial section 30". The first end of the bushing is attached to the main body 18 on the side of the first end 28' of the piston member 28. The piston member 28 comprises a sleeve member 46, the sleeve member 46 being arranged in the second space section 30 "such that the desired guiding and sealing is provided. In the second space section 30 ", the inner wall of the second space section 30" and the wall of the sleeve member 46 are arranged against each other, thereby providing a second sealing gap 35 between these walls, respectively. The sleeve member 46 is arranged to extend into said annular gap 60 formed by the wall of the bushing 70 and the second spatial section 30 ". In this way, the sleeve 70, along with the sleeve member 46 and the piston member 28, form the boundary of the second pump chamber 16 ". The cooperation of the sleeve member 46 extending into the annular gap between the bushing 70 and the second spatial section 30 "is such that the radially inner wall of the annular gap, i.e. the radially outer wall of the bushing 70 and the radially inner wall of the sleeve member 46, abut against each other, thereby providing a third sealing gap 37.

A third spatial section 60 is arranged radially in the annular gap between the bushing 70 and the inner wall of the body 18 and the sleeve member 49, the sleeve member 49 forming the boundary of the third spatial section. The third spatial section 60 is used for lubricating the pump 10. The third spatial segment is also an annular space. The pump 10 is provided with a lubricating medium supply passage 62 and a lubricating medium discharge passage 64. The lubricating medium supply passage 62 is disposed at a position that facilitates supply of the lubricating medium (typically, oil) to the second seal gap 35. The lubricating medium discharge channel 64 is positioned so as to open into the third spatial section 60. The minimum volume of the third spatial section 60 and the location and/or dimensions of the lubricating medium supply channel 62 and the lubricating medium discharge channel 64 are configured to allow a lubricating medium pool to form in the third spatial section, but prevent the third spatial section from being completely filled with lubricating medium. In particular, the lubricating medium supply channel 62 and the lubricating medium discharge channel 64 are dimensioned such that the flow rate of the lubricating medium out of the third spatial section 60 is at least permanently greater than the flow rate of the lubricating medium into the third spatial section 60. The lubrication medium supply passage 62 is connected to the lubrication system of the engine and is therefore configured to receive pressurized lubrication medium.

The sealing effect of the above sealing gap may be based on the surface quality and/or dimensional tolerances of the components and/or individual sealing elements (such as O-rings or lip seals).

In fig. 2, a high-pressure pump assembly 100 is shown, in which high-pressure pump assembly 100 at least two piston pump units 10 are assembled. The pump unit 10 shown in fig. 2 is a high-pressure pump according to fig. 1. The pump unit 10 is here in a downwardly facing v-shaped configuration. If there are more than two pump units, they are arranged in two linear groups.

The pump assembly is provided with a drive shaft 110, the drive shaft 110 operating the piston pump unit 10 coupled thereto. The drive shaft 110 is a crankshaft having an eccentric portion 112, the drive shaft 110 being coupled to the piston member 28 of the pump unit 10 via the eccentric portion 112. The drive shaft 110 of the pump assembly may be driven by an engine, or it may be provided with, for example, an electric motor (not shown) to operate the pump assembly 100. The assembly 100 includes a housing 102, and a shaft 110 is mounted in the housing 102 with bearings.

The high pressure pump assembly 100 includes a drive shaft lubrication system 114, the drive shaft lubrication system 114 being adapted to deliver lubricant to the bearings of the shaft. The pump assembly further comprises a pump unit lubrication system 116 and at least one inlet 115 for pressurized lubricant, the lubrication system being connectable via the inlet 115 to the lubrication system of the engine, in which the high pressure fuel pump is mounted. The drive shaft lubrication system 114, when used, is connected to the lubrication system of the engine to deliver pressurized lubricant.

The pump assembly 100 according to the present invention is configured such that collection of fluid discharged from the pump assembly (i.e. so-called leaking fuel material and lubricating medium) occurs by means of gravity. The term leaked fuel refers to fuel that has reached the fuel recovery point along the first seal gap 34. In each of the pump units, lubricant is used to provide a lubricating effect in the first and

second seal gaps

34, 35. In the pump, the lubricant is collected by gravity drainage and is delivered as a lubricant return flow. Correspondingly, the fuel material flowing through the first sealing gap 34 is collected and transported by means of gravity drainage. Thus, the pump unit 10 is configured to discharge the lubricant and fuel material by gravity. The pump assembly is provided with a first accumulator conduit 120, the first accumulator conduit 120 being configured to receive lubricant from the drive shaft lubrication system 114 and the pump unit lubrication system 116. In addition, the pump assembly 100 is provided with a second collector conduit 122 and a third collector conduit 124, the second collector conduit 122 being configured to receive leakage fuel from the piston pump unit, and the third collector conduit 124 being configured to receive fuel mist from the second pump chamber 16' of the piston pump unit 10. The first collector conduit 120, the second collector conduit 122, and the third collector conduit 124 are separate from one another such that the fluids do not mix with one another in an undesirable manner. The first collector duct 120, the second collector duct 122 and the third collector duct 124 are arranged horizontally in a lower position with respect to the pump unit, so that there is a substantially continuous inclined flow passage from the pump unit to said ducts. The first collector conduit is arranged vertically below the outlet of the drive shaft lubrication system, the second collector conduit is arranged vertically below the outlet of the piston pump unit, and the third collector conduit is arranged vertically below the outlet of the piston pump unit.

The first, second and third collector conduits are arranged in a fluid collector block 118, the fluid collector block 118 being adapted to receive the discharged fluids and to convey them for further processing. This further processing advantageously means reusing the fluid in the engine. The collector block is a unitary structure in which the collector conduit is arranged substantially from one end of the collector block to the other end thereof.

In the embodiment of fig. 2, the fluid collector block 118, the first 120, second 122 and third 124 collector ducts in the fluid collector block are arranged to extend parallel to the drive shaft 110 of the pump assembly 100 from one end of the pump assembly 100 to the other end thereof, so that the discharge means (i.e. the outlet of the collector ducts) can be arranged at one end of the collector block, which is common for all pump units 10 in the assembly 100.

The high pressure fuel pump assembly comprises several piston pump units 10 in two sets of pistons in a shape configuration, and a fluid collector block is arranged between the two sets of pistons. Obviously, the pump assembly may comprise only one set of piston pump units arranged in rows.

The fluid collector block 118 is provided with several fluid interfaces 126 and the piston pump unit 10 is provided with corresponding fluid interfaces 126', wherein these fluid interfaces cooperate with each other such that a sealed fluid communication is formed between the fluid collector block 118 and the piston pump unit 10. These fluid interfaces are provided with suitable seals, such as O-rings, so that the fluids do not leak or mix with each other when connected to each other. The fluid interface connects more than one fluid conduit between the pump unit 10 and the fluid collector block 118. In connection with each of the fluid interfaces, the fluid collector block 118 is provided with a first channel 121 extending from the first collector conduit 120 to the fluid interface 126 and from the fluid interface 126 to the first collector conduit 120, the first channel being in fluid communication with the lubricating medium discharge channel 64 of the fuel pump unit 10 via the fluid interface 126. The fluid trap block 118 is provided with a second passage 123 extending from the second trap conduit 122 to a fluid interface 126, respectively, wherein the second passage is in fluid communication with the fuel discharge passage 66 of the fuel pump unit 10. In addition, the fluid collector block 118 is provided with a third passage 125 extending from the third collector conduit 124 to a fluid interface 126, wherein the third passage is in fluid communication with the fuel discharge path 38 of the fuel pump unit 10, which is configured to convey fuel material entering the second pump chamber 16' via the seal gap 34. The fuel entering the second pump chamber 16' is typically a fuel fog.

The fluid interfaces 126' of the piston pump unit 10 are directed to open into the direction between the groups of pump units 10 and the fluid collector block is provided with several fluid interfaces 126, which fluid interfaces 126 are in two rows, so that they are simultaneously connected to the respective fluid interfaces of the group of pistons.

In fig. 2, the fluid collector block 118 is disposed below the drive shaft 110 and between the sets of pump units 10.

As further shown in fig. 2, the fluid collector block 118 is provided with a fluid coupling 128 between the fluid collector block 118 and the housing 102 of the pump assembly. The housing of the assembly 100 is provided with corresponding fluid couplings 128', wherein the fluid couplings 128, 128' cooperate with each other such that a sealed fluid communication is formed between the fluid collector block 118 and the pump assembly housing 102. There is a fourth passage 129 in the collector block 118 extending from the first collector conduit 120 to the fluid coupling 128, wherein the fourth passage 129 is in fluid communication with the lubrication medium drain passage of the housing of the fuel pump assembly 100.

While the invention has been described herein by way of examples in connection with what are at present considered to be the most preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various combinations or modifications of its features and several other applications included within the scope of the invention as defined in the appended claims. When the combination of details mentioned in connection with any of the above embodiments with another embodiment is technically feasible, these details can be used in connection with the other embodiment.

Claims

1. A high-pressure fuel pump assembly (100) for an internal combustion piston engine, comprising a drive shaft lubrication system (114), a pump unit lubrication system (116) and at least one inlet (115) for pressurized lubricant and several piston pump units (10) driven by a drive shaft (110) of the pump assembly (100), characterized in that the pump assembly (100) is provided with a first collector conduit (120) configured to receive lubricant from the pump unit lubrication system (116) and a second collector conduit (122) configured to receive leaked fuel from the piston pump units and a third collector conduit configured to receive fuel mist from the piston pump units.

2. The high pressure fuel pump assembly (100) of claim 1, wherein the first, second and third collector conduits (120, 122, 124) are arranged in a fluid collector block (118) releasably attached to the pump unit (10).

3. The high pressure fuel pump assembly (100) of claim 1, wherein the first accumulator conduit (120) is configured to receive lubricant from the drive shaft (110) lubrication system and from the pump unit lubrication system (116).

4. The high pressure fuel pump assembly (100) according to claim 1, wherein the first collector duct (120), the second collector duct (122) and the third collector duct (124) are arranged horizontally in a lower position with respect to the pump unit (10) such that there is a substantially continuous inclined flow channel arranged from the pump unit (10) to the ducts (120, 122, 124).

5. The high pressure fuel pump assembly (100) of claim 1, wherein the first accumulator conduit (120) is arranged vertically below an outlet of the drive shaft lubrication system (110), the second accumulator conduit (122) is arranged vertically below an outlet of the piston pump unit (10), and the third accumulator conduit (124) is arranged vertically below an outlet of the piston pump unit (10).

6. The high-pressure fuel pump assembly (100) according to claim 1, wherein the high-pressure fuel pump assembly (100) comprises several piston pump units (10) in-line.

7. The high pressure fuel pump assembly (100) of claim 1, wherein the high pressure fuel pump assembly (100) comprises several piston pump units (10) in two sets of pistons in a v-shaped configuration, and the fluid collector block is arranged between the two sets of pistons.

8. The high-pressure fuel pump assembly (100) according to claim 1, characterized in that the fluid collector block is provided with several fluid interfaces (126) and the piston pump unit (10) is provided with corresponding fluid interfaces (126'), wherein the fluid interfaces are fitted to each other such that when the fluid interfaces are coupled, a sealed fluid communication is formed between the fluid collector block (118) and the piston pump unit (10).

9. The high-pressure fuel pump assembly (100) according to claims 7 and 8, characterized in that the fluid interfaces (126') of the piston pump units (10) are directed to open into a direction between the groups of the pump units (10), and the fluid collector block (118) is provided with several fluid interfaces (126), the several fluid interfaces (126) being in two rows, such that the several fluid interfaces are simultaneously connected to respective fluid interfaces of the groups of the piston pumps (10).

10. The high pressure fuel pump assembly (100) according to claims 7 and 8, wherein the fluid collector block is arranged below the drive shaft (110).