DE102012223935A1 - Rotary piston pump e.g. high-pressure pump for conveying fluid e.g. fuel to internal combustion engine, has an actuator for variable control and/or regulation of bypass channel, to integrate routable volume flow of fluid into channel - Google Patents

Abstract

The pump (1) has an impeller, and a working chamber divided into an inflow workspace and an outflow workspace. The inflow workspace has an inflow duct for introducing the fluid to be conveyed. The outflow channels are opened in outflow workspace for discharging pumped fluid from outflow workspace. A bypass channel is formed from first outflow channel to inflow duct. An actuator for variable control and/or regulation of bypass channel is formed in the housing for integrating the routable volume flow of fluid into the bypass channel. Independent claims are included for the following: (1) a high-pressure injection system for internal combustion engine; and (2) a method for operating a high-pressure injection system.

Description

The present invention relates to a rotary piston pump according to claim 1, a high-pressure injection system according to claim 10 and a method for operating a high-pressure injection system according to claim 12.

State of the art

Rotary piston pumps with electric motor are used for various technical applications for pumping a fluid. For example, prefeed pumps serve as fuel pumps for conveying fuel to a high-pressure pump.

In high-pressure injection systems, gerotor pumps with an internal gear and an eccentrically mounted external gear are used as prefeed pumps. In this case, the gerotor pumps have an inflow channel which opens into an inflow working space to introduce the fluid to be conveyed into the inflow working space and has an outflow channel which opens into an outflow working space to discharge the fluid to be conveyed from the outflow working space. The Zuströmarbeitsraum thus represents a suction side of a working space of the gerotor pump and the Abströmarbeitsraum represents a pressure side of the working space.

In high-pressure injection systems with a high-pressure pump and an electric prefeed pump as a gerotor pump, it is known that the fuel is introduced from the prefeed pump into a lubricating space of the high-pressure pump and fed to an inlet channel of the high-pressure pump. The control and / or regulation of the amount of fuel delivered by the high-pressure pump takes place through a metering unit. Moreover, it is known to control the flow rate of the high pressure pump without a metering unit and or regulate. This is an electric prefeed pump whose capacity is controllable and / or regulated. In this case, in turn, the fuel is supplied by the prefeed pump from a fuel tank to the lubricating space and the inlet channel of the high-pressure pump. Such control of the amount of fuel delivered by the high pressure pump without a metering unit is referred to as Feed Pump Control (FPC).

From the DE 36 24 532 C2 For example, there is known a vane or internal gear pump having a plurality of sealed delivery cells whose volume changes from a minimum to a maximum value and back during one revolution. The pump is used in particular for fuel delivery of an internal combustion engine. With axially entering into the feed cells suction and pressure channels, the mouth cross-sections are designed for a promotion without internal compression, but such is created by against axial surfaces of the pump parts applied, check valves forming fixed thrust washers.

From the DE 34 06 349 A1 a displacement machine with at least two gear machines is known, which is associated with its own or common hydraulic circuit, and their common flow is variable by a control means, wherein the control means is arranged in a housing part of the positive displacement machine.

The DE 299 13 367 U1 shows an internal gear pump with at least one internally toothed ring gear and a meshing, externally toothed impeller, with or without sickle, and with an electric drive, which is formed by the ring gear disposed inside a rotor of a brushless electric motor and the rotor adjacent to a stator is, wherein the rotor containing the ring gear is rotatably supported on the outside by a bearing or a sliding bearing, wherein the stator is shielded and sealed relative to the rotor and the interior of the pump characterized in that the located between the stator and rotor bearings or bearings for liquid impermeable and is tightly connected at its two end faces in each case with a cover.

Disclosure of the invention

Advantages of the invention

Inventive rotary piston pump, in particular gear pump, for conveying a fluid, comprising at least one impeller with conveying elements, of which a rotational movement about a rotational axis is executable, a present on the impeller working space, which is divided into an inflow working space and in a Abströmarbeitsraum, one in the Zuströmarbeitsraum opening inflow channel for introducing the fluid to be conveyed into the Zuströmarbeitsraum and a first outflow and second outflow as separate in the Abströmarbeitsraum outflow channels for deriving the fluid to be pumped from the Abströmarbeitsraum, a bypass channel from the first outflow to the inflow channel, preferably a housing, wherein in which an actuator for variable control and / or regulation of the volume flow through the bypass channel is integrated into the bypass channel. In an advantageous manner, the volume flow of fluid conducted through the bypass channel can thereby be changed and adapted to different operating states. As a result, a flexible use of the bypass channel is possible.

Suitably, the rotary piston pump of only one outflow on a bypass channel to the inflow channel.

In particular, with the actuator of the controllable by the actuator volume flow of fluid at an identical fictitious pressure difference for the fluid to the actuator changeable, preferably continuously variable. At the actuator of the rotary piston pump or the high-pressure injection system, a pressure difference occurs in the flow direction of the fluid through the bypass channel and in the flow direction of the fluid before the actuator, a higher pressure than after the actuator. With an identical pressure difference on the actuator can be passed through a change of the actuator, a different volume flow of fluid through the actuator and thus through the bypass channel. In particular, the larger the delivery rate and / or the rotational speed of the rotary piston pump, the greater is the pressure difference across the actuator, and vice versa.

In a further embodiment, the actuator is designed such that the greater the speed of the at least one impeller, the smaller is the volume flow of fluid through the actuator at an identical fictitious pressure difference for the fluid on the actuator and vice versa.

In an additional embodiment, the actuator is designed as a side channel pump with rotating blades and a side channel and the side channel forms at least partially, in particular completely, the bypass channel.

In one variant, the side channel is bounded by the at least one impeller and the side blade pump impeller blades are formed on the at least one impeller and the rotational movement of the at least one impeller on the side channel is opposite to the flow direction of the fluid from the first outflow channel through the side channel Aligned inflow channel and preferably the conveying blades are formed on a, preferably annular, impeller groove on the at least one impeller. At the at least one impeller in the side channel thus forms a partial flow, which reduces the flow of the fluid from the first outflow channel through the side channel to the inflow channel.

Suitably, the side channel of the housing, in particular housing cover, the rotary piston pump is limited. The side channel is thus limited by the housing and the at least one impeller, so that no additional components to limit the side channel are required.

In a further embodiment, the side channel as a, in particular annular, groove in the housing, in particular housing cover, the rotary piston pump is formed. In a master molding, in particular injection molding or casting, the housing so that the groove can be made particularly simple and inexpensive with due to the geometry of the injection molding tool or the mold for casting.

In a variant, the at least one impeller is the external gear of the rotary piston pump as an internal gear pump.

In a further embodiment, the rotary piston pump is a gear pump, preferably internal gear pump, in particular gerotor pump, and / or the rotary piston pump comprises an electric motor for driving the rotary piston pump, in particular the electric motor is integrated into the rotary piston pump, in particular the gear pump, in particular by a rotor of the electric motor Impeller forms, preferably by permanent magnets are installed in the impeller.

Inventive high-pressure injection system for an internal combustion engine, in particular for a motor vehicle, comprising a high-pressure pump, a high-pressure rail, a prefeed pump for conveying fuel from a fuel tank through a first fuel line to an inlet channel of the high pressure pump and through a second fuel line to a lubrication chamber of the high pressure pump and the Prefetch pump at least one impeller with conveying elements, of which a rotational axis about a rotational movement is executable, an existing on the impeller working space, which is divided into a Zuströmarbeitsraum and in a Abströmarbeitsraum, opening into the Zuströmarbeitsraum inflow channel for introducing the fluid to be conveyed in the Zuströmarbeitsraum comprising a first outflow channel and a second outflow channel as two separate outflow channels opening into the outflow working space and the first outflow channel discharges into the first fuel line and d he second outflow channel opens into the second fuel line, a bypass channel from the first outflow channel and / or the first fuel line to the inflow channel and / or a fuel line from the fuel tank to the inflow channel, wherein in the bypass channel an actuator for variable control and / or regulation of is integrated by the bypass channel conductive volume flow of fuel. With the actuator, the passage of fuel through the bypass channel to different operating conditions of the high-pressure injection system and the internal combustion engine can be adjusted. In particular, in a variable control and / or regulation of the by the Bypass channel conductive volume flow of fluid or fuel at a fictitious identical pressure difference across the actuator a different or modified volume flow of fluid or fuel through the actuator or can be conducted.

In particular, the actuator is designed to the effect that the greater the volume flow of fuel passed through the first outflow channel and / or the greater the number of revolutions of an impeller, in particular a gear, the prefeed pump, the smaller the volume flow of fuel controllable by the actuator with respect to a fictitious one identical pressure difference on the actuator and vice versa and / or the prefeed pump is designed as a rotary piston pump described in this patent application and / or with the high-pressure injection system described in this patent application process is executable. At a maximum required volume flow of fuel for the high-pressure pump or the inlet channel of the high-pressure pump, the actuator is almost completely closed, so that the predominantly total funded by the first outflow volume flow of fuel of the high-pressure pump is available. As a result, during operation of the prefeed pump for conveying the maximum volume flow of fuel for the high-pressure pump, only that rotational speed of the prefeed pump is required in order to convey this volume flow through the first outflow channel. At this speed of the prefeed pump for conveying the maximum volume flow of fuel through the first outflow channel to the high-pressure pump is also a sufficient volume flow at the second outflow channel for the lubricating space available. If the internal combustion engine or the high-pressure pump requires a smaller than the maximum volume flow, the speed of the prefeed pump can be reduced and at the same time the actuator is opened, thereby also allowing more fuel to flow through the bypass channel. Opening of the actuator is preferably required so that the prefeed pump is operated in a speed range in which a sufficient volume flow of fuel through the second outflow channel and thereby the lubricating space is passed and at the same time to the high pressure pump, a small or no volume flow of fuel is promoted the volume flow of fuel passed through the bypass passage is not delivered to the high pressure pump.

Method according to the invention for operating a high-pressure injection system, in particular a high-pressure injection system described in this patent application, comprising the steps of: conveying fuel with a prefeed pump from a fuel tank through an inflow working space, through an outflow working space and through a first outflow channel from the outflow working space and through a first fuel line to one Inlet opening of a high-pressure pump, conveying fuel with the prefeed pump from the fuel tank through the Zuströmarbeitsraum, through the Abströmarbeitsraum and through a second outflow channel from the Abströmarbeitsraum and through a second fuel line to a lubrication chamber of the high pressure pump, passing fuel through a bypass passage from the first outflow channel and / or the first fuel line to the inflow channel and / or to a fuel line from the fuel tank in the Zuströmarbeitsraum, wherein with a Stell organ of the guided through the bypass channel volume flow of fuel is controlled and / or regulated.

Suitably, the fuel is separated from the Abströmarbeitsraum separated by the first and second discharge channel.

In a further variant, the fuel is conveyed with a gear pump described in this patent application, in particular gerotor pump, as a prefeed pump

The greater the rotational speed of the impeller of the prefeed pump is preferably, the smaller is the volume flow of fuel flowing through the bypass passage with respect to an identical fictitious pressure difference of the fuel to the actuator and / or the actuator is formed by a pump, in particular side channel pump, and by the pump , in particular side channel pump, the fuel from the inflow channel and / or a fuel line from the fuel tank to the inflow working space in the first outflow channel and / or in the first fuel line is promoted.

In one variant, the fuel is passed through a side channel of a side channel pump as an actuator and the side channel is at least partially, in particular completely, the bypass channel is formed and the side channel of the at least one impeller, in particular the external gear of the rotary piston pump as an internal gear pump, with conveying blades of the side channel pump limited and the rotational movement of the at least one impeller is aligned opposite to the flow direction of the fuel from the first outflow channel through the side channel to the inflow channel, so that on the rotating at least one impeller in the side channel a partial flow is formed from which the flow of the fuel from the reduces the first outflow through the side channel to the inflow, in particular the partial flow is formed the greater, the greater the speed of the at least one impeller.

In particular, in each position of the at least one impeller with the conveying elements substantially no fluid-conducting connection between the two outflow channels through the Abströmarbeitsraum. There is thus essentially no fluid-conducting connection between the two outflow channels through the outflow working space. This is made available in particular by a geometry or a distance of the two outflow channels, so that at least one delivery element of the impeller constantly seals within the outflow working space an outflow channel from the other outflow channel. Pressure surges on one outflow channel do not reach the other outflow channel.

In a further embodiment, the conveying elements are teeth of a toothed wheel.

Preferably, the internal gear pump comprises an internal gear having an internal gear and an external gear having an external gear, wherein the teeth of the internal gear mesh with the teeth of the external gear and the working space is formed between the internal gear and the external gear.

In an additional embodiment, the internal gear is mounted eccentrically to the external gear.

In one variant, the amount, in particular the volume, of the fluid delivered by the two outflow passages varies per revolution of the at least one impeller, in particular the amount of fluid passed through the first outflow passage is greater than the amount of fluid passed through the second outflow passage. From the rotary piston pump thus different volume flows can be made available at the first outflow channel and at the second outflow of the two separate outflow channels. The rotary piston pump can thereby provide two separate volume flows with a different volume flow as two different rotary piston pumps with a different flow rate available.

In particular, the delivery rate of the rotary piston pump, preferably with an integrated electric motor, can be controlled and / or regulated, in particular by the power and / or rotational speed of the electric motor being controllable and / or controllable.

In a supplementary variant, there is essentially no fluid-conducting connection between the first fuel line and the second fuel line. Pressure surges in the lubricating space thereby do not reach the inlet valve of the high-pressure pump and even in the case of pressure surges within the lubricating space due to the oscillating movement of the piston of the high-pressure pump, the function of the high-pressure pump at the inlet valve of the high-pressure pump is not restricted. The rotary piston pump is designed such that in any position of the impeller of the rotary piston pump there is substantially no fluid-conducting connection between the two outflow channels through the Abströmarbeitsraum the rotary piston pump. In particular, the gears of the gerotor pump constantly separate the Abströmarbeitsraum at the first outflow from the Abströmarbeitsraum at the second outflow from.

The bypass channel connects the first outflow channel or the first fuel line with the inflow channel. In certain operating conditions of the internal combustion engine in the motor vehicle, for. As in a downhill of the motor vehicle, it is necessary that no fuel is delivered through the first fuel line to the inlet valve of the high pressure pump, because in a Begabfahrt to the engine no fuel is required and still lubrication of the high-pressure pump is required due to the movement of moving parts in the high pressure pump. By means of the bypass channel, the fuel delivered through the first outflow channel can again be supplied to the inflow channel, so that no fuel reaches the inlet valve of the high-pressure pump and nevertheless fuel is passed through the lubricant space through the second outflow channel and by means of the actuator, the fuel can pass through the bypass channel Volumetric flow of fuel can be controlled and / or regulated.

In a further embodiment, the prefeed pump is a prefeed pump with an electric motor, so that the prefeed pump is driven by the electric motor and, in particular, the delivery rate of the prefeed pump can be controlled and / or regulated.

Suitably, the rotary piston pump is a rotary vane pump, a rotary lobe pump or a centrifugal pump.

In a supplementary variant, the at least one impeller represents the rotary piston of the rotary piston pump.

In a further embodiment, the rotary piston pump with electric motor is enclosed by the housing. The pump with electric motor thus has one or more parts housing and within the housing, the rotary piston pump is arranged with electric motor.

Suitably, the rotary piston pump with, preferably integrated, electric motor a, preferably electronic, control unit for controlling the energization of the electromagnets and / or the electric motor is a brushless or electronically commutated electric motor.

Suitably consists of the housing of the rotary piston pump and / or the housing of the high pressure pump and / or the inner and / or outer gear at least partially, in particular completely, made of metal, for. As steel or aluminum.

Brief description of the drawings

Hereinafter, embodiments of the invention will be described in more detail with reference to the accompanying drawings. It shows:

1 a cross section of a high-pressure pump for conveying a fluid,

2 a section AA according to 1 a roller with roller shoe and a drive shaft,

3 a highly schematic view of a high-pressure injection system,

4 a greatly simplified cross-section of the high-pressure pump with a prefeed pump,

5 a perspective view of a prefeed pump without housing and a stator,

6 an exploded view of the feed pump according to 5 with housing,

7 a cross-section of an inner and outer gear of the feed pump according to 5 .

8th a diagram of the flow rate Q ₁ and Q ₂ at the first and second outflow channel in dependence on the rotational speed n of the external gear of the prefeed pump according to 5 .

9 a partial longitudinal section of the feed pump according to 5 .

10 a plan view of the housing cover of the prefeed pump according to 5 and

11 a view of a motor vehicle.

Embodiments of the invention

In 1 is a cross section of a high pressure pump 1 shown for conveying fuel. The high pressure pump 1 serves to fuel, z. As gasoline or diesel, to an internal combustion engine 39 for a motor vehicle 38 ( 11 ) under high pressure. The from the high pressure pump 1 producible pressure is for example in a range between 1000 and 3000 bar.

The high pressure pump 1 has a drive shaft 2 with two cams 3 on that around an axis of rotation 26 performs a rotational movement. The rotation axis 26 lies in the drawing plane of 1 and is perpendicular to the plane of 2 , A piston 5 is in a cylinder 6 stored by a housing 8th the high pressure pump 1 is formed. A high pressure workroom 29 is from the cylinder 6 as a piston guide 7 , the housing 8th and the piston 5 limited. In the high pressure workroom 29 opens an inlet channel 22 with an inlet valve 19 and an exhaust duct 24 with an exhaust valve 20 , Through the inlet channel 22 with the inlet opening 21 the fuel flows into the high-pressure working space 29 in and through the outlet channel 24 with an outlet opening 23 the fuel flows under high pressure from the high-pressure working space 29 out again. The inlet valve 19 , z. As a check valve, is designed such that only fuel in the high pressure working space 29 can flow in and the exhaust valve 20 , z. B. a check valve, is designed such that only fuel from the high-pressure working space 29 can flow out. The volume of the high pressure workspace 29 is due to an oscillating stroke movement of the piston 5 changed. The piston 5 rests indirectly on the drive shaft 2 from. At the end of the piston 5 or pump piston 5 is a roller shoe 9 with a roller 10 attached. The roller 10 can perform a rotational movement, the axis of rotation 25 in the drawing plane according to 1 lies and perpendicular to the plane of 2 stands. The drive shaft 2 with the at least one cam 3 has a wave rolling surface 4 and the roller 10 a roller rolling surface 11 on.

The roller tread 11 the roller 10 rolls on the wave rolling surface 4 as a contact surface 12 the drive shaft 2 with the two cams 3 from. The roller shoe 9 is in one of the housing 8th formed roller shoe storage stored as a plain bearing. A feather 27 or spiral spring 27 as an elastic element 28 between the case 8th and the roller shoe 9 is clamped, brings on the roller shoe 9 a compressive force on, leaving the roller rolling surface 11 the roller 10 in constant contact with the shaft rolling surface 4 the drive shaft 2 stands. The roller shoe 9 and the piston 5 thus jointly carry out an oscillating lifting movement. The roller 10 is with a sliding bearing 13 in the roller shoe 9 stored.

In 3 is a highly schematic representation of a high-pressure injection system 36 for the motor vehicle 38 Shown with a high pressure rail 30 or a fuel rail 31 , From the high-pressure rail 30 or a fuel rail 31 the fuel is injected into the combustion chambers of the internal combustion engine by means of injectors (not shown) 39 injected. An electric feed pump 35 Promotes fuel from a fuel tank 32 through a first fuel line 33a to the inlet duct 22 and through a second fuel line 33b to a lubrication room 40 ( 4 ) of the high pressure pump 1 , A bypass channel 37 connects the first fuel line 33a with the fuel line 33 from the fuel tank 32 to the pre-feed pump 35 , The high pressure pump 1 is doing from the drive shaft 2 driven and the drive shaft 2 is a wave, z. B. a crankshaft or camshaft, the engine 39 , The delivery rate of the electric prefeed pump 35 is controllable and / or controllable, so that thereby to the inlet duct 22 subsidized amount of fuel can be controlled and / or regulated. The high pressure rail 30 serves to transport the fuel into the combustion chambers of the internal combustion engine 39 inject. The from the high pressure pump 1 Unnecessary fuel is through a fuel return line 34 back in the fuel tank 32 returned.

4 shows a part of the high-pressure injection system 36 , Inside the case 8th the high pressure pump 1 is the lubrication room 40 educated. In the lubrication room 40 are the drive shaft 2 , the roller 10 , the roller shoe 9 (not in 4 ) and partially the piston 5 arranged. Through the through the lubricating space 40 Guided fuel will be these components 2 . 5 . 9 and 10 lubricated by the fuel. The through the second fuel line 33b in the lubrication room 40 Fuel introduced is through the fuel return line 34 from the lubricating space 40 discharged from the fuel tank 32 fed again ( 4 ). In 4 is that in 3 illustrated high-pressure injection system 36 in more detail without the high pressure rail 30 and without the internal combustion engine 39 shown. The from the pre-feed pump 35 from the fuel tank 32 sucked fuel is from the pre-feed pump 35 with a prefeed pressure, z. B. 4 bar, through the first fuel line 33a the inlet channel 22 the high pressure pump 1 fed. Furthermore, that of the prefeed pump 35 subsidized fuel during operation of the internal combustion engine 39 through the second fuel line 33b the lubricating space 40 supplied for lubrication, z. B. the drive shaft 2 , the roller 10 and the piston 5 , After flowing through the fuel through the lubricating space 40 the fuel is returned through the fuel return line 34 the fuel tank 32 fed. This allows these components 2 . 5 . 9 and 10 lubricated as well as cooled. The pre-feed pump 35 promotes in addition to the flow rate for the high-pressure pump 1 Fuel also an additional amount of fuel or volume flow for lubrication of the high-pressure pump 1 , ie the fuel passing through the lubricating space 40 flows.

The electric prefeed pump 35 has an electric motor 17 and a rotary piston pump 16 namely a gear pump 14 ie an internal gear pump 15 or gerotor pump 15 on ( 5 and 6 ). Here is the electric motor 17 the gerotor pump 15 in the gerotor pump 15 integrated. The high pressure pump 1 promotes fuel under high pressure, for example, a pressure of 1000, 3000 or 4000 bar, through a high pressure fuel line to a high pressure rail 31 , From the high-pressure rail 31 the fuel is under high pressure by one injector each a combustion chamber (not shown) of the internal combustion engine 39 fed. The electric motor 17 ( 5 and 6 ) of the electrical feed pump 35 is operated with three-phase current or alternating current and is controllable in power and / or regulated. The three-phase current or alternating current for the electric motor 17 is from a power electronics, not shown, from a DC voltage network of a vehicle electrical system of a motor vehicle 38 made available. The electric prefeed pump 35 is thus an electronically co-fed prefeed pump 35 ,

The electric prefeed pump 35 or gerotor pump 15 has a housing 42 with a housing pot 44 and a housing cover 43 on ( 6 ). Inside the case 42 the pre-feed pump 35 are the gerotor pump 15 as internal gear pump 15 or gear pump 14 and the electric motor 17 arranged. The housing pot 44 is with a recess 72 Mistake. The electric motor 17 has a stator 47 with windings 48 as electromagnets 49 and a soft iron core 70 as a soft magnetic core 68 that as a laminated core 69 is trained. Inside the stator 47 is the gerotor pump 15 as internal gear pump 15 with an internal gear 56 with an internal toothed ring 57 and an external gear 58 with an external tooth ring 59 positioned. The internal and external gear 56 . 58 makes a gear 54 and an impeller 52 and the inner and outer teeth ring 57 . 59 have teeth 55 as conveying elements 53 on. Between the inner and outer gear 56 . 58 a working room is formed 62 out. In the external gear 58 are permanent magnets 51 fitted so that the external gear 58 also a rotor 50 of the electric motor 17 forms. The electric motor 17 is thus in the gerotor pump 15 integrated or vice versa. The electromagnets 49 of the stator 47 are alternately energized, so that due to the contact with the electromagnet 49 resulting magnetic field of the rotor 50 or the external gear 58 in a rotational movement about a rotation axis 61 is offset.

The housing cover 43 serves as a warehouse 45 or thrust bearing 45 or slide bearing 45 for the internal or external gear 56 . 58 , In addition, the housing pot 44 and the housing cover 43 three holes each 71 in which not shown Screws for screwing together the housing pot 44 and the housing cover 43 are positioned, with a seal, not shown, the housing pot 44 and the housing cover 43 lie fluid-tight on each other. The recess 72 on the housing pot 44 serves to cut at the recess 72 electrical contact elements or lines to the electromagnet 49 respectively.

In 7 is the cross section of the internal gear 56 and the external gear 58 the gerotor pump 15 shown. Between the internal gear 56 and the external gear 58 the working space is formed 62 the internal gear pump 15 out. Will the inner and outer gear 56 . 58 rotated counterclockwise, with the inner and outer gears 56 . 58 Are mounted eccentrically to each other, forms on the inner and outer gear 56 . 58 ie between the inner and outer gears 56 . 58 , the workspace 62 out. At an angle range 73 of 180 ° forms a Zuströmarbeitsraum 63 from, at which the working space 62 increases and thereby a suction side of the internal gear pump 15 is present. At an angle range 74 of the workroom 62 arises the Abströmarbeitsraum 64 in which the working space 62 reduced and thereby a pressure side of the internal gear pump 15 arises. Into the inflow workspace 63 an inflow channel opens 65 , which on the housing 8th the internal gear pump 15 is trained. The inflow channel 65 has an angular range 18 less than 180 °. In the downstream workspace 64 opens a first outflow channel 66 and a second outflow channel 67 each with an angular range 46 , The inflow channel 65 and the first and second outflow channels 66 . 67 are in 7 each shown in dashed lines. From the Abströmarbeitsraum 64 can thus by two hydraulically separated outflow channels 66 . 67 the fuel hydraulically separated from the Abströmarbeitsraum 64 be derived. The sealing distance or the angular range 75 between the two outflow channels 66 . 67 ie the distance between the two outflow channels 66 . 67 , is chosen to the effect that on the one hand to no complete closing of the pumping rooms on the teeth 55 between the inner and outer gears 56 . 58 comes and thus to a blockage of gerotor pump 15 and on the other hand, no leakage between the two outflow channels 66 . 67 is present, so that in every position of the internal and external gear 56 . 58 no fluid-conducting connection between the two outflow channels 66 . 67 consists. There is thus essentially no fluid-conducting connection, in particular of the second outflow channel 67 to the first outflow channel 66 ,

The through the first outflow channel 66 Guided fuel is through the first fuel line 33a an inlet valve 19 the high pressure pump 1 fed and the through the second outflow channel 67 Guided fuel is passing through the second fuel line 33b the lubricating space 40 supplied ( 4 ). Due to the lack of fluid-conducting connection from the second outflow channel 67 in the first outflow channel 66 can thereby pressure fluctuations in the lubricating space 40 , which due to the oscillating movements of the piston 5 in the lubrication room 40 Do not occur through the gerotor pump 15 and the first fuel line 33a to the inlet valve 19 the high pressure pump 1 procreate. Even with strong pressure fluctuations and pressure surges in the lubricating space 40 is thereby a proper function of the inlet valve 19 guaranteed as a check valve and thus also a proper function of the high-pressure pump 1 , The delivery rate of the gerotor pump 15 is controllable and / or controllable, since these are controllable by a power electric motor 17 is driven. A complex and expensive metering unit is not required and only by controlling and / or regulating the delivery rate of the gerotor pump 15 can the capacity of the high pressure pump 1 controlled and / or regulated.

The first outflow channel 66 or the first fuel output 33a is through the bypass channel 37 fluid-conducting with the fuel line 33 from the fuel tank 32 to the gerotor pump 15 or to the inflow channel 65 the gerotor pump 15 connected. In certain operating conditions of the internal combustion engine 39 of the motor vehicle 38 It may be necessary for the gerotor pump 15 no fuel or volume flow Q ₁ 'to the high-pressure pump 1 but fuel through the lubrication space 40 to lead is. This is done by an actuator 41 as a side channel pump 76 the by bypass channel 37 flowing volume flow of fuel in the flow direction 79 enlarged and thereby the bypass channel 37 changed open and thus reaches up to a certain speed n _B or flow rate of gerotor pump 15 through the first outflow channel 66 delivered volume flow Q ₁ of fuel through the bypass channel 37 back to the fuel line 33 or the inflow channel 65 , thereby making the gerotor pump 15 with respect to the first outflow channel 66 completely shorted. Through the second outflow channel 67 is a certain flow or a certain volume flow Q ₂ of fuel through the lubricating space 40 promoted. Such an operating state is, for example, at a downhill of the motor vehicle 38 given. In 8th is in a diagram on the abscissa, the speed n of the inner or outer gear 56 . 58 and plotted on the ordinate of the volume flow Q. The ratio between the volume flow Q ₁ to the volume flow Q ₂ results from the length ratios of the first and second outflow channel 66 . 67 ,

In 8th is the one through the inlet opening 21 the high pressure pump 1 directed flow Q _'1 dashed shown as a curve. The solid line for Q ₁ sets the volume flow through the first outflow channel 66 and the solid line for Q ₂ represents the volume flow through the second outflow channel 67 or lubricating space 40 Up to a speed n _{B of} the internal or external gear 56 . 58 is at a partially open actuator 41 no fuel as volume flow Q ₁ 'to the inlet opening 21 promoted, because the entire through the first outflow 66 pumped fuel through the bypass channel 37 again the inflow channel 65 can be supplied. Only when the rotational speed n _B is exceeded does the fuel become the inlet port 21 the high pressure pump 1 promoted. Opening the actuator 41 thus causes a passage of fuel through the bypass passage 37 as volume flow Q _B , thereby passing through the inlet port 21 directed volume flow Q ₁ 'is reduced compared to the volume flow Q ₁ , ie Q ₁ ' = Q ₁ - Q _B.

In 8th is with Q _B through the bypass channel 37 directed volumetric flow of fuel shown. At the maximum speed n _{max of} the internal or external gear 56 . 58 occurs at the first outflow channel 66 in an almost completely closed actuator 41 the volume flow max Q ₁ on. Requires the high pressure pump 1 , z. B. due to a maximum torque request by the driver of the motor vehicle 38 , at the inlet opening 21 or the first fuel line 33a the maximum volume flow of fuel would be at a partially or fully open actuator 41 a part of the through the first outflow channel 66 subsidized fuel through the bypass channel 37 be derived and not the high pressure pump 1 are available, ie part of the pre-feed pump 35 consumed electrical energy would be unnecessarily consumed. For this reason, at the maximum demand of the volume flow Q ₁ 'fuel for the high-pressure pump 1 the actuator 41 almost completely closed, so that the substantially entire through the first outflow channel 66 delivered volume flow Q ₁ to fuel the high-pressure pump 1 is available. This is due to the prefeed pump 35 for the maximum volume flow of fuel for the high-pressure pump 1 a smaller volume flow Q ₁ at the first outflow channel 66 and a smaller maximum speed n _max required than an open actuator 41 , so that thereby electrical energy for the operation of the feed pump 35 can be saved. At the maximum volume flow of fuel for the high-pressure pump 1 and the almost completely closed actuator 41 becomes the prefeed pump 35 operated at the maximum speed n _max , so that also at the second outflow channel 67 the maximum volume flow Q ₂ occurs and for sufficient cooling and lubrication of the lubricating space 40 provides. At the speed n _{B of} the pre-supply pump 35 is through the second outflow channel 67 and the lubricating space 40 the minimum volume flow min Q ₂ promoted, which is required for cooling and lubrication. With a reduction of the speed n to a smaller speed than n _max , the volume flow Q _{B increases} .

In 9 and 10 is the side channel pump 76 as an actuator 41 shown. For illustrative reasons is a side channel 80 the side channel pump 76 in 6 not illustrated. The side channel 80 is as an annular, in cross-section substantially semicircular groove 77 in the housing cover 43 as a housing 42 the pre-feed pump 35 educated. The side channel 80 connects the first outflow channel 66 with the inflow channel 65 so that the bypass channel 37 completely from the side channel 80 is formed. In the manufacture of the housing cover 43 With aluminum molds can due to the geometry of the mold, the groove 77 for the side channel 80 easy and inexpensive to be produced with. The direction of rotation 78 of the external gear 58 is opposite to the flow direction 79 of the fuel from the first outflow channel 66 through the side channel 80 to the inflow channel 65 aligned, since at the first outflow channel 66 a greater pressure occurs than at the inflow channel 65 , The external gear 58 has a completely annular impeller groove 83 ( 9 ) on and in the impeller groove 83 are conveyor blades 81 for the side channel pump 76 formed so that the external gear 58 also a conveyor wheel 82 the side channel pump 76 forms. The axial end of the conveyor blades 81 corresponds in axial extent to the remaining end of the external gear 58 on the housing cover 43 so that the axial ends of the conveyor blades 81 outside the groove 77 on the housing cover 43 rest. The conveyor blades 81 are also completely continuous in the radial direction of the impeller groove 83 educated. This allows the fuel only through the groove 77 or the side channel 80 from the first outflow channel 66 to the inflow channel 65 flow and not through the impeller groove 83 ,

Due to the rotational movement of the external gear 58 forms within the side channel 80 one of the conveyor blades 81 produced partial flow and the flow direction of the fuel in the partial flow is opposite to the flow direction 79 aligned with the fuel. Further, in the groove 77 or the side channel 80 and between the conveyor blades 81 in the impeller groove 83 generates a circular flow, which amplifies the partial flow. The higher the speed n of the external gear 58 is, the greater the partial flow is formed, so that with the partial flow of the fuel in the side channel 80 opposite to the flow direction 79 is encouraged. The volume flow Q _B through the side channel 80 or the bypass channel 37 results from the total volume flow of the fuel in the partial flow and outside the partial flow with the flow direction 79 , The greater the speed n of the external gear 58 is, the smaller is the through the side channel 80 flowing volume flow Q _B or the farther is the actuator 41 as a side channel pump 76 closed and vice versa. At the maximum speed n _{max of} the external gear 58 is the Stelloran 41 almost completely closed, ie the volume flow Q _B is almost zero.

Overall, considered with the high-pressure injection system according to the invention 36 significant benefits. At a high or a maximum capacity of the pre-feed pump 1 to fuel to the high pressure pump 1 is due to the high speed of the feed pump 35 a sufficient volume flow of fuel Q ₂ through the lubricant space 40 passed and through the second outflow channel 67 directed. For this reason, it is in an operating state of the prefeed pump 35 at a high or maximum speed range of the pre-feed pump 35 not desired, fuel through the bypass channel 37 derive. For this reason, with the actuator 41 at a high or maximum speed range of the pre-feed pump 35 the bypass channel 35 at least partially closed so that thereby the whole or the substantially entire through the first outflow channel 66 directed volumetric flow of fuel of the high-pressure pump 1 is available. As a result, in this operating state, the energy consumption of the electric prefeed pump 35 be reduced. Even at a low volume flow request Q ₁ 'of fuel to the high pressure pump 1 a sufficient volume flow of fuel Q ₂ through the second outflow channel 67 to be able to guide, becomes the actuator 41 independently hydraulically opened by a reduction of the partial flow, so that thereby on the one hand to the high pressure pump 1 a small volume flow of fuel is conveyed, as part of the flow through the first outflow 66 funded volume flow Q ₁ through the bypass channel 37 is derived as a volume flow Q _B and on the other hand, a sufficient volume flow Q ₂ of fuel through the second outflow channel 67 can be promoted due to the speed n of the feed pump 35 for cooling and lubrication of the lubricating space 40 ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3624532 C2 [0005]
• DE 3406349 A1 [0006]
• DE 29913367 U1 [0007]

Claims (15)

Rotary piston pump ( 16 ), in particular gear pump ( 14 ), for conveying a fluid, comprising - at least one impeller ( 52 ) with conveying elements ( 53 ) of which about a rotation axis ( 61 ) a rotational movement is executable, - one on the impeller ( 52 ) existing work space ( 62 ) entering an inflow workspace ( 63 ) and in a downstream working space ( 64 ), - one in the Zuströmarbeitsraum ( 63 ) inflowing inflow channel ( 65 ) for introducing the fluid to be conveyed into the inflow work space ( 63 ) and a first outflow channel ( 66 ) and second outflow channel ( 67 ) as separated into the effluent working space ( 64 ) outflow channels ( 66 . 67 ) for diverting the fluid to be delivered from the Abströmarbeitsraum ( 64 ), - a bypass channel ( 37 ) from the first outflow channel ( 66 ) to the inflow channel ( 65 ), Preferably a housing ( 42 ), whereby, in the bypass channel ( 37 ) an actuator ( 41 ) for the variable control and / or regulation of the by the bypass channel ( 37 ) is integrated flow volume of fluid. Rotary piston pump according to claim 1, characterized in that with the actuator ( 41 ) by the actuator ( 41 ) conductive volume flow of fluid at an identical fictitious pressure difference for the fluid on the actuator ( 41 ), changeable, preferably continuously variable, is. Rotary piston pump according to claim 2, characterized in that the actuator ( 41 ) is designed such that the greater the rotational speed of the at least one impeller ( 52 ) is, the smaller the by the actuator ( 41 ) conductive volume flow of fluid at an identical fictitious pressure difference for the fluid on the actuator ( 41 ) and vice versa. Rotary piston pump according to one or more of the preceding claims, characterized in that the actuator ( 41 ) as a side channel pump ( 76 ) with rotating conveyor blades ( 81 ) and a side channel ( 80 ) and the side channel ( 76 ) at least partially, in particular completely, the bypass channel ( 37 ). Rotary piston pump according to claim 4, characterized in that the side channel ( 76 ) of the at least one impeller ( 52 ) and the conveyor blades ( 81 ) of the side channel pump ( 76 ) on the at least one impeller ( 52 ) are formed and the rotational movement of the at least one impeller ( 52 ) on the side channel ( 76 ) opposite to the flow direction ( 79 ) of the fluid from the first outflow channel ( 66 ) through the side channel ( 76 ) to the inflow channel ( 65 ) and preferably the conveyor ( 81 ) on a, preferably annular, impeller groove ( 83 ) on the at least one impeller ( 52 ) are formed. Rotary piston pump according to claim 4 or 5, characterized in that the side channel ( 80 ) of the housing ( 42 ), in particular housing cover ( 43 ), the rotary piston pump ( 16 ) is limited. Rotary piston pump according to claim 6, characterized in that the side channel ( 80 ) as an, in particular annular, groove ( 77 ) in the housing ( 42 ), in particular housing cover ( 43 ), the rotary piston pump ( 16 ) is trained. Rotary piston pump according to one or more of claims 5 to 7, characterized in that the at least one impeller ( 52 ) the external gear ( 58 ) of the rotary piston pump ( 16 ) as internal gear pump ( 15 ). Rotary piston pump according to one or more of the preceding claims, characterized in that the rotary piston pump ( 16 ) a gear pump ( 14 ), preferably internal gear pump ( 15 ), in particular gerotor pump ( 15 ), and / or the rotary piston pump ( 16 ) an electric motor ( 17 ) for driving the rotary piston pump ( 16 ), in particular the electric motor ( 17 ) in the rotary piston pump ( 16 ), in particular the gear pump ( 14 ), in particular by a rotor ( 50 ) of the electric motor ( 17 ) an impeller ( 52 ), preferably by permanent magnets ( 51 ) in the impeller ( 52 ) are installed. High-pressure injection system ( 36 ) for an internal combustion engine ( 39 ), in particular for a motor vehicle ( 38 ), comprising - a high-pressure pump ( 1 ), - a high-pressure rail ( 30 ), - a prefeed pump ( 35 ) for conveying fuel from a fuel tank ( 32 ) through a first fuel line ( 33a ) to an inlet channel ( 22 ) of the high-pressure pump ( 1 ) and a second fuel line ( 33b ) to a lubricating space ( 40 ) of the high-pressure pump ( 1 ) and the pre-feed pump ( 35 ) at least one impeller ( 52 ) with conveying elements ( 53 ) of which about a rotation axis ( 61 ) a rotational movement is executable, one on the impeller ( 52 ) existing work space ( 62 ) entering an inflow workspace ( 63 ) and in a downstream working space ( 64 ), one in the Zuströmarbeitsraum ( 63 ) inflowing inflow channel ( 65 ) to the Introducing the fluid to be conveyed into the inflow work space ( 63 ), a first outflow channel ( 66 ) and a second outflow channel ( 67 ) as two separate in the Abströmarbeitsraum ( 64 ) outflow channels ( 66 . 67 ) and the first outflow channel ( 66 ) into the first fuel line ( 33a ) and the second outflow channel ( 67 ) into the second fuel line ( 33b ), - a bypass channel ( 37 ) from the first outflow channel ( 66 ) and / or the first fuel line ( 33a ) to the inflow channel ( 65 ) and / or a fuel line ( 33 ) from the fuel tank ( 32 ) to the inflow channel 65 ), whereby, in the bypass channel ( 37 ) an actuator ( 41 ) for the variable control and / or regulation of the by the bypass channel ( 37 ) Flowable volume of fuel is integrated. High-pressure injection system according to claim 10, characterized in that the actuator ( 41 ) is designed such that the larger of the through the first outflow channel ( 66 ) guided volume flow of fuel and / or the greater the speed of an impeller ( 52 ), in particular gear ( 54 ), the prefeed pump ( 35 ) is, the smaller the by the actuator ( 41 ) controllable volume flow of fuel with respect to a fictitious identical pressure difference at the actuator ( 41 ) and vice versa and / or the feed pump ( 35 ) as a rotary piston pump ( 16 ) according to one or more of claims 1 to 8 and / or with the high-pressure injection system ( 36 ) A method according to claim 12 to 15 is executable. Method for operating a high-pressure injection system ( 36 ), in particular a high-pressure injection system ( 36 ) according to claim 10 or 11, comprising the steps of: - conveying fuel with a prefeed pump ( 35 ) from a fuel tank ( 32 ) through an inflow workspace ( 63 ), through a downstream working space ( 64 ) and by a first outflow channel ( 66 ) from the effluent working space ( 64 ) and through a first fuel line ( 33a ) to an inlet opening ( 21 ) a high pressure pump ( 1 ), - conveying fuel with the prefeed pump ( 35 ) from the fuel tank ( 32 ) through the inflow workspace ( 63 ), through the Abströmarbeitsraum ( 64 ) and by a second outflow channel ( 67 ) from the effluent working space ( 64 ) and a second fuel line ( 33b ) to a lubricating space ( 40 ) of the high-pressure pump ( 1 ), - Passing of fuel through a bypass channel ( 37 ) from the first outflow channel ( 66 ) and / or the first fuel line ( 33a ) to the inflow channel ( 65 ) and / or to a fuel line ( 33 ) from the fuel tank ( 32 ) into the inflow workspace ( 63 ), with an actuator ( 41 ) passing through the bypass channel ( 37 ) directed volume flow of fuel is controlled changed and / or regulated. A method according to claim 12, characterized in that the fuel with a gear pump ( 14 ), in particular gerotor pump ( 15 ), as prefeed pump ( 35 ) is conveyed according to one or more of claims 1 to 8 A method according to claim 12 or 13, characterized in that the greater the speed of the impeller ( 52 ) of the feed pump ( 35 ), the smaller the flow through the bypass channel ( 37 ) flowing volume flow of fuel with respect to a fictitious identical pressure difference of the fuel to the actuator ( 41 ) and / or the actuator ( 41 ) from a pump ( 76 ), in particular side channel pump ( 76 ), and by the pump ( 76 ), in particular side channel pump ( 76 ), the fuel from the inflow channel ( 65 ) and / or from a fuel line ( 33 ) from the fuel tank ( 32 ) to the inflow workspace ( 63 ) in the first outflow channel ( 66 ) and / or in the first fuel line ( 33a ). Method according to one or more of claims 12 to 14, characterized in that the fuel through a side channel ( 80 ) of a side channel pump ( 76 ) as an actuator ( 41 ) and from the side channel ( 80 ) at least partially, in particular completely, the bypass channel ( 37 ) and the side channel ( 80 ) of the at least one impeller ( 52 ), in particular the external gear ( 58 ) of the rotary piston pump ( 16 ) as internal gear pump ( 15 ), with conveyor blades ( 81 ) of the side channel pump ( 76 ) is limited and the rotational movement of the at least one impeller ( 52 ) opposite to the flow direction ( 79 ) of the fuel from the first outflow channel ( 66 ) through the side channel ( 80 ) to the inflow channel ( 65 ) is aligned so that at the rotating at least one impeller ( 52 ) in the side channel ( 80 ) a partial flow is formed from which the flow of the fuel from the first outflow channel ( 66 ) through the side channel ( 80 ) to the inflow channel ( 65 ), in particular the partial flow is formed the greater, the greater the rotational speed of the at least one impeller ( 52 ).

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