EP2872771B1 - High-pressure pump - Google Patents

Description

The present invention relates to a high-pressure pump according to the preamble of claim 1 and a high-pressure injection system according to the preamble of claim 10.

State of the art

In high-pressure injection systems for internal combustion engines, in particular in common-rail injection systems of diesel or gasoline engines, a high-pressure pump continuously ensures the maintenance of the pressure in the high-pressure accumulator of the common-rail injection system. The high-pressure pump can be driven, for example, by a camshaft of the internal combustion engine by means of a drive shaft. For the promotion of the fuel to the high-pressure pump Vorförderpumpen, z. B. a gear or rotary vane pump used, which are connected upstream of the high-pressure pump. The prefeed pump delivers the fuel from a fuel tank through a fuel line to the high pressure pump.

Amongst others, piston pumps are used as high-pressure pumps. In a housing, a drive shaft is mounted. Radially to pistons are arranged in a cylinder. On the drive shaft with at least one cam is a roller with a roller rolling surface, which is mounted in a roller shoe. The roller shoe is connected to the piston, so that the piston is forced to oscillate translational motion. A spring applies to the roller shoe a radially directed to the drive shaft force, so that the roller is in constant contact with the drive shaft. The roller is available the roller rolling surface on a shaft rolling surface as the surface of the drive shaft with the at least one cam in contact with the drive shaft. The roller is mounted by means of a sliding bearing in the roller shoe.

The high-pressure pump has a lubricant space formed within a housing and within the lubricant space, the drive shaft with the cam, the roller shoe and the roller is arranged. The lubricating space is traversed by fuel as a lubricating fluid for lubrication and cooling of the components, d. H. in particular the roller, the roller shoe and the drive shaft as well as the piston, which is slidably mounted on a piston guide on the housing. The funded by the feed pump fuel is thereby part of the high-pressure pump, d. H. an inlet channel, the high-pressure pump supplied and another part of the pumped by the feed pump fuel is passed through the lubricating space for cooling and lubrication of the components within the lubricating space. The housing comprises an opening for the passage and sliding bearing of the drive shaft and a blind hole for mounting the drive shaft. The drive shaft is slidably mounted on the blind hole and the opening by means of a bearing bush. There is a gap between the drive shaft and the two bearing bushes, in particular an annular gap through which the fuel flows for lubrication and cooling of the shaft plain bearing on the bearing bush. This fuel, which due to the clearance between the drive shaft and the bearing bush axially flows through this gap or gap, in particular annular gap, is thereby fed back to the fuel tank after flowing through a fuel return line. Due to a different bearing clearance also occurs a different volume flow of fuel through the two shaft plain bearings. However, this fuel flowing out of the lubricant space through the two waveguides does not suffice for sufficient cooling of the components within the lubricant space. For this reason, the housing is provided with an additional cooling throttle for the additional discharge of fuel from the lubricating space. This cooling throttle disadvantageously requires additional components and thus increases the manufacturing cost of the high-pressure pump.

The DE 10 2006 045 933 A1 shows a high-pressure pump for high-pressure fuel delivery. The high-pressure pump has a drive shaft with cams. Cylindrical rollers are supported by roller shoes and rest on the cams. The roller shoes are mounted by means of a plunger assembly in a bore of a part of the housing. The pump elements are attached to the plunger assembly. A coil spring presses the plunger assembly onto the cams.

From the DE 103 56 262 A1 and WO2005 / 054675 Radial piston pumps are known for fuel high pressure generation in fuel injection systems of internal combustion engines. In a pump housing, a drive shaft is mounted. Pistons are supported on the drive shaft, so that by rotating the drive shaft, the pistons are moved back and forth. Between the piston and the drive shaft tappets are arranged.

Disclosure of the invention Advantages of the invention

Inventive high-pressure pump for conveying a fluid, in particular fuel, for. B. diesel, comprising a housing, a drive shaft with at least one cam, at least one piston, at least one cylinder for supporting the at least one piston, wherein the at least one piston indirectly, in particular by means of at least one roller or a bucket tappet, on the drive shaft the at least one cam is supported, so that from the at least one piston a translational movement due to a rotational movement of the drive shaft is executable, a lubricating space within which the drive shaft is arranged with the at least one cam, for lubrication and cooling of the drive shaft, at least one shaft sliding bearing for storage the drive shaft with a fluid-conducting connection of a gap, in particular annular gap, between the shaft sliding bearing and the drive shaft to the lubricating space, so that the at least one shaft sliding bearing is lubricated and cooled with the lubricating fluid from the lubricating space, wherein in the Geh use and / or a bearing bush for the drive shaft at least one channel is incorporated for the additional drainage of liquid lubricant from the lubricant space. In the housing and / or the bearing bush for the drive shaft at least one channel is incorporated, thereby additionally in addition to the gap, in particular annular gap, due to a game between the drive shaft and the journal bearings fuel can be derived from the lubricating space in order to perform a sufficient cooling of the components within the lubricating space can. As a result, no additional or additional cooling throttle is required as a separate component on the high pressure pump on the lubricating space in an advantageous manner.

Expediently, the high-pressure pump does not comprise a cooling throttle as a separate component and, in particular, exclusively for this purpose. With the at least one channel can thus be additionally derived with existing components of the fuel from the lubricating space by the channel is incorporated into the housing and / or the bearing bush and thus no additional components are required.

According to the invention, the at least one channel is formed as a groove in the housing and / or the bearing bush and / or the housing has an opening or a blind hole for supporting the drive shaft and the at least one channel is formed on the opening or the blind hole.

The housing includes a body shell and a bearing cap housing. Suitably, the at least one channel is incorporated into the housing and / or the bearing bush by means of embossing and / or milling and / or by means of a laser. As a result, no additional components for the additional discharge of lubricating fluid from the lubricating space are required in an advantageous manner, because the at least one channel can be integrated into existing components. Preferably, the at least one groove is formed on a radial outer side of the bearing bush.

In a further embodiment, the groove in cross-section V-shaped, rectangular or circular segment-shaped.

In a supplementary embodiment, the at least one channel opens into a return bore and / or a return line. The derived by the at least one channel lubricating fluid, in particular fuel, is after deriving from the channel through the return line and / or the return bore fed back to a fuel tank.

Preferably, the at least one incorporated into the housing channel of the housing and the bearing bush is limited, since the at least one incorporated into the housing channel is incorporated in the region of a bearing surface of the bearing bush on the housing. The at least one channel is thus formed between the housing and the bearing bush.

In a variant, the at least one channel is delimited by the shaft sliding bearing and the drive shaft, since the at least one channel is incorporated in the shaft sliding bearing, in particular in the housing or the bearing bush. The at least one channel is thus formed between the shaft sliding bearing and the drive shaft. The shaft sliding bearing is formed for example by the housing or the bearing bush.

The high-pressure pump expediently comprises at least two or three channels, in particular per shaft sliding bearing for the drive shaft, and / or at least one channel opens into an annular channel and preferably the annular channel opens into a return bore and / or a return line.

Suitably, the at least one channel is aligned parallel or at an acute angle to a rotational axis of the drive shaft. Preferably, the acute angle is between 1 ° and 45 °, in particular between 1 ° and 30 °.

In a further embodiment, the annular channel is incorporated in an analogous manner as the at least one channel in the housing and / or the bearing bush.

According to the invention, the gap, in particular the annular gap, between the shaft plain bearing and the drive shaft is incorporated in a fluid-conducting connection through a return restrictor with the return bore and / or the return line and in particular the return restrictor in an analogous manner as the at least one channel is incorporated into the housing and / or the bearing bush , The return restriction throttle serves to ensure that the fuel exiting due to the clearance between the shaft sliding bearing and the drive shaft the amount is limited to obtain at a occurring due to wear and / or manufacturing tolerances very large backlash limitation of the lubricating fluid from the lubricating space due to the gap between the shaft sliding bearing and the drive shaft. Suitably, the return restrictor is incorporated in an analogous manner as the at least one channel in the housing and / or bearing bush for the drive shaft, ie, for example, as a groove on a radial outer side of the bearing bush. When incorporating the groove in the bearing bush so that both the channel and the return restriction throttle can be made and only by a different contact pressure during pressing grooves can be made with a different flow cross-sectional area for the channel and the return restriction throttle.

Inventive high-pressure injection system for an internal combustion engine, comprising a high pressure pump with a lubricating space, a high pressure rail, a prefeed pump for conveying a fuel from a fuel tank to the high pressure pump, wherein the high pressure pump is designed as a high pressure pump described in this patent application.

In a supplementary variant, the high-pressure injection system, in particular the high-pressure pump, comprises a pressure sensor for detecting the pressure in the lubricant space.

In a further variant, the delivery rate of the prefeed pump is controllable and / or controllable, in particular as a function of the pressure detected by the pressure sensor in the lubricant space and / or as a function of the volume flow of fuel required by the internal combustion engine. The delivery rate of the prefeed pump is controlled and / or regulated in such a way that on the one hand there is sufficient fuel for the internal combustion engine, ie a sufficient volume flow of fuel is supplied to the inlet channel of the high-pressure pump and on the other hand enough fuel flows through the lubricant space for lubrication and / or cooling as the second Volume flow and this second volume flow is dependent on the pressure within the lubricating space. For this reason, a sufficient volume flow of fuel can be passed through the lubricant space with the pressure sensor for cooling and / or lubrication of the components within the lubricating space.

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.

The drive shaft with the at least one cam is expediently a drive shaft which is circular in cross-section and which is mounted eccentrically to a central longitudinal axis of the drive shaft so that the axis of rotation is at a distance from the longitudinal axis. The longitudinal axis is arranged in cross section in the center of the circular drive shaft.

Suitably, the feed pump is a gear or rotary vane pump.

Brief description of the drawings

Fig. 1

einen Querschnitt einer Hochdruckpumpe zum Fördern eines Fluides,

Fig. 2

einen Schnitt A-A gemäß Fig. 1 einer Laufrolle mit Rollenschuh und einer Antriebswelle,

Fig. 3

eine stark schematisierte Ansicht eines Hochdruckeinspritzsystems,

Fig. 4

einen stark vereinfachten Querschnitt der Hochdruckpumpe mit einer Vorförderpumpe,

Fig. 5

einen Schnitt des Gehäuses der Hochdruckpumpe mit einer Öffnung und einem Sackloch zur Lagerung der Antriebswelle,

Fig. 6

einen Längsschnitt einer Gleitlagerung an der Öffnung mit einer Lagerbuchse,

Fig. 7

einen Längsschnitt der Gleitlagerung an dem Sackloch mit der Lagerbuchse,

Fig. 8

ein erstes Ausführungsbeispiel für den wenigstens einen Kanal,

Fig. 9

ein zweites Ausführungsbeispiel für den wenigstens einen Kanal,

Fig. 10

ein drittes Ausführungsbeispiel für den wenigstens einen Kanal,

Fig. 11

ein viertes Ausführungsbeispiel für den wenigstens einen Kanal,

Fig. 12

ein fünftes Ausführungsbeispiel für den wenigstens einen Kanal,

Fig. 13

ein sechstes Ausführungsbeispiel für den wenigstens einen Kanal,

Fig. 14

ein erstes Ausführungsbeispiel für den wenigstens einen Kanal mit einem Ringkanal,

Fig. 15

ein zweites Ausführungsbeispiel für den wenigstens einen Kanal mit einem Ringkanal,

Fig. 16

einen Teilquerschnitt der Lagerbuchse mit einem im Querschnitt V-förmigen Kanal,

Fig. 17

den Teilquerschnitt der Lagerbuchse mit einem im Querschnitt rechteckförmigen Kanal,

Fig. 18

einen Teilquerschnitt der Lagerbuchse mit einem im Querschnitt kreissegmentförmigen Kanal,

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

Fig. 1

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

Fig. 2

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

Fig. 3

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

Fig. 4

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

Fig. 5

a section of the housing of the high pressure pump with an opening and a blind hole for supporting the drive shaft,

Fig. 6

a longitudinal section of a sliding bearing at the opening with a bearing bush,

Fig. 7

a longitudinal section of the sliding bearing on the blind hole with the bearing bush,

Fig. 8

a first embodiment of the at least one channel,

Fig. 9

A second embodiment of the at least one channel,

Fig. 10

a third embodiment of the at least one channel,

Fig. 11

A fourth embodiment of the at least one channel,

Fig. 12

A fifth embodiment of the at least one channel,

Fig. 13

a sixth embodiment of the at least one channel,

Fig. 14

a first embodiment of the at least one channel with an annular channel,

Fig. 15

A second embodiment of the at least one channel with an annular channel,

Fig. 16

a partial cross section of the bearing bush with a cross-sectionally V-shaped channel,

Fig. 17

the partial cross section of the bearing bush with a rectangular cross-section channel,

Fig. 18

a partial cross section of the bearing bush with a circular cross-section-shaped channel,

Embodiments of the invention

In Fig. 1 is a cross section of a high-pressure pump 1 for conveying fuel shown. The high-pressure pump 1 serves to fuel, z. As gasoline or diesel, to an internal combustion engine 39 for a motor vehicle (not shown) to promote under high pressure. The pressure which can be generated by the high-pressure pump 1 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, which performs a rotational movement about a rotation axis 26. The axis of rotation 26 lies in the plane of Fig. 1 and is perpendicular to the plane of Fig. 2 , A piston 5 is mounted in a cylinder 6, which is formed by a housing 8 of the high-pressure pump 1. A high pressure working chamber 29 is bounded by the cylinder 6 as a piston guide 7, the housing 8 and the piston 5. Into the high-pressure working space 29 opens an inlet channel 22 with an inlet valve 19 and an outlet channel 24 with an outlet valve 20. Through the inlet channel 22 with an inlet opening 21, the fuel flows into the high-pressure working chamber 29 and through the outlet channel 24 with an outlet opening 23, the fuel flows under High pressure from the high pressure working chamber 29 again. The inlet valve 19, z. As a check valve, is designed to the effect that only fuel can flow into the working space 29 and the exhaust valve 20, z. B. a check valve is designed to the effect that only fuel can flow out of the working space 29. The volume of the high-pressure working chamber 29 is changed due to an oscillating stroke movement of the piston 5. The piston 5 is indirectly supported on the drive shaft 2 from. At the end of the piston 5 or pump piston 5, a roller shoe 9 is attached to a roller 10. The roller 10 can perform a rotational movement, the axis of rotation 25 in the plane according to Fig. 1 lies and perpendicular to the plane of Fig. 2 stands. The drive shaft 2 with the at least one cam 3 has a shaft rolling surface 4 and the roller 10 has a roller rolling surface 11.

The roller-running surface 11 of the roller 10 rolls on the shaft rolling surface 4 as a contact surface 12 of the drive shaft 2 with the two cams 3 from. The roller shoe 9 is mounted in a roller shoe bearing formed by the housing 8 as a sliding bearing. A spring 27 or spiral spring 27 as an elastic element 28, which is clamped between the housing 8 and the roller shoe 9, applies a compressive force to the roller shoe 9, so that the roller rolling surface 11 of the roller 10 is in constant contact with the shaft roller 9. Rolling surface 4 of the drive shaft 2 is. The roller shoe 9 and the piston 5 lead with it together an oscillating stroke movement. The roller 10 is mounted with a sliding bearing 13 in the roller shoe 9.

In Fig. 3 is a highly schematic representation of a high-pressure injection system 36 for the motor vehicle shown with a high-pressure rail 30 or a fuel rail 31. From the high-pressure rail 30 and a fuel rail 31, the fuel by means of valves (not shown) is injected into the combustion chamber of the engine 39 , An electric prefeed pump 35 delivers fuel from a fuel tank 32 through a first fuel line 33a to the intake passage 22 and through a second fuel passage 33b to a lubricating space 40 (FIG. Fig. 4 The high-pressure pump 1 is driven by the drive shaft 2 and the drive shaft 2 is connected to a shaft, for. As a crankshaft or camshaft, the engine 39 is connected. The delivery rate of the electric prefeed pump 35 can be controlled and / or regulated, so that thereby the amount of fuel delivered to the inlet channel 22 per unit time can be controlled and / or regulated. The high-pressure rail 30 serves to inject the fuel into the combustion chamber of the internal combustion engine 39. The fuel not required by the high-pressure pump 1 is returned to the fuel tank 32 through an optional fuel return line 34.

Fig. 4 shows a part of the high pressure injection system 36. Within the housing 8 of the high pressure pump 1, the lubricating space 40 is formed. In the lubricating space 40 are the drive shaft 2, the roller 10, the roller shoe 9 (not in Fig. 4 ) and partially the piston 5 is arranged. By means of the fuel passed through the lubricant space 40, these components 2, 5, 9 and 10 are lubricated by the fuel. The fuel introduced into the lubricant space 40 through the second fuel line 33b is returned to the fuel tank 32 through the fuel return line 34 from the lubricant space 40 ( Figure 4 ). In Fig. 4 is that in Fig. 3 shown high-pressure injection system 36 shown in more detail without the high-pressure rail 30 and without the internal combustion engine 39. The sucked by the prefeed pump 35 from the fuel tank 32 fuel is supplied from the prefeed pump 35 with a prefeed, z. B. 4 bar, supplied through the first fuel line 33 a the inlet channel 22 of the high-pressure pump 1. Furthermore, the of the Pre-feed pump 35 conveyed fuel during operation of the internal combustion engine 39 through the second fuel line 33b the lubricant chamber 40 is supplied to the 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 supplied through the fuel return line 34 to the fuel tank 32 again. As a result, these components 2, 5, 9 and 10 can be lubricated as well as cooled. The prefeed pump 35 thereby promotes not only the flow rate for the high-pressure pump 1 to fuel but also an additional amount of fuel for lubrication of the high-pressure pump 1, ie the fuel flowing through the lubricating space 40.

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 (FIG. Fig. 4 ). The high-pressure pump 1 delivers 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 of the fuel under high pressure from an injector combustion chamber (not shown) of Internal combustion engine 39 supplied. The electric motor 17 of the electric prefeed pump 35 is operated with three-phase current or alternating current and is controllable in the power and / or regulated. The three-phase current or alternating current for the electric motor 17 is provided by a power electronics, not shown, from a DC voltage network of a vehicle electrical system of a motor vehicle (not shown). The electric prefeed pump 35 is thus an electronically commutated prefeed pump 35.

The housing 8 of the high-pressure pump 1 is subdivided into a hull housing 46 and into a bearing cover housing 47 as separate components ( Fig. 4 and 5 ). The hull housing 46 is formed with a blind hole 45 and the bearing cover housing 47 or flange housing 47 has an opening 44 (FIG. Fig. 5 to 7 ). The opening 44 serves to form a shaft sliding bearing 18 for the drive shaft 2 and also for the implementation of the drive shaft 2 outside the lubricating space 40, so that thereby the drive shaft 2 can be mechanically connected for example with a camshaft, not shown, of the engine 39. The blind hole 45 only serves to provide a shaft sliding bearing 18 for the drive shaft 2 available. Both in the blind hole 45 and in the opening 44, a bearing bush 41 by means of a press fit on a support surface 49 on the housing 8, ie the hull housing 46 and the bearing cap housing 47, on or pressed. The bearing bush 41 thus forms on its radial inside the shaft sliding bearing 18 on which the drive shaft 2 rests.

There is a clearance between the drive shaft 2 and the two shaft plain bearings 18 on the two bearing bushes 41 at the opening 44 and the blind hole 45, thereby forming a gap 37, in particular an annular gap 38 between the drive shaft 2 and the bearing bush 41. Through this gap 37 of standing under a pressure of, for example, 4 to 5 bar fuel within the lubricating chamber 40 flows in the axial direction to an axial end of the shaft sliding bearing 18. At the blind hole 45 of the fuselage housing 46 as part of the housing 8, a drain hole 52 is also present , The flowing through the gap 37 between the drive shaft 2 and the bearing bush 41 fuel is thus collected at the drain hole 52 and then by the in Fig. 4 shown fuel return line 34 again fed to the fuel tank 32. At the opening 44 ( Fig. 6 ) Is a shaft seal, not shown, as well as other sealing means, for. As sealing rings, so that thereby from the annular gap 38 between the drive shaft 2 and the bearing bush 41 at the opening 44 effluent fuel can be collected and collected by a return restriction throttle 51 a return bore 48 is supplied. To the return bore 48, the fuel return line 34 is connected in an analogous manner as at the drain hole 52. The return restriction throttle 51 has a predetermined flow cross-sectional area, so that with an increase in the clearance and thus an enlargement of the gap 37, for example due to wear, the discharge of fuel through the gap 37 is limited. In an analogous manner, the drainage hole 52 is formed as a return restriction throttle 51. After flowing through the return restrictor 51 between the bearing bush 41 and the bearing cap housing 47, this fuel is supplied to the return bore 48 due to a corresponding fluid-conducting connection and the incorporated in the bearing cap housing 47 return bore 48 is fluidly connected to the fuel return line 34.

In the bearing bush 41 is on the radial outside by means of stamping, pressing or milling a groove 43 ( Fig. 6 ) incorporated. The bearing bush 41 is fixed by means of a press fit to the opening 44 of the bearing cap housing 47, ie on the support surface 49. The rotational position of the bearing bush 41 with respect to the bearing cap housing 47 is fixed, so that on the one hand due to the groove 43, a channel 42 between the bearing cap housing 47 and the bearing bush 41 is formed and this channel 42 is also hydraulically connected to the return bore 48, since the channel 42 due to the orientation of the bearing bush 41 opens relative to the bearing cap housing 47 in the return bore 48. Thus, in the return bore 48, both the channel 42 and the Rücklaufbegrenzungsdrossel 51. The return restrictor 51 is incorporated in an analogous manner as the channel 42 in the radial outer side of the bearing bush 41 by means of pressing or embossing. The fuel flowing out through the channel 42 is thus also supplied to the fuel return line 34 through the return bore 48.

In an analogous manner, the bearing book 41 also has a groove 43 on the blind hole 45 (FIG. Fig. 7 ) and thus formed between the bushing 41 and the body shell 46 also the channel 42. Through this channel 42 can be additionally derived fuel, which is also supplied through the drain hole 52 of the fuel return line 34 and thus the fuel tank 32. The flow cross-sectional area of the drainage bore 52 may optionally also be designed such that the drainage bore 52 also serves as a return restriction throttle 51.

The fuel delivered by the prefeed pump 35 is supplied on the one hand through the first fuel line 33a to the inlet channel 22 and through the second fuel line 33b the lubricating chamber 40. The lubricating chamber 40 is completely filled with fuel and the fuel is used to lubricate the components, eg. B. the drive shaft 2 and the roller shoe 9, and also for cooling these components. In order to ensure sufficient cooling of these components, a sufficient volume flow of fuel must be passed through the lubricating space 40. The flowing through the gap 37 fuel between the drive shaft 2 and the bearing bush 41 due to a clearance between the bearing bush 41 and the drive shaft. 2 flowing fuel is not sufficient in its volume flow for cooling the lubricating space 40. For this reason, can be derived from the lubricating chamber 40 through the two channels 42 which are incorporated on the radial outer side of the two bushings 41 in the form of grooves 43. In this case, this channel 42 is a cooling throttle without additional components to the high-pressure pump 1, because the channel 42 is integrated into existing components, namely by the groove 43 is incorporated into the bearing bush 41 on the outside.

In the Fig. 8 to 13 For example, views of bushing 41 in various embodiments are shown for channels 42. In Fig. 8 has the bearing bush 41 only one channel 42 and a groove 43 which is aligned parallel to a rotational axis 26 of the drive shaft 2. In the in Fig. 9 illustrated embodiment, the bearing bush 41 has two grooves 43 and in the in Fig. 10 illustrated embodiment, the grooves 43 are incorporated at an acute angle to the axis of rotation 26. This in Fig. 11 illustrated embodiment differs from the in Fig. 10 illustrated embodiment in that the two grooves 43 are interconnected by an additional groove and in Fig. 12 the two grooves 43 are also connected to each other by an additional groove, but aligned parallel to the axis of rotation 26. In the in Fig. 13 illustrated embodiment open two grooves 43 in the lubricating space 40 and these two grooves 43 then open into only one groove 43rd

In the FIGS. 14 and 15 are two embodiments for the formation of the bearing bush 41 in addition to at least one groove 43 also shown with an annular channel 50. This in Fig. 14 illustrated embodiment corresponds to in Fig. 8 illustrated embodiment and only differs in that an annular channel 50 is present. In an analogous way, this differs in Fig. 15 illustrated embodiment of the in Fig. 9 illustrated embodiment only in that an annular channel 50 is present. Analogously, the in Fig. 10 to 13 illustrated embodiments may be provided with a ring channel 50. In an annular channel 50, the bearing bush 41 in the opening 44 is not in its rotational angle position with respect to the return bore to the effect that the channel 42 opens directly into the return bore 48. At a Ring channel 50, the bearing bushing 41 does not have to be aligned in its rotational angular position on the bearing cap housing 48, but only the axial alignment of the bearing bush 41 must be made so that the annular channel 50 opens into the return bore 48.

The cross-sectional shape of the incorporated into the bearing bush 41 groove 43 is arbitrary and may for example be V-shaped ( Fig. 16 ), rectangular ( Fig. 17 ) or circular segment ( Fig. 18 ) be formed.

In a further, not shown embodiment, the groove 43 is not on the radial outer side of the bearing bush 41, but on the radial inner side of the bearing bush 41, d. H. formed on the shaft sliding bearing 48. The channel 42 is thereby bounded by the bearing bush 41 or the shaft sliding bearing 18 and the drive shaft 2. As a result, additional fuel can be discharged from the lubricant space 40.

In a further, not shown embodiment, the return flow restrictor 51 and the return bore 48 are on the blind hole 45 as in the embodiment in Fig. 6 formed at the opening 44 and the housing 8, that is, the body housing 46, has no drain hole 52 on the blind hole 45 on.

In the lubricating space 40, a pressure sensor 53 is present. The pressure sensor 53 detects the pressure of the fuel within the lubricating space 40, which is for example in the range of 4 to 5 bar. The delivery rate of the prefeed pump 35 is controllable and / or controllable and is controlled and / or regulated to the effect that a constant pressure of 4 to 5 bar is present in the lubricant space 40. In this case, the pressure in the lubricating chamber 40 can also be increased in order to discharge an increased amount of fuel from the lubricating space 40 by increasing the pressure to increase the cooling capacity with the volume flow of fuel passed through the lubricating space 40 and vice versa.

Overall, significant advantages are associated with the high-pressure pump 1 according to the invention. The high-pressure pump 1 does not have a separate cooling throttle for the additional discharge of fuel from the lubricating space 40 on, so that thereby the manufacturing cost of the high-pressure pump 1 can be lowered. In already existing components of the high-pressure pump 1, namely the bearing bush 41, a groove 43 is incorporated, thereby forming a channel 42 as a cooling throttle for the additional discharge of fuel from the lubricating space 40.

Claims (11)

1. High-pressure pump (1) for delivering a fluid, in particular fuel, for example diesel, comprising

   - a housing (8),

   - a drive shaft (2) with at least one cam (3),

   - at least one piston (5),

   - at least one cylinder (6) for the mounting of the at least one piston (5),

   - wherein the at least one piston (5) is supported indirectly on the drive shaft (2) with the at least one cam (3), such that the at least one piston (5) can perform a translational movement owing to a rotational movement of the drive shaft (2),

   - a lubricating chamber (40), within which the drive shaft (2) with the at least one cam (3) is arranged, for the lubricating and cooling of the drive shaft (2),

   - at least one shaft plain bearing (18) for the mounting of the drive shaft (2) with a fluid-conducting connection of a gap (37), in particular ring-shaped gap (38), between the shaft plain bearing (18) and the drive shaft (2) to the lubricating chamber. (40), such that the at least one shaft plain bearing (18) is lubricated and cooled by way of the lubricating fluid from the lubricating chamber (40), wherein

   - at least one duct (42) for the additional discharging of lubricating fluid from the lubricating chamber (40) is formed into the housing (8) and/or into a bearing bushing (41) for the drive shaft (2),

   characterized in that
   the at least one duct (42) is formed as a groove (43) in the housing (8) and/or in the bearing bushing (41),
   and
   the housing (8) has an opening (44) or a blind hole (45) for the mounting of the drive shaft (2) and the at least one duct (42) is formed at the opening (44) or on the blind hole (45), wherein the gap (37), in particular ring-shaped gap (38), between the shaft plain bearing (18) and the drive shaft (2) is connected in fluid-conducting fashion to the return bore (48) and/or to the return line (34) by way of a return restrictor throttle (51), and in particular,
   the return restrictor throttle (51) is formed into the housing (8) and/or into the bearing bushing (41).
2. High-pressure pump according to Claim 1,
   characterized in that
   the housing (8) comprises a body housing (46) and a bearing cover housing (47).
3. High-pressure pump according to Claim 2,
   characterized in that
   the groove (43) is of V-shaped, rectangular or circular-segment-shaped form in cross section.
4. High-pressure pump according to one or more of the preceding claims,
   characterized in that
   the at least one duct (42) opens into a return bore (48) and/or a return line (34).
5. High-pressure pump according to one or more of the preceding claims,
   characterized in that
   the at least one duct (42) formed into the housing (8) is delimited by the housing (8) and by the bearing bushing (41), because the at least one duct (42) formed into the housing (8) is formed in in the region of a support surface (49) of the bearing bushing (41) on the housing (8).
6. High-pressure pump according to one or more of the preceding claims,
   characterized in that
   the at least one duct (42) is delimited by the shaft plain bearing (18) and by the drive shaft (2), because the at least one duct (42) is formed into the shaft plain bearing (18), in particular into the housing (8) or the bearing bushing (41).
7. High-pressure pump according to one or more of the preceding claims,
   characterized in that
   the high-pressure pump (1) comprises at least two or three ducts (42), in particular per shaft plain bearing (18) for the drive shaft (2),
   and/or
   at least one duct (42) opens into a ring-shaped duct (50),
   and preferably
   the ring-shaped duct (50) opens into a return bore (48) and/or a return line (34).
8. High-pressure pump according to Claim 7, characterized in that
   the ring-shaped duct (50) is formed into the housing (8) and/or into the bearing bushing (41), analogously to the at least one duct (42).
9. High-pressure injection system (36) for an internal combustion engine (39), comprising

   - a high-pressure pump (1) with a lubricating chamber (40),

   - a high-pressure rail (30),

   - a predelivery pump (35) for delivering a fuel from a fuel tank (32) to the high-pressure pump (1),

   characterized in that
   the high-pressure pump (1) is in the form of a high-pressure pump (1) according to one or more of the preceding claims.
10. High-pressure injection system according to Claim 9,
    characterized in that
    the high-pressure injection system (36), in particular the high-pressure pump (1), comprises a pressure sensor (53) for detecting the pressure in the lubricating chamber (40).
11. High-pressure injection system according to Claim 9 or 10,
    characterized in that
    the delivery rate of the predelivery pump (35) is controllable and/or regulable in particular in a manner dependent on the pressure detected in the lubricating chamber (40) by the pressure sensor (53) and/or in a manner dependent on the volume flow of fuel required by the internal combustion engine (39).

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