EP3728850A1

EP3728850A1 - Fluid delivery device

Info

Publication number: EP3728850A1
Application number: EP18829267.6A
Authority: EP
Inventors: Reinhard Pippes
Original assignee: Eckerle Technologies GmbH
Current assignee: Eckerle Technologies GmbH
Priority date: 2017-12-22
Filing date: 2018-12-13
Publication date: 2020-10-28
Anticipated expiration: 2038-12-13
Also published as: DE102017223675B4; WO2019121307A1; DE102017223675A1; CN111566349A; US20200318635A1; EP3728850B1; CN111566349B; US11248602B2

Abstract

The invention relates to a fluid delivery device (1) having a forepump (2) and a main pump (3) fluidically connected to the forepump (2), wherein the forepump (2) can be driven via a forepump input shaft (13) and the main pump (3) can be driven via a pump input shaft (14). According to the invention, the forepump (2) has a forepump drive gear (16) coupled to the forepump input shaft (13) and a forepump delivery gear (17) interacting with the forepump drive gear (16) to deliver the fluid, wherein the forepump (2) and the main pump (3) are drivingly coupled to a common input shaft (15), and wherein the forepump delivery gear (17) and the main pump input shaft (14) are connected to one another via a connecting shaft (21) such that the forepump input shaft (13) is coupled directly to the drive shaft (15) and the main pump input shaft (14) is coupled to the drive shaft (15) via the connecting shaft (21).

Description

DESCRIPTION

Fluid delivery device

The invention relates to a fluid delivery device with a backing pump and a flow technically connected to the backing pump main pump, the backing pump via a pump input shaft upstream and the main pump are driven by a main pump input shaft.

From the prior art, for example, the document DE 10 2007 032 103 Al is known. This relates to a pump unit with a main pump and a variable in their volume displacement fad pump. To adjust the delivery volume of the fad pump is a lifting ring seen before. The cam ring is acted upon by a dependent on the inlet pressure of the main pump actuator.

It is an object of the invention to provide a fluid conveyor, which has advantages over known fluid conveyors, in particular an ideal vote of the backing pump and the main pump to each other and thus a long duration of the Fluidför dereinrichtung, especially the main pump realized.

This is achieved according fiction, with a fluid conveying device with the features of claim 1. It is envisaged that the forepump has a coupled with the pre-pump input shaft Vorpumpenantriebsrad and cooperating with the Vorpumpenantriebsrad for fluid delivery acting Vorpumpenförderrad, wherein the backing pump and the main pump are drivingly coupled to a common drive shaft, and wherein the Vorpum penförderrad and the main pump input shaft via a connecting shaft are connected to each other ver, so that the pre-pump input shaft is coupled directly and the main pump input shaft via the connection shaft to the drive shaft.

The fluid delivery device serves to convey a fluid, for example a liquid or a gas. For this purpose, the fluid delivery device has the backing pump and the main pump, wherein the main pump is fluidly connected to the backing pump. That means, that the fluid is first supplied to the backing pump, which promotes the fluid pump in the direction of the main. The funded by the forepumping fluid is thus made available to the main pump, which further promotes the fluid, namely, for example, in the direction of a Fluidaus lasses the fluid conveyor, which can also be referred to as conveyor Fluid outlet.

Each of the pumps has an input shaft through which it is driven, namely the backing pump via the Vorpumpeneingangs wave and the main pump via the Hauptpumpenein input shaft. The fore pump also has two wheels for fluid delivery, namely the Vorpum penantriebsrad and the Vorpumpenförderrad on. The Vorpumpenantriebsrad and the Vorpum penförderrad are provided for fluid delivery and designed for this reason so that they cooperate in a rotational movement of the Vorpumpeneingangs wave for conveying the fluid and in this case, for example, interlock.

The pre-pump drive wheel is coupled to the pre-pump input shaft, preferably rigid and / or permanent. The Vorpumpenantriebsrad is preferably arranged on the Vorpumpenein input shaft so that it always has the same speed during operation of the backing pump as the Vorpumpeneingangs wave. The pre-pump input shaft is drivingly coupled to the common seed drive shaft, preferably in turn rigid and / or by manent. For example, the pre-pump input shaft and the common drive shaft are designed in one piece, so that the pre-pump input shaft is formed by the drive shaft and / or vice versa. In that regard, the backing pump via the drive shaft is directly and directly driven.

The main pump, however, should only be driven indirectly via the drive shaft. For this purpose, the main pump is drivingly connected via the backing pump to the drive shaft, so that upon a rotational movement of the drive shaft, the main pump via the forepump on is driven ben. For this purpose, the Vorpumpenantriebsrad and the Vorpumpenförderrad are drivingly connected to each other. This is to be understood that the Vorpumpenantriebsrad provided for driving the Vorpumpenförderrad and is configured so that in a Drehbewe movement of the Vorpumpeneingangswelle there is a rotational movement of both the Vorpumpenantriebsrads and the Vorpumpenförderrads.

The Vorpumpenförderrad is now verbun with the main pump input shaft drive technology, namely on the connection shaft. In other words, the main pump is pump-driven drive-technically connected, so that there is preferably a rotational movement of the main pump input shaft during a rotational movement of the Vorpumpenförderrads. The main pump input shaft and the connection shaft can be configured separately or integrally with each other. In the latter case, the main pump input shaft forms the connec tion shaft and / or vice versa. For example, therefore, the Vorpumpenförderrad by means of the connection shaft and / or the main pump input shaft is rotatably mounted.

In other words, the fluid delivery device is designed such that the Vorpumpenein input shaft is directly and directly coupled to the drive shaft. The Hauptpumpenein input shaft, however, is only indirectly via the connection shaft and / or the backing pump coupled to the drive shaft. Such an embodiment of the fluid delivery device has the advantage that the speed of the backing pump and the main pump or the respec conditions input shaft in a fixed relationship with each other, so that, for example, between the speeds, a certain ratio exists. As a result, a very good coordination between the backing pump and the main pump is achieved during operation of the fluid delivery device.

A further embodiment of the invention provides that form the Vorpumpenantriebsrad and Vorpumpenförderrad a transmission gear for the main pump with a certain gear ratio. In other words, the specific ratio ratio between the Vorpumpenantriebsrad and the Vorpumpenförderrad before and therefore also between the Vorpumpeneingangswelle and / or the drive shaft on the one hand and the connec tion shaft and / or main pump input shaft on the other.

The gear ratio is preferably different from one, so that due to the transmission gear during operation of the fluid delivery Vorpumpenförderrad has a speed which is different from a speed of the Vorpumpenantriebsrads or between the speed of the Vorpumpenförderrads and the speed of the Before pumpenantriebsrads a certain speed ratio is present corresponds to the translation ratio.

With the aid of the forepump, the speed of the drive shaft for the main pump is adapted in this respect. In this way, each opti male speed can be realized for both the fore pump and for the main pump, without having to provide an additional gear, wel Ches connected to the pre-pump input shaft and the main pump input shaft are. In other words, by driving the main pump via the backing pump, a particularly compact design of the fluid delivery device is realized.

In the context of a further embodiment of the invention, it is provided that the backing pump is designed as a gear pump and / or the main pump as a rotary piston pump. The design of the backing pump as a gear pump allows a particularly advantageous and reliable use of the backing pump as a transmission gear. Under the gear pump, for example, an external gear pump or an internal gear pump is understood. Particularly preferably, the backing pump or the gear pump is gap-compensated. If the backing pump in the form of the gear pump, so the Vorpumpenantriebsrad can be referred to as a backing pump drive gear and the Vorpumpenförderrad as Vorpumpenförderzahnrad and are according to their name as gears before. The interaction of the gear wheels for fluid delivery is carried out by intermeshing or combing with each other. In other words, the Vorpumpenantriebszahnrad meshes with the backing pump conveyor gear for fluid delivery, at the same time the transmission gear is formed. A toothing of the Vorpumpenantriebszahnrads and a toothing of the Vorpumpenförder gear are preferably designed as helical gears. As a result, a Ge noise formation of the backing pump can be significantly reduced compared to a straight toothing. Of course, however, alternatively, the teeth may be formed as a straight toothings.

Additionally or alternatively, the main pump is present as a rotary piston pump. Under the Rota tion piston pump, for example, a rotary piston pump, a rotary vane pump, a rotary piston pump or a gear pump is understood. The gear pump can in turn be configured as external gear pump and as internal gear pump. The main pump is particularly preferably configured gap-compensated, namely in particular in the case of their staltung as a gear pump. Particularly preferably, the main pump is designed as a gear pump staltet, so for example as external gear pump or as internal gear pump, wherein last res in a particularly preferred embodiment of the fluid conveyor is the case. Particularly excellent properties of the fluid delivery device arise in the case of the design of the backing pump and the main pump as gear pumps, so that so both pumps are present as a gear pump. For example, the forepump is wheel pump as external tooth and the main pump designed as an internal gear pump. As a result, a FITS reliable supply of fluid for the main pump is realized by the backing pump. A particularly preferred embodiment of the invention provides that the backing pump has a larger delivery volume than the main pump. The delivery volume can also be referred to as displacement volume. For example, the delivery volume of the forepump is at least 5%, at least 10%, at least 15%, at least 20% or at least 25% greater than the delivery volume of the main pump. With such a configuration of the Fluidför dereinrichtung it is ensured that the main pump is always provided a sufficient amount of fluid from the backing pump. As a result, a particularly good degree of efficiency of the main pump and thus a good efficiency of the fluid conveyor is achieved.

A further embodiment of the invention provides that the main pump drive gear and a cooperating with the main pump drive gear for fluid delivery Hauptpumpenförderrad, the Vorpumpenförderrad and the Hauptpumpenan drive wheel are drivingly connected to the connection shaft. For the Hauptpumpenan drive wheel and the main pump impeller so far applies preferably the drive wheel for the Vorpumpenan and the Vorpumpenförderrad said. The Hauptpumpenantriebsrad also cooperates with the Hauptpumpenförderrad for fluid delivery, for example by meshing or combing with each other. In the case of designing the main pump as a gear pump, the main pump drive gear may be referred to as a main pump drive gear and the main pump feed wheel as a main pump feed gear.

The main pump drive gear is gekop pelted with the main pump input shaft, preferably rigid and / or permanent. For example, the Hauptpumpenantriebsrad sits on the main pump input shaft, so that during operation of the fluid conveyor, the speed of the Hauptpumpenantriebsrads the speed of the main pump input shaft speaks ent. The main pump drive gear and the main pump impeller cooperate for fluid delivery such that the main pump impeller is driven by the main pump drive wheel during operation of the fluid delivery device. In a rotary movement of the main pump drive wheel is so far a rotational movement of the Hauptpumpenförderrads ago, whereby a total of the fluid conveying effect is achieved.

For drive technology coupling of the main pump with the backing pump Vorpumpenför derrad and Hauptpumpenantriebsrad are drivingly connected to the connection shaft, namely preferably rigid and / or permanent. For this purpose, it is provided, for example, that the connection shaft is integrally formed with the main pump input shaft relation ship as these trains. Both the pre-pump and the wheel are preferred Main pump drive arranged on the connection shaft and drivingly connected to her. For example, the pre-pumping and the Hauptpumpenantriebsrad are rotatably mounted on the connection shaft. As a result, an additional storage of the Vorpum- penförderrads or the Hauptpumpenantriebsrads is avoided, so that the space required by the fluid conveyor is further reduced.

A preferred embodiment of the invention provides that the main pump as an internal gear pump, in particular as a sickle pump, is present, wherein the main pump drive gear as a pinion gear and the Hauptpumpenförderrad are configured as a ring gear. The internal gear pump is particularly preferably configured gap-compensated. The internal gear pump can piece without filling, so far pieceless, or be formed with filler. In the latter case, it is in the form of the sickle pump, in which the (crescent) filler between the pinion gear wheel and the ring gear is arranged so that the filler - seen in cross-section with respect to a rotational axis of the pinion gear and / or a rotation axis of the Hauptpumpenförderrads - with a in the radial direction inside on the inner pinion gear, in particular on teeth of the pinion gear, and with its radially outward side on the ring gear, in particular on teeth of the ring gear rests. The design of the main pump as an internal gear pump enables a particularly high efficiency of the fluid delivery device.

A further preferred embodiment of the invention provides that in the operative connection between the Vorpumpenförderrad and the main pump input shaft, a further translation gear is arranged. The further transmission gear thus occurs to the gear pump from the before and the Vorpumpenförderrad formed gear transmission so that the main pump via the transmission gear and the further transmission gear, which are connected in series with each other, is connected to the drive shaft. The further transmission gear is, for example, as a gear transmission, for example as a spur gear, ago. In particular, it is designed as a planetary gear or planetary gear.

The further transmission gear has a gear ratio, which is preferably different from one, so that between the rotational speed of the main pump input shaft and the speed of the Vorpumpenförderrads a certain speed ratio is present, which corresponds to the gear ratio of the further transmission gear. In the translation of the further transmission gear which differs from one, the rotational speeds of the pre-pump delivery wheel and the main pump input are variable during operation of the fluid delivery device. le different from each other. The use of the further transmission gear allows operation of both the fore pump and the main pump at a respective optimal speed.

A further embodiment of the invention provides that the forepump has a prime pump fluid inlet and a prime pump fluid outlet and the main pump has a main pump fluid outlet and a main pump fluid outlet, with a conveyor fluid inlet of the fluid conveyor to the prime pump fluid inlet, the prime pump fluid outlet to the main pump fluid inlet and the main pump fluid outlet to the conveyor fluid outlet Conveyor is fluidically connected. Thus, the fluid delivery device itself has the delivery fluid inlet and the delivery fluid outlet. Via the conveyor fluid inlet, the fluid is supplied to the fluid conveyor, and via the conveyor fluid outlet, it provides the fluid delivered by the forepump and the main pump. In other words, fluid is supplied to the fluid delivery device via the delivery fluid inlet and fluid is withdrawn via the delivery fluid outlet.

The forepump has the fore pump fluid inlet and the fore pump fluid outlet. Fluid is supplied to the fore pump via the fore pump fluid inlet and the fluid conveyed by the fore pump is withdrawn via the fore pump fluid idauslass. The same applies to the main pump, which in this respect has the main pump fluid inlet and the main pump fluid idauslass. The main pump is provided with the fluid through the main pump fluid outlet which, after being conveyed through the main pump, is withdrawn through the main pump fluid outlet.

The fore pump and the main pump are fluidically connected in series. For this purpose, the Vorpumpenfluideinlass is fluidically connected to the conveyor fluid inlet, so that the backing pump is directly supplied to the fluid, which is the Fluidfördereinrich device supplied. The pre-pump fluid outlet is connected to the main pump inlet so that fluid supplied to the main pump is delivered by the pre-pump. The main pump fluid outlet, in turn, is fluidly connected to the conveyor fluid outlet so that the fluid conveyed by the fore pump and the main pump can be withdrawn via the conveyor fluid outlet of the fluid conveyor. A development of the invention provides that the Vorpumpenfluidauslass via a valve assembly, in particular a check valve, having bypass line is connected to the pump fluid inlet in front of fluidic. About the bypass line is a un indirect flow connection between the Vorpumpenfluideinlass and the Vorpumpenflu idauslass produced which does not extend beyond the backing pump itself. In this respect, fluid can flow back from the pre-pumping fluid outlet to the pre-pumping fluid inlet via the bypass line in order to bypass the backing pump. In the bypass line, the valve arrangement is arranged, by means of which the flow connection is adjustable. For example, in a first setting of the valve assembly, the flow communication between the pre-pump fluid outlet and the pre-pump fluid inlet via the bypass line is broken, whereas it is established at a second setting.

The valve arrangement is particularly preferably in the form of the check valve or has such at least. This is designed to allow flow from the pre-pump fluid outlet to the pre-pump fluid inlet, but inhibits reverse flow. For example, the check valve is configured to merely establish flow communication between the pre-pumping fluid outlet and the pre-pumping fluid in the direction of the pre-pumping fluid inlet when a pressure differential between the pre-pumping fluid outlet and the pre-pumping fluid inlet exceeds a certain pressure differential. By means of the bypass line and the valve arrangement present therein, a need-based supply of the main pump with fluid is ensured. In this case, the check valve acts in particular as a pressure relief valve, so that the input side of the main pump applied, caused by the forepump pressure is limited to a certain value be.

The bypass line and the check valve or pressure relief valve serve a demand-driven admission of the main pump with fluid. They are particularly necessary if the backing pump promotes more fluid in the direction of the main pump in at least one operating state than this can absorb. Particularly ideal is therefore an embodiment in which the bypass line and the valve assembly or the check valve fall ent and the backing pump is tuned to the main pump so that there is always an ideal Beauf suppression of the main pump with the fluid. For this purpose, the fore pump of the main pump provides exactly or at least almost exactly the amount of fluid that can absorb this, in particular at exact a speed of the drive shaft, at least one rotational speed of the drive shaft or a plurality of different rotational speeds of the drive shaft, particularly preferably over a nominal rotational speed range of the drive shaft, which occurs or at least can occur during normal operation of the fluid delivery device.

Finally, in the context of another preferred embodiment of the invention, it can be ensured that the backing pump and the main pump are arranged in a common pump housing. The two pumps, so the backing pump and the main pump, are therefore not available in different cases, but are rather integrated in the Fluidförderein direction taken together. In particular, both the Vorpumpenantriebsrad and the front pump impeller of the backing pump and the main pump drive and the main pump are the delivery of the main pump in or on the common pump housing rotatably mounted. This results in a particularly compact design of the fluid delivery device.

The invention will be explained in more detail with reference to the Ausführungsbeispie le shown in the drawing, without any limitation of the invention. Showing:

1 shows a schematic representation of a fluid delivery device with a fore pump and a main pump in a first view,

Figure 2 is a schematic representation of the fluid conveying device in a second view, as well

Figure 3 is a schematic sectional view through the fluid conveying device, wherein the

Vorpumpe and the main pump in a common pump housing vorlie conditions.

FIG. 1 shows a schematic representation of a fluid delivery device 1, which has a pre-pump 2 and a main pump 3. The fore pump 2 has a pre-pumping fluid inlet 4, which is fluidically connected to a delivery fluid inlet 5. A pre-pumping fluid outlet 6 of the fore-pump 2 is connected to a main pump fluid inlet 7 in a flow-engineering manner. In turn, a main pump fluid outlet 8 of the main pump 3 is fluidically connected to a delivery fluid outlet 9 of the fluid delivery device 1. Finally, therefore, the fore pump 2 and the main pump 3 Strömungstech nisch in series between the conveyor fluid inlet 5 and the Fördereinrich tungsfluidauslass 9 before. It can be seen that the pre-pumping fluid outlet 6 and the pre-pumping fluid outlet 6 penfluideinlass 4 are fluidically connected to one another via a bypass line 10. In the bypass line 10, a valve assembly 11 is provided, which has a check valve 12 or configured as such.

The backing pump 2 is driven via a pre-pump input shaft 13 and the main pump 3 via a main pump input shaft 14. The fore pump 2 and the main pump 3 are connected to a common drive shaft 15 to drive technology. In other words, the pre-pump input shaft 13 and the main pump input shaft 14 are both drivingly connected to the drive shaft 15. In the case of the pre-pump input shaft 13 is a direct connection. For example, the pre-pump input shaft 13 is formed integrally with the drive shaft 15 to. The main pump input shaft 14, however, is drivingly connected via the backing pump 2 to the drive shaft 15. To this end, a Vorpumpenantriebs form wheel 16 and a Vorpumpenförderrad 17 of the backing pump 2, a transmission gear 18 for the main pump 3 from.

The Vorpumpenantriebsrad 16 is coupled to the Vorpumpeneingangs wave 13, preferably it sits on this and is rigidly and / or permanently connected to it. The Vorpumpenförderrad 17, however, during an operation of the fluid conveyor 1, ie in a Drehbewe movement of the drive shaft 15 is driven by the Vorpumpenantriebsrad 16 at. In the illustrated here Darge embodiment, the fore-pump 2 is as a gear pump, namely as external tooth wheel before. The Vorpumpenantriebsrad 16 and the Vorpumpenförderrad 17 are so far as gears, which mesh with each other to form the transmission gear 18. In addition, the Vorpumpenantriebsrad 16 and the Vorpumpenförderrad 17 to Fluidförde tion together.

Similarly, the main pump 3 has a main pump drive wheel 19 and a main pump impeller 20. These also act to provide a fluid conveying action of the main pump 3 together. For driving technology connecting the main pump 3 with the fore pump 2, a connection shaft 21 is provided, which connects the Vorpumpenförderrad 17 and the main pump input shaft 14 and thus the main pump drive 19 with each other. In that regard, it is clear that the pre-pump input shaft 13 is coupled directly to the drive shaft 15, whereas the main pump input shaft 14 only indirectly via the Ver connecting shaft 21 and the backing pump 2 is drivingly coupled to the drive shaft 15, so driven via the backing pump 2 of the drive shaft 15 becomes. Particularly advantageous is an embodiment of the fluid delivery device 1, in which both the backing pump 2 and the main pump 3 is designed as a gear pump. In the embodiment shown here, the fore-pump 2 is in the form of an external gear pump and the main pump 3 is in the form of an internal gear pump. Here, the main pump drive gear 19 is a pinion gear 22 and the main pump impeller 20 is a ring gear 23 of the internal gear pump. The pinion gear 22 and the ring gear 23 are rotatably mounted about mutually parallel offset Drehach sen. The pinion gear 2 has seen in cross section on outer dimensions which are smaller than the inner dimensions of the ring gear 23, so that only part of a serration of the pinion gear 22 meshes with a toothing of the ring gear 23. The internal gear wheel pump is designed as a sickle pump, so that between the pinion gear 22 and the hollow wheel 23 in regions a sickle-shaped filler 24 is arranged. Preferably, either the backing pump 2 or the main pump 3 are formed gap-compensated. In particular, an embodiment is preferred in which the main pump 3, but not the backing pump 2, gap is compensated. The backing pump 2 is in this respect before gap compensation. However, it is also possible for both the backing pump 2 and the main pump 3 to be gap-compensated.

FIG. 2 shows a further schematic illustration of the fluid delivery device 1. It can be recognized that the backing pump 2 or the pre-pump drive wheel 16 and the pre-pumping pin wheel 17 each have a helical toothing. As a result, the smoothness of the backing pump 2 is significantly improved. With regard to the further embodiment of the Fluidfördereinrich device 1 reference is made to the above statements.

FIG. 3 shows a further schematic representation of the fluid delivery device 1. Again, reference is made in full to the above statements. In addition, it is now clear that the fore pump 2 and the main pump 3 are arranged in a common pump housing 25 at. Here, the Vorpumpenantriebsrad 16, Vorpumpenför the derrad 17, the Hauptpumpenantriebsrad 19 and the Hauptpumpenförderrad 20 are rotatably supported in and / or on the pump housing 25 preferably. A flow direction of the fluid through the idfördereinrichtung Flu 1 is indicated by the arrows 26.

The fluid delivery device 1 shown here has excellent delivery properties for the fluid with a long service life, because the fore pump 2 and the main pump 3 are ideally matched to each other, namely by means of the transmission gear 18th

Claims

1. fluid conveying device (1) with a fore pump (2) and a fluidically connected to the fore pump (2) main pump (3), the forepump (2) via a Vorpum peneingangswelle (13) and the main pump (3) via a main pump input shaft ( 14) are driven, characterized in that the fore pump (2) via a pump with the Vorpumpenein (13) coupled Vorpumpenantriebsrad (16) and one with the Vorpumpenantriebs wheel (16) for fluid conveying cooperating Vorpumpenförderrad (17), wherein the Vorpumpe (2) and the main pump (3) with a common drive shaft (15) are driving tecnically coupled, and wherein the Vorpumpenförderrad (17) and the main pump input shaft (14) via a connection shaft (21) are interconnected, so that the Vorpum Peneingangswelle (13) directly and the main pump input shaft (14) via the connecting shaft (21) with the drive shaft (15) is coupled.

2. fluid delivery device according to claim 1, characterized in that the Vorpumpenan drive wheel (16) and the Vorpumpenförderrad (17) form a transmission gear (18) for the main pump (3) with a certain gear ratio.

3. fluid delivery device according to one of the preceding claims, characterized in that the fore pump (2) as a gear pump and / or the main pump (3) is designed as Rotationskol benpumpe.

4. fluid delivery device according to one of the preceding claims, characterized in that the fore pump (2) has a larger delivery volume than the main pump (3).

5. Fluid delivery device according to one of the preceding claims, characterized in that the main pump (3) has a Hauptpumpenantriebsrad (19) and a drive pump with the main pump (19) for fluid delivery cooperating Hauptpumpenförderrad (20), wherein the Vorpumpenförderrad (17) and the Hauptpumpenantriebsrad (19) are drivingly connected to the connection shaft (21).

6. fluid delivery device according to one of the preceding claims, characterized in that the main pump (3) as an internal gear pump, in particular as sickle pump, is present, wherein the Hauptpumpenantriebsrad (19) designed as a pinion gear (22) and the Hauptpumpenförderrad (20) as a ring gear (23) are.

7. fluid delivery device according to one of the preceding claims, characterized in that in the operative connection between the Vorpumpenförderrad (17) and the Hauptpum peneingangswelle (14), a further transmission gear is arranged.

8. fluid delivery device according to one of the preceding claims, characterized in that the fore pump (2) a Vorpumpenfluideinlass (4) and a Vorpumpenfluidauslass (6) and the main pump (3) has a main pump fluid inlet (7) and a Hauptpumpenfluideinlass (8), wherein a conveyor fluid inlet (5) of the fluid conveyor (1) is fluidly connected to the prime pump fluid inlet (4), the prime pump fluid outlet (6) is connected to the main pump fluid inlet (7) and the main pump fluid outlet (8) is fluidly connected to the conveyor fluid outlet (9) of the fluid conveyor (1).

9. fluid delivery device according to one of the preceding claims, characterized in that the Vorpumpenfluidauslass (6) via a valve assembly (11), in particular a check valve (12), comprising bypass line (10) to the Vorpumpenfluideinlass (4) is connected by flow technology.

10. Fluid delivery device according to one of the preceding claims, characterized marked, that the fore pump (2) and the main pump (3) in a common pump housing (25) are arranged.