DE20022423U1 - pump - Google Patents

Description

Ullrich &''MäüM'änVI 1

Industrial property rights· Intellectual Property

4220/G/035 Heidelberg, June 1, 2001/ph

Utility model application

of the company concerning a LuK

Vehicle Hydraulics GmbH & Co. KG
Georg-Schaeffler-Strasse 3

61352 Bad Homburg

"Pump"

Representative Office Spain Luisenstraße 14

,•E _t -oe/2Q"Beriissß, jfilicaQte. ···; Di69ai AHeidelberg : G/ünäalucjä, M(S) -ASS. _# . * _# '. Telephone +49 62 21/60 43-0 ·. .*·..· .:...:.. : .:..*..' fe1efa)C4496221/6043-60

e-mail: un@hd-patent.de

The invention relates to a pump for conveying a fluid, in particular a vane pump, with a conveying device accommodated in a housing, a supply channel for the fluid formed in the housing, which extends into the suction area of the conveying device and opens into a jet chamber upstream of the conveying device, and with an injector device which serves to convey the fluid, jets into the jet chamber with a jet nozzle and injects fluid under high pressure into the fluid emerging from the supply channel into the jet chamber, thereby entraining or accelerating it, wherein the jet chamber is fluidly connected to at least two suction kidneys of the conveying device via a suction channel.

Pumps of the type in question here, such as vane pumps, are well known in practice. Reference is made to DE 39 28 029 A1, DE 41 22 433 C2 and DE 41 38 516 A1 merely as examples.

Pumps of this generic type are used, for example, in power steering systems and pump a special oil to assist the steering force applied to the steering wheel of a motor vehicle. These are preferably vane pumps that suck in oil from a reservoir provided outside the pump, for example from an external tank. Such pumps are usually equipped with a flow control valve through which oil can be fed from the high-pressure area - pressure side - into the intake area - suction side - of the pump. From a certain pump speed and with a fixed adjustable delivery rate, the flow control valve opens an outflow hole through which oil under high pressure can escape. The oil reaches the intake area of the delivery device.

A pump of this type is already known from DE 41 38 516 A1, which has a very special conveying measure for conveying the tank oil in order to achieve operation that is as free of cavitation as possible, namely an injector device that works similarly to a water jet pump. The injector device is supplied with fluid flowing at high speed, which is fed to the injector device from the high-pressure area, preferably via a flow control valve. This fluid flowing at high speed injects the injector inlet

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direction into the fluid flowing from the supply channel, in the area of a jet chamber located upstream of the conveying device. As a result, the fluid coming from the tank is entrained or accelerated and from there reaches the suction area of the conveying device via another channel system.

However, the technology known from DE 41 38 516 A1 concerning the use of an injector device is problematic in that this injector device only acts on one side of the housing with a jet nozzle and from there must convey the fluid coming from the tank to both sides of the housing - into the respective suction area - in order to make the fluid available in sufficient quantities on both sides of the housing at the suction kidneys assigned to both sides of the conveying device or the rotation group.

The main problem underlying the state of the art is that the valve jet, which preferably flows into the jet nozzle in front of the valve piston under possibly high pressure on the valve piston at high speed, basically runs obliquely and therefore symmetrically designed channels are unsuitable.

Due to the usually different jet impact on the suction kidneys arranged on both sides, different pressure conditions occur in the fluid, which in turn leads to a different loading of the suction kidneys on both sides. This leads to cavitation or damage caused by cavitation, particularly when the pump has a high delivery rate. In addition, the uniform filling of the suction areas on both sides is questionable.

In any case, the current state of the art does not guarantee that the suction kidneys or suction chambers are filled evenly. On the contrary, different pressure conditions and flow speeds of the fluid in front of the suction kidneys lead to different filling, which in turn causes the problems mentioned above - cavitation and thus noise in the pump.

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The present invention is therefore based on the object of designing and developing a pump of the generic type in such a way that cavitations and thus noises occurring in the pump are largely avoided by simple design means.

The pump according to the invention solves the above problem by the features of patent claim 1. According to this, a pump of the type mentioned at the outset is characterized in that in the inflow area of the jet chamber and/or in the suction channel, means are provided which influence the flow of the fluid and ensure an at least largely equal volume flow into the suction kidneys.

According to the invention, it was first recognized that the cavitations or noises in the pump that occur in the prior art are due to the varying degrees of filling of the suction chambers or suction kidneys of the conveying device. This already required an in-depth technical analysis, particularly with regard to the jet direction, whereby such an analysis is inventive in itself. In a next step, it was recognized that the problems that occur in the prior art can be eliminated by ensuring at least a largely equal volume flow into the suction kidneys. Finally, it was recognized that this does not require modifying the jet nozzle or influencing the pressure of the fluid to be injected via the jet nozzle - in any way - but rather providing the fluid exiting into the jet chamber with means that influence the flow of the fluid in the inflow area of the jet chamber and/or in the suction channel, so that - distributed between the suction kidneys - an at least largely equal volume flow into the suction kidneys inevitably results. Ultimately, according to the invention, the flow path up to the suction kidneys is designed in such a way that the entire volume flow is divided into equal partial flows up to the suction kidneys. The means in the flow path that influence the flow of the fluid are responsible for such an equal or at least largely equal division of the volume flow, whereby these means can be integral components of the flow path and thus of the housing. In this respect, it should be noted that the pressure of the fluid injected via the jet nozzle results from the external forces at the edges or edge areas and constantly changes throughout the flow.

Now, within the scope of a simple embodiment of the pump according to the invention, it can be a construction that only radiates into a single jet chamber on one side, with this single jet chamber being fluidly connected to two or more suction kidneys of the conveying device via a suction channel. However, it is also conceivable that the supply channel opens into a jet chamber upstream of the conveying device on both sides with a sub-channel and that the injector device radiates into each of the two jet chambers on both sides with a jet nozzle. Both jet chambers are fluidly connected to at least two suction kidneys of the conveying device via a suction channel or corresponding sub-channels. Means that influence the flow of the fluid are then provided on both sides, which ensure at least largely the same volume flow into the suction kidneys on both sides.

In a further way according to the invention, it has been recognized that the jet of fluid directed into the respective jet chamber can be directed obliquely in the direction of flow onto the wall of the jet chamber opposite the jet nozzle and hits it at a corresponding angle. The angle of the jet is also influenced in such a way that its kinetic energy can be optimally used to evenly fill the suction kidneys. In particular, turbulence and jet erosion should be avoided.

To further promote optimal flow of the fluid immediately after it emerges from the injector or jet nozzle, it is also advantageous if a ski jump-like guide device is formed in the impact area of the wall, which is roughly adapted to the jet angle of the fluid or is coordinated with it. To avoid damaging turbulence, the fluid is properly collected and directed by means of the ski jump-like guide device, and this with the lowest possible loss of kinetic energy.

In a further advantageous manner, the impact area or the ski jump-like guide device in the blasting chamber is initially provided with a

This cross-sectional tapering of the flow path is arranged downstream. This cross-sectional tapering and thus bundling of the flow leads to an acceleration of the flow due to the resulting nozzle effect. This cross-sectional tapering could in turn be followed by a deflection and finally a division into the two suction channels, whereby the change in direction imposed by the deflection influences the subsequent division of the flow into the two suction channels. In the area of the division, guide devices can again be provided, which can be assigned to the respective walls of the flow path or the suction channels, for example. The deflection and division of the entire flow must in any case be carried out in such a way that approximately the same volume flow results in the two suction channels, which in turn reaches the inlet of the suction kidneys via the two suction channels.

In concrete terms, the blasting chamber could be fluidically connected via two separate suction channels, each with at least one suction kidney or suction chamber. In other words, the blasting chamber is divided into two independent suction channels, which in turn fluidically connect the blasting chamber with the suction kidneys. Regardless of the length of the suction channels and regardless of the course of the respective suction channel, the means influencing the flow are designed in such a way that a largely equal volume flow results to the two suction kidneys - via the respective suction channels. The means influencing the flow of the fluid are responsible for this, for example the ski jump-like guide device provided in the blasting chamber and in particular the targeted coordination of the formation of walls, "noses" or the like. Corresponding devices are also conceivable in the suction channels.

As already mentioned, the flow from the jet chamber into the two suction channels can be influenced by the design of the flow path. In this way, the flow into the two suction channels is diverted at least slightly. This diversion serves to influence the volume flow directed into the suction channels, so that the flow is divided into the two suction channels in such a way that the volume flow is evened out.

In accordance with the other general conditions regarding the design of the suction channels, these could be asymmetrical and of different lengths.

In the suction channels and/or immediately in front of the suction kidneys, further means for influencing the flow, in particular cross-sectional modifications and/or guide devices, can be provided in order to have a final influence on the volume flow entering the suction kidneys. This is where the already divided volume flow can be fine-tuned. Cross-sectional tapering, further deflections or even a labyrinth-like design of the suction channel are adequate means for influencing the flow, or more precisely the flow speed, the pressure prevailing there and thus the volume flow.

As part of an alternative design of the flow path from the jet chamber to the suction kidneys, the jet chamber could be flow-connected to at least two suction kidneys arranged one behind the other in a single suction channel. In this respect, too, the inflow area previously referred to as the impact area or the ski jump-like guide device could initially be followed by a cross-sectional tapering of the flow path that serves to concentrate the flow, whereby the flow cross-section can decrease steadily, curved or even in stages towards the first suction kidney. The concentration of the flow leads to an acceleration of the fluid up to the first suction kidney.

Furthermore, it is possible that further means influencing the flow, in particular guide devices, are provided in the suction channel, in particular immediately in front of the suction kidneys. Immediately in front of the suction kidneys - as in the impact area in the blasting chamber - there could be ski jump-like guide devices that guide the flow into the suction kidneys while avoiding turbulence and without causing significant flow losses. The guide devices - both at any point in the suction channel and immediately in front of the suction kidneys - are preferably designed as integral components of the housing.

In a further advantageous manner, the flow cross-section between the first suction kidney and the second suction kidney is at least equal to the flow cross-section in front of the

first suction kidney. It must be ensured that the volume flows into the two suction kidneys are at least largely evenly distributed so that the suction kidneys are evenly loaded. A deflection-causing baffle could be formed behind the second suction kidney, so that a deflection and thus a further influence of the volume flow into the second suction kidney takes place. In any case, the suction channel could end immediately behind the second suction kidney with the deflection wall provided there.

In a further embodiment, the suction channel in the area between the two suction kidneys or after the suction kidney furthest back in the flow direction could be connected to the jet chamber or to the area of the suction channel in front of the first suction kidney, either directly or via a bypass. Such a flow connection can influence the pressure conditions and thus also the volume flows in front of the respective suction kidneys, so that a balance can also be made in relation to the volume flows.

In addition to the course of the suction channel and the provision of various guide devices, the flow of the fluid, in particular the volume flow directed into the suction kidneys, can be influenced by further measures, namely by modifying the inner wall of the jet chamber and/or the suction channel or channels. In this respect, the surfaces could have structures and/or coatings that influence the flow. In concrete terms, the inner walls could be surface-treated - depending on requirements - whereby roughening the surface leads to an increase in flow resistance and smoothing or a smooth coating of the surface leads to a reduction in flow resistance and thus to an acceleration of the flow.

Finally, it should be noted that the housing can be closed on one side by a front housing cover and on the other side, if necessary, by a bearing flange. In this respect, it is possible that the jet chamber formed on both sides of the conveyor device is at least largely incorporated into the housing cover and, if necessary, into the bearing flange. In addition, it is conceivable that the flow paths formed on both sides of the actual housing are identical or different, depending on the

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the housing or the housing cover and/or the bearing flange specified geometries and requirements.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, reference is made on the one hand to the claims subordinate to claim 1 and on the other hand to the following explanation of two embodiments of the invention with reference to the drawing. In connection with the explanation of the preferred embodiments of the invention with reference to the drawing, generally preferred embodiments and developments of the teaching are also explained. The drawing shows

Fig. 1 in a schematic side view, sectioned, an embodiment of a generic pump,

Fig. 2 in a schematic side view, cut and enlarged, the

Object from Fig. 1 without housing cover, without bearing flange and without conveyor device,

Fig. 3 shows a schematic internal view of a bearing flange with two

suction channels,

Fig. 4 the object from Fig. 3 in a sectional view along

line A-A,

Fig. 5 the object of Fig. 3, partially, in a sectional view along the line B-B,

Fig. 6 the object of Fig. 3, partially, in a sectional view along the arcuate line C-C and

Fig. 7 shows a schematic interior view of a housing cover in which

Wall of a singular suction channel is formed.

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·

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Hg. 1 shows a simplified representation of a generic pump in a sectional side view, which in concrete terms is a vane pump with a rotation group 1 or conveying device not described in detail here. With regard to the special design of such a rotation group 1, reference is made to DE 41 38 516 A1 merely as an example.

The pump shown here comprises - as essential components - a housing 2 and a conveying device housed in the housing 2, which is the rotary group 1 already mentioned. On the front side, on one side, there is a housing cover 3 that closes off the housing 2 and on the other side, on the side opposite the housing cover 3, there is a bearing flange 4 that adjoins the housing 2. The actual housing 2 together with the housing cover 3 and the bearing flange 4 could be referred to as the housing in the broadest sense.

An outward-acting seal 5, 6 is arranged between the housing 2 and the housing cover 3 on the one hand and between the housing 2 and the bearing flange 4 on the other hand, wherein the seal 5 acting opposite the housing cover 3 is inserted in a groove 8 formed in the front face 7 of the housing 2. On the other side of the housing 2, the seal 6 is assigned to the bearing flange 4 or inserted in a groove 9 machined into the bearing flange 4. The groove 9 could also be machined into the front face 10 of the housing 2.

From the state of the art, it is already known - in itself - to provide a leakage path for the fluid between the pressure area 11 and the suction area 12 of the pump, namely a leakage path for leakage oil occurring on the pressure side and to be pumped to the suction side 12.

Fig. 1 and 2 clearly show that a supply channel 13 for the fluid extends into the intake area, i.e. towards the suction area 12. Furthermore, an injector device is provided for conveying the fluid, which works similarly to a water jet pump. This injector device 14 injects fluid under high pressure onto the control edge of the valve piston in front of a flow control valve piston.

at high speed into a jet chamber 15 upstream of the conveying devices 1, and there into the fluid exiting from the feed channel 13 and thereby accelerates the fluid or entrains the fluid.

The feed channel 13 opens into a separate jet chamber 15 on both sides of the conveyor device 1, each with a sub-channel 16, with the injector device 14 radiating from two sides, so that a jet nozzle 17 of the injector device 14 is directed into each of the two jet chambers 15. The jet nozzles 17 can be shortened or omitted if necessary in order not to obstruct the jet.

Fig. 1 and 2 together show that the injector device 14 is arranged centrally above the conveyor device 1. The jet nozzles 17 are aligned in such a way that the fluid injected at high speed via the jet nozzle 17 hits the fluid to be accelerated approximately in the direction of its flow, so that acceleration of the fluid coming from the tank is again promoted. The fluid from the system reaches the two jet nozzles 17 via the supply channel 13, the fluid from the pump reaches the two jet nozzles 17 via a valve bore 14 and discharge bores 14a.

Fig. 1 also shows that the blasting chamber 15 formed on both sides of the conveyor device 1 is largely incorporated into the housing cover 3 on one side and into the bearing flange 4 on the other side. The blasting nozzles 17 are directed orthogonally towards the wall 18 of the housing cover 3 opposite the outlet of the feed channel 13 on one side and towards the wall 19 of the bearing flange 4 opposite the outlet of the feed channel 13 on the other side, but can also be directed obliquely towards the wall 18 of the housing cover 3 opposite the outlet of the feed channel 13 on one side and towards the wall 19 of the bearing flange 4 opposite the outlet of the feed channel 13 on the other side, in order to effectively prevent turbulence.

According to the illustration in Fig. 3, means influencing the flow of the fluid are provided in the inflow area of the jet chamber 15 and in the suction channel 20, which ensure an at least largely equal volume flow into the

• ·* ·♦«

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ensure suction. The same applies to the second embodiment shown in Fig. 7.

Fig. 2 and 3 also show that the supply channel 13 opens into a blasting chamber 15 upstream of the conveying device 1 on both sides of the conveying device 1 with a sub-channel 16 and that the injector device 14 blasts into each of the two blasting chambers 15 on both sides with a blasting nozzle 17.

After exiting the valve piston at the outflow holes 14a, the jet directed into the jet chamber 15 is directed obliquely in the direction of flow onto the wall of the jet chamber 15 opposite the jet nozzle 17. The oblique orientation of the jet is symbolically indicated in Figs. 3 and 7 by an arrow 21. In any case, it is essential that the jet 21 directed into the jet chamber 15 strikes the wall 18 or 19 of the jet chamber 15 obliquely.

In Fig. 3, 4 and 7 - according to the embodiments shown - it is indicated that a ski jump-like guide device 22 is formed in the impact area of the jet 21. In this respect, the jet 21 hits the guide device 22 and is passed on there in the direction of the suction channel 20 without the formation of turbulence.

In the embodiment shown in Fig. 3, the jet chamber 15 is fluidically connected via two suction channels 20 to a suction kidney or suction chamber of the conveying device 1 (not shown in the figures). Fig. 3 also shows that the flow from the jet chamber 15 into the two suction channels 20 is diverted by the design of the flow path, the diversion of the flow serving to influence the volume flow directed into the suction channels 20.

Specifically, the two suction channels 20 on both sides of the jet chamber 15 are essentially symmetrical. A cross-sectional taper 24 of the flow path, which serves to concentrate the flow, is arranged downstream of the impact area in the jet chamber 15. The cross-sectional taper 24 is followed by a deflection 23 and division 25 into the two suction channels 20, whereby the formation of opposing noses 24a, 24b is of particular importance.

Fig. 3 further shows that further means for influencing the flow are provided in the suction channels 20 and immediately in front of the suction kidneys, namely cross-sectional modifications and guide devices 20.

Fig. 4, 5 and 6 show cross sections through the object from Fig. 3. Fig. 4 shows in particular the ski jump-like guide device 22 formed in the blasting chamber 15, by means of which the jet 21 is deflected or guided without the creation of unnecessary turbulence.

Fig. 5 shows a cross-section of the suction channel 20 in the area of the suction kidney, also with a corresponding guide device 26, which is an integral part of the wall. The situation is similar with the illustration in Fig. 6, which shows the suction channel 20 approximately in longitudinal section. In this illustration, a guide device 26 can also be seen in the wall of the suction channel 20, namely at the end of the suction channel 20. This guide device 26 also promotes the flow into the suction kidney.

The further embodiment of the inventive design of a suction channel shown in Fig. 7 relates to a housing cover 3, in which at least a part of the jet chamber 15 and a singular suction channel 20 are incorporated. Here too, the jet 21 hits a ski jump-like guide device 22, whereby the jet 21 is influenced in its flow direction.

In any case, Fig. 7 shows particularly clearly that the jet chamber 15 is fluidically connected via a single suction channel 20 to two suction kidneys arranged one behind the other, not shown in the figures, wherein only the inlets 27 directed towards the suction kidneys are indicated there.

A cross-sectional tapering 24 of the flow path or suction channel 20, which serves to concentrate the flow, is arranged downstream of the impact area or the ski jump-like guide device 22 in the jet chamber 15. Fig. 7 also shows that the flow cross-section to the first suction kidney or to its inlet 27 is constantly reduced, which causes the flow to accelerate. In the suction channel 20, in the embodiment chosen here immediately in front of the inlet 27 to the suction kidneys, there are further flow-influencing

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Means are provided, which are further guide devices 28. Immediately in front of the suction kidneys, ski jump-like guide devices 28 are also formed in order to facilitate the introduction into the inlet 27. The guide devices 28 are integral components of the housing cover 3.

In Fig. 7 it is further indicated that the flow cross-section between the first suction kidney and the second suction kidney is smaller (for example due to a flatter groove) than the flow cross-section in front of the first suction kidney or in front of its inlet 27. Furthermore, the flow cross-section between the first suction kidney and the second suction kidney or between the two inlets 27 is reduced at least slightly.

At the end of the suction channel 20, more precisely behind the second suction kidney or behind its inlet 27, a deflection-causing baffle 29 is formed, which again promotes the flow into the second suction kidney or into its inlet 27.

The patent claims submitted with the application are suggested formulations without prejudice to the attainment of further patent protection. The applicant reserves the right to claim further combinations of features previously only disclosed in the description and/or the drawings.

References used in subclaims indicate the further development of the subject matter of the main claim through the features of the respective subclaim. They are not to be understood as a waiver of the achievement of independent, objective protection for the combination of features of the referenced subclaims.

Since the subject matter of the subclaims may constitute separate and independent inventions in view of the state of the art on the priority date, the applicant reserves the right to make them the subject matter of independent claims or declarations of division. They may also contain independent inventions which have a design independent of the subject matter of the preceding subclaims.

The embodiments are not to be understood as a limitation of the invention. Rather, numerous changes and modifications are possible within the scope of the present disclosure, in particular those variants, elements and combinations and/or features which, for example, can be derived by the person skilled in the art with regard to solving the problem by combining or modifying individual features or elements or method steps described in the general description and embodiments as well as the claims and contained in the drawings, and which, through combined features, lead to a new object or to new method steps or method step sequences, including insofar as they relate to manufacturing, testing and working methods.

Claims (24)

1. Pump for conveying a fluid, in particular a vane pump, with a conveying device ( 1 ) housed in a housing ( 2 ), a supply channel ( 13 ) for the fluid formed in the housing ( 2 ), which is connected to the suction area of the conveying device ( 1 ) and opens into a jet chamber ( 15 ) upstream of the conveying device ( 1 ), and with an injector device ( 14 ) which serves to convey the fluid, jets into at least one jet chamber ( 15 ) with a jet nozzle ( 17 ) and injects fluid flowing at high speed into the fluid emerging from the supply channel ( 13 ) into the jet chamber ( 15 ) and thereby entrains or accelerates it, wherein the jet chamber ( 15 ) is fluidly connected to at least two suction kidneys of the conveying device ( 1 ) via at least one suction channel ( 20 ), characterized in that in the inflow region of the jet chamber ( 15 ) and/or in the suction channel ( 20 ) means are provided which influence the flow of the fluid and ensure an at least largely equal volume flow into the suction kidneys. 2. Pump, in particular according to claim 1, characterized in that the supply channel ( 13 ) opens on both sides of the conveying device ( 1 ) with a respective partial channel ( 16 ) into a respective jet chamber ( 15 ) arranged upstream of the conveying device ( 1 ) and that the injector device ( 14 ) radiates on both sides with a respective jet nozzle ( 17 ) into each of the two jet chambers ( 15 ). 3. Pump, in particular according to claim 1 or 2, characterized in that the jet directed into the jet chamber ( 15 ) impinges obliquely in the flow direction on the wall of the jet chamber ( 15 ) opposite the jet nozzle ( 17 ). 4. Pump, in particular according to one of claims 1 to 3, characterized in that a ski jump-like guide device ( 22 ) is formed in the impact region of the wall ( 18 , 19 ). 5. Pump, in particular according to one of claims 1 to 4, characterized in that the jet chamber ( 15 ) is fluidically connected via two suction channels ( 20 ) to at least one suction kidney or suction chamber. 6. Pump, in particular according to claim 5, characterized in that the flow ( 23 ) from the jet chamber ( 15 ) into the two suction channels ( 20 ) is optionally bundled by the design of the flow path and then at least slightly deflected. 7. Pump, in particular according to claim 6, characterized in that the deflection of the flow ( 23 ) serves to influence the volume flow directed into the suction channels ( 20 ) or to influence the distribution of the volume flow. 8. Pump, in particular according to one of claims 5 to 7, characterized in that the suction channels ( 20 ) on both sides of the jet chamber ( 15 ) (right, left and downstream) are designed substantially symmetrically. 9. Pump, in particular according to one of claims 3 to 8, characterized in that a cross-sectional taper ( 24 ) of the flow path serving to concentrate the flow ( 23 ) is arranged downstream of the impact region in the jet chamber ( 15 ). 10. Pump, in particular according to one of claims 3 to 9, characterized in that the impact region in the jet chamber ( 15 ), preferably the cross-sectional taper ( 24 ), is followed by a deflection ( 25 ) and division into the two suction channels ( 20 ). 11. Pump, in particular according to one of claims 1 to 10, characterized in that further means influencing the flow ( 23 ), in particular cross-sectional modifications and/or guide devices ( 26 ), are provided in the suction channels ( 20 ) and/or immediately in front of the suction kidneys. 12. Pump, in particular according to one of claims 1 to 4, optionally according to one of claims 5 to 11, characterized in that the jet chamber ( 15 ) is fluidly connected via a suction channel ( 20 ) to at least two suction kidneys arranged one behind the other. 13. Pump, in particular according to claim 12, characterized in that a cross-sectional taper ( 24 ) of the flow path serving to concentrate the flow ( 23 ) is arranged downstream of the impact region in the jet chamber ( 15 ). 14. Pump, in particular according to claim 13, characterized in that the flow cross-section decreases continuously towards the first suction kidney. 15. Pump, in particular according to one of claims 12 to 14, characterized in that in the suction channel ( 20 ), in particular immediately before the suction kidneys, further means influencing the flow ( 23 ) in the direction into the kidneys, in particular guide devices ( 28 ), are provided. 16. Pump, in particular according to claim 15, characterized in that immediately in front of the suction kidneys, ski jump-like guide devices ( 28 ) are formed. 17. Pump, in particular according to claim 15 or 16, characterized in that the guide devices ( 28 ) are integral components of the housing ( 2 , 3 , 4 ) and/or the flange and/or the cover. 18. Pump, in particular according to one of claims 12 to 17, characterized in that the flow cross-section between the first suction kidney and the second suction kidney is smaller than the flow cross-section in front of the first suction kidney. 19. Pump, in particular according to one of claims 12 to 18, characterized in that the flow cross-section between the first suction kidney and the second suction kidney preferably decreases continuously. 20. Pump, in particular according to one of claims 12 to 19, characterized in that a baffle wall ( 29 ) causing a deflection is formed behind the second suction kidney. 21. Pump, in particular according to one of claims 12 to 20, characterized in that the suction channel ( 20 ) in the region between the two suction kidneys or after the rearmost suction kidney in the flow direction is flow-connected to the jet chamber ( 15 ) or the region of the suction channel ( 20 ) before the first suction kidney directly or via a bypass. 22. Pump, in particular according to one of claims 1 to 22, characterized in that the inner walls of the jet chamber ( 15 ) and/or the suction channel ( 20 ) or the suction channels for influencing the flow ( 23 ) are surface-treated. 23. Pump, in particular according to one of claims 1 to 22, wherein the housing is closed on one side by a front housing cover ( 3 ) and on the other side optionally by a bearing flange ( 4 ), characterized in that the jet chamber ( 15 ) formed on both sides of the conveying device ( 1 ) is at least largely incorporated into the housing cover ( 3 ) and optionally into the bearing flange ( 4 ). 24. Pump, in particular for conveying a fluid, in particular a vane pump, with a conveying device ( 1 ) accommodated in a housing ( 2 ), a supply channel ( 13 ) for the fluid formed in the housing ( 2 ), which is connected to the suction area of the conveying device ( 1 ) and opens into a jet chamber ( 15 ) upstream of the conveying device ( 1 ), and with an injector device ( 14 ) which serves to convey the fluid, jets with a jet nozzle ( 17 ) into at least one jet chamber ( 15 ) and injects fluid flowing at high speed into the fluid emerging from the supply channel ( 13 ) into the jet chamber ( 15 ) and thereby entrains or accelerates it, wherein the jet chamber ( 15 ) is connected via at least one suction channel ( 20 ) to at least two suction kidneys of the conveying device ( 1 ) is fluidly connected, characterized by at least one feature disclosed in the application documents.