WO2018229244A1

WO2018229244A1 - Pump assembly

Info

Publication number: WO2018229244A1
Application number: PCT/EP2018/065928
Authority: WO
Inventors: Arno Steiner; Heinrich Hecher; Matthias INNERBICHLER; Alessandro DE NICOLÒ; Omar FRANCESCHI; Tomasz MALOGOWSKI
Original assignee: Gkn Sinter Metals Ag
Priority date: 2017-06-16
Filing date: 2018-06-15
Publication date: 2018-12-20
Also published as: DE102018108192A1; US20210140427A1; JP2020528521A; CN110998064A; IT201700067438A1; EP3638883A1

Abstract

The invention relates to a pump assembly (1) which comprises at least one housing (2) and two gears (6, 7) as transfer means and a drive shaft (15). The housing (2) comprises at least one base (3) and a cover element (4) which can be connected together in order to form a pressure chamber (5). Each of the two gears (6, 7) has a toothing (8) on the outer circumferential surface and engage into one another via the toothing (8) in order to transfer a fluid. The gears (6, 7) are arranged in the pressure chamber (5) between the base (3) and the cover element (4) along an axial direction (9). The drive shaft (15) extends along the axial direction (9) into the housing (2) via an opening (16) in the cover element (4). The first gear (6) is arranged on a first bearing bush (10), wherein the first bearing bush (10) is mounted solely in the base (3), and the first gear (6) is connected to the drive shaft (15) via a formfitting connection in the circumferential direction (25).

Description

pump assembly

The invention relates to a pump arrangement. The pump assembly is provided for delivery of a fluid. The pump assembly includes a housing in the housing conveying means for conveying a fluid from a fluid inlet to a fluid outlet and a drive shaft for driving the conveying means. Fluid inlet and fluid outlet are disposed on the housing. At least one of the conveying means is driven via the drive shaft, which extends from outside the housing into the housing. Here are provided as funding two intermeshing gears. Each gear has a toothing on the peripheral surface, wherein the gears are coupled together via the toothing. The drive shaft is z. B. assigned to an electrical drive, which is arranged outside the housing of the pump assembly.

The gears have rotational axes, which are oriented in particular along an axial direction. The gears are arranged in a radial direction next to each other and overlapping in the axial direction, wherein the axes of rotation are arranged parallel to each other.

The drive shaft also has an axis of rotation, which is arranged in particular parallel to the axes of rotation of the gears and preferably coaxially to the axis of rotation of a gear.

In such a pump arrangement, the conveying means can be arranged on shafts and the shafts can be mounted on bearings on both sides of the conveying means in the housing. Furthermore, a drive shaft can be directly connected to the conveyor. tied and the funding to be stored on the drive shaft at bearings. Beared means here in particular that in a radial direction (possibly in addition in an axial direction) acting forces at least in a radial direction (possibly also in the axial direction) via the conveyor on the shaft or on the bearing of the shaft in the Housing (ie, for example, on the base plate and the cover element) can be transferred. However, a bearing of the shaft on both sides of the conveyor requires precise coordination of the position tolerances of the bearing points on the housing. In particular, so uneven loads on the bearings and bending loads of the waves can occur.

On this basis, it is an object of the present invention, at least partially solve the problems described with reference to the prior art. In particular, a pump arrangement is to be proposed, which is as simple and easy as possible, with an uneven loading of the bearings should be reduced or even avoided.

To solve this problem, a pump assembly according to the features of claim 1 is proposed. Advantageous developments are the subject of the dependent claims. The individually listed in the claims features can be combined with each other in a technologically meaningful way and can be supplemented by explanatory facts from the description and details of the figures, with further embodiments of the invention are shown. A pump arrangement contributes to this, wherein the pump arrangement comprises at least the following components:

a housing having at least one base plate and a lid member connectable together to form a pressure space; (at least) two gear wheels (as conveying means), wherein the gear wheels each have a toothing on an outer circumferential surface and mesh with each other via the toothing for conveying a fluid; wherein the gears are arranged in an axial direction between the base plate and the lid member in the pressure space; and

a drive shaft extending into the housing along the axial direction via an opening in the lid member.

At least a first gear of the two gears is driven as a drive gear on the drive shaft. At least the first gear is designed as a ring gear, wherein the first gear is disposed on a first bearing bush. The first bearing bush is only stored in the base plate. The first gear is connected via a positive connection in a circumferential direction with the drive shaft.

In particular, the second gear is designed as a ring gear, wherein the second gear can be arranged on a second bearing bush. The second bearing bush can be stored (only or alternatively) in the base plate or the cover element.

Here are provided as funding two intermeshing gears. Each gear has a toothing on the outer peripheral surface, wherein the gears are coupled to each other via the toothing. The gears each have an axis of rotation, which is oriented in particular along an axial direction. The gears are arranged side by side in a radial direction and overlapping each other in the axial direction, the axes of rotation being arranged parallel to one another. The drive shaft also has an axis of rotation, which is arranged in particular parallel to the axes of rotation of the gears and preferably coaxially to the axis of rotation of a gear.

The housing is formed at least by a base plate and a lid member. These are arranged one behind the other along the axial direction, with the gears being positioned between them. Base plate and cover element surround the gears in a radial direction outside and thus form the pressure chamber. The pressure chamber is connected to a fluid inlet and a fluid outlet, so that a fluid can be delivered to the fluid outlet via the fluid inlet and the pressure chamber.

In particular, the bearing bushes are designed as so-called plain bearings or friction bearings. In the plain bearing / friction bearing, the two parts moving relative to one another (here gearwheel and bearing bush or bearing bush and housing, ie base plate and cover element) have direct contact. They slide against each other against the resistance caused by sliding friction. This can be kept low by choosing a low-friction material pairing, by lubrication or by creating a lubricating film (full lubrication), which separates the two Kontaktfiachen from each other. But it can also be provided rolling bearings, in which case a rolling bearing between the housing and bearing bush or between bearing bush and gear is arranged.

In particular, the fluid delivered by the pump serves as a lubricant for storage. In this case, special fluid guides may be provided in the base plate and / or the lid member, through which a part of the pumped by the pump fluid is passed to the bearing point. Here it is proposed that at least the first gear, and in particular each gear, which acts as a conveyor, only on one side of the gear (or one side) in the housing (ie either in the base plate or in the cover element, in the case of the first gear in the Base plate) is mounted on the bearing bush. The intended for the storage of each gear bearing bush extending from the gear only to the base plate or towards the lid member. Thus, the bearing bush is mounted or attached only on one side of the gear in the housing, so has only one (single) bearing point. In the radial direction acting forces are transmitted from the gear to the bearing bush (via the bearing between the gear and bearing bush) and from the bearing bush on the present on only one side of the gear bearing (between bearing bush and housing) on the housing.

In particular, both components of the first bearing bushing group and the second bearing bushing are mounted or fastened only in the baseplate. In particular, both bearing bushes extend starting from the respective gear toward the same part of the housing, ie also in the same axial direction.

This arrangement is particularly advantageous because so only on one of the parts of the housing, ie on the base plate, a corresponding tolerance of the situation must be made.

In particular, it is proposed that a sliding bearing between the (each) bearing bush and the (each) designed as a ring gear is provided. Preferably, the bearing bush is fixed or captive in the housing (ie in the base plate or in the cover member) arranged so that in particular a bending load of the bearing bush can be reduced or a defined force transfer from the bearing bush to the housing via the bearing between bearing bush and Housing can be done. In particular, an intermediate element is arranged along the axial direction between the base plate and the cover element, wherein the intermediate element encloses the gear wheels in a radial direction on the outside and forms the pressure space together with the base plate and the cover element. The intermediate element is in particular a disc element that is tolerated with respect to a width of the gears and thus defines a length of the pressure chamber along the axial direction. In particular, at least the base plate and the cover element (possibly additionally the intermediate element) are aligned with one another via connecting elements and connected to one another. In particular, at least one of the connecting elements extends along the axial direction through the intermediate element and connects the base plate and the cover element.

Here it is proposed that at least the first gear can be driven as a drive gear via a drive shaft, wherein the drive shaft via an opening in the cover element (directly) is connected to the drive gear. It is possible to drive each of the gears via a respective drive shaft.

In particular, no force acting in the radial direction is transmitted from the gears via the drive shaft to the housing via the drive shaft. In particular, therefore, the drive shaft only transmits a drive torque acting in the circumferential direction to the drive gearwheel.

In particular, the drive shaft is arranged with respect to the first gear and the first bearing bush in a radial direction with a game. A game here means that a certain displacement of the drive shaft relative to the first gear along the radial direction is possible without a force in the radial direction is transmitted from the drive shaft to the first gear or vice versa. In particular, a play of at least 0.2 mm [millimeters], preferably of at least 0.5 mm, provided so that in a concentric arrangement of the drive shaft and the first gear, a displacement of at least 0.2 mm (or at least 0, 5 mm) along the radial direction in the manner described above is possible.

In particular, the drive shaft is arranged exclusively outside the housing relative to a force acting in a radial direction.

Preferably, the drive shaft is part z. As an electric drive or a transmission, wherein the drive shaft is mounted on at least two, along the axial direction spaced-apart bearing points (but always outside the housing).

Preferably, the (in the circumferential direction acting) positive connection via an inner peripheral surface of the first gear and an outer peripheral surface of the drive shaft is formed, for. B. via an internal toothing of the first gear and an outer toothing of the drive shaft.

Specifically, the drive shaft and the first gear or the drive shaft and the first bushing form a stop against displacement along the axial directions. About the stop positioning of the drive shaft and the first gear along the axial direction is possible. In particular, a clearance between the drive shaft and the first gear or between the drive shaft and the first bearing bush is provided during operation of the pump assembly, so that no axial forces can be transmitted. In particular, the drive shaft has an end-side taper, so that the drive shaft when inserted into the housing z. B. can be performed over the first bearing bush relative to the radial direction. In particular, the end-face taper only serves to ensure a clearance between the drive shaft and the first bearing bush during operation of the pump arrangement. This can ensure that no forces acting in the radial direction are transmitted.

In particular, the first bearing bush is connected to the base plate via a press fit. Preferably, the second bearing bush (alternatively) is connected to the base plate or the cover element via a press fit. Press fit here means that before joining the bearing bush and housing, an outer diameter of the bearing bush (slightly) is greater than an inner diameter of the receiving bore (in the housing) for the bearing bush.

In particular, the first bearing bush is integrally connected to the base plate and executed in one piece. The second bearing bush is preferably connected in a material-bonded manner to the base plate or the cover element and embodied in one piece (for example embodied as a one-part or multi-part green compact and then sintered together). Cohesive connections are all compounds in which the connection partners are held together by atomic or molecular forces. They are at the same time non-detachable connections, which can only be separated by destruction of the connecting means.

In particular, at least the base plate and the cover element are at least partially designed as sintered parts. In particular, at least the first bearing bush is designed as a sintered part. Preferably, both bushings are at least partially executed as sintered parts. Particular preference is given to at least one of the following components, if appropriate several or all of the following components, as sintered components: Part carried out: the base plate, the cover element, the intermediate element, the bearing bushes, the gears, the connecting elements.

A sintered part is a component pressed from a powdery material (green compact), which was subsequently fed to a sintering process. In particular, at least one, preferably all of: the base plate, the cover element, the intermediate element, the bearing bushes, the gears, the connecting elements, is made of a metallic powder by pressing and sintering. In particular, bearing bushes and the part of the housing receiving the bearing bushes are produced as separate green compacts (preferably made of different materials), joined together as green compacts (preferably with the formation of an interference fit) and then sintered together.

As a precaution, it should be noted that the number words used here ("first", "second",...) Primarily (only) serve to distinguish between a plurality of identical objects or variables, ie in particular no dependence and / or order of these objects or quantities obligatory to each other. If a dependency and / or order are required, this is explicitly stated here or it obviously results for the person skilled in the art when studying the concretely described embodiment.

The invention and the technical environment will be explained in more detail with reference to FIGS. It should be noted that the invention should not be limited by the embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description and / or figures. In particular, it should be noted that the figures and in particular the illustrated proportions are only schematic. Same reference numerals denote the same objects, so that, if necessary, explanations from other figures can be used in addition. Show it:

1 shows a first pump arrangement in a perspective view and in an exploded view;

Fig. 2: the pump assembly of Figure 1 in a side view in section.

3 shows a further pump arrangement in a side view in section;

FIG. 4 shows the pump arrangement according to FIG. 3 in a further side view; FIG. a pump assembly in a perspective view and in an exploded view; a detail of the pump assembly of Figure 5 in a side view. a further detail of the pump assembly of Figure 5 in a side view. and the detail of FIG. 7 in a further side view.

1 shows a first, known pump arrangement 1 in a perspective view and in an exploded view. Fig. 2 shows the pump assembly 1 of FIG. 1 in a side view in section. FIGS. 1 and 2 will be described together below.

The pump arrangement 1 comprises a housing 2 and in the housing 2 conveying means for conveying a fluid from a fluid inlet 20 to a fluid outlet. Gear 21 fluid inlet 20 and fluid outlet 21 are arranged on or in the housing 2. The housing 2 comprises a base plate 3 and a cover element 4 and an intermediate element 12 which can be connected to one another via connecting elements 24 to form a pressure chamber 5. The conveying means are along an axial direction 9 between the base plate 3 and the cover element 4 in the pressure chamber 5 arranged. The intermediate element 12 surrounds the gears 6, 7 in a radial direction 13 on the outside. The intermediate element 12 is a disk element that is tolerated with respect to a width of the gears 6, 7 and thus defines a length 17 of the pressure chamber 5 along the axial direction 9 - niert. One of the conveying means is driven by a drive shaft 15 which extends from outside the housing 2 into the housing 2. Here, two intermeshing gears 6, 7 are provided as funding. Each toothed wheel 6, 7 has a toothing 8 on the outer circumferential surface, wherein the toothed wheels 6, 7 are coupled together via the toothing 8 for conveying a fluid.

The gears 6, 7 have axes of rotation 22 which are oriented along an axial direction 9. The toothed wheels 6, 7 are arranged next to one another in a radial direction 13 and overlapping in the axial direction 9, the axes of rotation 22 being arranged parallel to one another.

The conveying means are arranged on shafts 15, 23 and the shafts 15, 23 are mounted on bearings 19 (eg via slide bearings 18) on both sides of the conveying means in the housing 2, in this case in the base plate 3 and in the cover element 4. Furthermore, a drive shaft 15 is connected directly to the conveyor and the conveyor mounted on the drive shaft 15 at bearings 19. Stored here means that in a radial direction 13 (possibly additionally in an axial direction 9) acting forces at least in a radial direction 13 (possibly also in the axial direction 9) via the conveyor to the shaft 15, 23 and the depository 19 of Shaft 15, 23 are transmitted in the housing 2. However, a bearing of the shaft 15, 23 on both sides of the conveyor requires precise coordination of the positional tolerances of the bearings 19 on the housing 2. Here can uneven loads on the bearings 19 and bending loads of the shafts 15, 23 occur.

Fig. 3 shows a further pump arrangement 1 in a side view in section. Fig. 4 shows the pump assembly 1 of FIG. 3 in a further side view in section. FIGS. 3 and 4 will be described together below. Reference is made to the comments on FIGS. 1 and 2.

The pump assembly 1 comprises a housing 2 and two gears 6, 7 as conveying means. The housing 2 comprises a base plate 3, an intermediate element 12 and a cover element 4, which can be connected to one another via connecting elements 24 (as in FIGS. 1 and 2) to form a pressure chamber 5. The two toothed wheels 6, 7 each have an outer peripheral surface a toothing 8 and engage on the teeth 8 for conveying a fluid into one another. The gears 6, 7 are arranged along an axial direction 9 between the base plate 3 and the cover element 4 in the pressure chamber 5. The first gear 6 and the second gear 7 are each designed as a ring gear, wherein the second gear 7 is disposed on a second bearing bush 11 and the first gear 6 directly on the drive shaft 15. The second bearing bush 11 is arranged only in the cover element 4. The gears 6, 7 have axes of rotation 22 which are oriented along an axial direction 9. The gears 6, 7 are arranged in a radial direction 13 adjacent to each other and in the axial direction 9 overlapping, wherein the axes of rotation 22 are arranged parallel to each other. Base plate 3, intermediate element 12 and cover element 4 are arranged one behind the other along the axial direction 9, the gears 6, 7 being positioned between them. The intermediate member 12 encloses the gears 6, 7 in a radial direction 13 outside and thus forms with the other parts of the housing 2 the pressure chamber 5. The intermediate member 12 is a disc member, which is tolerated with respect to a width of the gears 6, 7 and thus defining a length 17 of the pressure chamber 5 along the axial direction 9.

The second bearing bush 11 is designed as a so-called slide bearing 18. In the sliding bearing 18, the two relatively moving parts (here second gear 7 and second bushing 11) have direct contact. They slide against each other against the resistance caused by sliding friction and form the bearing 19 for the second gear. 7

The second gear 7 is thus mounted only on one side of the second gear 7 in the housing 2, here in the cover member 4 via a bearing point 19. The provided for the storage of the second gear 7 second bearing bush 11 extends, starting from the second gear 7 only to the cover element 4. Thus, the second bearing bush 11 is mounted or attached only on one side of the second gear 7 in the housing 2, so has only one bearing 19 on. In the radial direction 13 acting forces are transmitted from the second gear 7 to the second bushing 11 and from the second bushing 11 via the present on only one side of the second gear 7 bearing 19 on the housing 2.

The first gear 6 is arranged here as a drive gear 14 directly on the drive shaft 15. The drive shaft 15 transmits a drive torque acting in the circumferential direction 25 (see arrow in FIG. 4) to the drive gearwheel 14. The first gearwheel 6 is not supported in the housing 2. The drive shaft 15th extends along the axial direction 9 via the opening 16 into the housing 2 inside. The drive shaft 15 is supported only outside the housing 2 in an electric drive 31. There are arranged along the axial direction 9 two bearings 19 spaced from each other. About the bearings 19 13 acting forces in the radial direction (see arrows in Fig. 4), starting z. B. derived from the first gear 6 via the drive shaft 15 in the electric drive 31.

5 shows a pump arrangement 1 in a perspective view and in an exploded view (here without drive shaft 15). On the comments on Fig. 1 and Fig. 3 can be used in addition.

The pump assembly 1 comprises a housing 2 and two gears 6, 7 as conveying means. The housing 2 comprises a base plate 3, an intermediate element 12 and a cover element 4, which can be connected to one another via connecting elements 24 (as in FIGS. 1 and 2) to form a pressure chamber 5.

The two gearwheels 6, 7 each have a toothing 8 on an outer circumferential surface and engage with one another via the toothings 8 for conveying a fluid. The gears 6, 7 are arranged along an axial direction 9 between the base plate 3 and the cover element 4 in the pressure chamber 5. The first gear 6 and the second gear 7 are each designed as a ring gear, wherein the first gear 6 is arranged on a first bearing bush 10 and the second gear 7 on a second bearing bush 11. The first bearing bush 10 and the second bearing bush 11 are each arranged only in the base plate 3. The gears 6, 7 have axes of rotation 22 which are oriented along an axial direction 9. The gears 6, 7 are arranged in a radial direction 13 adjacent to each other and in the axial direction 9 overlapping, wherein the axes of rotation 22 are arranged parallel to each other. Base plate 3, intermediate element 12 and cover element 4 are arranged one behind the other along the axial direction 9, the gears 6, 7 being positioned between them. The intermediate member 12 encloses the gears 6, 7 in a radial direction 13 outside and thus forms with the other parts of the housing 2 the pressure chamber 5. The intermediate member 12 is a disc member, which is tolerated with respect to a width of the gears 6, 7 and thus defining a length 17 of the pressure chamber 5 along the axial direction 9. The pressure chamber 5 is connected to a fluid inlet 20 and a fluid outlet 21, so that a fluid can be delivered to the fluid outlet 21 via the fluid inlet 20 and the pressure chamber 5.

The bushings 10, 11 are designed as so-called plain bearings 18. In the sliding bearing 18, the two relatively moving parts (here gear 6, 7 and bearing bush 10, 11) have direct contact. They slide against each other against the resistance caused by sliding friction and form the bearing point 19 for the gear 6, 7.

Each gear 6, 7 is thus mounted only on one side of the gear 6, 7 in the housing 2, here in the base plate 3 via bearings 19. The provided for the storage of each gear 6, 7 bearing bush 10, 11 extending from the gear 6, 7 only to the base plate 3. Thus, the bearing bush 10, 11 only at one side of the gear 6, 7 stored in the housing 2 or ., So has only one bearing point 19.

A sliding bearing 18 is provided between each bushing 10, 11 and the gear wheel 6, 7 each designed as a ring gear. The bushings 10, 11 are fixed in the housing 2 (ie in the base plate 3). The base plate 3 and the cover element 4 and additionally the intermediate element 12 are aligned with each other via connecting elements 24 and connected to each other. The connecting elements 24 extend along the axial direction 9 through the intermediate element 12 and connect the base plate 3 and the cover element 4.

One of the gears 6, 7 can be driven as a drive gear 14 via a drive shaft 15 (see FIG. 6), wherein the drive shaft 15 can be connected to the drive gear 14 via an opening 16 in the cover element 4. It can be seen on the drive gear 14, an internal toothing 26 is arranged, which cooperates with the drive shaft 15 for driving the drive gear 14.

FIG. 6 shows a detail of the pump arrangement 1 according to FIG. 5 in a side view. FIG. 7 shows a further detail of the pump arrangement 1 according to FIG. 5 in a side view. FIGS. 6 and 7 will be described together below. Reference is made to the comments on FIG. 5.

In Fig. 6, only the gears 6, 7, the bearing bushes 10, 11 and the drive shaft 15 are shown. In Fig. 7, the base plate 3 is additionally shown. The drive shaft 15 extends along the axial direction 9 via an opening 16 in the cover element 4 into the housing 2 (see FIG. 5). The first gear 6 is connected via a positive connection in a circumferential direction 25 connection (here via the internal teeth 26) to the drive shaft 15. Via the drive shaft 15, no force acting in the radial direction 13 is transmitted from the gears 6, 7 via the drive shaft 15 to the housing 2. The drive shaft 15 thus only transmits a drive torque acting in the circumferential direction 25 to the drive gear 14. The positive connection acting in the circumferential direction 25 is formed via an inner peripheral surface 28 of the first gear 6 and an outer peripheral surface 29 of the drive shaft 15, here via the internal teeth 26 (see FIG. 5) of the first gear 6 and an outer toothing of the drive shaft 15.

The drive shaft 15 and the first bearing bushing 10 form a stop 30 against displacement along the axial directions 9. About the stop 30, a positioning of the drive shaft 15 and the first gear 6 along the axial direction 9 is possible. During operation of the pump arrangement 1, play is provided in the axial direction 9 between the drive shaft 15 and the first gear 6 and between the drive shaft 15 and the first bearing bush 10.

Next, the drive shaft 15 has an end-side taper 32, so that the drive shaft 15 when inserted into the housing 2 z. B. over the first bearing bush 10 relative to the radial direction 13 is guided.

The drive shaft 15 is arranged with respect to the first gear 6 and the first bearing bush 10 in a radial direction 13 with a game 27. A clearance 27 means that a certain displacement of the drive shaft 15 with respect to the first gear 6 (and with respect to the first bearing bush 10) along the radial direction 13 is possible without a force in the radial direction 13 from the drive shaft 15 to the first gear 6 or vice versa. The play 27 between the first gear 6 and the drive shaft 15 corresponds to half the difference of the diameter of the first gear 6 and drive shaft 15 in the region of the positive connection in the circumferential direction 25 between the first gear 6 and the drive shaft 15. This positive connection is formed via the internal teeth 26 on the inner peripheral surface 28 of the first gear 6 and the external teeth on the outer peripheral surface 29 of the drive shaft 15. So if a game of 0.2 mm is provided, so is at a concentric arrangement of the drive shaft 15 and the first gear 6, a displacement of 0.2 mm along the radial direction 13 in the manner described above possible. In this case, the play 27 is (only) so great that the positive connection in the circumferential direction 25 between the first gear 6 and the drive shaft 15 in any case or at least in a displacement of the drive shaft 15 relative to the first gear 6 in the radial direction thirteenth ) given is.

Fig. 8 shows the detail of Fig. 7 in a further side view. Reference is made to the embodiments of FIG. 7. The drive shaft 15 is arranged exclusively outside the housing 2 with respect to a force acting in a radial direction 13 (see arrows in FIG. 8). The drive shaft 15 is thus part of an electric drive 31, wherein the drive shaft 15 at two, along the axial direction 9 from each other spaced La- places 19 (but always outside the housing 2), is stored. Thus, no force acting in the radial direction 13 on the drive shaft 15 is transmitted from the gears 6, 7 via the drive shaft 15 to the housing 2. The drive shaft 15 transmits only a driving torque acting in the circumferential direction 25 to the drive gear 14.

LIST OF REFERENCE NUMBERS

1 pump arrangement

2 housings

3 base plate

4 cover element

5 pressure chamber

6 first gear

7 second gear

8 toothing

9 axial direction

10 first bearing bush

11 second bearing bush

12 intermediate element

13 radial direction

14 drive gear

15 drive shaft

16 opening

17 length

18 plain bearings

19 bearing point

20 fluid inlet

21 fluid outlet

22 axis of rotation

23 wave

24 connecting element

25 circumferential direction

26 internal toothing game

Inner peripheral surface Outer peripheral surface Stop

electric drive rejuvenation

Claims

claims

Pump arrangement (1), at least comprising

a housing (2) having at least one base plate (3) and a cover element (4) which are connectable to each other to form a pressure chamber (5);

two gears (6, 7) each having on a peripheral outer surface a toothing (8) and via the toothing (8) for conveying a fluid intermesh; wherein the gears (6, 7) are arranged in an axial direction (9) between the base plate (3) and the lid member (4) in the pressure space (5); and a drive shaft (15) extending into the housing (2) along the axial direction (9) via an opening (16) in the lid member (4);

wherein at least a first gear (6) as a drive gear (14) via the drive shaft (15) is drivable; wherein at least the first gear (6) is designed as a ring gear, wherein the first gear (6) on a first bearing bush (10) is arranged, wherein the first bearing bush (10) is mounted only in the base plate (3); wherein the first gear (6) via a in a circumferential direction (25) positive connection with the drive shaft (15) is connected.

Pump arrangement (1) according to claim 1, wherein the drive shaft (15) relative to the first gear (6) and the first bearing bush (10) in a radial direction (13) with a game (27) is arranged.

Pump arrangement (1) according to one of the preceding claims, wherein the drive shaft (15) exclusively outside the housing (2) is disposed relative to a force acting in a radial direction (13) force.

Pump arrangement (1) according to one of the preceding claims, wherein the positive connection via an inner peripheral surface (28) of the first gear (6) and an outer peripheral surface (29) of the drive shaft (15) is formed.

Pump arrangement (1) according to one of the preceding claims, wherein the drive shaft (15) and the first gear (6) or the drive shaft (15) and the first bearing bush (10) against a displacement along the axial directions (9) has a stop (30 ) train.

Pump arrangement (1) according to one of the preceding claims, wherein the first bearing bush (10) is connected to the base plate (3) via a press fit.

Pump arrangement (1) according to one of the preceding claims 1 to 5, wherein the first bearing bush (10) with the base plate (3) is integrally connected and made in one piece.

Pump arrangement (1) according to one of the preceding claims, wherein at least the base plate (3) and the cover element (4) are at least partially designed as sintered parts.

Pump arrangement (1) according to one of the preceding claims, wherein at least the first bearing bush (10) is designed as a sintered part.

Pump arrangement (1) according to one of the preceding claims, wherein the second gear (7) is designed as a ring gear, wherein the second gear (7) on a second bearing bush (11) is arranged, wherein the second bearing bush (11) is mounted only in one of the base plate (3) and cover element (4).