screw pump

Abstract

A screw pump having a main shaft housing (2) in which a drive main shaft (3) and at least one driven main shaft (4) meshing with the drive main shaft are accommodated in a main shaft bore (28), and having an outer housing (5) surrounding the main shaft housing (2), on which an axial inlet connection (6) and a radial outlet connection (9) are provided, wherein the main shaft housing (2) has an axial fluid outlet for fluid being conveyed through the main shaft housing (2) via the drive and driven main shafts (3, 4), which axial fluid outlet communicates with a fluid chamber (10) extending 360° between the main shaft housing (2) and the outer housing (5), which fluid chamber in turn communicates with the radial outlet connection (9).

Description

Technical Field

[0001] The invention relates to a screw pump having a spindle housing in which a drive spindle and at least one driven spindle meshing with the drive spindle are accommodated in a spindle bore, and an outer housing surrounding the spindle housing, on which an axial inlet connection and a radial outlet connection are provided. Background Art

[0002] This type of screw pump is used to pump fluids and has applications in a variety of fields. For example, it can pump fuel or other working fluids or supply fluids such as coolants or cleaning agents in automobiles. This type of screw pump can also be used in other land vehicles and aircraft, such as airplanes or drones, but the possible applications are certainly not limited to these. This screw pump has a spindle housing, also known as an inner housing, in which at least two spindles—a driving spindle and a driven spindle—are housed in corresponding spindle bores, which intersect with each other. The driving spindle and the driven spindle each have a spindle profile, which meshes with each other. The driving spindle is connected to a drive motor and can be actively rotated, which also causes the meshing driven spindle to rotate. The spindle rotation continuously moves the delivery volume toward the longitudinal axis of the spindle, which is used to deliver the fluid. The spindle housing is housed in an outer housing, which can be, for example, cylindrical and closed on one side by an axial wall and, on the other side, flange-mounted for, for example, the drive motor. However, the outer housing can also be composed of multiple parts and have a cylindrical base part that is closed on one side by a top cover and on the other side the drive motor is flange-mounted. The outer housing has an axial inlet connection, i.e., a corresponding connection piece for connecting to the delivery line, which defines the suction side. The outer housing also includes a radial outlet connection, i.e., a corresponding outlet connection piece for defining the pressure side. There, the pumped fluid escapes due to the corresponding pressure that can be generated by the pump. Such a pump is described, for example, in DE 10 2018 131 587 A1.

[0003] In known pumps, an axial inlet connection, eccentrically arranged on the outer housing, is provided through which the feed occurs. The fluid then initially flows laterally toward the axial inlet opening of the spindle housing, is conveyed through it, and leaves the spindle housing at radial housing bores, from where it flows through the narrow connecting space between the spindle housing and the outer housing to the radial outlet connection. In the region of the radial outlet bores and the narrow connecting space of the spindle housing, i.e., on the pressure side, the conveyed fluid experiences a correspondingly high pump pressure, which results in a high pressure locally on the spindle housing or in the region of the intermediate housing where the narrow connecting space is located. Summary of the Invention

[0004] The present invention is based on the following problem: to propose an improved screw pump.

[0005] The solution of the present invention for achieving the above-mentioned object lies in a screw pump as described in the background technology, wherein the main shaft housing has an axial fluid outlet for the fluid to be transported through the main shaft housing via the driving main shaft and the driven main shaft, and the axial fluid outlet is connected to a fluid chamber extending 360° constructed between the main shaft housing and the outer housing, and the fluid chamber is in turn connected to the radial outlet.

[0006] In the screw pump according to the present invention, a radial fluid chamber is advantageously arranged between the spindle housing and the outer housing, the fluid chamber extending 360° around the spindle housing, i.e. surrounding the spindle housing as an annular chamber. The annular fluid chamber is located on the pressure side and is a pressure chamber, because the pressurized fluid escaping from the spindle housing is fed into the fluid chamber. The fluid escapes axially from the spindle housing, i.e., a correspondingly large axial fluid discharge hole is provided on the spindle housing, so that the fluid transported axially along the spindle assembly can escape smoothly axially. No radial drillings or similar structures are provided on the spindle housing side. The axial fluid outlet of the spindle housing is connected to the radial fluid chamber or pressure chamber, i.e., the pressurized fluid is deflected in a suitable manner and transported to the radial fluid chamber.

[0007] As described above, the radial fluid chamber or pressure chamber completely surrounds the inner housing, i.e., surrounds it in a 360° circumferential manner. Therefore, the corresponding pump pressure is particularly advantageously applied all around the inner housing, i.e., ultimately, nearly symmetrical pressure conditions are present or applied to the spindle housing. This, on the one hand, prevents localized pressure increases, such as those caused by asymmetrical pressure distributions known from the prior art. On the other hand, deformations of the spindle housing caused by fluid pressure also building up in the spindle housing are avoided, since, as described above, the spindle housing is loaded radially outward with the fluid pressure in the fluid chamber and is therefore stabilized. Thus, according to the present invention, a fluid jacket is advantageously provided, which generates a corresponding radial pressure that stabilizes the inner housing. This is particularly advantageous when the spindle housing is made of a relatively soft material, such as plastic, as is the case with smaller screw pumps, while still being able to generate correspondingly high pump pressures.

[0008] The fluid chamber provided according to the invention, as described above, extends, on the one hand, through 360° around the spindle housing. On the other hand, the fluid chamber should surround the spindle housing over at least a portion of its axial length. In this case, the fluid chamber should extend over at least half the length of the spindle bore or the spindle housing, and optionally longer, for example approximately two-thirds of the length of the spindle bore or the spindle housing. The fluid chamber can also extend over the entire length of the spindle bore or the spindle housing. This is also advantageous because the fluid escapes axially from the spindle housing, which also reduces any flow noise and thus brings about the desired deflection in the direction of the fluid chamber, which ultimately begins at the pressure-side end of the spindle housing and then extends axially to the suction-side end, with the fluid chamber extending over at least half the length of the spindle housing, and preferably longer.

[0009] The spindle housing should be supported accordingly in the outer housing, just as the fluid chamber must of course be sealed axially accordingly. To this end, different designs can be adopted. According to a first alternative, the fluid chamber can be axially limited by two radial flanges, one of which has a plurality of axial through-holes, through which the fluid chamber is connected to the fluid outlet of the spindle housing. The spindle housing is accommodated in the outer housing and supported radially by these radial flanges. The radial flange arranged on the pressure side has corresponding through-holes, which enable the fluid flowing out axially from the spindle housing to flow back axially roughly into the fluid chamber after its deflection. Of course, there is no need to seal on this side. The other radial flange roughly arranged on the suction side is used for sealing, and for this purpose, one or more suitable seals are provided in this area for sealing the spindle housing toward the outer housing so that the fluid chamber is also sealed at the suction side end.

[0010] As an alternative to constructing two radial flanges, the fluid chamber can also be axially delimited by a radial flange and a cover member, the radial flange having a plurality of axial through-holes, via which the fluid chamber is connected to the fluid outlet of the spindle housing. In this case, only the radial flange provided on the pressure side is used, which, as described in the previous embodiment, has axial through-holes to allow the conveyed pressurized fluid to flow back into the fluid chamber. The other side of the fluid chamber is closed or delimited by a cover member placed on the cylindrical base part of the outer housing. Thus, in the first variant, the suction-side radial flange provides the chamber delimitation, while in the second variant, the axial chamber delimitation is achieved by the cover member.

[0011] As mentioned above, the fluid flowing out axially from the spindle housing should be deflected and sent back radially outward into the fluid chamber. The fluid outlet is ultimately achieved through the axially open side of the spindle housing, and the spindle housing is preferably centered or centrally housed in the outer housing. In order to achieve deflection and backflow in a simple manner, a further advantageous solution is proposed, which arranges an intermediate member placed on the outer housing, the intermediate member being suitable for connecting a drive motor, wherein one or more deflection cavities are constructed on the intermediate member to deflect the fluid from the fluid outlet of the main shaft housing to the fluid chamber. On the one hand, the intermediate member (which can also be a coupling or an adapter flange) is axially placed on the outer housing and the intermediate member is fixed to the outer housing. On the other hand, the intermediate member also forms a mounting interface for the drive motor axially placed on the intermediate member, and the drive motor extends with its drive shaft through the intermediate member to a suitable coupling device, and the drive shaft is coupled to the drive spindle of the spindle group through the coupling device. According to the invention, one or more deflection cavities, i.e., one or more recesses, depressions, or spaces, are provided in the intermediate component, into which the fluid axially escaping from the spindle housing enters. These deflection cavities extend approximately radially outward and communicate with the fluid chamber via a plurality of openings, for example, provided in a radial flange on the pressure side of the spindle housing. The one or more deflection cavities can deflect the axially escaping fluid radially outward and axially back into the fluid chamber approximately around the entire circumference, thereby achieving inflow to the chamber not only locally but ultimately around the entire circumference of the chamber.

[0012] In this case, the intermediate component can be sealed from the drive motor or the drive shaft passing through it. This can be achieved using a shaft sealing ring, so no fluid flows into the drive motor to cool it. In this case, the drive motor is a dry rotor. If no sealing device is provided, that is, no shaft sealing ring is provided, a small amount of fluid can flow into the drive motor, circulate there, and then flow back again, thereby also achieving motor cooling. In this case, the drive motor is a wet rotor.

[0013] However, inserting such an intermediate component is not absolutely necessary. Alternatively, one or more deflection chambers can be provided in the housing of the drive motor, which is mounted on the outer housing, to deflect the fluid from the fluid outlet of the main shaft housing into the fluid chamber. In this case, the motor housing is mounted directly on the outer housing and connected to the outer housing so that fluid escaping from the main shaft housing flows directly into the motor housing, with the one or more deflection chambers being formed in the motor housing. The drive motor can also be designed as a dry rotor, in which case the drive shaft leading from the motor housing is sealed on this side by a shaft sealing ring. In a wet rotor embodiment, no shaft sealing ring is provided at this location, so a certain amount of fluid can flow into the drive motor for cooling purposes.

[0014] Preferably, a deflection cavity is provided in the form of an annular groove or cylindrical depression, which is preferably circular in the region of the groove or depression base. In other words, the intermediate component or end wall of the motor housing is provided with a corresponding, annular groove or concave or dome-shaped depression extending 360° around the motor housing, which allows for fluid deflection on all sides. This ensures a symmetrical flow of the fluid into the fluid chamber in a simple manner. Of course, for example, for stabilization purposes, the groove can also be divided into separate groove parts by axially and radially extending webs (if such webs are provided).

[0015] As mentioned above, the fluid chamber itself is sealed toward the outer housing by one or more sealing elements. Depending on the housing design, the sealing elements can be arranged at different positions. If the fluid chamber is axially limited by the radial flange of the spindle housing at the suction side end, the first sealing element can be accommodated in a groove on the radial flange of the spindle housing or the outer housing adjacent to the inlet joint and seal the spindle housing relative to the outer housing. The second sealing element is used to seal on the pressure side. Different variations can be adopted here. Therefore, the second sealing element can be accommodated in the groove of the intermediate member and seal the intermediate member toward the outer housing. If this method is not used, but the drive motor is directly flange-mounted on the outer housing, the second sealing element can be accommodated in the groove of the motor housing of the drive motor and seal the motor housing toward the outer housing. A sealing ring made of an applicable elastomer can advantageously be used as a sealing element.

[0016] If sealing or axial restriction on the suction side is achieved not by a radial flange but by a cover member, in an alternative pump embodiment, a first sealing element can be accommodated in a groove in the spindle housing or the cover member and seals the spindle housing toward the cover member. This creates a first sealing plane between the cover member and the spindle housing. Furthermore, a second sealing element can be accommodated in a groove in the outer housing or the cover member and seals the outer housing toward the cover member. This creates a second sealing plane between the cover member and the outer housing.

[0017] To achieve sealing on the pressure side, two variations can also be employed, as described in the previous embodiments. Thus, the third sealing element can be housed in a receiving groove in the intermediate component or the outer housing, sealing the intermediate component toward the outer housing. If no intermediate component is used, the third sealing element can be housed in a receiving groove in the motor housing of the drive motor, sealing the motor housing toward the outer housing.

[0018] As described above, the fluid or pressure sheath implemented according to the present invention by the fluid chamber can specifically generate a stable radial pressure applied to the spindle housing in all directions in order to avoid the expansion of tolerances on the spindle housing or any minor geometric changes related to operation. The above solution can be used in particular if the spindle housing is made of plastic, as provided in accordance with the present invention. In addition, as a supplement or alternative, the outer shell, the intermediate component and / or the top cover component can also be made of plastic. In other words, all components related to the housing can be made of plastic, but in addition, the spindle itself can also be made of plastic in principle. However, preferably, at least these spindles are made of metal.

[0019] As mentioned above, the screw pump can include a drive motor, which is coupled to the drive spindle via a drive shaft and is either implemented as a dry rotor, in which the drive spindle is radially sealed by a shaft sealing ring, or as a wet rotor, in which a portion of the fluid escaping axially from the spindle housing flows along the drive shaft into the drive motor.

[0020] Screw pumps can be two-spindle pumps, with just one drive spindle and one driven spindle positioned laterally relative to it. Alternatively, they can be three-spindle pumps, with a central drive spindle and two driven spindles positioned 180° apart on either side. Thus, different pump types can be implemented around the inner housing using the fluid or pressure chambers according to the invention.

[0021] Furthermore, the inlet connection can be arranged in such a way that it is aligned with the central axis of the spindle group, which comprises the drive spindle and one or two driven spindles. This means that the inlet connection is arranged approximately in the axial extension of the central axis of the spindle group. In the case of a 2-spindle screw pump, the central axis is ultimately located centrally between the drive spindle and the driven spindles. In the case of a 3-spindle pump, the central axis is located in the longitudinal axis of the central drive spindle. This design is particularly advantageous in that the fluid flowing into the outer housing and being axially drawn in does not first need to be deflected into the spindle housing, which could be associated with flow noise. Rather, the fluid can flow axially directly from the inlet connection into the spindle housing.

[0022] In addition to the screw pump itself, the present invention also relates to the use of a screw pump of the aforementioned type for conveying a working fluid in a vehicle. The working fluid can be of any nature. For example, it can be a cleaning fluid, such as windshield washer fluid, which is conveyed by a pump. As an alternative, the preferred use according to the present invention is to use the screw pump as a coolant pump for conveying a coolant. The coolant can be any fluid coolant. The use relates in particular to the use for conveying a coolant for cooling an energy accumulator. Such energy accumulators are increasingly used in motor-driven vehicles and are provided in the form of traction or power batteries of corresponding dimensions. The energy accumulator needs to be cooled accordingly with the aid of a coolant, which can be simply conveyed in the required amount by means of the screw pump according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further advantages and details of the present invention are shown in the following embodiments and drawings, which schematically illustrate:

[0024] Figure 1 A schematic cross-sectional view of a screw pump according to a first embodiment of the present invention is shown.

[0025] Figure 2 With flow arrows Figure 1 Screw pump,

[0026] Figure 3 for Figure 1 and Figure 2 The exploded view of the screw pump shown,

[0027] Figure 4 A partial cross-sectional perspective view of a screw pump according to another embodiment of the present invention is shown.

[0028] Figure 5 for Figure 4 A partial view of a longitudinal section of the intermediate component provided in this embodiment of the arrangement shown,

[0029] Figure 6 To correspond to Figure 5 A cross-sectional view of

[0030] Figure 7 FIG. 4 is a perspective view of a screw pump according to another embodiment of the present invention. DETAILED DESCRIPTION

[0031] Figure 1 A screw pump 1 according to a first embodiment of the invention is shown. The screw pump comprises a spindle housing 2 in which, in the example shown, three spindles, namely a driving spindle 3 and two driven spindles 4 positioned laterally offset by 180° next to the driving spindle 3, are accommodated in corresponding spindle bores that intersect one another. Figure 1As shown, all spindles have corresponding spindle profiles that snap into and mesh with each other.

[0032] The spindle housing 2 is accommodated in a cylindrical outer housing 5, on which a central inlet connection 6, i.e., a corresponding connection piece, is located and aligned with the longitudinal axis of the drive spindle 3. The spindle assembly consisting of the drive spindle 3 and the driven spindle 4 is axially supported relative to the outer housing 5 or its radial flange 7 by a supporting element (here a key 8).

[0033] Furthermore, a radial outlet connection 9 , here also a connecting piece, is provided on the outer housing 5 , through which the pressurized fluid drawn in via the inlet connection 6 can escape radially again.

[0034] like Figure 1 As shown clearly, the spindle housing 2 together with its components is accommodated inside the cylindrical outer housing 5. A 360° surrounding fluid chamber 10 is provided between the outer wall of the inner housing 2 and the inner wall of the outer housing 5. Figure 1 As shown, the fluid chamber extends over half the length of the spindle housing 2 or the spindle bore. Pressurized fluid escaping at the axial fluid outlet of the spindle housing 2 enters the fluid chamber 10, i.e., the axial fluid outlet at the left end of the spindle housing 2 communicates with the fluid chamber 10. This fluid chamber, in turn, communicates with the outlet connection 9.

[0035] Furthermore, a drive motor 11 (illustrated only schematically here) is provided, which is mounted directly on the outer housing 5 and fastened thereto. The drive motor 11 is coupled to the drive spindle 3 via a coupling element 13 by means of a drive shaft 12 (also illustrated only schematically), so that the drive spindle 3 can be actively rotated by the drive motor 11, causing the entire spindle assembly to rotate and axially conveying the fluid drawn in through the inlet connection 6.

[0036] As described above, the fluid escapes from the axial fluid outlet of the spindle housing 2. In this embodiment, the fluid outlet is simply axially open at the pressure-side end. To ensure that the fluid can enter the fluid chamber axially offset with respect to the delivery direction, a deflection cavity 14 is provided in the illustrated example. In this example, the deflection cavity is formed directly on the housing wall of the drive motor 11 facing the spindle housing 2. This deflection cavity 14 (discussed below) is, for example, formed as a circumferential annular groove with a curved or rounded bottom side. This deflects the fluid flowing in approximately centrally radially outward toward the sides and back into the fluid chamber 10, allowing the fluid to enter the fluid chamber 10 through corresponding through-holes 15 formed on the radial flange 19 of the spindle housing 2.

[0037] The fluid chamber 10 is axially limited at the suction side end by a radial flange 16 of the main shaft housing 2. This radial flange is supported on the housing shoulder 17 of the outer housing on the one hand. On the other hand, it extends to the inner wall of the outer housing 5 and is sealed against the outer housing by a sealing element 18, so that the fluid chamber 10 is closed and sealed at this end. At the opposite, pressure side end, there is also a radial flange 19, in which the through hole 15 mentioned is implemented, so that the fluid chamber 10 is open towards this pressure side and the pressurized fluid can flow into the fluid chamber 10 through the deflection chamber 14. On this side, between the outer housing 5 and the motor housing, a sealing is effected by a suitable sealing element 20, so that an overall fluid-tight encapsulation is achieved.

[0038] During operation, the drive main shaft 3 is driven by the drive motor 11, so that the entire main shaft group is set in rotation. The fluid taken in via the inlet connection 6 is axially transported by the main shaft profiles of the main shafts 3, 4, which engage into one another, resulting in an axially moving transport volume, which allows the transport of fluid along the main shaft group.

[0039] The fluid axially escapes at the pressure side end of the main shaft housing 2, which is advantageous in terms of as low noise operation as possible, since no significant flow noise occurs in this regard. The fluid then directly enters the deflection chamber 14, which is, for example, an annular groove or a concave recess, as described above, deflects the fluid radially outwards and axially back, i.e. in the opposite direction to the transport direction of the main shaft group. The fluid enters the fluid chamber 10 through the through hole 15 and via the fluid chamber into the outlet connection 9, where it is discharged.

[0040] As described above, there is a pump pressure in the fluid chamber 10, i.e. an outlet pressure, which can be generated by the screw pump 1, in the fluid chamber 10, which completely surrounds the main shaft housing 2. This pressure acts radially omnidirectionally on the main shaft housing as long as it is surrounded by the fluid chamber 10, which can also be referred to as pressure chamber. As described above, the fluid chamber 10 extends over at least half the length of the main shaft housing 2, preferably over an even longer range, so that the possible best stabilization of the main shaft housing 2 is achieved with respect to any pressure-related geometric changes or tolerance offsets. The above is particularly applicable when the main shaft housing 2 is made of plastic, i.e. a softer material compared to metal.

[0041] Figure 2 The same applies to Figure 1 the same, which shows the respective flow arrows to represent the fluid flow. As Figure 2As shown, a fluid, such as water, fuel, coolant, etc., is drawn in at the inlet connection 6 and conveyed axially through the spindle assembly through the spindle housing 2. The fluid escapes at the pressure-side end of the open spindle housing 2 and enters the deflection chamber 14. There, supported by the geometry of the deflection chamber, which is circular at the bottom, as described above, the fluid is deflected radially outward and in the opposite direction to the inflow direction. This allows the fluid to flow axially through the through-hole 15 back into the fluid chamber 10, filling it completely. From the fluid chamber 10, the fluid then flows to the outlet connection 9, where it is discharged under pressure.

[0042] Figure 3 for Figure 1 and Figure 2 Exploded view of the screw pump 1. Starting from the right, the outer housing 5 is shown with its axial inlet connection 6 and radial outlet connection 9. At the end facing the drive motor 11 in the assembled position, the outer housing has a mounting flange 21 which is fastened to the motor housing 23 of the drive motor by means of a corresponding mounting flange 22 using suitable fixing screws 24.

[0043] The cross-shaped key 8 is then shown, on which the driving spindle 3 and the driven spindle 4 are axially supported. The cross-shaped structure of the key 8 enables the spindle housing 26 to be mounted in two orientations offset by 90° relative to the outer housing 5, wherein in each of the two mounting positions, the spindles 3, 4 are axially supported on the key 8.

[0044] Furthermore, the spindle housing 2 is shown with its radial flange 16, on which a corresponding receiving groove 25 is formed, in which a sealing element 18 is received, which seals against the outer housing 5 in the assembled position. The spindle housing 2 is connected to the outer housing 5 by means of corresponding connecting screws 26, which are passed through corresponding bores 27 in the radial flange 16 and screwed into threaded bores in the outer housing 5, not shown in detail here.

[0045] Furthermore, a driving spindle 3 and two driven spindles 4 are shown, which are inserted as shown in FIG. Figure 3 The spindle bores 28 shown intersect each other.

[0046] Also shown is the coupling element 13, which is inserted into a corresponding socket at the axial end face of the drive spindle 3 in a rotationally fixed manner and has a corresponding socket 28 into which a pin 29 of the drive shaft 12 of the drive motor 11 engages, thereby achieving a rotationally fixed connection between the drive shaft 12 and the drive spindle 3. Furthermore, two thrust bearings 30 in the form of axially protruding pins provided on the motor housing 23 are shown, which serve to axially support or bear the two driven spindles 4. Also shown is an axial flange 31, which is formed on the motor housing 23 and has corresponding radial grooves 23, into which the sealing element 20 for sealing against the outer housing 5 is inserted.

[0047] As mentioned above, the fluid chamber 10 is delimited on the suction side by a radial flange 16. A radial flange 19 is also shown, but it is open via a through hole 15 so that fluid from the deflection chamber 14 (shown on the motor housing 23) can flow into the fluid chamber 10.

[0048] Figure 4 A partial view of a screw pump according to another embodiment of the present invention, the structure of which corresponds to Figures 1 to 3 The structure shown here again includes an outer housing 5 with an axial inlet connection 6 and a radial outlet connection 9, and a spindle housing 2 with a drive spindle 3 and two driven spindles 4 arranged therein. A fluid chamber 10 is formed between the inner housing 2 and the outer housing 5, extending 360° around the spindle housing 2 and, viewed axially, over at least half the length of the spindle housing. Sealing is again achieved on the suction side by a corresponding radial flange 16 and a sealing element 18 accommodated in a groove 25.

[0049] Unlike the above-described construction, here, the motor housing 23 is not placed directly on the mounting flange 21 of the outer housing 5. Instead, in this variant, an intermediate component 33 in the form of an intermediate plate is provided, which is placed between the mounting flange 21 and the mounting flange 22. An annular groove-shaped or dome-shaped deflection chamber 14 is formed on the intermediate component 33, which has a corresponding axial flange 34, by means of which the intermediate component is axially engaged in the outer housing 5. The drive motor 11, with its drive shaft 9, passes through a corresponding bore in this intermediate component and, as described above, is coupled to the drive spindle 3 via the coupling element 13.

[0050] Therefore, in this inventive variant, the fluid is deflected by a plate-shaped intermediate component 33, on which a deflection chamber 14 is formed. This deflection chamber is shaped so that the fluid is conveyed radially outward and deflected in a direction opposite to the conveying direction, so that the fluid can flow into the fluid chamber 10 through corresponding through-holes 15 in the radial flange 19 of the spindle housing 2 and form a corresponding stable pressure in the fluid chamber 10.

[0051] Figure 5 and Figure 6 Two 90°-staggered sectional views are shown through the plate-like intermediate component 3. As shown, the intermediate component is screwed to the mounting flange 21 of the outer housing 5 via corresponding fixing screws 35. In this embodiment, the sealing element 20 is accommodated in a corresponding annular groove 36 formed on the axial flange 34 and seals radially toward the outer housing 5.

[0052] Furthermore, a central borehole 37 is shown, through which the drive shaft 9 passes. Intermediate component 37 also serves as a motor support, as the drive shaft is ultimately mounted or guided in this borehole 37. If a sealing element in the form of a shaft sealing ring is provided in borehole 37, axial flow of fluid along the drive shaft 9 into the deflection chamber 14 is eliminated, resulting in a dry rotor in the drive motor 11. If no shaft sealing ring is provided in borehole 37, a small amount of fluid can flow axially along the drive shaft 9 into the drive motor 11 and cool it.

[0053] exist Figure 5 In the sectional view shown, the annular or dome-shaped shape of the deflection chamber 14 can be clearly seen, with a circular bottom region 38 that promotes fluid deflection. The sectional plane here passes through the driving spindle 3 but not through the driven spindle 4.

[0054] Figure 6 This is a 90° rotated sectional view, the section plane here passing through the drive spindle 4. The sectional view shows two thrust bearings 30 in the form of support pins, wherein these thrust bearings 30 are integrally formed on the intermediate component 33. A driven spindle 4 is axially supported on each thrust bearing 30.

[0055] at last, Figure 7 A third embodiment of a screw pump 1 according to the invention is shown, comprising an outer housing 5, which consists here of a cylindrical base part 39 and a cover component 40 mounted axially thereon and closing the outer housing 5 toward the suction side. A drive motor 11 is arranged on the opposite pressure side; it can be screwed directly to the base part 39 or, as described above, via an intermediate component 33.

[0056] In addition, a spindle housing 2 is provided, in which only the driving spindle 3 and the driven spindle 4 are accommodated. Figure 1-6 The structure shown is different, this screw pump is a dual-spindle pump. But the basic working principle is the same.

[0057] In this embodiment, the inlet connection 6 is formed on the cover component 40, as is the outlet connection 9. That is, the cover component 40 forms an axial cover on the one hand, but also has the inlet and outlet connections 6, 9 on the other hand.

[0058] For sealing, an axial flange 41 is formed on the cover component 40 , which has an annular groove 42 , into which a sealing element 43 in the form of a sealing ring is inserted, thereby achieving axial sealing toward the spindle housing 2 .

[0059] A further sealing plane is provided between the cover component 40 and the base part 39 . A radially open annular groove 44 is again formed on the base part 39 , in which a sealing element 45 in the form of a sealing ring is accommodated, which seals radially towards the cover component 40 .

[0060] In this variant, the fluid chamber 10 surrounding the spindle housing 2 is also axially delimited and sealed on the suction side by these sealing structures. In this variant, the fluid chamber 10 extends over the entire length of the spindle housing 2 because, as described with respect to the previous embodiment, the fluid escapes axially at the axially open pressure-side end of the spindle housing 2, is deflected again by the deflection chamber 14, and is directed back into the fluid chamber 10. As described above, the deflection chamber 14 can be formed directly on the corresponding bottom wall of the motor housing 23 or on the plate-like intermediate component 33.

[0061] In any case, a corresponding pressure is built up in the fluid chamber 10, which acts radially on all sides of the spindle housing 2. Figure 7 As shown, the fluid chamber 10 is also connected to the outlet connection 9 here.

Claims

1. A screw pump comprising a spindle housing (2), in which a drive spindle (3) and at least one driven spindle (4) meshing with the drive spindle are accommodated in a spindle bore (28), and the screw pump comprises an outer housing (5) surrounding the spindle housing (2), on which an axial inlet connection (6) and a radial outlet connection (9) are provided, wherein the spindle housing (2) has an axial flow channel for a fluid conveyed through the spindle housing (2) via the drive spindle and the driven spindle (3, 4). The outer shell (5) is provided with an axial fluid outlet, the axial fluid outlet is connected to a fluid chamber (10) extending 360 degrees and constructed between the main shaft housing (2) and the outer shell (5), and the fluid chamber is in turn connected to the radial outlet joint (9). An intermediate component (33) is placed on the outer shell (5), and the intermediate component is suitable for connecting to a drive motor (11), wherein one or more deflection chambers (14) are constructed on the intermediate component (33) for deflecting the fluid from the axial fluid outlet of the main shaft housing (2) to the fluid chamber (10).

2. The screw pump according to claim 1, characterized in that The fluid chamber (10) extends over at least half the length of the spindle bore (28).

3. The screw pump according to claim 1, characterized in that The fluid chamber (10) is axially delimited by two radial flanges (16, 19), wherein one radial flange (19) has a plurality of axial through-holes (15), through which the fluid chamber (10) is connected to an axial fluid outlet of the spindle housing (2).

4. The screw pump according to claim 1, characterized in that The fluid chamber (10) is axially limited by a radial flange (19) and a cover member (40), wherein the radial flange has a plurality of axial through holes (15), and the fluid chamber (10) is connected to an axial fluid outlet of the spindle housing (2) through the axial through holes.

5. The screw pump according to claim 1, characterized in that The deflection cavity (14) is an annular groove or a cylindrical depression, and is circular in the area of ​​the groove or depression bottom.

6. The screw pump according to claim 1, characterized in that The fluid chamber (10) is sealed relative to the outer housing (5) by one or more sealing elements.

7. The screw pump according to claim 3, characterized in that A first sealing element (18) is accommodated in an accommodating groove (25) on a radial flange (16) of the spindle housing (2) or the outer housing (5) adjacent to the axial inlet connection (6) and seals the spindle housing (2) relative to the outer housing (5), and a second sealing element (20) is accommodated in an accommodating groove (36) of the intermediate component (33) and seals the intermediate component (33) toward the outer housing (5).

8. The screw pump according to claim 4, characterized in that A third sealing element (43) is accommodated in an accommodating groove (42) on the spindle housing (2) or the top cover member (40) and seals the spindle housing (2) toward the top cover member (40), a fourth sealing element (45) is accommodated in an accommodating groove (44) on the outer shell (5) or the top cover member (40) and seals the outer shell (5) toward the top cover member (40), and a second sealing element (20) is accommodated in an accommodating groove (36) of the intermediate member (33) or the outer shell (5) and seals the intermediate member (33) toward the outer shell (5).

9. The screw pump according to claim 4, characterized in that The spindle housing (2), the outer housing (5), the intermediate component (33) and / or the top cover component (40) are made of plastic.

10. The screw pump according to claim 1, characterized in that A drive motor (11) is provided, which is coupled to the drive spindle (3) via a drive shaft (12). The drive motor is implemented as a dry rotor, wherein the drive shaft (12) is radially sealed by a shaft sealing ring, or the drive motor is implemented as a wet rotor, wherein a portion of the fluid escaping axially from the spindle housing (2) flows along the drive shaft (12) into the drive motor (11).

11. The screw pump according to claim 1, characterized in that A central driving spindle (3) and two driven spindles (4) are arranged on both sides of the driving spindle.

12. The screw pump according to claim 1, characterized in that The axial inlet connection (6) is arranged in a manner aligned with the central axis of a spindle group comprising the driving spindle (3) and one or two driven spindles (4).

13. A screw pump having a spindle housing (2), in which a drive spindle (3) and at least one driven spindle (4) meshing with the drive spindle are accommodated in a spindle bore (28), and the screw pump has an outer housing (5) surrounding the spindle housing (2), an axial inlet connection (6) and a radial outlet connection (9) being provided on the outer housing, wherein the spindle housing (2) has an axial fluid outlet for a fluid conveyed through the spindle housing (2) via the drive spindle and the driven spindle (3, 4), the axial fluid outlet being connected to a fluid chamber (10) extending 360° constructed between the spindle housing (2) and the outer housing (5), the fluid chamber in turn being connected to the radial outlet connection (9), and one or more deflection chambers (14) being provided on a motor housing (23) of a drive motor (11) mounted on the outer housing (5), which deflect the fluid from the axial fluid outlet of the spindle housing (2) to the fluid chamber (10).

14. The screw pump according to claim 13, characterized in that The fluid chamber (10) extends over at least half the length of the spindle bore (28).

15. The screw pump according to claim 13, characterized in that The fluid chamber (10) is axially delimited by two radial flanges (16, 19), wherein one radial flange (19) has a plurality of axial through-holes (15), through which the fluid chamber (10) is connected to an axial fluid outlet of the spindle housing (2).

16. The screw pump according to claim 13, characterized in that The fluid chamber (10) is axially limited by a radial flange (19) and a cover member (40), wherein the radial flange has a plurality of axial through holes (15), and the fluid chamber (10) is connected to an axial fluid outlet of the spindle housing (2) through the axial through holes.

17. The screw pump according to claim 13, characterized in that The deflection cavity (14) is an annular groove or a cylindrical depression, and is circular in the area of ​​the groove or depression bottom.

18. The screw pump according to claim 13, characterized in that The fluid chamber (10) is sealed relative to the outer housing (5) by one or more sealing elements.

19. The screw pump according to claim 15, characterized in that A first sealing element (18) is accommodated in an accommodating groove (25) on a radial flange (16) of the spindle housing (2) or the outer housing (5) adjacent to the axial inlet connection (6) and seals the spindle housing (2) relative to the outer housing (5), and a second sealing element (20) is accommodated in an accommodating groove (32) of the motor housing (23) of the drive motor (11) and seals the motor housing (23) toward the outer housing (5).

20. The screw pump according to claim 16, characterized in that A third sealing element (43) is accommodated in an accommodating groove (42) on the spindle housing (2) or the top cover member (40) and seals the spindle housing (2) toward the top cover member (40), a fourth sealing element (45) is accommodated in an accommodating groove (44) on the outer housing (5) or the top cover member (40) and seals the outer housing (5) toward the top cover member (40), and a second sealing element (20) is accommodated in an accommodating groove (32) of the motor housing (23) of the drive motor (11) and seals the motor housing (23) toward the outer housing (5).

21. The screw pump according to claim 16, characterized in that The spindle housing (2), the outer housing (5) and / or the cover component (40) are made of plastic.

22. The screw pump according to claim 13, characterized in that A drive motor (11) is provided, which is coupled to the drive spindle (3) via a drive shaft (12). The drive motor is implemented as a dry rotor, wherein the drive shaft (12) is radially sealed by a shaft sealing ring, or the drive motor is implemented as a wet rotor, wherein a portion of the fluid escaping axially from the spindle housing (2) flows along the drive shaft (12) into the drive motor (11).

23. The screw pump according to claim 13, characterized in that A central driving spindle (3) and two driven spindles (4) are arranged on both sides of the driving spindle.

24. The screw pump according to claim 13, characterized in that The axial inlet connection (6) is arranged in a manner aligned with the central axis of a spindle group comprising the driving spindle (3) and one or two driven spindles (4).

25. Use of a screw pump (1) according to any one of the preceding claims for pumping a working fluid in a motor vehicle.

26. The use according to claim 25, characterized in that The screw pump (1) serves as a coolant pump.

27. The use according to claim 25, characterized in that The screw pump (1) is used to transport a coolant for cooling the energy storage device.

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