Thermoregulating pump with structured rotor core

Abstract

To provide a pump with improved efficiency by avoiding or reducing leakage magnetic flux from a rotor.SOLUTION: A pump includes a stator and a rotor. The rotor includes a rotor body and a rotor block 4, and is supported for rotation about a rotation axis. The rotor block 4 has a metallic rotor core 22 and a magnet 13. The rotor core 22 has a plurality of holes 26 in cross section. The rotor core 22 has a plurality of grooves 32 and a plurality of protrusions 33 on a radially inner wall 34 of the rotor core in cross section.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a pump for driving a fluid, preferably a temperature control medium, in particular for use in a vehicle, in particular for temperature control of a drive battery in an electric vehicle, the pump comprising a stator and a rotor, the rotor having a rotor body and a rotor block and being rotatably supported about a rotation axis, the rotor block having a metallic rotor core and magnets, the rotor core having a plurality of holes, viewed in cross section. [Background technology]

[0002] Patent Document 1 discloses an electric pump for cooling a vehicle having an internal combustion engine. The pump includes a stator and a rotor, the rotor itself including a rotor body, two rotary bearings, and a rotor block. The rotor block includes a rotor core made of a plurality of laminated electric steel plates and a plurality of magnets, the magnets being attached to the radially outer surface of the rotor core. The electric steel plates have a number of holes, which are used on the one hand to reduce the weight of the rotor core or rotor block or rotor, and on the other hand to guide the magnetic field lines in the rotor core.

[0003] The energy transition and the mobility shift require the expansion of new technologies, including in particular electric vehicles with a traction battery and an electric motor. The traction battery achieves maximum efficiency at a temperature of around 20°C and must be heated or cooled depending on the situation. Heating is especially expedient immediately after starting in winter, whereas cooling is considered especially after the vehicle has already been running for some time. In this respect, the thermal management of the powertrain in electric vehicles differs from combustion-based vehicles, especially in cold weather. After all, the entire component chain of the thermal management in electric vehicles (pipes, quick connectors, pumps, battery casing, etc.) must additionally be designed to work in cold weather and also without the assistance of running wind. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent No. 3121937 Summary of the Invention [Problem to be solved by the invention]

[0005] This means that a relatively large flow rate of temperature control fluid in an electric vehicle is required all year round. As a result, the pump must be designed with a correspondingly high performance. The problem underlying the present invention is therefore to design a pump with a higher performance for thermal management. Preferably, the problem underlying the present invention is to increase this performance without sacrificing the effort or costs required for production or the amount of material used. [Means for solving the problem]

[0006] The above-mentioned problem or problems are solved by a pump for driving a fluid, preferably a temperature control medium, in particular for use in a vehicle, in particular for temperature control of a drive battery in an electric vehicle, the pump comprising a stator and a rotor, the rotor having a rotor body and a rotor block and being rotatably supported about a rotation axis, the rotor block having a metallic rotor core and a magnet, the rotor core having, in cross section, a plurality of holes and the rotor core having, in cross section, a plurality of grooves and a plurality of protrusions on its radially inner wall.

[0007] The invention is based primarily on the recognition that the rotor, and in particular the rotor core, can be further improved in order to increase the performance of the pump. It has been found that the magnetic field lines tend to deviate from the intended radially outer region of the rotor core in a significant number of rotational positions of the rotor relative to the stator. In this case, the magnetic field lines may also extend partially in the rotor core between the radially inner surface of the bore and the radially inner surface of the rotor core. This scattering of the magnetic field lines increases the magnetic resistance and reduces the motor efficiency. Flux leakage is particularly noticeable in electric pumps, since the distance between the stator and the rotor block is relatively large due to the partition wall, the block casing and the annular gap provided for the secondary flow, which intensifies the flux leakage.

[0008] The present invention is based in particular on the recognition that avoiding or reducing this leakage flux increases the efficiency or performance of the pump. It has been found that grooves on the radially inner surface of the rotor core reduce the leakage flux between the holes and the radially inner surface of the rotor core. This causes the magnetic field lines to be more strongly concentrated in the radially outer region of the rotor core, which increases the efficiency or performance of the pump. As a result, the problem mentioned at the beginning is solved.

[0009] Preferably, the axis of rotation A defines axial, radial and / or tangential or circumferential directions. The expression "radially inward" means the radial direction towards the axis of rotation A. The term "axially inward" means the axial direction corresponding to the direction of the fluid flow in the suction. In particular, "axially inward" means the axial direction from the pump wheel towards the rotor block. The axially outermost section of the pump is preferably at the same time the uppermost section of the pump. The end of the pump axially opposite to the uppermost section is the lowermost section or the lower end. Viewed in a plan view, the tangential direction may extend clockwise or counterclockwise. The rotor preferably rotates clockwise.

[0010] The magnets are preferably permanent magnets. The rotor or rotor block preferably comprises at least 6 or 8 magnets in cross section. Advantageously, the rotor or rotor block comprises at most 20, 16 or 14 magnets in cross section. Advantageously, the rotor core is arc-shaped at least in some sections along the circumference of the rotor core. Preferably, the rotor core comprises magnet spaces on the radially outer surface of the rotor core, with one magnet being arranged in each magnet space. Very preferably, the magnets are formed arc-shaped on the radially inner surface of the magnets and / or on the radially outer surface of the magnets, in plan or cross section. It is advantageous if the magnet spaces have an arc-shaped contour in plan or cross section and in particular have a surface complementary to the magnets.

[0011] Very preferably, the rotor core comprises a number of plates, in particular rotor sheet metals, stacked one on top of the other. The rotor sheet metals are preferably electrical steel sheets. Very preferably, the rotor core comprises at least 10, 15 or 20 plates or rotor sheet metals. It is advantageous if the rotor core comprises a maximum of 50, 40 or 30 rotor sheet metals. Expediently, the plates or rotor sheet metals are aligned in a row over a complete circumference. The plates / rotor sheet metals can be joined to one another by stamping lamination or by adhesive coating to form the rotor core. It is advantageous if the rotor sheet metals are provided with an insulating coating.

[0012] According to a particularly preferred embodiment, the pump is configured such that the fluid flows around the block casing of the rotor body during pump operation. This allows a secondary flow to flow into the wheel chamber or from said wheel chamber into the drive chamber / said drive chamber. Via a return guide passage or a return guide passage, the secondary flow of fluid can then flow back through the rotor in an axially outward direction into the wheel chamber. The secondary flow thereby removes heat from the stator, the rotor and / or the substrate, so that the pump can be cooled and run more efficiently as a whole.

[0013] According to a particularly preferred embodiment, the rotor body or the block casing comprises plastic. The rotor body or the block casing is advantageously formed in one piece, preferably integrally. If the rotor body is produced in one piece, for example by injection molding or insert molding, the rotor body is of a lightweight and nevertheless very stable construction. This allows a great many details in the rotor body to be realized. These details are in particular the return guide channels and the vanes. As a result, the rotor body can be produced advantageously, despite having a great many technical details. At the same time, the rotor body is distinguished by a correspondingly high robustness in the case of a one-piece construction, which allows it to be constructed with relatively thin walls. This also applies to the block casing.

[0014] The rotor expediently has a pump wheel and / or a shaft. The pump wheel advantageously has a wheel disk and / or vanes and / or a wheel cover. The wheel disk is expediently arranged axially inwardly of the vanes. The vanes preferably define vane passages between themselves in a plan view. The vanes can be covered axially outwardly by a wheel cover. The wheel cover can be attached to the vanes, in particular by plugging or welding.

[0015] Very preferably, the rotor body comprises the blades and / or the wheel discs and / or the shaft. The shaft preferably comprises the drive section and / or the coupling section. Expediently, the drive section and the block casing overlap in the axial direction. According to a particularly preferred embodiment, the block casing, the drive section, the coupling section, the wheel discs and / or the blades are integrally connected to one another and preferably form the rotor body.

[0016] According to a preferred embodiment, the grooves alternate tangentially with the protrusions. The tangential extension of the grooves can be equal to the tangential extension of the protrusions. Preferably, the inner wall of the rotor core is formed only from the grooves and the protrusions. This results in the largest possible area of ​​the inner wall in the radial direction contributing to the guidance of the magnetic field lines. The grooves and the protrusions preferably extend along at least 50 or 60 or 70 or 80 or 90 or 100% of the axial extension of the rotor core or rotor block. Advantageously, the upper cover plate, the lower cover plate, the holder plate and / or the block plate have the grooves and the protrusions. This results in the largest possible area of ​​the inner wall in the radial direction contributing to the guidance of the magnetic field lines.

[0017] Very particularly preferably, the holes are offset relative to the grooves in the tangential direction. Preferably, the holes and the grooves alternate with one another in the tangential direction. Very particularly preferably, the holes and the grooves do not overlap in the tangential direction. Advantageously, as viewed in a cross section of the rotor block, free spaces are present between the magnets in the tangential direction. Preferably, at least one of the free spaces is assigned to a groove in the tangential direction. Advantageously, at least one of the free spaces overlaps in the tangential direction with the assigned groove. Very particularly preferably, the at least one free space and the groove assigned to it are formed axisymmetrically with respect to a common radial line. This allows for the guidance or spatial regulation of the magnetic field lines directed radially inwards, so that the magnetic field is kept compact and the magnetic resistance is kept low.

[0018] According to a particularly preferred embodiment, the number of magnets, in the cross section of the rotor core, is equal to the number of holes, grooves and / or protrusions. This causes a targeted influence of the magnetic field lines for each magnet. If each magnet is assigned a hole, each magnet can be assisted by the hole in the same way in guiding the magnetic field lines. As a result, with each magnet, practically the same drive of the rotor is achieved, which achieves the quietest possible operation.

[0019] Preferably, at least one of the magnets of the rotor block, preferably each of the magnets, is assigned one of the holes and / or one of the protrusions, in particular in the tangential direction, as viewed in the cross section of the rotor core. Advantageously, at least one magnet overlaps in the tangential direction with the assigned hole and / or the assigned protrusion. Preferably, at least one magnet and / or the hole assigned to this magnet and / or the protrusion assigned to this magnet are formed axisymmetrically with respect to a common radial line. The axisymmetrical arrangement ensures that the magnetic field is always formed as similarly as possible when moving through the rotor block or rotor core, so that a high level of running quietness can be achieved.

[0020] Advantageously, at least one of the holes and one protrusion tangentially assigned to the at least one hole overlap in the tangential direction. Preferably, all of the holes overlap in the tangential direction with the protrusion respectively assigned to the hole. Preferably, at least one hole and the protrusion assigned to this hole are formed axisymmetrically with respect to a common radial line. Preferably, the tangential extension of the protrusion corresponds to at least 50, 60, 70, 80 or 90% of the tangential extension of the hole. Advantageously, the radial extension RN of the groove is equal to the radial extension of the protrusion. Preferably, the cross-sectional area of ​​the protrusion formed by the radial extension of the protrusion and the tangential extension of the protrusion corresponds to at least 50, 60, 70, 80 or 90% of the cross-sectional area of ​​the assigned hole. This results in a relatively even distribution of rotor core material around the circumference, thereby reducing electromagnetic and mechanical non-uniformities and enhancing quieter operation.

[0021] Ideally, two, preferably all, of the magnets of the rotor block have the same shape and / or the same magnetic properties and / or the same radial position, as viewed in the cross section of the rotor core. Advantageously, two, preferably all, of the holes of the rotor core have the same shape and / or the same radial position. Preferably, two, preferably all, of the protrusions of the inner wall of the rotor core have the same shape and / or the same radial position. Preferably, two, preferably all, of the grooves of the inner wall of the rotor core have the same shape and / or the same radial position. This allows for a uniform or repeating configuration in the tangential direction of the rotor block, whereby a high running quietness is achieved.

[0022] Preferably, the radial extension RL of the hole and the radial extension RKV of the rotor core at the circumferential position of one of the protrusions have a ratio RL / RKV of at most 0.80, 0.70, 0.60, 0.55 or 0.50. This results in the hole being formed relatively flat in relation to the radial extension of the rotor core. This allows more space to be left for the magnetic field lines in the radially outer region of the rotor core, so that the magnetic field lines can be well restricted in the radially outer region. Preferably, the outer radius AR of the rotor core and the radial extension RKN of the rotor core at the circumferential position of one of the grooves have a ratio AR / RKN of at least 2.0, 2.3, 2.5, 2.7, 3.0 or 3.2. This keeps the rotor core relatively thin or narrow in the radial direction in relation to the outer radius AR or diameter of the rotor core. In this case, in particular, the ratio AR / RKN can become larger as the ratio RL / RKV becomes smaller.

[0023] According to a preferred embodiment, at least one of the grooves and / or at least one of the protrusions has a polygonal, preferably quadrangular, shape. Advantageously, all the grooves and / or all the protrusions have a polygonal, preferably quadrangular, shape. This relatively uniform shape in the tangential direction makes the radially acting effect of the grooves or protrusions uniform in the tangential direction. Preferably, the tangential extension of at least one groove is at least 1.5 or 2.0 or 2.5 times greater than the radial extension of the groove. Preferably, the tangential extension of at least one protrusion is at least 1.5 or 2.0 or 2.5 times greater than the radial extension of the protrusion. Thereby, the grooves or protrusions are formed elongated in the tangential direction. This allows a sufficiently pronounced effect in the tangential direction of the radial action of the protrusions or grooves, respectively.

[0024] According to a particularly preferred embodiment, at least one of the holes of the rotor core, preferably all of the holes, when viewed in cross section of the rotor core, has the shape of a polygon, in particular a pentagon. Advantageously, at least one of the holes has an apex, preferably facing radially outward. The apex is used, inter alia, for a clean separation of the magnetic field and thus for avoiding leakage fluxes. Advantageously, at least one of the holes has a radially outer surface. Advantageously, the apex of the hole constitutes the radially outermost point of this radially outer surface of the hole. Preferably, at least one of the holes has two tangential outer surfaces. Advantageously, at least one of the holes has a radially inner surface. This radially inner surface of the hole expediently connects both tangential outer surfaces of the hole.

[0025] According to a particularly preferred embodiment, at least one, preferably all, of the holes in the rotor core are filled with air. Very particularly preferably, the rotor core has an upper and / or a lower cover plate. The upper and / or the lower cover plate preferably does not have any holes. The upper and / or the lower cover plate is preferably formed in such a way that during the insert molding process, the plastic does not flow into the holes in the rotor core. This results in a better guidance of the magnetic field lines. The holes preferably extend over at least 50 or 60 or 70 or 80 or 90% of the axial extension of the rotor core or rotor block.

[0026] It is advantageous for at least one of the grooves to have a radial extension RN, the ratio RN / RKN preferably reaching at least 0.1 or 0.14 or 0.17. This achieves a sufficiently strong restriction of the magnetic field lines. The ratio RN / RKN is advantageously at most 0.60 or 0.50 or 0.40 or 0.30 or 0.25. This allows the magnetic field lines not to be restricted or distorted too strongly, so that the magnetic resistance is not increased.

[0027] The invention will now be described on the basis of an embodiment with the aid of four figures, which are schematic diagrams. [Brief description of the drawings]

[0028] [Figure 1] 1 is a vertical cross-sectional view of a pump according to the present invention. [Diagram 2] FIG. 2 is a simplified perspective view of a rotor block of the pump shown in FIG. [Diagram 3] FIG. 3 is a simplified cross-sectional view of the rotor block shown in FIGS. 1 and 2. [Figure 4] FIG. 4 is a partial view of the rotor block shown in FIG. 3, but additionally together with a stator in a simplified form. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The pump according to the invention expediently has an inlet 8 and an outlet 9, which is shown in dashed lines in the selected longitudinal section. The pump comprises a rotor 2, which expediently has a pump wheel 6. The pump comprises a stator 1, which drives a rotor block 4. The rotor block 4 is a component of the rotor 2. The rotor 2 expediently has a shaft 7, which transmits the torque of the rotor block 4 to the pump wheel 6. The pump wheel 6 preferably has vanes 19 and / or a wheel disc 31.

[0030] The vanes 19 displace the fluid entering through the suction port 8 radially outwards, where it is expediently collected over an approximately complete circumference by the collecting passage 28, which expediently opens into the discharge port 9. In the present embodiment, the fluid flow from the suction port 8 through the pump wheel 6 into the collecting passage 28 and up to the discharge port 9 is the main flow of the fluid. The chain of elements 8, 6, 28, 9 thereby forms the main flow path.

[0031] Preferably, the pump comprises a partition wall 16 and a casing 15. Very preferably, the partition wall 16 separates the space inside the casing 15 into a dry area and a wet area. Preferably, the stator 1 is arranged in the dry area. Advantageously, the pump comprises a base plate 18 for controlling the pump operation, in particular the stator 1. Preferably, the base plate 18 is present in the dry area of ​​the pump.

[0032] The wet area of ​​the pump preferably has an inlet 8 and an outlet 9. Preferably, the wet area has a wheel chamber 10 in which the pump wheel 6 is arranged. Expediently, in the axially inward direction or downwards as viewed in longitudinal section, the wheel chamber 10 is connected to a drive chamber 11, which is advantageously formed by a partition wall 16. Very preferably, the rotor block 4 is arranged in the drive chamber 11.

[0033] Advantageously, between the partition wall 16 and the wheel disc 31 or pump wheel 6 there is a surrounding gap, through which the fluid can flow from the wheel chamber 10 into the drive chamber 11. Very preferably, the rotor 2 has at least one return guide passage 12, preferably several return guide passages 12, which / these extend in the rotor 2 approximately axially and connect the lowermost region of the drive chamber 11 to the wheel chamber 10.

[0034] Due to the pressure difference generated by the pump wheel 6 between the radially inner and the radially outer side, a small part of the fluid, the secondary flow, flows from the wheel chamber 10 into the drive chamber 11 and from there through the rotor block 4 into the lowermost region of the drive chamber 11. The secondary flow then enters the lower inlet of the return guide passage or passages 12, flows through the rotor 2 and finally leaves from the top in the radially inner region of the wheel chamber 10. There, the secondary flow mixes with the main flow.

[0035] The secondary flow has the advantage that the heat of the stator 1, the rotor block 4 and the base plate 18 can be carried away so that the pump as a whole can work more efficiently, but at the same time this means that the rotor block 4 is located in a wet area, which can impose corresponding technical demands on the rotor block 4 or the rotor 2.

[0036] The rotor 2 in this embodiment has a rotor body 3, which preferably comprises plastic. The rotor body 3 can have the blades 19, the wheel discs 31, the shaft 7, the return guide passages 12 and / or the block casing 17. In this embodiment, the rotor body 3 is produced by injection molding or insert molding of the rotor block 4. The block casing 17 in this embodiment completely surrounds the rotor block 4 with the magnets 13 and the rotor core 22. This ensures very good protection of the rotor block 4 from secondary flows. At the same time, insert molding makes it possible to form a very smooth outer surface of the rotor 2 or rotor body 3, so that the rotor 2 rotating in the fluid has good hydrodynamic properties.

[0037] In the present embodiment, an axle 23 is supported in a non-rotatable manner in the bottom of the partition wall 16. The axle 23 defines a rotation axis A about which the rotor 2 rotates. The rotor 2 can advantageously have a rotation bearing 5, which can be optimized in terms of tribology and can in particular comprise graphite. The pump preferably comprises an axle holder 24, which in the present embodiment is pressed into the spider receiver. The upper axial end face of the rotation bearing 5 therefore rotates against the lower axial end face of the axle holder 24. Very preferably, the rotor body 3 is formed by insert molding of the rotation bearing 5 and the rotor block 4. The rotor 2 can have a rotor cover 25, which is preferably snapped onto the vanes 19. A rotor cap can be arranged at the lower end of the motor 2, which is preferably attached to the rotor 2 only after the insert molding.

[0038] In this embodiment, the block casing 17 is integrally connected to the shaft 7 of the rotor 2 or rotor body 3, and preferably to the wheel discs 31 and / or vanes 19 of the pump wheel. This integral connection is preferably achieved by insert molding of the rotor block 4.

[0039] FIG. 2 shows the rotor block 4 or rotor core 22 in a simplified manner, since the grooves on the radially inner wall of the rotor core 22 are not shown here and are missing. These grooves 32 and projections 33 are however visible in FIGS. 3 and 4. The grooves 32 and projections 33 particularly preferably extend along the entire axial length of the rotor block 4 or rotor core 22. Advantageously, the upper cover plate 27a, the lower cover plate 27b, the holder plate 21 and / or the blocking plate 20 have the grooves 32 and projections 33.

[0040] The magnets 13 are preferably arranged on the radially outer surface of the rotor core 22 (see FIG. 2). For this purpose, the rotor block 4 has a magnet holder 14, which holds the magnets 13 in the rotor core 22. By holding the magnets 13 in the rotor core 22, the rotor block 4 is sufficiently stable overall for subsequent insert molding.

[0041] The rotor core 22 in this embodiment is made up of 25 plates 20, 21, 27 stacked one on top of the other. The plates 20, 21, 27 are preferably electrical steel sheets. The electrical steel sheets are suitably provided with an insulating coating, so that eddy currents, especially in the axial direction, are avoided. The plates 20, 21, 27 of this starting example can be joined to one another by stamping or by adhesive coating to form the rotor core 22 in one piece. In this embodiment, the rotor core 22 has exactly 22 block plates 20 made of electrical steel sheets, which block plates 20 have the same shape.

[0042] The rotor block 4 in this embodiment has a total of ten magnets 13, which are preferably formed as permanent magnets. For better illustration, however, only five magnets 13 are shown in FIG. 2. Preferably, the magnets 13 are formed in the shape of a circular arc on their radially inner side and / or on their radially outer side, as viewed in the plane of the rotor block. Advantageously, on the radially outer side of the rotor core 22, the rotor core 22 has in this embodiment ten magnet spaces 30, which are assigned to one magnet 13 each. Preferably, the magnet holders 14 or magnet spaces 30 or magnets 13 are equally spaced apart from one another in the tangential direction.

[0043] In the present embodiment, the lowest plate is formed as a lower cover plate 27b. The lower cover plate may comprise electrical steel or plastic. The lower cover plate 27b preferably has a number of axial holders 29, in the present embodiment ten. Expediently, each axial holder 29 is assigned to one magnet space 30. The axial holders 29 are preferably formed as axial stops, so that the magnets 13 are securely held in the rotor core 22 axially downwards. The rotor core may preferably have an upper cover plate 27a, which is preferably formed as a blocking plate 20. The lower cover plate 27b can be above the upper cover plate 27a after assembly of the pump, so that the directional orientation of the plate can differ from the above-mentioned directional orientation of the pump.

[0044] According to a particularly preferred embodiment, the rotor core 22 has two holder plates 21, or an upper holder plate 21 and a lower holder plate 21. Both holder plates 21 in this embodiment preferably have a number of magnet holders 14, preferably one each, equal to the number of magnets. The magnet holders 14 are preferably an integral part of the holder plate / s. The magnet holders 14 or the holder plate / s are preferably produced by stamping. It is advantageous if the holder plates 21 are arranged in the upper half or in the upper third or in the upper quarter of the rotor core 22. Expediently, the lower holder plate 21 is arranged in the lower half or in the lower third or in the lower quarter of the rotor core 22.

[0045] Figure 3 shows the rotor block 4 in a simplified plan view, since the upper cover plate 27a has been omitted to expose the uppermost block plate 20. Figure 3 is also simplified compared to Figure 2 in that it lacks the grooves in the radial outer wall of the rotor core 22. Figure 3 is also simplified compared to Figure 2 in that it shows only one magnet holder 14.

[0046] The rotor core 22 has grooves 32 and protrusions 33 on a radially inner wall 34 of the rotor core 22 according to the invention. The grooves 32 are expediently alternated with the protrusions 33 in the tangential direction. In the present embodiment, the tangential extension of the grooves 32 is equal to the tangential extension of the protrusions 33. Advantageously, the rotor core 22 is formed such that the grooves 32 and the protrusions 33 complement each other to form the inner wall 34 of the rotor core 22. Preferably, the inner wall 34 of the rotor core 22 is formed only from the grooves 32 and the protrusions 33. The tangential extension of one of the grooves 32 can be equal to the tangential extension of one adjacent protrusion 33.

[0047] According to the invention, the rotor core 22 has holes 26. Advantageously, the blocking plates and / or the holder plates have the holes 26. Preferably, the upper cover plate 27a and / or the lower cover plate 27b have no holes. The holes 26 are preferably filled with air. This is achieved advantageously via the upper cover plate 27a and the lower cover plate 27b, which are both holeless and cover the holes 26 of the other plates 20, 21. Thereby, the holes 26 are not filled with plastic during the insert molding process.

[0048] Very preferably, the holes 26 extend in the axial direction over at least 50, 60, 70, 80 or 90% of the axial extension of the magnet 13. It is advantageous for the grooves 32 to extend over at least 50, 60, 70, 80, 90 or 95% of the axial extension of the magnet 13. Very preferably, the upper cover plate 27a and / or the lower cover plate 27b have the grooves 32 and the protrusions 33 on the radially inner surface of the upper cover plate 27a and / or the lower cover plate 27b.

[0049] Preferably, the number of magnets 13 is equal to the number of holes 26, grooves 32 and / or protrusions 33. Advantageously, as viewed in a cross section of the rotor core 22, at least one of the magnets 13, preferably each of the magnets 13, is assigned one of the holes 26 and / or one of the protrusions 33, in particular in the tangential direction. Preferably, at least one magnet 13 overlaps in the tangential direction with the assigned hole 26 and / or the assigned protrusion 33. In this embodiment, each one of the holes 26 and each one of the protrusions 33 overlap in the tangential direction. Preferably, at least one magnet 13 and / or the hole 26 assigned to this magnet 13 and / or the protrusion 33 assigned to this magnet 13 are formed axisymmetrically with respect to a common radial line.

[0050] Advantageously, the holes 26 are offset in the tangential direction with respect to the grooves 32. Very preferably, the holes 26 and the grooves 32 alternate with one another in the tangential direction. Particularly preferably, the holes 26 and the grooves 32 do not overlap in the tangential direction. Advantageously, the free spaces between the magnets 13 in the tangential direction overlap the grooves 32 in the tangential direction. Very preferably, one of the free spaces between the magnets and one of the grooves 32 which tangentially overlaps this free space are formed axisymmetrically with respect to one common radius.

[0051] In this embodiment, at least one hole 26, preferably all holes 26, are formed in a polygonal shape, preferably at least in a triangle, particularly preferably in a pentagonal shape. At least one hole 26 preferably has a vertex 26a, which preferably faces radially outward. Very preferably, at least one hole 26 has a radially outer surface 26b. Preferably, the vertex 26a constitutes the radially outermost point of this radially outer surface 26b. In this embodiment, this radially outer surface 26b is formed by two straight lines approaching each other, which preferably run in the tangential and radial directions, respectively. Preferably, at least one hole 26 has two tangential outer surfaces 26c. Advantageously, at least one hole 26 has a radially inner surface 26d. This radially inner surface 26d expediently connects both tangential outer surfaces 26c.

[0052] At least one hole 26, preferably all holes 26, are preferably formed relatively flat. Preferably, the tangential extension TL of the at least one hole 26 is greater than the radial extension RL of the holes 26. The rotor core 22 (K) has a radial (R) extension RKV at the protrusions 33 (V). Highly preferably, the ratio RL / RKV is at most 0.70 or 0.65 or 0.50. In this embodiment, the ratio RL / RKV may be about 0.40.

[0053] The rotor core is advantageously made relatively narrow in the radial direction, in particular in the region of the grooves 32. The rotor core 22(K) has a radial (R) extension RKN at the location of the grooves 32(N). The rotor core 22 has an outer radius AR. Preferably, the outer radius AR is the arithmetic mean value of all the outer radii over the entire circumference. Very preferably, the ratio AR / RKN is at least 2.3 or 2.7 or 3.0. In the present embodiment, this ratio may be 3.5. The grooves 32(N) have a radial (R) extension RN. The ratio RN / RKN preferably amounts to at least 0.1 or 0.14 or 0.17, in the present embodiment it amounts to about 0.21.

[0054] Figure 4 shows a partial view of the rotor block 4 shown in Figure 3, which is additionally surrounded by a stator 1, which is shown in a simplified manner in comparison with Figure 3. For the sake of clarity, in particular the stator windings have been omitted in Figure 4, as well as the partition wall 16. The stator 1 shown here thus corresponds essentially to a cross section of the stator core or to the plane of one of the plates of the stator core. For the sake of clarity, the magnet holders 14 and the grooves on the radially outer surface of the rotor core 22 have also been omitted in Figure 4.

[0055] The stator 1 or stator core has a stator ring 35 and a number of inwardly projecting poles 36. The poles 36 each have, expediently, a pole core 37 and a pole shoe 38. Stator windings (not shown) are wound around the pole cores 37, in particular in the tangential direction, and are held in the radial direction by the pole shoes 38 and the stator ring 35.

[0056] During operation of the pump, magnetic field lines 39a, 39b are formed as shown in Figure 4. The magnetic field lines 39a, 39b form a closed circle through the first pole core 37, the stator ring 35, the second pole core 37, the first magnet 13, the rotor core 22, and the second magnet 13. In this case, the lines 39a symbolically represent the outer magnetic field lines, while the lines 39b represent the inner magnetic field lines.

[0057] 4 it can be seen that the hole 26, preferably the air-filled hole 26, influences the extension of the magnetic field lines 39a, 39b, in particular the outer magnetic field line 39a, so that the outer magnetic field line 39a extends along the radial outer surface 26b and the tangential outer surface 26c of the hole 26. The outer magnetic field line 39a is also restricted radially inwards by the groove 32 in particular.

[0058] As a result, the magnetic field lines 39a, 39b are concentrated in the smallest possible outer area in the rotor block 4 or rotor core 22, whereby a correspondingly lower magnetic resistance is achieved. In particular, by means of the holes 26 and the grooves 32, the magnetic field lines are concentrated in the radially outer area of ​​the rotor core 22, and leakage flux is further avoided. This is particularly advantageous for pumps with partitions and secondary flows, since in such pumps the distance between the stator 1 and the rotor block 4 is relatively large and, as a result, the tendency for divergence of the magnetic field lines and leakage flux is also relatively large. [Explanation of symbols]

[0059] A Rotation axis 1 Stator 2 Rotors 3 Rotor body 4 Rotor Block 5 Rotary bearing 6 Pump Wheel 7 Shaft 8 Intake port 9 Outlet 10 Wheel Chamber 11 Drive chamber 12 Return guide passage 13. Magnet 14 Magnet holder 15 Casing 16 Partition Wall 17 2,3 block casing 18 Substrate 19 6 Feathers 20 Block Plate 21 Holder plate 22 Rotor core 23 Axle 24 Axle holder 25 2 Wheel Cover 26 holes 27a Upper cover plate 27b Lower cover plate 28 Gathering aisle 29 Axial holder 30 Magnet Space 31 Wheel disc 32 Groove 33 Protrusion 34 Inner wall 35 Stator ring 36 Paul 37 Pole Core 38 Pole shoe 39a Outer magnetic field lines 39b Inner magnetic field lines AR outer radius RN Groove radial extension RL Radial extension of hole RKN Radial extension of rotor core at groove location RKV radial extension of the rotor core at the location of the protrusion TL Tangential extension of hole

Claims

1. A pump for driving a fluid, preferably a temperature control medium, for use in particular in a vehicle, in particular for temperature control of a drive battery of an electric vehicle, comprising: The pump includes a stator (1) and a rotor (2). The rotor (2) has a rotor body (3) and a rotor block (4) and is supported so as to be rotatable about a rotation axis (A). The rotor block (4) has a metallic rotor core (22) and a magnet (13). The rotor core (22) has a plurality of holes (26) in cross section. In the pump, The rotor core (22) has, in cross section, a plurality of grooves (32) and a plurality of protrusions (33) on a radially inner wall (34) of the rotor core (22). A pump characterized by:

2. 2. A pump as claimed in claim 1, wherein the pump is configured such that fluid flows around a block casing (17) of the rotor body (3) during pump operation.

3. 3. A pump according to claim 1 or 2, wherein the holes (26) are offset tangentially with respect to the grooves (32), preferably the holes (26) and the grooves (32) alternate tangentially with respect to one another.

4. 4. The pump according to claim 1, wherein, in a cross-section of the rotor core (22), the number of the magnets (13) is equal to the number of the holes (26), the grooves (32) and / or the protrusions (33).

5. 5. The pump according to claim 1, wherein at least one of the holes (26) and one protrusion (33) tangentially assigned to said at least one hole (26) overlap in the tangential direction.

6. 6. The pump according to claim 1, wherein the radial extension RL of the hole (26) and the radial extension RKV of the rotor core (22) at the circumferential position of the protrusion (33) have a ratio RL / RKV of at most 0.70, 0.65 or 0.

50.

7. 7. The pump according to any one of the preceding claims, wherein at least one of the grooves (32) and / or at least one of the protrusions (33) presents a polygonal, preferably quadrangular, shape.

8. A pump according to any one of the preceding claims, wherein at least one of said holes (26) presents a polygonal, preferably pentagonal, shape.

9. 9. A pump as claimed in any one of the preceding claims, wherein at least one of the holes (26) is filled with air.

10. 10. The pump according to any one of claims 1 to 9, wherein at least one of said grooves (32), and preferably all of said grooves (32), has a radial extension RN, the ratio RN / RKN amounting to at least 0.1, or 0.14, or 0.17.

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