Pump for driving fluid

Abstract

The invention relates to a pump for driving a fluid, comprising a stator (1) and a rotor (2), which comprises a rotor body (3) and a rotor module (4) and which is rotatably mounted about an axis of rotation (A), which rotor module comprises a metallic rotor core (22), which in cross section comprises a plurality of holes (26), and a plurality of magnets (13), the rotor core has a plurality of grooves (32) and a plurality of protrusions (33) on a radial inner wall (34) thereof in a cross section. According to the invention, the pump is configured to be more capable of thermal management.

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, particularly preferably for use in controlling the temperature of a power battery of an electric vehicle, the pump comprising a stator and a rotor, the rotor having a rotor body and a rotor module, and the rotor being rotatably supported around a rotation axis, the rotor module comprising a metal rotor core and a plurality of magnets, the rotor core comprising a plurality of holes in a cross section. Background Art

[0002] EP3121937B1 discloses an electric pump for cooling a vehicle with an internal combustion engine. The pump comprises a stator and a rotor, the rotor itself comprising a rotor body, two rotating bearings and a rotor module. The rotor module has a rotor core consisting of stacked silicon steel sheets and a plurality of magnets, which are fixed on the radial outer side of the rotor core. The silicon steel sheets have a plurality of holes, which are used on the one hand to reduce the weight of the rotor core or the rotor module or the rotor, and on the other hand to guide the magnetic lines of force in the rotor core.

[0003] Energy transformation and mobility transformation require the establishment of new technologies, which especially cover electric vehicles with power batteries and electric motors. Power batteries reach maximum efficiency at a temperature of about 20°C, so that the power batteries need to be heated or cooled depending on the operating conditions. Heating is especially suitable shortly after starting in winter, while cooling is only considered when the vehicle has been driving for a while. That's all, the thermal management of the drive train in electric vehicles differs from that of internal combustion engine vehicles, especially in cold seasons. Finally, the entire component chain of thermal management in electric vehicles (pipes, quick connectors, pumps, battery housings, etc.) needs to be designed to work in addition in cold seasons and therefore without driving wind support.

[0004] This means that, viewed over the entire year, a relatively large throughput of the temperature control fluid of the electric vehicle is required. Therefore, the pump needs to be designed to be correspondingly powerful. Summary of the invention

[0005] The invention is therefore based on the object of making the pump more capable with respect to heat management. Preferably, the invention is based on the object of increasing the capacity without increasing the manufacturing effort or the amount of material used.

[0006] The object is achieved by a pump for driving a fluid, preferably a temperature control medium, the pump being particularly used in a vehicle, particularly preferably used for temperature control of a power battery of an electric vehicle, the pump comprising a stator and a rotor, the rotor comprising a rotor body and a rotor module, and the rotor being rotatably supported about a rotation axis, the rotor module comprising a metallic rotor core and a plurality of magnets, the rotor core comprising a plurality of holes in a cross section, the rotor core having a plurality of grooves and a plurality of protrusions on its radial inner wall in a cross section.

[0007] The present invention is firstly based on the recognition that in order to increase the capacity of the pump, in particular the rotor and in particular the rotor core can be further improved. It has been found that the magnetic lines of force have the following tendency: in some rotational positions of the rotor relative to the stator, they leave the specified radially outer area of ​​the rotor core. The magnetic lines of force can then extend partially within the rotor core also between the radial inner side of the hole and the radial inner side of the rotor core. The divergence of the magnetic lines of force increases the magnetic resistance and reduces the motor efficiency. Leakage flux is particularly prominent in electric pumps, because the distance between the stator and the rotor module is relatively large due to the partition wall, the module housing and the annular gap provided for the secondary flow, which intensifies the leakage flux.

[0008] The invention is based in particular on the recognition that the avoidance or reduction of these magnetic leakages increases the efficiency or effectiveness of the pump. It has been found that the slots on the radial inner side of the rotor core reduce the magnetic leakage between the bore and the radial inner side of the rotor core. As a result, the magnetic field lines are more strongly concentrated on the radial outer region of the rotor core, which increases the efficiency or effectiveness of the pump. As a result, the object mentioned at the beginning is thus achieved.

[0009] Preferably, the rotation axis A defines an axial, radial and / or tangential direction or a circumferential direction. The expression "radially inward" denotes a radial direction toward the rotation axis A. The concept "axially inward" denotes an axial direction corresponding to the direction of the fluid flowing in the inlet. In particular, "axially inward" denotes an axial direction from the impeller toward the rotor module. The axially outermost section of the pump is preferably also 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. In a top view, the tangential direction can extend either in a clockwise direction or in a counterclockwise direction. The rotor preferably rotates in a clockwise direction.

[0010] The magnets are preferably permanent magnets. The rotor or rotor module preferably includes at least six or eight magnets in a cross section. Advantageously, the rotor or rotor module includes at most 20 or 16 or 14 magnets in a cross section. Advantageously, the rotor core is at least partially arc-shaped along its circumference. Preferably, the rotor core has a plurality of magnet positions on its radial outer side for arranging each magnet at each magnet position. It is very preferred that, when viewed in a top view or in a cross section, the magnets are arc-shaped on their radial inner side and / or on their radial outer side. Advantageously, each magnet position has an arc-shaped contour in a top view or in a cross section, and in particular has a face complementary to the magnet.

[0011] It is very preferred that the rotor core has a plurality of overlapping stacked sheets, in particular rotor laminations. The rotor laminations are preferably silicon steel sheets. It is very preferred that the rotor core comprises at least 10 or 15 or 20 sheets or rotor laminations. Advantageously, the rotor core has at most 50 or 40 or 30 rotor laminations. It is suitable that a plurality of sheets or rotor laminations are aligned over the entire circumferential dimension. The sheets or rotor laminations can be connected to each other into a rotor core by means of stamping and packing (Stanzpaketieren) or by means of baking varnish (Backlack). Advantageously, the rotor laminations are provided with an insulating coating.

[0012] According to a particularly preferred embodiment, the pump is designed so that the fluid flushes the module housing of the rotor body during pump operation. This allows the secondary flow to flow from the wheel chamber into the drive chamber. The secondary flow of the fluid can then flow back into the wheel chamber through the rotor in the axial outward direction via a plurality of return channels or a return channel. The secondary flow thus absorbs heat from the stator, rotor and / or printed circuit board, so that the pump can be cooled and can be operated more efficiently overall.

[0013] According to a very particularly preferred embodiment, the rotor body or the module housing has plastic. The rotor body or the module housing is advantageously one-piece and preferably integrally constructed. If the rotor body is integrally and, for example, is made by injection molding or surround injection molding, the rotor body is easily but very stably constructed. Therefore, a lot of details can be realized on the rotor body, which can especially cover the return channel and the blades. As a result, the rotor body can be advantageously manufactured, although it includes quite a lot of technical details. At the same time, the rotor body in the integral construction mode is characterized by a correspondingly large robustness, so that the rotor body can be constructed with relatively thin walls. This also applies to the module housing in a similar manner.

[0014] The rotor preferably comprises a pump wheel and / or a shaft body. The pump wheel advantageously has a wheel disc and / or blades and / or a wheel cover. The wheel disc is preferably arranged axially inwardly relative to the blades. The blades preferably form blade channels between each other in a top view. It is possible that the blades are covered by a wheel cover in the axially outward direction. The wheel cover can be fixed to the blade in particular by means of plugging or welding.

[0015] It is very preferred that the rotor body comprises the blades and / or the wheel disc and / or the shaft body. The shaft body advantageously has a drive section and / or a connecting section. It is suitable that the drive section and the module housing overlap in the axial direction. According to a particularly preferred embodiment, the module housing, the drive section, the connecting section, the wheel disc and / or the blades are connected to each other in one piece and preferably form the rotor body.

[0016] According to a preferred embodiment, the grooves and protrusions alternate in the tangential direction. It is possible that the tangential extension of the grooves is equal to the tangential extension of the protrusions. Preferably, the inner wall of the rotor core is composed only of the grooves and protrusions. This achieves that the largest possible area of ​​the radial inner wall helps to guide the magnetic lines of force. The grooves and 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 module. Advantageously, the upper cover sheet body, the lower cover sheet body, the bracket sheet body and / or the module sheet body have the grooves and protrusions. This achieves that the largest possible area of ​​the radial inner wall helps to guide the magnetic lines of force.

[0017] It is very particularly preferred that the holes are offset relative to the grooves in the tangential direction. Preferably, the holes and the grooves alternate with each other in the tangential direction. It is very particularly preferred that the holes and the grooves do not overlap in the tangential direction.

[0018] Advantageously, there are free spaces between the magnets in the cross section of the rotor module in the tangential direction. Preferably, at least one of these free spaces is provided with a slot in the tangential direction. Advantageously, at least one of these free spaces overlaps with the provided slot in the tangential direction. It is particularly preferred that the at least one free space and its provided slot are designed symmetrically about a common radial line axis. This allows the magnetic lines of force to be guided radially inward or spatially limited, so that the magnetic field remains compact and the magnetic resistance remains small.

[0019] 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, the number of slots and / or the number of protrusions. This allows a targeted influencing of the magnetic field lines for each magnet. If each magnet is provided with a hole, each magnet can be supported in the same way by the hole in the guidance of the magnetic field lines. As a result, practically the same drive of the rotor is achieved by each magnet, so that the greatest possible running quietness is achieved.

[0020] Preferably, in the cross section of the rotor core, in particular in the tangential direction, at least one of the magnets of the rotor module, preferably each of these magnets, is provided with a hole among the holes and / or a protrusion among the protrusions. Advantageously, the at least one magnet overlaps with the associated hole and / or the associated protrusion in the tangential direction. Preferably, the at least one magnet and / or the hole assigned to the magnet and / or the protrusion assigned to the magnet are configured axially symmetrically with respect to a common radius line. Axisymmetry ensures that the magnetic field is always configured as similarly as possible when passing through the rotor module or the rotor core, so that a high degree of running quietness can be achieved.

[0021] Advantageously, at least one of the holes overlaps with the protrusion assigned to the at least one hole in the tangential direction. Preferably, all holes overlap with the correspondingly assigned protrusions in the tangential direction. Preferably, the at least one hole and the protrusion assigned to the hole are symmetrically configured about a common radial line axis. Preferably, the tangential extension of the protrusion is at least 50% or 60% or 70% or 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 is at least 50% or 60% or 70% or 80% or 90% of the cross-sectional area of ​​the assigned hole. This achieves a relatively uniform distribution of the rotor core material over the entire circumference, thereby reducing electromagnetic or mechanical inhomogeneities and improving running quietness.

[0022] Ideally, two of the magnets and preferably all of the magnets of the rotor module have the same shape and / or the same magnetic properties and / or the same radial position in the cross section of the rotor core. Advantageously, two of the holes and preferably all of the holes of the rotor core have the same shape and / or the same radial position. Preferably, two of the protrusions and 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 of the slots and preferably all of the slots of the inner wall of the rotor core have the same shape and / or the same radial position. This allows a uniform or repeated construction of the rotor module in the tangential direction, thus achieving great running quietness.

[0023] Preferably, the radial extent RL of the hole and the radial extent PKV of the rotor core at the circumferential position of the protrusion have a ratio RL / RKV of at most 0.80 or 0.70 or 0.60 or 0.55 or 0.50. This makes it possible for the hole to be relatively flat in proportion to the radial extent of the rotor core. As a result, slightly more space can be left for the magnetic lines of force in the radial outer region of the rotor core, so that the magnetic lines of force can be well confined in the radial outer region. Preferably, the outer diameter AR of the rotor core and the radial extent RKN of the rotor core at the circumferential position of the slot have a ratio AR / RKN of at least 2.0 or 2.3 or 2.5 or 2.7 or 3.0 or 3.2. As a result, the rotor core remains relatively thin or slender in the radial direction in proportion to the outer diameter AR or diameter of the rotor core. In this case, in particular, the ratio AR / RKN can be larger the smaller the ratio RL / RKV.

[0024] According to a preferred embodiment, at least one of the grooves and / or at least one of the protrusions has a polygonal and preferably quadrilateral shape. Advantageously, all the grooves and / or all the protrusions have a polygonal and preferably quadrilateral shape. The relatively uniform shape in the tangential direction makes the radial effect of the grooves or protrusions in the tangential direction uniform. Preferably, the tangential extension dimension of the at least one groove is at least 1.5 times, 2.0 times or 2.5 times the radial extension dimension of the groove. Preferably, the tangential extension dimension of the at least one protrusion is at least 1.5 times, 2.0 times or 2.5 times the radial extension dimension of the protrusion. Therefore, the groove or protrusion is elongated in the tangential direction. This allows the effect of the radial effect of the protrusion or groove to be fully influenced in the tangential direction.

[0025] According to a particularly preferred embodiment, at least one of the holes and preferably all the holes of the rotor core have a polygonal and in particular pentagonal shape in the cross section of the rotor core. Advantageously, the at least one hole has a tip, which is preferably directed radially outward. The tip is used in particular for clean separation of the magnetic field and thus avoiding magnetic leakage. Advantageously, the at least one hole includes a radial outer side. Advantageously, the tip of the hole forms the radially outermost point of the radial outer side of the hole. Preferably, the at least one hole includes two tangential outer sides. Advantageously, the at least one hole includes a radial inner side. The radial inner side of the hole suitably connects the two tangential outer sides of the hole.

[0026] According to a particularly preferred embodiment, at least one of the holes and preferably all the holes of the rotor core are filled with air. It is very particularly preferred that the rotor core has an upper and / or a lower cover body. The upper and / or lower cover body preferably has no holes. The upper and / or lower cover body is advantageously designed so that no plastic flows into the holes of the rotor core during the surrounding injection molding process. This achieves better guidance of the magnetic lines of force. The holes advantageously extend over at least 50% or 60% or 70% or 80% or 90% of the axial extension of the rotor core or rotor module.

[0027] Advantageously, at least one of the grooves has a radial extent RN, the ratio RN / RKN preferably being at least 0.1 or 0.14 or 0.17. This ensures that the magnetic field lines are sufficiently strongly delimited. The ratio RN / RKN is advantageously at most 0.60 or 0.50 or 0.40 or 0.30 or 0.25. This ensures that the magnetic field lines are not too strongly delimited or deformed, so that the magnetic resistance does not increase. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is explained in more detail below with the aid of an embodiment and four drawings. The schematic drawings are as follows:

[0029] Figure 1 shows a longitudinal section view of a pump according to the present invention; and

[0030] Figure 2 show Figure 1 A perspective view of a rotor module of a simplified depiction of a pump;

[0031] Figure 3 show Figure 1 and Figure 2 A cross-sectional view of a rotor module of a simplified description; and

[0032] Figure 4 show Figure 3 Partial view of a rotor module of FIG. 1 , but additionally including a stator of simplified description. DETAILED DESCRIPTION

[0033] The pump according to the invention advantageously comprises an inlet 8 and an outlet 9, which is depicted in dashed lines due to the selected longitudinal section. The pump comprises a rotor 2, which advantageously comprises a pump wheel 6. The pump has a stator 1, which drives a rotor module 4. The rotor module 4 is a component of the rotor 2. The rotor 2 advantageously comprises a shaft body 7, which transmits the torque of the rotor module 4 to the pump wheel 6. The pump wheel 6 preferably comprises blades 19 and / or a wheel disk 31.

[0034] The blades 19 throw the fluid flowing through the inlet 8 radially outward, and the fluid is suitably collected by the collection channel 28 along almost the entire circumference. The collection channel 28 is suitably connected to the outlet 9. In this embodiment, the fluid flow from the inlet 8 via the pump wheel 9 to the collection channel 28 to the outlet 9 is the mainstream of the fluid. Here, the chain of elements 8, 6, 28, and 9 forms a mainstream path.

[0035] Preferably, the pump comprises a partition wall 16 and a housing 15. Very preferably, the partition wall 16 divides the space within the housing 15 into a wet zone and a dry zone. Preferably, the stator 1 is arranged in the dry zone. Advantageously, the pump comprises a circuit board 18 for controlling the operation of the pump and in particular for controlling the stator 1. Preferably, the circuit board 18 is in the dry zone of the pump.

[0036] The wet region of the pump preferably comprises the inlet 8 and the outlet 9. Preferably, the wet region has a wheel chamber 10, within which the pump wheel 6 is arranged. Expediently, the drive chamber 11 adjoins the wheel chamber 10 in the axially inward direction or downward in the longitudinal section, which drive chamber is advantageously formed by a partition wall 16. Very preferably, the rotor module 4 is arranged within the drive chamber 11.

[0037] Preferably, there is a circumferential gap between the partition wall 16 and the impeller 31 or the pump wheel 6, 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 channel 12 and preferably a plurality of return channels 12, which extend approximately in the axial direction within the rotor 2 and connect the lowermost region of the drive chamber 11 to the wheel chamber 10.

[0038] Due to the pressure difference between the radial inside and the radial outside generated by the pump wheel 6, a small part of the fluid, the secondary flow, flows from the wheel chamber 10 into the drive chamber 11 and flows from there beside the rotor module 4 until entering the lowermost area of ​​the drive chamber 11. The secondary flow then enters the lower inlet of a return channel 12 or a plurality of return channels 12, flows through the rotor 2, and finally exits at the top in the radially inner area of ​​the wheel chamber 10. There, the secondary flow mixes with the main flow.

[0039] The secondary flow has the following advantages: the heat of the stator 1, the rotor module 4 and the circuit board 18 is dissipated, so that the pump can work more efficiently as a whole. However, this also means that the rotor module 4 is arranged in the wet area, and corresponding technical requirements for the rotor module 4 or the rotor 2 need to be put forward.

[0040] The rotor 2 of this embodiment includes a rotor body 3, which preferably has plastic. The rotor body 3 can have blades 19, a wheel disc 31, a shaft body 7, a return channel 12 and / or a module housing 17. In this embodiment, the rotor body 3 is made in the injection molding of the rotor module 4 or in the surrounding injection molding. The module housing 17 of this embodiment surrounds the rotor module 4 with the magnet 13 and the rotor core 22. Therefore, very good protection of the rotor module 4 against secondary flow is guaranteed. At the same time, it is possible to produce a very smooth outer surface of the rotor 2 or the rotor body 3 by surrounding injection molding, so that the rotor 2 rotating in the fluid has good fluid dynamic characteristics.

[0041] In this embodiment, the shaft 23 is supported in a rotationally fixed manner in the bottom of the partition wall 16. The shaft 23 defines an axis of rotation A, about which the rotor 2 rotates. The rotor 2 can advantageously have a rotary bearing 5, which can be tribologically optimized and can in particular have graphite. The pump preferably comprises a shaft support 24, which in this embodiment is pressed into the receiving portion of the rotor support. Therefore, an upper axial end side of the rotary bearing 5 rotates relative to a lower axial end side of the shaft support 24. It is very preferred that the rotor body 3 is produced by surrounding injection molding of the rotary bearing 5 and the rotor module 4. The rotor 2 can have a rotor cover 25, which is preferably plugged onto the blades 19. A rotor cover can be provided at the lower end of the motor 2, which is preferably fixed to the rotor 2 only after surrounding injection molding.

[0042] In this embodiment, the module housing 17 is integrally connected to the shaft 7 of the rotor 2 or the rotor body 3 and preferably integrally connected to the impeller disk 31 and / or the blades 19 of the pump wheel. This integral connection is preferably achieved by surrounding the rotor module 4 with injection molding.

[0043] exist Figure 2 The rotor module 4 or the rotor core 22 is simplified in the figure, because the grooves (not shown) on the radial inner side of the rotor core 22 are missing. However, these grooves 32 and protrusions 33 are Figure 3 and Figure 4 The groove 32 and the protrusion 33 particularly preferably extend along the entire axial length of the rotor module 4 or the rotor core 22. Advantageously, the upper cover sheet body 27a, the lower cover sheet body 27b, the support sheet body 21 and / or the module sheet body 20 have the groove 32 and the protrusion 33.

[0044] The magnet 13 is preferably disposed on the radially outer side of the rotor core 22. Figure 2 For this purpose, the rotor module 4 comprises a magnet carrier 14 which holds the magnets 13 on the rotor core 22. Due to the holding of the magnets 13 on the rotor core 22, the rotor module 4 as a whole is sufficiently stable for the subsequent overmolding.

[0045] The rotor core 22 of this embodiment includes 25 overlapping and stacked laminae 20, 21, 27. These laminae 20, 21, 27 are preferably silicon steel sheets. The silicon steel sheets are suitably provided with an insulating cover so as to avoid eddy currents, especially in the axial direction. The laminae 20, 21, 27 of this embodiment can be connected to each other by means of stamping and packaging or by means of baking varnish to form a rotor core 22 that is associated with each other. In this embodiment, the rotor core 22 has exactly 22 module laminae 20 composed of silicon steel sheets, which have the same shape.

[0046] The rotor module 4 of this exemplary embodiment comprises a total of 10 magnets 13, which are preferably designed as permanent magnets. Figure 2 , only five magnets 13 are shown. Preferably, each magnet 13 is designed in the shape of a circular arc on its radial inner side and / or on its radial outer side in a top view toward the rotor module. Advantageously, the rotor core 22 has 10 magnet positions 30 on its radial outer side in this embodiment, each magnet position 30 being assigned to a magnet 13. Preferably, the magnet carrier 14 or the magnet positions 30 or the magnets 13 are arranged equidistantly from one another in the tangential direction.

[0047] In this embodiment, the lowermost sheet is configured as a lower cover sheet body 27b. The lower cover sheet body can have silicon steel sheets or plastic. The lower cover sheet body 27b preferably includes a plurality of, and in this embodiment, ten axial supports 29. It is appropriate that each axial support 29 is assigned to a magnet position 30. The axial supports 29 are preferably configured as axial stops so that the magnets 13 are securely held downward in the axial direction on the rotor core 22. The rotor core can have an upper cover sheet body 27a, which is preferably configured as a module sheet body 20. It is possible that the lower cover sheet body 27b is located above the upper cover sheet body 27a after the pump is assembled, so that the direction of the sheets can be different from the above-mentioned direction of the pump.

[0048] According to a particularly preferred construction, the rotor core 22 includes two support sheets 21 or an upper support sheet 21 and a lower support sheet 21. The two support sheets 21 of this embodiment preferably have a plurality of magnet supports 14, and preferably have a number of magnet supports 14 equal to the number of the magnets. Preferably, the magnet supports 14 are an integral component of the support sheet 21. Preferably, the magnet supports 14 or the support sheet 21 are made by means of stamping. Advantageously, the support sheet 21 is arranged in the upper half of the rotor core 22 or in the upper 1 / 3 or in the upper 1 / 4. It is appropriate that the lower support sheet 21 is arranged in the lower half of the rotor core 22 or in the lower 1 / 3 or in the lower 1 / 4.

[0049] exist Figure 3 , a simplified top view of the rotor module 4 is shown, since the upper cover plate 27 a is omitted in order to reveal the uppermost module plate 20 . Figure 3 and Figure 2 In comparison, there is also the simplification that there are no grooves on the radial outer wall of rotor core 22 . Figure 3 and Figure 2 The illustration is also simplified in that only one magnet carrier 14 is shown.

[0050] According to the invention, the rotor core 22 has grooves 32 and projections 33 on its radial inner wall 34. The grooves 32 are preferably alternated with the projections 33 in the tangential direction. In this embodiment, the tangential extent of the grooves 32 is equal to the tangential extent of the projections 33. Advantageously, the rotor core 22 is designed so that the grooves 32 and the projections 33 complement the inner wall 34 of the rotor core 22. Preferably, the inner wall 34 of the rotor core 22 is formed only by the grooves 32 and the projections 33. It is possible that the tangential extent of one of the grooves 32 is equal to the tangential extent of an adjacent projection 33.

[0051] According to the invention, the rotor core 22 has a plurality of holes 26. Advantageously, the module sheets and / or the carrier sheets have said holes 26. Preferably, the upper cover sheet 27a and / or the lower cover sheet 27b have no holes. The holes 26 are preferably filled with air. This is advantageously achieved by the upper cover sheet 27a and the lower cover sheet 27b having no holes and covering the holes 26 of the other sheets 20, 21. Therefore, the holes 26 are not filled with plastic during the surrounding injection molding process.

[0052] It is very preferred that the hole 26 extends in the axial direction over at least 50% or 60% or 70% or 80% or 90% of the axial extent of the magnet 13. It is advantageous that the groove 32 extends over at least 50% or 60% or 70% or 80% or 90% or 95% of the axial extent of the magnet 13. It is very preferred that the upper cover plate body 27a and / or the lower cover plate body 27b have the groove 32 and the projection 33 on their radial inner side.

[0053] Preferably, the number of magnets 13 is equal to the number of holes 26, the number of slots 32 and / or the number of protrusions 33. Advantageously, in the cross section of the rotor core 22, in particular in the tangential direction, at least one of the magnets 13 and preferably each magnet 13 is provided with one of the holes 26 and / or one of the protrusions 33. Preferably, the at least one magnet 13 overlaps with the associated hole 26 and / or the associated protrusion 33 in the tangential direction. In this embodiment, one hole 26 and one protrusion 33 overlap in the tangential direction. Preferably, the at least one magnet 13 and / or the hole 26 assigned to the magnet 13 and / or the protrusion 33 assigned to the magnet 13 are configured symmetrically about a common radius line.

[0054] Advantageously, the holes 26 are offset from the slots 32 in the tangential direction. Very preferably, the holes 26 and the slots 32 alternate with one another in the tangential direction. Particularly preferably, the holes 26 and the slots 32 do not overlap in the tangential direction. Advantageously, the free spaces between the magnets 13 overlap in the tangential direction with the slots 32 in the tangential direction. Very preferably, one of the free spaces between the magnets is designed symmetrically with respect to a common radial axis with respect to a slot 32 that overlaps with the free space in the tangential direction.

[0055] In this embodiment, at least one hole 26 and preferably all holes 26 are polygonally, preferably at least triangularly and particularly preferably pentagonally formed. The at least one hole 26 preferably comprises a tip 26a, which is advantageously directed radially outward. It is very preferred that the at least one hole 26 comprises a radial outer side 26b. Preferably, the tip 26a forms the radially outermost point of the radial outer side 26b. In this embodiment, the radial outer side 26b is formed by two straight lines facing each other, which advantageously extend in the tangential direction and in the radial direction, respectively. Preferably, the at least one hole 26 comprises two tangential outer sides 26c. Advantageously, the at least one hole 26 comprises a radial inner side 26d. The radial inner side 26d suitably connects the two tangential outer sides 26c.

[0056] The at least one hole 26 and preferably all holes 26 are preferably designed to be relatively flat. Preferably, the tangential extent TL of the at least one hole 26 is greater than the radial extent RL of the hole 26. The rotor core 22 (K) has a radial (R) extent RKV in the region of the projection 33 (V). Very preferably, the ratio RL / RKV is at most 0.70 or 0.65 or 0.50. In this exemplary embodiment, the ratio RL / RKV can be approximately 0.40.

[0057] The rotor core is advantageously designed to be very slender in the radial direction, in particular in the region of the slots 32. The rotor core 22 (K) has a radial (R) extension RKN in the region of the slots 32 (N). The rotor core 22 has an outer radius AR. Preferably, the outer radius AR is the arithmetic mean of all outer radii over a complete cycle. Very preferably, the ratio AR / RKN is at least 2.3 or 2.7 or 3.0. In this embodiment, the ratio can be 3.5. The slots 32 (N) have a radial (R) extension RN. The ratio RN / RKN is preferably at least 0.1 or 0.14 or 0.17 and in the embodiment is approximately 0.21.

[0058] exist Figure 4 Description Figure 3 A partial view of a rotor module 4, wherein the rotor module 4 and Figure 3 In comparison, it is additionally surrounded by a stator 1 which is described in a simplified manner. Figure 4 In particular, the stator windings and the partition walls 16 are omitted. Therefore, the stator 1 described here corresponds essentially to a cross section of a stator core or a top view of a sheet of a stator core. Figure 4 The magnet support 14 and the slots on the radially outer side of the rotor core 22 are also omitted.

[0059] The stator 1 or stator core has a stator ring 35 and a plurality of inwardly projecting poles 36. Each pole 36 expediently comprises a pole core 37 and a pole shoe 38. The stator winding (not shown) is wound around the pole core 37, in particular in the tangential direction, and is held in the radial direction by the pole shoes 38 and by the stator ring 35.

[0060] While the pump is running, press Figure 4 Magnetic lines of force 39a, 39b are formed. The magnetic lines of force 39a, 39b form a closed loop passing 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 the present case, line 39a describes the external magnetic lines of force, while line 39b describes the internal magnetic lines of force.

[0061] exist Figure 4 As can be seen, the holes 26, which are preferably filled with air, influence the extent of the magnetic field lines 39a, 39b and in particular the extent of the outer magnetic field lines 39a, so that the outer magnetic field lines 39a extend along the radial outer side 26b of the hole 26 and along the tangential outer side 26c of the hole 26. The outer magnetic field lines 39a are also delimited radially inwardly, in particular, by the grooves 32.

[0062] Therefore, the magnetic flux lines 39a, 39b are concentrated on the smallest possible outer area within the rotor module 4 or the rotor core 22, thus achieving a correspondingly small magnetic resistance. In particular, the magnetic flux lines are concentrated on the radial outer area of ​​the rotor core 22 by means of the holes 26 and the slots 32, and magnetic leakage is also avoided. This is particularly advantageous for pumps with partition walls and secondary flows, because the distance between the stator 1 and the rotor module 4 is greater here and the tendency of the magnetic field to diverge and the tendency of magnetic leakage are therefore also greater. Reference numerals list

[0063] ARotation axis

[0064] 1 Stator

[0065] 2 rotors

[0066] 3 Rotor body

[0067] 4 rotor modules

[0068] 5. Rotary bearing

[0069] 6 Pump wheel

[0070] 7-axis

[0071] 8Entrance

[0072] 9Exit

[0073] 10 round room

[0074] 11Drive room

[0075] 12Return channel

[0076] 13 Magnets

[0077] 14 Magnet Bracket

[0078] 15 Shell

[0079] 16 Partition wall

[0080] 17 Module housing of rotor, rotor body

[0081] 18 Circuit Board

[0082] 19 Pump impeller blades

[0083] 20 module body

[0084] 21 bracket sheet

[0085] 22 rotor core

[0086] 23 Axis

[0087] 24 axis bracket

[0088] 25 rotor wheel cover

[0089] 26 holes

[0090] 27a The cover body above

[0091] 27b Cover sheet body below

[0092] 28 Collection Channels

[0093] 29 Axial bracket

[0094] 30 magnet positions

[0095] 31 Roulette

[0096] 32 slots

[0097] 33 protrusions

[0098] 34 Inner wall

[0099] 35 stator ring

[0100] 36 poles

[0101] 37 pole core

[0102] 38 pole shoes

[0103] 39a Magnetic field lines outside

[0104] Magnetic field lines inside 39b

[0105] AR Outer Radius

[0106] Radial extension of RN groove

[0107] Radial extension of RL hole

[0108] The radial extension of the RKN rotor core at the slot

[0109] The radial extension of the RKV rotor core at the protruding part

[0110] Tangential extension of TL hole

Claims

1. A pump for driving a fluid, preferably a temperature control medium, the pump being particularly used in a vehicle, particularly preferably used for temperature control of a power battery of an electric vehicle, the pump comprising a stator (1) and a rotor (2), the rotor (2) comprising a rotor body (3) and a rotor module (4), and the rotor being rotatably supported about a rotation axis (A), the rotor module (4) comprising a metallic rotor core (22) and a plurality of magnets (13), the rotor core (22) comprising a plurality of holes (26) in a cross section, characterized in that The rotor core (22) has a plurality of grooves (32) and a plurality of protrusions (33) on its radial inner wall (34) in cross section.

2. The pump according to claim 1, wherein The pump is designed such that the fluid flushes the module housing (17) of the rotor body (3) during pump operation.

3. The pump according to claim 1 or 2, wherein: The holes (26) are offset relative to the grooves (32) in the tangential direction. Preferably, the holes (26) and the grooves (32) alternate with each other in the tangential direction.

4. A pump according to any one of claims 1 to 3, 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 number of the slots (32) and / or the number of the protrusions (33).

5. The pump according to any one of claims 1 to 4, wherein: At least one of the holes (26) and a projection (33) assigned to the at least one hole (26) in a tangential direction overlap in a tangential direction.

6. A pump according to any one of claims 1 to 5, wherein: The radial extent RL of the hole (26) and the radial extent PKV of the rotor core (22) at the circumferential position of the projection (33) have a ratio RL / PKV of at most 0.70 or 0.65 or 0.

50.

7. A pump according to any one of claims 1 to 6, wherein: At least one of the grooves (32) and / or at least one of the projections (33) has a polygonal and preferably quadrilateral shape.

8. A pump according to any one of claims 1 to 7, wherein: At least one of the holes (26) has a polygonal, preferably pentagonal, shape.

9. A pump according to any one of claims 1 to 8, wherein: At least one of the holes (26) is filled with air.

10. A pump according to any one of claims 1 to 9, wherein At least one of the grooves (32) and preferably all of the grooves (32) have a radial extent RN, with a ratio RN / RKN of at least 0.1 or 0.14 or 0.17.

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