Pump for driving fluid

Abstract

The invention relates to a pump for driving a fluid, comprising a stator (1) and a rotor (2), the rotor (2) comprising a rotor body (3), a rotor module (4) and a rotary bearing (5), the rotor (2) being rotatably mounted about an axis of rotation (A), the rotor (2) or rotor body (3) having a pump wheel (6) and a shaft body (7), the rotor (2) or rotor body (3) comprising a module housing (44), the invention relates to a pump comprising a module housing at least partially surrounding a rotor module (4), at least one section of an inlet (8) of the pump being provided in an axial upper half of the pump, the pump comprising an outlet (9).

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, a rotor module and a rotary bearing, the rotor being rotatably supported around an axis of rotation, the rotor or the rotor body comprising a pump wheel and a shaft, the rotor or the rotor body having a module housing, the module housing at least partially surrounding the rotor module, at least one section of an inlet of the pump being arranged in an axially upper half of the pump, the pump comprising an outlet. Background Art

[0002] EP3318765A1 discloses an electrically driven coolant pump, which includes an external stator and an internal rotor. The rotor includes a rotor body, upper and lower rotary bearings, and a rotor module with a magnet. The rotor module is partially surrounded by a module housing. The rotor body has a pump wheel and a shaft body. The shaft body includes a connecting section and a module housing, which connects the module housing and the pump wheel in the axial direction. The rotor body is configured as an injection molded component and is therefore integrally configured, and the module housing surrounds the magnet in the axial direction. The two bearings are configured as sliding rotary bearings and allow the rotor to rotate around an axis with low friction. The upper bearing is additionally configured as a tilting bearing to minimize the friction between the upper shaft support and the upper sliding bearing. During operation, the stator, rotor, and control electronics of the pump generate heat and need to be cooled. This cooling is guaranteed by a secondary flow path, which includes a return channel adjacent to the rotor module within the rotor. The return channel is exactly arranged at the following position, at which the lower rotary bearing protrudes less radially. The space in the rotor body or in the shaft body is thus utilized optimally.

[0003] A coolant pump is described in DE102018125031A1, which also has a secondary flow path. For this purpose, the rotor has a plurality of return channels, which cool the rotor module from the radial inner side of the rotor module. Therefore, the rotor module is cooled more, and the imbalance of the rotor is reduced and the wear is reduced by the plurality of return channels at the same time. The rotor module is fixed on the central rotor shaft so that the rotor shaft is rotatably supported in the intermediate wall. The rotor shaft passes through the intermediate wall and drives the pump wheel. For this purpose, the intermediate wall includes a fixedly mounted rotary bearing in which the rotor shaft can rotate. The rotary bearing does not overlap with the return channel in the rotor body in the axial direction because the structural space is scarce. Instead, the rotary bearing has an axially extending groove on its inner side, which follows the return channel of the rotor in the flow direction of the secondary flow. These fixed grooves connect the rotating return channel of the rotor body to the wheel chamber, in which the secondary flow mixes with the mainstream.

[0004] Known coolant pumps are designed to cool the internal combustion engine, and only when the internal combustion engine has been hot-running for a period of time, these coolant pumps are fully loaded. Here, known coolant pumps are especially supported by the travel wind. Summary of the invention

[0005] The invention is now based on the object of designing a pump for thermal management of an electric vehicle (“thermostatic pump”) and thus designing the pump to be more powerful and at the same time more cost-effective.

[0006] Energy transformation and mobility transformation require the establishment of new technologies, which especially cover electric vehicles with power batteries and electric motors. The power battery reaches its maximum efficiency at a temperature of about 20°C, so that the power battery needs to be heated or cooled according to different operating conditions. Heating is especially suitable shortly after starting in winter, while cooling is especially considered when the vehicle has been driving for a period of time. That's all, the thermal management of the drive train in electric vehicles is different 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.) is designed to work in addition in cold seasons and therefore without driving wind support. This means that, looking at the whole year, a relatively large throughput of the temperature control fluid of the electric vehicle is required. Therefore, the coolant pump or temperature control pump needs to be constructed with corresponding working capacity.

[0007] The object is achieved by a pump for driving a fluid, in particular a temperature control medium, the pump being used in particular in a vehicle, particularly preferably 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, a rotor module and a rotary bearing, the rotor being rotatably supported about an axis of rotation, the rotor or the rotor body comprising a module housing which at least partially surrounds the rotor module, at least one section of the inlet of the pump being arranged in the axial upper half of the pump, the pump comprising an outlet. This allows the pump to be designed in such a way that the object mentioned at the outset is achieved.

[0008] Preferably, the pump comprises a housing and a partition wall, which divides the space within the housing into a wet area and a dry area. The wet area advantageously has a wheel chamber and a drive chamber, the pump wheel being located in the wheel chamber. Preferably, the module housing is arranged in the drive chamber. Possibly, the pump has a circuit board for controlling the operation of the pump. It is expedient that the stator and / or the circuit board are located in the dry area. This allows protection of the electrical / electronic components and at the same time allows flushing of the rotor.

[0009] Preferably, the pump wheel is conveniently arranged between the inlet and the outlet in the flow direction of the main flow path of the fluid. Advantageously, the pump is configured so that a secondary flow path of the fluid branches off from the main flow path and extends from the wheel chamber into the drive chamber. This allows cooling of the stator, the rotor or the rotor module and / or the circuit board.

[0010] According to a very preferred embodiment, the rotor or rotor body has at least one return channel for the secondary flow and preferably has a plurality of return channels, which establish a fluid connection between the drive chamber and the wheel chamber. It is appropriate that the return channels are separated from each other by a partition element of the rotor or a partition element of the rotor body. The present invention is based on the following recognition: A particularly critical aspect of working capacity is as little wear as possible. Less wear is decisive for reducing the probability of maintenance of the pump during the life of the electric vehicle. It has been found that wear occurs especially on the rotary bearings of the rotor. This wear is especially related to the imbalance that occurs in the rotor in addition to the total service life (the average number of revolutions until the end of the life of the pump). The present invention is based on the following recognition: multiple return channels are arranged within the rotor, which significantly reduces the imbalance of the rotor, and thus ultimately also reduces wear, increases the total service life and improves the working capacity of the pump.

[0011] It is particularly preferred that the pump comprises a non-rotatable shaft on which the rotor is rotatably mounted. This allows particularly low wear on the rotary bearing and promotes a long service life. The shaft preferably comprises metal, more preferably steel, and in particular high-quality steel.

[0012] The invention is based on the following knowledge: a solid shaft body without an axial through hole for a shaft can only be supported partially in the axial direction on an external rotary bearing. Since the other axial sections of the solid shaft body have to take on other tasks and are in particular assigned to a rotor module or a pump wheel, the axial length of the external rotary bearing of the solid shaft body is therefore relatively short compared to the total length of the shaft body.

[0013] In the case of a shaft, on the other hand, the rotor modules and the rotary bearing or inner rotary bearing can overlap over a longer section in the axial direction, so that a relatively large rotary bearing length can be achieved in the system with the shaft. As a result, the rotor runs more quietly in the shaft system overall, which leads to less wear, a longer service life and, as a result, a more powerful pump. As a result, the object mentioned at the beginning is thus achieved.

[0014] The axis of rotation A defines axial, radial and tangential directions or circumferential directions. The circumferential directions preferably refer to a top view and therefore to a perspective from the outside into the inlet. The direction of rotation of the rotor expediently extends in the circumferential direction in a clockwise direction. The expression "axially inwards" preferably relates to the flow direction of the fluid in the inlet. The flow direction of the fluid in the inlet, shortly before the pump wheel or the rotor support, preferably points from top to bottom. Therefore, the expression "axially inwards" corresponds to the expression "from top to bottom".

[0015] The rotor module preferably comprises a rotor core. Preferably, the rotor module has a plurality of magnets, and in particular a plurality of permanent magnets. It is suitable that the rotor module or the rotor core is substantially annular in cross section. Preferably, the magnets are fixed to the radially outer side of the rotor core. It is very preferred that the rotor core has a plurality of rotor laminations stacked one on top of the other. The rotor laminations are preferably silicon steel sheets. The rotor laminations can be connected to each other into a rotor core by means of stamping and packaging (Stanzpaketieren) or by means of baking varnish (Backlack). Advantageously, the rotor laminations are provided with an insulating coating.

[0016] The rotor module and the module housing suitably form a drive section of the rotor in the axial direction. Preferably, the rotor includes a connecting section between the drive section and the pump wheel in the axial direction. Suitably, the drive section and the connecting section of the rotor or the rotor body form a shaft body. Preferably, the module housing or the drive section divides the drive chamber into an upper cavity above the module housing and advantageously into a lower cavity below the module housing.

[0017] It is possible that the rotary bearing is subjected to a rotary sliding movement with its radial inner side or with its radial outer side. The rotary bearing can consist of the same material as the rotor body and can in particular be an integral component of the rotor body. The rotary bearing can consist of a different material than the rotor body.

[0018] Preferably, the housing comprises an upper housing part and a lower housing part. In particular, in the axial direction, the circuit board is preferably arranged between the partition wall and the lower housing part. In particular, in the radial direction, the stator is preferably arranged between the partition wall and the lower housing part. In particular, in the axial direction, the rotor is advantageously located between the upper housing part and the partition wall.

[0019] The partition wall preferably comprises a bottom, a side wall, a collar and / or a partition wall flange. The upper housing part preferably has an upper housing flange. The lower housing part advantageously comprises a lower housing flange. The pump advantageously comprises a stator support. The stator and the stator support preferably form a stator assembly. The stator support advantageously has a support flange.

[0020] The inlet is particularly preferably designed coaxially with the rotor. This achieves a small pressure loss on the pump wheel. Preferably, the collecting channel arranged around the pump wheel is provided for collecting the fluid thrown out radially outward. Preferably, the collecting channel has an increasing net cross-sectional area in the clockwise direction. This achieves that a constant pressure is provided along the collecting channel, thereby also generating a relatively constant pressure drop along the collecting channel towards the radial inside. The outlet is preferably designed as a tangential extension of the surrounding channel. Thus, a small pressure loss is achieved.

[0021] According to a particularly preferred embodiment, the rotor has a protrusion for reducing turbulence in the length section of the pump, which protrudes in the radial direction and at least partially and preferably completely covers the inlet of the return channel, preferably the inlet of all return channels, when viewed from the lower side of the rotor. This achieves the shielding of a return channel or multiple return channels and the partition element from the lower cavity, so that these turbulent elements have only a small effect on the amount of fluid in the lower cavity. Therefore, the rotor or the pump as a whole becomes more stable and the current consumption of the pump is reduced. Preferably, the protrusion forces the fluid to deviate from the purely axial flow direction in the region of the inlet of a return channel or the inlet of multiple return channels. Advantageously, the protrusion changes the inlet of a return channel or the inlet of multiple return channels so that the surface normal of the fluid effective area or the net area of ​​the inlet deviates from the purely axial extension direction. It is particularly preferred that the surface normal of the inlet into the return channel extends in a radial or purely radial direction, and in particular in an outward radial direction or a purely radial outward direction.

[0022] It is very preferred that the rotor has a rotor cover, which is fixed to the lower end of the rotor. The rotor cover can be fixed to the rotor or the rotor body, for example, by means of ultrasonic welding. It is particularly preferred that the rotor cover has the protrusions for reducing turbulence. This simplifies the injection molding technology of the rotor body.

[0023] It is very advantageous if the rotor body is designed in one piece and preferably in one piece, in particular by means of injection molding or overmolding. The one-piece structure achieves a relatively high stability, which is significant from the perspective of the service life and the high total number of rotations associated therewith. The one-piece structure of the rotor body in the form of injection molding or overmolding makes it possible to significantly reduce the number of components and the number of connection steps and thus keep the manufacturing effort low.

[0024] The pump wheel preferably comprises a wheel disc and / or blades for guiding a fluid. The blades are preferably connected to the wheel disc in one piece and in particular in one piece. Preferably, the rotor body comprises the wheel disc and / or the blades. The blades suitably form blade channels between each other. The rotor or the rotor body or the pump wheel preferably has five blades or blade channels, and particularly preferably has seven blades or blade channels.

[0025] The rotor advantageously comprises a wheel cover. The wheel cover and the rotor body or the blades are preferably plugged into each other and / or welded to each other. The wheel cover is preferably used to close the pump wheel upwards so that not the blades but only the upper side of the wheel cover can come into contact with the upper housing part. As a result, wear of the blades is practically excluded, thereby extending the service life of the pump.

[0026] It is very particularly preferred that the rotor body or the module housing surrounds the rotor module in the radial direction at least along an axial section and at least along a surrounding section. Preferably, the rotor body or the module housing surrounds the rotor module in the radial direction along the entire axial extension of the rotor module and / or along the entire surrounding dimension of the rotor module. Therefore, the metal components of the rotor module are shielded from the fluid. In addition, the rotor module is surrounded by the rotor body or the module housing so that the outer side of the rotor module is smooth, so that the metal parts of the rotor module do not damage the partition wall. And finally, the enclosure of the rotor module achieves a particularly smooth radial outer side of the drive section of the rotor, thereby reducing the turbulence generated by the drive section to a minimum.

[0027] According to a very preferred embodiment, the circuit board is arranged on the outer side of the partition wall. Preferably, the circuit board includes an electronic control unit, such as a transistor and in particular a MOSFET. Advantageously, the circuit board is arranged on the bottom of the partition wall. Very preferably, the heat-conducting element is between the circuit board and the partition wall. The heat-conducting element advantageously includes a heat-conducting paste. Preferably, the electronic control unit contacts the heat-conducting paste or the heat-conducting element. Thus, a particularly advantageous dissipation of the heat generated on the circuit board is ensured. Preferably, the circuit board has an electrical connection structure for connecting to the stator. Preferably, the electrical connection structure is mechanically supported by a support element. Therefore, the circuit board is mechanically held mechanically not only by the electrical connection structure to the stator, but also by the support element. Preferably, the circuit board includes a second support element. The second support element is arranged in a region of the circuit board with reference to the rotation axis A, which region is opposite to the region of the first support element on the circuit board. The second support element connects the circuit board to the stator or the stator bracket or the stator assembly in a suitable manner.

[0028] Advantageously, the return channel is within the rotor or rotor body. Advantageously, the rotor or rotor body completely surrounds at least one return channel and preferably all return channels in the cross section at least partially in the axial direction. A return channel or multiple return channels are completely surrounded by the rotor body accordingly, so that the boundary surface within the rotor (for example, between the rotor body and the rotor module or between the rotor body and the rotary bearing) is particularly uniformly constructed. Therefore, fewer edges are produced, so that the rotor obtains stability and becomes more wear-resistant. This is applicable to a very special extent for the following boundary surfaces: the boundary surfaces slide over each other during the operation of the pump. But this also applies to the following boundary surfaces within the rotor: the boundary surfaces do not slide over each other. If there are grooves there, these grooves usually lead to edges, or generally lead to undesirable artifacts, so that, for example, the flow characteristics of the fluid in the return channel can be damaged.

[0029] According to a particularly preferred embodiment, the rotary bearing has an effective axial rotary bearing length DL and the shaft has an effective shaft length AL. Preferably, the ratio DL / AL is greater than or equal to 0.40 or 0.45 or 0.50 or 0.55 or 0.60 or 0.65 or 0.70. The term "effective axial rotary bearing length" preferably refers to the axial length of the surface of the rotary bearing that contacts the shaft. The expression "effective shaft length" preferably refers to the axial length of the shaft with which the shaft protrudes from the bottom of the partition wall and which simultaneously provides a contact surface for the rotary bearing or the shaft support. For example, a chamfer on the upper end of the shaft does not contribute to the effective shaft length AL. In particular, the section of the shaft surrounded by the partition wall or the bottom of the partition wall does not contribute to the effective shaft length. The largest possible ratio DL / AL achieves that wear is minimized because the forces acting on the rotary bearing and the shaft are distributed over a very large area or distributed to a very long extended rotary bearing.

[0030] It is very particularly preferred that the pump has a shaft support. Advantageously, the shaft support is arranged in the upper half of the shaft, or in the upper 1 / 3 of the shaft, or in the upper 1 / 4 of the shaft. The shaft support preferably comprises metal, further preferably steel, and in particular high-quality steel. It is very preferred that the shaft support at least partially and preferably completely surrounds the shaft in the circumferential direction. Preferably, at least in the partially disassembled state of the pump, the shaft can slide in the shaft support in the axial direction, and advantageously at the same time no radial play is available in the shaft support.

[0031] The shaft support has an effective axial support length HL. The term "effective axial support length" preferably refers to the axial length of the shaft support along which the shaft support is in contact with the shaft. In particular, chamfers on the radial inner side of the shaft support do not contribute to the effective axial support length HL. Very particularly preferably, the ratio HL / AL is at least 0.07 or 0.10 or 0.13 or 0.15 or 0.17. This allows a particularly stable holding of the shaft at its upper end, thus achieving greater running quietness and less wear.

[0032] The ratio (DL+HL) / AL is very advantageously at least 0.5 or 0.6 or 0.7 or 0.8 or 0.9. This ensures that as little effective shaft length as possible remains unused. The invention is based on the understanding that the effective shaft length AL provided by the shaft can be used as much as possible and should be used in particular for a rotary bearing that is as extended as possible in the axial direction and for a shaft support that is as extended as possible in the axial direction. The ratio DL / HL is advantageously 1 to 10, preferably 2 to 7, further preferably 2.5 to 5, and very particularly preferably 3 to 4.

[0033] Advantageously, the rotor has a slight axial clearance on the shaft available in the stationary state of the pump or in the state without fluid. It is possible that the rotor does not rest on the shaft support in the state with stationary fluid or in the state without fluid. It is very preferred that the pump is configured so that during pump operation, the rotor or rotor body or rotary bearing rests on the lower axial end face of the shaft support with an upper axial end face. It is suitable that the upper axial end face of the rotary bearing and the lower axial end face of the shaft support are subjected to sliding friction with each other. It is very preferred that the upper axial end face of the rotary bearing is the same as the surface extension size of the lower axial end face of the shaft support in terms of its surface extension size. Depending on the different conditions of the speed and therefore the different conditions of the pressure generated, the axial clearance allows secondary flows with different strong effects. At high pressures in the collecting channel, a relatively large pressure is also generated in the drive chamber by a correspondingly strong secondary flow, which lifts the rotor until it rests on the shaft support at the maximum. Therefore, according to different conditions of the pump power, the cooling of the electrical components is adapted.

[0034] Preferably, the radial extent of the upper axial end face of the rotary bearing is greater than the radial extent of the rotary bearing in the lower region. Preferably, the rotary bearing comprises a flange in the upper half or in the upper 1 / 3 or in the upper 1 / 4. This allows a good form-fitting connection with the rotor body and increases the stability of the rotor.

[0035] It is very preferred that the rotary bearing abuts against the shaft along at least one axial section over the entire circumference or has no grooves. Therefore, the rotary bearing is particularly stable, instead of additionally having to undertake the task of guiding the fluid on its inner side.

[0036] Preferably, the rotary bearing comprises a material different from that of the rotor body or the shaft body or the pump wheel. The rotary bearing advantageously comprises carbon and in particular graphite. The rotary bearing preferably comprises an adhesive and in particular a polymer. Advantageously, the rotary bearing is not integrally connected to the pump wheel or is not an integral component of the rotor body. This achieves that, on the one hand, the rotor is provided with good sliding properties by means of a rotary bearing having a material optimized for sliding friction. At the same time, the material of the rotor body is optimized for force transmission and in particular for the transmission of torsional forces, so that different materials are considered for the rotor body or the shaft body than for the rotary bearing. The rotor body advantageously comprises a thermoplastic, preferably an engineering thermoplastic, further preferably a high-performance thermoplastic, and for example polyphenylene sulfide (PPS).

[0037] Advantageously, a rotor support is arranged between the inlet and the impeller in the flow direction. The rotor support is preferably fixed to the housing or an upper housing part. The rotor support preferably has at least two legs and further preferably at least three legs. It is very particularly preferred that the rotor support comprises exactly three legs. The legs of the rotor support are preferably arranged or fixed on the inner side of the inlet. Advantageously, the rotor support is connected to the inlet or to the upper housing part or to the housing in a single piece and preferably in one piece. The rotor support expediently comprises a receiving portion for mounting a shaft support on its underside. Preferably, the shaft support is pressed into the receiving portion of the rotor support. The rotor support realizes and therefore allows a relatively low-turbulence fixing of the shaft support on the housing.

[0038] According to a preferred embodiment, an annular gap extends between the radially outer side of the drive section or the module housing and the inner side of the partition wall or the inner side of the side wall of the partition wall. The secondary flow path advantageously has this annular gap. Preferably, the annular gap fluidically connects the cavity above the drive chamber with the cavity below the drive chamber. This allows the fluid to cool the inner side of the stator and the outer side of the rotor module.

[0039] Preferably, the pump wheel or wheel disc and the collecting channel or the partition wall or the collar of the partition wall form a surrounding gap, which connects the collecting channel or the wheel chamber to the drive chamber or the cavity above the drive chamber. The surrounding gap allows a significant amount of liquid to pass through based on the almost complete surrounding size, so that the stator, rotor module and circuit board are fully cooled. At the same time, the surrounding gap allows turbulence to be avoided. If, for example, there are multiple defined channels from the collecting channel to the cavity above, the corresponding inlets and outlets respectively generate turbulence. Therefore, the surrounding gap is generally slightly more advantageous in terms of fluid dynamics than multiple single channels.

[0040] According to a particularly preferred embodiment, the partition wall preferably has ribs on its inner side in the lower region of the drive chamber. It is expedient to provide a plurality of ribs on the inner side of the bottom of the partition wall. This achieves reinforcement of the bottom or the partition wall and thus improves the shaft stability. This in turn is conducive to the quietness of the pump and reduces wear. In addition, the ribs are advantageous relative to the solid construction of the bottom, because thick-walled areas can easily lead to defects during injection molding. These defects include shrinkage cavities and material shrinkage in particular. The ribs preferably extend in the radial direction with their longitudinal extension.

[0041] Advantageously, the partition wall or the bottom of the partition wall has an axle fixing on its inner side. The axle fixing is advantageously arranged in the center of the bottom or the center of the partition wall in a length section. Preferably, the axle fixing is a one-piece and in particular an integral component of the bottom or the partition wall. Very particularly preferably, the axle fixing is produced by means of surrounding injection molding of the axle. Advantageously, the axle comprises an asymmetric region in the axial section surrounding the injection molding of the axle fixing. This serves to prevent the axle from rotating in the axle fixing or in the bottom or in the partition wall.

[0042] According to a preferred embodiment, the partition wall comprises a thermoplastic, preferably an engineering thermoplastic, more preferably a high-performance thermoplastic and particularly preferably polyphenylene sulfide (PPS). Very preferably, the partition wall comprises a thermal conductivity additive for increasing the thermal conductivity. The thermal conductivity additive preferably comprises carbon and more preferably graphite.

[0043] Advantageously, the pump comprises a stator support. Preferably, the stator support has a support flange. Preferably, the support flange abuts against the housing flange, in particular against the upper housing flange and / or the lower housing flange, and particularly preferably against the lower housing flange. This allows very rapid assembly of the pump, because the stator support can be installed in the lower housing part together with the entire stator. Advantageously, the support flange abuts against the partition wall flange. It is suitable that the support flange is arranged between the partition wall flange and the lower housing flange in the axial direction. Preferably, the partition wall flange abuts against the upper housing flange and / or the support flange. Preferably, the partition wall flange is arranged between the upper housing flange and the support flange or the lower housing flange. Preferably, the fixing device, in particular the threaded device, tightens or passes the upper housing flange, the partition wall flange, the support flange and / or the lower housing flange to each other. This allows rapid fixing of all large components of the pump.

[0044] According to a very preferred embodiment, the pump comprises a lower housing part, a stator assembly, a partition wall assembly and an upper housing part, the stator assembly having the stator and preferably a stator support, the partition wall assembly comprising the partition wall and preferably a shaft, and the pump can be assembled in the following order: lower housing part, stator assembly, partition wall assembly, rotor, upper housing part, or in the reverse order. These two orders are possible during assembly, which does not exclude other orders. For example, the rotor can be mounted on the shaft of the partition wall assembly so that the partition wall assembly can then be mounted on the stator assembly together with the rotor.

[0045] Advantageously, the stator assembly has the circuit board. According to a preferred embodiment, the lower housing part has an external electrical connection. Very preferably, the external electrical connection is connectable or connected to the circuit board via a cable. It is suitable that the cable is connected to the lower housing part and the circuit board, and then the stator assembly is installed in the lower housing part or the lower housing part is installed on the stator assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be explained in more detail below with the aid of embodiments and drawings. The drawings are as follows:

[0047] Figure 1 A longitudinal section showing a pump according to the present invention;

[0048] Figure 2 show Figure 1 A perspective view of an enlarged part;

[0049] Figure 3 show Figure 1 A top view of a rotor body of a pump; and

[0050] Figure 4 show Figure 1 Bottom view of the rotor body. DETAILED DESCRIPTION

[0051] exist Figure 1 The pump 42 is preferably used in a vehicle, and is particularly preferably used to control the temperature of a power battery of an electric vehicle. In particular, the pump is a temperature control pump, which drives a temperature control medium through a fluid pipeline to a power battery of an electric vehicle.

[0052] The pump conveniently comprises an inlet 8 and a Figure 1, the outlet 9 is depicted only with a dotted line due to the selected cross section. The pump comprises a pump wheel 6, which works in a clockwise direction. Therefore, the fluid from the inlet 8 is thrown outward and advantageously enters the surrounding collecting channel 28. Preferably, the net cross-section of the collecting channel 28 increases in the clockwise direction to the outlet 9 so as to keep the pressure in the collecting channel 28 approximately constant along the preferably substantially complete surrounding dimension of the collecting channel. The path of the fluid from the inlet 8 to the outlet 9 via the pump wheel 6 and the collecting channel 28 is the mainstream path for the fluid provided by the pump. The pump wheel 6 of this embodiment comprises a total of seven blades 19, which throw the fluid radially outward.

[0053] The pump is electrically driven, for which purpose the pump comprises a stator 1 and a rotor 2. It is expedient that the rotor 2 is arranged within the stator 1. The stator 1 can comprise a stator core 34, which is described in a simplified manner, and a stator winding 35, which is described in a simplified manner. The stator core 34 can be designed in a known manner as a surrounding ring with a plurality of pole shoes. It is possible that the stator core 34 consists of a stack of stator laminations. Preferably, the stator 1 is arranged on or on a stator support 29. It is expedient that the pump comprises a housing 15. In this embodiment, the housing 15 has an upper housing part 15a and a lower housing part 15b.

[0054] The rotor 2 comprises a rotor body 3, a rotor module 4, a rotary bearing 5 and / or a pump wheel 6. The rotor 2 is preferably supported rotatably around an axis of rotation A on a rotationally fixed shaft 23. The shaft 23 preferably comprises metal, more preferably steel, and in particular high-quality steel. Preferably, the shaft 23 tapers at its upper end by chamfering.

[0055] The rotor 2 of this embodiment comprises a wheel cover 25, which closes or covers the pump wheel 6 toward the inlet 8 or upward. The wheel cover 25 can have a central opening. The pump wheel 6 is preferably located in the wheel chamber 10 formed by the housing 15. It is very preferred that the rotor 2 or the rotor body 3 or the pump wheel 6 comprises a plurality of and preferably seven blades 19 and / or a wheel disk 36.

[0056] The rotor module 4 of this embodiment includes a rotor core 33 and preferably a plurality of magnets 32. The magnets 32 may be cuboid or slightly curved and may be advantageously disposed on the radially outer side of the rotor core 33.

[0057] The rotor 2 or the rotor body 3 preferably comprises a module housing 44, which at least partially surrounds the rotor module 4, and in this embodiment completely surrounds it. The rotor body 3 or the module housing 44 advantageously comprises plastic and is preferably produced by injection molding the rotor module 4 and / or the rotary bearing 5.

[0058] The rotor 2 or the rotor body 3 advantageously has a shaft body 7. Preferably, the shaft body 7 comprises a drive section and / or a connection section in the axial direction. Advantageously, the drive section comprises a module housing 44. Preferably, the connection section is arranged between the drive section or the module housing 44 and the pump wheel 6 or the impeller 36 in the axial direction.

[0059] The pump preferably has a partition wall 16. The partition wall 16 preferably comprises plastic, in particular engineering plastic, further preferably high-performance plastic and in particular polyphenylene sulfide (PPS). Advantageously, the partition wall 16 has a thermal conductivity additive for increasing the thermal conductivity. The thermal conductivity additive can in particular comprise carbon, preferably graphite. Advantageously, the partition wall 16 is formed in one piece and in particular in one piece. The partition wall 16 preferably has a bottom 16a, a side wall 16b, a collar 16c and / or a partition wall flange 16d.

[0060] The partition wall 16 or the bottom 16a preferably comprises an axle fixing portion 42. The axle fixing portion is advantageously connected in one piece and in particular in one piece to the bottom 16a or the partition wall 16. Preferably, the axle 23 is fixed in the partition wall or in the bottom 16a, in particular to the axle fixing portion 42. The axle fixing portion 42 is advantageously produced by means of surrounding injection molding around the lower end region of the axle 23. The bottom 16a in this embodiment comprises a plurality of ribs 17, which reinforce the bottom 16a or the axle fixing portion 42.

[0061] The side wall 16b or the partition wall of this embodiment is suitably hollow cylindrical and can limit the drive chamber 11 in the radial direction. The drive chamber is preferably bounded in the axial direction by the bottom 16a or the pump wheel 6 or the wheel disc 36. Preferably, the rotor 2 or the rotor module 4 is present within the drive chamber 11. Advantageously, there is an upper cavity between the module housing 44 and the pump wheel or the wheel disc 36 in the axial direction. It is suitable that there is a lower cavity between the module housing 44 and the bottom 16a in the axial direction. An annular gap 21 is preferably provided between the side wall 16b and the module housing 44 or the drive section of the shaft body 7 or the drive section of the rotor 2.

[0062] The collar 16c can in particular define a part of the wheel chamber 10 and / or a part of the collecting channel 28, preferably together with the upper housing part 15a. The collar 16c is preferably located in the upper half of the partition wall. The partition wall flange 16d is preferably descending downward relative to the collar 16c.

[0063] The partition wall 16 suitably divides the space within the housing 15 into a wet area and a dry area. Advantageously, the wet area corresponds to the internal volume formed by the upper housing part 15a and the partition wall 16. Preferably, the dry area corresponds to the internal volume formed by the partition wall and the lower housing part 15b. Preferably, a fluid seal 20a is provided between the upper housing part 15a and the partition wall 16. In this embodiment, the fluid seal 20a surrounds the partition wall 16 in the radial direction.

[0064] The pump preferably comprises a circuit board 18 for controlling the operation of the pump. The circuit board 18 is advantageously located in the dry area of ​​the pump. Preferably, the circuit board 18 is in contact with a heat-conducting element 38. The heat-conducting element 38 may be, for example, a heat-conducting paste. Preferably, the heat-conducting element 38 is in contact with the outer side of the partition wall 16 or the outer side of the bottom 16a.

[0065] It is possible that the printed circuit board has an electrical connection 39 to the stator 1. It is possible that the printed circuit board 18 is fixed to the stator support in a region diametrically opposite the electrical connection 39. Preferably, electrical connections (not shown) are located on the lower housing part 15b. The printed circuit board 18 can in particular have electronic control elements, such as MOSFETs, which cause a significant part of the heating of the printed circuit board.

[0066] Preferably, the collecting channel 28 or the partition wall 16 or the collar 16c and the rotor 2 or the pump wheel 6 or the wheel disc 36 form a surrounding gap 37. Preferably, a secondary flow of the fluid is branched from the main flow of the fluid through the surrounding gap 37. The secondary flow is suitably subject to the secondary flow path specified by the pump. The secondary flow is formed due to the pressure difference between the radially outer region and the radially inner region. The secondary flow first flows into the upper cavity 11a, and then preferably flows through the annular gap 21. In the further stroke, the secondary flow then advantageously reaches the lower cavity 11b.

[0067] Particularly preferably, the rotor 2 or the rotor body 3 comprises at least one return channel 12 and preferably a plurality of return channels 12 for the secondary flow, which establish a fluid connection between the drive chamber 11 and the wheel chamber 10. It is suitable that the return channels 12 are separated from each other by a partition element 13 of the rotor 2 or a partition element of the rotor body 3. Each return channel 12 preferably comprises a lower section 12b, an upper section 12a and an outlet 12c. Advantageously, the cross-sectional area of ​​the lower section 12b is larger than the cross-sectional area of ​​the upper section 12a.

[0068] The secondary flow flows upward from the lower cavity 11b through the return channel 12 through the rotor 2 or the rotor body 3 back to the wheel chamber 10. At the outlet 12c of the return channel 12, there is a lower pressure than the pressure in the collecting channel 28, so a secondary flow is formed. The secondary flow absorbs heat from the stator 1, the circuit board 18 and the rotor module 4, and mixes with the main flow in the radial inner area of ​​the wheel chamber 10.

[0069] Preferably, the lower section 12b of the return channel 12 at least partially overlaps the rotor module 4 in the axial direction. Therefore, the wall between the rotor module 4 and the lower section of the return channel 12 is relatively thin, so that heat can be dissipated well.

[0070] The return channels 12 are preferably separated from one another along the lower section 12b of the return channels 12 by partition elements 13. The partition elements 13 are particularly Figure 4 1 and can be designed in particular as a web or rib. The separation element 13 expediently connects, on the one hand, the wall of the rotor body 3 between the rotor module 4 and the return channel 12 and, on the other hand, the wall of the rotor body 3 directly surrounding the rotary bearing 5. In this way, the separation element 13 stabilizes the shaft 7 of the rotor 2 or the shaft of the rotor body 3. At the same time, in particular the separation element 13 causes considerable turbulence in the lower cavity 11b, thus generating losses.

[0071] It is very preferred that the rotor 2 has a projection 27 which projects in the radial direction, preferably radially inwards, and at least partially covers the inlet of the return channel 12 or the return channels 12 when viewed from the bottom of the rotor 2. In the present exemplary embodiment, the projection 27 completely covers the inlet of the return channel 12. Figure 1 The inlet of the return channel 12 described in .

[0072] Preferably, the rotor 2 comprises a rotor cover 14, which is preferably fixed to the lower end of the rotor 2. The rotor cover 14 can be connected to the lower side of the rotor body 3, for example by means of ultrasonic welding. Very particularly preferably, the rotor cover 14 comprises a projection 27. The projection 27 or the rotor cover 14 shields the partition element 13 from the cavity 11b below, so that the turbulence is confined to a much smaller space and the losses caused by the turbulence in this area are significantly reduced.

[0073] The rotary bearing 5 preferably comprises carbon and in particular graphite. Preferably, the rotary bearing 5 comprises a binder and in particular a polymer. The shaft 23 has an effective length AL, which corresponds to the axial length of the shaft 23 coming out of the shaft fixing portion 42 or the bottom 16a, and through which a contact surface is provided for the rotary bearing 5. The rotary bearing 5 has an effective rotary bearing length DL, which corresponds to the axial contact length provided between the rotary bearing 5 and the shaft 23. The ratio DL / AL is 0.72 in this embodiment.

[0074] Preferably, a rotor support 22 is arranged in the flow direction between the inlet 8 and the pump wheel 6. The rotor support 22 of this exemplary embodiment comprises three legs, which are fixed to the inner side of the inlet 8. The rotor support 22 preferably has a receptacle 40 on its underside.

[0075] In this embodiment, the shaft support 24 is pressed into the receiving portion 40. The shaft support preferably comprises metal, and in particular steel or high-quality steel. Advantageously, the shaft support 24 of the shaft 23 allows axial sliding, but without radial play. Preferably, the rotary bearing 5 can slide axially on the shaft 23 and can rotate around the shaft 23, but without radial play relative to the shaft 23. The shaft support has an effective length HL in the axial direction, which corresponds to the contact length with the shaft 23. Preferably, the ratio HL / AL is at least 0.07 or 0.10 or 0.12 or 0.14 or 0.16. Very preferably, the sum of DL+HL is at least 0.5 or 0.6 or 0.7 or 0.8 or 0.9 times AL.

[0076] Preferably, the lower housing part 15b comprises a lower housing flange 31b. Advantageously, the lower housing flange 31b abuts against the support flange 30 of the stator support 29. Preferably, the support flange 30 abuts against the partition wall flange 16d. Preferably, the support flange 30 is arranged between the partition wall flange 16d and the lower housing flange 31b. Preferably, the partition wall flange 16d is located between the upper housing flange 31a and the support flange 30 or the lower housing flange 31b.

[0077] It is very preferred that the upper housing flange 31a, the partition wall flange 16d, the support flange 30 and / or the lower housing flange 31b are pressed against each other by means of a fixing device. The fixing device is preferably a screw connection. It is very particularly preferred that the fixing device 41 or the screw device passes through the upper housing flange 31a, the partition wall flange 16d, the support flange 30 and / or the lower housing flange 31b.

[0078] It is possible that the pump has at least one support seal 20b and preferably two support seals 20b. In this embodiment, a support seal 20b is arranged between the stator support 29 and the lower housing part 15b in the length section of the pump. It is possible that a support seal 20b is arranged between the stator support 29 and the partition wall 16.

[0079] exist Figure 2 1 shows the bottom 16a of the partition wall 16 in a perspective view, so that the preferably star-shaped arrangement of the ribs 17 of this embodiment can be seen. Each rib 17 preferably extends with its longitudinal extension from the radial outer area of ​​the bottom 16a to the radial inner area of ​​the bottom 16a or to the shaft fixing portion 42 located at the radial center of the bottom 16a. The lower end of the shaft 23, which is surrounded by the shaft fixing portion 42 and injection-molded, can have an asymmetry, for example, a groove, thereby ensuring the rotationally fixed fixation of the shaft 23 in the bottom 16a or in the shaft fixing portion 42. This stable bottom structure or shaft fixing portion 42, combined with the also stable shaft support 24, allows precise positioning of the shaft. Therefore, in particular, a high running quietness of the rotor 2 around the shaft 23 is ensured, which is especially supported by the very long extended rotary bearing 5. As a result, a high running quietness and low wear are achieved.

[0080] In addition Figure 2 The structure of the rotor cover 14 can be seen somewhat better in FIG. A further projection of the rotor cover extends in the axial direction into the return channel 12 or into the return channels 12 . The further projection essentially has the purpose of correctly positioning the rotor cover 14 on the rotor 2 .

[0081] exist Figure 3 The top view of the rotor body 3 is depicted in FIG. 1 , so that the upper section 12a and the outlet 12c of each return channel 12 are visible. Preferably, each outlet is assigned to a blade 19 or a blade channel 43. Preferably, each blade 19 includes a blade 19 on its upper side for contacting with the blade 12c. Figure 3 Preferably, the rotor body 3 includes a coupling element on its radial inner side, which is coupled to the wheel cover 25 not described in the figure. Figure 3 The rotary bearing 5 not shown in the figure is engaged. In this embodiment, the rotary bearing 5 comprises four axially extending grooves on its outer side, which are connected to the rotary bearing 5 on the outer side. Figure 3 The engagement elements 26 of the rotor body 3 in the embodiment are designed to be complementary.

[0082] Finally Figure 4, the underside of the rotor body 3 is shown, the rotor cover 14 being omitted for the sake of simplicity, like all other elements except the rotor body 3. The return channel 12 and the separator element 13 are now clearly visible. The separator element 13 is preferably designed in the form of a web. Advantageously, the separator element 13 extends in the tangential direction in the cross section of the rotor body 3. The separator element 13 is rotated in the clockwise direction, so that the selected tangential orientation of the separator element 13 forms a first measure for reducing turbulence. This measure is also achieved in particular by Figure 4 The rotor cover 14 described in the above is supplemented.

[0083] exist Figure 4 It can be clearly seen that the lower section 12b of each return channel 13 is preferably significantly larger in its cross-sectional area than the upper section 12a of the corresponding return channel 12. The lower section 12b of the return channel 12 provides a large volume in order to cool the rotor module 4 as well as possible. The larger volume of the lower section 12b of the return channel 12 is only possible at the expense of thinner partition elements 13 or thinner inner walls of the rotor body 3, which rest against the rotary bearing 5. The upper sections 12a of the return channel are therefore relatively small on the one hand, so that these upper sections can be better allocated to the individual blade channels 43. Reference numerals list

[0084] ARotation axis

[0085] 1 Stator

[0086] 2 Rotors

[0087] 3 Rotor body

[0088] 4 rotor modules

[0089] 5. Rotary bearing

[0090] 6 Pump wheel

[0091] 7-axis

[0092] 8Entrance

[0093] 9Exit

[0094] 10 round room

[0095] 11Drive room

[0096] Cavity above 11a

[0097] The cavity below 11b

[0098] 12Return channel

[0099] Section above 12a

[0100] 12b The section below

[0101] 12c Exit

[0102] 13 Separation elements

[0103] 14 rotor cover

[0104] 15 Shell

[0105] 15a Housing part above

[0106] 15b Shell part below

[0107] 16 Partition wall

[0108] 16a bottom

[0109] 16b side wall

[0110] 16c collar

[0111] 16d Divider wall flange

[0112] 17 Ribs of the partition wall

[0113] 18 Circuit Board

[0114] 19 Pump impeller blades

[0115] 20a fluid seal

[0116] 20b bracket seal

[0117] 21 Annular gap

[0118] 22 rotor bracket

[0119] 23 Axis

[0120] 24 axis bracket

[0121] 25 rotor wheel cover

[0122] 26 Engagement element of rotor body

[0123] 27Protrusions on the rotor and rotor cover

[0124] 28 Collection Channels

[0125] 29 stator bracket

[0126] 30 bracket flange

[0127] 31a Upper housing flange of the upper housing part

[0128] 31b The lower housing flange of the lower housing part

[0129] 32 Magnets

[0130] 33 rotor core

[0131] 34 stator core

[0132] 35 stator winding

[0133] 36 Roulette

[0134] 37 Surrounding gap

[0135] 38 Thermal Conductive Components

[0136] 39 Electrical connection structure

[0137] 40 Receiving portion of rotor support

[0138] 41 Fixtures

[0139] 42 axis fixing part

[0140] 43 blade channel

[0141] 44 module housing

Claims

1. A pump for driving a fluid, in particular a temperature-control medium, the pump being particularly used in a vehicle, particularly preferably used for controlling the temperature 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), a rotor module (4) and a rotary bearing (5), the rotor (2) being rotatably supported about a rotation axis (A), the rotor (2) or the rotor body (3) having a pump wheel (6) and a shaft (7), the rotor (2) or the rotor body (3) comprising a module housing (44) which at least partially surrounds the rotor module (4), at least one section of an inlet (8) of the pump being arranged in an axial upper half of the pump, and the pump comprising an outlet (9).

2. The pump according to claim 1, wherein The pump comprises a housing (15) and a partition wall (16), wherein the partition wall (16) divides the space within the housing (15) into a wet area and a dry area, preferably, the wet area has a wheel chamber (10) and a drive chamber (11), the pump wheel (6) is located in the wheel chamber (10), and preferably, the module housing (44) is arranged in the drive chamber (11).

3. The pump according to claim 1 or 2, wherein: The pump wheel (6) is arranged between the inlet (8) and the outlet (9) in the flow direction of the main flow path of the fluid. Preferably, the pump is configured so that a secondary flow path of the fluid branches off from the main flow path, and the secondary flow path extends from the wheel chamber (10) to the drive chamber (11).

4. The pump according to claim 3, wherein: The rotor (2) or the rotor body (3) has at least one return channel (12) and preferably a plurality of return channels (12) for the secondary flow, wherein the return channels establish a fluid connection between the drive chamber (11) and the wheel chamber (10), and the return channels (12) are preferably separated from each other by a partition element (13) of the rotor (2) or a partition element of the rotor body (3).

5. The pump according to any one of claims 1 to 4, wherein: The pump comprises a rotationally immovable shaft (23), on which the rotor (2) is preferably rotatably mounted.

6. A pump according to any one of claims 1 to 5, wherein: The rotor (2) has a projection (27) for reducing turbulence in a length section of the pump, which projection (27) projects in the radial direction and preferably at least partially covers the inlet of the return channel (12) when viewed towards the underside of the rotor (2).

7. A pump according to any one of claims 1 to 6, wherein: The rotor (2) has a rotor cover (14) which is fixed to the lower end of the rotor (2).

8. A pump according to any one of claims 1 to 7, wherein: The rotor body (3) is designed in one piece and preferably in one piece.

9. A pump according to any one of claims 1 to 8, wherein: The module housing (44) surrounds the rotor module (4) in the radial direction at least along an axial section and at least along a circumferential section.

10. A pump according to any one of claims 1 to 9, wherein The pump comprises a circuit board (18) for controlling the operation of the pump. Preferably, the circuit board (18) is arranged on the outer side of the partition wall (16).

11. A pump according to any one of claims 4 to 10, wherein The return channel (12) is located within the rotor (2) or the rotor body (3); preferably, the rotor (2) or the rotor body (3) completely surrounds at least one return channel (12) at least partially in the axial direction and in cross section.

12. A pump according to any one of claims 5 to 11, wherein The rotary bearing (5) has an effective axial rotary bearing length DL, the shaft (23) has an effective shaft length AL, and the ratio DL / AL is greater than or equal to 0.4, preferably greater than or equal to 0.5, and further preferably greater than or equal to 0.

6.

13. A pump according to any one of claims 5 to 12, wherein The rotary bearing (5) bears against the shaft (23) over the entire circumference along at least one axial section or has no groove.

14. A pump according to any one of claims 5 to 13, wherein The pump has a shaft support (24), and preferably, the shaft support (24) is arranged in the upper half of the shaft (23), or in the upper 1 / 3 of the shaft, or in the upper 1 / 4 of the shaft.

15. A pump according to any one of claims 1 to 14, wherein A rotor support (22) is arranged between the inlet (8) and the pump wheel (6) in the flow direction. Preferably, the rotor support (22) is fastened to the housing (15) or to an upper housing part (15a).

16. A pump according to any one of claims 2 to 15, wherein An annular gap (21) extends between the radial outer side of the drive section (19) of the shaft body (7) and the inner side of the partition wall (16), preferably so that the secondary flow path fluidically connects the upper cavity (11a) of the drive chamber (11) with the lower cavity (11b) of the drive chamber (11).

17. A pump according to any one of claims 2 to 16, wherein The partition wall (16) has a plurality of ribs (17) on the inner side in the lower region of the drive chamber (11).

18. A pump according to any one of claims 2 to 17, wherein The partition wall (16) comprises a thermoplastic, preferably the partition wall (16) comprises a thermal conductivity additive for increasing the thermal conductivity.

19. A pump according to any one of claims 1 to 18, wherein The pump comprises a stator support (29), preferably the stator support (29) has a support flange (30), preferably the support flange (30) rests on a housing flange (31a, 31b).

20. A pump according to any one of claims 2 to 19, wherein The pump comprises a lower housing part (15b), a stator assembly, a partition wall assembly and an upper housing part (15a), wherein the stator assembly has the stator (1) and preferably has a stator bracket (29), and the partition wall assembly has the partition wall (16) and preferably has a shaft (23). The pump can be assembled in the following order: the lower housing part (15b), the stator assembly, the partition wall assembly, the rotor (2), and the upper housing part (15a), or can be assembled in the reverse order.

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