Temperature control pump

Abstract

To provide a temperature control medium driving pump which is configured for thermal management of an electric vehicle and achieves higher performance and low costs at the same time.SOLUTION: A pump comprises a stator 1 and a rotor 2. The rotor has a rotor body 3, a rotor block 4 as well as a rotary bearing 5. The rotor or the rotor body comprises a pump wheel 6 and a shaft 7. The rotor body has a block casing 44. The block casing at least partly encases the rotor block. For a secondary flow, the rotor preferably has several return guide passages 12. The return guide passages establish a fluidic connection between a drive chamber 11 and a wheel chamber 10. The pump preferably comprises a rotationally non-movable axle 23. The rotor is rotatably mounted on the axle 23.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pump for driving a fluid, preferably a temperature control medium, in particular for use in a vehicle, in particular for temperature control of a drive battery in an electric vehicle, the pump comprising a stator and a rotor, the rotor having a rotor body, a rotor block and a rotary bearing, the rotor being rotatably supported about a rotation axis, the rotor or the rotor body having a pump wheel and a shaft, the rotor or the rotor body having a block casing which at least partially encases the rotor block, at least a part of the pump's intake is arranged in the axially upper half of the pump and the pump has a discharge port. [Background technology]

[0002] EP 1 339 633 A1 discloses an electrically driven cooling medium pump with an outer stator and an inner rotor. The rotor has a rotor body, upper and lower rolling bearings and a rotor block with magnets. The rotor block is partially enclosed by a block casing. The rotor body has a pump wheel and a shaft. The shaft has a connection section and a block casing, which axially connects the block casing and the pump wheel. The rotor body is formed as an injection molded part and thus in one piece, and the block casing axially surrounds the magnets. Both bearings are formed as plain rolling bearings and allow the rotor to rotate around the axle with low friction. The upper bearing is additionally designed as a tilting bearing in order to minimize friction between the upper axle holder and the upper plain bearing. During operation, the stator, the rotor and the control electronics of the pump heat up and require cooling. Cooling is ensured by a secondary flow path, which has a return guide channel tightly fitted in the rotor block, which is located exactly at the point where the lower rolling bearing has the least radial projection, thus optimizing the use of the space in the rotor body or shaft.

[0003] EP 1 339 633 A1 describes a cooling medium pump that also has a secondary flow path. For this purpose, the rotor has a number of return guide passages that cool the rotor block from its radial inner surface. This allows the rotor block to be cooled even better, while at the same time the rotor imbalance is reduced and wear is reduced due to the number of return guide passages. The rotor block is mounted on a central rotor shaft, so that the rotor shaft is rotatably supported in the central wall. The rotor shaft passes through the central wall and drives the pump wheels. For this purpose, the central wall has fixed rotary bearings in which the rotor shaft can rotate. Due to limited construction space, these rotary bearings do not overlap axially with the return guide passages provided in the rotor body. Instead, the rotary bearings have axially extending grooves on their inner surface, which follow the flow direction of the secondary flow towards the return guide passages of the rotor. These fixed grooves connect the rotating return guide passages of the rotor body to the wheel chamber, in which the secondary flow mixes with the main flow. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent Application Publication No. 3318765 [Patent Document 2] DE 102018125031 A1 Summary of the Invention [Problem to be solved by the invention]

[0005] These known coolant pumps are designed to cool an internal combustion engine and are only operated at full load once the internal combustion engine has been running for some time and is warmed up. In this case, the known coolant pumps are assisted in particular by the running wind. The object of the present invention is therefore to design a pump for the thermal management of electric vehicles ("thermostat pump"), and thus to design it more efficiently and at the same time more cost-effectively.

[0006] The energy transition and the mobility shift require the expansion of new technologies, including in particular electric vehicles with a traction battery and an electric motor. The traction battery achieves maximum efficiency at a temperature of around 20° C. and must be heated or cooled depending on the situation. Heating is expedient especially in winter, immediately after starting, whereas cooling is considered especially after the vehicle has already been running for some time. In this respect, the thermal management of the powertrain in electric vehicles differs from that of combustion-based vehicles, especially in cold weather. After all, the entire component chain of the thermal management in electric vehicles (pipes, quick connectors, pumps, battery casing, etc.) must additionally be designed to work in cold weather and also without the assistance of road air. This means that a relatively large flow rate of the temperature-regulating fluid in electric vehicles is required all year round. As a result, the cooling or temperature-regulating pumps must be designed with correspondingly high performance. [Means for solving the problem]

[0007] The above-mentioned object is achieved by a pump for driving a fluid, preferably a temperature control medium, in particular for use in a vehicle, in particular for temperature control of a drive battery in an electric vehicle, the pump having a stator and a rotor, the rotor having a rotor body, a rotor block and a rolling bearing, the rotor being supported for rotation about a rotation axis, the rotor or the rotor body having a pump wheel and a shaft, the rotor or the rotor body having a block casing, which at least partially encases the rotor block, at least a part of the pump's intake is arranged in the axially upper half of the pump, and the pump has a discharge, which makes it possible to design the pump in such a way that the object mentioned at the beginning is achieved.

[0008] Preferably, the pump comprises a casing and a partition wall, which divides the space in the casing into a wet area and a dry area. The wet area advantageously comprises a wheel chamber and a drive chamber, the pump wheel being present in the wheel chamber. Preferably, the block casing is arranged in the drive chamber. The pump can comprise a base plate for controlling the pump operation. Expediently, the stator and / or the base plate are present in the dry area. This allows protection of the electrical / electronic components while at the same time allowing a flow around the rotor.

[0009] Preferably, the pump wheel is arranged between the inlet and the outlet in the direction of flow of the main fluid flow path. Advantageously, the pump is designed such that a secondary fluid flow path branches off from the main fluid flow path and runs from the wheel chamber into the drive chamber. This allows cooling of the stator, rotor or rotor block and / or the substrate.

[0010] According to a highly preferred embodiment, the rotor or rotor body has at least one, preferably several, return guide passages for the secondary flow, which form a fluid connection between the drive chamber and the wheel chamber. Expediently, the return guide passages are separated from one another via a separation element of the rotor or rotor body. The invention is based on the recognition that, in particular critical from the performance point of view, wear as little as possible is essential for reducing the probability that the pump has to be repaired during the life of the electric vehicle. It has been found that wear occurs especially on the rotor's rolling bearings. This wear is related not only to the total working work (average number of revolutions over the life of the pump) but also to the resulting imbalance in the rotor. The invention is based on the recognition that the provision of several return guide passages in the rotor significantly reduces the imbalance of the rotor, which ultimately reduces the wear, increases the total working work and improves the performance of the pump.

[0011] Particularly preferably, the pump comprises a rotationally stationary axle, and the rotor is rotatably supported on the axle, which allows particularly low wear on the rotary bearing and increases the service life. The axle preferably comprises metal, more preferably steel, in particular high-grade steel.

[0012] The invention is based on the recognition that a solid shaft without an axial through-hole for an axle can only be supported in an external rotary bearing in an axial portion, since the other axial portion of the solid shaft has to perform another function, in particular is assigned to a rotor block or a pump wheel, and as a result the axial length of the external rotary bearing of the solid shaft is relatively short compared to the overall length of the shaft.

[0013] In contrast, in the case of an axle, the rotor block and the rolling bearing or the internal rolling bearing can overlap in the axial direction over a longer portion, so that in the case of a system with an axle, a relatively larger rolling bearing length can be achieved. As a result, in the case of an axle system, the rotor runs quieter overall, which leads to less wear, a longer service life and, as a result, a higher performance pump. As a result, the problem mentioned at the beginning is solved.

[0014] The axis of rotation A defines axial, radial and tangential or circumferential directions. The circumferential direction preferably relates to a view from above and thus to a view looking into the suction from the outside. The direction of rotation of the rotor expediently extends in the clockwise circumferential direction. The expression "axially inward" preferably relates to the direction of flow of the fluid in the suction. The direction of flow of the fluid in the suction just before the pump wheel or spider is preferably directed from "above" to "below". The expression "axially inward" is therefore equivalent to the expression "from above to below".

[0015] The rotor block preferably comprises a rotor core. The rotor block preferably comprises magnets, in particular permanent magnets. Expediently, the rotor block or the rotor core is formed in an approximately ring-shaped cross section. The magnets are preferably attached to the radially outer surface of the rotor core. Very preferably, the rotor core comprises a plurality of rotor sheet metals stacked one on top of the other. The rotor sheet metals are preferably electrical steel sheets. The rotor sheet metals can be joined to one another by stamping or by adhesive coating to form the rotor core. It is advantageous if the rotor sheet metals are provided with an insulating coating.

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

[0017] The rolling bearing can be subjected to a sliding rolling movement at its radially inner surface or at its radially outer surface. The rolling bearing can be made of the same material as the rotor body, in particular it can be an integral part of the rotor body. The rolling bearing can also be made of a different material than the rotor body.

[0018] Preferably, the casing has an upper casing part and a lower casing part. The base plate is arranged, in particular in the axial direction, preferably between the partition wall and the lower casing part. The stator is arranged, in particular in the radial direction, preferably between the partition wall and the lower casing part. The rotor is preferably located, in particular in the axial direction, between the upper casing part and the partition wall.

[0019] The partition preferably has a bottom, a side wall, a collar and / or a partition flange. The upper casing part preferably has an upper casing flange. The lower casing part preferably has a lower casing flange. The pump preferably comprises a stator holder. The stator and the stator holder preferably form a stator unit. The stator holder preferably has a holder flange.

[0020] The intake is particularly preferably formed coaxially relative to the rotor. This results in low pressure losses in the pump wheel. A collecting passage is preferably arranged around the circumference of the pump wheel and collects the fluid displaced radially outward. The collecting passage preferably has an inside cross-sectional area that increases in a clockwise direction. This results in a constant pressure being provided along the collecting passage, which at the same time also generates a relatively constant pressure gradient radially inward along the collecting passage. The discharge is preferably formed as a tangential extension of the circumferential passage. This results in low pressure losses.

[0021] According to a particularly preferred embodiment, the rotor, viewed in a longitudinal section of the pump, has a turbulence-reducing protrusion that protrudes radially and at least partially, preferably completely, conceals an inlet of a return guide passage, preferably all inlets of the return guide passages, in the direction of view towards the underside of the rotor. This results in the shielding of the return guide passage or passages and the separation element from the lower cavity, so that these elements that generate turbulence have only a small effect on the amount of fluid in the lower cavity. This allows the rotor or the pump to run more smoothly overall and reduces the current consumption of the pump. Preferably, the protrusion forces the fluid in the region of the return guide passage inlet or the return guide passage inlets to deviate from a pure axial flow direction. Advantageously, the protrusion changes the return guide passage inlet or the return guide passage inlets in such a way that the surface normal of the inlet's active surface or inner surface deviates from a pure axial extension. Very particularly preferably, the surface normal of the inlet into the return guide channel runs in a radial or purely radial direction, in particular in an outward radial direction or in an outward purely radial direction.

[0022] Very preferably, the rotor has a rotor cap, which is attached to the lower end of the rotor. The rotor cap can be attached to the rotor or to the rotor body, for example, by ultrasonic welding. Particularly preferably, the rotor cap has a protrusion that reduces turbulence. This allows for simplification of the injection molding technique of the rotor body.

[0023] It is highly advantageous if the rotor body is formed in one piece, preferably integrally, in particular by injection or insert molding. Being in one piece provides a relatively high stability, which is important in terms of the service life and therefore the high total number of revolutions. The integral construction of the rotor body in the form of injection or insert molding significantly reduces the number of parts and joining steps, thus keeping the manufacturing effort or costs low.

[0024] The pump wheel preferably has a wheel disk and / or vanes for guiding the fluid. The vanes are preferably connected to the wheel disk in one piece, in particular integrally. The rotor body preferably has the wheel disk and / or vanes. The vanes form vane passages between the vanes in a purposeful manner. The rotor or rotor body or pump wheel preferably has 5, particularly preferably 7 vanes or vane passages.

[0025] The rotor preferably has a wheel cover. The wheel cover and the rotor body or the vanes are suitably mated and / or welded to one another. The wheel cover is suitably used to close the pump wheel upwards, so that only the upper surface of the wheel cover and not the vanes can come into contact with the upper housing part. This virtually eliminates wear on the vanes, which extends the service life of the pump.

[0026] Very particularly preferably, the rotor body or block casing surrounds the rotor block radially, at least along an axial portion and at least along a circumferential portion. Preferably, the rotor body or block casing surrounds the rotor block radially, along the entire axial extension of the rotor block and / or along the entire circumference of the rotor block. This shields the metallic components of the rotor block from the fluid. Furthermore, surrounding the rotor block with the rotor body or block casing serves to smooth the outer surface of the rotor block, so that the metallic parts of the rotor block do not damage the partition wall. And finally, surrounding the rotor block results in a particularly smooth outer radial surface of the drive section of the rotor, which reduces the turbulence generated by the drive section to a minimum.

[0027] According to a very preferred embodiment, the substrate is arranged on the outer side of the partition wall. Preferably, the substrate comprises an electronic control unit, for example a transistor, in particular a MOSFET. It is advantageous for the substrate to be arranged on the bottom of the partition wall. Very preferably, a heat conducting element is present between the substrate and the partition wall. The heat conducting element advantageously comprises a heat conducting paste. Preferably, the electronic control unit is in contact with the heat conducting paste or with the heat conducting element. This ensures a particularly advantageous dissipation of the heat generated in the substrate. Preferably, the substrate comprises an electrical connection which is connected to the stator. Preferably, the electrical connection is mechanically supported by the support element. Thus, from a mechanical point of view, the substrate is mechanically held not only via the electrical connection with the stator, but also via the support element. Preferably, the substrate comprises a second support element. The second support element is arranged in an area of ​​the substrate which is located on the opposite side of the substrate to the area of ​​the first support element with respect to the axis of rotation A. The second support element expediently connects the substrate to the stator or to a stator holder or to a stator unit.

[0028] It is advantageous if the return guide passage is present in the rotor or in the rotor body. Advantageously, the rotor or in the rotor body completely surrounds at least one, preferably all, return guide passages in cross section, at least in an axial portion. The complete surrounding of the return guide passage or passages by the rotor body, respectively, results in the boundary surfaces in the rotor (for example between the rotor body and the rotor block or between the rotor body and the rolling bearing) being particularly uniformly formed. As a result, fewer edges are produced, so that the rotor is more stable and, in particular, wears less. This applies in particular to boundary surfaces which slide against one another during pump operation. However, this also applies to boundary surfaces in the rotor which do not slide against one another. If grooves are present there, they often result in edges or generally undesirable artifacts, so that, for example, the flow behavior of the fluid in the return guide passage can be disturbed.

[0029] According to a particularly preferred embodiment, the rolling bearing has an effective rolling bearing length DL in the axial direction and the axle has an effective axle 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 rolling bearing length in the axial direction" preferably means the axial length of the rolling bearing surface in contact with the axle. The expression "effective axle length" preferably means the axial length of the axle which projects from the bottom of the partition wall and which at the same time provides a contact surface for the rolling bearing or the axle carrier. For example, a chamfer provided at the upper end of the axle does not count towards the effective axle length AL. In particular, the axial part of the axle which is surrounded by the partition wall or by the bottom of the partition wall does not count towards the effective axle length. A ratio DL / AL that is as large as possible minimizes wear, since the forces acting on the rolling bearing and the axle are distributed over a very large surface or a very long extension of the rolling bearing.

[0030] Very particularly preferably, the pump is provided with an axle holder. Advantageously, the axle holder is arranged in the upper half or upper third or upper quarter of the axle. The axle holder preferably comprises metal, more preferably steel, in particular high-grade steel. Very preferably, the axle holder at least partially, preferably completely, surrounds the axle in the circumferential direction. Preferably, the axle is axially slidable in the axle holder, at least in the partially disassembled state of the pump, and at the same time advantageously has no radial play in the axle holder.

[0031] The axle holder has an effective axial retention length HL. The term "effective axial retention length" preferably means the axial length of the axle holder, along which the axle holder is in contact with the axle. In particular, the chamfer on the radially inner surface of the axle holder does not contribute to the effective axial retention 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 ensures that the axle is held particularly stably at its upper end, which results in a quieter operation and less wear.

[0032] It is highly advantageous if the ratio (DL+HL) / AL reaches at least 0.5 or 0.6 or 0.7 or 0.8 or 0.9. This ensures that the effective axle length that remains unused is as small as possible. One realization of the invention is that the effective axle length AL provided by the axle should be utilized as much as possible, in particular for the rolling bearing that is as long as possible in the axial direction and for the axial support that is as long as possible in the axial direction. The ratio DL / HL advantageously reaches 1 to 10, preferably 2 to 7, more preferably 2.5 to 5, and very particularly preferably 3 to 4.

[0033] It is advantageous if the rotor has a small axial play on the axle in the standstill state of the pump or in the absence of fluid. The rotor can not rest against the axle holder in the standstill state or in the absence of fluid. Very preferably, the pump is designed in such a way that during pump operation, the rotor or the rotor body or the rolling bearing rests with its upper axial end face against the lower axial end face of the axle holder. Expediently, the upper axial end face of the rolling bearing and the lower axial end face of the axle holder are exposed to sliding friction against each other. Very preferably, the upper axial end face of the rolling bearing is identical in terms of its surface extent to the surface extent of the lower axial end face of the axle holder. The axial play allows a secondary flow, the strength of which is different depending on the rotational speed and thus depending on the pressure generated. When the pressure in the collecting passage is high, a correspondingly strong secondary flow also generates a higher pressure in the drive chamber, which raises the rotor up to a maximum of abutting against the axle holder. This allows the cooling of the electrical components to be adapted depending on the pump power.

[0034] Preferably, the radial extension of the upper axial end face of the rolling bearing is greater than the radial extension of the rolling bearing in the lower region. Preferably, the rolling bearing has a flange in the upper half or upper third or quarter. This allows a good form-fit with the rotor body and increases the stability of the rotor.

[0035] Very preferably, the rotary bearing rests against the axle over the entire circumference, at least along the axial portion, or is groove-free, so that the rotary bearing is made particularly stable, although it additionally has to fulfill the role of fluid guiding on its inner surface.

[0036] Preferably, the rolling bearing comprises a material different from the rotor body or the shaft or the pump wheel. The rolling bearing advantageously comprises carbon, in particular graphite. The rolling bearing preferably comprises a binder, in particular a polymer. It is advantageous that the rolling bearing is not integrally connected to the pump wheel or is not an integral part of the rotor body. This is achieved on the one hand that the rotor is provided with good sliding properties via the rolling bearing, which has a material optimized for sliding friction. At the same time, the material of the rotor body is optimized for force transmission, in particular for the transmission of torsional forces, so that for the rotor body or the shaft a material different from that for the rolling bearing is considered. The rotor body advantageously comprises a thermoplastic, preferably an engineering thermoplastic, more preferably a high-performance thermoplastic, for example polyphenylene sulfide (PPS).

[0037] Advantageously, a spider is arranged between the intake and the pump wheel in the flow direction. The spider is preferably attached to the casing or to the upper casing part. The spider preferably has at least two, more preferably at least three, legs. Very particularly preferably, the spider has exactly three legs. The legs of the spider are preferably arranged on or attached to the inner surface of the intake. It is advantageous if the spider is connected in one piece, preferably integrally, to the intake or to the upper casing part or to the casing. The spider expediently has a receiving part on the underside of the spider, into which the axle holder is inserted. Preferably, the axle holder is press-fitted into the receiving part of the spider. The spider thereby enables the axle holder to be attached to the casing with relatively low turbulence.

[0038] According to a preferred embodiment, an annular gap extends between the radially outer surface of the drive section or block casing and the inner surface of the partition or the inner surface of the side wall of the partition. The secondary flow path advantageously includes the annular gap. Preferably, the annular gap fluidly connects the upper cavity of the drive chamber to the lower cavity of the drive chamber. This causes the fluid to cool the inner surface of the stator and the outer surface of the rotor block.

[0039] Preferably, the pump wheel or wheel disk and the collecting passage or the partition or the partition collar form an encircling gap, which fluidically connects the collecting passage or the wheel chamber to the drive chamber or to the upper cavity of the drive chamber. This encircling gap allows the passage of the relevant liquid volume on the basis of an almost complete revolution, so that the stator, the rotor block and the substrate are sufficiently cooled. At the same time, this encircling gap allows the avoidance of turbulence. For example, if there are several defined passages from the collecting passage into the upper cavity, each inlet and each outlet would generate turbulence. As a result, this encircling gap is, overall, somewhat more advantageous from a fluid dynamics point of view than individual passages.

[0040] According to a particularly preferred embodiment, the partition wall has ribs on its inner surface, preferably in the region below the drive chamber. Expediently, the ribs are arranged on the inner surface of the bottom of the partition wall. This provides reinforcement of the bottom or the partition wall and thus improves the stability of the axle. This in turn promotes quieter running of the pump and reduces wear. Furthermore, the ribs are advantageous compared to a solid bottom design, since thick-walled regions are more likely to lead to defects during injection molding. Defects include, in particular, porosity and material shrinkage. The ribs preferably extend radially with the longitudinal extension of the ribs.

[0041] Advantageously, the partition or the bottom of the partition has an axle fastening on the inner surface of the partition or bottom. The axle fastening is expediently arranged in the center of the bottom or partition when viewed in longitudinal section. Preferably, the axle fastening is a one-piece, in particular integral, part of the bottom or partition. Very particularly preferably, the axle fastening is formed by insert molding of the axle. Advantageously, the axle has an asymmetrical region in the axial part that is insert molded to be enveloped by the axle fastening. This serves to prevent the axle from rotating in the axle fastening or in the bottom or partition.

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

[0043] Advantageously, the pump comprises a stator holder. Preferably, the stator holder has a holder flange. Preferably, the holder flange rests against a casing flange, in particular against an upper casing flange and / or a lower casing flange, particularly preferably against the lower casing flange. This allows a very quick assembly of the pump, since the stator holder can be inserted into the lower casing part together with the entire stator. Advantageously, the holder flange rests against a partition flange. Expediently, the holder flange is arranged axially between the partition flange and the lower casing flange. Preferably, the partition flange rests against the upper casing flange and / or the holder flange. Preferably, the partition flange is arranged between the upper casing flange and the holder flange or the lower casing flange. Preferably, a mounting device, in particular a screw device, clamps together or penetrates and engages the upper casing flange, the partition flange, the holder flange and / or the lower casing flange, which allows for a quick fixing of all the larger components of the pump.

[0044] According to one highly preferred embodiment the pump comprises a lower casing part, a stator unit, a partition wall unit and an upper casing part, the stator unit comprising a stator and preferably a stator holder, the partition wall unit comprising a partition wall and preferably an axle, the pump comprising: The lower casing part, Stator unit, Partition wall unit, Rotor, The upper casing part, The rotors can be assembled in this order or in the reverse order. The fact that both of these orders are possible does not exclude other orders. For example, the rotor can be placed on the axle of the partition unit and then the partition unit together with the rotor can be placed on the stator unit.

[0045] It is advantageous for the stator unit to have a base plate. According to a preferred embodiment, the lower housing part has an external electrical terminal. Very preferably, the external electrical terminal can be connected or is connected to the base plate via a cable. Expediently, the cable is connected to the lower housing part and to the base plate before the stator unit is installed in the lower housing part or the lower housing part is installed on the stator unit.

[0046] The present invention will be described in detail below with reference to an embodiment and the accompanying drawings. [Brief description of the drawings]

[0047] [Figure 1] 1 is a vertical cross-sectional view of a pump according to the present invention. [Diagram 2] FIG. 2 is an enlarged perspective view of a part of FIG. 1 cut away. [Diagram 3] FIG. 2 is a top view of a rotor body of the pump shown in FIG. [Figure 4] FIG. 2 is a bottom view of the rotor body shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] 1 shows a pump, which is preferably used for thermostating in a vehicle, particularly preferably the drive battery of an electric vehicle, in particular a thermostat pump which drives a thermostating medium through a fluid line to the drive battery of the electric vehicle.

[0049] The pump expediently comprises an inlet 8 and an outlet 9, which is only shown in broken lines in FIG. 1 due to the selected cross section. The pump comprises a pump wheel 6, which operates clockwise. As a result, the fluid coming from the inlet 8 is displaced outwards and advantageously into the surrounding collecting passage 28. The inside cross section of the collecting passage 28 preferably expands clockwise to the outlet 9, so that the pressure in the collecting passage 28 can be kept approximately constant along the preferably approximately complete circumference of the collecting passage 28. The path of the fluid from the inlet 8 to the outlet 9 via the pump wheel 6 and the collecting passage 28 is the main flow path provided by the pump for the fluid. The pump wheel 6 in this embodiment has a total of seven vanes 19, which displace the fluid radially outwards.

[0050] The pump is driven electrically and for this purpose comprises a stator 1 and a rotor 2. The rotor 2 is suitably arranged in the stator 1. The stator 1 may comprise a stator core 34, which is shown in a simplified form, and a stator winding 35, which is also shown in a simplified form. The stator core 34 may be formed in a known manner as a surrounding ring with a number of pole shoes. The stator core 34 may be formed from a stack of a number of stator sheet metals. The stator 1 is preferably arranged on or against a stator holder 29. The pump suitably comprises a casing 15, which in the present embodiment comprises an upper casing part 15a and a lower casing part 15b.

[0051] The rotor 2 comprises a rotor body 3, a rotor block 4, a rolling bearing 5 and / or a pump wheel 6. The rotor 2 is preferably supported rotatably about a rotation axis A on a rotationally fixed axle 23. The axle 23 preferably comprises a metal, more preferably a steel, in particular a special steel. Preferably, the axle 23 is tapered at the upper end of the axle 23 via a chamfer.

[0052] The rotor 2 in this embodiment has a wheel cover 25, which closes or covers the pump wheel 6 towards the suction opening 8 or upwards. The wheel cover 25 can have a central opening. The pump wheel 6 is suitably located in a wheel chamber 10 formed by the casing 15. Very preferably, the rotor 2 or rotor body 3 or pump wheel 6 has a number of, preferably seven, vanes 19 and / or one wheel disc 36.

[0053] The rotor block 4 of this embodiment has a rotor core 33 and, appropriately, a plurality of magnets 32. The magnets 32 can be configured in a rectangular parallelepiped shape or slightly curved shape, and are preferably arranged on the radial outer surface of the rotor core 33.

[0054] The rotor 2 or rotor body 3 preferably has a block casing 44 which at least partially, in this embodiment completely, encases the rotor block 4. The rotor body 3 or block casing 44 advantageously comprises plastic and is preferably manufactured by insert-molding the rotor block 4 and / or the rolling bearing 5.

[0055] The rotor 2 or rotor body 3 advantageously comprises a shaft 7. Preferably, the shaft 7 comprises a drive section and / or a coupling section in the axial direction. Advantageously, the drive section comprises a block casing 44. Preferably, the coupling section is arranged in the axial direction between the drive section or block casing 44 and the pump wheel 6 or wheel disc 36.

[0056] The pump preferably comprises a partition 16. The partition 16 preferably comprises a plastic, in particular an engineering plastic, more preferably a high-performance plastic, in particular polyphenylene sulfide (PPS). Advantageously, the partition 16 comprises a conductive additive which improves the thermal conductivity. The conductive additive may in particular comprise a plastic, preferably graphite. Advantageously, the partition 16 is formed in one piece, in particular integrally. The partition 16 preferably comprises a bottom 16a, a side wall 16b, a collar 16c and / or a partition flange 16d.

[0057] The partition wall 16 or the bottom part 16a preferably has an axle fixing part 42. The axle fixing part is advantageously connected to the bottom part 16a or the partition wall 16 in one piece, in particular integrally. The axle 23 is preferably fixed in the partition wall or in the bottom part 16a, in particular by the axle fixing part 42. The axle fixing part 42 is advantageously formed around the lower end region of the axle 23 by insert molding. The bottom part 16a in this embodiment has a number of ribs 17, which reinforce the bottom part 16a or the axle fixing part 42.

[0058] The side wall 16b or the partition wall in this embodiment can be of hollow cylindrical design and can radially define a drive chamber 11. The drive chamber is delimited in the axial direction, preferably by the bottom 16a or the pump wheel 6 or the wheel disk 36. The rotor 2 or the rotor block 4 is preferably present in the drive chamber 11. Advantageously, an upper cavity is present in the axial direction between the block casing 44 and the pump wheel or the wheel disk 36. A lower cavity is present in the axial direction between the block casing 44 and the bottom 16a. An annular gap 21 is preferably arranged between the side wall 16b and the block casing 44 or the drive section of the shaft 7 or the rotor 2.

[0059] The collar 16c may in particular define part of the wheel chamber 10 and / or part of the collecting passage 28, preferably together with the upper casing part 15a. The collar 16c is preferably present in the upper half of the partition wall. The partition wall flange 16d is preferably offset downwards with respect to the collar 16c.

[0060] The partition wall 16 expediently divides the space inside the casing 15 into a wet area and a dry area. Advantageously, the wet area corresponds to the internal volume formed by the upper casing part 15a and the partition wall 16. Preferably, the dry area corresponds to the internal volume formed by the partition wall 16 and the lower casing part 15b. Preferably, a fluid seal 20a is arranged between the upper casing part 15a and the partition wall 16. In this embodiment, the fluid seal 20a radially surrounds the partition wall 16.

[0061] Expediently, the pump comprises a base plate 18 for controlling the pump operation. The base plate 18 is advantageously present in a dry area of ​​the pump. Preferably, the base plate 18 is in contact with a heat conducting element 38. The heat conducting element 38 can be, for example, a heat conducting paste. Preferably, the heat conducting element 38 is in contact with the outer surface of the partition wall 16 or the bottom part 16a.

[0062] The substrate 18 may have an electrical connection 39 with the stator 1. The substrate 18 may be attached to the stator holder in an area radially opposite the electrical connection 39. Preferably, electrical terminals (not shown) are present in the lower casing part 15b. The substrate 18 may have electronic control elements, for example MOSFETs, which in particular cause a notable portion of the heating of the substrate 18.

[0063] Preferably, the collecting passage 28 or the partition wall 16 or the collar 16c and the rotor 2 or the pump wheel 6 or the wheel disk 36 form an annular gap 37. Preferably, through this annular gap 37, a secondary flow of the fluid branches off from the main flow of the fluid. The secondary flow follows a secondary flow path that is appropriately determined by the pump. The secondary flow is formed due to the pressure difference between the radially outer and the radially inner regions. The secondary flow first flows into the upper cavity 11a and then preferably through the annular gap 21. In the further course of things, the secondary flow then advantageously reaches the lower cavity 11b.

[0064] Particularly preferably, the rotor 2 or rotor body 3 has at least one return guide passage 12, preferably several return guide passages 12, for the secondary flow, which form a fluid connection between the drive chamber 11 and the wheel chamber 10. Expediently, the return guide passages 12 are separated from one another via a separation element 13 of the rotor 2 or rotor body 3. The return guide passage 12 preferably has a lower part 12b, an upper part 12a and an outlet 12c. Advantageously, the cross-sectional area of ​​the lower part 12b is greater than the cross-sectional area of ​​the upper part 12a.

[0065] From the lower cavity 11b, the secondary flow flows upwards through the return guide passage 12 through the rotor 2 or rotor body 3 back into the wheel chamber 10. At the outlet 12c of the return guide passage 12, a lower pressure prevails compared to the pressure in the collecting passage 28. This results in the formation of a secondary flow. The secondary flow removes heat from the stator 1, the base plate 18 and the rotor block 4 and mixes with the main flow in the radially inner region of the wheel chamber 10.

[0066] Preferably, the lower part 12b of the return guide passage 12 at least partially axially overlaps with the rotor block 4. This allows the wall between the rotor block 4 and the lower part of the return guide passage 12 to be relatively thin, so that heat can be well dissipated.

[0067] Preferably, along the lower part 12b of the return guide passages 12, the return guide passages 12 are separated from one another by a separation element 13. The separation element 13 is particularly visible in FIG. 4 and can in particular be configured as a web or a rib. The separation element 13 is suitably connected, on the one hand, to the wall of the rotor body 3 between the rotor block 4 and the return guide passages 12 and, on the other hand, to the wall of the rotor body 3 which directly surrounds the rolling bearing 5. The separation element 13 thus stabilizes the rotor 2 or the shaft 7 of the rotor body 3. At the same time, in particular the separation element 13 causes considerable turbulence in the lower hollow chamber 11b, which leads to losses.

[0068] Very preferably, the rotor 2 has a protrusion 27 which protrudes radially, preferably radially inwards, and which at least partially conceals the entrance of the return guide passage 12 or of the return guide passages 12 in the direction of view towards the underside of the rotor 2. In this embodiment, the protrusion 27 completely conceals the entrance of the return guide passage 12 shown in FIG.

[0069] Preferably, the rotor 2 has a rotor cap 14, which is preferably attached to the lower end of the rotor 2. The rotor cap 14 can be connected to the underside of the rotor body 3, for example by ultrasonic welding. Very particularly preferably, the rotor cap 14 has a projection 27. The projection 27 or the rotor cap 14 shields the separation element 13 from the lower cavity 11b, so that the turbulence is restricted to a much smaller space and the losses due to turbulence in this area are significantly reduced.

[0070] The rolling bearing 5 preferably comprises carbon, in particular graphite. Preferably, the rolling bearing 5 comprises a binder, in particular a polymer. The axle 23 has an effective length AL, which corresponds to the axial length over which the axle 23 exits the axle fixing part 42 or the bottom part 16a and provides a contact surface for the rolling bearing 5. The rolling bearing 5 has an effective rolling bearing length DL, which corresponds to the axial contact length provided between the rolling bearing 5 and the axle 23. The ratio DL / AL corresponds to 0.72 in this embodiment.

[0071] Preferably, a spider 22 is arranged in the flow direction between the suction port 8 and the pump wheel 6. The spider 22 in this embodiment has three legs, which are attached to the inner surface of the suction port 8. The spider 22 preferably has a receiving portion 40 on its underside.

[0072] In this embodiment, the axle retainer 24 is press-fitted into the receiving part 40. The axle retainer preferably comprises a metal, in particular steel or special steel. Advantageously, the axle retainer 24 of the axle 23 allows axial sliding but no radial play. Preferably, the rolling bearing 5 can slide on and rotate axially on the axle 23 but has no radial play relative to the axle 23. The axle retainer has an effective length HL in the axial direction, which corresponds to the contact length with the axle 23. Preferably, the ratio HL / AL corresponds to at least 0.07 or 0.10 or 0.12 or 0.14 or 0.16. Very preferably, the sum DL+HL corresponds to at least 0.5 or 0.6 or 0.7 or 0.8 or 0.9 AL.

[0073] Preferably, the lower casing part 15b has a lower casing flange 31b. Advantageously, the lower casing flange 31b abuts against a holder flange 30 of the stator holder 29. Preferably, the holder flange 30 abuts against the partition flange 16d. Preferably, the holder flange 30 is arranged between the partition flange 16d and the lower casing flange 31b. Preferably, the partition flange 16d is between the upper casing flange 31a and the holder flange 30 or the lower casing flange 31b.

[0074] Very preferably, the upper casing flange 31a, the partition flange 16d, the holder flange 30 and / or the lower casing flange 31b are clamped by a fastening device. The fastening device is preferably a screw connection. Very particularly preferably, the fastening device 41 or the screw device penetrates through the upper casing flange 31a, the partition flange 16d, the holder flange 30 and / or the lower casing flange 31b.

[0075] The pump may be provided with at least one holder seal 20b, preferably two holder seals 20b. In this embodiment, one holder seal 20b is arranged between the stator holder 29 and the lower casing part 15b in the longitudinal section of the pump. One holder seal 20b may be arranged between the stator holder 29 and the partition wall 16.

[0076] 2 shows the bottom 16a of the partition wall 16 in a perspective view, so that the preferred star-shaped arrangement of the ribs 17 in this embodiment can be seen. With their longitudinal extension, the ribs 17 preferably extend from the radially outer region of the bottom 16a towards the radially inner region of the bottom 16a or towards the axle fixing part 42, which is arranged in the radial center of the bottom 16a. The lower end of the axle 23, which is enclosed by the axle fixing part 42 by insert molding, can have an asymmetrical part, for example a groove, which ensures a non-rotatable fixing of the axle 23 in the bottom 16a or in the axle fixing part 42. This stable bottom structure or axle fixing part 42, in conjunction with the equally stable axle holding part 24, allows for an exact positioning of the axle. This in particular ensures a very quiet running of the rotor 2 around the axle 23, which is further assisted in particular by the very long rolling bearing 5. As a result, a very quiet running and low wear are achieved.

[0077] 2 also makes it somewhat easier to see the structure of the rotor cap 14. A further projection of the rotor cap extends axially into the return guide passage 12 or into several return guide passages 12. This further projection has the main purpose of correctly positioning the rotor cap 14 on the rotor 2.

[0078] In Fig. 3, a top view of the rotor body 3 is shown, so that the upper part 12a of the return guide passage 12 and the outlets 12c are visible. Preferably, the outlets are assigned to one vane 19 or one vane passage 43. Preferably, the vanes 19 have plug-in elements on their upper surface, which engage with a wheel cover 25, not shown in Fig. 3. Preferably, the rotor body 3 has engagement elements 26 on its radial inner surface, which are engaged with a rolling bearing 5, not shown in Fig. 3. In this embodiment, the rolling bearing 5 has four axially extending grooves on its outer surface, which are formed complementary to the engagement elements 26 of the rotor body 3 shown in Fig. 3.

[0079] FIG. 4 finally shows a bottom view of the rotor body 3, the rotor cap 14 being omitted for the sake of clarity, as are all other elements except the rotor body 3. The return guide passage 12 and the separation element 13 are thus clearly visible. The separation element 13 is preferably designed in the form of a web. Advantageously, the separation element 13 extends tangentially as viewed in a cross section of the rotor body 3. The separation element 13 rotates clockwise, so that the selected tangential orientation of the separation element 13 is a first measure for reducing turbulence. This measure is further supplemented in particular by the rotor cap 14, which is not shown in FIG. 4.

[0080] 4 it can be clearly seen that the lower part 12b of each return guide passage 12 is preferably significantly larger in terms of the cross-sectional area of ​​the lower part 12b than the upper part 12a of the respective return guide passage 12. The lower part 12b of the return guide passage 12 provides a large volume in order to cool the rotor block 4 as well as possible. Increasing the volume of the lower part 12b of the return guide passage 12 may only be possible by thinning the separating element 13 or the inner wall of the rotor body 3 that abuts against the rolling bearing 5. The upper part of the return guide passage 12a is, on the one hand, very small so that it can be better allocated to the individual vane passages 43. [Explanation of symbols]

[0081] A Rotation axis 1 Stator 2 Rotors 3 Rotor body 4 Rotor Block 5 Rotary bearing 6 Pump Wheel 7 Shaft 8 Intake port 9 Outlet 10 Wheel Chamber 11 Drive chamber 11a Upper hollow chamber 11b Lower cavity 12 Return guide passage 12a Upper part 12b Lower part 12c exit 13 Dividing elements 14 Rotor Cap 15 Casing 15a Upper casing part 15b Lower casing part 16 Partition Wall 16a bottom 16b side wall 16c Color 16d Partition wall flange 17 16 Ribs 18 Substrate 19 6 Feathers 20a Fluid seal 20b Holder seal 21 Annular gap 22 Spider 23 Axle 24 Axle holder 25 2 Wheel Cover 26 3 Engagement Elements 27 2,14 protrusion 28 Gathering aisle 29 Stator holder 30 Holder flange 31a Upper casing flange of 15a 31b Lower casing flange of 15b 32 Magnet 33 Rotor core 34 Stator core 35 Stator Winding 36 Wheel Disc 37 Surrounding Gap 38 Heat Transfer Elements 39 Electrical Connections 40 22 receiving part 41 Mounting device 42 Axle fixing part 43 Feather Passage 44 Block Casing

Claims

1. 1. A pump for driving a fluid, preferably a temperature control medium, in particular for use in a vehicle, in particular for temperature control of a drive battery of an electric vehicle, the pump comprising a stator (1) and a rotor (2), the rotor (2) having a rotor body (3), a rotor block (4) and a rotary bearing (5), the rotor (2) being supported for rotation 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) having a block casing (44) which at least partially encases the rotor block (4), at least a part of the pump intake (8) is arranged in the axial upper half of the pump, and the pump has a discharge (9).

2. 2. The pump according to claim 1, comprising a casing (15) and a partition wall (16) dividing the space inside the casing (15) into a wet area and a dry area, the wet area preferably having a wheel chamber (10) and a drive chamber (11), the pump wheel (6) being present in the wheel chamber (10), and the block casing (44) being preferably arranged in the drive chamber (11).

3. 3. A 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 a main fluid flow path, and the pump is preferably formed such that a secondary fluid flow path branches off from the main fluid flow path and extends from the wheel chamber (10) into the drive chamber (11).

4. 4. The pump according to claim 3, wherein the rotor (2) or rotor body (3) has at least one return guide passage (12), preferably a plurality of return guide passages (12) for the secondary flow, which return guide passages (12) form a fluid connection between the drive chamber (11) and the wheel chamber (10), and which return guide passages (12) are advantageously separated from one another via a separation element (13) of the rotor (2) or rotor body (3).

5. 5. A pump according to any one of claims 1 to 4, wherein the pump comprises a rotationally stationary axle (23), preferably the rotor (2) being rotatably supported on the axle (23).

6. 6. A pump as claimed in claim 1, wherein the rotor (2), when viewed in a longitudinal section of the pump, has a protrusion (27) for reducing turbulence, the protrusion (27) protruding in a radial direction and preferably at least partially obscuring an inlet of a return guide passage (12) in the direction of view looking at the underside of the rotor (2).

7. 7. The pump of claim 1, wherein the rotor (2) has a rotor cap (14), the rotor cap (14) being attached to a lower end of the rotor (2).

8. 8. A pump according to any one of the preceding claims, wherein the rotor body (3) is formed in one piece, preferably integrally.

9. 9. A pump according to any one of claims 1 to 8, wherein the block casing (44) radially surrounds the rotor block (4), at least along an axial portion and at least along a circumferential portion.

10. 10. The pump according to any one of claims 1 to 9, wherein the pump comprises a substrate (18) for controlling pump operation, the substrate (18) being preferably arranged on an outer surface of the partition wall (16).

11. 11. The pump according to claim 4, wherein the return guide passage (12) is present in the rotor (2) or rotor body (3), which preferably completely surrounds the at least one return guide passage (12) in cross section, at least partially in the axial direction.

12. 12. The pump according to claim 5, wherein the rolling bearing (5) has an effective axial rolling bearing length DL and the axle (23) has an effective axle length AL, the ratio DL / AL being 0.4, preferably 0.5, more preferably 0.6 or more.

13. 13. A pump according to any one of claims 5 to 12, wherein the rolling bearing (5) abuts against the axle (23) over its entire circumference, at least along an axial portion, or is grooveless.

14. 14. A pump as claimed in any one of claims 5 to 13, comprising an axle retainer (24), preferably arranged in the upper half, upper third or upper quarter of the axle (23).

15. 15. A pump according to any one of claims 1 to 14, characterized in that a spider (22) is arranged between the suction (8) and the pump wheel (6) in the flow direction, the spider (22) being preferably attached to the casing (15) or to the upper casing part (15a).

16. 16. A pump as claimed in any one of claims 2 to 15, wherein an annular gap (21) extends between a radially outer surface of the drive section (19) of the shaft (7) and an inner surface of the partition wall (16), so that preferably the secondary flow path fluidly connects an upper hollow space (11a) of the drive chamber (11) to a lower hollow space (11b) of the drive chamber (11).

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

18. 18. The pump of any one of claims 2 to 17, wherein the partition (16) comprises a thermoplastic resin, the partition (16) preferably including a conductive additive to improve thermal conductivity.

19. 19. The pump according to any one of claims 1 to 18, wherein the pump comprises a stator holder (29), the stator holder (29) preferably having a holder flange (30), the holder flange (30) preferably abutting a casing flange (31 a, 31 b).

20. The pump comprises a lower casing part (15b), a stator unit, a partition wall unit and an upper casing part (15a), the stator unit comprising the stator (1) and preferably a stator holder (29), the partition wall unit comprising the partition wall (16) and preferably an axle (23), the pump comprising: A lower casing part (15b), Stator unit, Partition wall unit, Rotor (2), An upper casing part (15a), can be assembled in the order of 20. A pump according to any one of claims 2 to 19.

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