Direct cooling of electric machines
The use of helical channels in stators and rotors of electric machines addresses inefficiencies in conventional cooling methods by improving coolant flow turbulence and coverage, resulting in efficient and cost-effective cooling with reduced complexity and increased performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2026-03-05
AI Technical Summary
Existing cooling methods for electric machines, particularly stators and stator end windings, suffer from inefficiencies such as increased pressure drop, reduced performance, and added weight and cost due to conventional cooling jackets and spray nozzles, leading to high temperatures and reduced power density.
Implementing helical channels in the stator and rotor of electric machines to guide coolant flow, which enhances turbulence and coverage area, eliminating the need for additional nozzles and reducing pressure drop, while utilizing intertwined and elliptical cross-sections for efficient cooling.
The helical channel design increases coolant velocity and heat transfer, achieving efficient and reliable cooling of stator and rotor end windings with reduced complexity and cost, thereby enhancing the performance and reliability of electric machines.
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Figure CN2024114774_05032026_PF_FP_ABST
Abstract
Description
Direct Cooling of Electric MachinesTECHNICAL FIELD
[0001] The present disclosure relates toan electric machine comprising a stator and a rotorand, in particular, direct cooling of components of the electric machine.BACKGROUND
[0002] Electric machines, in operation, need some cooling, particularly, cooling of the stators and stator end windings. According to a common approach, a cooling jacket is provided around the stator. The cooling jacket (typically, a copper or aluminum design) is shrunk-fit around the stator circumference such that the large surface area allows the coolant to flow inside the channels of the cooling jacket to carry away heat. However, provision of such a cooling jacket increases both costs and weights and, moreover, reduces efficiency of the electric machine.
[0003] For motors, for example, the stator design may be a slotted one such that it provides a seat for the windings, which are usually arranged in a three-phase configuration. The number of stator slots and the number of magnetic pole pairs are key parameters in determining the mechanical and electrical performance of a motor. A common stator cooling method is air cooling by means of radial ventilation channels axially formed in the stator allowing for simultaneous cooling of the stator and windings. However, air cooling suffers from a non-satisfying efficiency.
[0004] Direct cooling solutions for electric motors exist using oils or dielectric esters in contact with the heat source (for example, stator or rotor laminations and / or copper end windings) . Particularly, direct cooling of end windings of the art incorporates oil spraying or sloshing on the end windings. Such direct cooling solutions are more efficient than indirect cooling by means of cooling jackets. However, there is still a need for increasing the cooling efficiency. Moreover, current direct cooling solutions suffer from the following problems. Multiple channels above the stator slot are required to ensure almost complete spray coverage due to the limited spray angle of current solutions and, thus, the pressure drop across the motor is increased and the lamination mass and overall performance of the electric machine are reduced. Further, at low flow rates, the spray profile is severely compromised resulting in a reduced spray coverage area. This results in high temperatures and hotspots in locations not in contact with the coolant further leading to a lower performance and efficiency. In addition, usually an external spray nozzle has to be provided at the end of each the channel to increase the spray coverage area and direct the flow of the coolant to the end winding. The attachment of an extra component in the form of the spray nozzle increases the overall cost and weight of the motor. It also introduces a potential failure mode to the system further reducing the reliability of the motor. The power density of the motor is also reduced due to the added volume of the attached spray nozzles.SUMMARY
[0005] In view of the above, it is an objective underlying the present application to providetechniques for reliably and efficiently cooling components of an electric machine, particularly, a motor or a generator comprising a stator and a rotor.
[0006] The foregoing and other objectives are achieved by the subject matter of the independent claims. Further implementation forms are apparent from the dependent claims, the description and the figures.
[0007] According to a first aspect, it is provided a stator for an electric machine (for example, a motor or generator) , comprising at least one bundle of (stator) channels (for example, consisting of one of 2 channels, 3 channels, 4 channels and 5 channels) extending entirely through the stator between a first axial end and a second axial end of the stator, wherein each of the channels has a helical longitudinal axis.
[0008] Contrary to the art, the channels formed in the stator for guiding the coolant are of helical structure rather than extending parallel to a longitudinal axis of the stator. The flow of a coolant through the channels is governed by the helical structure of the channels. The helical structure increases the flow velocity and heat transfer coefficient of the coolant due to a relatively turbulent flow profile. Compared to the art, a smaller number of channels is needed to achieve efficient stator cooling during operation of the electric machine and, thus, the pressure drop across the electric machine can be reduced and the lamination mass and overall performance of the electric machine can be increased. At the end portions of the channels the coolant can be sprayed in a wide coverage range to stator end windings for efficiently cooling the same.
[0009] According to an implementation, the stator comprises a stack of stator laminations and the at least one bundle of channels is formed through the stack of stator laminations. By laminating the stator core, eddy currents can be significantly reduced and hysteresis loss can be minimized. Particularly, for a laminated stator core the helical structure of the channels may be realized by offsetting the individual laminations with their respective openings at different sections. The combination of the lamination design and helical channels may result in a particular reliable operation of high efficiency electric machines.
[0010] According to another implementation, the channels of each bundle of channelsformed in the stator are intertwined with each other. Aportion of the coolant that exits one of individual twinned channels can interact with another portion of the coolant that exits another one of the individual twinned channels when the coolant exits the channels at the axial ends of the stator and this interaction can result in a larger spray area and thus, more coverage of end windings of the stator to be cooled by the coolant for a more efficient cooling of the end winding as compared to the art.
[0011] According to another implementation, each of the channels of the at least one bundle of channels has a first end portion and a second end portion and the first end portions of the channels collapse with each other and the second end portions of the channels collapse with each other. Particularly, in combination with the intertwined helical structure of the channels the collapsing channels may result in a spraying effect over a large spray area and, therefore, efficient cooling of end windings of the stator.
[0012] According to another implementation, at least the first end portions and the second end portions of the channels have substantially elliptical cross-sections. According to an example, the channels have substantially elliptical cross-sections all along their extensions. This kind of cross-section may contribute to a favorable spraying effect over a large spray area and, therefore, efficient cooling of end windings of the stator.
[0013] According to another implementation, the first end portions of each of the channels of a bundle of channels are inclined with respect to each other with an angle in the range of 15 ° to 18° for collapsing the first end portions with each other and the second end portions of each of the channels of a bundle of channels are inclined with respect to each other with an angle in the range of 15 ° to 18° for collapsing the second end portions with each other. The angular ranges might be advantageous in terms a large spray area and, therefore, efficient cooling of end windings of the stator.
[0014] Since the channels may be particularly suitable for stator end windings, according to another implementation, the stator according to the first aspect or and implementations thereof, further comprises a first stator end winding at the first axial end of the stator and a second stator end winding at the second axial end of the stator and the first end portions of the channels of each bundle of channels, respectively, provide a first orifice configured and arranged for spraying a coolant transported by the channels towards the first stator end winding and the second end portions of the channels of each bundle of channels, respectively, provide a second orifice configured and arranged for spraying a coolant transported by the channels towards the second stator end winding. At least the thus provided orifices may further increase the spray area and, therefore, efficient cooling of end windings of the stator can be achieved.
[0015] The coolant has to be supplied to the channels in a convenient and reliable manner without increasing complexity of the overall construction. Thus, according to another implementation the stator according to the first aspect or any implementation thereof comprises for each of the bundles of channels an inlet connected to the channels of the respective bundle of channels and configured for supplying a coolant from outside of the stator to the channels and wherein the inlet is orientated substantially perpendicular to a longitudinal axis of the stator extending from the first axial end to the second axial end of the stator. From the inlet the incoming coolant flow can split into opposite directions towards the first and second axial ends of the stator. Thereby, the coolant can be conveniently be transported, for example, from some coolant reservoir located outside of the stator or even the electric machine, to the channels of the stator for cooling purposes.
[0016] According to another implementation, the stator comprises a central space (aperture) configured for accommodating a rotor of the electric machine.
[0017] According to a second aspect, it is provided a rotor for an electric machine (for example, a motor or generator) , comprising at least one bundle of (rotor) channels (for example, consisting of one of 2 channels, 3 channels, 4 channels and 5 channels) extending entirely through the rotor between a first axial end and a second axial end of the rotor, wherein each of the channels has a helical longitudinal axis. These helical channels (similar to the channels provided in the stator according to the first aspect) provide for efficient cooling (of the rotor and stator end windings of a stator in operation with the rotor and / or rotor end windings, if provided) by a turbulent high velocity flow of a coolant therethrough.
[0018] The following implementations may provide the same or similar advantageous technical effect as the implementations of the first aspect. According to an implementation, the rotor comprises a stack of rotor laminations and the at least one bundle of channels is formed through the stack of rotor laminations.
[0019] According to an implementation, the channels of each bundle of channels are intertwined with each other.
[0020] According to an implementation, each of the channels of the at least one bundle of channels has a first end portion and a second end portion and wherein the first end portions of the channels collapse with each other and the second end portions of the channels collapse with each other.
[0021] According to another implementation, at least the first end portions and the second end portions of the channels have substantially elliptical cross-sections.
[0022] According to another implementation, the first end portions of each of the channels of a bundle of channels are inclined with respect to each other with an angle in the range of 22° to 26° for collapsing the first end portions with each other and the second end portions of each of the channels of a bundle of channels are inclined with respect to each other with an angle in the range of 22° to 26° for collapsing the second end portions with each other.
[0023] According to another implementation, the rotor further comprises a first rotor end winding at the first axial end of the rotor and a second rotor end winding at the second axial end of the rotor and the first end portions of the channels of each bundle of channels, respectively, provide a first orifice configured and arranged for spraying a coolant transported by the channels towards the first rotor end winding and the second end portions of the channels of each bundle of channels, respectively, provide a second orifice configured and arranged for spraying a coolant transported by the channels towards the second rotor end winding.
[0024] According to another implementation, the rotor further comprisesa rotor shaft and a supply channel formed axially in the rotor shaft configured for supplying a coolant from outside of the rotor to the channels of the at least one bundle of channels. For each of the bundles of channels an inlet connected to the supply channel and the channels of the respective bundle of channels and the inlet is orientated substantially perpendicular to a longitudinal axis of the rotor extending from the first axial end to the second axial end of the rotor. From the inlet the incoming coolant flow can split into opposite directions into towards the first and second axial ends of the rotor.
[0025] According to a third aspect, it is provided an electric machine, comprising at least one of the stator according to the first aspect or any implementation thereof and the rotor according to the second aspect or any implementation thereof.
[0026] According to an implementation, the electric machine is one of a motor and a generator. Particularly, the motor can be a permanent magnetic synchronous motor for which the helical channel design may be particularly suitable in terms of cooling efficiency.
[0027] According to a fourth aspect, it is provided an electric machine, in particular, a permanent magnetic synchronous motor, comprising a) the stator according to any implementation described above wherein the stator comprises a first stator end winding at the first axial end of the stator and a second stator end winding at the second axial end of the stator and b) the rotor according to any implementation described above wherein the rotor wherein each of the channels of the at least one bundle of channels has a first end portion and a second end portion and wherein the first end portions of the channels collapse with each other and the second end portions of the channels collapse with each other and wherein.
[0028] the first end portions of the channels of the stator and the first end portions of the channels of the rotor are configured and arranged for spraying the coolant in opposite directions towards the first stator end winding and the second end portions of the channels of the stator and the second end portions of the channels of the rotor are configured and arranged for spraying the coolant in opposite directions towards the second stator end winding. By spraying the coolant towards the stator end windings from both top and bottom (from upward and downward, respectively) the stator end windings may be very efficiently cooled during operation of the electric machine.
[0029] Details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims.BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In the following, embodiments of the present disclosure are described in more detail with reference to the attached figures and drawings, in which:
[0031] Figure 1 illustrates a stator for an electric machine comprising bundles of helical channels extending between a first axial end and a second axial end of the stator according to an embodiment.
[0032] Figure 2 shows a cross-sectional view of the stator illustrated in Figure 1.
[0033] Figure 3 illustratescoolant flow within a stator according to an embodiment.
[0034] Figure 4 illustrates an inlet for supplying a coolant to a bundle of helical channels provided in a stator according to an embodiment.
[0035] Figure 5 illustrates a bundle of helical channels provided in a stator or rotor according to embodiments.
[0036] Figure 6 illustrates an orifice formed at end portions of helical channels extending through a stator or rotor according to embodiments.
[0037] Figure 7 illustrates an electric machine comprising a stator with stator end windings and a rotor according to an embodiment.
[0038] Figure 8 shows a cross-sectional view of the electric machine illustrated in Figure 7.
[0039] DETAILED DESCRIPTION OF THE EMBODIMENTS
[0040] Herein, techniques for directcooling of components of an electric machine are provided. The cooling is achieved by means of a coolant directed through helically formed channels provided in a stator and / orhelically formed channels provided in a rotor of the electric machine (for example, a motor or generator) .
[0041] Figure 1 illustrates a stator 100 for an electric machine comprising bundles 10 of helical channels extending entirely through the stator 100 between a first axial end 101 and a second axial end 102 of the stator 100, wherein each of the channels has a helical longitudinal axis. Figure 2 shows a cross-sectional view of the stator 100 illustrated in Figure 1. Here and in the following, the electric machine may be a motor or a generator. Particularly, the electric machine may be a high power density electric motor or a Permanent Magnet Synchronous Motors (PMSM) .
[0042] The channels are configured and arranged for guiding a coolant through the stator for stator cooling and also for cooling of stator end windings provided at the first axial end 101 and second axial end 102 of the stator 100.
[0043] The stator end winding is the part of the winding that protrudes axially from the stator 100. The front and rear-end windings at the first axial end 101 and the second axial end 102 of the stator 100, respectively, are typically surrounded by air and are significant sources of heat and, therefore, require sufficient cooling. The channels penetrate through the stator 100 and at their ends / outlets the coolant is sprayed towards the stator end windings for cooling the same.
[0044] In the example shown in Figure 1, the stator 100 encompasses a central space S configured for accommodating a rotor of the electric machine. The stator may comprise a plurality of laminations (disc-shaped laminated plates made of metal, for example, steel) and, in this case, the channels of the bundles 10 of helical channels are formed through the stator laminations. The helical channels may be formed through the stator laminations by laser cut or chemically etched by offsetting the individual laminations at different sections.
[0045] In particular, the bundles 10 of channels may be uniformly arranged along the circumference direction of the stator 100. As shown in Figures 1 and 2, for example, three bundles 10 of channels are formed through the stator 100.
[0046] The coolant can be supplied to the channels from some coolant reservoir with or without some pumping mechanism. The coolant may be or comprise oil or a di-electric ester, for example. It may high electrically highly insulating properties and may be designed to be stable at relatively high temperatures in the range of 100 ℃ to 300 ℃, for example.
[0047] An exemplary coolant flow through the stator 100 is illustrated in Figure 3. The coolant is supplied to the channels from outside of the stator 100 through an inlet 12 connected to the channels as shown in Figure 4 and it is directed through the channels in opposite directions towards the first axial end 101 and second axial end 102 of the stator 100 for cooling the stator and the stator end windings. The inlet 12 can be arranged substantially perpendicular to the bundles 10 of channels and extends radially through a portion of the stator 100 and penetrates a circumferential surface of the same.
[0048] According the disclosure presented herein, the channels used for guiding the coolant through the stator 100 are of helical structure as it is illustrated in Figure 5. The pitch and helix angle of each helical structure can be designed to increase / decrease the spray angle to control the resulting coverage area for cooling the stator end windings. The helical channel feature can be designed by offsetting the individual laminations of the stator 100 during the stamping or laser cutting process to create a “curve” or bend in the axial length of the stator laminations, for example.
[0049] Figure 5 shows a bundle 10 of channels extending between outlets 14. In the example, shown in Figure 5 the bundle 10 of channels consists of two intertwined channels with helical longitudinal axes. However, a larger number of channels may constitute the bundle 10 of channels. The arrows shown in Figure 5 indicate coolant flow. Coolant is supplied to the bundle 10 of channels through the inlet 12 connected to a guiding portion 13 that is connected to the channels. At the outlets 14, the collapsing end portions of the channels form orifices for spraying the coolant towards the stator end windings over a wide coverage area with a relatively high velocity resulting from the relatively turbulent flow through the intertwined helical channels.
[0050] According to an embodiment, end portions of each of the channels of a bundle 1) of channels are inclined with respect to each other with an angle in the range of 15° to 18° for collapsing the end portions (at both longitudinal ends 101 and 102 of the stator 100) with each other. This angular range might be advantageous with respect to impinging the coolant flow with relatively high velocity causing a characteristic wide-area spray effect. Particularly, the angled channel outlet terminations may remove any need for an attachment of an additional nozzle conventionally used to improve coolant coverage area and velocity. This reduces the overall system cost, weight and potential fault modes.
[0051] Orifices for the bundles 10 of channels at the axial ends 101 and 102 of the stator 100 can be machined as nozzles with substantially elliptical cross-sectional shapes. Figure 6 illustrates a channel outlet design with a substantially elliptical cross-sectional shape of the machined orifice 16 with a cross-sectional contour 16c. Such a cross-sectional shape may be advantageous in terms of a wide coverage area of the coolant sprayed therethrough. Within the machined orifice 16 individual channels of the bundles 10 of channels collapse as illustrated in Figure 6, wherein 10a and 10aa designate channel sections of a channel at different laminations and 10b and 10bb designate channel sections of another channel at different laminations. Collapsing end portions of these channels result in the combined outlet 10o within the machined orifice 16.
[0052] The above-described embodiments refer to one or more bundles of helical channels formed through a stator of an electric machine. However, one or more such bundles of helical channels may also be formed through a rotor of the electric machine. Particularly, at least one bundle of helical channelssimilar to the bundle 10 of helical channels shown in Figure 5 may be formed through the rotor and the outlet configuration illustrated in Figure 6 may also be applied to the rotor.
[0053] Figure 7 illustrates an electric machine 1000 comprising a stator 100, for example, the stator 100 illustrated in Figures 1 to 4, and a rotor 200 as well as a rotor shaft 28 facilitating rotation of the rotor 200. Figure 8 shows a cross-sectional view of the electric machine 1000 illustrated in Figure 7. According to an embodiment, the rotor 200 for the electric machine 1000 comprises at least one bundle 20 of channels extending entirely through the rotor 200 between a first axial end 201 and a second axial end 202 of the rotor 200, wherein each of the channels has a helical longitudinal axis.
[0054] According to the example shown in Figure 7, a bundle 20 of channels consists of two intertwined helical channels. However, a larger number of channels may constitute the bundle 10 of channels. At the outlets at the axial ends 201 and 202 of the rotor 200 the channels may spray coolant to rotor end windings (if provided) and / or stator end windings 19 of the stator 100. End portions of each of the channels of a bundle 20 of channels may be inclined with respect to each other with an angle in the range of 22° to 26° for collapsing the end portions with each other. A collapse angle in the range of 22° to 26°, for example, a collapse angle of 24° may ensure an angled spray biased towards the underside of the stator end windings 19.
[0055] The arrows in Figure 7 indicate the coolant flow pattern and the arrows in Figure 8 indicate the radial coolant flow. Coolant can be supplied from outside of the rotor 200 to the channels of the at least one bundle 20 of channels through a supply channel 21 formed axially in the rotor shaft 28. For each of the bundles 20 of channels an inlet 22 is connected to the supply channel 21 and a guiding portion 23 connecting to the channels of the respective bundle of channels wherein the inlet 22 is orientated substantially perpendicular to a longitudinal axis of the rotor200 extending from the first axial end 201 to the second axial end 202 of the rotor 200. Thus, the coolant is guided in a radial direction and the coolant flow splits in opposite directions towards the first axial end 201 and second axial end 202 of the rotor 200 for cooling the stator 200 and the stator end windings 19 (and / or rotor end windings if present) .
[0056] The one or more bundles 10 of channels formed in the stator 100 and the one or more bundles 20 of channels formed in the rotor 200 may be arranged such that the coolant is sprayed onto the stator end windings 19 from opposite directions (downward spraying by the bundle (s) 10 of channels formed in the stator 100 and upward spraying by the bundle (s) 20 of channels formed in the rotor 200) in order to achieve a very efficient cooling of the stator end windings 19 from top and bottom.
[0057] All previously discussed embodiments are not intended as limitations but serve as examples illustrating features and advantages of the invention. It is to be understood that some or all of the above-described features can also be combined in different ways.
Claims
1.Stator (100) for an electric machine (1000) , comprisingat least one bundle (10) of channels extending entirely through the stator (100) between a first axial end (101) and a second axial end (102) of the stator (100) , wherein each of the channels has a helical longitudinal axis.2.The stator (100) according to claim 1, wherein the stator (100) comprises a stack of stator laminations and the at least one bundle (10) of channels is formed through the stack of stator laminations.3.The stator (100) according to any of the preceding claims, wherein the channels of each bundle (10) are intertwined with each other.4.The stator (100) according to any of the preceding claims, wherein each of the channels of the at least one bundle (10) of channels has a first end portion and a second end portion and wherein the first end portions of the channels collapse with each other and the second end portions of the channels collapse with each other.5.The stator (100) according to claim 4, wherein at least the first end portions and the second end portions of the channels have substantiallyelliptical cross-sections.6.The stator (100) according to claim 4 or 5, wherein the first end portions of each of the channels of a bundle (10) of channels are inclined with respect to each other with an angle in the range of 15° to 18° for collapsing the first end portions with each other and the second end portions of each of the channels of a bundle of channels are inclined with respect to each other with an angle in the range of 15 ° to 18° for collapsing the second end portions with each other.7.The stator (100) according to any of the claims 4 to 6, further comprising a first stator end winding (19) at the first axial end (101) of the stator (100) and a second stator end winding (19) at the second axial end (102) of the stator (100) ;and whereinthe first end portions of the channels of each bundle (10) of channels, respectively, provide a first orifice configured and arranged for spraying a coolant transported by the channels towards the first stator end winding (19) and the second end portions of the channels of each bundle (10) of channels, respectively, provide a second orifice configured and arranged for spraying a coolant transported by the channels towards the second stator end winding (19) .8.The stator (100) according to any of the preceding claims, further comprising for each of the bundles (10) of channels an inlet connected to the channels of the respective bundle (10) of channels and configured for supplying a coolant from outside of the stator (100) to the channels and wherein the inlet is orientated substantially perpendicular to a longitudinal axis of the stator (100) extending from the first axial end to the second axial end of the stator (100) .9.The stator (100) according to any of the preceding claims, wherein the at least one bundle (10) of channels consists of one of 2 channels, 3 channels, 4 channels and 5 channels.10.The stator (100) according to any of the preceding claims, wherein the stator (100) encompasses a central space configured for accommodating a rotor of the electric machine (1000) .11.Rotor (200) for an electric machine (1000) , comprisingat least one bundle (20) of channels extending entirely through the rotor (200) between a first axial end (201) and a second axial end (202) of the rotor (200) , wherein each of the channels has a helical longitudinal axis.12.The rotor (200) according to claim 11, wherein the rotor (200) comprises a stack of rotor laminations and the at least one bundle (20) of channels is formed through the stack of rotor laminations.13.The rotor (200) according to claim 11 or 12, wherein the channels of each bundle (10) of channels are intertwined with each other.14.The rotor (200) according to any of the claims 11 to 13, wherein each of the channels of the at least one bundle (20) of channels has a first end portion and a second end portion and wherein the first end portions of the channels collapse with each other and the second end portions of the channels collapse with each other.15.The rotor (200) according to claim 14, wherein at least the first end portions and the second end portions of the channels have substantiallyelliptical cross-sections.16.The rotor (200) according to claim 14 or 15, wherein the first end portions of each of the channels of a bundle (20) of channels are inclined with respect to each other with an angle in the range of 22° to 26° for collapsing the first end portions with each other and the second end portions of each of the channels of a bundle (20) of channels are inclined with respect to each other with an angle in the range of 22° to 26° for collapsing the second end portions with each other.17.The rotor (200) according to any of the claims 14 to 16, further comprising a first rotor end winding at the first axial end (201) of the rotor (200) and a second rotor end winding at the second axial end (202) of the rotor (200) ;and whereinthe first end portions of the channels of each bundle (20) of channels, respectively, provide a first orifice configured and arranged for spraying a coolant transported by the channels towards the first rotor end winding and the second end portions of the channels of each bundle (20) of channels, respectively, provide a second orifice configured and arranged for spraying a coolant transported by the channels towards the second rotor end winding.18.The rotor (200) according to any of the claims 14 to 17, further comprisinga rotor shaft (28) ;a supply channel (21) formed axially in the rotor shaft (28) configured for supplying a coolant from outside of the rotor (200) to the channels of the at least one bundle (20) of channels; andfor each of the bundles (20) of channels an inlet (22) connected to the supply channel (21) and the channels of the respective bundle of channels and wherein the inlet (22) is orientated substantially perpendicular to a longitudinal axis of the rotor (200) extending from the first axial end (201) to the second axial end (202) of the rotor (200) .19.The rotor (200) according to any of the claims 11 to 18, wherein the at least one bundle (20) of channels consists of one of 2 channels, 3 channels, 4 channels and 5 channels.20.Electric machine (1000) , comprising at least one of the stator (100) according to any of the claims 1 to 10 and the rotor (200) according to any of the claims 11 to 19.21.The electric machine (1000) according to claim 20, wherein the electric machine (1000) is one of a motor and a generator.22.The electric machine (1000) according to claim 21, wherein the electric machine (1000) is a permanent magnetic synchronous motor.23.Permanent magnetic synchronous motor, comprisingthe stator (100) according to claim 7 or according to any of the claims 8 to 10 in combination with claim 7; andthe rotor (200) according to any of the claims 14 to 16 or according to claim 18 in combination with any of the claims 14 to 16, whereinthe first end portions of the channels of the stator (100) and the first end portions of the channels of the rotor (200) are configured and arranged for spraying the coolant in opposite directions towards the first stator end winding (19) and the second end portions of the channels of the stator (100) and the second end portions of the channels of the rotor (200) are configured and arranged for spraying the coolant in opposite directions towards the second stator end winding (19) .
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