Rotor core as a pump for a cooling medium

Abstract

A rotor lamination stack (12) for a rotor (6) of an electrical machine (2) contains a cooling channel (20) for guiding a cooling medium (24) in an axial conveying direction (26) through the rotor lamination stack (12), which has axially stacked laminations (18), wherein each of the laminations (18) has a cooling channel opening (34) as part of the cooling channel (20), wherein cooling channel openings (34) of two adjacent laminations (18) overlap in an overlap region (36), and the respective cooling channel (20) is formed by arranging the cooling channel openings (34) and overlap regions (36) in a row along a conveying line (22), wherein the conveying line (22) is a helical line which, viewed in the conveying direction (26), is wound around the axis of rotation (10) counter to the direction of rotation (8). A rotor arrangement (90) with the rotor core (12) contains a guide means (92) for the cooling medium (24) which, during operation (B), is arranged to guide the cooling medium (24) with respect to the rotor core (12).A cooling arrangement (120) for the electrical machine (2) with the rotor core (12) or the rotor arrangement (90) contains a reservoir (100) for cooling medium (24), and a suction line for supplying cooling medium (24) from the reservoir (100) to the rotor core (12).

Description

The invention relates to an electric machine having a rotor which in turn contains a laminated rotor core. The rotor and thus its laminated rotor core rotate relative to the base body and stator in a rotational direction about an axis of rotation during operation of the machine. The direction of rotation is thus the direction of rotation of the rotor laminated core during operation about the axis of rotation. In particular, the machine also contains a base body and in particular also a stator which rests with respect to the base body of the machine. The rotor and the rotor laminated core then rotate with respect to the base body and, if appropriate, the stator.The invention relates to such machines which are to be cooled during operation by means of a cooling medium, for example oil.DE 199 05 540 A1 discloses an electric machine having an external stator and an internal, rotatably mounted rotor which has a laminated rotor core and a rotor shaft connected to the laminated rotor core in a rotationally fixed manner. The rotor is hollow and a cooling medium can be passed through in the region between the rotor laminated core and the rotor shaft.The object of the present invention is to propose improvements with respect to the cooling of an electric machine.The object is achieved by a laminated rotor core according to patent claim 1. preferred or advantageous embodiments of the invention and other categories of invention are evident from the further claims, the following description and the appended figures.The rotor laminated core is one for a rotor of an electric machine. The rotor laminated core and, with the latter, the rotor rotate during operation of the electric machine and thus of the laminated core in a rotational direction about an axis of rotation of the electric machine or of the rotor or of the laminated core.The rotor laminated core contains at least one cooling channel. Each of the cooling channels extends along a conveying line through the laminated rotor core. In this case, it extends between two end openings as respective ends of the cooling channel. One of the end openings is an inlet opening, the other an outlet opening. The conveying line and the cooling channel extending along it run within the laminated rotor core, and thus outside a shaft of the rotor or shaft receptacle of the laminated rotor core, as explained further below.The cooling channel is configured to guide a cooling medium. The guidance is effected in an axial conveying direction through the laminated core. The cooling medium is thus guided through the laminated core in a direction which points from one end face / end face of the laminated rotor core to the other end face of the laminated rotor core. The conveying direction describes the basic directed orientation of the conveying, i.e. from which the conveying takes place to which end side. The conveying direction is an axial direction and is parallel to or in the axial direction of the axis of rotation. It can consequently have only one direction (in the non-directional axial direction) or the opposite direction.The laminated rotor core contains a plurality of axially stacked laminations in a manner customary in the art. The sheets extend flat in a transverse plane to the axis of rotation.Each of the sheets has at least one cooling channel opening. At least one of the cooling channel openings of each sheet forms a part of a respective cooling channel. Possible further, i.e. second, third and further cooling channel openings in a respective sheet metal can be part of one or more further cooling channels. However, this does not have to be: further cooling channel openings can also be unused, i.e. they cannot be part of a cooling channel. The cooling channel opening is an aperture which completely penetrates the sheet metal between its flat sides.Between cooling channel openings and cooling channels there is in particular a one-to-one assignment in each case. That is to say, a corresponding cooling channel opening is assigned exactly to one cooling channel and a cooling channel is also assigned exactly to one of the cooling channel openings of a metal sheet. Each cooling channel is formed by a row-tending in the axial direction-of the cooling channel openings of the metal sheets.In the rotor laminated core, the following applies to two adjacent laminations: at least one of the cooling channel openings of one and the other lamination overlap in a respective overlap region. The overlap region is a surface in a transverse plane to the axis of rotation at the boundary surface between the two sheets. The overlap region is at least part of the respective cross section of the corresponding cooling channel openings on both sides of the boundary surface. The overlap region thus corresponds to the cooling channel cross section at the corresponding boundary surface between the two sheets.The following applies to the two sheets closing the rotor laminated core on the end: here, one cooling duct opening forms an inlet opening for cooling medium into the rotor laminated core, the other forms an outlet opening for cooling medium out of the rotor laminated core or into the cooling duct or out of the latter.The respective cooling channel is formed by a row of the or its associated cooling channel openings along the conveying line. The alignment takes place on the basis of or by utilizing the overlap regions creating a passage between two sheets. In other words, a row of cooling channel openings is thus carried out continuously through all the metal sheets. The alignment tends to take place in the axial direction in order to pass from one end side to the other of the laminated rotor core. This means that the alignment has an axial directional component. "Based on the overlap regions" is to be understood in this case such that two adjacent sheets are rotated or arranged with their cooling duct openings relative to one another in such a way that an overlap region is formed between them and thus a part of the cooling duct is formed from the two connected cooling duct openings."Along the conveying line" also includes the following: The conveying line can run "straight", e.g. as a helix, without buckling. The cooling channel itself can also run in a staircase shape, i.e. does not have to follow exactly the conveying line in a straight line, but can also approximate it (in the manner of a digital adaptation) in a staircase shape or follow it in such a way.However, the conveying line also has a directional component transversely to the axial direction: the conveying line is a helical line. Viewed in the conveying direction, this is wound counter to the rotational direction about the rotational axis. The term "helix" is to be understood broadly here. In particular, it is a helical line in the actual sense, i.e. a helix which has a constant radius with respect to the axis of rotation. Optionally, however, any desired variable radius of the conveying line is also conceivable along the axial direction, which can lead to a spatial spiral, for example. Mixed forms of corresponding lines are also conceivable. Only the relevant inclination of the conveying line with respect to the axial direction counter to the direction of rotation is decisive in order to achieve the pumping effect for cooling medium in the cooling channel explained below. The winding of the helical line about the axis of rotation can be limited here to a part of a winding (less than 360°) on the axial length of the laminated rotor core, but can also comprise one or more than one winding.In other words, the sheets or cooling duct openings are therefore offset / rotated with respect to the axis of rotation in the circumferential direction by a respective inclination angle in such a way that the cooling duct is formed along the described helical line / conveying line with winding counter to the direction of rotation.According to the invention, the walls of the cooling channel lying counter to the direction of rotation / direction of rotation of the rotor are therefore designed or inclined during operation such as side surfaces of blades of a turbine or of a turbocharger. This applies only to turbochargers of axial construction. These are generally more easily installed in large engines. Most vehicle turbochargers are radial compressors or radial turbines. However, the same principle is used. The cooling channel thus has the same effect on the medium in the cooling channel of cooling medium (optionally a mixture of fluid, e.g. oil and gas, e.g. air) as a turbine or turbocharger, an axial compressor, etc. As a result of the rotation of the laminated rotor core during operation, a pumping effect is thus exerted on medium in the cooling channel or the cooling medium. This is transported through the laminated core in the conveying direction and in the process sucked in from outside the laminated core at the inlet opening and ejected or pushed out of the laminated core at the outlet opening.Because of the pumping effect on the cooling medium, an additional or external pump for delivering the cooling medium in the engine can be dispensed with. The laminated rotor core or the rotor itself becomes the pump for the cooling medium solely on account of its intrinsic rotation during operation.In particular, the laminated rotor core contains a central shaft receptacle extending along the axis of rotation for the rotationally fixed reception of a rotor shaft of the rotor in the laminated core. Each of the sheets then includes a central shaft receiving aperture as part of the shaft receiving aperture.In particular, the rotor also contains a plurality of rotor poles distributed in the circumferential direction, which each have at least one magnet receptacle for receiving at least one magnet (e.g. permanent magnet) generating the magnetic pole. However, this should not be understood as a limitation to permanently excited machines. The principle can also be used without problems for asynchronous machines and is conceivable for externally excited synchronous machines. For this purpose, in particular a plurality of magnet receiving openings distributed in the circumferential direction are provided for forming the magnet receivers in the metal sheets. The magnet arrangement can be designed as desired independently of the helical line profile of the cooling channels, for example linearly interlaced or V-interlaced in a manner customary in the art. The reason for this is the utilization of the reluctance effect. This is therefore carried out in such a way in synchronous machines with an increased reluctance component.In a preferred embodiment, at least one of the cooling channel openings is at least part of a flow blocking recess in the metal sheet. The flow blocking recess is then also at least in this respect an opening of the metal sheet. This embodiment is of particular interest in connection with the above-mentioned magnet pole-generating magnets, since air is often assigned to them as a flux barrier. The air is then contained in corresponding recesses, flow blocking recess ("flow blocking"). By using it for the coolant channel, the flux barrier recess is assigned a dual function, namely on the one hand that of the magnetic flux barrier and on the other hand that of the functionality as a coolant channel. The flow blocking recess is designed primarily for this purpose in the design of the sheet metal as such; only now is the flow blocking recess that is already present used as a cooling channel opening.In a preferred embodiment, at least one of the cooling duct openings is an aperture in the sheet metal serving specifically (in particular, but not necessarily exclusively) for forming the cooling duct. In particular, such a cooling channel opening is therefore not introduced into a metal sheet or designed there in the sheet metal design in order to block the flow there, but only for the purpose of placing the cooling channel here.In a preferred embodiment, at least two adjacent ones of the metal sheets each have at least two cooling channel openings offset relative to one another in the circumferential direction at the same radial distance from the axis of rotation. In addition, two non-corresponding cooling channel openings then have the overlapping region with one another. "Non-corresponding" cooling channel openings are those which do not correspond in two metal sheets having identical openings. Rather, in the case of two sheets with identical cooling channel openings in one sheet, the one, in the other sheet not the same but a different cooling channel opening are used in order to be brought to overlap. This applies in particular to two identical sheets, in which the cooling channel openings are therefore also identical. It is thus possible, by using identical metal sheets, to establish also at least two differently oriented cooling channels. The geometry or arrangement of the cooling channel openings in the metal sheets and the rotational offset between two respective metal sheets are then matched or matched to one another.In a preferred embodiment, the rotor laminated core contains at least two laminated sub-cores which are arranged axially one after the other. Each detailed laminated core contains a plurality of the axially stacked sheets. The invention is therefore also suitable for rotor laminated cores which are constructed from laminated sub-cores.In a preferred variant of this embodiment, within at least one of the partial laminated cores, the cooling duct openings are aligned in the axial direction, i.e. parallel to the axis of rotation. In the case of identical cooling channel openings, the overlapping region is therefore also identical to the cross section of the cooling channel openings. The respective section of the cooling channel within the partial laminated core likewise runs in the axial direction, and all cooling channel openings are completely involved in the cooling channel. Thus, optimum utilization of the cooling channel openings as a section of the cooling channel in the partial laminated core takes place.If this is the case with a plurality of partial laminated cores arranged one after the other, a "staircase shape" of the entire cooling channel is obtained, that is to say cooling channel sections running axially in sections but offset with respect to one another in the circumferential direction. Viewed in the conveying direction, the subsequent partial laminated core is then always rotated with respect to the cooling channel counter to the direction of rotation with respect to the preceding partial laminated core in order to form or approximate the helical line in a staircase-like manner. The screw line can nevertheless be "straight", i.e. have no staircase shape.In a preferred variant of this embodiment, all the sheets of at least one of the partial laminated cores are identical. A part of the laminated core can thus be produced particularly easily.In a preferred embodiment, all the laminations of the rotor laminated core are identical. The entire rotor laminated core can thus be produced particularly easily.In a preferred embodiment, the rotor laminated core has at least two cooling channels. At least two of the cooling channels have opposite conveying directions (i.e. both possible orientations of the axial direction of the axis of rotation). Opposite conveying directions then also means that the associated conveying lines are wound in the opposite direction about the axis of rotation. Thus, two cooling channels are produced in the rotor laminated core, which transport cooling medium in opposite directions with respect to the axial direction in one and the same rotational direction of the laminated core. In other words, when the rotor laminated core rotates, cooling medium is conveyed through the rotor laminated core in the opposite direction in each case by both cooling ducts. Coolant conveyed during operation is thus available on both axial / end ends / end sides of the laminated rotor core (at the outlet openings of the cooling channels there).The object of the invention is also achieved by a rotor arrangement according to patent claim 10. This is configured to guide the cooling medium in relation to the rotor laminated core during operation. This "guide" is to be understood as meaning both a supply of cooling medium to the laminated rotor core and a discharge of cooling medium from the laminated rotor core. This is also to be understood as a complication or prevention of flow of cooling medium into the laminated rotor core (cooling channel, inlet opening) or out of the laminated rotor core (outlet opening). In the rotor arrangement, a controlled guidance of the cooling medium with respect to the rotor laminated core thus takes place.In a preferred embodiment, at least one of the guide means is a suction pickup. The suction pick-up / pick-up does not rotate with the laminated rotor core during operation. Rather, it is configured to be stationary with respect to the aforementioned base body of the electric machine (or / also, for example, a stator). The guide means then comprises a line section. The line section has a line end. The line end faces one of the end sides of the rotor laminated core. The line end in the suction collector is configured to feed cooling medium to an inlet opening of one of the cooling channels in the laminated rotor core out of the line section. In the suction receiver, cooling medium is taken up from an outlet opening of one of the cooling channels in the laminated rotor core and fed to the line section. Inlet and outlet openings are collectively referred to as end openings. When reference is made here to "cooling channels" in the majority, this always also means a single cooling channel, if only one is present.In particular, guide means or line section and in particular the line end are arranged in a contact-free manner with respect to the rotor laminated core in order to operate without friction. In particular, a gap / air gap is located between the line end and the end face of the laminated rotor core. The opening area of the pickup (line end) need not be equal to the opening area of the rotor channel. Thus, the feed (line end) can be designed larger than the channel (inlet / outlet opening, cooling channel opening) itself. In other words: different opening cross sections or opening areas can be present here. The shape of the surface of the inlet / outlet (line end) does not necessarily have to be the same as the mouth of the cooling channel (inlet / outlet opening) in the end face of the rotor. The gap is dimensioned such that as much cooling medium as possible does not emerge there, but rather its almost complete transport takes place between the cooling channel and the line end or line section.Thanks to such a guide means, cooling medium can be supplied to the cooling channel or discharged therefrom in a precisely targeted manner and carried on in the respective line section.In a preferred variant of this embodiment, the line end is limited to a circumferential region of less than 360°, in particular less than 180°, in particular less than 90°, in particular less than 45°, about the axis of rotation. In other words, a supply or discharge of cooling medium with respect to the rotor laminated core therefore takes place only at a specific circumferential position / circumferential region. This is particularly uncomplicated to implement. A supply / discharge of cooling medium with respect to the rotor laminated core takes place there in a pulsed / sectional manner.In an alternative to this, the line end extends over the entire circumference around the axis of rotation, in particular in a limited radial region. In this way, cooling medium is supplied to or discharged from all cooling channels (inlet / outlet openings) situated in this radial region over the entire circumference about the axis of rotation. This results in a continuous uninterrupted coolant flow or is made possible. However, this construction is more complicated.In particular, it should be noted that the invention mainly brings about the conveyance of oil-air mixture. The end face of the rotor does not have to be 100% sealed against the pick-up elements (suction pick-up elements / pick-up elements). A 100% seal would involve considerable effort, if practically possible at all. Therefore, some air is always drawn in through the gap between the rotor and the suction pick-up / pick-up. This leads to the advantage that the droplets can be cooled well and thus considerably fewer pumping losses are produced than if an attempt were made to suck pure (liquid) oil with the rotor.Here, by balancing the advantages and disadvantages of both alternatives, the more favorable variant can be selected for a specific application or a specific rotor laminated core.In a preferred embodiment, at least one of the guide means is a closure element which does not rotate with the laminated rotor core during operation, see analogously above the suction pick-up / pick-up. It should be mentioned again here that there must always be one suction pick-up, but not always one suction pick-up. The closure element has a closure surface which faces a respective end face of the laminated rotor core. The closure element is configured to prevent cooling medium from flowing into or out of the end openings of the cooling channels (inlet or outlet opening) on the closure surface. In particular when closing upstream end openings, it is thus possible to prevent or reduce an escape of cooling medium from the laminated rotor core at a specific circumferential position about the axis of rotation (fixed with respect to a stator) if, for example, a coolant escape is undesirable or unfavourable in particular in relatively large quantities there or coolant is intended to escape at another circumferential position.The object of the invention is also achieved by a cooling arrangement according to claim 14 for an electric machine. This contains the laminated rotor core according to the invention or the rotor arrangement according to the invention as well as a reservoir for cooling medium and a suction line. The suction line is configured to supply cooling medium from the reservoir to the laminated rotor core. The suction line is in particular connected or forms an extension of the line section of a suction pickup.Optionally, a return line is also provided, which is configured to return cooling medium, which has exited the rotor laminated core, into the reservoir. The return line in the form of the suction collector can also transfer the cooling medium (oil / air mixture) to another location such as a bearing, a gearwheel, a stator cooling, etc. If necessary, a collecting region such as another "reservoir", for example a bunker for separating air bubbles, can also be provided. Downstream lubrication / cooling points can thus be supplied with pure oil, i.e. without an air fraction. By the above-mentioned collecting region is meant a separate "reservoir", not the one mentioned above, from which suction is drawn.Thus, a targeted guidance of coolant from the reservoir toward the laminated rotor core takes place, optionally also a targeted return of coolant into the reservoir. In other words, a cooling circuit can thus be set up which stores cooling medium in the reservoir, from which it is suctioned or conveyed thanks to the pumping capacity of the laminated rotor core and is in particular returned to the reservoir again. In particular, an oil cooler (see below) can also be provided, through which the oil passes before it is fed back to the reservoir (oil sump).In a preferred embodiment, the cooling arrangement also contains a suction filter which is arranged between the reservoir and the laminated rotor core upstream of the laminated rotor core. This is in particular a coarse filter. This prevents dirt particles, etc., from getting to the laminated rotor core with the cooling medium.Alternatively or additionally, the cooling arrangement contains a cooler for cooling the cooling medium.Alternatively or additionally, the cooling arrangement contains a pressure filter which is arranged between the laminated rotor core and the reservoir downstream of the laminated rotor core. This can be, in particular, a fine filter. This too leads to a further cleaning of the cooling medium. The pressure filter is supplied in particular from the extended line section of a suction pick-up, which then provides the cooling medium under pressure to the pressure filter.Alternatively or additionally, the cooling arrangement contains an ejector pump which is operated during operation by cooling medium which exits from the laminated rotor core with pressure or enters it, i.e. is sucked in. In other words, the pumping action of the laminated rotor core is used to cause pressure in or a flow of the cooling medium and to operate the suction jet pump with the pressure-affected or flowing cooling medium in order to bring about further transport of cooling medium in and optionally also outside the cooling arrangement. A suction jet pump would therefore also be mountable on the suction side.Alternatively or additionally, the cooling arrangement contains a cooling medium bunker which is configured to be filled during operation with cooling medium which is pumped / filled there from the laminated rotor core. The cooling medium bunker can furthermore be emptied of cooling medium by gravity or cooling medium flows out of the cooling medium bunker solely by gravity when the latter is in an intended installation position / spatial orientation. Thus, independently of the operation of the laminated rotor core and its pumping capacity, a flow of cooling medium following the operation can be provided solely by gravity. This is at least until all the coolant in question has exited the coolant bunker by gravity. Corresponding cooling medium can, for example, still cool or lubricate further components of the motor or the rotor laminated core itself by means of gravity operation during the following of an operation of the rotor laminated core, that is to say after the latter has come to a standstill. In other words, a gravity-driven cooling medium supply results which tracks operation. In particular, the cooling medium bunker is an oil bunker when oil is used as cooling medium. In particular, air can thus be separated out of the oil / air mixture in the bunker, so that only (liquid) oil can emerge or emerge. For this purpose, the bunker may require a venting opening, optionally even with overflow.The invention is based on the following findings, observations or considerations and still has the following preferred embodiments. These embodiments are also sometimes referred to simply as "the invention". The embodiments can also contain parts or combinations of the above-mentioned embodiments or correspond to these and / or optionally also include embodiments not mentioned up to now.According to the invention, a rotor design for replacing a coolant pump in wet-running electric motors (electric machine) results. The invention includes one possibility of representing a prime mover (electric machine) without a separate coolant pump.The invention starts from the following starting position known from practice: In the vehicle sector, liquid-cooled electric drive motors (electric machine) are mainly used. To ensure the service life and the continuous power, the cooling must dissipate the resulting power loss. Coolant pumps are used for transporting the cooling medium. These are generally separate components and are driven by their own electric motor.The invention is based on the following findings and the following ideas: To represent continuous power, electric drive systems (electric machine) require coolant pumps. The coolant pumps are cost-limiting, reduce low voltage efficiency, and increase the overall weight of the propulsion system. However, since the vehicle drive itself has rotating parts, the pumping power can also be represented thereby. It is therefore desirable to provide a possibility for a drive machine without a separate coolant pump.Many types of pump are known from practice. Some work with chambers that change their volume, others place the pump power via the mass inertia of the pump medium (for example. Turbocharger). With the exception of reciprocating piston or diaphragm pumps, the pumping power is usually provided by a rotating component. However, since the electric drive already has a rotating rotor, this can assume the function of the pump in addition to its actual primary function.The invention uses the mass inertia of the cooling medium and also the mass inertia of the surrounding air. The behavior is similar to a turbine or a turbocharger; technically, the rotor represents a so-called axial compressor. The invention is based on the concept of integrating the functionality in such a way that no additional outlay and no additional components arise.The invention uses the following physical principle: If a general turbine known from practice is viewed in plan view, it rotates in a rotational direction about the rotational axis. Air or liquid particles within blades inclined to the axis of rotation are guided along the latter. The turbine transports the surrounding medium obliquely in a specific direction with a directional component along the axis of rotation.The following applies now to a rotor of an electric machine with a V-shaped interleaved rotor laminated core made of laminated sub-cores: It becomes clear from the arrangement of magnets in the rotor that the rotor is divided into a plurality of segments (laminated sub-cores). The rotation of the segments relative to one another is similar to the section through an axial compressor. The invention is based on the idea: By means of an intelligent arrangement of openings, channels can be created which transport the cooling medium from one side to the other.The invention is based on the following ideas with respect to a design of a rotor or rotor laminated core: the idea comprises several possibilities, such as the sheet metal section (design of a sheet metal of the laminated core, starting from a design known from practice without a pumping effect) can be adapted in order to generate a pumping effect.Variants for channel formation generally represent possibilities for representing a channel for coolant transport. This is done by means of possibilities for adapting the 2D sheet metal cut. Openings (cooling channel openings) of a segment (sheet metal, partial laminated core) meet the openings of the following segment in the overlap zone (boundary between two sheets / partial laminated cores, overlap region). This rotation relative to one another represents an axial compressor over the length of the rotor.A design in the case of a mirrored direction of rotation for long rotors (V-shaped entanglement of the magnet arrangement) takes into account the fact that long rotors are usually rotated in a mirrored manner. In this case, (as viewed in the axial direction of the axis of rotation) the two innermost segments are neutral to one another. In one (axial) direction, it is rotated with a positive angle and in the other direction it is also rotated with a positive angle. For example, a rotor with six partial laminated cores (segments) applies. The segments 3 and 4 are neutral to each other, while the segments 1 and 2 are rotated in a mirror-image manner with respect to the segments 5 and 6.The following concepts are possible in channel formation:• Use of existing flux barriers (flux barriers, cavities in the laminated rotor core) in the case of a one-sided pumping direction• Use of an additional opening (in addition to the flow barriers) in the case of a one-sided pumping direction• Use of a plurality of (in particular) three additional openings in the case of pumping directions on both sidesIn the case of the above-mentioned mirrored direction of rotation in the case of long rotors, the following applies: in the case of a rotor having, for example, six partial laminated cores with mirrored rotation: the segments 1 to 3 are arranged in this case in a mirrored manner with respect to the segments 4 to 6. Solely from the V-shaped arrangement of the magnets, a simple channel formation is not possible here. In order to nevertheless represent a pumping performance in an axial direction, the principle of the plurality of, in particular three, additional openings is used in modified form: it was described above how a pumping action in two directions can be represented with three openings in the case of unidirectional rotation. In order to create this property, the sheet metal cuts of the segments 1 to 3 are to be chosen differently from the sheet metal cuts of the segments 4 to 6. However, the pump openings are located here not on different radii as in the solution with three openings at the top, but on the same radius. However, one of the three openings is provided in segments 1 to 3, and the other two of the three openings are provided in segments 4-6 (offset relative to one another in the circumferential direction). Openings that do not correspond in each case are overlapped here.A further aspect is the steering of the cooling medium: here, several possibilities are conceivable for how the cooling medium can be supplied to the rotor. A distinction is made here between the following two methods.• Suction of the cooling medium is shown at the suction collector. The cooling medium sucked in through the rotor is atomized and fluidized after it leaves the rotor.• At the pump pickup, the cooling medium is actively and selectively passed on. The cooling medium is thereby drawn in, transported through the rotor and subsequently (at one line end) guided into a channel (line section), through which it can be guided in a targeted manner at cooling or lubrication points.In addition, closure plates (closure elements) can be attached to the outflow side (of the rotor laminated core, outlet opening of the cooling channel). Since the position of the outflowing coolant is dependent on the rotational speed, the winding head wetting can vary at different rotational speeds. In order to direct the outflowing oil mist more specifically, closure plates can be attached. The mist then exits only after the closure plate has been exceeded.• Simple suction collector on one side:In the simple suction collector, the cooling medium is sucked in on the suction side and atomized on the outflow side. The atomized oil (cooling medium) is thrown outwards by the centrifugal force component and wets the winding heads. Where the oil is discharged depends on the speed and position of the suction pickup. The rotor is actively cooled, and in addition one side of the stator can be cooled. The cooling channels can be placed in the rotor in practically any desired manner. In particular, one of the advantages is thus achieved that the cooling effect on the rotor is possible in the vicinity of magnets if such are present. This is in contrast to cooling by a rotor shaft which is known from practice.• Simple suction collector on both sides:In comparison with the simple suction pickup, two suction pickups are mounted here on one side. As in the example with three additional openings, radially inner (first cooling channel openings) and outer channels (second and third cooling channel openings, not correspondingly overlapped) promote in opposite directions. The oil is thus atomized onto the end windings at both ends. The system thus has active rotor and stator cooling.• Simple pump pickup:In the pump pickups, oil is sucked by the simple suction pickup, remains inside the rotor during rotation, and is then transferred to the simple pickup. The oil actively cools the rotor. The oil which is conveyed into the receiver can additionally be provided to other cooling and lubrication points. Stator cooling by means of injection oil can likewise be realized by the width of the outlet opening. The method can also be realized with receivers and pick-ups on both sides.• Complete pump collectors:In the case of the complete pump pickups, both end faces of the rotor are covered by pick-up and pick-up. The rotor "pumps" the oil through its interior and delivers it to the receiver. The oil which is conveyed into the outlet opening can be provided to further cooling or lubrication points. Spray oil cooling can be avoided to the greatest possible extent. The complete pump consumers represent the most efficient expansion stage.• Closure plate:The exit position of the oil spray is dependent on the temperature (viscosity) and the rotational speed of the rotor. In the event that the oil mist does not reach its target at different operating points, parts of the rotor can be covered with a rotationally fixed closure plate. This can be located (viewed in the circumferential direction about the axis of rotation) in front of the desired exit point, but likewise also after the desired exit point. The shutter plates, similar to the pickups, have an air gap to the rotor.According to the invention, the following hydraulic block diagram for a cooling arrangement is obtained in particular: Examples of the hydraulic concatenation of the individual components are presented below. The components not considered in detail so far are described below.• Suction filter filters for separating coarse impurities. Usually embodied as a screen or mesh, it must not have a high pressure drop. In particular upstream of the rotor laminated core• Pressure filter filters for separating fine impurities. They are usually designed as paper or textile filters. In particular downstream of the rotor laminated core• Suction jet pump Passive pump device (operated by cooling medium which is made available by the laminated rotor core with pressure, e.g. oil mist), which makes available an additional volume flow (of cooling medium, e.g. liquid oil) via the Venturi effect in the case of high volume flows.• Oil bunker - The oil bunker has the following tasks:It provides a reservoir / It can be used for separating air bubbles, as a result of which it is possible for an oil mist to be supplied to the oil bunker and for bubble-free oil to be available after the oil bunker. / It can provide a run-on. When the rotor is stationary, oil is no longer conveyed. Depending on the provision of discharge or overflow bores on the oil bunker, the after-flow cooling can be realized by the discharged (operation by gravity) cooling medium from the oil bunker.• Cooler The cooler serves for cooling the cooling medium. It can be mounted on the suction and / or pressure side of the laminated rotor core.The invention can be summarized as follows: This yields a concept for replacing the coolant puddle. The basis here is an attachment or use of openings in the sheets of the rotor. It is also shown that the flow barriers, in a special arrangement, can also be used for the transport of the cooling medium.As a result of the rotation of the rotor, cooling medium is drawn in and transported in the direction of the rotor. Since the rotor and the pickup cannot be air-tightly sealed, cooling medium and air are sucked into the rotor. The mist resulting from this is guided through the rotor, wherein the latter is cooled. When the openings are formed by the flux barriers, the oil mist can be brought very close to the magnet.In the system of the suction pickup, the mist is atomized outwards after leaving the rotor and thus cools the winding heads. In the pump pickup system, the cooling medium can be pumped further and used for other cooling or lubricating tasks. A run-on when the rotor is stationary can likewise be represented by an oil bunker.The concept can be applied in particular to a PSM (permanent-excited synchronous machine), but it is likewise applicable to ASM (asynchronous machine) or FSM machines (externally excited synchronous motor).The advantages of the concept are:• No additional oil pump is necessary.• Simple production by punching in a sheet metal pack is possible.• Loads can be introduced directly into the casting.• Inexpensive concept with simple pickup.• High-performance concept with pump pickup.• Direct cooling at the magnets is possible.• Combined stator and rotor cooling.• Reduction of low voltage losses.• Simple integration of cooling lag.• Reduction of the installation space by elimination of the additional oil pump.• Elimination of the actuation of the oil pump (final stage, lines).Further features, effects and advantages of the invention will become apparent from the following description of a preferred exemplary embodiment of the invention and from the attached figures. In each case, a schematic schematic diagram shows: FIG. 1 shows an electric machine in a partially perspective symbol representation, FIG. 2 is a symbolic top view of a turbine, FIG. 3 shows metal sheets when flow barriers are used in the direction of the axis of rotation, FIG. 4 shows a summary top view of metal sheets according to FIGS. 3 and 5, FIG. 5 is a view according to FIG. 3 : metal sheets when using a cooling duct opening FIG. 6 and when using three additional cooling channel openings, FIG. 7 is a view according to FIG. 4 : metal sheets according to FIG. 6 , FIG. 8 shows a rotor with V-shaped interleaved partial laminated cores in plan view, FIG. 9 is a view according to FIG. 3 ; the sheets of the first three; and FIG. 10 shows the remaining three segments, FIG. 11 shows a rotor arrangement with a simple suction pickup on one side, and FIG. 12 is a view opposite to the conveying direction (rear view of FIG. 11 ); and FIG. 13 is a side view, FIG. 14 shows the rotor arrangement of FIGS. 11 to 13 with simple suction pickups on both sides in the direction of the radially outer conveying direction, FIG. 15 shows the radially inner conveying direction, and FIG. 16 is a side view, FIG. 17 shows the rotor arrangement of FIGS. 11 to 13 with a single pump pickup limited to a circumferential region in the view of FIG. 11, FIG. 18 shows FIG. 12 and FIG. 19 shows FIG. 13, FIG. 20 shows the rotor arrangement of FIGS. 17-19 with a simple pump pickup over its full circumference in the circumferential direction in a view of FIG. 17, FIG. 21 is a view similar to FIG. 18; and FIG. 22 shows FIG. 19, FIG. 23 shows the rotor arrangement of FIGS. 11 to 13 with closure element in the view of FIG. 13, and FIG. 24 shows FIG. 13, FIG. 25 shows a hydraulic block diagram of a cooling arrangement with a rotor arrangement with suction pickup, and FIG. 26 additionally shows a pump pickup.FIG. 1 shows a section of an electric machine 2 installed on a floor 94, which contains a stator 4 installed in a fixed manner on the floor 94 and a rotor 6, which rotates in an operation B in a rotational direction 8 about a rotational axis 10 (relative to the stator 4 / floor 94). Of the rotor 6, only its laminated rotor core 12 and a rotor shaft 14 are shown, which is held in a rotationally fixed manner in a central shaft receptacle 16 in the laminated rotor core 12.The rotor laminated core 12 is constructed from a plurality of axially stacked laminations 18. "Axial, radial, circumferential direction etc." refers here always to the rotational axis 10, the course of which corresponds to the "axial direction".The laminated rotor core 12 here contains a single cooling channel 20 which extends along a conveying line 22 within the laminated rotor core 12. The cooling channel 20 serves for guiding a cooling medium 24, here oil or oil mist / oil-air mixture, which itself (together with its flow direction) is indicated by arrows in FIG. 1.The cooling medium 24 is guided or conveyed or pumped in or along a conveying direction 26 through the laminated rotor core 12. The conveying direction 26 runs parallel to the axis of rotation 10, that is to say in the axial direction, and represents the proportion of movement of the direction of flow of the cooling medium 24 in the axial direction. In other words, the cooling medium 24 enters an inlet opening 30 of the cooling channel 20 at a first end side 28 aand leaves the cooling channel 20 at the other end side 28 bof the laminated rotor core 12 at an outlet opening 32 of the cooling channel 20.Each of the sheets 18 has a cooling duct opening 34, which passes through the respective sheet 18 in the axial direction, i.e. is an aperture through the sheet 18 in the axial direction. A chain or stringing of the cooling channel openings 34 with axial direction component forms the cooling channel 20.FIG. 1 shows in detail I such an overlap in the viewing direction of the conveying direction 26. The cooling channel opening 34 located "behind" in the image, i.e. remote from the observer, is shown in dashed lines. It is offset / rotated together with the relevant metal sheet 18 in a circumferential direction 38 about the rotational axis 10, here clockwise, about the rotational axis 10 by an angle of 10° with respect to the "front". Both openings therefore overlap only in a partial region of their cross section, the overlap region 36. The overlap region 36, shown shaded in FIG. 1, forms the cross section of the cooling duct 20 at this boundary surface between the two metal sheets 18.The cooling channel 20 in its entirety is thus formed by or on the basis of the alignment of the cooling channel openings 34 on the basis of the overlap regions 36 in the axial direction along the conveying line 22. The conveying line 22 is here a helical line or helix in the actual sense. Viewed in the conveying direction 26, the conveying line 22 is wound around the axis of rotation 10 counter to the direction of rotation 8, as indicated by a winding direction 40 (arrow in the circumferential direction), here over an angle range of 150° on the axial length of the laminated rotor core 12.In FIG. 1, the cooling channel openings 34 are perforations 42 in or through the laminations 18 serving specifically for forming the cooling channel 20, i.e. they are introduced or designed / designed specifically for this functionality, for this purpose: "conveying cooling medium 24" in the laminated rotor core 12.In FIG. 1, all the sheets 18 of the laminated rotor core 12 are identical and are each rotated relative to one another by 10° in the circumferential direction 38.FIG. 2 abstractly illustrates the basic principle of the invention. FIG. 2 shows a plan view of the laminated rotor core 12 during rotation in the direction of rotation 8 about the axis of rotation 10. The cooling channels 20 are therefore to be made equal in principle to intermediate spaces 52 between two of the blades 50 each. For the sake of simplicity, in FIG. 2 the cooling channels 20 and the cooling channel openings 34 generating them are illustrated obliquely and not discretely, i.e. completely aligned, in order to clearly form "smooth" and not step-shaped (see e.g. FIG. 4 ) cooling channels 20.FIG. 2 is therefore similar to the top view of a turbine which likewise rotates about the axis of rotation 10. The cooling medium 24 is shown symbolically here as individual particles, which are guided along the cooling channels 20 within the blades 50 or walls thereof. The cooling medium 24 is actually a mixture of air and liquid particles, however, i.e. an oil mist.The turbine or rotor laminated core 12 therefore transports the cooling medium 24 from right to left in FIG. 2, which corresponds to the direction of conveying 26. It can be seen here that the actual direction of movement 54 of the cooling medium 24, indicated by an arrow, has a main direction component axially in the conveying direction 26 and a further direction component in the circumferential direction 38 about the axis of rotation 10.FIG. 3 shows a section of an alternative laminated rotor core 12 in a front view, that is to say in the direction of the axis of rotation 10 / conveying direction 12. Of the sheet 18 facing the observer (shown in solid line), only an angular segment of approximately 90° is shown. In the present case, six permanent magnets 60 are located in the metal sheet 18, which are accommodated in corresponding perforations of the metal sheet 18, which perforations are not explained in more detail. Apertures 62 are also provided in the sheet metal 18, which serve as flow blocking recesses 64.In FIG. 3, an adjacent sheet 18' facing away from the observer is indicated in so far that its recesses for the permanent magnets 60 and its perforations 62' or flux blocking recess in 64' are also indicated. As explained with reference to FIG. 1, the metal sheet 18' is rotated with respect to the metal sheet 18 by a rotation angle of approximately 10° counter to the rotation direction 8. The metal sheets 18 here do not have any special cooling channel openings 34, which have been introduced / designed / designed specifically for this purpose, but rather the flow blocking recesses 64 or apertures 62 lines are also used synergetically as cooling channel openings 34.For the two illustrated (and always two axially adjacent) perforations 62, 62' or cooling channel openings 34, 34', an overlap region 36 (shaded) is again produced. Lined up in the axial direction, the overlapping regions 36 or cooling channel openings 34 result in the cooling channel 20 being joined together, as described with reference to FIG. 1.Since two different flow blocking recesses 64 overlap here, a total of two cooling channels 20 are formed according to FIG. 3, the lower one in FIG. 3 having a larger cross section than the upper one. Because of the same winding direction 40 about the axis of rotation 10, both cooling channels 20 have the same conveying direction 26. Cooling medium 24 is thus transported or pumped through the laminated rotor core 12 in the same conveying direction 26 during operation B of the rotor 6 by both cooling channels 20. FIG. 3 thus shows the use of existing flow barriers as cooling channels 20 and the principle of a one-sided pumping direction.FIG. 4 shows the situation from FIG. 3 in plan view. The rotor 6 shown or the rotor laminated core 12 is constructed here from a total of five laminated sub-cores 70 arranged axially one after the other. Symbolically indicated are the respective flux blocking recesses 64 and, as a result of successive rotation of the respective entire laminated sub-stacks 70 with respect to one another, a stepped cooling channel 20 is formed, which extends along the conveying line 22. As the actually present step shape of the cooling channel 20 approaches, the conveying line 22 is shown as a straight line.Each of the partial laminated cores 70 is an axial alignment of a plurality of laminated cores 18, which is indicated only symbolically in FIG. 4. Each of the laminated sub-stacks 70 thus contains a plurality of the axially stacked sheets 18 from FIG. 3. Within the laminated sub-stacks 70, all cooling duct openings 34 are aligned in the axial direction. Since here, too, all the sheets 18 in the entire laminated rotor stack 12 are identical, within each laminated sub-stack 70, the cooling duct openings 34 completely form the respective section of the cooling duct 20. All the sheets 18 of a respective partial laminated stack 70 are therefore likewise identical.The overlapping regions 36 are identical in cross section to the cooling channel openings 34. This results in a section of the cooling channel 20 extending straight in the axial direction within the laminated sub-stacks 70. The conveyance line 22 is provided with an arrow in FIG. 4 to indicate the flow direction of the cooling medium 24. The conveying direction 26 is entered in FIG. 4.FIG. 5 shows an alternative embodiment to FIG. 3, which provides an alternative configuration of permanent magnets 60 and flux blocking recesses 64. However, these are not used as cooling channel openings 34. Instead, the metal sheets 18 contain a separate cooling channel opening 34 in the metal sheets 18 in accordance with FIG. 1 (the metal sheet 18' facing away from the observer is again dashed). The mentioned rotation of the metal sheets 18 relative to one another about the axis of rotation 10 again produces the overlapping region 36, which has already been explained several times and is shown again shaded in FIG. 5.In accordance with the embodiment according to FIG. 1, the cooling channel openings 34 are therefore again those which have been introduced into the metal sheet 18 specifically for the purpose of forming the cooling channel 20 or the metal sheet design has therefore accordingly been provided with a cooling channel opening 34.If the rotor 6 according to FIG. 5 is likewise constructed according to FIG. 4 as an axial stringing together of partial laminated cores 70, FIG. 4 also analogously applies to the embodiment according to FIG. 5. FIG. 5 thus shows the use of a cooling channel openings 34 (which are additional to the flow blocking recesses 64) with a pumping direction (conveying direction 26) which is likewise on one side.FIG. 6 shows a modification to FIG. 5, in this case a total of three cooling duct openings 34 a- care provided for each sheet 18. The cooling channel openings 34a-c' of the adjacent sheet 18' lying "behind" again for the observer are again indicated by dashed lines. In this embodiment, two adjacent metal sheets 18, 18' have two cooling channel openings 34 b, c, which are offset in the circumferential direction 38, at the same radial distance 74 from the axis of rotation 10. However, two respectively non-corresponding cooling channel openings 34c and 34b' (and precisely not the corresponding cooling channel openings 34c and 34c') have an overlap region 36. With respect to the cooling channel openings 34a, 34a', however, corresponding cooling channel openings again have the overlap region 36, which corresponds in this respect to the embodiments according to FIGS. 1 to 5.FIG. 7 shows the arrangement from FIG. 6 in plan view again with partial laminated cores 70, insofar as the explanations relating to FIG. 4 apply analogously. This is assigned the conveying direction 26 a.The alignment of the respective cooling channel openings 34 b, c, however, results in a second cooling channel 20 balong the conveying line 22 bto which the opposite conveying direction 26 bis assigned.According to FIGS. 6 and 7, at least two adjacent sheets 18 each have two cooling channel openings 34 b, coffset in the circumferential direction 38 at the same radial distance 74 from the axis of rotation 10. Non-corresponding cooling channel openings 34 b, ceach have the overlap region 36 with one another. The laminated rotor core 12 thus has two cooling channels 20 a, b, wherein these have opposite conveying directions 26 a, bFIGS. 6 and 7 thus show the use of three additional pump openings (in addition to the flow blocking recesses 64) in the case of pumping directions on both sides (conveying directions 26 a, b, flow direction of the coolant). FIGS. 6, 7 thus show pump openings / cooling channel openings 34 b, cfor the reverse path (pump direction / conveying direction 26 b, radially outside) and pump openings / cooling channel openings 34 afor the forward path (pump direction / conveying direction 26 a, radially inside).FIG. 8 shows an alternative rotor 6 with a laminated rotor core 12 on the rotor shaft 14 in plan view and in detailed form. A mirrored rotation of the partial laminated cores 70 (segments) with respect to the arrangement of their permanent magnets 60 is indicated here. the three segments in the figure are arranged to the left of a mirror line 78 in this case in a mirrored manner with respect to the three partial laminated cores 70 or segments to the right of the mirror line 78. The mirrored course of the magnet arrangement is symbolized by arrows 80 in FIG. 8. It can be seen by viewing these arrows 80 that here no simple channel formation in the laminated rotor core 12 (formation of a cooling channel 20, which would also be V-shaped in the case of identical sheets 18, as a result of which no media transport axially through the laminated rotor core 12 is possible).In order to be able to represent a pumping power in an axial conveying direction 26 nevertheless, the principle of three additional cooling channel openings 34 a- cof FIGS. 6 and 7 is used in a modified form: in relation to FIGS. 6 and 7, it was described how a pumping action in two conveying directions 26 a, bmay be represented with rotation of the partial laminated cores 70 in the same direction.In this modification, the sheet metal sections of the sheets / sheets 18 in the three left segments / partial sheet stacks 70 according to FIG. 8 are embodied differently from the sheet metal sections of the three right segments / partial sheet stacks 70 in FIG. 8. However, all three pump openings are at the same radial distance 74 here, not as in FIG. 9 ; in other words, this results in a mirrored direction of rotation in the case of long rotors.FIG. 9 shows the sheets 18 of the left three partial laminated cores 70 from FIG. 8, in the transferred sense the cooling channel openings 34 aof FIG. 6 are at a specific radial distance 74 from the axis of rotation 10.FIG. 10, on the other hand, shows the sheets 18 of the three right partial laminated cores 70 from FIG. 8, which are designed differently. These have the same effect as the two cooling channel openings 34 b, cof FIG. 6, but likewise at the same radial distance 74 from the axis of rotation 10 as that of FIG. 9.FIGS. 9 and 10 show the two metal sheets 18, but from the view onto the respective end face. With reference to FIG. 8, the viewing direction is directed to the one metal sheets 18 (e.g. FIG. 9 ) from the left and to the other metal sheets (e.g. FIG. 10 ) from the right.FIG. 11 shows a rotor arrangement 90 which contains an embodiment of the rotor laminated cores 12 explained hitherto and a guide means 92 for the cooling medium 24. the guide means 92 is installed fixedly at rest with respect to the base 94. During operation B, the rotor 6 with rotor shaft rotates about the axis of rotation 10 again in the direction of rotation 8.FIG. 11 shows a view of the one end face 28 aof the laminated rotor core 12, which in this embodiment contains a total of eight 8 cooling channels 20, of which the inlet openings 30 are visible in each case, via which cooling medium 24 (not shown in the figure, oil mixed with air) is sucked into the laminated rotor core 12 or the cooling channels 20 during operation B.The guide means 92 is configured to guide the cooling medium 24 with respect to the laminated rotor core 12, namely here for feeding to the laminated rotor core 12. The guide means 92 is here a so-called suction pickup 102, which therefore does not rotate with the laminated rotor core 12 during operation B. The guide means 92 contains a line section 96, indicated only by a dashed line in FIG. 11, for guiding cooling medium 24. the line section 96 has a line end 98, which faces the end face 28 aof the laminated rotor stack 12. The line end 98 is configured to supply cooling medium 24 to the front openings 29, here to the inlet openings 30, of the cooling channels 20. In other words, the line end 98 is here a suction opening.FIG. 12 shows the view of the rotor arrangement 90 from the opposite direction to FIG. 11, namely the view of the opposite end face 28 bof the laminated rotor core 12 and thus the end openings 29 in the form of the outlet openings 32 of the cooling channels 20; FIG. 12 shows symbolically indicated how cooling medium 24, here oil, exits from the cooling channels 20 or outlet openings 32 in the form of oil spray after it has been conveyed through the cooling channels 20 by the rotation of the laminated rotor core 12.FIG. 13 shows the rotor arrangement 90 in a side view / lateral cross section. The cooling channel 20 passing through the laminated rotor core 12 is only symbolically indicated here in the axial direction. In cross section, the line section 96 can now also be seen in the guide means 92, which ends at the line end 98.In the simple suction collector illustrated here in the form of the guide means 92, the cooling medium 24 is sucked in from the laminated rotor core 12 on a suction side, in this case the end side 28 a, and atomized on the outflow side thereof, in this case the end side 28 b. The atomized cooling medium 24, here oil, is thrown outwards by the centrifugal force component and wets the winding heads of the stator 6, which are not shown. Wo, i.e. at which circumferential position the oil or cooling medium 24 flows out, is dependent on the rotational speed and the position of the suction pickup in the form of the guide means 92 and the temperature of the oil or its viscosity.The rotor 6 is thus actively cooled; in addition, one side of the not-shown stator 4 can be cooled. The conveying direction 26 is indicated by an arrow. The coolant 24 is stored in a reservoir 100 here in order to be removed from there through the line section 96 and to collect again there after leaving the laminated rotor core 12.FIGS. 11 to 13 thus show a single suction pickup 102 on one side.FIGS. 14 to 16 show a modification of the situation from FIGS. 11 to 13, wherein the rotor arrangement 90 contains a second guide means 92 in the form of the suction pickup 102 on the end face 28 b. This is constructed in principle like the suction collector 102 from FIGS. 11 to 13, but here uses nine further additional cooling channels 20 lying radially further inward or their inlet openings 30. The radially inner cooling channels 20 have a conveying direction 26 bfrom the end face 28 bto the end face 28 a. The radially outer cooling channels 20 according to FIGS. 11 to 13, on the other hand, again have the conveying direction 26 afrom the end face 28 ato the end face 28 b.FIG. 14 thus shows the cooling medium 24 emerging from the radially inner outlet openings 32 in the form of an oil spray, again indicated by dots or droplets. FIG. 15 shows the coolant 24 emerging from the radially outer outlet openings 32, likewise as an oil spray.FIGS. 14 to 16 thus show two suction cups 102 in comparison with the simple suction cup 102 according to FIGS. 11 to 13.As shown above in the example with the three additional openings (cooling channel openings 34 a- c) according to FIGS. 6 and 7, the inner radially inner cooling channel openings 34 aand the radially outer cooling channel openings 34 b, cor the inner and outer cooling channels 20 convey in respectively opposite directions, i.e. in opposite directions.The cooling medium 24 or oil is thus atomized onto the winding heads, not shown, at both ends of the rotor 6. The system or rotor arrangement 90 thus has an active rotor and stator cooling.In FIGS. 13, 16 and 19, the exiting oil, in the form of droplets, is not shown for the sake of clarity. However, this results from the positionally correct representations in FIGS. 11 and 12, 14 and 15, 16 and 17. However, due to the twisting, it is the case that these scatter at a position of 12 o'clock (FIGS. 14 and 15 ).FIGS. 17 to 19 show an alternative modification of the rotor arrangement 90 from FIGS. 11 to 13 to FIGS. 14 to 16, wherein a suction pick-up 104 is provided on the end face 28 bas a guide means 92 in addition to the suction pick-up 102. The suction pick-up 104 is also installed in a fixed position relative to the floor 94. This also has a line end 98 and a line section 96. However, the suction pick-up 104 is configured to discharge cooling medium 24 from the end openings 29 here in the form of the outlet openings 32 into the line section 96. Suction pickup 102 and suction pickup 104 thus represent simple pump pickups. In the pump pickups shown, coolant 24 is sucked by the simple suction pad 102, remains inside the rotor 6 during rotation, and is then transferred to the simple suction pad 104. In this case, the cooling medium 24 actively cools the rotor 6. The cooling medium 24, which is conveyed into the suction receiver 104, can additionally be provided to other cooling and lubrication points, not shown, via the line section 96 or its continuing extension or continuing line. Stator cooling by means of injection oil can likewise be realized by the width of the outlet openings 32. The method can also be implemented (not shown) with suction pick-up and pick-up devices on both sides, analogously to FIGS. 14 to 16 For this purpose, the radially inner cooling channels 20 are then also equipped with a respective suction pick-up 102 and suction pick-up device 104, which however are then attached again to respectively opposite end sides 28 a, b.In FIGS. 11 to 19, the line end 98 in the guide means 92 is in each case limited to a circumferential region 106 about the axis of rotation 10, as is indicated in FIG. 17 as representative of the relevant embodiments.In contrast to this, FIGS. 20 to 22 show, only for the embodiment selected by way of example according to FIGS. 17 to 19, a so-called complete pump pickup, i.e. complete suction pickup 102 and suction pickup 104. The respective line end 98 extends over the entire circumference around the axis of rotation 10. In the illustrated complete pump removal, both end faces 28 a, bof the rotor 6 are completely covered circumferentially by suction pick-up 104 or suction pick-up 102, not only in the circumferential region 106. The rotor 6 pumps the cooling medium 24 through its interior and conveys it to the suction receiver 104. The cooling medium 24, which is conveyed into the outlet openings 32, can thus be made available via the line section 96 of the suction receiver 104 to further cooling or lubrication points, not shown. Spray cooling can be avoided to the greatest possible extent in this case. The complete pump pickups constitute the most efficient stage of expansion for a rotor 6 with pumping action.Finally, FIGS. 23 and 24 show a rotor arrangement 90 with an alternative guide means 92 in the form of a closure element 110 which does not rotate with the laminated rotor core 12. FIG. 23 shows, in addition to the suction pickup 102 according to FIGS. 11 to 13, the closure element 110, here in the form of a closure plate. This has a closure surface 112. The closure element 110 is also installed in a fixed position relative to the base 94.The closure plate can also be used with simple pump consumers (FIGS. 17 to 19 ).FIG. 23 illustrates how cooling medium 24 is prevented from flowing out of the outlet openings 32 in the region of the closure surface 110. FIG. 23 shows, in comparison with FIG. 12, that the outflow in the region of the closure surface 110 is prevented.Here too, the exit position of the cooling medium 24 in the form of the oil spray is dependent on the temperature (viscosity) and the rotational speed of the rotor 6. This can be located before the desired exit location with respect to the rotational direction 8, as shown in FIG. 23, but likewise also (not shown) after the desired exit location.For all embodiments, the following applies: the closure element 110 or, more precisely, its closure surface 112 and the suction pickups 102 and suction pickups 104, more precisely their line ends 98, are each spaced apart from the rotor 6 / rotor laminated core 12 or its end faces 28 a, bvia an air gap 114.FIG. 25 shows a cooling arrangement 120 for the electric machine 2. arrows indicate the flow direction of the cooling medium 24, wherein solid arrows stand for liquid cooling medium 24, here oil, arrows shown in dotted lines mark a mixture of cooling medium 24 and air, namely here an oil mist. The reservoir 100 already explained contains a supply of liquid cooling medium 24, which is sucked from the reservoir 100 by the suction collector 102 or its (extended) line section 96 from the front end 28 aof the laminated rotor core 12. In this case, the cooling medium 24 passes through an optional suction filter 122 and an optional cooler 124. The rotor 6 acts as a rotor pump as explained above and discharges the coolant 24 at its front end 28 b. The cooling medium 24 now serves for the symbolically represented stator cooling 126 and bearing lubrication 128 and returns to the reservoir 100 after fulfilment of its task. The arrangement corresponds to that of FIGS. 11 to 13, and FIG. 25 thus shows a hydraulic block diagram for suction pickup 102.FIG. 26 shows a cooling arrangement 120 which has a rotor arrangement 90 according to FIGS. 17 to 19, namely both suction pick-up 102 and suction pick-up 104. In addition to the illustration from FIG. 25, a pressure filter 130 and a suction jet pump 132 are also provided here, which is supplied with cooling medium 24, also here again in the form of oil mist, from the continued line section 96 of the suction pick-up 104. Driven by the cooling medium 24 supplied under pressure in the form of the oil mist (dotted line), the suction jet pump 132 draws in additional liquid cooling medium 24 (solid line), which is thus introduced into a cooling medium hopper 134 (oil hopper) and stored there. Here too, the cooling medium 24 again serves for stator cooling 126 and bearing lubrication 128. There is also the option, not shown, that the suction jet pump 132 only conveys into the cooling medium hopper 134, which then supplies everything else. It is likewise conceivable, as illustrated, or also (likewise not illustrated) without cooling medium bunker 134.The cooling medium hopper 134 is configured such that it can be emptied or emptied solely by means of gravity 136, indicated by arrows. Thus, cooling medium 24 passes from the latter to stator cooling 126 or bearing lubrication 128, even after rotor 6 has stopped and no longer develops a pumping effect, i.e., no further cooling medium 24 is conveyed further.Reference numerals denote reference numerals2 Machine (electrical) 4 Stator 6 Rotor 8 Rotational direction 10 Rotational axis 12 Rotor laminated core 14 Rotor shaft 16 Shaft receptacle 18 Sheet 20 Cooling duct 22 Conveying line 24 Cooling medium 26 Conveying direction 28 a,b End face 29 End opening 30 Inlet opening 32 Outlet opening 34 Cooling duct opening 36 Overlapping region 38 Circumferential direction 40 Winding direction 42 Aperture 50 Blade 52 Intermediate space 54 Direction of movement 60 Permanent magnet 62 Aperture 64 Flux blocking recess 70 Laminated sub-cores 74 Radial spacing 78 Mirror line 80 Arrow 90 Rotor arrangement 92 Guide means 94 Base 96 Line section 98 Line end 100 Reservoir 102 Suction collector 104 Suction collector 106 Circumferential region 110 Closure element 112 Closure surface 114 Air gap 120 Cooling arrangement 122 Suction filter 124 Cooler 126 Stator cooling 128 Bearing lubrication 130 Pressure filter 132 Suction jet pump 134 Cooling medium bunker 136 Gravity B OperationReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 199 05 540 A1

[0003]

Claims

Laminated rotor core (12) for a rotor (6) of an electric machine (2) rotating in an axial direction (8) about an axis of rotation (10) during operation (B), - having at least one cooling duct (20) which extends along a conveying line (22) between two end openings (29) and is configured to guide a cooling medium (24) in an axial conveying direction (26) through the laminated rotor core (12), - wherein the laminated rotor core (12) has a plurality of axially stacked sheets (18), - wherein each of the sheets (18) has at least one cooling duct opening (34) as part of one of the cooling ducts (20), - wherein in each case at least one of the cooling duct openings (34) of two adjacent sheets (18) overlaps in a respective overlapping region (36), and - the respective cooling duct (20) is formed by an axial alignment of the cooling duct openings (34) on the basis of the overlapping regions (36) along the conveying line (22), wherein the conveying line (22) is a helical line which, viewed in the conveying direction (26), is wound counter to the rotational direction (8) about the rotational axis (10).Laminated rotor core (12) according to Claim 1, characterized in that at least one of the cooling duct openings (34) is at least part of a flux blocking recess (64) in the laminated core (18).Laminated rotor core (12) according to one of the preceding claims, characterized in that at least one of the cooling duct openings (34) is an aperture (62) in the sheet (18) serving specifically for forming the cooling duct (20).Laminated rotor core (12) according to one of the preceding claims, characterized in that at least two adjacent ones of the laminations (18) have in each case at the same radial distance (74) from the axis of rotation (10) at least two cooling duct openings (34) offset in the circumferential direction (38) and non-corresponding cooling duct openings (34) have the overlapping region (36) with one another.The laminated rotor core (12) according to any one of the preceding claims, characterized in that the laminated rotor core (12) contains at least two laminated sub-cores (70) arranged axially one after the other, wherein each of the laminated sub-cores (70) contains a plurality of the axially stacked sheets (18).Laminated rotor core (12) according to Claim 5, characterized in that within at least one of the laminated sub-cores (70) the cooling duct openings (34) are aligned in the axial direction.Laminated rotor core (12) according to one of Claims 5 to 6, characterized in that all the laminations (18) of at least one of the laminated sub-cores (70) are identical.Laminated rotor core (12) according to one of the preceding claims, characterized in that all the laminations (18) of the laminated rotor core (12) are identical.Laminated rotor core (12) according to one of the preceding claims, characterized in that the laminated rotor core (12) has at least two cooling ducts (20), at least two of the cooling ducts (20) having opposite conveying directions (26).Rotor arrangement (90), - with the laminated rotor core (12) according to one of the preceding claims, and - with a guide means (92) for the cooling medium (24) which is set up during operation (B) for guiding the cooling medium (24) in relation to the laminated rotor core (12).Rotor arrangement (90) according to Claim 10, characterized in that at least one of the guide means (92) is a suction collector (102) or suction collector (104) which does not rotate with the laminated rotor core (12) during operation (B) and which contains a line section (96) having a line end (98) which faces one of the end faces (28a, b) of the laminated rotor core (12) and is designed to feed cooling medium (24) to the end openings (29) of the cooling channels (20) from the line section (96) or to discharge it therefrom into the line section (96).Rotor arrangement (90) according to Claim 11, characterized in that - the line end (98) is bounded to a circumferential region (106) around the axis of rotation (10), or - the line end (98) extends over the entire circumference around the axis of rotation (10).Rotor arrangement (90) according to one of Claims 10 to 12, characterized in that at least one of the guide means (92) is a closure element (110) which does not rotate with the laminated rotor core (12) during operation (B) and has a closure surface (112) which faces one of the end faces (28a, b) of the laminated rotor core (12) and which is designed to prevent cooling medium (24) from flowing into or out of the end openings (29) of the cooling ducts (20) at the closure surface (112).Cooling arrangement (120) for an electric machine (2), - with the laminated rotor core (12) according to one of Claims 1 to 9 or - with the rotor arrangement (90) according to one of Claims 10 to 13, - with a reservoir (100) for cooling medium (24), and - with a suction line which is configured to feed cooling medium (24) from the reservoir (100) to the laminated rotor core (12).Cooling arrangement (120) according to Claim 14, characterized in that the cooling arrangement (120) contains - a suction filter (122) arranged between the reservoir (100) and the laminated rotor core (12) upstream of the laminated rotor core (12) and / or - a cooler (124) for cooling the cooling medium (24) and / or - a pressure filter (130) arranged between the laminated rotor core (12) and the reservoir (100) downstream of the laminated rotor core (12) and / or - a suction jet pump (132) which is operated during operation (B) by cooling medium (24) emerging from the laminated rotor core (12) or entering it, and / or - a cooling medium hopper (134) which is designed to be filled with cooling medium (24) by the laminated rotor core (12) during operation (B), which can be emptied of cooling medium (24) by gravity (136) in order to provide a flow of cooling medium (24) independently of the operation (B) of the laminated rotor core (12).

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