Stator for an electric machine, method for manufacturing said stator and automotive part comprising such a stator - Patent application

Abstract

The invention relates to a stator (1) for an electric machine, comprising an annular stator body (3) defining a longitudinal central axis (2), on whose outer peripheral side surface (4) longitudinal ribs (5) projecting radially outwardly away from each other and longitudinal cooling passages (6) defined by the longitudinal ribs (5) through which a cooling fluid can be passed, the stator (1) comprising an annular outer housing sleeve (7) axially covering the stator body (3). It is essential for the invention that the stator body (3) with the longitudinal ribs (5) is fixed in the outer housing sleeve (7) from the radially inner side in a frictionally coupled manner. The invention further relates to a method for manufacturing such a stator (1) and to an automotive component for an automotive vehicle comprising the stator (1).

Description

[Technical field]

[0001] The present invention relates to a stator for an electric machine according to the preamble of claim 1. Furthermore, the present invention relates to a method for producing a stator and to a vehicle component comprising a stator.

[0002] Typical stators are described, for example, in DE 102017221808 A1 and US 2020153292 A1. A disadvantage of these stators is that in order to be able to reliably transmit torque from the stator to its outer housing sleeve or outer housing, the stator needs to be fixed to the stator outer housing sleeve or outer housing in a non-rotatable manner with considerable design effort, as a result of which the corresponding stators have a relatively large structure and are expensive.

[0003] The object of the present invention is therefore to specify an improved or at least alternative embodiment for a stator. In particular, it is attempted to specify a stator which can be produced relatively economically and compactly. The present invention specifies a method for producing such a stator and at the same time solves the above-mentioned problem.

[0004] According to the invention, these problems are solved in particular by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims and the description.

[0005] The basic idea of ​​the present invention is to fix the stator to the outer housing sleeve or outer housing by frictional engagement so that it cannot rotate relative to the housing. Preferably, the space between the overmolded stator body and the outer housing sleeve is used to provide a number of longitudinal cooling passages for direct cooling applications (i.e., for a water-glycol mixture), which preferably have a number of reinforcement surfaces (i.e., ribs and / or baffles for coolant disruption) manufactured and provided by the overmolding material used to seal the stator body.

[0006] With this in mind, the invention proposes that a stator for an electric machine, in particular for a liquid-cooled electric drive motor, has an annular stator body defining a longitudinal center axis, on whose outer peripheral side surface directed radially outward with respect to the longitudinal center axis there are arranged longitudinal ribs projecting radially outward and longitudinal cooling passages defined by the longitudinal ribs, which can be circulated by a cooling fluid in a meandering manner, in particular in the axial direction, with respect to the longitudinal center axis. Furthermore, the stator comprises an annular outer housing sleeve or outer housing, which is axially or coaxially placed on the stator body. It is important that the stator body with the longitudinal ribs is frictionally fixed from the radial inside to the outer housing sleeve so that it cannot rotate relative to it. This allows torque to be transmitted frictionally from the stator body to the outer housing sleeve or outer housing without play and slip. This has the advantage that additional torque transmission means can be dispensed with, as a result of which the stator according to the invention can be designed to be relatively compact and lightweight.

[0007] Preferably, an annular outer housing sleeve is frictionally locked onto the stator body. More preferably, the outer housing is shrink fitted onto the overmolded stator body. Alternatively, the outer housing can be glued in place (i.e., hot melt adhesive) or locked in place by a form-fitting connection with the stator body and / or end plates.

[0008] Here, the outer housing sleeve or outer housing may surround the stator body in a predetermined area or completely in the circumferential direction about the longitudinal center axis and in at least a predetermined area or completely in the axial direction with respect to the longitudinal axis. The outer housing sleeve may be part of the outer housing or may form part of the outer housing.

[0009] It is practical if the longitudinal ribs are radially preloaded and bear against the outer housing sleeve, which allows the torque transmitted from the stator body to the outer housing sleeve to be optimized or increased. This results from the fact that the maximum torque that can be transmitted via the longitudinal ribs is practically proportional to the static friction, in particular at the contact surface between the longitudinal ribs with the baffles and the outer housing sleeve, and to the radial preload.

[0010] Furthermore, it is practical if each of the longitudinal ribs has a rib front surface directed radially outward, which is flat or curved about the longitudinal central axis, and via which the stator body is supported in contact with the inner peripheral side surface of the outer housing sleeve in a predetermined area. Furthermore, each of the longitudinal ribs may practically have two rib side surfaces extending in the direction of the longitudinal central axis, which rib side surfaces are directed opposite each other in the circumferential direction about the longitudinal central axis and are preferably aligned parallel to each other or inclined to each other. The rib side surfaces of the longitudinal ribs may be connected to each other via the rib front surfaces of the longitudinal ribs. This allows the rib front surfaces to define a total collective area through which torque can be transmitted from the stator body to the outer housing sleeve. If the longitudinal ribs extend over the entire longitudinal length of the stator body, the optimum width of the rib front faces in the circumferential direction can be determined empirically, for example through tests, where the relationship may apply that for a relatively large total collective area, i.e. for a relatively large area of ​​the rib front faces, a smaller surface pressure on the longitudinal ribs is achievable if the torque remains the same, or vice versa. It is clear that the maximum transmittable torque is practically limited only by the static friction between the longitudinal ribs or their front faces and by the radial preload, but not by the total collective area of ​​the rib front faces or the inner peripheral side surface of the outer housing sleeve or the contact area formed between the rib front faces and the inner peripheral side surface of the outer housing sleeve.

[0011] In practice, the longitudinal ribs may be arranged on the stator body spaced apart from one another in the circumferential direction about the longitudinal central axis, with one longitudinal cooling passage being defined in each case between two longitudinal ribs that are directly adjacent to one another in the circumferential direction. This describes a preferred embodiment for a stator in which the longitudinal ribs extend longitudinally in a cage wheel manner in practice over the entire longitudinal length of the outer peripheral side surface of the stator body.

[0012] In practice, there are different embodiments for such a stator. For example, the stator has a pin fin structure and / or longitudinal ribs and / or transverse ribs, etc. Preferably, the stator with the pin fin structure and / or longitudinal ribs and / or transverse ribs is formed using an overmolding process to form a reinforced surface. It is important that these longitudinal ribs, which are preferably used to disrupt the coolant flow to improve thermal performance, are manufactured by an overmolding process. Preferably, the longitudinal ribs form a serpentine structure, which only slightly increases the pressure drop (since all the passages on the outside of the stator stack are connected in parallel). In this case, the thermal performance of the stator stack cooling is improved by more than 20%.

[0013] Preferably, said longitudinal ribs and / or cooling fluid guiding projections are formed by a baffle.

[0014] Moreover, preferably, these baffles, particularly the longitudinal ribs and / or cooling fluid guide protrusions, are primarily used to disrupt coolant flow to improve thermal performance and are manufactured by an overmolding process.

[0015] Furthermore, the longitudinal ribs may be arranged on the stator body spaced apart from one another in a circumferential direction about the longitudinal central axis, such that the number of longitudinal ribs corresponds to the number of stator teeth arranged on the radially inner circumferential side of the stator body for supporting the stator windings of the stator. It is clear that there may be more or less transverse ribs than the stator body has stator teeth.

[0016] Preferably, the number and / or shape of the longitudinal cooling passages on the outer surface of the stator body is merely a design choice, in another embodiment, the longitudinal cooling passages can be formed circumferentially, since the longitudinal cooling passages and the longitudinal rib or baffle structures are manufactured by overmolding, so that even more complex shapes of the passages have a great deal of design freedom.

[0017] Preferably, the longitudinal cooling passages are provided essentially by the overmolding process of the stator body.

[0018] Furthermore, practically, the longitudinal ribs and the stator body can form a monolithic component. In other words, the longitudinal ribs and the stator body are an integral embodiment. This allows the stator to be manufactured relatively inexpensively. Practically, the stator body, in particular the outer peripheral side of the stator body, can be overmolded with plastic material, so that the longitudinal ribs and the longitudinal cooling passages are covered at least in certain areas or completely by the plastic material cover. Practically, the plastic material cover can be at least several thousand or several hundred or several tens of millimeters thick and / or can be sprayed over the entire stator body with a uniform thickness. Advantageously, the molded plastic material cover has a minimum thickness of 0.15 mm, in particular depending on the size of the filling material. For practical reasons, the nominal thickness in all areas where no insulation penetration is required can be 0.2 mm. The overmolding can be realized, for example by plastic injection molding, when transfer molding is used. Furthermore, it is conceivable that the plastic material cover has at least local thickness variations. In particular, it may be provided that the thickness of the plastic material cover on the rib front faces of the radially longitudinal ribs is smaller than the thickness of the plastic material cover on the cooling passage bottoms of the radially longitudinal cooling passages. By means of a suitable overmolding with plastic material, the stator body can be sealed against the cooling fluid, for example in order to provide a corrosion-resistant coating.

[0019] For water-glycol cooling, one of the challenges is to ensure corrosion protection, and the entire stator body may be coated with at least a thin skin of plastic material.

[0020] Preferably, the longitudinal cooling passages and / or the longitudinal ribs form a baffle structure.

[0021] Furthermore, it is practical if the longitudinal ribs extend completely over the stator body in the axial direction with respect to the longitudinal central axis. The rib longitudinal length of the longitudinal ribs may therefore correspond to the axial longitudinal length of the stator body. In other words, practically, the axial length of the longitudinal ribs and / or the length of the longitudinal cooling passages is at least the same as the length of the stator stack. However, it may alternatively be provided that the longitudinal ribs extend axially over a maximum of 50% of the stator body with respect to the longitudinal central axis or over a minimum of 50% and a maximum of 90% of the stator body. The rib longitudinal length of the longitudinal ribs in these cases may therefore correspond to a maximum of 50% or a minimum of 50% and a maximum of 90% of the axial longitudinal length of the stator body. Alternatively, the longitudinal ribs may extend axially over only 70% and a maximum of 95% of the longitudinal length of the stator body. The longitudinal ribs are thus either of equal length in the axial direction relative to the longitudinal axis as the stator body or of slightly shorter length in the axial direction relative to the longitudinal axis, so that installation space for cooling supply equipment, e.g. coolant supply lines or coolant deflection chambers, can be provided in front of and / or behind the longitudinal ribs in the axial direction in the stator or stator body.

[0022] Furthermore, due to the fact that the insulating material, e.g. the above-mentioned plastic material, is also applied to the front and rear faces of the stator body, the axial length of the longitudinal cooling passages is in fact larger than the stator body length, e.g. 2×0.2 mm added to the stator body length. Furthermore, the length of the longitudinal cooling passages may be substantially larger than the stator body length of the stator body.

[0023] The longitudinal ribs may have a rib cross-section oriented transversely with respect to the central longitudinal axis, the rib cross-section being configured substantially rectangular. It is practical if the rib cross-section of the longitudinal ribs is constant at each longitudinal position in the direction of the central longitudinal axis.

[0024] The longitudinal cooling passages may have a passage cross-section oriented transversely with respect to the central longitudinal axis and configured substantially rectangular, the passage cross-section of the longitudinal ribs being practically constant at each longitudinal position in the direction of the central longitudinal axis.

[0025] In practice, the passage cross section of the longitudinal cooling passages can also be configured to be larger based on the rib cross section of the longitudinal ribs.

[0026] It may be provided that the stator body comprises cooling fluid guide protrusions, which are arranged in the longitudinal cooling passages, in which they interact in a flow-guiding manner with the cooling fluid flowing therethrough. As a result, the cooling fluid flow of the cooling fluid flowing through the longitudinal cooling passages can be particularly influenced in terms of flow. For example, it can be achieved that the cooling fluid flows through the longitudinal cooling passages in an axially meandering manner relative to the longitudinal central axis. As a result, the cooling fluid guide protrusions can interact with the cooling fluid flowing therethrough or can generate vortices or turbulences, which can advantageously improve the cooling effect.

[0027] It may further be provided that the cooling fluid guiding protrusions are arranged in the longitudinal cooling passages at an angle, for example at an angle of 45° or at a right angle, respectively, with respect to the longitudinal ribs and / or the longitudinal central axis and / or the longitudinal cooling passages, whereby the cooling fluid flow of the cooling fluid can also be particularly influenced in terms of flow, for example in order to improve the heat dissipation by the cooling fluid.

[0028] Furthermore, the cooling fluid guide projections may be arranged on the longitudinal ribs respectively and may extend from these longitudinal ribs into the longitudinal cooling passages. The cooling fluid guide projections are practically molded on the longitudinal ribs, for example, if they are separate components and / or are integrally formed with the longitudinal ribs and extend from these longitudinal ribs into the longitudinal cooling passages adjacent to the respective longitudinal ribs. Here, the cooling fluid guide projections may extend on the cooling passage bottom of the longitudinal cooling passages on the base side, and, if applicable, said cooling fluid guide projections may be molded on the cooling passage bottom and / or be implemented integrally with the cooling passage bottom. This may also improve the heat dissipation through the cooling fluid.

[0029] It is practical if the cooling fluid guide protrusions on the cooling passage bottom of each longitudinal cooling passage are made wider than on the side of the cooling fluid guide protrusion facing away from the cooling passage bottom. Each cooling fluid guide protrusion may for example have a relatively wide cooling fluid guide protrusion base arranged at the cooling passage bottom and a relatively narrow cooling fluid guide protrusion head facing away from the cooling passage bottom, with a conical profile between the cooling fluid guide protrusion base and the cooling fluid guide protrusion head of the cooling fluid guide protrusion being preferred. The cooling fluid guide protrusions may be inclined or sloped, preferably with respect to the longitudinal central axis of the stator body and / or with respect to the circumferential lateral surface.

[0030] Furthermore, the cooling fluid guide protrusions may be entirely formed or realized from plastic material. Alternatively or additionally, the cooling fluid guide protrusions may be manufactured together with the plastic material cover as part of an overmolding of plastic material on the stator body, in particular on the outer peripheral side of the stator body, so that the cooling fluid guide protrusions and the plastic material cover form an integral unit. The cooling fluid guide protrusions may therefore be formed entirely from plastic and preferably realized integrally with said plastic material cover. Here, it may be practically appropriate to form said plastic material cover and the cooling fluid guide protrusions in a single common process step as parts of a plastic injection moulding. It is also clear that the plastic material cover and the cooling fluid guide protrusions may be manufactured in different process steps as parts of a plastic injection moulding, so that, for example, a different plastic material may be used for the plastic material cover than the plastic material for the cooling fluid guide protrusions. The production of the cooling fluid guide protrusions may thus be carried out relatively cost-effectively, for example by plastic injection moulding.

[0031] In practice, the cooling fluid guide protrusions may have a cooling fluid guide protrusion length in their respective main extension direction which is at least 10% of the cooling passage width of the longitudinal cooling passages, in particular measured in the circumferential direction around the longitudinal central axis. Alternatively, the cooling fluid guide protrusions may have a cooling fluid guide protrusion length which is at most 90% of the cooling passage width of the longitudinal cooling passages, in particular measured in the circumferential direction around the longitudinal central axis. Furthermore, the cooling fluid guide protrusion length of the cooling fluid guide protrusions may be at least 10% to at most 90% of the cooling passage width of the longitudinal cooling passages, in particular measured in the circumferential direction around the longitudinal axis. The cooling passage width of the longitudinal cooling passages may be the width of the longitudinal cooling passages through which the flow can be passed, which extends perpendicularly with respect to the longitudinal ribs and / or with respect to the longitudinal central axis. Thereby, the length of the cooling fluid guide protrusions can be pre-set as it were, so that the cooling fluid flow of the cooling fluid can be particularly influenced with respect to the flow.

[0032] In practice, the cooling fluid guide protrusion lengths of all the cooling fluid guide protrusions may be realized to be the same.

[0033] It is furthermore practical if the cooling fluid guide protrusion has a cooling fluid guide protrusion width oriented in a vertical direction with respect to the cooling fluid guide protrusion length that is at least 10% of the cooling fluid guide protrusion length. Alternatively, the cooling fluid guide protrusion may have a cooling fluid guide protrusion width oriented in a vertical direction with respect to the cooling fluid guide protrusion length that amounts to a maximum of 90% of the cooling fluid guide protrusion length. Furthermore, the cooling fluid guide protrusion width of the cooling fluid guide protrusion may be at least 10% to a maximum of 90% of the cooling fluid guide protrusion length of this cooling fluid guide protrusion. This indicates a preferred width for the cooling fluid guide protrusion.

[0034] Practically, the cooling fluid guide protrusion widths of all the cooling fluid guide protrusions may be realized to be the same.

[0035] Cooling fluid guide projections may in each case be arranged on the longitudinal ribs of the stator body, and practically at least one separate cooling fluid guide projection may be arranged on each longitudinal rib, which practically extend starting from the respective longitudinal rib on which they are arranged into the longitudinal cooling passages immediately adjacent to this longitudinal rib, in other words, each of these longitudinal ribs is assigned a cooling fluid guide projection, which extends into the longitudinal cooling passage.

[0036] Practically, it may further be provided that the cooling fluid guiding protrusions protrude starting from the respective longitudinal rib on which they are arranged into the longitudinal cooling passage adjacent to the respective longitudinal rib in such a way that at least one cooling fluid guiding protrusion is assigned to each longitudinal cooling passage, so that each longitudinal cooling passage has at least one cooling fluid guiding protrusion, by which the cooling fluid flow of the cooling fluid flowing through the longitudinal cooling passage can be optimally influenced.

[0037] Furthermore, it may also be provided, additionally or alternatively, that a number of cooling fluid guide projections are arranged on the respective longitudinal ribs, which are arranged on the respective longitudinal ribs axially spaced apart from one another in the longitudinal direction relative to the central longitudinal axis, where it is practical if the cooling fluid guide projections of the respective longitudinal ribs axially extend alternately relative to the central longitudinal axis, i.e. alternately in the axial direction, in a circumferential direction about the central longitudinal axis, into a longitudinal cooling passage adjacent to the respective longitudinal rib in this circumferential direction and, in a counter-circumferential direction opposite to the aforementioned circumferential direction, into another longitudinal cooling passage adjacent to the respective longitudinal rib in the counter-circumferential direction.

[0038] Additionally or alternatively, the cooling fluid guide protrusions projecting in the circumferential direction into the longitudinal cooling passages are located in a first plane, and the cooling fluid guide protrusions projecting in the opposite circumferential direction into the other longitudinal cooling passages are located in a second plane, the first and second planes are arranged in alternating axial order with respect to the longitudinal central axis and are spaced apart from one another with respect to the longitudinal central axis, and one of the first planes is assigned to a cooling fluid guide protrusion projecting in the circumferential direction into the longitudinal cooling passages that are directly adjacent to one another in the circumferential direction, and one of the second planes is assigned to a cooling fluid guide protrusion projecting in the opposite circumferential direction into the longitudinal cooling passages that are directly adjacent to one another in the opposite circumferential direction, thereby achieving in practice a stator shape in which the cooling fluid guide protrusions are each located on a plane extending perpendicularly to the longitudinal central axis. This describes a preferred shape of the cooling fluid guide protrusions that can optimally influence the cooling fluid flow of the cooling fluid through the stator.

[0039] To optimize the cooling in the stator, a conductive stator winding is fixed on the stator body radially inwardly with respect to the longitudinal central axis, the stator winding being covered radially inwardly with a plastic injection molding of a plastic material, the stator winding protruding axially beyond the stator body on both sides with respect to the longitudinal central axis, whereby the stator body is axially flanked on both sides by annular axial protrusions.Furthermore, the stator may comprise radial cooling gaps through which a coolant can be passed, the radial cooling gaps completely penetrating one of said axial protrusions and / or another of said axial protrusions, the radial cooling gaps penetrating one of said axial protrusions and / or another of said axial protrusions practically radially with respect to the longitudinal central axis or in the direction of a vertical axis extending perpendicularly on the longitudinal central axis.

[0040] The invention may alternatively or additionally include another basic idea of ​​describing a manufacturing method for a stator or a stator body for a stator according to the above description. As part of the manufacturing method for a stator or a stator body, the following steps are provided: 1) preparing a stator body; 2) spraying, applying, coating, transfer molding or overmolding a plastic insulating or corrosion resistant material onto the outer peripheral side of the stator body, thereby sealing at least a portion of the stator body, and optionally the entire stator body, thereby realizing longitudinal ribs and / or cooling fluid guide protrusions that form longitudinal cooling passages between the longitudinal ribs.

[0041] This allows the radial cooling gaps and the plastic material cover with the cooling fluid guide protrusions to be manufactured in one process step as part of the plastic injection molding, resulting in reduced cycle times during the plastic injection molding and therefore allowing the stator as a whole to be manufactured relatively quickly and cost-effectively.

[0042] Another basic concept of the invention, which can be realized additionally or alternatively to the basic concept described above, is to describe a motor vehicle component, in particular a liquid-cooled electric drive motor, which may have a rotor interacting with a stator according to the above description, optionally manufactured by the above manufacturing method, in order to provide a drive moment on the output side. Such a motor vehicle component can be suitably used in a motor vehicle for driving the motor vehicle.

[0043] Preferably, the stator body according to a preferred embodiment has a number of reinforced (or raised) surfaces for the utilization of coolant flow, in particular realized through longitudinal ribs and / or cooling fluid guide protrusions, which are manufactured and provided by the stator overmolding process.

[0044] More preferably, in another preferred embodiment, the longitudinal cooling passage fluidly connects the first side and the second side of the stator body, in particular the first front end of the stator body and the second side of the stator body.

[0045] In another preferred embodiment, the overmolded structure, in particular realized by the longitudinal ribs and / or the cooling fluid guiding protrusions, can restrict the coolant flow solely to the outer peripheral side of the stator body, in particular in order to provide a closed chamber for cooling, for example, an electric motor, through which the cooling fluid flows preferentially in an annular manner and / or the fluid supply connections of the electric motor are preferentially located on the same side of the stator body.

[0046] In summary, it should be noted that the invention preferably relates to a stator for an electric machine having a stator body defining a longitudinal central axis, on whose outer peripheral side longitudinal ribs and longitudinal cooling passages defined by the longitudinal ribs, through which a cooling fluid can be circulated, are arranged, the stator comprising an outer housing sleeve mounted on the stator body, the stator body being practically fixed from the radially inner side to the outer housing sleeve in a frictionally coupled manner by the longitudinal ribs. The invention can additionally relate to a method for manufacturing such a stator and to an automotive component for an automotive vehicle comprising such a stator.

[0047] Further important features and advantages of the invention emerge from the dependent claims and from the drawings and the associated description of the drawings with reference to the drawings.

[0048] It is to be understood that the features mentioned above and those described below can be used not only in the respective combinations described, but also in other combinations or by themselves without departing from the scope of the invention.

[0049] Preferred exemplary embodiments of the present invention are illustrated in the drawings and will be explained in more detail in the following description, where like reference numbers refer to identical or similar or functionally identical components. [Brief description of the drawings]

[0050] [Figure 1] 1 is a perspective view showing a schematic representation of a preferred exemplary embodiment of a stator according to the present invention, in which the outer housing sleeve of the stator is hidden in order to highlight the stator body of the stator; FIG. [Diagram 2] FIG. 2 is a perspective view showing a schematic representation of another preferred exemplary embodiment of a stator according to the invention, in which the outer housing sleeve of the stator is shown and the stator is cut longitudinally for illustrative purposes only; [Diagram 3] FIG. 3 is a cross-sectional view that shows a schematic diagram of the stator according to the present invention shown in FIG. 2. [Figure 4] 5 finally shows a schematic side view of another preferred exemplary embodiment of a stator according to the invention, the outer housing sleeve of the stator being hidden in order to highlight the stator body of the stator.

[0051] 1-4 show a preferred exemplary embodiment of a stator, generally defined by reference numeral 1, which may be incorporated into an electric machine, in particular a liquid-cooled electric drive motor, and which interacts with a rotor (not shown) during operation of the electric machine.

[0052] As mentioned above, Fig. 1 shows a preferred exemplary embodiment of a stator 1, comprising an annular stator body 3 defining a central longitudinal axis 2 in a main extension direction 40 of said stator 1. The stator body 3 may for example consist of separate individual stator plates (not shown) stacked in contact with one another. A vertical axis 33 extends perpendicular to the central longitudinal axis 2, while one circumferential direction 8, indicated by an arrow corresponding to Figs. 1 and 3, rotates about the central longitudinal axis 2 and a counter circumferential direction 29, directed in the opposite direction with respect to said circumferential direction 8, indicated by an arrow corresponding to Figs. 1 and 3 as well.

[0053] Radially inward with respect to the longitudinal central axis 2, so to speak in the direction of the vertical axis 33, the stator body 3 has an inner peripheral side surface, not mentioned in more detail, on which electrically conductive stator windings 24 are fixed, completely covered by a plastic injection molding 32 of a plastic material, for example realized as part of a plastic injection molding, and at least partially covered phase supply connections 25. These covered stator windings 24 project axially beyond the stator body 3 on both sides with respect to the longitudinal central axis 2, which are called axial projections 26. In one of the two axial projections 26, radial cooling gaps 27, which can be circulated by a coolant, are arranged, which radially penetrate this axial projection 26 completely. The radial cooling gap 27, which is clearly realized on one side as a cooling slot 27a and on the other side as a cooling tunnel 27b, allows the coolant to flow radially through the axial protrusion 26, so that the coolant can, for example, cool the electric machine during operation.

[0054] Furthermore, the stator body 3 has a radially outwardly outer peripheral side surface 4 on which a number of longitudinal ribs 5 are arranged, which are formed monolithically with the stator body 3 and project radially outwardly away from the stator body 3. These longitudinal ribs 5 are spaced apart from one another in the circumferential direction 8. Here, the longitudinal ribs 5 each extend axially with respect to the longitudinal central axis 2 completely over the longitudinal length 13 of the stator body 3. In addition to this, in FIG. 1 it is also clear that the longitudinal ribs 5 each have a radially outwardly directed rib front surface 9 which is executed slightly curved about the longitudinal central axis 2. In practice, in addition to the radially outwardly directed rib front surface 9, the longitudinal ribs 5 each additionally have two rib side surfaces 11 which extend axially with respect to the longitudinal central axis 2. The rib side faces 11 face away from one another in the circumferential direction 8 and are preferably parallel or inclined relative to one another. The rib side faces 11 of the longitudinal ribs 5 can adjoin the rib front face 9 on both sides, so that the rib side faces 11 are in contact with the rib front face 9 as it were. Each longitudinal rib 5 has a transversely oriented cross section 14 with respect to the longitudinal central axis 2, which cross section 14 is configured in a substantially rectangular shape or trapezoidal, as shown in FIG. 3 .

[0055] Furthermore, the stator body 3 has a number of longitudinal cooling passages 6, through which a cooling fluid is passed during operation of the electric machine to cool the stator 1. The longitudinal cooling passages 6 are each defined or formed between two longitudinal ribs 5 which are directly adjacent to each other in the circumferential direction 8 and which exemplarily extend axially across the stator body 3. In practice, the longitudinal cooling passages 6 have the same length in the direction of the longitudinal central axis 2 as the longitudinal ribs 5. Each longitudinal cooling passage 6 has a cooling passage bottom 16 which is executed slightly curved about the longitudinal central axis 2 and which respectively recede in the radial direction with respect to the rib front surface 9 of the longitudinal rib 5. The stator body 3 is exemplarily overmolded with a plastic material, whereby the longitudinal ribs 5 and the longitudinal cooling passages 6 are completely covered by a relatively thin plastic material cover 12. The plastic material cover 12 is an exemplary integral continuous part of said plastic injection molding 32, for example as part of a plastic injection molding, realised as an integral connecting member. Each longitudinal cooling channel 6 has an exemplary empty, i.e. free, liquid-permeable channel cross-section 15 oriented transversely with respect to the longitudinal central axis 2, said free channel cross-sections 15 being formed in a substantially rectangular or trapezoidal shape. In practice, the channel cross-sections 15 of the longitudinal cooling channels 6 are at least two or three times larger in terms of area than said rib cross-sections 14 of the longitudinal ribs 5.

[0056] For example, in the mounted state of the electric machine, the stator body 3 is axially inserted or pressed into an exemplary annular outer housing sleeve 7 (see Figs. 2 and 3). The outer housing sleeve 7 thus completely surrounds the stator body 3 in the circumferential direction 8, while only surrounding the stator body 3 in a certain area in the axial direction with respect to the longitudinal central axis 2, since, merely by way of example, at least the axial projection 26 also protrudes beyond the outer housing sleeve 7. Furthermore, since the stator body 3 is inserted or pressed into the outer housing sleeve 7, the stator body 3 is frictionally fixed to the outer housing sleeve 7 from the radially inner side by the longitudinal ribs 5, so that the stator body 3 cannot rotate relative to the outer housing sleeve 7. Here, the longitudinal ribs 5 are each radially preloaded and in each case slightly curved about the longitudinal central axis 2 and bear with their radially outwardly directed rib front faces 9 against the outer housing sleeve inner circumferential side faces 10 of the outer housing sleeve 7, which are directed radially inwards towards the longitudinal central axis 2 (see Figures 2 and 3). This can be achieved such that torque can be transmitted from the stator body 3 to the outer housing sleeve 7 in a frictionally coupled manner without play and without slip. Additional torque transmission means can therefore be dispensed with.

[0057] In Figures 1 and 3, the stator body 3 has a number of cooling fluid guide projections 17 on each longitudinal rib 5, which are respectively arranged in the aforementioned longitudinal cooling passages 6, in which they interact in a flow-guiding manner with the cooling fluid flowing therethrough. Here, the cooling fluid guide projections 17 are exemplarily arranged in the respective longitudinal cooling passages 6 perpendicularly to the longitudinal ribs 5 and likewise perpendicularly to the longitudinal central axis 2. Here, the cooling fluid guide projections 17, which are exemplarily realized from plastic material as an integral part of the aforementioned plastic injection molding 32 and produced in a process step of plastic injection molding together with the stator windings 24, the phase supply connections 25 and the overmolding of the plastic material cover 12, define a cooling fluid guide projection length 20 in the respective main extension direction (see Figure 3). The cooling fluid guide protrusion lengths 20 of all the cooling fluid guide protrusions 17 are the same and are approximately 75% of the cooling passage width 21 of the longitudinal cooling passage 6 to be defined in the circumferential direction 8. Furthermore, each of the cooling fluid guide protrusions 17 has a cooling fluid guide protrusion width 22 oriented perpendicularly with respect to its cooling fluid guide protrusion length 20 (see FIG. 1). Here, the cooling fluid guide protrusion widths 22 are all the same and are approximately 25% of the cooling fluid guide protrusion length 20 of the cooling fluid guide protrusions 17. Each of the cooling fluid guide protrusions 17 is arranged on a longitudinal rib 5 (see FIG. 1). As a result, the cooling fluid guide protrusions 17 start from the respective longitudinal rib 5 on which the cooling fluid guide protrusions 17 are arranged and protrude into the longitudinal cooling passage 6 adjacent to the respective longitudinal rib 5. As a result, each longitudinal cooling passage 6 is assigned a plurality of cooling fluid guide protrusions 17. Furthermore, the cooling fluid guide protrusions 17 of each longitudinal rib 5 are arranged on the respective longitudinal rib 5 at a longitudinal distance 28 from one another in the axial direction with respect to the central longitudinal axis 2 .It is further noted in Fig. 1 that the cooling fluid guide projections 17 of each longitudinal rib 5 project axially, alternately with respect to the longitudinal central axis 2, in the circumferential direction 8 into one cooling passage 6 adjacent to the respective longitudinal rib 5 in the circumferential direction 8 and in the opposite circumferential direction 29 into another longitudinal cooling passage 6 adjacent to the respective longitudinal rib 5 in the opposite circumferential direction 29. Here, the cooling fluid guide projections 17 projecting in the circumferential direction 8 into a longitudinal cooling passage 6 are each located in a first plane 30, which plane 30 is shown in Fig. 1 simply by a dashed line in the form of a leader line, and the cooling fluid guide projections 17 projecting in the opposite circumferential direction 29 into another longitudinal cooling passage 6 are each located in a second plane 31, which plane 31 is shown in Fig. 1 simply by a dashed line in the form of a leader line. Here, the first planes 30 and the second planes 31 are obviously arranged in an alternating order in the axial direction with respect to the longitudinal central axis 2, are axially spaced apart from one another with respect to the longitudinal central axis 2 and are respectively oriented orthogonally with respect to the longitudinal central axis 2. It is also noted in FIG. 1 that one of these first planes 30 is assigned a cooling fluid guide projection 17 which protrudes in the circumferential direction 8 into the longitudinal cooling passage 6 and which is directly adjacent to one another in the circumferential direction 8. Similarly, one of these second planes 31 is assigned a cooling fluid guide projection 17 which protrudes in the opposite circumferential direction 29 into the longitudinal cooling passage 6 and which is directly adjacent to one another in the circumferential direction 8 or in the opposite circumferential direction 29.

[0058] Figure 3 shows a cross-section of the stator according to the invention shown in Figure 2, in which the stator 1 is cut in the plane A shown in dashed lines in Figure 2, so that the stator interface of the stator is visible in the direction of the arrow III, also shown in Figure 2. It should be noted here in particular that the rib front faces 9 of the longitudinal ribs 5 rest radially against the inner peripheral side surface 10 of the outer housing sleeve, and the longitudinal ribs 5 are practically radially preloaded, so that torque can be transmitted in a frictionally coupled manner from the stator body 3, in which the stator windings 24 are visible in cross section, to the outer housing sleeve 7.

[0059] Finally, Fig. 4 shows a side view of another preferred exemplary embodiment of the stator 1, the outer housing sleeve of which is hidden to show the stator body 3 of the stator 1. The stator body 3 comprises an outer peripheral side surface 4 with ribs 5 and / or cooling fluid guide projections 17 arranged on said ribs 5. Said ribs 5 and / or cooling fluid guide projections 17 extend substantially in a circumferential direction 35 around the stator body 3 and / or are inclined with respect to the longitudinal central axis 2 of the stator body 3. Thus, the stator 1 comprises a plurality of reinforced (or raised) surfaces manufactured and provided by a stator overmolding process for the exploitation of the coolant flow, in particular realized via the ribs 5 and / or the cooling fluid guide projections 17.

Claims

1. A stator (1), an annular stator body (3) defining a longitudinal central axis (2), the outer peripheral side (4) of the stator body (3) having longitudinal ribs (5) projecting radially outward and longitudinal cooling passages (6) defined by the longitudinal ribs (5) through which a cooling fluid can flow; an annular outer housing sleeve (7) fitted onto the stator body (3) in the axial direction; The stator (1), wherein the stator body (3) with the longitudinal ribs (5) is fixed to the outer housing sleeve (7) from the radially inner side in a frictionally coupled manner so as not to rotate relative to the outer housing sleeve (7), The stator (1) is configured for a liquid-cooled electric drive motor, the stator body (3) is provided with cooling fluid guide protrusions (17), the cooling fluid guide protrusions (17) are arranged in the longitudinal cooling passages (6), and in the longitudinal cooling passages (6), the cooling fluid guide protrusions (17) interact with the cooling fluid flowing therethrough in a flow-guiding manner; A plurality of cooling fluid guide protrusions (17) are respectively arranged on the longitudinal ribs (5); the cooling fluid guide protrusions (17) are arranged on each longitudinal rib (5) at a longitudinal distance (28) from one another in the axial direction relative to the longitudinal central axis (2); and The cooling fluid guide protrusions (17) of each longitudinal rib (5) extend alternately in the axial direction relative to the longitudinal central axis (2) in a circumferential direction (8) centered on the longitudinal central axis (2) into a longitudinal cooling passage (6) adjacent to the respective longitudinal rib (5) in the circumferential direction (8), and extend in a reverse circumferential direction (29) oriented oppositely relative to the circumferential direction (8) into another longitudinal cooling passage (6) adjacent to the respective longitudinal rib (5) in the reverse circumferential direction (29). A stator (1) characterized in that:

2. 2. A stator (1) according to claim 1, characterized in that the longitudinal ribs (5) are radially preloaded and abut the outer housing sleeve (7).

3. 3. The stator (1) according to claim 1 or 2, characterized in that the longitudinal ribs (5) each have a rib front surface (9) directed radially outward or slightly curved about the longitudinal central axis (2), via which the stator body (3) is supported on the inner peripheral side surface (10) of the outer housing sleeve (7).

4. The longitudinal ribs (5) are arranged on the stator body (3) spaced apart from one another in a circumferential direction (8) centered on the longitudinal central axis (2), 3. The stator (1) according to claim 1 or 2, characterized in that one longitudinal cooling passage (6) is defined between each two longitudinal ribs (5) that are immediately adjacent to each other in the circumferential direction (8).

5. 3. Stator (1) according to claim 1 or 2, characterized in that the longitudinal ribs (5) and the stator body (3) form a monolithic component.

6. 3. A stator (1) according to claim 1 or 2, characterized in that the stator body (3) is overmolded with a plastic material, by which the longitudinal ribs (5) and / or the longitudinal cooling channels (6) are realized and / or are covered at least in certain areas or completely by a plastic material cover (12).

7. the longitudinal ribs (5) extend completely across the stator body (3) in an axial direction relative to the longitudinal central axis (2); or the longitudinal ribs (5) extend axially over a maximum of 50% of the stator body (3) relative to the longitudinal central axis (2); or The longitudinal ribs (5) extend axially across a minimum of 50% and a maximum of 90% of the stator body (3) relative to the longitudinal central axis (2). A stator (1) according to claim 1, characterized in that it comprises:

8. 3. The stator (1) according to claim 1 or 2, characterized in that the cooling fluid guide protrusions (17) are respectively arranged in the longitudinal cooling passages (6) at an angle or at a right angle with respect to the longitudinal ribs (5) and / or the longitudinal central axis (2).

9. said longitudinal ribs (5) and / or said cooling fluid guiding projections (17) are realized entirely from plastic material, and / or The longitudinal ribs (5) and / or the cooling fluid guide protrusions (17) are manufactured together with the plastic material cover (12) as part of a plastic material overmolding onto the stator body (3), so that the longitudinal ribs (5) and / or the cooling fluid guide protrusions (17) and the plastic material cover (12) form a continuous, integral unit. A stator (1) according to claim 6, characterized in that it is

10. the cooling fluid guide protrusions (17) have a cooling fluid guide protrusion length (20) in their respective main extension direction, the cooling fluid guide protrusion length (20) of at least one cooling fluid guide protrusion (17) being at least 10% and / or at most 90% of the cooling passage width (21) of the cooling passage (6); and / or 3. The stator (1) according to claim 1 or 2, characterized in that the cooling fluid guide protrusions (17) have a cooling fluid guide protrusion width (22) oriented perpendicularly with respect to the cooling fluid guide protrusion length (20), and the cooling fluid guide protrusion width (22) of at least one cooling fluid guide protrusion (17) is at least 10% and / or at most 90% of the cooling fluid guide protrusion length (20) of that cooling fluid guide protrusion (17).

11. At least one cooling fluid guide protrusion (17) is arranged on each of the longitudinal ribs (5), and / or said cooling fluid guide protrusions (17) extend from the respective longitudinal ribs (5) on which they are arranged into the longitudinal cooling passages (6) adjacent to said respective longitudinal ribs (5) in such a way that at least one cooling fluid guide protrusion (17) is assigned to each longitudinal cooling passage (6); and / or The cooling fluid guide protrusions (17) that protrude into the longitudinal cooling passages (6) in the circumferential direction (8) are each located on a first plane (30), and the cooling fluid guide protrusions (17) that protrude into other longitudinal cooling passages (6) in the opposite circumferential direction (29) are each located on a second plane (31), the first planes (30) and the second planes (31) are arranged in an alternating order in the axial direction with respect to the longitudinal central axis (2) and are spaced apart from each other in the axial direction with respect to the longitudinal central axis (2), and the first 3. The stator (1) according to claim 1 or 2, characterized in that the cooling fluid guide protrusions (17) that are immediately adjacent to one another in the circumferential direction (8) and that extend into the longitudinal cooling passages (6) in the circumferential direction (8) are assigned to one first plane (30) of the planes (30), and the cooling fluid guide protrusions (17) that are immediately adjacent to one another in the opposite circumferential direction (29) and that extend into the longitudinal cooling passages (6) in the opposite circumferential direction (29) are assigned to one second plane (31).

12. A conductive stator winding (24) covered by a plastic injection molding (32) is fixed on the stator body (3) radially inward with respect to the longitudinal central axis (2), and the stator winding (24) protrudes axially beyond the stator body (3) on both sides with respect to the longitudinal central axis (2), so that the stator body (3) has annular axial protrusions (26) arranged axially on both sides thereof; the stator (1) comprises radial cooling gaps (27) through which a coolant can flow, the radial cooling gaps (27) passing through one and / or another of the axial projections (26); and / or 3. The stator (1) according to claim 1 or 2, characterized in that the radial cooling gaps (27) penetrate one and / or another of the axial projections (26) in a radial direction with respect to the longitudinal central axis (2) or in the direction of a vertical axis (33) extending perpendicularly on the longitudinal central axis (2).

13. A method for manufacturing a stator (1) according to claim 1, comprising the steps of: (1) preparing a stator body (3); (2) spraying, painting, coating, transfer molding or overmolding a plastic insulating or corrosion-resistant material onto the outer peripheral side surface (4) of the stator body (3), thereby sealing at least a portion of the stator body (3), and optionally the entire stator body, thereby realizing the longitudinal ribs (5) and cooling fluid guide protrusions (17) that form longitudinal cooling passages (6) between the longitudinal ribs (5); A method for producing a compound comprising the steps of:

14. 14. A motor vehicle component, namely a liquid-cooled electric drive motor, having a rotor interacting with a stator (1) according to claim 1, manufactured by the method according to claim 13, to provide a drive torque on the output side.

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