Stator of an electric machine with slotted locking sleeve

Abstract

The present invention relates to a stator (1) of an electric machine (10), the stator (1) comprising: a stator body (2) extending annularly around a stator axis (100), the stator body (2) having a plurality of stator teeth (3) and stator grooves (4) formed between the stator teeth (3), and a groove closure sleeve (5), in particular a slotted tube, which is designed for radially closing the stator grooves (4) and has at least one sleeve strip (6) along a sleeve circumference (5a) extending annularly or partially annularly around the stator axis (100) and forming at least one sleeve slot (5b) extending in the axial direction (200) with respect to the stator axis (100) at at least one joint of two strip ends (6a), characterized in thatthat at least one positive locking element (7) is provided at or between two adjacent strip ends (6a) of the at least one sleeve strip (6) for positive locking or clamping of the two adjacent strip ends (6a) to the stator body (2).

Description

State of the art The present invention relates to a stator of an electric machine. The invention also relates to an electric machine comprising such a stator. The stator particularly includes a slot closure sleeve that covers the stator slots. Electrical machines are known from the prior art. These machines, for example, have a stator with a stator winding. It is also known that the stator is sealed or covered radially inwards by a stator sleeve. For example, DE 10 2021 104 824 A1 discloses a stator that has a stator sleeve which seals or covers the stator slots radially inwards. The document also discloses a variant in which the stator sleeve has an axially extending slot filled with adhesive to fix the stator sleeve to a stator tooth. Disclosure of the invention The stator according to the invention has a slot closure sleeve as a slot closure, which enables simple and reliable closing of the stator slots. Optimal clamping of the slot closure sleeve against the stator body is always achieved. The stator of an electric machine comprises a stator body and a slot closure sleeve. The stator body extends in a ring shape around a stator axis. The stator body has a plurality of stator teeth and stator slots formed between the stator teeth. With respect to the stator axis, an axial direction, oriented along the stator axis, and a radial direction, oriented perpendicular to the stator axis, are defined. The slot closure sleeve is, in particular, a slotted tube. The slot closure sleeve is designed for radially closing the stator slots and has at least one sleeve strip along its circumference. The sleeve strip extends in an annular or partially annular shape around the stator axis. At at least one joint between two strip ends, the sleeve strip forms at least one sleeve slot extending axially with respect to the stator axis. At least one positive locking element is provided at or between two adjacent strip ends of the at least one sleeve strip. The positive locking element is designed to positively lock or clamp the two adjacent strip ends to the stator body. The slot closure sleeve is designed to reliably close the stator slots. Furthermore, the positive locking element allows the slot closure sleeve to be clamped or secured. The slot closure sleeve can be easily and cost-effectively assembled and manufactured, ensuring a reliable slot closure. The dependent claims describe preferred embodiments of the invention. The respective positive locking element preferably engages in a fastening groove at the end of a stator tooth or in a slot of a stator groove. This ensures that the positive locking element is reliably held in the fastening groove or slot. The sleeve strip can thus be reliably pre-tensioned. Preferably, the stator has two positive locking elements, one at each adjacent strip end. The two positive locking elements from two adjacent strip ends preferably engage in pairs in a fastening groove at the end of a stator tooth or in pairs in a slot within a stator groove. Alternatively, and more preferably, the two positive locking elements from two adjacent strip ends engage separately in two different fastening grooves at the ends of two stator teeth. Another alternatively, and more preferably, the two positive locking elements from two adjacent strip ends engage separately in a fastening groove and a slot. The positive locking elements allow for a flexible fastening method, ensuring optimal attachment of the sleeve strip in all cases. The respective positive locking element preferably has a positive locking contour for engaging in the fastening groove or slot. The positive locking contour is particularly hook-shaped or includes a thickening or an undercut. This ensures a positive locking connection and reduces the risk of the sleeve strip or the slot closure sleeve coming loose. The respective interlocking element is formed in one piece at the respective strip end. In particular, the interlocking element is molded or formed. Thermally formed interlocking elements are especially advantageous. Alternatively, the interlocking element is injection-molded. Due to its one-piece design, the interlocking element is formed directly at the strip end. This allows for simple production of the sleeve strip. It is also preferred that the respective positive locking element is attached as a separate part to one or both ends of the strip. This allows the sleeve strip and the positive locking element to be manufactured separately, thus simplifying the individual manufacturing processes. In particular, the shape of the positive locking element can be easily and cost-effectively adapted to the specific fastening application. Furthermore, different materials can be provided in this way to optimally adapt the positive locking element and the sleeve strip to the desired application. The respective positive locking element advantageously extends along a butt edge of the respective strip end. In particular, the positive locking element extends over the full length or partial length of the butt edge. Thus, the positive locking element is present over a complete axial extension or over a partial axial extension of the strip end. This allows a fixing force and / or clamping force to be preferably applied to the sleeve strip over this extension. The slotted sleeve preferably has a single sleeve strip to form a slotted sleeve. In an alternative embodiment, the slotted sleeve has several sleeve strips to form a segmented sleeve. Different sleeve properties can thus be achieved by varying the number of sleeve strips. In all cases, the respective positive locking elements ensure that the slotted sleeve is reliably held on the stator body and optimally clamped. Preferably, an axially extending, rod-shaped intermediate element can be inserted between two positive-locking elements of two adjacent strip ends. This intermediate element serves to clamp the adjacent strip ends against the tooth ends of a slot. This allows the slot closure sleeve to be fixed and, preferably, pre-tensioned. The intermediate element is particularly preferably mounted in one or two end plates of the stator body. The intermediate element therefore allows for easy pre-tensioning and / or fixing, as well as easy release of the pre-tension and / or fixing of the slot closure sleeve. The intermediate element preferably has a cross-section, particularly oval, with at least two different radial extensions. Specifically, the intermediate element is a spreading element rotatable about a rod axis. Rotating the intermediate element about the rod axis allows for a clamping position and a release position. For clamping, a larger radial extension of the intermediate element is positioned between the two positive-locking elements; for releasing, the smaller radial extension is positioned between the positive-locking elements. This simplifies stator assembly, and in particular, stator disassembly is also simple and requires minimal effort. Rotation of the intermediate element is prevented, in particular, by the stator end plate, thus avoiding unintentional twisting. The intermediate element and the slot closure sleeve are therefore reliably held to the stator body. The fixing groove or slot has a mating contour for positive locking interaction with the respective locking element. This mating contour features an undercut and / or is designed to correspond to the locking contour of the respective locking element. This allows for secure fixation in the radial direction, ensuring reliable retention of the locking sleeve. In a preferred embodiment, two adjacent strip ends are welded together by forming a weld seam. The weld seam preferably projects positively into the mounting groove or slot. Thus, the weld seam serves both to fasten the strip ends to each other and to form a positive connection with the stator body, thereby holding the slot closure sleeve to the stator body and clamping the slot closure sleeve. The respective positive locking element is advantageously arranged as a separate part between two strip ends. Furthermore, the positive locking element preferably clamps the strip ends against the stator body in opposite circumferential directions. This ensures that the slot closure sleeve is firmly held and clamped to the stator body, while also allowing for easy release of the clamping and retention if necessary. The invention also relates to an electric machine. The electric machine has a stator as described above and a rotor. The rotor interacts with the stator, the stator being designed to drive the rotor. The electric machine is, for example, a permanent magnet synchronous machine. Brief description of the drawings Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawings. The drawing shows: Fig. 1 a schematic representation of an electric machine according to an exemplary embodiment of the invention, Fig. 2 a schematic view of a slot closure sleeve of the stator of the electric machine according to the exemplary embodiment of the invention, Fig. 3 a schematic view of a slot closure sleeve of the electric machine mounted on the stator body according to the exemplary embodiment of the invention, Fig. 4 a schematic view of a first variant of the slot closure sleeve of the electric machine according to the exemplary embodiment of the invention, Fig. 5 a schematic view of a second variant of the slot closure sleeve of the electric machine according to the exemplary embodiment of the invention.Fig. 6 a first schematic view of a third variant of the slot closure sleeve of the electric machine according to the embodiment of the invention, Fig. 7 a second schematic view of a third variant of the slot closure sleeve of the electric machine according to the embodiment of the invention, Fig. 8 a schematic illustration of a stator of the electric machine according to the embodiment of the invention with a fourth variant of the slot closure sleeve, Fig. 9 a schematic view of an exemplary manufacture of the embodiment as shown in Fig. 8, Fig. 10 a schematic illustration of a stator of the electric machine according to the embodiment of the invention with a fifth variant of the slot closure sleeve, Fig. 11 a schematic illustration of a stator of the electric machine according to the embodiment of the invention with a sixth variant of the slot closure sleeve, and Fig.12 a schematic illustration of a stator of the electrical machine according to the embodiment of the invention with a seventh variant of the slot closure sleeve. Embodiments of the invention Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals. Fig. 1 schematically shows an electric machine 1 according to an embodiment of the invention. The electric machine 1 has a stator 1 and a rotor 11, wherein the rotor 11 can be driven by the stator 1. The stator 1 has a stator body 2, wherein a slotted sleeve 5 is attached to the stator body 2. The slotted sleeve 5 is, in particular, a slotted tube. The stator body 2 and the stator 1 extend in a ring shape around a stator axis 100. The stator axis 100 is preferably also a rotational axis of the rotor 11 and preferably a central axis of the electric machine 10. An axial direction 200 is defined with respect to the stator axis 100, which is aligned parallel to the stator axis 100. In addition, a radial direction 300 is defined perpendicular to the stator axis 100 and thus perpendicular to the axial direction 200. A circumferential direction 400 (see Fig. 2) extends circumferentially around the stator axis 100. Fig. 2 schematically shows a view of the slot closure sleeve 5. The slot closure sleeve 5 is arranged within the stator body 2 and thus between the stator body 2 and the rotor 11, and has at least one sleeve strip 6 along a sleeve circumference 5a, which extends annularly or partially annularly around the stator axis 100. The slot closure sleeve 5 forms at least one sleeve slot 5b at at least one joint of two strip ends 6a, extending in the axial direction 200 with respect to the stator axis 100. In the embodiment shown, the slot closure sleeve 5 has a single sleeve strip 6 to form a slotted sleeve. Fig. 3 schematically shows a section of a stator 1, wherein the stator body 2 has a plurality of stator teeth 3 and stator slots 4 formed between the stator teeth 3. An electrical winding (not shown) can be inserted between the stator teeth 3, with the wires of the winding arranged within the stator slots 4. The slot closure sleeve 5 is designed for radially closing the stator slots 4. At least one positive locking element 7 is provided at or between two adjacent strip ends 6a of the at least one sleeve strip 6 of the groove closure sleeve 5. The positive locking element 7 serves to positively lock or clamp the two adjacent strip ends 6a to the stator body 2. For this purpose, the respective positive locking element 7 engages in a fastening groove 8 of a tooth end 3a of a stator tooth 3. In the illustrated embodiment, it is provided that two positive locking elements 7 from two adjacent strip ends 6a engage in pairs in a fastening groove 8 of a tooth end 3a of a stator tooth 3. The respective positive locking element 7 has a positive locking contour for engaging in the fastening groove 8 or the slot 9. The positive locking contour includes, in particular, a hook-shaped section, a thickening, or an undercut. The fastening groove 8 has a counter-positive locking contour 7a for positive locking interaction with the respective positive locking element 7. In the example shown, the counter-positive locking contour 7a has an undercut and is, in particular, designed to correspond to the positive locking contour of the respective positive locking element 7. Thus, fixation in the radial direction 300 is achieved by positive locking. Fig. 4 schematically shows a first variant of the groove closure sleeve 5. In this case, the respective positive locking element 7 is formed integrally at the respective strip end 6a. The positive locking element 7 can be formed in various ways, for example, by molding, forming, or injection molding. In the case of forming, thermal forming is particularly advantageous. A second variant of the groove closure sleeve 5 is shown schematically in Fig. 5. In this variant, the respective positive locking element 7 is formed as a separate part. The separate positive locking element 7 is attached to one strip end 6a or to two strip ends 6a. In both variants as shown in Fig. 4 and Fig. 5, the respective positive locking element 7 extends along a butt edge 6b of the respective strip end 6a, in particular over a full length or partial length of the butt edge 6b. The butt edge 6b runs in particular along the axial direction 200. Figures 6 and 7 schematically show a third alternative of the slot closure sleeve 5. In this embodiment, the respective positive locking element 7 engages in a slot 9 of a stator slot 4. Specifically, two positive locking elements 7 from two adjacent strip ends 6a engage in pairs in a slot 9 of a stator slot 4. An axially extending rod-shaped intermediate element 12 is inserted between two positive-locking elements 7 of two adjacent strip ends 6a. The intermediate element is designed to clamp the adjacent strip ends 6a against the tooth ends 3a of a slot 9. For this purpose, the intermediate element 12 has an oval cross-section with at least two different radial extensions 12a, 12b. Furthermore, the intermediate element is a spreading element rotatable about a rod axis 500. Thus, the intermediate element 12 can be rotated between a clamping and a releasing position. Figure 6 shows a released position, and Figure 7 a clamping position. To achieve the releasing position, the larger radial extension 12a is oriented radially 300, so that the smaller radial extension 12b is located between the strip ends 6a. This results in no clamping force being applied to the strip ends 6a. If, however, the larger radial extension 12b is located between the strip ends 6a, this leads to a tensioning of the strip ends 6a. In this orientation, the smaller radial extension 12b is oriented along the radial direction 300. Fig. 8 shows a fourth variant of the slot closure sleeve 5 of the electric machine 10, and Fig. 9 shows an exemplary sequence of a manufacturing process. In this case, the slot closure sleeve 5 has several sleeve strips 6 to form a segmented sleeve. Three sleeve strips 6 of equal size are shown here as an example, which are pressed against a tool 13. For example, the sleeve strips 6 are held against the tool 13 by means of a vacuum and inserted into the stator body 2, where opposite strip ends 6a are clamped by means of an intermediate element 12. For this purpose, the strip ends 6a are clamped by the intermediate element 12 against the tooth ends 3a of the slot 9. The segmented sleeve produced in this way is clamped multiple times against the stator body 2 and is thus optimally held or clamped. Fig. 10 schematically shows a stator 1 of the electric machine 10 with a slot closure sleeve 5 according to a fifth variant. The slot closure element 5 has formed positive locking elements 7 at each of the strip ends 6a, wherein the positive locking elements 7 engage in a slot 9. The positive locking elements 7 form a positive locking connection with mating positive locking contours 7a of the slot 8 for holding and / or clamping the slot closure sleeve 5. Fig. 11 schematically shows a stator 1 of the electric machine 10 with a slot-locking sleeve 5 according to a sixth variant. In this case, the respective positive locking element 7 is arranged as a separate part between two strip ends 6a. The positive locking element 7 clamps the strip ends 6a in opposite circumferential directions 400 against the stator body 2. For this purpose, the positive locking element 7 is arranged in a slot 9. Fig. 12 schematically shows a stator 1 of the electric machine 10 with a slot closure sleeve 5 according to a seventh variant. In this case, a combination of the variant from Fig. 10 and the intermediate element 12 is shown. On the one hand, the strip ends 6a each have a positive locking element 7 to form a positive lock with a counter-positive locking contour 7a of the slot 9. On the other hand, the strip ends 6a are pressed against the tooth ends 3a of the slot 9 by an intermediate element 12. Thus, a reliable preload and optimal retention of the slot closure sleeve 5 are achieved. In other variants, two positive locking elements 7 from two adjacent strip ends 6a engage separately in two different fastening grooves 8 in the tooth ends 3a of two stator teeth 3, or separately in a fastening groove 8 and a slot 9. In a further variant, two adjacent strip ends 6a can be welded together, forming a weld seam. This weld seam protrudes positively into the fastening groove 8 or the slot 9, thereby allowing the locking sleeve 5 to be held and / or clamped. QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 10 2021 104 824 A1

[0002]

Claims

Stator (1) of an electric machine (10), the stator (1) comprising: • a stator body (2) extending annularly around a stator axis (100), wherein the stator body (2) has a plurality of stator teeth (3) and stator slots (4) formed between the stator teeth (3), and • a slot closure sleeve (5), in particular a slot tube, which is designed for radially closing the stator slots (4) and has at least one sleeve strip (6) along a sleeve circumference (5a) extending annularly or partially annularly around the stator axis (100) and forming at least one sleeve slot (5b) extending in the axial direction (200) with respect to the stator axis (100) at at least one joint of two strip ends (6a), characterized in thatthat at least one positive locking element (7) is provided at or between two adjacent strip ends (6a) of the at least one sleeve strip (6) for positive locking or clamping of the two adjacent strip ends (6a) to the stator body (2). Stator (1) according to claim 1, characterized in that the respective positive locking element (7) engages in a fastening groove (8) of a tooth end (3a) of a stator tooth (3) or in a slot (9) of a stator groove (4). Stator (1) according to one of the preceding claims, characterized in that two positive locking elements (7) of two adjacent strip ends (6a) engage • in pairs in a fastening groove (8) of a tooth end (3a) of a stator tooth (3) or • in pairs in a slot (9) of a stator groove (4) or • separately from one another in two different fastening grooves (8) in tooth ends (3a) of two stator teeth (3) or • separately from one another in a fastening groove (8) and a slot (9). Stator (1) according to one of the preceding claims, characterized in that the respective positive locking element (7) for engaging in the fastening groove (8) or in the slot (9) has a positive locking contour which is in particular hook-shaped or comprises a thickening or an undercut. Stator (1) according to one of the preceding claims, characterized in that the respective form-locking element (7) is formed in one piece at the respective strip end (6a), in particular by forming or deforming, especially by thermal deforming, or by injection molding. Stator (1) according to one of the preceding claims, characterized in that the respective positive locking element (7) is attached as a separate part to one strip end (6a) or to two strip ends (6a). Stator (1) according to one of the preceding claims, characterized in that the respective positive locking element (7) extends along a butt edge (6b) of the respective strip end (6a), in particular over a full length or partial length of the butt edge (6b). Stator (1) according to one of the preceding claims, characterized in that the slot closure sleeve (5) has a single sleeve strip (6) to form a slotted sleeve or several sleeve strips (6) to form a segmented sleeve. Stator (1) according to one of the preceding claims, characterized in that a rod-shaped intermediate element (12) extending in the axial direction (100) can be inserted between two positive locking elements (7) of two adjacent strip ends (6a) for clamping the adjacent strip ends (6a) against the tooth ends (3a) of a slot (9). Stator (1) according to claim 9, characterized in that the intermediate element (12) has a particularly oval cross-section with at least two different radial extensions (12a, 12b) and is in particular a spreading element rotatable about a rod axis (500). Stator (1) according to one of the preceding claims, characterized in that the fastening groove (8) or the slot (9) has a counter-form-locking contour (7a) for positive-locking interaction with the respective positive-locking element (7), which in particular includes an undercut and / or is designed in particular corresponding to the positive-locking contour of the respective positive-locking element (7). Stator (1) according to one of the preceding claims, characterized in that two adjacent strip ends (6a) are welded together forming a weld seam which protrudes into the fastening groove (8) or the slot (9) in a form-fitting manner. Stator (1) according to one of the preceding claims, characterized in that the respective positive locking element (7) is arranged as a separate part between two strip ends (6a) and clamps the strip ends (6a) in opposite circumferential direction (400) against the stator body (2). Electric machine (1) comprising a stator (1) according to one of the preceding claims, and a rotor (11) which can be driven by the stator.

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