Stator of an electric machine
Patent Information
- Application Number
- EP2024704144
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-03-06
- Filing Date
- 2024-02-07
- Publication Date
- 2026-01-14
AI Technical Summary
Existing stator designs for electrical machines face challenges in efficient cooling, requiring complex and costly cooling channels in the stator housing, which increases manufacturing costs and reduces cooling effectiveness.
The stator design incorporates a supply path within the laminated core that directs cooling medium to both slot and yoke channels, providing direct conductor cooling and jacket cooling of the stator yoke, eliminating the need for complex housing channels and enhancing uniform cooling across the stator yoke.
This design improves cooling efficiency, reduces manufacturing costs, and ensures uniform cooling of the stator yoke, while simplifying the cooling path and reducing pressure loss, thus enhancing the overall performance and cost-effectiveness of the electrical machine.
Smart Images
Figure EP2024052985_12092024_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] title
[0003] Stator of an electrical machine
[0004] State of the art
[0005] The invention is based on a stator of an electrical machine according to the preamble of the main claim.
[0006] A stator of an electrical machine is already known from DE102019113785 A1, having a stator axis and a stator laminated core on which stator teeth and stator slots located between the stator teeth are formed and which comprises a stator yoke connecting the stator teeth, wherein the stator slots extend in the radial direction with respect to the stator axis between a slot base and a slot head, wherein a single conductor or a conductor bundle comprising several conductors, in particular a stack of flat wire conductors, is provided in each of the stator slots to form an electrical stator winding, wherein at least one slot gap is provided between the slot flanks of the respective stator slot and the conductor or conductor bundle arranged in the stator slot, which forms a slot gap channel extending in the axial direction for direct conductor cooling, through which a cooling medium can flow along a slot cooling path.
[0007] Advantages of the invention
[0008] The stator of an electrical machine according to the invention with the characterizing features of the main claim has the advantage that the cooling of the stator is further improved. Furthermore, in addition to the direct conductor cooling, jacket cooling of the stator yoke can be provided. Since the cooling medium is supplied directly through the stator yoke, complex and expensive cooling channels in a stator housing surrounding the stator can be eliminated. The manufacturing costs are thus reduced. This is achieved according to the invention in that
[0009] - at least one supply path is formed in the stator core, which is
[0010] Cooling medium supply of at least one slot cooling path opens into at least one of the stator slots,
[0011] - the respective supply path opens into a slot inlet of the respective stator slot with a radial channel and comprises at least one yoke channel upstream of the radial channel, which runs in the axial direction in the stator yoke and is provided for cooling the stator yoke
[0012] The measures listed in the subclaims enable advantageous further developments and improvements of the stator of an electrical machine specified in the main claim.
[0013] It is particularly advantageous if several yoke channels of at least one supply path are distributed over the circumference of the stator yoke and form a jacket cooling system for the stator yoke. This ensures uniform cooling of the stator yoke across the circumference of the stator yoke.
[0014] It is further advantageous if, according to a first embodiment, several of the yoke channels are through-channels that each completely pass through the stator core in the axial direction and each have at least one entrance into the respective radial channel, which is provided in particular in the region of the axial center or in the axial center of the through-channel. In this way, the stator yoke is continuously flowed through in the axial direction, thus achieving uniform cooling of the stator yoke along the axial direction.
[0015] It is very advantageous if, according to a second embodiment, several of the yoke channels are short channels that extend from at least one of the two end faces of the stator laminated core in the axial direction to the entrance into the respective radial channel and are shorter than a through channel, in particular extending into an axial central region of the stator laminated core. In a first variant of the second embodiment, in which only short channels are provided that extend exclusively from one of the two end faces of the stator laminated core, partial jacket cooling of the stator yoke is achieved, which only encloses an axial part of the stator yoke. This first variant is particularly simple and cost-effective to implement.In a second variant of the second embodiment, in which short channels are provided that extend from both end faces of the stator core, a full-wall cooling of the stator yoke can be achieved, essentially enclosing the entire stator yoke. However, the second variant of the second embodiment requires a cooling medium supply from both end faces of the stator core.
[0016] It is also advantageous if, according to a third exemplary embodiment, several pairs of yoke channels are provided and distributed over the circumference of the stator yoke, wherein the yoke channels of each pair extend from the same end face of the stator laminated core and are adjacent when viewed in the circumferential direction, wherein one of the yoke channels of each pair is a short channel and the other of the yoke channels is a meander channel, wherein the respective meander channel comprises a through section, a deflection section and a short section, wherein for each pair of yoke channels, the short channel and the short section of the meander channel are arranged opposite one another in pairs, in particular in the same circumferential position.
[0017] In this way, a full jacket cooling of the stator yoke is essentially achieved, which essentially encloses the entire stator yoke, but advantageously only requires a cooling medium supply from one of the two end faces of the stator laminated core.
[0018] Furthermore, it is advantageous if the deflection section of the meander channel according to the third embodiment is formed in the stator core or in a deflection device arranged on the end face of the stator core. This allows the deflection of the meander channel to be achieved in a simple manner. The deflection device can, for example, be annular or disc-shaped and encompass the deflection sections of all meander channels.
[0019] Furthermore, it is advantageous if an annular distribution channel is arranged on at least one of the two end faces of the stator laminated core, which opens into the yoke channels and is provided for supplying the supply paths with cooling medium. The distribution channel distributes the cooling medium in the circumferential direction to the yoke channels distributed over the circumference. This makes it possible to easily supply the supply paths with cooling medium. It is advantageous if two slot cooling paths running in opposite directions are provided in the respective stator slot, which exit as a free jet at the ends of the respective stator slot via a slot outlet, in particular in the slot head or the slot base. In this way, the cooling path in the stator is simplified with regard to the flow connection of the slot gap channels or the slot cooling paths.In particular, no annular collector is required on the end faces of the stator core to collect the cooling medium escaping from the slot gap channels, which would require sealing a stator chamber from a rotor chamber of the electric machine, for example, using a sleeve or a can. Furthermore, the flow connection of the slot gap channels according to the invention enables lower pressure in the cooling path, thus reducing the requirements for sealing the slot gap channels. Furthermore, the pressure loss in the respective cooling path is reduced because the respective cooling path does not run over the entire length, but only over an axial section of the respective stator slot.
[0020] According to an advantageous embodiment, the radial channel of the respective supply path is formed by a punched-out or recess in a single lamination of the stator core or by several radial channel sections that are radially offset in several adjacent laminations and partially overlap in the radial direction. This allows the radial channel to be created in the stator core in a simple and cost-effective manner.
[0021] It is further advantageous if several support points are formed in the stator slots, spaced apart from one another in the axial direction relative to the stator axis, for clamping the conductor or conductor bundle located in the respective stator slot. The support points are each formed by twisting individual or multiple laminations of the stator core, in particular a group or multiple groups of laminations. In this way, the support points can be created without special laminations, and the conductor bundles can be inserted into the stator slots during assembly without clamping forces. This reduces the manufacturing costs of the stator. Furthermore, damage to the conductor bundles when inserting the conductor bundles into the respective stator slots is avoided. Drawing
[0022] Several embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.
[0023] They show:
[0024] Fig.1 is a side view of part of the stator according to the invention,
[0025] Fig.2A is a sectional view of the stator according to the invention according to a first embodiment in a section of the stator along the line II-II in Fig.1,
[0026] Fig.2B shows several of the yoke channels of the stator according to the invention according to Fig.1 according to the first embodiment according to Fig.2A in a linear development view,
[0027] Fig.3A is a sectional view of the stator according to the invention according to a second embodiment in a section of the stator along the line II-II in Fig.1,
[0028] Fig.3B shows several of the yoke channels of the stator according to the invention according to Fig.1 according to the second embodiment according to Fig.3A in a linear development view,
[0029] Fig.4A shows several of the yoke channels of the stator according to the invention according to Fig.1 according to a third embodiment in a linear development representation,
[0030] Fig.4B is a first sectional view of the stator according to the invention according to the third embodiment of Fig.4A, with a section of the stator along the line IV-IV in Fig.4A,
[0031] Fig.4C is a second sectional view of the stator according to the invention according to the third embodiment of Fig.4A, with a section of the stator along the line VV in Fig.4A,
[0032] Fig.5A shows an embodiment of a first lamination with channel sections for creating radial channels in the stator lamination stack,
[0033] Fig.5B shows an embodiment of a second lamination with channel sections for creating radial channels in the stator lamination stack,
[0034] Fig.5C shows an arrangement of the first and second laminations according to Fig.5A and 5B for generating the radial channels in the stator lamination stack,
[0035] Fig.6 shows a groove cross-section along the line Vl-Vl in Fig.2A, Fig.7 shows a groove cross-section along the line Vll-Vll in Fig.2A,
[0036] Fig.8 shows a groove cross-section along the line VIII-VIII in Fig.2A,
[0037] Fig.9 shows in section one of the stator slots of the stator according to the invention with a conductor bundle mounted at several support points and
[0038] Fig.10 is a partial view of the stator according to the invention with twisted laminations for creating support points for the conductor bundles.
[0039] Description of the embodiments
[0040] Fig.1 shows a side view of part of the stator according to the invention.
[0041] The stator 1 of an electrical machine 2 according to the invention has a stator axis 3 and a stator core 4, on which stator teeth 5 and stator slots 6 located between the stator teeth 5 are formed, and which comprises a stator yoke 7 connecting the stator teeth 5. The stator slots 6 extend in the radial direction with respect to the stator axis 3 between a slot base 6g and a slot head 6h and can each have a slot 6s in the slot head 6h.
[0042] In each of the stator slots 6, a single electrical conductor 8 or a conductor bundle 9 comprising several conductors 8, in particular a stack of flat wire conductors, is provided to form an electrical stator winding 10.
[0043] Between the slot flanks 6f of the respective stator slot 6 and the conductor 8 or conductor bundle 9 arranged in the stator slot 6, at least one slot gap 12 is provided, which forms a slot gap channel 13 extending in the axial direction with respect to the stator axis 3, through which a cooling medium can flow along a slot cooling path 14.
[0044] Fig.2A shows a sectional view of the stator according to the invention according to a first embodiment with a section of the stator along the line II-II in Fig.1.
[0045] The stator laminated core 4 is formed by a stack of laminated laminations 16.
[0046] In the respective stator slot 6, two slot cooling paths 14 are provided which run in opposite directions and exit as a free jet at the ends of the respective stator slot 6 via a slot outlet 14.2, in particular in the slot head 6h or in the slot base 6g. The stator slots 6 can be closed by means of at least one slot closure 19 to seal the slot cooling paths 14. The slot closure can be produced, for example, as shown in Fig. 1 and Fig. 6 to Fig. 8, by designing a single sleeve- or tubular slot closure as a separate element for closing all of the slot slots 6s. According to a second variant (not shown), a strip-shaped slot closure, in particular a cover slide, can be provided as a separate element in each slot slot 6s.According to a third variant not shown, the slot closures 19 can each be formed by tooth tip bridges which are part of the laminations 16, connect tooth tips of adjacent stator teeth 5 and in particular have a reduced magnetic conductivity.
[0047] According to the invention, at least one supply path 15 is formed in the stator laminated core 4, which opens into at least one of the stator slots 6 for supplying cooling medium to at least one slot cooling path 14.
[0048] Furthermore, it is provided according to the invention that the respective supply path 15 opens into a groove inlet 14.1 of the respective stator groove 6 with a radial channel 15.1 running in the radial direction and comprises at least one yoke channel 15.2 upstream of the radial channel 15.1, which runs in the axial direction in the stator yoke 7 and is provided for cooling the stator yoke 7.
[0049] Fig.2B shows several of the yoke channels of the stator according to the invention according to Fig.1 according to the first embodiment according to Fig.2A in a linear development representation.
[0050] For example, several yoke channels 15.2 of the at least one supply path 15 are distributed over the circumference of the stator yoke 7 and in this way form a jacket cooling in the stator yoke 7.
[0051] According to a first exemplary embodiment, several of the yoke channels 15.2 are designed as through-channels 23, each of which completely passes through the stator core 4 in the axial direction and each has at least one inlet 17 into the respective radial channel 15.1. The inlet 17 is provided, for example, in the region of the axial center of the through-channel 23, in particular in the axial center. An annular distribution channel 20 can be arranged on each of the two end faces of the stator core 4, which opens into the respective yoke channels 15.2 and is provided for supplying the supply paths 15 with cooling medium.
[0052] Fig.3A shows a sectional view of the stator according to the invention according to a second embodiment in a section of the stator along the line II-II in Fig.1. Fig.3B shows several of the yoke channels of the stator according to the invention according to Fig.1 according to the second embodiment according to Fig.3A in a linear development representation.
[0053] According to the second embodiment, several of the yoke channels 15.2 are designed as short channels 24, which extend from at least one of the two end faces of the stator laminated core 4 in the axial direction to the entrance into the respective radial channel and are shorter than a through channel 23, in particular extending into an axial central region of the stator laminated core 4.
[0054] According to a first variant of the second exemplary embodiment (not shown), only short channels 24 can be provided, which run exclusively from one of the two end faces of the stator laminated core 4 and thus achieve partial jacket cooling that only encloses an axial part of the stator yoke 7. According to a second variant of the second exemplary embodiment, shown in Fig. 3A and Fig. 3B, short channels 24 can also be provided, which run from both end faces of the stator laminated core 4. This second variant achieves full jacket cooling that essentially encloses the entire stator yoke 7. For the second variant, an annular distribution channel 20 can be provided on each of the two end faces of the stator laminated core 4, which opens into the respective yoke channels 15.2 and is intended to supply the supply paths 15 with cooling medium.
[0055] The short channels 24 extending from one end face of the stator core 4 and the short channels 24 extending from the other end face are aligned in pairs with respect to each other, for example, with respect to their circumferential position, in particular arranged opposite each other or in pairs in the same circumferential position. Fig. 4A shows several of the yoke channels of the stator according to the invention shown in Fig. 1 according to a third embodiment in a linear development view. Fig. 4B shows a first sectional view of the stator according to the invention according to the third embodiment shown in Fig. 4A, with a section of the stator along the line
[0056] IV-IV in Fig.4A.
[0057] Fig.4C shows a second sectional view of the stator according to the invention according to the third embodiment of Fig.4A with a section of the stator along the line
[0058] VV in Fig.4A.
[0059] According to the third embodiment, several pairs 15.2p of yoke channels 15.2 of different lengths are provided and distributed over the circumference of the stator yoke 7. The yoke channels 15.2 of each pair 15.2p extend from the same end face of the stator laminated core 4 and are adjacent to one another in the circumferential direction, wherein one of the yoke channels 15.2 of each pair 15.2p is a short channel 24 and the other of the yoke channels 15.2 of the same pair 15.2p is a meander channel 25, which comprises a through section 25.1, a deflection section 25.2 and a short section 25.3. On the front side of the stator laminated core 4, from which the yoke channels 15.2 originate, an annular distribution channel 20 can be arranged, which opens into the respective yoke channels 15.2 and is provided for supplying the supply paths 15 with cooling medium.
[0060] For each pair 15.2p of yoke channels 15.2, the short channel 24 and the short section 25.3 of the meander channel 25 are arranged in pairs opposite each other, in particular in the same circumferential position.
[0061] In this way, the third embodiment achieves a full jacket cooling that essentially encloses the entire stator yoke 7.
[0062] The deflection sections 25.2 of the meander channels 25 can be formed, according to Fig. 4A, in a deflection device 26 arranged on the end face of the stator core 4 or, in a manner not shown, in the stator core 4. The deflection device 26 can, for example, be annular or disc-shaped and comprise the deflection sections of all meander channels.
[0063] Fig. 5A shows a design of a first lamination with channel sections for creating radial channels in the stator lamination stack. Fig. 5B shows a design of a second lamination with channel sections for creating radial channels in the stator lamination stack.
[0064] Fig.5C shows an arrangement of the first and second laminations according to Fig.5A and 5B for generating the radial channels in the stator lamination stack.
[0065] The radial channel 15.1 of the respective supply path 15 can be formed in various ways. According to Figs. 5A to 5C, it can be formed by several radial channel sections 18, which are radially offset in several adjacent laminations 16 and partially overlap in the radial direction. Alternatively, the radial channel 15.1 can also be created, for example, by a punched-out section or recess in a single lamination 16 of the stator core 4.
[0066] Fig.6 shows a groove cross-section along the line VI-VI in Fig.2A, Fig.7 shows a groove cross-section along the line VII-VII in Fig.2A and Fig.8 shows a groove cross-section along the line VIII-VIII in Fig.2A.
[0067] Fig.9 shows a partial view of the stator according to the invention with twisted laminations for creating support points for the conductor bundles.
[0068] In the stator slots 6, a plurality of support points 11 are formed, spaced apart from one another in the axial direction with respect to the stator axis 3, for clamping and holding the conductor 8 or conductor bundle 9 located in the respective stator slot 6. According to Fig. 10, the support points 11 can each be formed by twisting individual or multiple laminations 16 of the stator laminated core 4, in particular by a group or multiple groups 28 of laminations 16. To form an individual one of the support points 11, the twisted laminations 16 are twisted about the stator axis 3 relative to the other laminations 16 of the stator laminated core 4 (in the opposite direction), for example by a specific twist angle θ). The respective support point 11 is formed, for example, by two groups 28 of laminations 16 that are twisted in opposite directions about the stator axis 3 by the specific twist angle θ).Between the support points 11 according to the invention, the conductor 8 or the conductor bundle 9 of the respective stator slot 6 is mounted in a freely suspended manner, i.e., without contact with the stator core 4. The conductor 8 or the conductor bundle 9 of the respective stator slot 6 is therefore only in contact with the stator core 4 at the support points 11. The respective slot cooling path 14 is at least narrowed at the support points 11. Therefore, a bypass 21 is provided at each support point 11 to guide the cooling medium past the respective narrowed support point 11. The bypasses 21 of the respective stator slot 6 are formed starting from the respective slot inlet 14.1 along the respective slot cooling path 14, for example alternately in the slot base 6g or in the slot head 6h (Fig.2A, Fig.6 and Fig.8), whereby a meandering course of the slot cooling paths 14 can be achieved.
[0069] The respective bypass 21 in the groove base 6g can be formed according to Fig.6, for example, by one or two recesses in the groove flanks 6f at the foot of the stator teeth 5 or a recess in the groove base 6g.
[0070] The respective slot closure 19 has, for the respective stator slot 6 according to Fig.2A, Fig.6 and Fig.8, a plurality of blocking devices 22 spaced apart from one another in the axial direction for adjusting the meandering slot cooling path 14. The blocking devices 22 extend in particular to or close to the conductor 8 or the conductor bundle 9.
[0071] Between adjacent closures 22 of the same stator slot 6, an axially extending passage is provided as a bypass 21 for the respective slot cooling path. Fig. 6 and Fig. 7 show one of the closures 22 of the respective slot closure 19.
Claims
Claims 1. Stator of an electrical machine (2) with a stator axis (3) and with a stator laminated core (4) on which stator teeth (5) and stator slots (6) located between the stator teeth (5) are formed and which comprises a stator yoke (7) connecting the stator teeth (5), wherein the stator slots (6) extend in the radial direction with respect to the stator axis (3) between a slot base (6g) and a slot head (6h), wherein a single conductor (8) or a conductor bundle (9) comprising a plurality of conductors (8), in particular a stack of flat wire conductors, is provided in each of the stator slots (6) to form an electrical stator winding (10), wherein between the slot flanks (6f) of the respective stator slot (6) and the conductor (8) arranged in the stator slot (6) orConductor bundle (9) at least one groove gap (12) is provided, which forms a groove gap channel (13) extending in the axial direction, through which a cooling medium can flow along a groove cooling path (14), characterized in that. - at least one supply path (15) is formed in the stator core (4), which opens into at least one of the stator slots (6) for supplying cooling medium to at least one slot cooling path (14), - the respective supply path (15) with a radial channel (15.1) in a groove Inlet (14.1) of the respective stator slot (6) opens and upstream of the radial channel (15.1) comprises at least one yoke channel (15.2) which runs in the axial direction in the stator yoke (7) and is provided for cooling the stator yoke (7).
2. Stator according to claim 1, characterized in that several yoke channels (15.2) of the at least one supply path (15) are distributed over the circumference of the stator yoke (7) and form a jacket cooling of the stator yoke (7).
3. Stator according to claim 2, characterized in that several of the yoke channels (15.2) are through-channels (23) which each pass completely through the stator laminated core (4) in the axial direction and each have at least one inlet (17) into the respective radial channel (15.1), which is provided in particular in the region of the axial center or in the axial center of the through-channel (15.2).
4. Stator according to claim 2, characterized in that several of the yoke channels (15.2) are short channels (24) which extend from at least one of the two end faces of the stator laminated core (4) in the axial direction to the entrance (17) into the respective radial channel (15.1) and are shorter than a through channel (23), in particular extending into an axial central region of the stator laminated core (4).
5. Stator according to claim 4, characterized in that several pairs (15.2p) of yoke channels (15.2) are provided and distributed over the circumference of the stator yoke (7), wherein the yoke channels (15.2) of each pair (15.2p) extend from the same end face of the stator laminated core (4) and are adjacent when viewed in the circumferential direction, wherein one of the yoke channels (15.2) of each pair (15.2p) is a short channel (24) and the other of the yoke channels (15.2) is a meander channel (25), wherein the respective meander channel (25) comprises a through section (25.1), a deflection section (25.2) and a short section (25.3), wherein for each pair (15.2p) of yoke channels (15.2), the short channel (24) and the short section (25.3) of the meander channel (25) are arranged in pairs are arranged opposite one another, in particular in the same circumferential position.
6. Stator according to claim 5, characterized in that the deflection section (25.2) of the meander channel (25) is formed in the stator laminated core (4) or in a deflection device (26) arranged on the end face of the stator laminated core (4).
7. Stator according to one of the preceding claims, characterized in that an annular distribution channel (20) is arranged at least on one of the two end faces of the stator laminated core (4), which opens into the yoke channels (15.2) and is provided for supplying the supply paths (15) with cooling medium.
8. Stator according to one of the preceding claims, characterized in that in the respective stator slot (6) two slot cooling paths (14) running in opposite directions are provided, which exit at the ends of the respective stator slot (6) via a slot outlet (14.2) as a free jet, in particular in the slot head (6h) or in the slot base (6g).
9. Stator according to one of the preceding claims, characterized in that the radial channel (15.1) of the respective supply path (15) is formed by a punched-out or recess in a single lamination (16) of the stator laminated core (4) or by a plurality of radial channel sections (18) which are radially offset in a plurality of adjacent laminations (16) and partially overlap in the radial direction.
10. Stator according to one of the preceding claims, characterized in that the stator slots (6) are closed by means of at least one slot closure (19) to seal the slot cooling paths (14).
11. Stator according to one of the preceding claims, characterized in that in the stator slots (6) a plurality of support points (11) are formed, which are spaced apart from one another in the axial direction with respect to the stator axis (3), for clamping the conductor (8) or conductor bundle (9) lying in the respective stator slot (6), wherein the support points (11) are each formed by the twisting of individual or several laminations (16) of the stator lamination stack (4), in particular of one group or of several groups (28) of laminations (16).
12. Electrical machine (2) with a stator (1) according to one of the preceding claims.