Stator with phase shift

Abstract

The present invention provides a stator for an electric motor, comprising a stator core and windings located on the stator core. The stator core includes a plurality of teeth defining a plurality of slots. The windings consist of a plurality of segmented conductors connected together to provide a plurality of parallel paths for each phase of the windings, each conductor including (i) an end loop disposed at a crown end of the stator core, (ii) two branches extending through the slots, and (iii) two branch ends extending from the slots at a connecting end of the stator core, each branch end having a torsional portion. The branches of the conductors are arranged in layers in the slots, wherein the layers comprise a total number of layers (L), L being greater than 5 and L / 2 being an odd integer. Each branch end extending from each layer has a common torsional degree associated with the layer from which the branch extends. The common torsional degree associated with at least half of the layers is a first torsional degree, and the common torsional degree associated with at least one of the layers is a second torsional degree different from the first torsional degree.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 191,200, filed May 20, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of electric motors, and more specifically to the arrangement of stator windings. Background Technology

[0004] Winding arrangements for stators are known, including those formed by continuous windings and those formed by segmented conductors. A continuous winding is formed by a series of long, continuous conductors wound through slots in the stator core. Alternatively, a winding formed by segmented conductors is inserted into slots in the stator core, and the ends of the segments are then joined together. Each segmented conductor typically comprises two straight segments connected by end loops. Therefore, segmented conductors are sometimes referred to as “hairpin conductors” or “U-turn conductors.” To form a winding from segmented conductors, the segmented conductors are inserted axially into slots in the stator core, and the ends of the conductors are joined together to form the path of the winding. An example of such a winding formed by segmented conductors is disclosed in U.S. Patent No. 7,622,843, published November 24, 2009, the entire contents of which are incorporated herein by reference.

[0005] Segmented conductors come in a variety of different constructions, including conductors of different sizes and conductors with different pitches (i.e., the distance between straight segments of such conductors) defined by end-turn loops. Based on the size and shape of the segmented conductors and the connections made between them, segmented conductors can be used to form any number of different winding arrangements.

[0006] Different winding arrangements are typically suited to different applications. When a motor with high efficiency and low noise is required, the stator winding phase band is often required to be half-full-half. For example, for a stator with two slots per phase per pole, the phase band would be 4-8-4 (4 conductors in the left slot, 8 conductors in the middle slot, and 4 conductors in the right slot). This is sometimes referred to as a short-pitch winding or a phase-shifted winding. However, forming a winding arrangement with a half-full-half phase band can be challenging from both a design and manufacturing perspective. From a design perspective, all paths of the winding arrangement must be correctly connected to advantageous winding characteristics that produce the performance characteristics required by the motor. From a manufacturing perspective, the connections between straight segments can be challenging because many precise connections must be made at the ends of the stator core where the crowded conductors make connections difficult.

[0007] In view of the foregoing, it will be advantageous to provide a segmented conductor winding arrangement having a relatively simple connection between the segmented conductors. It will also be advantageous that the winding arrangement defines a half-full-half phase band, thereby producing a highly efficient motor with reduced noise. Furthermore, it will be advantageous that such a winding arrangement can be manufactured and produced relatively simply without significantly increasing costs compared to other segmented winding arrangements. These features and advantages of the motor, as well as others, will become more apparent to those skilled in the art from the following detailed description and accompanying drawings. While it is desirable to provide a motor with a winding arrangement that provides one or more of these advantageous features or other advantageous features that are obvious to those reading this disclosure, the teachings disclosed herein extend to those embodiments falling within the scope of the appended claims, regardless of whether they include or implement one or more of the advantages or features mentioned herein. Summary of the Invention

[0008] In at least one embodiment, the stator for the motor includes a stator core and windings located on the stator core. The stator core includes a plurality of teeth defining a plurality of slots. The windings include a plurality of parallel paths for each phase of the windings, each parallel path including (i) a plurality of first end loops disposed at a first axial end of the stator core, (ii) a plurality of conductors extending through the slots, and (iii) a plurality of second end loops disposed at a second axial end of the stator core. The plurality of conductors are arranged in layers in the slots, wherein the layers include a total number of layers (L), the layers including at least two inner layers, two intermediate layers, and at least two outer layers, wherein L / 2 is an odd integer. The first end loops and second end loops define a common pitch (CP). The first end loops and second end loops associated with the intermediate layers alternate between having a pitch equal to CP+1 at the first axial end and a pitch equal to CP-1 at the second axial end.

[0009] In at least one embodiment, a plurality of conductors for a stator winding are connected together to provide a plurality of parallel paths for each phase, each phase having a half-full-half phase band. The winding includes (i) a plurality of first end turns disposed at a first end of the stator core, (ii) straight portions extending through slots, and (iii) a plurality of second end turns disposed at a second end of the stator core. The straight portions of the winding are layered in the slots, wherein the layers comprise a total number of layers (L), where L is greater than 5 and L / 2 is an odd integer. These layers include at least two inner layers, two intermediate layers, and at least two outer layers. A plurality of first conductor portions are disposed in at least two inner layers and form a plurality of first windings around the stator core. A plurality of second conductor portions are disposed in two intermediate layers and form a plurality of second windings around the stator core. A plurality of third conductor portions are disposed in at least two outer layers and form a plurality of third windings around the stator core. Multiple first conductor portions define a common inner end loop pitch at the second end of the stator core, multiple second conductor portions define a common middle end loop pitch at the second end of the stator core, and multiple third conductor portions define a common outer end loop pitch at the second end of the stator core, wherein the common inner end loop pitch is the same as the common outer end loop pitch, and wherein the difference between the common middle end loop pitch and the common inner end loop pitch is 1.

[0010] In at least one additional embodiment, the winding includes (i) a plurality of first end turns disposed at a first end of the stator core, (ii) a straight portion extending through a slot, and (iii) a plurality of second end turns disposed at a second end of the stator core. The straight portion of the conductor is arranged in layers within the slot, wherein the layers comprise a total number of layers, including at least two inner layers, at least two outer layers, and two intermediate layers located between the inner and outer layers. A majority of the first end turns and a majority of the second end turns have a common pitch (CP), wherein a majority of the first end turns of the straight portion connecting the two intermediate layers have a pitch of CP+1, and a majority of the second end turns of the straight portion connecting the two intermediate layers have a pitch of CP-1. Attached Figure Description

[0011] Figure 1 This is a perspective view of the welded end of a stator core, which has a segmented conductor winding arrangement thereon.

[0012] Figure 2 It is used to form Figure 1 A three-dimensional view of an exemplary segmented conductor with winding arrangement.

[0013] Figure 3 This is a tabular view of a first embodiment of a segmented conductor winding arrangement having half-full-half phase bands and eight conductors per slot, the winding arrangement being configured to... Figure 1The stator is used in conjunction with it.

[0014] Figure 4 This is a tabular view of a second embodiment of a segmented conductor winding arrangement having half-full-half phase bands and six conductors per slot, the winding arrangement being configured to... Figure 1 The stator is used in conjunction with it.

[0015] Figure 5A Is Figure 4 A three-dimensional view of the segmented conductors used in the first and second slot layers of the winding arrangement.

[0016] Figure 5B Is Figure 4 A three-dimensional view of the segmented conductors used in the third and fourth slot layers of the winding arrangement.

[0017] Figure 5C Is Figure 4 A three-dimensional view of the segmented conductors used in the fifth and sixth slot layers of the winding arrangement.

[0018] Figure 6 yes Figure 4 A three-dimensional view of the conductor at the welded end of the winding arrangement.

[0019] Figure 7 This is a tabular view of a third embodiment of a segmented conductor winding arrangement having half-full-half phase bands and six conductors per slot, as well as radially staggered bridging end loops. This winding arrangement is configured to... Figure 1 The stator is used in conjunction with it.

[0020] Figure 8 yes Figure 7 A three-dimensional view of the conductor at the welded end of the winding arrangement. Detailed Implementation

[0021] This paper discloses a stator for an electric motor. The stator includes a stator core on which windings are formed. The windings include conductors arranged in layers in slots of the stator core. The conductors are arranged to provide a half-full-half phase band, wherein the left slot of each slot group is half-full, the middle slot is full, and the right slot is half-full. In such a phase band, the conductors in the first half-continuous layer of each slot group move one slot to the left (or right) of the conductors in the second half-continuous layer. To achieve this winding arrangement with half-full-half phase bands, many different end-turn arrangements are possible. The winding arrangement selected for the motor depends on many factors, including the total number of layers (L) of conductors in each slot, and in particular the number of layer pairs in each slot (i.e., L / 2).

[0022] Overall structure of a stator core with segmented conductor windings

[0023] Figure 1 A perspective view of a stator 10 for an electric motor is shown, including a stator core 12 on which windings 20 are formed. The stator core 12 is made of a ferromagnetic material and is typically formed of multiple steel plates that are stamped and stacked on top of each other to form a lamination stack. The stator core 12 is generally cylindrical in shape, defined by a central axis 18, and includes an inner circumferential surface and an outer circumferential surface. The inner circumferential surface defines the inner diameter (ID) of the stator. The outer circumferential surface defines the outer diameter (OD) of the stator.

[0024] Multiple teeth 14 are formed inside the stator core 12 and point toward the central axis 18. Each tooth 14 extends radially inward and terminates on an inner circumferential surface. Axial grooves 16 are formed between the teeth 14 of the stator core 12. Each groove 16 is defined between two adjacent teeth such that two adjacent teeth form two opposing radial walls of a groove. Both the teeth 14 and the grooves 16 extend from a first end 30 (i.e., the "crown end") of the core to a second end 32 (i.e., the "connecting end" or "welding end").

[0025] Radial openings leading to slot 16 are formed along the inner circumferential surface of stator core 12. When slot 16 is semi-closed, the width of each radial opening leading to slot 16 at the inner circumferential surface is smaller than the width at a more radially outward location (i.e., the slot location closer to the outer circumferential surface). In addition to the radial openings leading to slot 16 through the inner circumferential surface (i.e., for both open and semi-closed slots), axial openings leading to slot 16 are also provided at opposite ends 30, 32 of stator core 12.

[0026] like Figure 1 As shown, the stator core 12 is configured to hold the winding arrangement 20 within slots 16 of the stator core 12. The winding arrangement 20 is formed by a plurality of interconnected conductor paths held within the slots 16. The conductor paths include interconnected conductor portions extending through the slots and generally wound around the core 12. Each slot 16 is configured to hold a number of in-slot segments in a “layer” of the slot, wherein the in-slot segments are generally arranged in a single row such that each layer of the slot retains a single conductor segment.

[0027] Segmented conductors for winding arrangement

[0028] In at least some embodiments, the winding arrangement is formed by a plurality of interconnected segmented conductors. (Refer to...) Figure 2 An exemplary segmented conductor 22, separate from the winding arrangement 20, is shown. The segmented conductor 22 is formed of a length of conductive material, such as copper. The copper may be insulated with an external electrical insulating layer. Figure 2 The exemplary segmented conductor shown also has a rectangular cross-sectional shape.

[0029] Each segment conductor includes two branches 26, with an end loop 24 connecting the two branches 26. Each branch includes a straight portion 27, a twisted portion 28, and an end portion 29. Both the straight portion 27 and the end portion 29 extend in the axial direction. The straight portion 27 is configured to extend axially through a slot in the stator core and may also be referred to as the "in-slot portion". The twisted portion 28 has an axial component, a circumferential component, and a radial component, and extends between the straight portion 27 and the end portion 29.

[0030] Each segment conductor 22 has an end loop 24 (which may also be referred to as an "end turn" or "U-turn") located on the crown end 30 of the core, defining a 180° change in the orientation of the segment conductor. The end loop also extends a circumferential distance associated with the number of slots in the stator core. This distance is referred to as the "pitch" (P) of the end loop. The end loop pitch P is defined as the end loop connecting the first straight segment in a specific slot number (S) to a straight segment in slot P+S. For example, a 6-pitch end loop (i.e., P=6) is defined as connecting the straight segment in slot 1 (i.e., S=1) of the core to a straight segment in slot 7 (i.e., 6+1=7). Figure 2 In the exemplary conductor, the end loop 24 is shown to extend a distance equal to six slots of the core (i.e., P = 6). Thus, as noted in the example above, if the straight portion 27 of the first branch is positioned in slot 1 of the core, then the straight portion 27 of the second branch is positioned in slot 7 of the core.

[0031] During the formation of winding 20, branches 26 are axially inserted into slots 16 of core 12, with all end loops 24 disposed on the crown end 30 of the core. For each segment conductor, one branch is located in one layer of the slot, while another branch is located in an adjacent layer of another slot, wherein the two slots are separated on the crown end 30 of core 12 by the pitch of the end loops 24. After insertion into the slot, the branch ends extend axially from the connecting ends 32 of the stator core. Then, the ends of branches 26 of each segment conductor 22 are bent / twisted in opposite directions, such that the twisted portion 28 of one branch extends from the twisted portion 28 of the other branch in opposite circumferential directions. This circumferential distance spanned by each twisted portion 28 is associated with the number of slots in stator core 12 and is referred to as the “twist” (T) of branch 26. Figure 2 In the exemplary conductor, each branch 26 has a twist of three slots.

[0032] Following the twisted branch 26, the end portions 29 of the different conductors are joined together at the connecting end 32 of the stator core 12 (e.g., by welding or other connection methods) to complete the winding 20. Simultaneously, the degree of twist (T) at which the two segmented conductors are connected at their respective end portions 29 forms an end loop defined by the pitch (P) at the welded end 32 of the stator core. Therefore, it will be appreciated that each end loop 24 at the crown end 30 has a pitch defined by the end loop of the associated segmented conductor, while each end loop 24 at the welded end 32 has a pitch defined by two degrees of twist (T) of the two connected branch ends (i.e., the connecting end portions 29 of the two branch ends).

[0033] Although Figure 2 An exemplary embodiment of segmented conductors for winding arrangement 20 is shown, but it will be appreciated that conductor segments of different shapes are also conceivable. For example, the pitch of the end loop 24 and the degree of twist at the branch ends can vary depending on the segmented conductors used in winding arrangement 20. As another example, the winding leads 40 can be provided by elongated end portions 29 extending beyond the welded ends 32 of the stator core 12.

[0034] Winding arrangement with an even number of layer pairs

[0035] Now refer to Figure 3 A tabular view of the stator winding arrangement 20 is shown, wherein the winding arrangement is formed by a plurality of segmented conductors 22, as described above. Figure 3 As indicated in the top two rows of the table, winding arrangement 20 includes twelve poles (as indicated by the twelve slot groups associated with each) and is configured for use in a stator core with seventy-two slots. Figure 3 As indicated in the leftmost column, the conductors of the winding (i.e., the straight portions 27 of the conductor branches) are arranged in a single row in eight layers (L) in each of the seventy-two slots. In the disclosed embodiment of the winding, layer 1 is the inner layer of each slot and layer 8 is the outer layer of each slot; however, it will be appreciated that the winding can also be constructed in the opposite arrangement, where layer 1 is the outer layer and layer 8 is the inner layer of the slot.

[0036] because Figure 3 The winding 20 consists of eight layers, and L / 2 is an even number (i.e., L / 2 = 8 / 2 = 4), which means that for Figure 3 The winding has an even number of "layer pairs", where each layer pair is associated with a single wrap of the winding phase around the stator core (i.e., each path is defined by the winding phase and includes four parallel paths: in Figure 3The path is defined as A, B, C, and D, and each winding of a path extends through twelve slot groups. The straight conductor portion of each path is alternately arranged in layers 1 and 2 (first layer pair) for the first winding on the stator core. The path then transitions to layers 3 and 4 (second layer pair) for the second winding on the stator core, then to layers 5 and 6 (third layer pair) for the third winding on the stator core, and finally to layers 7 and 8 (fourth layer pair) for the fourth winding on the stator core.

[0037] Figure 3 Only one phase of the winding is shown in the diagram. It will be recognized that for a three-phase winding, the other two phases are the same as the phase shown, but the other first phase moves two slots and the other second phase moves four slots.

[0038] like Figure 3 As shown, each path of the winding comprises four parallel paths (i.e., paths A, B, C, and D indicated in the table). The leads 40 of each path are indicated by a bold / dark box around the associated path. The winding 20 defines a half-full-half phase band. In other words, for each pole and each phase, the conductors of a given slot group are distributed across three slots, where the left slot is half-full, the middle slot is fully full, and the right slot is half-full. Specifically, Figure 3 The windings have a 4-8-4 phase band, such that each slot for a given phase comprises four left conductors, eight center conductors, and four right conductors. Figure 3 As can be seen, layers 1 to 4 are all similar, with conductors for the four paths (AD) arranged in the left and middle slots of each slot group, and layers 5 to 8 are all similar, with conductors for the four paths (AD) arranged in the right and middle slots. In other words, Figure 3 The winding arrangement includes moving the conductors in layers 1 to 4 to the left of the conductors in layers 5 to 8 by one slot.

[0039] Figure 3 The table includes an upper portion 36 and a lower portion 38 to readily illustrate the end loops used for the winding. In the upper portion 36 and lower portion 38 of the table, lines extending between slots represent the overall arrangement of the end loops extending between slots. The upper portion 36 shows the end loop 24 on the crown end 30 of the stator core, where each end loop extends between two conductors in two different slots of the winding (i.e., each end loop is provided by a pre-formed end loop 24 of a segmented conductor 22). The lower portion 38 shows the end loop formed on the connecting end 32 of the stator core, which extends between conductors in the respective slots of a phase of the winding (i.e., the end loop formed by the connection between the twisted branch ends and the end portions 29).

[0040] In the upper part 36 of the table, the lines extending between the slots represent the overall arrangement of the end loops on the crown end 30 as viewed from the crown end. Each line extending between the slot groups is associated with a pair of end loops on the crown end of the stator. For example, the top line extending between the slot groups associated with poles 1 and 2 in the upper part 36 of the table represents the first and second end loops on the crown end 30 of the core. The first end loop connects the straight conductor of path C in layer 1 of slot 5 to the straight conductor of path C in layer 2 of slot 11. The second end loop connects the straight conductor of path D in layer 1 of slot 4 to the straight conductor of path D in layer 2 of slot 10. All end loops 24 on the crown end are staggered six-pitch end loops, except for a special set of over-under end loops 44 located between poles 8 and 9 and between poles 9 and 10. Each pair of over-under end loops 44 includes a seven-pitch upper end loop that spans a five-pitch lower end loop. It should be noted that all end loops 24 on the crown tip are regular end loops confined within a single layer pair. In other words, all end loops 24 extend between the layers of one of the first layer pair (i.e., layers 1 and 2), the second layer pair (i.e., layers 3 and 4), the third layer pair (i.e., layers 5 and 6), or the fourth layer pair (i.e., layers 7 and 8).

[0041] Figure 3 The lower part 38 of the table is similar to the upper part 36, with lines extending between the slots indicating the overall arrangement of end loops on the connecting end 32 as viewed from the crown end 30 (i.e., looking through the stator towards the connecting end). A line is associated with a pair of end loops on the connecting end 32 of the stator. For example, the bottom line extending between poles 1 and 2 in the lower part 38 of the table indicates the first end loop and the second end loop. The first end loop connects the straight conductor of path A in layer 8 of slot 5 to the straight conductor of path A in layer 7 of slot 11. The second end loop connects the straight conductor of path B in layer 8 of slot 6 to the straight conductor of path B in layer 7 of slot 12.

[0042] Circles 42 on the lines of the lower part 38 of the table indicate that two end portions of a branch end of a given path are connected together (e.g., welded together) to form an associated end loop. For example, the circle on the bottom line extending between poles 1 and 2 in the lower part 38 of the table indicates a connection between the end portions of the A path branch in slots 5 and 11, and another connection between the end loops of the end portions of the B path branch in slots 6 and 12. Each branch end is twisted with multiple slots to form a winding arrangement, which is described in further detail below.

[0043] Most of the end loops 24 on the connecting end 32 of the stator core are regular end loops connecting straight conductor segments within the same layer pair (e.g., end loop 24 connecting path A conductor in layer 8 of slot 53 to path A conductor in layer 7 of slot 59—this end loop extends between the two conductors of the fourth layer pair). However, in addition to the regular end loops extending between conductors of the same layer pair, the end loops on the connecting end 32 also include a set of bridging end loops 46 connecting one layer pair to an adjacent layer pair. For example, in Figure 3 The bridging end wire turn 46 extending between poles 3 and 4 in the lower part 38 of the table includes a first bridging end wire turn and a second bridging end wire turn. The first bridging end wire turn connects the path A conductor in layer 2 of slot 17 to the path A conductor in layer 3 of slot 23 (thus connecting the first layer pair of path A to the second layer pair), and the second bridging end wire turn connects the path B conductor in layer 2 of slot 16 to the path B conductor in layer 3 of slot 22 (thus connecting the first layer pair of path B to the second layer pair). Figure 3 The lower part 38 of the table shows six pairs of bridging end turns, including three pairs of bridging end turns extending between the slots associated with poles 3 and 4, and three pairs of bridging end turns extending between the slots associated with poles 4 and 5. Two pairs of bridging end turns connect the conductors in layer 2 to the conductors in layer 3 (i.e., connect the first layer pair to the second layer pair), two pairs of bridging end turns connect the conductors in layer 4 to the conductors in layer 5 (i.e., connect the second layer pair to the third layer pair), and two pairs of bridging end turns connect the conductors in layer 6 to the conductors in layer 7 (i.e., connect the third layer pair to the fourth layer pair).

[0044] As mentioned above, Figure 3 The winding has an even number of layer pairs (i.e., L / 2 = 8). This allows the stator to be designed such that all end loops have a common pitch (CP) at the connection end 32, except for the bridging end loops extending between two adjacent intermediate layers of the winding (i.e., bridging end loops that allow each path to transition between the second layer pair defined by layers 3 and 4 and the third layer pair defined by layers 5 and 6). The pitch of these bridging end loops is CP-1 or CP+1. For example, in which the winding is defined by 2 slots per phase per pole and 8 wires per slot... Figure 3 In the winding arrangement, all end loops on connecting end 32 have a common pitch (CP) of 6, except for the cross loops extending between layers 4 and 5. The pitch of these special end loops is equal to five or seven (CP-1 or CP+1). Therefore, given the presence of certain special end loops (e.g., certain “bridging end loops” or certain “upper and lower” end loops), it will be appreciated that the term “common pitch” as used herein refers to the regular or most common pitch of the winding, or the most common pitch for a given layer pair, as appropriate.

[0045] To form end turns with the same common pitch of 6 at the connection end 32, except for special end loops with a pitch of 5 or 7 (CP-1 or CP+1), the branches of the conductor extending from each layer are bent with different degrees of twist. A simple method to form an end loop with a common pitch of six at the connection end of the core is to twist the branch in one layer clockwise by three slots and the branch in the adjacent layer (but without six slots) counterclockwise by three slots, and then connect the branch ends to form an end loop with a pitch of six. However, as previously stated, Figure 3 The winding arrangement includes shifting the conductors in layers 1 to 4 one slot to the left of the conductors in layers 5 to 8. Therefore, the bridging end loop extending from layer 4 to layer 5 must be a seven-pitch end loop (or, if layers 1 to 4 are shifted one slot to the right, the bridging end loop 46 extending from layer 4 to layer 5 is a five-pitch end loop). Therefore, when a seven-pitch bridging end loop is required, it is insufficient to conventionally twist the branch ends in layer 4 three slots in one direction and the branch ends in layer 5 three slots in the opposite direction, as this would only create a six-pitch bridging end loop between layers 4 and 5. However, a seven-pitch end loop can be created by twisting the branch ends in layer 4 three slots and the branch ends in layer 5 four slots. Therefore, the bridging end turns 46 extending from layer 4 to layer 5 (i.e., those between poles 3 and 4 and those between poles 4 and 5) are seven-pitch end turns, as... Figure 3 As shown in the lower part 38 of the table. Therefore, for Figure 3 Regarding the windings, it is important to note that the twisting of the branch ends at the connecting ends of the core is as follows:

[0046] - Layer 1 to Layer 4 (i.e., the first semi-continuous layer): Twist all branch ends into three (3) slots (the branch ends in the alternating layers are twisted in opposite directions to form a standard six-pitch end wire loop for the first layer pair (i.e., for layer 1 and layer 2) and the second layer pair (i.e., for layer 3 and layer 4), and form a six-pitch bridging end wire loop between layer 2 and layer 3).

[0047] - Layer 5: Twist all branch ends into four (4) slots (thus forming a seven-pitch bridging end loop between layers 4 and 5, wherein layer 4 is twisted into three slots in one direction and layer 5 is twisted into four slots in the opposite direction);

[0048] - Layer 6: Twist the two (2) slots (thus forming a six-pitch end loop for the third layer pair (i.e., layers 5 and 6), wherein layer 5 is twisted in the opposite direction to layer 6);

[0049] - Layer 7: Twist four (4) slots (thus forming a six-pitch bridging end loop between Layer 6 and Layer 7, wherein Layer 7 is twisted in the opposite direction to Layer 6); and

[0050] - Layer 8: Twist two (2) slots (thus forming a six-pitch end loop for the fourth layer pair (i.e., layers 7 and 8), with layer 7 twisted in the opposite direction to layer 8)

[0051] As a result of the aforementioned reversal, it will be recognized that Figure 3 The embodiment discloses a winding consisting of multiple conductor branches disposed in layers (L) of multiple slots, wherein L is greater than 5, and in particular L equals 8. These layers include a first semi-continuous layer and a second semi-continuous layer, wherein each branch end extending from each layer has a common torsion associated with the layer from which the branch extends. The common torsion associated with each layer in the first semi-continuous layer is a first common torsion (CT1, where CT1 = 3). The common torsion associated with each layer in the second semi-continuous layer alternates between a second common torsion (CT2) and a third common torsion (CT3), wherein CT2 ≥ CT1 + 1 (i.e., CT2 ≥ 4), and wherein CT3 ≤ CT1 - 1 (i.e., CT3 ≤ 2).

[0052] also, Figure 3 The winding arrangement can be considered as a winding in which each end turn at the connecting end of the core connects to a straight portion of a conductor disposed in two consecutive layers of two slots, wherein each end turn includes a first common torsion associated with one of the two consecutive layers and a second common torsion associated with the other of the two consecutive layers. In such an embodiment, the first common torsion and the second common torsion are the same for the end turns of the first half-continuous layer (e.g., a common torsion of three in layers 1 to 4), but for the end turns of the second half-continuous layer, the first common torsion and the second common torsion alternate between different common torsions (e.g., a common torsion of four in layers 5 and 7, and a common torsion of two in layers 6 and 8).

[0053] A winding arrangement having an odd number of layer pairs and aligned branch ends, including cross branch ends.

[0054] Now refer to Figure 4 , showed Figure 3 A tabular view of an alternative implementation of the winding arrangement. Similar to... Figure 3 , Figure 4 The winding arrangement 20 is a three-phase winding, with four parallel paths (i.e., paths AD) for each phase. However, in Figure 4 In the middle, the conductor is arranged in multiple layers (L) in each slot, such that L / 2 is an odd number (i.e., the number of layer pairs is in the range of L / 2). Figure 4 The middle is an odd number, and Figure 3 (The opposite of even numbers). In particular, for Figure 4The winding arrangement has six layers of conductors in each slot, such that L = 6 and L / 2 = 3 (i.e., an odd number). For simplicity, in Figure 4 Only the end turns between path A and path B are shown. Figure 4 In the diagram, the end wire loop 24 on the crown end 30 is indicated by a dashed arrow, and the end wire loop on the connecting end is indicated by a solid arrow. It will be appreciated that the end wire loop between paths C and D is similar to the end wire loops shown for paths A and B, but this end wire loop is located on the opposite side of the core. For example, although... Figure 4 The end loops of paths A and B, extending between the slots associated with poles 1 and 2, are shown located on the crown end 30 of the core. However, it will also be appreciated that the end loops of paths C and D, extending between the slots associated with poles 1 and 2, are located on the connecting end 32 of the core. Therefore, with... Figure 3 Different, for the sake of simplicity, for Figure 4 A tabular view of the winding arrangement, without showing the upper and lower sections.

[0055] because Figure 4 The winding arrangement has an odd number of L / 2 (i.e., L / 2 = 3), therefore the torsional force and pitch of the winding arrangement must be determined from... Figure 3 The winding arrangement (where L / 2 is an even number) is adjusted. First, it will be recognized that... Figure 4 In the winding arrangement, two intermediate layers are associated with a layer pair, where the conductors in that layer pair form a primary winding on the core (i.e., the two intermediate layers are layers 3 and 4, and layers 3 and 4 are the same layer pair forming a primary winding on the core). This differs from... Figure 3 The winding arrangement, because Figure 3 The intermediate layer of the winding arrangement is associated with two different layer pairs, which provide two different windings on the core. Therefore, only bridging the end turns is needed for connection. Figure 3 The intermediate layers (i.e., the intermediate layers include layers 4 and 5, where layer 4 is part of a layer pair associated with layers 3 and 4, and layer 5 is part of another layer pair associated with layers 5 and 6). Similar to... Figure 3 , Figure 4The winding arrangement is defined by an intermediate layer pair (i.e., a layer pair consisting of layers 3 and 4), which includes one layer (i.e., layer 3) having a first common torsion degree matching the first semi-continuous layer (i.e., CT1 = 3 in layers 1 to 3), and another layer (i.e., layer 4) having a second common torsion degree (CT2) one slot larger than the first common torsion degree (i.e., CT2 = CT1 + 1 = 3 + 1 = 4 in layer 4). The remaining layers include a third common torsion degree (CT3) in layer 5, which is 1 less than the first common torsion degree (i.e., CT3 = CT1 - 1 = 3 - 1 = 2 in layer 5). Advantageously, since the common torsion degrees of layers 4 to 6 are different from those of layers 1 to 3, even if L / 2 is an odd number, Figure 4 The windings are also equipped with a half-full-half phase belt. Specifically, in Figure 4 In the arrangement, layers 1 to 3 include conductors in the left side and middle slot of each pole group, while layers 4 to 6 include conductors in the right side middle slot.

[0056] In addition to the differences mentioned above Figure 3 Winding arrangement and Figure 4 Another difference between the winding arrangements is that the common pitch of the end loops 24 differs for different layer pairs on the crown end (and...). Figure 3 All end loops on the end of the central crown have the same common pitch (opposite). Figure 4 In the winding arrangement, for the inner and outer layer pairs, the common pitch (CP1) of all end loops is six (i.e., CP1 = 6) (i.e., the common pitch of the end loops of layer 1 and layer 2 is six, and the end loops of layer 4 and layer 6 have a common pitch), except for the four upper and lower end loops 44 between poles 5 and 6 at the crown end (where the upper end loop has a pitch of 7 and the lower end loop has a pitch of 5) and the four upper and lower end loops 44 between poles 11 and 12. However, for layers 3 and 4 (i.e., the two intermediate layers of the winding), the common pitch (CP2) at the crown end is 5 (i.e., CP2 = CP1 - 1), while the common pitch (CP3) at the connecting end is seven (i.e., CP3 = CP1 + 1), except for the four upper and lower end loops 44 between poles 5 and 6 at the crown end and the four upper and lower end loops 44 between poles 11 and 12. Therefore, in Figure 4In the example, winding 20 has two slots per pole per phase and six conductors per slot, wherein layers 1, 2, 5, and 6 are all associated with end loops having a common pitch of six (i.e., CP1 = 6, except for the upper and lower end loops at the crown end), layers 3 and 4 have end loops at one axial end associated with a common pitch of 5 (i.e., CP2 = 5, except for the upper and lower end loops at the crown end) and at opposite axial ends associated with a common pitch of 7 (i.e., CP3 = 7, except for the upper and lower end loops at the connecting end). Therefore, it will be appreciated that in Figure 4 In one implementation, the end loops of the two intermediate layers alternate between having a pitch equal to CP1+1 at one axial end of the core and having a pitch equal to CP1-1 at the opposite axial end of the core.

[0057] In order to form Figure 4 The winding arrangement involves axially inserting a U-shaped conductor into a slot and twisting the branch ends. Adjacent ends of the branches are then welded together to form an end loop with a predetermined pitch at the connection end, as described above (e.g., a six-pitch or other pitch end loop). Figure 4 The required end circuits for the winding arrangement are in Figures 5A to 5C Each of these is shown in the table below, which is described in further detail in the following paragraphs.

[0058] Now refer to Figure 5A It shows the method for forming Figure 4 An exemplary U-shaped conductor of two conductor paths (e.g., path A and path B) in the winding arrangement of layers 1 and 2, particularly the conductor path extending from pole 5 to pole 8. Figure 5A As shown, two end loops 24 on the crown tip 30 extend between the slots of poles 5 and 6, forming upper and lower end loops with pitches of 5 and 7, respectively. The remaining end loops of layers 1 and 2 on the crown tip 30 are six-pitch end loops, including two end loops extending between the slots of poles 7 and 8, as shown. Figure 5A As shown. At the other end of the core, namely at the connecting end 32, the branch ends are twisted to provide adjacent ends, and then welded together to form an end loop. As previously described, all end loops 24 of layers 1 and 2 on the connecting end 32 are six-pitch end loops. To optimize the resistance and end loop height in layers 1 and 2, one branch end in layer 1 is twisted three slots in one direction (e.g., clockwise), while one branch end in layer 2 is twisted three slots in the opposite direction (e.g., counterclockwise). When the ends of these branch ends are joined together, they form a six-pitch end loop between layers 1 and 2 on the connecting end 32 of the core.

[0059] Now refer to Figure 5BIt shows the method for forming Figure 4 An exemplary U-shaped conductor of two conductor paths (e.g., path A and path B) in layers 3 and 4 of the winding arrangement, particularly the conductor path extending from pole 5 to pole 8. Figure 5B As shown, two end loops 24 on the crown tip 30 extend between the slots of poles 5 and 6, forming upper and lower end loops with pitches of 4 and 6, respectively. The remaining end loops of layers 3 and 4 on the crown tip 30 are five-pitch end loops, including two end loops extending between the slots of poles 7 and 8, as shown. Figure 5B As shown. At the other end of the core, namely at the connecting end 32, the branch ends are twisted to provide adjacent ends, and then welded together to form an end loop. As previously described, all end loops 24 of layers 3 and 4 on the connecting end 32 are seven-pitch end loops. To form these end loops, the branch ends of layer 3 are twisted with three grooves, while the branch ends of layer 4 are twisted with four grooves. The ends of these branch ends are then joined together to form a seven-pitch end coil on the connecting end 32 of the core between layers 3 and 4.

[0060] Now refer to Figure 5C It shows the method for forming Figure 4 An exemplary U-shaped conductor of the two conductor paths (e.g., path A and path B) of layers 5 and 6 of the winding arrangement, particularly the conductor path extending from pole 5 to pole 8. Figure 5C As shown, two end loops 24 on the crown tip 30 extend between the slots of poles 5 and 6, forming upper and lower end loops with pitches of 5 and 7, respectively. The remaining end loops of layers 3 and 4 on the crown tip 30 are six-pitch end loops, including two end loops extending between the slots of poles 7 and 8, as shown. Figure 5C As shown. At the other end of the core, namely at the connecting end 32, the branch ends are twisted to provide adjacent ends, and then welded together to form an end loop. As previously described, all end loops 24 of layers 5 and 6 on the connecting end 32 are six-pitch end loops. To form these end loops, the branch ends of layer 5 are twisted with two slots, while the branch ends of layer 6 are twisted with four slots. The ends of these branch ends are then joined together to form a six-pitch end coil on the connecting end 32 of the core between layers 5 and 6.

[0061] In view of the above Figures 4 to 5CAs illustrated by the torsion diagram, it will be apparent that bridging end loops between layers 2 and 3, and between layers 4 and 5, can be easily formed at the connecting ends 32 of the stator core. The common torsion of each layer from layers 1 to 3 is three slots, thus a six-pitch bridging end loop can be easily formed between layers 2 and 3 via adjacent branch ends located between poles 2 and 3. Similarly, since the common torsion of layer 4 is 4 and that of layer 5 is 2, a six-pitch bridging end loop can also be easily formed between layers 4 and 5 via adjacent branch ends located between poles 2 and 3.

[0062] Advantageously, Figure 4 The winding arrangement provides a winding in which all adjacent end portions 29 of the twisted branch ends (including end portions associated with the bridging end loops between layer pairs) are aligned in radial rows on the connecting ends of the stator core, the number of radial rows being equal to the number of slots in the core. Figure 6 It shows Figure 4 A perspective view of the connection ends of the winding arrangement, including multiple end portions 29 of the branch ends forming end loops 24. As shown, the end portions 29 of the torsional branch ends from adjacent layers are all radially aligned, including end portions 29a forming regular end loops within layer pairs, and end portions 29b forming bridging end loops 46 between layer pairs. Figure 6 As shown, each radial row includes three pairs of adjacent end portions 29, and all end portions 29 are aligned in the radial row. Adjacent end portions are connected to form end loops. Arrow 48 illustrates the connection between adjacent end portions 29, which creates a bridging end loop 46 connecting two different layer pairs (e.g., a bridging end loop connecting a first layer pair provided with layers 1 and 2 to a second layer pair provided with layers 3 and 4). It should be noted that the adjacent end portions associated with the bridging end loop 46 are located in the same row as the lead 40. Therefore, only two pairs of adjacent end portions 29 are provided in these rows, particularly the adjacent end portions connected between rows 2 and 3 and between rows 4 and 5. In all other rows excluding the lead 40 and the bridging end loop 46, each connected end portion is associated with a layer pair, i.e., the connection of the end portions between layers 1 and 2, between layers 3 and 4, and between layers 5 and 6. Since adjacent end portions 29 are all aligned in the radial rows, including those associated with the bridging end turns 46, the connection between adjacent end portions is formed by welding pairs of adjacent branch ends together in each radial row.

[0063] In light of the foregoing, it will be recognized that, in combination Figures 4 to 6The winding arrangement in the discussed embodiment consists of multiple conductor branches disposed in layers (L) of multiple slots, where L equals 6. These layers include a first semi-continuous layer and a second semi-continuous layer, wherein each branch end extending from each layer has a common torsion associated with the layer from which the branch extends. The common torsion associated with each layer of the first semi-continuous layer (i.e., layers 1 to 3) is a first common torsion (CT1, where CT1 = 3). The common torsion associated with each layer of the second semi-continuous layer (i.e., layers 4 to 6) alternates between a second common torsion (CT2) and a third common torsion (CT3), where CT2 ≥ CT1 + 1 (i.e., CT2 ≥ 4), and where CT3 ≤ CT1 - 1 (i.e., CT3 ≤ 2).

[0064] in addition, Figures 4 to 6 The winding arrangement can be considered as a winding in which each end turn at the connecting end of the core connects to the straight portion of a conductor disposed in two consecutive layers in different slots, wherein each said end turn includes a first common torsion associated with one of the two consecutive layers and a second common torsion associated with the other of the two consecutive layers. In such an embodiment, the first common torsion and the second common torsion are the same for the end turns of the first half-continuous layer (e.g., a common torsion of three in layers 1 to 3), but for the end turns of the second half-continuous layer, the first common torsion and the second common torsion alternate between different pitches (e.g., a common torsion of four in layers 4 and 6, and a common torsion of two in layer 5).

[0065] also, Figures 4 to 6 The winding arrangement can be considered as a winding in which the straight portions are arranged in layers in the slots, wherein the layers include a total number of layers, comprising at least two inner layers, at least two outer layers, and two intermediate layers located between the inner and outer layers. In such an embodiment, most of the first end turns and most of the second end turns have a common pitch (CP), most of the first end turns of the straight portions connecting the two intermediate layers have a pitch of CP+1, and most of the second end turns of the straight portions connecting the two intermediate layers have a pitch of CP-1.

[0066] Winding arrangement with an odd number of layer pairs and staggered bridging branch ends

[0067] Now refer to Figure 7 , showed Figure 4 A tabular view of an alternative implementation of the winding arrangement. Figure 7 Winding arrangement and Figure 4 Similarly, it is a three-phase winding 20, with each phase having four parallel paths (i.e., paths AD). And... Figure 4 Same, Figure 7The conductors in the winding are arranged in multiple layers (L) in each slot, such that L / 2 is an odd number. Specifically, there are six layers of conductors in each slot, such that L / 2 = 3. For simplicity, in Figure 7 Only the end turns between path A and path B are shown. Figure 4 In the diagram, the end loop 24 on the crown end 30 is indicated by a dashed arrow, and the end loop on the connecting end is indicated by a solid arrow. It will be appreciated that the end loop (not shown) between path C and path D is similar to the end loop shown for paths A and B, but this end loop is located on the other side of the core.

[0068] Figure 7 and Figure 4 The comparison shows that the conductor arrangement within the slot and the end turn pitch are the same for each winding arrangement. However, in Figure 7 In the winding arrangement, the torsion and... Figure 4 The torsion of the winding arrangement differs slightly. Specifically, in Figure 7 In this embodiment, the twisting of the connecting end is as follows:

[0069] - Layer 1 and Layer 2: Twist all branch ends into 3 slots, but the direction of Layer 1 is opposite to that of Layer 2;

[0070] - Layers 3 and 4: Twist all branch ends by 3.5 grooves, but in the opposite direction to Layer 3 compared to Layer 4; and

[0071] - Layers 5 and 6: Twist all branch ends into 3 slots, but in the opposite direction to layer 5 compared to layer 6.

[0072] The foregoing description is used for Figure 7 A possible torsional arrangement at the branch ends of the winding. Also in Figure 7 In at least one alternative implementation specified herein, the reversal is as follows:

[0073] - Layer 1 and Layer 2: Twist all branch ends into 3 slots, but the direction of Layer 1 is opposite to that of Layer 2;

[0074] - Layer 3: Twist all branch ends into 3 slots in the opposite direction to layer 2;

[0075] - Layer 4: Twist all branch ends into four slots in the opposite direction to Layer 3; and

[0076] - Layers 5 and 6: Twist all branch ends into 3 slots, but in the opposite direction to layer 5 compared to layer 6.

[0077] and Figure 4 Compared to the winding arrangement, Figure 7The torsion in the winding arrangement creates an end loop with the shortest triangular shape, thus resulting in a preferred shorter path and resistance level. However, due to... Figure 7 The twist in the winding arrangement, where the ends associated with the bridging end circuit 46 are neither adjacent nor aligned radially. This is in Figure 8 As shown in the diagram, arrow 49 indicates that the end portion 29 of the bridging end loop 46 is not aligned in the radial direction. Specifically, as... Figure 8 As shown in box 50, the desired connection between the end portions associated with the bridging end coil 46 is indicated by arrow 49, and the arrows are offset circumferentially from each other and not radially aligned.

[0078] Even if the end portions associated with the bridging coils are not radially aligned, relatively simple options can be used to connect the end portions and complete the bridging loop. For example, one option is to make the branch end associated with the bridging coil longer than the branch ends of the other segment conductors and weld the end portion of the branch end associated with the bridging coil above other hairpin welds. Another option is to use separate copper rails / jump wires to connect the end portions of the bridging coils. Yet another option is to twist the end portions of the bridging coils in a manner different from other twists in their layers, thereby aligning the end portions. This option may require insulation between them and other weld joints, as they will be squeezed together.

[0079] In light of the above, it will be recognized that Figure 7 The winding arrangement has the same as Figure 4 Many of the same characteristics. For example, Figure 7 The winding arrangement can be considered as a winding in which the straight portions are arranged in layers in the slots, wherein these layers comprise a total number of layers, including at least two inner layers, at least two outer layers, and two intermediate layers located between the inner and outer layers. In such an embodiment, most of the first end turns and most of the second end turns have a common pitch (CP), most of the first end turns of the straight portions connecting the two intermediate layers have a pitch of CP+1, and most of the second end turns of the straight portions connecting the two intermediate layers have a pitch of CP-1. However, compared with... Figure 4 The arrangement differs, and the connection between the end portions associated with the bridging end wire turns is in... Figure 7 There is no radial alignment in the winding arrangement.

[0080] Alternative implementation methods

[0081] While embodiments of the winding arrangement have been disclosed herein, it will be appreciated that other embodiments are possible. For example, although the winding arrangement disclosed herein has been described in conjunction with segmented conductors having welded end loops at the connection ends, in at least some embodiments, the winding arrangement can be formed using continuous conductor segments (e.g., the entire path A for a given phase can be formed using a single continuous conductor). In this case, different twists can be formed in the end loops using an end loop forming machine. An asymmetric twist end loop would be an asymmetric end loop without intermediate welds.

[0082] As another example, in at least one embodiment, the winding is configured to have a CP+1 end loop and the CP-1 end loop is not associated with two intermediate adjacent layers, but rather with two inner adjacent layers or two outer adjacent layers.

[0083] As another example of an alternative implementation, the winding arrangement may have a different number of slots per pole per phase or a different number of conductor layers than those disclosed herein. For example, regarding the number of slots per phase per pole, there may be three (3) slots per phase per pole. In this case, the common pitch (CP) of most layers will be nine (9), while the other two common pitches (CP+1 and CP-1) will be ten (10) and eleven (11). As another example, there may be four (4) slots per phase per pole, and the common pitch of most layers will be twelve (12), while the other two common pitches will be eleven (11) and thirteen (13). Similarly, there may be five (5) or six (6) slots per phase per pole. Regarding the number of conductor layers, there may be ten (10) conductors per slot or fourteen (14) conductors per slot, or any other number of layers (L), where L / 2 = an odd number.

[0084] Various insulation arrangements are also possible for the windings disclosed herein. For half-full-half-phase bands, every other slot accommodates half a conductor from one phase and a semiconductor from the other phase (and the intermediate slots accommodate only conductors for one phase). Designs with intermediate layers in the end loops having CP+1 and CP-1 pitches are particularly advantageous, as this ultimately results in a design that accommodates half an outer layer of one phase and half an inner conductor of the other phase every other slot. Thus, the two phases are in contact with each other only in one location, between the inner and outer halves. Additional insulation material (e.g., NOM paper) may be required between the phases, so this design will have only one area for insulation material. The insulation material can be two tubes or a slot liner with a B-shape, where the upper half of the B surrounds half a conductor in the slot, and the lower half surrounds the inner conductor of the slot.

[0085] In at least one implementation, for the most common pitch (CP) lIn a layer, some (or all) of the end circuits can be upper and lower end circuits, where at least one end circuit overlaps at least one other end circuit. In this case, the average pitch of the end circuits is equal to the common pitch. For example, two (2) slots per phase per pole of a motor can allow a seven (7) pitch end circuit to overlap a five (5) pitch end circuit. In this case, the average pitch is six (6), i.e., the common pitch (CP1). This embodiment also applies to special two-layer structures. For example, intermediate layers 3 and 4 have a common pitch of 5 at the crown end. However, this layer may have upper and lower end circuits, where the upper pitch is six (6) and the lower pitch is four (4).

[0086] While various implementations have been provided herein, those skilled in the art will understand that other implementations and modifications are possible. Furthermore, aspects of the various implementations described herein can be combined with or substituted with aspects from other features to achieve implementations different from those described herein. Therefore, it should be understood that the various features and functions disclosed above and others, or alternatives thereof, can be voluntarily combined into many other different systems or applications. Those skilled in the art can subsequently make various substitutions, modifications, variations, or improvements therein, which are also intended to be covered by any final appended claims.

Claims

1. A stator for an electric motor, comprising: A stator core comprising a plurality of teeth defining a plurality of slots, the stator core having a first axial end and a second axial end opposite to the first axial end; as well as A winding located on the stator core, the winding including a plurality of parallel paths for each phase of the winding, each parallel path including (i) a plurality of first end loops disposed on the first axial end of the stator core, (ii) a plurality of conductors extending through the slot and (iii) a plurality of second end loops disposed on the second axial end of the stator core; The plurality of conductors are arranged in layers within the groove, wherein the layers comprise a total number L, and each layer includes at least two inner layers, two intermediate layers, and at least two outer layers, where L / 2 is an odd integer; and The first end loop and the second end loop define a common pitch CP, and the first end loop and the second end loop associated with the intermediate layer alternate between having a pitch equal to CP+1 at the first axial end and having a pitch equal to CP-1 at the second axial end.

2. The stator of claim 1, wherein, The common pitch CP is defined by the first end loop and the second end loop associated with the at least two inner layers and the at least two outer layers.

3. The stator of claim 2, wherein, The bridging loop connecting one conductor of the two intermediate layers to one conductor of the non-intermediate layer has a pitch equal to CP.

4. The stator of claim 1, wherein, The layer includes a first semi-continuous layer and a second semi-continuous layer, wherein the conductor in the first semi-continuous layer of the slot group moves to the left of the conductor in the second semi-continuous layer by one slot.

5. The stator of claim 1, wherein, The winding includes a plurality of segmented conductors connected together to form the winding, each segmented conductor including (i) an end loop disposed on the crown end of the stator core, (ii) two branches extending through the slot, and (iii) two branch ends extending from the slot at the connecting end of the stator core; Each branch end extending from each layer of the groove has a common torsion associated with the layer from which the branch end extends, wherein the common torsion is equal to the number of grooves torsion at the branch end; The common torsion associated with at least half of the layers is the first torsion; and The common torsion associated with at least one of the layers is a second torsion that is different from the first torsion.

6. The stator of claim 5, wherein, The at least one of the layers is part of a group of remaining layers other than the at least half of the layers.

7. The stator of claim 6, wherein, The at least half of the layer is exactly half of the layer, at least two of the remaining layers are associated with the second torsion degree, and at least one of the remaining layers is associated with a third torsion degree, which is different from the first torsion degree and the second torsion degree.

8. The stator according to claim 6, wherein, The at least half of the layer is more than half of the layer, and at least two of the remaining layers are associated with the second torsion, and the second torsion includes an integer part and a fractional part.

9. The stator of claim 5, wherein, The at least one of the layers is a single layer, and the at least half of the layers comprises all layers other than the single layer.

10. The stator of claim 5, wherein, Each branch end also includes an end portion, and the paired end portions are joined together at the connecting end of the stator core to form an end loop at the connecting end of the winding.

11. The stator of claim 10, wherein, The end portions associated with the bridging end circuit of the winding are aligned in the radial direction.

12. The stator of claim 10, wherein, The end portion associated with the bridging end circuit of the winding is misaligned in the radial direction.

13. The stator of claim 10, wherein, Two common torsional degrees of a pair of branch ends associated with one of the paired end portions are combined to define the end loop pitch of the pair of branch ends at the connecting end of the core, wherein the layer comprises two inner layers, two intermediate layers and two outer layers, and wherein a first group of segmented conductors disposed in the two inner layers forms a first winding around the stator core, a second group of segmented conductors disposed in the two intermediate layers forms a second winding around the stator core, and a third group of segmented conductors disposed in the two outer layers forms a third winding around the stator core, and wherein a first bridging end loop provides a connection between the two inner layers and the two intermediate layers, and a second bridging end loop provides a connection between the two intermediate layers and the two outer layers.

14. The stator of claim 13, wherein, The first group of segmented conductors defines a common inner end loop pitch, the second group of segmented conductors defines a common middle end loop pitch, and the third group of segmented conductors defines a common outer end loop pitch, wherein the common inner end loop pitch is the same as the common outer end loop pitch, and wherein the difference between the common middle end loop pitch and the common inner end loop pitch is 1.

15. A stator for an electric motor, comprising: A stator core comprising a plurality of teeth defining a plurality of slots; as well as The winding located on the stator core includes a plurality of conductors connected together to provide a plurality of parallel paths for each phase, each phase having a half-full-half phase band, the winding further including (i) a plurality of first end turns disposed at a first end of the stator core, (ii) a straight portion extending through the slot and (iii) a plurality of second end turns disposed at a second end of the stator core; The straight portion is arranged in layers within the slot, wherein each layer comprises a total number L, where L is greater than 5 and L / 2 is an odd integer. Each layer includes at least two inner layers, two intermediate layers, and at least two outer layers. A plurality of first conductor portions are disposed in the at least two inner layers to form a plurality of first windings around the stator core; a plurality of second conductor portions are disposed in the two intermediate layers to form a plurality of second windings around the stator core; and a plurality of third conductor portions are disposed in the at least two outer layers to form a plurality of third windings around the stator core. The plurality of first conductor portions define a common inner end loop pitch at the second end of the stator core, the plurality of second conductor portions define a common middle end loop pitch at the second end of the stator core, and the plurality of third conductor portions define a common outer end loop pitch at the second end of the stator core, wherein the common inner end loop pitch is the same as the common outer end loop pitch, and wherein the difference between the common middle end loop pitch and the common inner end loop pitch is 1.

16. The stator of claim 15, wherein, Each straight section is connected to a branch end extending from each layer at the second end, and has a common torsion associated with the layer from which the branch end extends, the common torsion being equal to the number of grooves twisted by the branch end.

17. The stator of claim 16, wherein, The common torsion associated with the at least two inner layers is a first common torsion, the common torsion associated with the two intermediate layers is a second common torsion, and the common torsion associated with the at least two outer layers is a third common torsion.

18. The stator of claim 17, wherein, The first common torsion degree is the same as the third common torsion degree, and the second common torsion degree is different from the first common torsion degree.

19. The stator of claim 15, wherein, The first end of the stator core is a crown end, the second end of the stator core is a connecting end, and the plurality of conductors are segmented conductors, each segmented conductor comprising: (i) an end coil disposed on the connecting end of the stator core, (ii) two straight portions extending through the slot, and (iii) two branch ends extending from the slot on the connecting end of the stator core, each branch end having a common torsion associated with a layer extending therefrom, the common torsion being equal to the number of slots tortuous by the branch end.

20. A stator for an electric motor, comprising: A stator core comprising a plurality of teeth defining a plurality of slots; as well as The winding located on the stator core includes a plurality of conductors connected together to provide a plurality of parallel paths for each phase, and the winding further includes (i) a plurality of first end turns disposed at a first end of the stator core, (ii) a straight portion extending through the slot and (iii) a plurality of second turns disposed at a second end of the stator core. The straight portion is arranged in layers within the groove, each layer comprising at least two inner layers, at least two outer layers, and two intermediate layers located between the inner and outer layers. Most of the first end turns and most of the second end turns have a common pitch CP, most of the first end turns of the straight portion connecting the two intermediate layers have a pitch of CP+1, and most of the second end turns of the straight portion connecting the two intermediate layers have a pitch of CP-1.

Images