Stator with outer diameter busbar connection

Abstract

A stator for an electric machine includes a cylindrical core defining an inner cylindrical surface and an outer cylindrical surface with a plurality of slots formed between the inner cylindrical surface and the outer cylindrical surface. A winding is positioned on the cylindrical core. Leads of the winding include a plurality of inner leads associated with conductors in an inner layer of the slots and a plurality of outer leads associated with conductors in an outer layer of the slots. A busbar assembly includes a plurality of inner busbars connected to the plurality of inner leads and a plurality of outer busbars connected to the plurality of outer leads. The plurality of outer busbars are positioned radially outward from end turns of the winding and radially inward from the outer cylindrical surface.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 221,720, filed July 14, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of electric motors, and more specifically to winding structures and terminal connections for electric motors. Background Technology

[0004] Electric motors are designed to meet specific operational requirements and space constraints. Examples of design features that benefit operational performance include stator size, rotor size, type and arrangement of windings, and any other design parameters that a person skilled in the art will recognize. All operational requirements of the motor must be met, while also satisfying certain space constraints depending on the motor application. For vehicle applications, space in the engine compartment is limited, and designers must consider the overall diameter and length of the motor. Therefore, it is important to limit the size of the motor without sacrificing performance characteristics.

[0005] The motor stator includes windings positioned on the stator core. The windings include conductors extending through slots in the stator core, end turns extending between the conductors in the slots, and multiple leads extending from some of the conductors within the slots. These stators typically require busbars with copper rails that make connections at the leads to accomplish one or more of the following: (i) connecting parallel leads, (ii) creating a neutral point for the winding configuration, (iii) guiding phase leads to the inverter connection points, and (iv) connecting leads to create series connections for the winding paths. All these connections tend to compete for the same space. Therefore, the busbar can become quite high in the axial direction (i.e., defined by an axis extending through the center of the stator core), extending beyond the end turns of the windings.

[0006] Given the above, it can be difficult to properly encapsulate the stator and busbar assemblies within the limited space of a vehicle's engine compartment. This problem is exacerbated when more leads are associated with the windings due to an increase in the number of slots per phase per pole, the number of parallel conductors per phase, or the number of phases. This problem is particularly acute for stators that require series connections between winding paths and require a larger number of slots per phase per pole (e.g., three or four).

[0007] In view of the foregoing, it is desirable to provide a stator for an electric motor having an optional busbar configuration that results in a reduction in stator length, particularly a stator with an increased number of slots per phase per pole of windings, an increased number of parallel conductors per phase, an increased number of phases, an increased number of series connections, and / or a larger number of slots per phase per pole. It would be even more advantageous if such a stator could be easily manufactured, thereby reducing manufacturing time and cost. While the stator intended to be provided offers one or more of these or other advantageous features that are obvious to those reading this disclosure, the teachings disclosed herein extend to embodiments falling within the scope of the appended claims, regardless of whether they achieve one or more of the aforementioned advantages. Summary of the Invention

[0008] According to at least one embodiment of this disclosure, a stator for an electric motor includes a cylindrical core, windings, and a busbar assembly. The cylindrical core defines an inner cylindrical surface and an outer cylindrical surface, wherein a plurality of slots are formed between the inner and outer cylindrical surfaces. The windings are positioned on the cylindrical core. The windings include slot-in-slot portions extending through the slots, end turns, and leads. The leads of the windings include a plurality of inner leads associated with conductors in the inner layer of the slots and a plurality of outer leads associated with conductors in the outer layer of the slots. The busbar assembly includes a plurality of inner busbars connected to the plurality of inner leads, and a plurality of outer busbars connected to the plurality of outer leads. The plurality of outer busbars are radially outwardly positioned from the end turns of the windings and radially inwardly positioned from the outer cylindrical surface.

[0009] According to another embodiment of this disclosure, a stator for an electric motor includes: a core defining a plurality of slots; and a winding positioned on the core, the winding including an inner slot portion, end turns, and leads, the leads of the winding including a plurality of inner leads associated with conductors in the inner layer of the slot and a plurality of outer leads associated with conductors in the outer layer of the slot. The stator also includes a busbar assembly including a plurality of inner busbars and a plurality of outer busbars held by a support. The plurality of inner busbars are connected to the plurality of inner leads, and the plurality of outer busbars are connected to the plurality of outer leads. The plurality of inner busbars are axially positioned outward from the ends of the end turns. The plurality of outer busbars are radially positioned outward from the ends of the end turns and axially positioned inward from the ends of the end turns.

[0010] According to another embodiment of this disclosure, a busbar assembly includes a plurality of inner busbars, each inner busbar including a plurality of connecting strips and a neutral connecting strip. Each inner busbar includes a circumferential portion and a plurality of axial connecting arms. The busbar assembly also includes a first support member engaging with each inner busbar, the first support member including a first non-conductive arcuate portion. Additionally, the busbar assembly includes a plurality of external busbars radially outwardly positioned from the plurality of inner busbars, each external busbar including a circumferential portion extending between two axial connecting arms. The busbar assembly also includes a second support member engaging with each external busbar, the second support member including a second non-conductive arcuate portion, and at least one axial branch extending from the second non-conductive arcuate portion. A neutral connecting strip is positioned between the first support member and the second support member.

[0011] The features and advantages described above, as well as other features and advantages, will become more apparent to those skilled in the art upon reference to the following detailed description and accompanying drawings. Attached Figure Description

[0012] Figure 1 This is a perspective view of the stator, which includes a stator core and a two-part busbar assembly providing outer diameter series connectors and inner diameter phase connectors for stator windings;

[0013] Figure 2 It was separated from the stator core. Figure 1 A perspective view of a busbar assembly, which includes two housing parts and multiple busbars embedded in the housing;

[0014] Figure 3 yes Figure 2 A perspective view of the outer diameter busbar and inner diameter busbar of the busbar assembly, the busbars being shown in association with the stator windings but separately from the housing of the busbar assembly;

[0015] Figure 4 yes Figure 3 Side view of the busbars and stator windings;

[0016] Figure 5 yes Figure 2 A perspective view of the outer diameter busbar of the busbar assembly, with the outer diameter busbar shown separately from the housing of the busbar assembly;

[0017] Figure 6 yes Figure 1 A perspective view of an alternative embodiment of the busbar assembly, showing an outer diameter busbar and an inner diameter busbar, the busbars being shown in association with the stator windings but separated from the housing of the busbar assembly;

[0018] Figure 7 yes Figure 6 Axial end view of the busbar;

[0019] Figure 8 yes Figure 7 An axial end view of an alternative embodiment of the busbar; and

[0020] Figure 9 yes Figure 7 An axial end view of another alternative embodiment of the busbar. Detailed Implementation

[0021] Reference Figure 1 The motor includes a stator 12 having a busbar assembly 40 positioned thereon. The stator 12 includes a stator core 14, on which a winding configuration 30 is positioned. A rotor of the motor (not shown) is configured to be rotatably mounted within the core 14. The winding configuration 30 includes a plurality of phase windings, each phase winding terminating at one of a plurality of leads 36. The busbar assembly 40 is disposed at one end of the stator assembly 12 and electrically connected to the winding leads 36. As described herein, the busbar assembly 40 is positioned axially and radially outward from the end turns 34 of the winding configuration 30. Simultaneously, the busbar assembly 40 is also positioned radially inward from the outer diameter of the stator core (i.e., within a cylindrical space defined by the stator core and extending axially beyond the ends of the stator core).

[0022] Stator core and windings

[0023] Continue to refer to Figure 1 The stator core 14 is made of a ferromagnetic material and is typically formed from multiple steel plates that are stamped and stacked on top of each other to form a lamination stack. The stator core 14 is generally cylindrical in shape, defined by a central axis 20, and includes a cylindrical inner circumferential surface 22 and a cylindrical outer circumferential surface 24. The inner circumferential surface 22 defines the inner diameter (ID) of the stator assembly 12 (which may also be referred to herein as the inner cylindrical surface). The outer circumferential surface 24 defines the outer diameter (OD) of the stator assembly 12 (which may also be referred to herein as the inner cylindrical surface). A plurality of teeth 16 are formed inside the stator core 14 and point inward toward the central axis 20. Each tooth 16 extends radially inward and terminates at the inner circumferential surface 22. Axial grooves 18 are formed between the teeth 16 of the stator core 14.

[0024] The slots 18 defined by the teeth 16 may be open along the inner circumferential surface 22 of the stator core 14, or may be semi-closed slots, wherein the width of each slot 18 near the inner circumferential surface 22 is smaller than its width near the outer circumferential surface 24. Openings to the slots 18 are provided through the inner circumferential surface and through both ends of the stator core 14. Each slot 18 is defined between adjacent teeth 16, with two adjacent teeth forming two opposing radial walls for a slot. Since the slots 18 are radially inwardly positioned on the stator core 14, there are no slots 18 on the exterior of the stator core. A shoulder 19 is formed at each end of the stator between the outer circumferential surface 24 and the slot.

[0025] The stator core 14 is configured to hold the winding configuration 30 (which may also be referred to herein as a “winding”) within slots 18 of the stator core 14. In at least one embodiment, the winding configuration 30 is formed by a plurality of elongated conductors (e.g., copper conductors) continuously wound within the slots 18 of the stator core 14 to form the winding. In at least one alternative embodiment, as those skilled in the art will recognize, the winding configuration 30 is formed by a plurality of segmented conductors (e.g., copper conductor segments, which are sometimes referred to as “hairpin” or “U-turn” conductors). The segmented conductors are inserted into the slots 18 from a first end 26 (e.g., an “insertion end”) of the stator core 14. The segmented conductors are joined together at opposite ends 28 (e.g., “weld ends”) of the stator core 14.

[0026] The conductors of the completed winding configuration 30 form multiple phase windings. In at least one embodiment, the winding configuration includes three phase windings (e.g., a U-phase winding, a V-phase winding, and a W-phase winding), wherein each phase has multiple paths. Depending on the desired winding configuration, the three phase windings may be star (“Y”) or delta (“Δ”) connected.

[0027] The conductor of the completed winding 30 formed on the stator core includes slot portions 32, end turns 34, and winding leads 36. The slot portions 32 are straight portions of conductors extending through slots 18 of the stator core 14. Each slot portion 32 carries current from one end 26 / 28 of the stator core 14 to the opposite end 28 / 26 of the stator core. As those skilled in the art will appreciate, the slot portions 32 may be aligned in a single row within each slot, and each position in that row may be referred to as a conductor “layer.” For example, each slot 18 may include four, six, eight, or some other number of conductor layers arranged in a single row from the innermost to the outermost layer.

[0028] Continue to refer to Figure 1The end coil 34 connects the slot portion of the winding. Specifically, each end coil 34 connects one slot portion in the first slot to another slot portion in the second slot. The number of slots spanned by the end coil defines the "pitch" of the end coil (e.g., five, six, seven pitch, etc.). When the winding is formed of segmented conductors, the end coil 34 includes a bent portion (also called a "U-shaped coil") disposed on the insertion end of the core and a welded portion on the connecting end (also called a "welded end") of the stator core. In this case, each segmented conductor includes a first branch extending through one slot, a second branch extending through another slot, and a U-shaped coil extending between the two branches. The U-shaped coil provides the end coil 34a at the insertion end 26 of the core 14. The branch ends extending from the connecting end 28 of the stator are bent to form adjacent branch ends. Adjacent branch ends are welded or otherwise joined together to form the end coil 34b on the connecting end 28 of the stator core.

[0029] The winding 30 and stator core 14 define various stator dimensions. For example, the cylindrical shape of the stator core 14 can be defined by OD and ID. Additionally, the axial length of the stator core 14 is defined by the distance between the axially facing surfaces at the connecting ends and the opposing axially facing surfaces at the welding ends. Regarding the winding 30, since the end turns 34 of the winding extend beyond the stator core 14 in the axial direction, the axial length of the winding 30 is greater than that of the stator core 14. The axial length of the winding 30 can be defined by the distance between the ends of the end turns 34 at opposite ends 26, 28 of the stator core 14. The “end” of the end turn 34 can be considered as the outermost point / region on the end circuit axially from the stator core 14. If the ends of the end turns 34 on each side of the stator are considered to lie in a single plane, the axial length of the winding 30 can be defined as the distance between these two planes. Additionally, winding 30 has a width w defined between the inner conductor extending from the innermost layer of the stator slot 18 and the outer conductor extending from the outermost layer of the stator slot. End turns 34 are also defined by the same width w, as shown below. Figure 1 As shown. Since the end coil 34 is arranged in a circular manner around the stator core, the outer conductor can be considered to define the outer diameter 31 of the end coil 34, and the inner conductor can be considered to define the inner diameter 29 of the end coil 34. The width of the end coil is the distance between the outer diameter 31 and the inner diameter 29.

[0030] Winding lead 36 is a conductor portion (e.g., a branch end) extending axially beyond the end of end turn 34. Each conductor forming winding lead 36 is connected to a slotted portion of the winding and extends outward from end turn 34. For example, as in Figure 4 and Figure 5As best shown, each winding lead 36 extends slightly beyond the end coil 34 in the axial direction. In at least some embodiments, the winding lead 36 is a bent conductor (e.g., in a manner similar to branch ends forming adjacent branch ends for welding together) and thus has a radial or circumferential component. In other embodiments, one or more winding leads 36 may be unbent branch ends extending directly out of the slots of the stator core 16 in the axial direction. In any case, each winding lead 36 extends away from the slot and terminates at an end. As explained in more detail below, the end of each lead 36 is coupled to one of the busbars of the busbar assembly 40. It will be appreciated that the connection between the lead 36 and the busbar 42 can take any of a variety of forms, such as brazing or welding (e.g., tungsten inert gas (TIG) welding).

[0031] The winding 30 in the embodiments disclosed herein includes a relatively large number of leads 36. As previously stated, the relatively large number of leads is due to the construction of the winding 30, for example, a three-phase winding with a relatively large number of slots per phase per pole, each phase including multiple paths, and multiple series connectors extending between the multiple paths in each phase. Figure 1 , Figure 4 and Figure 5 The winding configuration shows a total of thirty-six leads 36.

[0032] Leads 36 include a set of inner leads 37 extending from the innermost layer of the winding and a set of outer leads 38 extending from the outermost layer of the winding. Both inner leads 37 and outer leads 38 are located on the same end of the stator core as the busbar assembly (i.e., welded end 28). Inner leads 37 include phase connection leads for the stator winding 30 (e.g., leads for the U, V, and W phases in a three-phase winding configuration) and a neutral lead. Outer leads 38 are all winding path leads connecting various winding paths (e.g., leads for a series connection between two winding paths such that the connection between the two winding paths provides a longer winding path). An example of such a stator with inner and outer winding leads is shown in U.S. Patent Application Publication No. US-2020-0244125, published July 30, 2020, the contents of which are incorporated herein by reference in their entirety.

[0033] busbar components

[0034] Now, especially referencing Figure 2Busbar assembly 40 is shown separately from stator assembly 12. Busbar assembly 40 includes a plurality of conductive busbars 42 held by a non-conductive support 48 (which may alternatively be referred to as a “body” or “mount”). Busbars 42 include inner busbars 44 and outer busbars 46. In the embodiments disclosed herein, support 48 is a two-part structure comprising a non-conductive inner busbar support 50 that holds the inner busbars 44 and a non-conductive outer busbar support 60 that holds the outer busbars 46. As used herein, the terms “non-conductive” or “insulating” refer to an article made of a material that is not easily conductive, such as plastics / polymers, glass, ceramics, rubber, or any of a variety of other materials that will be recognized by those skilled in the art. Conversely, as used herein, the term “conductive” refers to an article made of a material that is easily conductive, such as copper, silver, aluminum, gold, or any of a variety of other materials that will be recognized by those skilled in the art.

[0035] Internal busbar support

[0036] The inner busbar support 50 is made of a non-conductive material. The inner busbar support 50 is generally semi-circular in shape and includes an arcuate portion 52 defining a plurality of channels for the inner busbar 44. The arcuate portion 52 is defined by a semi-circular shape concentric with the circular cross-sectional shape of the stator core 14. The arcuate portion 52 includes a circumferential sidewall 54 defining the periphery of the arcuate portion 52, a first facet (not shown) facing axially inward, and an opposing second facet (such as...) facing axially outward. Figure 2 (As shown).

[0037] Multiple terminal bridges 56 are positioned on the second face and extend axially outward over the support 50. Specifically, each terminal bridge 56 extends outward on the second face and provides a platform, such that space is defined below each platform (i.e., axially inward from each platform). A platform hole 58 is defined on each terminal bridge 56 near the center of the associated platform. As explained in more detail below, each terminal bridge 56 is configured to support the terminal plate 72 of the phase connector 70 and allow the phase terminal post (not shown) to extend through the platform hole 58 and extend below the associated platform. In at least some embodiments, a terminal nut 71 (see...) Figure 3 It is positioned below each terminal bridge 56 and is configured for threaded engagement with the terminal post.

[0038] The inner busbar support 50 also includes at least one mounting hole 59. Figure 2In one embodiment, mounting hole 59 is located on one end of arcuate portion 52 and extends through arcuate portion 52, thereby providing a passage from the first facet to the second facet. As explained in more detail below, mounting hole 59 is configured to receive a post or other protrusion extending from foreign flow strip support 60 and to allow inner flow strip support 50 to be coupled to foreign flow strip support 60.

[0039] Internal busbar

[0040] The inner busbar 44 is entirely held and / or engaged with the inner busbar support 50. The inner busbar 44 includes a plurality of connecting strips 70 and neutral connecting strips 78 (the neutral connecting strips 78 are in...). Figure 3 (Best shown in the middle). Each inner busbar 44, including the phase connector 70 and the neutral connector 78, is made of conductive material. As described below and as... Figures 1 to 5 As shown, all inner busbars 44 are axially positioned outward from the end of the end coil 34 and radially positioned inward from the outer diameter 31 defined by the end coil.

[0041] like Figure 2 and Figure 3 As shown, the busbar assembly 40 disclosed herein includes three distinct phase connectors 70, one of which is associated with each phase of the three-phase winding. Each phase connector 70 includes a terminal plate 72, a circumferential extension 74, and a plurality of axial connecting arms 76 (which may also be referred to herein as “axial arms”).

[0042] Each terminal plate 72 is generally flat and has a rectangular shape. Each terminal plate 72 is configured to engage and rest on the platform of one of the terminal bridges 56 of the inner support 50. The terminal plate 72 includes holes that are similarly sized and aligned with the center holes 58 of the associated terminal bridges 56. As previously described, due to the space provided below the terminal bridges 56, phase terminals (e.g., bolts or similar structures) can pass through the holes in the terminal plate 72 and the associated center holes 58 of the bridges, thereby allowing the terminals to be connected to the phase connector 70.

[0043] The circumferential extension 74 of the connecting strip 70 is a generally flat and elongated member that connects the terminal plate 72 to the axial arm 76. The circumferential extension 74 is held within a channel of the inner busbar support 50. For this purpose, the electrically insulating material (e.g., polymer or other material) forming the inner busbar support 50 can be molded around the circumferential extension or otherwise formed during the manufacture of the busbar assembly 40. Thus, the busbar support 50 and the connecting strip 70 are made as a single unit, wherein the individual connecting strips 70 may not be removable from the busbar support 50 without damaging the support 50. In at least one alternative embodiment, after the connecting strip 70 is engaged with the busbar support 50, the busbar support 50 is overmolded with plastic to provide insulation for the connecting strip 70 near the point of engagement with the inner busbar support 50.

[0044] Each phase connector 70 has an axial arm 76 extending away from the circumferential extension 74. Each axial arm 76 includes a proximal end connected to the circumferential extension 74 and a distal end configured for connection to a phase lead. While the proximal end of the axial arm 76 may have a radial component, the distal end of the axial arm 76 extends axially away from the circumferential extension 74. The distal ends of the axial arms 76 are pin-shaped structures having a cross-sectional size and shape similar to that of the winding lead 36, and are similarly spaced. Thus, the distal ends of the axial arms 76 can be positioned adjacent to the inner lead 37, allowing for easy welding or other connections between the axial arms 76 and the inner lead 37. Although the axial arms 76 are shown and described herein as pin-shaped members arranged in a row, each pin member having a generally rectangular cross-sectional shape, it should be appreciated that the axial arms 76 can alternatively be configured in other forms, shapes, and arrangements.

[0045] As in Figure 3 As best shown, the neutral connecting strip 78 includes a circumferential extension 80 and a plurality of axial connecting arms 82 (which may also be referred to herein as "axial arms"). The circumferential extension 80 of the neutral connecting strip 78 is a generally flat and elongated member, wherein the plurality of axial arms 82 extend from the inside of the strip. The circumferential extension is sandwiched or otherwise positioned between the inner busbar support 50 and the outer busbar support 60. For example, in at least one embodiment, the inner busbar support 50 includes a channel for retaining the circumferential extension 80. In at least one alternative embodiment, the circumferential extension 80 engages with both the inner busbar support 50 and the outer busbar support 60.

[0046] Axial arms 82 extend away from the circumferential extension 80 of the neutral connecting bar 78. Each axial arm 82 includes a proximal end connected to the circumferential extension 80 and a distal end configured for connection to the neutral lead. While the proximal end of the axial arm 82 may have a radial component, the distal end of the axial arm 82 extends axially away from the circumferential extension 80. The distal ends of the axial arms 82 are pin-shaped structures having a cross-sectional size and shape similar to those of the winding lead 36, and are similarly spaced. Therefore, the distal ends of the axial arms 82 can be positioned adjacent to the inner lead 37, allowing for easy welding or other connections between the axial arms 82 and the inner lead 37.

[0047] Foreign exchange flow support

[0048] The foreign exchange flow support 60 is made of a non-conductive material. The foreign exchange flow support 60 is generally semi-circular in shape and includes an arc-shaped portion 62 from which multiple axial branches 68 extend.

[0049] The arcuate portion 62 is defined by a semi-circular shape concentric with the circular cross-sectional shape of the stator core 14. The arcuate portion 62 includes a circumferential sidewall 64 defining its periphery, a first facet (not shown) facing axially inward, and an opposing second facet (such as...) facing axially outward. Figure 2 (As shown). The first face of the arcuate portion 62 is generally flat and configured to engage / rest on the end of the end coil 34 at the welded end 28 of the stator core. Similarly, the first face of the arcuate portion 52 of the inner busbar support 50 is configured to engage / rest on the second face of the arcuate portion 62 of the outer busbar support 60. As previously described, the neutral connecting strip 78 is positioned between and / or held by the arcuate portions 52 of the inner busbar support 50 and 60 of the outer busbar support 60.

[0050] The arcuate portion 62 also includes a plurality of holes 66 that provide passageways through the foreign exchange flow strip support 60 from the first facet to the opposite second facet. Each hole 66 is designed and sized to receive the end of the foreign exchange flow strip 46 and the outer lead 38. The holes 66 are arranged close to the sidewall 64 in a uniformly spaced manner, so that the similarly spaced outer leads 38 can be easily inserted through the holes without additional bending of the leads 38. Once the outer leads 38 are inserted through the holes, each outer lead 38 is adjacent to the end of the foreign exchange flow strip 46, so that welding or other connections can be easily made between each adjacent outer lead and the end of the flow strip.

[0051] The foreign exchange flow support 60 also includes at least one mounting post 63. Figure 2In one embodiment, the mounting post 63 is positioned on one end of the arcuate portion 62 and extends axially outward from the arcuate portion. For example... Figure 2 As shown, the mounting post 63 is designed and sized to pass completely through the mounting hole 59 on the inner busbar support 50. Therefore, the inner busbar support 50 is engaged with and held in place by the engagement of the mounting post 63 with the mounting hole 59. In at least some embodiments, the post 63 may be heat-fused, welded, or otherwise deformed to permanently secure the inner busbar support 50 to the outer busbar support 60. After the post 63 is deformed, the first busbar support 50 and the second busbar support 60 become a single unit, wherein the two supports may not be removable from each other without damaging the busbar assembly 40.

[0052] An axial branch 68 of the external flow bar support 60 is integrally formed with the arcuate portion 62 along the sidewall 64 and extends downward (i.e., axially inward) from the arcuate portion 62. The branch 68 is substantially solid but includes a plurality of holes 67 formed therein. The holes 67 provide a passage for the external flow bar 46 to pass through the branch 68. The length of each axial branch 68 is substantially equal to the height of the end coil 34 of the winding configuration 30. Therefore, when the first face of the arcuate portion 62 engages with the end of the end coil 34, the branch 68 of the external flow bar support has a length sufficient to abut against the shoulder 19 of the stator core 14. Figure 1 As shown, all branches 68 can be connected by legs 69 extending along the shoulder 19 of the stator core 14 between branches 68.

[0053] In addition to the holes 67 in branch 68, similar holes are provided in the arcuate portion 62. It will be appreciated that these holes 67, along with branch 68, are all arranged in a spaced-out relationship, thus providing associated gaps between the series connectors (i.e., the foreign exchange flow bars 46). These gaps advantageously allow for oil or air cooling of the windings in the areas of the series connectors / busbars 46 and the foreign exchange flow bar support 60.

[0054] Foreign exchange flow

[0055] All foreign exchange flow bars 46 are held by foreign exchange flow bar supports 60. In the disclosed embodiment, all foreign exchange flow bars 46 are series-connected bars formed by conductor segments having two ends. As described below and as... Figures 1 to 5 As shown, all the foreign exchange flow bars 46 are radially outward from the end coil 34, radially inward from the outer diameter 24 of the stator core, and axially inward from the end of the end coil 34.

[0056] Each external lead strip 46 is made of a conductive material, and in at least one embodiment, each external lead strip 46 is composed of a conductor segment having the same cross-sectional shape and size as the insulated copper conductor used to form the winding 30. The conductor segment is also coated with an insulating material, such as polyester, amide-imide, or PEEK. Similar to the branch ends of the U-shaped conductor used to form the winding 30, the ends of the conductors used for the external lead strip 46 are also trimmed to expose the conductive material, so that the ends can be easily connected to the outer leads 38 of the winding 30.

[0057] like Figures 1 to 5 As shown, each external lead 46 is provided by a U-shaped conductor segment 90, which has a first end 92 extending in the axial direction, a first radially outward bend 93 connected to the first end, a second end 94 extending in the axial direction, a second radially outward bend 95 connected to the second end, and an elongated circumferential portion 96 extending in the circumferential direction between the first bend 93 and the second bend 95. The first end 92 and the second end 94 of each conductor segment 90 extend in the axial direction (i.e., parallel to the central axis 20 defined by the stator core) and are therefore configured to align with the outer leads 38 of the winding 30. The radially outward bends 93, 95 transition the shape of each external lead 46 from the axial direction to the radial direction (i.e., perpendicular to the central axis 20 of the stator core and extending away from the winding 30). Then, the elongated circumferential portion 96 extends in the circumferential direction between the radially outward bending portions 93 and 95 (i.e., perpendicular to the axial direction and concentric / aligned with the inner diameter of the stator core).

[0058] It will be appreciated that the structure of each foreign exchange strip 46 is simple and involves a single-length conductor extending between two ends 92, 94. These two ends 92, 94 are used to connect to two external leads 38 from different paths of winding 30. Thus, each foreign exchange strip 46 serves to provide a series connection between two winding paths.

[0059] As described above, the ends 92, 94 of the external lead 46 are pin-shaped structures with cross-sectional dimensions and shapes similar to those of the external lead 38 of the winding 30. Therefore, the ends 92, 94 can be easily positioned adjacent to the external lead 38, which facilitates the connection of the ends 92, 94 to the external lead 38 (e.g., by welding or similar connection).

[0060] Although each U-shaped conductor segment 90 has a similar shape, it will be recognized that these shapes are not exactly the same. Specifically, while the axial lengths of the first end 92 and the second end 94 on a busbar are the same, the axial lengths of the first end 92 and the second end 94 on different busbars are different. For example, as... Figure 5As shown, the axial lengths of the first end 92 and the second end 94 of the first conductor segment 90a are significantly shorter than the axial lengths of the first end and the second end of the ninth conductor segment 90j. This difference in axial length between the first and second ends allows each circumferential portion 96 to be arranged in different axial planes separated from each other, such that the circumferential portions 96 do not intersect or overlap on the busbar assembly 40. This also allows all circumferential portions 96 to be arranged axially on top of each other (or in other words, at the same radial distance from the outer diameter of the stator core). Furthermore, the lengths of the different circumferential portions 96 are not uniform because the different circumferential portions extend with different numbers of slots. For example, the circumferential length of the first conductor segment 90a is greater than the circumferential length of the ninth conductor segment 90j.

[0061] As mentioned earlier, the foreign exchange flow bars 46 are entirely maintained by the foreign exchange flow bar support members 60. Specifically, as Figure 1 and Figure 2 As shown, each conductor segment 90 extends through multiple channels in the busbar support 60, such that the U-shaped conductor segments are non-removably held within the busbar support 60. These channels include holes 66 through the ends 92, 94 of the busbar 46, and holes 67 in the branch 68 providing channels for the elongated circumferential portion 96. For this purpose, the electrically insulating material (e.g., polymer or other material) forming the busbar support 60 can be molded or otherwise formed around the respective portions of the conductor segments 90 during the manufacture of the busbar assembly 40. Thus, the busbar support 60 and the conductor segments 90 are made as a single unit, wherein the individual conductor segments 90 may not be removable from the busbar support 60 without damaging the support 60. Although the busbar support 60 is formed around a portion of the conductor segment 90 (e.g., at holes 66 and 67), it will be appreciated that the extension of the conductor segment is not surrounded by the busbar support 60, and thus allows oil or other cooling fluids to flow around the conductor segment 90 during stator operation, thereby providing effective cooling of the busbar assembly 40 and the associated winding 30.

[0062] Installation and Operation

[0063] Based on the foregoing description, it will be appreciated that the busbar assembly 40 is configured such that an inner busbar 44 and an outer busbar 46 are arranged on the stator 12, resulting in a reduced axial length and a reduced footprint for the stator. Specifically, the inner busbar 44 is axially positioned outward from the end of the end coil 34 and radially positioned inward from the outer diameter of the end coil 34. Simultaneously, the outer busbar 46 is axially positioned inward from the end of the end coil 34 and radially positioned outward from the outer diameter of the end coil. The inner busbar 44 is configured to connect to an inner lead 37 extending from the inner layer of the winding, the inner lead 37 comprising a phase lead and a neutral lead. The outer busbar 46 is configured to connect to an outer lead 38 extending from the outer layer of the winding, the outer lead 38 being a winding path lead.

[0064] The arrangement of the busbar assembly 40 on the stator also provides an improved support arrangement for the busbars. Specifically, when the busbar assembly 40 is arranged on the stator 12, the external busbar support 60 is configured to engage / rest on the end of the end coil 34 of the winding 30, and the inner busbar support 50 is configured to engage / rest on the external busbar support 60. Simultaneously, the axial branch 68 of the external busbar support 60 extends axially along the outer diameter of the end coil 34 and engages / rests on the shoulder 19 of the stator core 14. This provides enhanced stability to the busbar assembly when it is positioned on the stator 12. Furthermore, the entire busbar assembly 40, including the inner busbar support 50 and the external busbar support 60, does not extend radially beyond the outer diameter of the stator core. This results in a reduction in the size of the stator 12 and an improvement in the stability of the busbar assembly 40. Furthermore, since most of the busbar 42 is exposed within the busbar assembly 40, cooling fluid is allowed to flow between the busbars and maintain a reduced temperature in the stator windings.

[0065] Alternative implementation methods

[0066] Now refer to Figure 6 and Figure 7 This illustrates a first alternative embodiment of the foreign exchange flow strip 46. In this embodiment, the foreign exchange flow strip 46 is configured as a V-shaped conductor segment 100, with... Figures 1 to 5 The U-shaped conductor segment 90 shown is different. Each V-shaped conductor segment 100 includes a first end 102 extending in the axial direction, a radially outward first bend 103 connected to the first end 102, a second end 104 extending in the axial direction, a radially outward second bend 105 connected to the second end 104, and an elongated portion 106 extending axially and circumferentially between the first bend 103 and the second bend 105. The first end 102 and the second end 104 of each conductor segment 100 extend in the axial direction (i.e., parallel to the central axis 20 defined by the stator core) and are therefore configured to align with the outer leads 38 of the winding 30. The radially outward bends 103, 105 transition the shape of each external flow strip 46 from the axial direction to the radial direction (i.e., perpendicular to the central axis 20 of the stator core and extending away from the winding 30). The elongated portion 106 defines a generally V-shaped path extending between the radially outward bends 103, 105.

[0067] The path defined by the elongated portion 106 is typically defined by axial and circumferential components (i.e., generally parallel to the surface defined by the inner diameter of the core), but may also include additional radial components. Therefore, in addition to the bends defining the apex of the V-shape, the elongated portion 106 also includes one or more additional bends that adjust the path in some way. For example, Figure 6 The elongated portion 106 of the conductor segment 100a shown includes a first bend 110 that defines a small coil of wire downwards at approximately 30° (i.e., the defined path takes more axial coils at the bend 110). The conductor segment 100a also includes a second bend 112 that defines a coil of wire upwards at approximately 90° (i.e., the path changes from axially downward and circumferentially moving to axially upward and circumferentially moving at the bend 112; the bend also defines the apex of a V-shape). The conductor segment 100a also includes a third bend 114 and a fourth bend 116, the third bend 114 causing the path to move slightly radially inwards (i.e., toward the end coil 34), and the fourth bend 116 causing the path to continue on the previous axially upward and circumferential path. The remainder of the path in the elongated portion 106 is then held until the V-shaped portion joins to the second end 102.

[0068] Figure 7 It shows the positioning on the winding. Figure 6 The flow of cooling fluid is facilitated by the V-shaped conductors 100. As shown, the ends 102, 104 of the V-shaped conductors 100 are aligned with the outer leads 38, allowing for quick and easy connection between each end 102, 104 and one of the outer leads 38. As defined above, the elongated portion 106 is routed along a path that first moves axially downward, pivots at the apex, and then moves axially upward. Bending portions (e.g., 110, 112, 114, 116) route each elongated portion 106 in a manner that avoids other elongated portions of the V-shaped conductors, and some conductors are nested within other conductors (e.g., 110c nested within 110a). Due to the separation between the V-shaped conductors 100, cooling fluid is allowed to flow between each V-shaped conductor 100 during operation of the motor.

[0069] Although Figure 6 and Figure 7 Alternative constructions for foreign exchange flow line 46 are shown, but it will be appreciated that other alternative constructions are also conceived. For example, Figure 8 and Figure 9 It shows the relationship with Figure 6 The implementation is similar to two additional embodiments of the foreign exchange flow bar 46, and a similar series connection is formed between the outer leads, but... Figure 8 and Figure 9 Foreign exchange flow 46 in the text is shaped differently and includes [the following text is incomplete and likely refers to a different context: "with"] Figure 6 The different bends, bends, and over-under relationships between busbars allow for different nesting and overlapping configurations, and also facilitate different lead connections for different winding configurations.

[0070] The foregoing detailed description of one or more embodiments of a stator having an outer diameter busbar connector is presented herein by way of example only and not limitation. It will be appreciated that certain individual features and functions described herein have advantages that can be obtained without combining them with other features and functions described herein. Furthermore, it will be appreciated that various alternatives, modifications, variations, or improvements, or substitutions, of the disclosed embodiments and other features and functions can be combined as desired into many other different embodiments, systems, or applications. Those skilled in the art can subsequently make alternatives, modifications, variations, or improvements that are not currently foreseen or anticipated, and these are also intended to be covered by the appended claims. Therefore, the spirit and scope of any appended claims should not be limited to the description of the embodiments contained herein.

[0071] Various embodiments are presented in the accompanying drawings and description. Alternative embodiments and equivalents of this disclosure may be devised without departing from the spirit or scope of this disclosure. It should be noted that any discussion herein with reference to "one embodiment," "implementation," "exemplary embodiment," etc., indicates that the described embodiment may include specific features, structures, or characteristics, but such specific features, structures, or characteristics are not necessarily included in every embodiment. Furthermore, references to the foregoing do not necessarily include references to the same embodiments. Finally, whether explicitly described or not, it will be readily understood by those skilled in the art that each specific feature, structure, or characteristic of a given embodiment may be used in combination with those features, structures, or characteristics of any other embodiment discussed herein.

Claims

1. A stator for an electric motor, the stator comprising: A cylindrical core defining an inner cylindrical surface and an outer cylindrical surface, wherein a plurality of grooves are formed between the inner cylindrical surface and the outer cylindrical surface; A winding positioned on the cylindrical core, the winding including an inner portion extending through the slot, end turns and leads, the leads of the winding including a plurality of inner leads associated with a conductor in the inner layer of the slot and a plurality of outer leads associated with a conductor in the outer layer of the slot; as well as A busbar assembly includes a plurality of inner busbars and a plurality of outer busbars, the plurality of inner busbars being connected to a plurality of inner leads and the plurality of outer busbars being connected to a plurality of outer leads, wherein the plurality of outer busbars are radially outwardly positioned from the end turns of the winding and radially inwardly positioned from the outer cylindrical surface. The busbar assembly further includes a first support member made of a non-conductive material and a second support member made of a non-conductive material, wherein the first support member is different from the second support member, wherein at least some of the plurality of inner busbars extend through the first support member, and wherein at least some of the plurality of outer busbars extend through the second support member.

2. The stator according to claim 1, wherein the inner leads include a plurality of phase leads and a plurality of neutral leads, and wherein the outer leads include a plurality of winding path leads.

3. The stator of claim 2, wherein the inner busbar includes at least three phase connectors and at least one neutral connector connected to the phase leads, and wherein each outer busbar provides a series connector between two winding path leads.

4. The stator of claim 1, wherein the plurality of inner leads extend in an axial direction, and the inner busbar includes an axial connecting arm positioned adjacent to the inner leads, and wherein the plurality of outer leads extend in the axial direction, and the outer busbar includes an axial connecting arm positioned adjacent to the outer leads.

5. The stator according to claim 1, wherein the second support member comprises at least one arcuate portion axially positioned outward from the end coil and at least one axial branch extending between the arcuate portion and the shoulder of the cylindrical core.

6. A stator for an electric motor, the stator comprising: A core with multiple slots; A winding positioned on the core, the winding including an in-slot portion, end turns and leads, the leads of the winding including a plurality of inner leads associated with a conductor in the inner layer of the slot and a plurality of outer leads associated with a conductor in the outer layer of the slot; as well as A busbar assembly includes a plurality of inner busbars and a plurality of outer busbars held by a support member. The plurality of inner busbars are connected to a plurality of inner leads, and the plurality of outer busbars are connected to a plurality of outer leads. The plurality of inner busbars are axially positioned outward from the end of the end coil, and the plurality of outer busbars are radially positioned outward from the end coil and axially positioned inward from the end of the end coil. The support member includes a first support member made of a non-conductive material and a second support member made of a non-conductive material, wherein the first support member is different from the second support member, wherein at least some of the plurality of inner busbars are held by the first support member, and wherein the plurality of outer busbars are held by the second support member.

7. The stator of claim 6, wherein the slot portion is positioned in a slot of the core, the end turns of the winding extend from the slot portion at opposite ends of the core, and the lead of the winding extends from the slot portion at one end of the core, wherein the lead extends beyond the end turns in the axial direction.

8. The stator of claim 7, wherein the inner layer of the slot is the innermost layer, and the outer layer of the slot is the outermost layer.

9. The stator according to claim 8, wherein the plurality of inner busbars are further positioned radially inward from the plurality of outer busbars.

10. The stator according to claim 9, wherein the plurality of inner busbars and the plurality of outer busbars are further positioned radially inward from the outer diameter of the core and radially outward from the inner diameter of the core.

11. The stator of claim 6, wherein the first support member includes a first arcuate portion, wherein the second support member includes a second arcuate portion, wherein one side of the second arcuate portion faces the first arcuate portion, and wherein the other side of the second arcuate portion engages with the end of the end coil.

12. The stator of claim 11, wherein the first support member includes a plurality of terminal bridges extending axially outward from the first arcuate portion, and wherein the second support member includes a plurality of axial branches extending away from the second arcuate portion and engaging with the core.

13. The stator of claim 12, wherein the plurality of inner busbars include phase busbars, each phase busbar including a terminal plate engaging with one of the terminal bridges.

14. The stator of claim 6, wherein each of the external flow bars is provided by a U-shaped conductor segment having a first end extending in an axial direction, a first radially outward bend connected to the first end, a second end extending in the axial direction, a second radially outward bend connected to the second end, and an elongated circumferential portion extending in a circumferential direction between the first bend and the second bend.

15. The stator of claim 14, wherein the elongated circumferential portions of the external flow bar are separate and positioned in different planes, and wherein each of the elongated circumferential portions extends through an axial branch of the support.

16. The stator of claim 13, wherein each of the external flow bars is provided by a V-shaped conductor segment having a first end extending in an axial direction, a first radially outward bend connected to the first end, a second end extending in the axial direction, a second radially outward bend connected to the second end, and a V-shaped portion extending between the first bend and the second bend along a route including a circumferential component, an axial component, and a radial component.

17. The stator of claim 11, wherein the plurality of inner busbars includes a neutral bar positioned between the first support member and the second support member.

18. The stator of claim 6, wherein the plurality of busbars provides at least one series connection between two winding paths terminating at the outer lead, and wherein each of the plurality of busbars (i) has the same cross-sectional shape as the lead of the winding, (ii) is coated with an insulating material, and (iii) includes a trimmed end that exposes the conductive material of the busbar at the trimmed end.

19. A busbar assembly comprising: Multiple inner busbars, each including a neutral connecting bar and multiple phase connecting bars, each inner busbar including a circumferential portion and multiple axial connecting arms; A first support member, which engages with each of the inner busbars, the first support member including a first non-conductive arcuate portion; Multiple foreign exchange flow bars are radially outwardly positioned from the multiple inner flow bars, each of the foreign exchange flow bars including a circumferential portion extending between two axial connecting arms; as well as A second support member, which engages with each of the said foreign exchange flow strips, the second support member including a second non-conductive arcuate portion, at least one axial branch extending from the second non-conductive arcuate portion, and wherein the neutral connecting strip is positioned between the first support member and the second support member.

20. The busbar assembly according to claim 19, wherein, At least some of the plurality of internal confluence bars extend through the first support, and at least some of the plurality of external confluence bars extend through the second support.

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