Motor winding, motor and manufacturing method thereof

Abstract

The invention discloses a compact winding for a multi-phase electric machine. For each phase, there is provided a wire having an overhang with a special shape. In addition to one, all of the various pendants have a U-shaped bend to receive at least one cross-over of the other wire. The widths of the U-shaped bends vary depending on the phase, so that the wires can be inserted into the stator slots in a staggered manner. A stepped deformation having the same shape in all phases is used to connect different layers of the winding. Electrical contacts of the winding are provided at the overhang without affecting the staggered arrangement across the wire portions.

Description

Technical Field

[0001] The present invention relates to an electric machine, and in particular to a winding with a compact geometry for an electric machine, an electric machine with such a winding, and a method for manufacturing such a winding. Background Art

[0002] In traditional electric motors, windings are the main functional motor components. Current passes through the winding wires arranged in a magnetic field to generate torque to rotate the machine. In this way, the motor converts electrical energy (current) into mechanical energy (motion). In order to advance electric vehicles and other means of transportation, high-power, high-torque motors are required, which have the characteristics of low mass, small size, and high energy efficiency. In order to achieve these design goals, windings for electric motors with compact structures are sought.

[0003] Electric machines with various winding geometries are known in the art. For example, patent documents WO 03 / 094328 A1 and WO 05 / 117243 A1, for example, disclose windings with a large number of discrete coils. However, the production and assembly of a large number of coils is both expensive and time-consuming. In addition, windings with discrete coils have poor mechanical properties and require a large number of electrical contacts.

[0004] As an alternative, block coils are known in the art, in which all coils of the same phase are made into a single continuous piece, which is inserted into the slots of the ferromagnetic core. For example, patent document WO 2005 / 050816 A2 discloses a locking winding formed by lap windings, in which each conductor of the lap winding rotates around a single pole several times before going to the next pole. The problem with lap windings is also that when each stator tooth or group of teeth has a large number of turns, there is a lack of space for the winding ends of adjacent coils to cross. Another problem is the non-destructive insertion of the conductors into the slots.

[0005] These problems can be avoided to some extent by a locked winding structure known as wave winding. In wave winding geometry, the wire is made into a curved shape and wound between the poles so that the same wire returns to the same slot only in the next stage of winding.

[0006] Patent document WO 2006 / 110498 A1 discloses a wave winding geometry with a small number of electrical conductors per slot, wherein the conductors can be cut from a copper sheet, which can provide any contour shape. Patent document US 8 082 653 B2 also discloses a method of forming a rectangular winding by twisting the ends into a bundle of wires and folding the bundle of wires into a coil to form the coil without causing any undesirable deformation of the phase winding.

[0007] However, even wave windings with a small number of conductors encounter the problem of adjacent winding ends crossing the axial sides of the stator and being outside the ferromagnetic core. In this area, the electrical conductors are not straight and parallel, but curved. This problem is particularly evident in multi-phase machines where the conductors of multiple phases cross each other due to the limited space at all winding ends, especially when the number of winding layers is two or more. In addition, from a topological point of view, the problem of the order in which the conductors of each phase are inserted into the ferromagnetic core in a way that effectively avoids the intersection of the winding ends has not been solved.

[0008] In a wave winding with a small number of electrical conductors per slot, these conductors are relatively thick and strong. As a result, the winding ends cannot be easily bent into the correct shape, which is necessary for a tight fit of all winding ends. During the insertion of the coil into the ferromagnetic core, the winding ends can only be forced into the correct shape under great pressure, which can cause a risk of winding damage.

[0009] Patent document JP 2004 / 282 996 A discloses a stator winding with cascaded closed loops. By using rectangular wires, a stator with a high slot fill factor can be achieved. The multiple wires in each slot are arranged radially and precisely matched to the width of the rectangular core slot. Stators with a high slot fill factor are advantageous because they are efficient and produce more power per winding than other prior art stators. However, a disadvantage of these stators in general is that the windings are staggered (i.e., the wires need to cross radially outside and inside each slot). These staggered windings require a staggered preparation process to bundle the phase wires together before inserting the winding into the stator core. This increases complexity.

[0010] Other prior art stators also use flat wires. For example, in the stator disclosed in US 10965 178 B2, hairpin-shaped wires are arranged in the core slots at the upper or lower end of the stator core in the axial direction. Although the flat wires are not staggered, the difficulty of manufacturing the stator is still increased because the two ends of the hairpin-shaped wires must be welded to form the stator winding.

[0011] Therefore, a stator is needed that can achieve a high slot fill rate without requiring a complicated interleaved winding process or a large number of welding points of flat wire conductors. Summary of the invention

[0012] All known solutions have issues with cost, weight, maximum torque, energy efficiency and manufacturing complexity.

[0013] It is therefore an object of the present invention to overcome these problems and to provide an electric machine winding with a compact geometry enabling a high power and high torque electric machine with low mass, low volume and high energy efficiency. A further object of the present invention is to provide a method for manufacturing such a winding in an economical manner, in particular by inserting the individual wires one by one in several layers while requiring as few solder contacts as possible.

[0014] This is achieved by means of the features described in the independent claim. Preferred embodiments are the subject matter of the dependent claims.

[0015] The winding geometry disclosed herein provides an optimal fit between adjacent winding overhangs, thereby making the winding highly dense, compact and easy to manufacture. The motor using such winding can achieve high specific torque and power, has very excellent energy efficiency, is characterized by high heat transfer coefficient and high thermal conductivity from the winding to the stator core, and has the advantages of improved machine cooling and easy motor assembly process.

[0016] The present invention can be used for the power of electric vehicles and other vehicles, especially vehicles with direct wheel hub drive, for the power of general rotating electrical machines, and in various other fields using motor / generators.

[0017] A particular aspect of the invention is to provide the overhang of each phase with a specific geometry, ie an overhang with a U-shaped bend whose width varies from phase to phase and is adapted to fit the traverses of at least some other phases.

[0018] According to a first aspect of the present invention, a winding for a motor is provided. The winding comprises a first conductor (100), a second conductor (200) and a third conductor (300). Each of the first conductor (100), the second conductor (200) and the third conductor (300) comprises two parallel conductor portions (110, 120, 210, 220, 310, 320) connected to each other via a hanging portion (130, 230, 330). A first parallel conductor portion (110) of the first conductor (100) is arranged to be embedded in a first slot of a plurality of slots of a rotor or a stator of the motor. A first parallel conductor portion (210) of the second conductor (200) is arranged to be embedded in a second slot of the plurality of slots, the second slot being adjacent to the first slot. A first parallel conductor portion (310) of the third conductor (300) is arranged to be embedded in a third slot of the plurality of slots, the third slot being adjacent to the second slot and different from the first slot. The second parallel conductor portion (120) of the first conductor (100) is arranged to be embedded in a fourth slot among the plurality of slots, the fourth slot being different from the first slot, the second slot and the third slot. The second parallel conductor portion (220) of the second conductor (200) is arranged to be embedded in a fifth slot among the plurality of slots, the fifth slot being adjacent to the fourth slot and being different from the third slot. The second parallel conductor portion (320) of the third conductor (300) is arranged to be embedded in a sixth slot among the plurality of slots, the sixth slot being adjacent to the fifth slot and being different from the fourth slot. The winding is characterized in that the overhang portion (130) of the first conductor (100) includes a first U-shaped bend portion (190) arranged in a direction perpendicular to a plane defined by the two parallel conductor portions (110, 120), the first U-shaped bend portion (190) being formed to accommodate a traversing portion of the overhang portion (230) of the second conductor (200) and a traversing portion of the overhang portion (330) of the third conductor (300). The overhang (230) of the second conductor (200) includes a second U-shaped bend (290) arranged in a direction perpendicular to the plane defined by the two parallel conductor portions (210, 220), and the second U-shaped bend (290) is formed to accommodate the crossing portion of the overhang (330) of the third conductor (300). The overhang (330) of the third conductor (300) is contained in the plane defined by the two parallel conductor portions (310, 320).

[0019] The first conductive wire (100), the second conductive wire (200), and the third conductive wire (300) may correspond to a first phase of the winding, a second phase of the winding, and a third phase of the winding, respectively.

[0020] In a preferred embodiment, the winding has three phases. In this case, the fourth slot is adjacent to the third slot. In another optional embodiment, the winding has N phases, where N is an integer greater than 3, and the fourth slot is separated from the third slot by N-3 slots.

[0021] In addition, the width of the first U-shaped bend (190) may be equivalent to the pitch of the plurality of grooves plus the width of one of the plurality of grooves, and the width of the second U-shaped bend (290) may be equivalent to the width of one of the plurality of grooves.

[0022] Furthermore, each of the depth of the first U-shaped bend (190) and the depth of the second U-shaped bend (290) may be equivalent to the width of the third conductive line (300) in a direction perpendicular to a plane defined by the two parallel conductive line portions.

[0023] According to another preferred embodiment, each overhanging portion (130, 230, 330) of the first, second and third conductors (100, 200, 300) comprises an extension portion (140, 240, 340) connected to and possibly co-linear with the first parallel conductor portion (110, 210, 310), a first bend portion (150, 250, 350) connected to the extension portion (140, 240, 340), an oblique portion (160, 260, 360) connected to the first bend portion (150, 250, 350), and a second bend portion (170, 270, 370) connecting the oblique portion (160, 260, 360) and the second parallel conductor portion (120, 220, 320). Furthermore, the first U-shaped bend (190) is arranged in the miter portion (160) of the overhang portion (130) of the first wire (100), and the second U-shaped bend (290) is arranged in the oblique portion (260) of the overhang portion (230) of the second wire (200).

[0024] The overhang portion thus forms a right triangle, wherein the hypotenuse is formed by the oblique line portion (160, 260, 360). The first curved portion thus forms an acute angle (150, 250, 350), and the second curved portion (170, 270, 370) thus forms an obtuse angle.

[0025] With such an arrangement, the extension portion (140, 240, 340) of each overhang of the first, second and third wires (100, 200, 300) can have a length that allows the overhang (330) of the third wire (300) to cross the first U-shaped bend (190) in the overhang (130) of the first wire (100) and the second U-shaped bend (290) in the overhang (230) of the second wire (200).

[0026] In addition, the first U-shaped bend (190) can be formed so that its own groove accommodates the extension portion (240) of the second wire (200) and the extension portion (340) of the third wire (300), the second U-shaped bend (290) can be formed so that its own groove accommodates the extension portion (340) of the third wire (300), and the groove in the first U-shaped bend (190) can be wider than the groove in the second U-shaped bend (290).

[0027] Preferably, each of the first, second and third conducting wires (100, 200, 300) further comprises a plurality of parallel conducting wire portions (110, 120, 210, 220, 310, 320) connected in series by a plurality of overhanging portions (130, 230, 330).

[0028] According to another preferred embodiment, the winding further comprises a fourth conductor (400), a fifth conductor (500) and a sixth conductor (600), each of which comprises two parallel conductor portions connected by an overhanging portion. The first parallel conductor portion of the fourth conductor (400) is arranged to be embedded in the fourth slot and located on top of the second parallel conductor portion of the first conductor (100). The first parallel conductor portion of the fifth conductor (500) is arranged to be embedded in the fifth slot and located on top of the second parallel conductor portion of the second conductor (200). The first parallel conductor portion of the third conductor (600) is arranged to be embedded in the sixth slot and located on top of the second parallel conductor portion of the third conductor. The second parallel conductor portion of the fourth conductor (400) is arranged to be embedded in a seventh slot of the plurality of slots, the seventh slot being adjacent to the sixth slot and being different from the fifth slot. The second parallel conductor portion of the fifth conductor (500) is arranged to be embedded in an eighth slot of the plurality of slots, the eighth slot being adjacent to the seventh slot and being different from the sixth slot. The second parallel wire portion of the sixth wire (600) is arranged to be embedded in a ninth slot of the plurality of slots, the ninth slot being adjacent to the eighth slot and different from the seventh slot. The overhang portion of the fourth wire (400) includes a third U-shaped bend arranged in a direction perpendicular to the plane defined by the two parallel wire portions, the third U-shaped bend being formed to accommodate a crossover portion of the overhang portion of the fifth wire (500) and a crossover portion of the overhang portion of the sixth wire (600). The overhang portion of the fifth wire (500) includes a fourth U-shaped bend arranged in a direction perpendicular to the plane defined by the two parallel wire portions, the fourth U-shaped bend being formed to accommodate a crossover portion of the overhang portion of the sixth wire (600). The overhang portion of the sixth wire (600) is contained within the plane defined by the two parallel wire portions.

[0029] In this way, windings having multiple layers can be produced.

[0030] According to another preferred embodiment, the winding further comprises a step-deformed conductor (700), comprising two parallel conductor portions (710, 720) connected by a hanging portion, wherein the first parallel conductor portion (710) of the step-deformed conductor (700) is arranged to be embedded in the tenth slot of the plurality of slots, and the second parallel conductor portion (720) of the step-deformed conductor (700) is arranged to be embedded in the thirteenth slot spaced two slots from the tenth slot. The first parallel conductor portion (710) of the step-deformed conductor (700) is arranged in a first layer of the winding, and the second parallel conductor portion (720) of the step-deformed conductor (700) is arranged in a second layer of the winding adjacent to the first layer. The hanging portion of the step-deformed conductor (700) comprises an extension portion (740) connected to the first parallel conductor portion (710) and possibly co-linear, a first curved portion (750) connected to the first straight portion (740), an oblique portion (760), a second curved portion (770) connecting the oblique portion (760) and the second parallel conductor portion (720), and an S-shaped portion (790) connecting the first curved portion (750) arranged in the first layer and the oblique portion (760) arranged in the second layer.

[0031] In this way, the wires in two adjacent layers can be electrically connected.

[0032] According to another preferred embodiment, the winding further comprises a first coil contact wire (800), a second coil contact wire (900), and a third coil contact wire (1000), each of the first coil contact wire (800), the second coil contact wire (900), and the third coil contact wire (1000) comprising a parallel wire portion (820, 920, 1020) connected to an overhang portion (830, 930, 1030), and the parallel wire portions (820, 920, 1020) are arranged in a third layer of the winding. Each overhang (830, 930, 1030) of the first, second and third coil contact wires (800, 900, 1000) comprises an extension (840, 940, 1040) arranged in a fourth layer of the winding adjacent to the third layer and extending from the winding, a first bend (850, 950, 1050) connected to the extension (840, 940, 1040), a slanted portion (860, 960, 1060) connected to the first bend (850, 950, 1050), and a second bend (870, 970, 1070) connecting the slanted portion (860, 960, 1060) and the parallel wire portion (820, 920, 1020). The parallel wire portion (820) of the first coil contact wire (800) is arranged to be embedded in the fourth slot, the parallel wire portion (920) of the second coil contact wire (900) is arranged to be embedded in the fifth slot, and the parallel wire portion (1020) of the third coil contact wire (1000) is arranged to be embedded in the sixth slot. The extension portion (840) of the first coil contact wire (800) contacts the fourth coil contact wire (1100), and the fourth coil contact wire (1100) is connected to a parallel wire portion arranged in the first slot and in the third layer of the winding and may be in line. The extension portion (940) of the second coil contact wire (900) contacts the fifth coil contact wire (1200), and the fifth coil contact wire (1200) is connected to a parallel wire portion arranged in the second slot and in the third layer of the winding and may be in line. The extension portion (1040) of the third coil contact wire (1000) contacts the sixth coil contact wire (1300), and the sixth coil contact wire (1300) is connected to a parallel wire portion arranged in the third slot and in the third layer of the winding and may be colinear. The oblique line portion (860, 960, 1060) in the first, second and third coil contact wires (800, 900, 1000) includes an S-shaped portion (890, 990, 1090) arranged between the third layer and the fourth layer, so that the fifth and sixth coil contact wires (1200, 1300) both cross the oblique line portion (860) of the first coil contact wire (800), and the sixth coil contact wire (1300) crosses the oblique line portion (960) of the second coil contact wire (900).

[0033] In this way, an electrical connection or tap can be made for each conductor of the winding.

[0034] Preferably, the ratio of the tooth width of the stator or rotor to the thickness of the wire is greater than 1.5. Moreover, the axial length of the overhanging portion may be equal to: o=(4*w+3*s) / 1.8 Where w is the wire width, and s is the stator or rotor tooth width.

[0035] According to a second aspect of the present invention, there is provided an electric motor, comprising a stator having the plurality of slots and the winding as described above.

[0036] According to a third aspect of the present invention, a method for manufacturing a motor winding is provided. The method comprises the following steps: forming a first wire (100), a second wire (200) and a third wire (300) wire rod, wherein each of the first wire (100), the second wire (200) and the third wire (300) comprises two parallel wire parts connected by a suspended part, and inserting the first wire (100), the second wire (200) and the third wire (300) into a plurality of slots of a motor rotor or a stator in a prescribed order. The above steps are performed so that the first parallel wire part of the first wire (100) is embedded in a first slot of a plurality of slots, the first parallel wire part of the second wire (200) is embedded in a second slot of a plurality of slots adjacent to the first slot, the first parallel wire part of the third wire (300) is embedded in a fifth slot of a plurality of slots adjacent to the fourth slot and different from the third slot, and the second parallel wire part of the third wire (300) is embedded in a sixth slot of a plurality of slots adjacent to the fifth slot and different from the fourth slot. In addition, the wire is formed so that the overhanging portion of the first wire (100) includes a first U-shaped bend (190) arranged in a direction perpendicular to the plane defined by the two parallel wire portions (110, 120), the first U-shaped bend (190) is manufactured to accommodate a cross portion of the overhanging portion (230) of the second wire (200) and a cross portion of the overhanging portion (330) of the third wire (300), and the overhanging portion of the second wire (200) includes a second U-shaped portion (290) arranged in a direction perpendicular to the plane defined by the two parallel wire portions (210, 220), the second U-shaped portion (290) is manufactured to accommodate a cross portion of the overhanging portion (330) of the third wire (300), and the overhanging portion (330) of the third wire (300) is confined within the plane defined by the two parallel wire portions (310, 320). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention is illustrated by way of example and not limitation in the accompanying drawings, in which like reference numerals indicate similar elements, and in which: Figure 1 is a schematic diagram showing a portion of a winding stator according to an embodiment of the present invention; Figure 2A is a schematic diagram showing a suspension portion of a first phase conductor in a three-phase motor according to an embodiment of the present invention; Figure 2B is a schematic diagram showing a suspension portion of a second phase conductor in a three-phase motor according to an embodiment of the present invention; Figure 2C is a schematic diagram showing a suspension portion of a second phase conductor in a three-phase motor according to an embodiment of the present invention; Figure 3A is a schematic diagram showing the geometric shape of the overhanging portion of the winding of a three-phase motor according to an embodiment of the present invention; Figure 3B is a schematic diagram showing the geometric shape of windings of a three-phase motor according to an embodiment of the present invention; Figure 4A is a schematic diagram showing a two-layer structure of a winding overhang portion for a three-phase motor according to an embodiment of the present invention; Figure 4B is a schematic diagram showing a three-layer structure of a winding overhang for a three-phase motor according to an embodiment of the present invention; Figure 4C is a schematic diagram showing a six-layer structure of a winding overhang for a three-phase motor according to an embodiment of the present invention; Figure 5A is a schematic diagram showing a stepped deformation structure of a single conductor for a three-phase motor according to an embodiment of the present invention; Figure 5B is a schematic diagram showing a stepped deformation structure of all three conductors for a three-phase motor according to an embodiment of the present invention; Figure 5C It is shown Figure 5B Another schematic diagram of the stepped deformation structure; Fig. 6A is a schematic diagram of a first-phase conductor contact portion of a three-phase motor according to an embodiment of the present invention; Figure 6B is a schematic diagram of a contact portion of a second phase conductor of a three-phase motor according to an embodiment of the present invention; Figure 6C is a schematic diagram of a contact portion of a third-phase conductor of a three-phase motor according to an embodiment of the present invention; Fig. 7A is a schematic diagram of contact parts of all wires in one layer of a three-phase motor according to an embodiment of the present invention; Figure 7B is a schematic diagram of contact parts of all wires in two layers of a three-phase motor according to an embodiment of the present invention; Figure 7C yes Figure 7B Another schematic diagram of the contact portion; Figure 8 is a schematic diagram of alternative configurations of overhangs according to various embodiments of the present invention; Fig. 9 FIG. 4 is a schematic diagram showing the structure of the overhanging portion of a six-phase motor according to another embodiment of the present invention. DETAILED DESCRIPTION

[0038] The invention is disclosed in connection with an inner stator type of synchronous motor with permanent magnets, but is not limited to this particular type of motor and can also be used for other types, such as an outer stator or any other induction motor or other type of motor. The invention can also be used for linear actuators of linear motors, where the active part of the motor extends to the straight part of the end length. Furthermore, the topological and structural solutions of the windings described can be implemented in the stator or rotor of the engine. For simplicity, the invention is to provide a stator winding, in particular an inner stator three-phase permanent magnet synchronous motor type used in the applicant's wheel hub motor.

[0039] The winding for an electric machine according to the invention may comprise a plurality of turns for a plurality of phases. In the following, the geometry of the winding is mainly explained in the context of a three-phase electric machine. However, the invention is not limited to three-phase electric machines and may also be applied to electric machines having four, five, six or any other integer number of phases.

[0040] Figure 1 is a schematic diagram of a portion of a stator with windings according to an embodiment of the present invention. Each turn of the winding coil consists of a straight portion of a wire located in a stator slot and a curved overhang that brings the wire from one side of the coil to the other. Since the same-phase windings are electrically connected in series, they belong to the same wire portion from one coil to the next. The overhangs intersect when they are in a plane, that is, when the wires cross each other, they physically interfere with each other. In order to solve the problem of manufacturing such a structure, the present invention provides a well-defined path for the wire so that the winding can be packaged in the desired form. In addition, when the next layer is added for the next winding turn, the in-slot portion of the wire must be matched and installed on top of the previous layer without any vertical space in between. Therefore, the present invention provides a winding geometry with a triangular overhang that allows the straight wire of each turn to be arranged in a plane of one layer, while the wires of consecutive turns can be simply stacked on top of each other without any space between this layer and the next layer.

[0041] According to a specific embodiment of the present invention, N types of conductors are used to manufacture the windings of an N-phase motor. The difference between the N types of conductors lies in the shape of their overhangs. At this time, the overhang of each conductor basically includes a 180° U-turn, which is used to return the current from the straight conductor portion in one stator slot to the straight conductor portion in the opposite direction in the next stator slot, and all of these overhangs except one of them also include a radial U-shaped bend, which is formed to facilitate the cross arrangement with one or more conductors of other phases. The width of these U-shaped bends is suitable for the conductors of each phase, so that the U-shaped bend of the i-th phase conductor can accommodate the (i+1), (i+2), ..., n-th phases. On the other hand, the overhang of the n-th phase is basically confined to the radial layer corresponding to the turn, and there is no U-shaped bend in the radial direction.

[0042] Figure 2-Figure 6 gives the general idea of ​​the three-phase motor example.

[0043] According to an embodiment of the present invention, FIG. 2A to FIG. 2C The overhangs of the conductors for the first phase, the second phase and the third phase of the three-phase motor are shown respectively. Figure 3A It shows how the three different wire shapes are arranged crosswise with each other when inserted into their respective stator slots. Figure 3B It is a top view of the straight wires on both sides of the stator connected by the overhangs. The overhangs on both sides are mirror-symmetrical along the length of the wave winding.

[0044] It can be seen that the two straight conductor portions (110, 120) of the conductor (100) for the first phase are connected by an overhang (130) having a U-shaped bend (190) which is wide enough to accommodate the crossover portions of the conductors (200, 300) for the second and third phases. The conductor (200) for the second phase has a similar structure except that the U-shaped bend (290) is narrower because it only needs to accommodate the crossover portion of the conductor for the third phase. On the other hand, the conductor (300) for the third phase is flat without a U-shaped bend in the radial direction.

[0045] In a three-phase system, a wide U-bend (190) is placed at the long arm (160) of the triangular overhang (130). It is a step deformation that forms a slot with a depth comparable to the thickness of the conductor. There are two such steps, left and right. The step deformation is preferably extended across the entire width of the stator tooth to provide the least intrusive deformation with respect to isolation stresses. The slot width of the double U-bend (the flat space (190) between the left and right steps) must accommodate the straight portions of the other two overhangs extending from the next two stator slots. Under the first phase conductor (100), the slot (190) needs to cover the entire stator pitch plus one slot width.

[0046] The narrow U-bend (290) is similar to the wide U-bend (190). It is also located at the long arm (260) of the overhang. The left and right steps are the same as above, extending across the entire stator tooth width. The difference is the width of the slot (290).

[0047] The flat overhang (330) has no U-shaped bend and simply delivers the wire to the next coil side of the same layer.

[0048] The wires are inserted into the stator slots in layers. Each layer corresponds to one turn of the winding. Therefore, the number of layers is equal to the number of turns. A complete turn of the winding consists of two parallel wire sections inside the stator slot and a corresponding overhang outside the stator slot. The height of the layer is twice the height of the wire, viewed radially. The height of the overhang is equal to (M+1) times the height of the wire, where M is the number of layers. The winding remains compact when cascaded to any number of turns (layers).

[0049] In this embodiment, the overhang extends to three times the wire width, which is the smallest overhang in terms of geometric dimensions. The wider the stator pitch, the wider the vertex angle of the overhang. If the stator pitch is narrower, the vertex angle of the overhang will become more acute. In this way, the winding can be easily scaled to different stator slot / pitch geometries.

[0050] The wires are placed in the stator core slots in the following order: the first wire with a wide U-bend overhang is placed first. The second wire with a narrow U-bend overhang is placed in the slot adjacent to the right of the first wire, and the third wire with a flat overhang is placed in the next slot adjacent to the right of the second wire. Obviously, the winding can be wound in any direction, clockwise or counterclockwise. The shape of the wire and the assembly order ensure that there is no interference between the wires, such as Figure 3A shown.

[0051] Figure 4A It shows how the three-phase conductors (400, 500, 600) of the second layer are stacked onto the three-phase conductors (100, 200, 300) of the first layer. Figure 4B shows the overhang of the three-layer three-phase motor winding, and Figure 4C An example of six layers is shown.

[0052] It can be seen that the next layer of wires is shifted three slots relative to the first layer, and the wires are placed in the slots in the same order as the first layer. The third layer is placed on top of the second layer, with the winding overhang aligned with the first layer. Each layer alternates the shifting of the wires in this order.

[0053] It goes without saying that the invention is not limited to windings with only two, three or six layers. Figure 4A-4CAs shown. Alternatively, any number of layers may be used as desired. Moreover, the terms "first layer", "second layer", etc. do not imply that the corresponding layer is the first layer (i.e., the innermost layer) or the second layer (i.e., the layer above the "first layer") in the winding. Instead, the terms are used as placeholders for any layer in a multi-layer winding, unless otherwise explicitly stated. The same applies to the terms "first slot", "second slot", etc., which should be understood as placeholders for any slot of a multi-slot stator. Unless otherwise specified, the "second slot" and "third slot" are not necessarily the slots that immediately follow the "first slot" according to a certain scheme for consecutively numbering the stator slots. Therefore, the slots of the "first slot", "second slot", etc. are not limited to the slots marked as "slot 1", "slot 2", etc. in the figure.

[0054] In order to be able to assemble arbitrary windings with respect to combinations of wires connected in series or in parallel, two additional features are provided: transitioning winding segments of one continuous wire from one layer to the next and providing wire extensions for the contacts while the wire is cut, enabling wiring to continue on the same or next layer.

[0055] The step deformation required to connect two adjacent layers of wires is as follows: Figure 5A-5C As shown. The step variant has the same shape in all three phases. The overhang transitions from one layer to the next in one step. This type of variant can be used for all variants, including flat wire windings.

[0056] In order to provide electrical contact points for the windings, the wires need to extend from the windings to allow space for welding. According to the invention, this is achieved by providing contact portions for the conductors of each phase.

[0057] FIG. 6A to FIG. 6C The contact parts of the three-phase conductors of the three-phase motor are shown separately. The relationship between the three contact parts in one layer of the three-phase motor is as follows Fig. 7A shown. Figure 7B Shows the contact parts of all wires in two layers of a three-phase motor. Figure 7C yes Figure 7B Side view of the structure shown in .

[0058] With this geometry it is a very simple solution as the wires are not staggered.

[0059] Geometrically, the wires are cut at the apex of the overhang, with a point where the wires extend out of the stator coil to provide space for welding or other electrical contact. For the overhangs with wide U-bends (190) and narrow U-bends (290), the step near the apex (150, 250) is omitted and the wires (840, 940, 1040) extend out of the winding, while the flat overhang is provided with a descending step at the apex. In this way, all three wires are led out of the lower layer of the winding. Fig. 7AAs shown, the windings are kept in the same layer by simply extending the straight portions (1010, 1020, 1030) of the continuous wire in the slots.

[0060] By properly arranging the wire cutting and the cross-layer design (i.e. parallel wires), the stator can be assembled with any desired combination of coil turns or wire cross-sections. The contacts can be appropriately distributed along the stator circumference to make it easier to access the wire ends for electrical connection.

[0061] Figure 1 - The overhang structure shown in FIG7 is based on an oblique triangle. However, the present invention can also be implemented with triangles of different shapes, including left-oblique triangles, symmetrical triangles and right-oblique triangles, such as Figure 8 shown.

[0062] The shape of the overhang, especially the U-bend, can be limited only by the wire width, wire height and stator tooth size. The reason is that very thick wires require more bending space. As a rule of thumb, the ratio of stator tooth width to wire thickness should be at least 1.5.

[0063] The characteristic parameters of the winding geometry are Figure 8 The angle α shown is the angle at which the wire leaves the stator slot and enters the overhang. There is a minimum angle when the wires are closely packed. The angle α when the wires are packed together is greater than or equal to: α ≥ arcsin(( w + δ ) / ( s + w )) Where w is the width of the wire, here considered to be equal to the stator slot, s is the width of the stator tooth, and therefore (s + w) is the pitch of the stator. For different embodiments, this angle can be varied from this minimum angle to 90 degrees. The parameter δ is a width correction value used to provide some margin between the wires, which is required because the U-shaped bend cannot be bent with a radius of zero. When the vertex of the overhang moves from left to right, different embodiments are obtained. In the present disclosure, the exemplary embodiment is a right-angled triangle.

[0064] The wire on the left extends straight out of the slot, forming a right triangle. By forming a smaller departure angle, the vertex of the overhang moves toward the midpoint, where both angles are equal to α, and the overhang almost forms an isosceles triangle. By moving the vertex to the right, the departure angle of the wire on the right will eventually reach 90 degrees, forming the right overhang. The angle α where the wires are closely packed now moves to the other side. The optimal geometry of the overhang is close to the middle, where the overhang forms an isosceles triangle.

[0065] The U-bend needs to accommodate the cross arrangement of the remaining wires. This winding geometry can be used for any number of phases. In the exemplary embodiment (left and right triangle) of wire i = 1, ..., (N-1) for any phase, the corresponding U-bend should extend along the line by a distance d: d * cos(α) = (N - i - 1) * (s + w) + w; i ∊ {1, ..., N-1} d = 0; i = N, Where N is the number of phases and i is the wire of the i-th phase. The wire of the last phase is flat (i=N). Here, considering that the wire cannot be bent with a zero radius, this distance along the wire will be slightly longer and can be obtained from the 3D model of the winding.

[0066] For a three-phase system, three types of deformation are required to form the overhang of each turn of the winding: a wide U-shaped bend, a narrow U-shaped bend, and a flat overhang, such as Figure 2A-2C The next layer is displaced circumferentially (in the plane of the layer) so that the overhang of the next layer is inserted and the parallel slots of the wire fit inside the top of the previous layer without losing any space between layers and without causing the winding to waste space in the overhang.

[0067] The disclosed geometry can also be applied to so-called double-coil transtorque windings, where the number of wires would be 2*N.

[0068] The space required in the U-bend to accommodate the crossovers of the other winding wires may create geometrical limitations. As long as the long arm length of the triangle can accommodate a wide U-bend with a double wire crossing, three sequential wire loops for three phases can be provided.

[0069] Furthermore, the present invention is not limited to windings for three-phase motors, but may be used with any number of phases, including 4, 5, 6 or even more phases.

[0070] Fig. 9 The structure of the overhang portion for a six-phase motor according to another embodiment of the present invention is shown. It can be seen that a conductor of different shapes is provided for each phase, wherein all conductors except one conductor have a U-shaped bend portion for accommodating the crossover portion of at least one of the other conductors. In this example, the conductor (100) for the first phase has a wide U-shaped bend portion for accommodating the crossover portion of each of the other conductors. Since the conductor (200) of the second phase only needs to accommodate the 3rd to 6th conductors, its U-shaped bend portion is not as wide as the first conductor (100). Finally, the conductor (300) of the last phase is substantially flat.

[0071] Thus, the present invention provides a winding for an electric machine which is compact and has low resistance and leakage inductance due to short wiring. In addition, a large number of turns can be achieved by simply stacking multiple preformed wires on top of each other while maintaining a high slot fill factor.

[0072] Furthermore, the wiring pattern according to the invention makes it easy to manufacture, since each linear segment of each layer is located at the same radial distance from the central axis of the stator core, so that the stator windings are not staggered, since they are not staggered with other wires in the slots between front and rear positions. Each closed loop segment advantageously forms a cascade winding pattern. Therefore, the complex staggered winding process of the prior art is not required. Instead, the formed wires can simply be embedded into the stator slots one by one. This allows a particularly simple machine to be used for fast and safe wire embedding, thereby enabling large-scale production. At the same time, a high degree of flexibility is maintained, and different types of motors with different numbers of wire layers and winding topologies can be produced. The use of only a limited number of wires of different shapes also provides advantages for the construction of wire forming tools, so that a variety of wire overhangs can be formed simultaneously.

[0073] In summary, the present invention provides a compact winding for a multi-phase electric machine. For each phase, a conductor is provided with an overhang of a particular shape. All but one of the various overhangs have a U-shaped bend to accommodate the crossover of at least one other conductor. The width of the U-shaped bends varies from phase to phase so that the conductors can be inserted into the stator slots in a staggered manner. A step deformation having the same shape in all phases is used to connect the different layers of the winding. Electrical contacts for the winding are provided at the overhangs without violating the staggered arrangement of the crossover conductor portions.

Claims

1. A motor winding, comprising: A first conductive wire (100), a second conductive wire (200), and a third conductive wire (300), each of the first conductive wire (100), the second conductive wire (200), and the third conductive wire (300) comprising two parallel conductive wire portions (110, 120, 210, 220, 310, 320) connected by a hanging portion (130, 230, 330); Wherein, the first parallel conductor portion (110) of the first conductor (100) is arranged to be embedded in a first slot among a plurality of slots of a rotor or a stator of the motor; Wherein, the first parallel conductor portion (210) of the second conductor (200) is arranged to be embedded in a second groove among the plurality of grooves adjacent to the first groove; Wherein, the first parallel conductor portion (310) of the third conductor (300) is arranged to be embedded in a third groove among the plurality of grooves which is adjacent to the second groove and different from the first groove; The second parallel conductor portion (120) of the first conductor (100) is arranged to be embedded in a fourth slot among the plurality of slots that are different from the first slot, the second slot and the third slot; The second parallel conductor portion (220) of the second conductor (200) is arranged to be embedded in a fifth groove among the plurality of grooves which is adjacent to the fourth groove and different from the third groove; The second parallel conductor portion (320) of the third conductor (300) is arranged to be embedded in a sixth slot among the plurality of slots that is adjacent to the fifth slot and different from the fourth slot; Its characteristics are: The overhang portion (130) of the first conductor (100) comprises a first U-shaped bend portion (190) arranged in a direction perpendicular to a plane defined by the two parallel conductor portions (110, 120), the first U-shaped bend portion (190) being formed to accommodate a crossover portion of the overhang portion (230) of the second conductor (200) and a crossover portion of the overhang portion (330) of the third conductor (300); The overhang portion (230) of the second conductor (200) comprises a second U-shaped bend (290) arranged in a direction perpendicular to a plane defined by the two parallel conductor portions (210, 220), the second U-shaped bend (290) being formed to accommodate a crossing portion of the overhang portion (330) of the third conductor (300); and The overhanging portion (330) of the third conductive line (300) is contained within the plane defined by the two parallel conductive line portions (310, 320).

2. A motor winding according to claim 1, wherein the first wire (100), the second wire (200) and the third wire (300) correspond to the first phase of the winding, the second phase of the winding and the third phase of the winding respectively. 3 . The motor winding according to claim 2 , wherein the winding has three phases in total, and the fourth slot is adjacent to the third slot.

4. A motor winding according to claim 2, wherein the winding has N phases in total, N is an integer greater than 3, and the fourth slot is spaced N-3 slots away from the third slot.

5. A motor winding according to any of the preceding claims, wherein the width (190) of the first U-shaped bend corresponds to the pitch of the plurality of slots plus the width of one of the plurality of slots, and wherein the width (290) of the second U-shaped bend corresponds to the width of one of the plurality of slots.

6. A motor winding according to any of the preceding claims, wherein each of the depth of the first U-shaped bend (190) and the depth of the second U-shaped bend (290) is equivalent to the width of the third conductor (300) in a direction perpendicular to a plane defined by the two parallel conductor portions.

7. A motor winding according to any preceding claim; wherein each of the hanging portions (130, 230, 330) of the first, second and third conductors (100, 200, 300) comprises an extension portion (140, 240, 340) connected to the first parallel conductor portion (110, 210, 310), a first bend portion (150, 250, 350) connected to the extension portion (140, 240, 340), an oblique portion (160, 260, 360) connected to the first bend portion (150, 250, 350), and a second bend portion (170, 270, 370) connecting the oblique portion (160, 260, 360) and the second parallel conductor portion (120, 220, 320); in, The first U-shaped bend (190) is arranged in the oblique line portion (160) of the overhang portion (130) of the first wire (100), and the second U-shaped bend (290) is arranged in the oblique line portion (260) of the overhang portion (230) of the second wire (200).

8. A motor winding according to claim 7, wherein the extension portion (140, 240, 340) of each of the overhanging portions of the first, second and third conductors (100, 200, 300) has a length that allows the overhanging portion (330) of the third conductor (300) to cross over the first U-shaped bend (190) of the overhanging portion (130) of the first conductor (100) and the second U-shaped bend (290) of the overhanging portion (230) of the second conductor (200).

9. A motor winding according to claim 7 or 8, in, The first U-shaped bent portion (190) is formed so that a groove thereof accommodates the extension portion (240) of the second conductive wire (200) and the extension portion (340) of the third conductive wire (300); wherein the second U-shaped bent portion (290) is formed so that its groove accommodates the extending portion (340) of the third conductive wire (300); and The groove in the first U-shaped curved portion (190) is wider than the groove in the second U-shaped curved portion (290).

10. A motor winding according to any preceding claim, wherein each of said first, second and third conductors (100, 200, 300) further comprises a plurality of parallel conductor portions (110, 120, 210, 220, 310, 320) connected in series by a plurality of overhangs (130, 230, 330).

11. A motor winding according to any preceding claim, further comprising: A fourth wire (400), a fifth wire (500) and a sixth wire (600), each of the fourth wire (400), the fifth wire (500) and the sixth wire (600) comprising two parallel wire portions connected by a hanging portion; Wherein, the first parallel conductor portion of the fourth conductor (400) is arranged to be embedded in the fourth groove and located above the second parallel conductor portion of the first conductor (100); Wherein, the first parallel conductor portion of the fifth conductor (500) is arranged to be embedded in the fifth groove and located above the second parallel conductor portion of the second conductor (200); Wherein, the first parallel conductor portion of the third conductor (600) is arranged to be embedded in the sixth groove and located above the second parallel conductor portion of the third conductor (300); Wherein, the second parallel conductor portion of the fourth conductor (400) is arranged to be embedded in a seventh slot among the plurality of slots which is adjacent to the sixth slot and different from the fifth slot; The second parallel conductor portion of the fifth conductor (500) is arranged to be embedded in an eighth slot among the plurality of slots which is adjacent to the seventh slot and different from the sixth slot; The second parallel conductor portion of the sixth conductor (600) is arranged to be embedded in a ninth slot among the plurality of slots which is adjacent to the eighth slot and different from the seventh slot; wherein the hanging portion of the fourth wire (400) comprises a third U-shaped bend arranged in a direction perpendicular to a plane defined by the two parallel wire portions, the third U-shaped bend being formed to accommodate a crossing portion of the hanging portion of the fifth wire (500) and a crossing portion of the hanging portion of the sixth wire (600); wherein the overhanging portion of the fifth wire (500) comprises a fourth U-shaped bend arranged in a direction perpendicular to a plane defined by two parallel wire portions, and the fourth U-shaped bend is formed to accommodate a crossing portion of the overhanging portion of the sixth wire (600); Wherein, the overhanging portion of the sixth conductor (600) is contained in a plane defined by two parallel conductor portions.

12. A motor winding according to any preceding claim, further comprising: A step-deformed conductor (700), comprising two parallel conductor parts (710, 720) connected by a hanging part; The first parallel conductor portion (710) of the step-deformed conductor (700) is arranged to be embedded in the tenth slot of the plurality of slots, and the second parallel conductor portion (720) of the step-deformed conductor (700) is arranged to be embedded in the thirteenth slot which is two slots away from the tenth slot. Wherein, the first parallel conductor portion (710) of the step-deformed conductor (700) is arranged in a first layer of the winding, and the second parallel conductor portion (720) of the step-deformed conductor (700) is arranged in a second layer of the winding adjacent to the first layer; The hanging portion of the step-deformed conductor (700) comprises an extension portion (740) connected to the first parallel conductor portion (710), a first curved portion (750) connected to the first straight portion (740), an oblique portion (760), a second curved portion (770) connecting the oblique portion (760) and the second parallel conductor portion (720), and an S-shaped portion (790) connecting the first curved portion (750) arranged in the first layer and the oblique portion (760) arranged in the second layer.

13. A motor winding according to any preceding claim, further comprising A first coil contact wire (800), a second coil contact wire (900), and a third coil contact wire (1000), each of the first coil contact wire (800), the second coil contact wire (900), and the third coil contact wire (1000) comprising a parallel wire portion (820, 920, 1020) connected to a hanging portion (830, 930, 1030), and the parallel wire portion (820, 920, 1020) is arranged in a third layer of the winding; in, Each of the overhanging portions (830, 930, 1030) of the first, second and third coil contact wires (800, 900, 1000) comprises an extension portion (840, 940, 1040) arranged in a fourth layer of the winding adjacent to the third layer and extending from the winding, a first bent portion (850, 950, 1050) connected to the extension portion (840, 940, 1040), an oblique line portion (860, 960, 1060) connected to the first bent portion (850, 950, 1050), a first bent portion (850, 950, 1050) connected to the first bent portion (850, 950, 1050), and a second bent portion (870, 970, 1070) connecting the oblique line portion (860, 960, 1060) and the parallel wire portion (820, 920, 1020); wherein the parallel wire portion (820) of the first coil contact wire (800) is configured to be embedded in the fourth slot, the parallel wire portion (920) of the second coil contact wire (900) is configured to be embedded in the fifth slot, and the parallel wire portion (1020) of the third coil contact wire (1000) is configured to be embedded in the sixth slot; The extension portion (840) of the first coil contact wire (800) contacts the fourth coil contact wire (1100), and the fourth coil contact wire (1100) is connected to a parallel wire portion in a first slot arranged in a third layer of the winding; The extension portion (940) of the second coil contact wire (900) contacts the fifth coil contact wire (1200), and the fifth coil contact wire (1200) is connected to a parallel wire portion in the second slot arranged in the third layer of the winding; The extension portion (1040) of the third coil contact wire (1000) contacts the sixth coil contact wire (1300), and the sixth coil contact wire (1300) is connected to a parallel wire portion in a third slot arranged in a third layer of the winding; The oblique portions (860, 960, 1060) of the first, second and third coil contact wires (800, 900, 1000) include an S-shaped portion (890, 990, 1090) arranged between the third layer and the fourth layer, so that the fifth and sixth coil contact wires (1200, 1300) both cross the oblique portion (860) of the first coil contact wire (800), and the sixth coil contact wire (1300) crosses the oblique portion (960) of the second coil contact wire (900).

14. A motor, comprising: a stator having a plurality of slots, and; A winding as claimed in any one of claims 1 to 13.

15. A method for manufacturing a motor winding, the method comprising the following steps: A wire material is made into a first wire (100), a second wire (200) and a third wire (300), each of the first wire (100), the second wire (200) and the third wire (300) comprising two parallel wire portions connected by a hanging portion; The first conductive wire (100), the second conductive wire (200), and the third conductive wire (300) are embedded in a plurality of slots of the rotor or stator of the motor in a prescribed order, such that: A first parallel conductor portion of the first conductor (100) is embedded in a first groove among the plurality of grooves; A first parallel conductor portion of the second conductor (200) is embedded in a second groove among the plurality of grooves adjacent to the first groove; The first parallel conductor portion of the third conductor (300) is embedded in a third groove among the plurality of grooves which is adjacent to the second groove and different from the first groove; The second parallel conductor portion of the first conductor (100) is embedded in a fourth groove among the plurality of grooves which are different from the first groove, the second groove and the third groove; The second parallel conductor portion of the second conductor (200) is embedded in a fifth slot among the plurality of slots which is adjacent to the fourth slot and different from the third slot; as well as The second parallel conductor portion of the third conductor (300) is embedded in a sixth slot among the plurality of slots which is adjacent to the fifth slot and different from the fourth slot; It is characterized in that the wire forming is carried out as follows: The overhang portion of the first conductor (100) comprises a first U-shaped bend (190) arranged in a direction perpendicular to a plane defined by two parallel conductor portions (110, 120), the first U-shaped bend (190) being formed to accommodate a crossing portion of the overhang portion (230) of the second conductor (200) and a crossing portion of the overhang portion (330) of the third conductor (300); The overhanging portion of the second conductor (200) comprises a second U-shaped bend (290) arranged in a direction perpendicular to a plane defined by two parallel conductor portions (210, 220), the second U-shaped bend (290) being formed to accommodate a crossing portion of the overhanging portion (330) of the third conductor (300), and The overhanging portion (330) of the third conductive line (300) is contained within a plane defined by two parallel conductive line portions (310, 320).

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