Fractional-slot concentrated winding flat wire motor and winding method of winding of fractional-slot concentrated winding flat wire motor

Abstract

The invention belongs to the field of flat wire motors, and relates to a fractional-slot concentrated winding flat wire motor and a winding method of windings of the fractional-slot concentrated winding flat wire motor. A stator structure in the fractional-slot concentrated winding flat wire motor comprises a stator core, slot insulation and a flat wire winding, the flat wire winding is a fractional-slot concentrated winding with the span being 1, the flat wire winding adopts a rectangular wire, the wide edge of the rectangular wire is parallel to teeth, and the narrow edge of the rectangular wire is bent; a wire is wound into two layers in the groove height direction to form a winding element, a plurality of winding elements are connected end to end to form a coil, and a plurality of coils are connected to form a flat wire winding; the coil is wound in multiple layers in the tooth height direction and the groove width direction, and the layer number N1 in the tooth height direction is an even number. The stator iron core and the flat wire winding are insulated through slot insulation.

Description

Technical Field

[0001] This invention belongs to the field of flat wire motors and relates to a fractional slot concentrated winding flat wire motor and a winding method for the winding. Background Technology

[0002] Flat wire motor armature windings offer advantages such as high slot fill factor and good heat dissipation, gradually becoming a development trend for future high-power motors. Currently, most flat wire motors use distributed windings, where the coil span is greater than 1, and multiple coils overlap at the winding ends, resulting in a longer end length and circumference, increased resistance, and lower motor efficiency. Fractional slot concentrated windings, on the other hand, have a coil span of 1, with each coil wound on a single tooth, and no overlap at the winding ends. This significantly shortens the winding circumference and end length, greatly reducing winding resistance and significantly improving motor efficiency. However, unlike multi-layer flat wire distributed windings (1 turn per element), when using flat wire in fractional slot concentrated windings, it is crucial to ensure that the input and output wires of each coil are on the outermost edge of the coil to avoid interference between coils, which can lead to a decrease in slot fill factor and wiring difficulties.

[0003] In order to place the winding input and output wires on the outermost layer of the winding, most fractional slot concentrated windings currently adopt the method shown in the attached figure. Figure 1 , 2 The stator structure shown is a flat wire vertically wound stator, where the wide side of the flat wire winding is parallel to the bottom of the slot and the wide side is bent. Each winding has multiple turns distributed in a single layer along the slot height. This structure has the following problems: 1. To facilitate winding assembly, the stator core must adopt an open slot design, as shown in the attached figure. Figure 1 As shown, this will lead to a significant increase in motor cogging torque and rotor eddy current losses. Alternatively, a stator core design with separate teeth and yokes, where each stator tooth is individually machined and inserted into a pre-formed coil, and then the stator tooth with windings is finally connected to the yoke core, greatly increases the machining difficulty and easily causes uneven air gaps. (See attached image) Figure 2 The diagram shows a structure with a tooth-yoke separation design and a flat wire winding inserted into the stator teeth. 2. Due to the difficulty in bending the wide side, a special mold is required for pre-forming. A top view of the formed coil is attached. Figure 3 As shown, this leads to increased manufacturing costs; 3. The winding cross-sectional view is attached. Figure 4 As shown, due to the small thickness of the varnish film on the narrow side of the flat wire and the large difference in circumference between the inner and outer circles at the bend of the winding, the inner circle is compressed and deformed, and the outer circle is stretched and deformed. Both the inner and outer circles are deformed, and the varnish film cracking can easily cause insulation failure.

[0004] Due to the constraints of the above-mentioned issues, most current fractional-slot concentrated winding motor stators still use a round wire structure. Summary of the Invention

[0005] Purpose of the invention: To provide a fractional slot concentrated winding flat wire motor and a winding method for the winding.

[0006] Technical solution: A fractional-slot concentrated winding flat wire motor, the stator structure of the fractional-slot concentrated winding flat wire motor includes: a stator core 1, slot insulation 2, and flat wire winding 3, wherein the flat wire winding 3 is a fractional-slot concentrated winding with a span of 1, the flat wire winding 3 uses rectangular conductors, wherein the wide side of the rectangular conductor is parallel to the teeth, and the narrow side is bent; a single conductor is wound in two layers along the slot height direction to form a winding element, multiple winding elements are connected end to end to form a coil, multiple coils are connected to form the flat wire winding 3; the coil is wound in multiple layers along the tooth height direction and the slot width direction, the number of layers N1 along the tooth height direction is an even number; the stator core 1 and the flat wire winding 3 are insulated from each other by the slot insulation 2.

[0007] Furthermore, the greatest common divisor of the number of slots Z and the number of pole pairs P of the stator core 1 is t, and the number of slots z0 of each unit motor satisfies The number of magnetic pole pairs p0 satisfies The number of slots z0 and the number of pole pairs p0 satisfy the combination that constitutes a fractional slot concentrated winding.

[0008] Furthermore, the stator core 1 adopts a parallel tooth flat-bottom groove structure, with the bottom of the groove being two intersecting planes, and the two bottom planes of the groove being perpendicular to the adjacent tooth sides.

[0009] Furthermore, slot insulation 2 is insulating paper.

[0010] Furthermore, two adjacent winding elements on the same tooth are connected end to end to form a coil.

[0011] Furthermore, the stator core 1 is made of silicon steel sheets.

[0012] Furthermore, the fractional-slot concentrated winding flat wire motor has a rotating magnetic pole structure, and the stator is an armature assembly.

[0013] A winding method for a fractional-slot concentrated winding flat wire motor winding, characterized in that it includes: Step 1: Wind multiple winding elements sequentially along the tooth height direction. Each winding element is wound bidirectionally from the middle of the wire using a single wire. After multiple winding elements are fully wound along the tooth height direction, connect the beginning and end of two adjacent winding elements to form a coil. The wire is a rectangular wire, with the wide side parallel to the tooth and the narrow side bent. Step 2: Connect the coils belonging to the same phase according to the winding diagram to form a phase winding.

[0014] Beneficial effects: The present invention enables the fractional slot concentrated winding to adopt a narrow-side bend shape, so that the winding inlet and outlet are both on the outermost layer of the winding. Because the narrow-side bend shape is easy to achieve, there is no need for winding pre-forming. The stator core does not need to adopt tooth-yoke separation or open slot design. The difference in circumference between the inner and outer diameters of the winding element is greatly reduced, which reduces the deformation of the inner and outer diameters at the bend of the winding and greatly reduces the insulation damage caused by the bend of the flat wire winding. Attached Figure Description Appendix Figure 1 Partial view of the structure of the open slot stator assembly of a pre-existing fractional slot concentrated winding flat wire motor; Appendix Figure 2 Partial view of the existing fractional slot concentrated winding flat wire motor tooth-yoke separated stator assembly structure; Appendix Figure 3 Wide-side curved fractional slot concentrated winding element; Appendix Figure 4 Cross-sectional view of the stator assembly with wide-side curved fractional slot concentrated winding; Appendix Figure 5 The stator core cross-sectional view used in this invention; Appendix Figure 6 Schematic diagram of the first-turn coil winding method of the present invention; Appendix Figure 7 A partial cross-sectional view of the stator assembly after the first flat wire (layers 1 and 2) of the winding of the present invention has been wound; Appendix Figure 8 A partial view of the stator assembly of the winding after the first flat wire (layers 1 and 2) of the winding of the present invention has been wound; Appendix Figure 9 A partial effect diagram of the completed winding of one tooth according to the present invention; Appendix Figure 10 A structural diagram of a 12-slot stator assembly wound using the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0016] In the description of this invention, it should be understood that the terms "center", "axial", "vertical", "upper", "lower", "upper end", "bottom end", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0017] The purpose of this invention is to provide a multi-layer flat wire stator structure with fractional slot concentrated winding that adopts a narrow-side bend and does not require pre-forming. It can be arranged in multiple layers along the tooth height and slot width directions. At the same time, the input and output wires of each coil are located on the outermost side of the coil to facilitate wiring and avoid the decrease in slot fill factor caused by interference between coils due to wire crossing.

[0018] A flat wire stator structure for a fractional slot concentrated winding motor includes a stator core 1, slot insulation 2, and flat wire windings 3.

[0019] The greatest common divisor of the number of slots Z and the number of pole pairs P of stator core 1 is t, that is, the motor has t unit motors, and the number of slots z0 of each unit motor is ( ) and the number of magnetic pole pairs p0 ( ( ), should conform to the requirements of forming a fractional slot concentrated winding. The stator core adopts a parallel tooth flat-bottom slot structure, with the bottom of the slot consisting of two intersecting planes, and each of the two bottom planes is perpendicular to its adjacent tooth. A cross-sectional view of the stator core is attached. Figure 5 As shown.

[0020] Slot insulation 2 is insulating paper, which is placed on the bottom pole teeth of the stator slot. Its function is to separate the winding from the iron core and prevent short circuit between the winding and the iron core.

[0021] Flat wire winding 3 is a fractional slot concentrated winding with a span of 1. Flat wire winding 3 uses rectangular conductors (i.e., flat wire). The wide side of flat wire winding 3 is parallel to the teeth, and the narrow side is bent. This makes the winding bending easy, without the need for special tooling or pre-forming. On the other hand, the difference in length between the inner and outer circles at the bend of the winding is greatly reduced, which greatly reduces the tensile deformation at the outer circle and the compressive deformation at the inner circle. Moreover, the deformation of the inner and outer circles is located in the plane of the wide side of the conductor. The conductor itself has a thick enamel film and is not easy to crack, which greatly reduces the winding insulation failure caused by bending. Flat wire winding 3 can be wound in multiple layers along the tooth height direction and the slot width direction. The number of layers N1 along the tooth height direction must be even. Each layer along the slot height direction can also be wound in multiple layers along the slot width direction, and the number of layers N2 can be either odd or even.

[0022] Method for winding flat wire stator of fractional slot concentrated winding motor: One wire is used for winding every two layers along the slot height. Assuming the average length per turn of the winding is *a*, the required length of each wire is L = 2N²a. The winding method for the first turn is attached. Figure 1 The winding begins from the middle of the conductor, with one end close to the bottom of the slot and the other end a distance from the bottom of the slot equal to the width of the conductor. The length of both ends of the winding is approximately L / 2. The other layers along the slot width direction are wound in two separate layers from both ends of the winding along the tooth height direction, as shown in the attached diagram. Figure 5 As shown in the attached diagram, the completed winding effect of layers 1 and 2 along the slot height direction is as follows. Figure 6 , 7 8. The remaining windings are grouped into sets of two layers, and the winding method is similar to that described above. (Appendix) Figure 9 This is a structural diagram of a concentrated winding with 6 layers along the tooth height, completed on a single tooth. (Attached) Figure 10 This diagram shows the structure of a 12-slot stator assembly constructed using the windings of this invention. After winding, the multiple windings on the same tooth are connected end-to-end to form a single winding. The multiple windings of each phase of a motor distributed across multiple unit motors can be connected in series or parallel according to usage requirements.

[0023] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A fractional-slot concentrated-winding flat wire motor, characterized by, The stator structure in fractional-slot concentrated winding flat wire motor includes a stator core, slot insulation and flat wire winding, wherein the flat wire winding is fractional-slot concentrated winding with a span of 1, and the flat wire winding adopts rectangular wire, wherein the wide side of the rectangular wire is parallel to the tooth, and the narrow side is bent; one wire is used to wind two layers along the slot height direction to form a winding element, a plurality of winding elements are connected end to end to form a coil, and a plurality of coils are connected to form a flat wire winding; the coil is wound in multiple layers along the tooth height direction and the slot width direction, and the number of layers N1 along the tooth height direction is even; the stator core and the flat wire winding are insulated by the slot insulation.

2. The fractional-slot concentrated-winding flat motor of claim 1, wherein The greatest common divisor of the slot number Z of the stator core and the pole pair number P is t, and the slot number z0 of each unit motor satisfies , the pole pair number p0 satisfies , and the slot number z0 and the pole pair number p0 satisfy a combination constituting a fractional-slot concentrated winding.

3. The fractional-slot concentrated-winding flat motor of claim 2, wherein The stator core adopts parallel-tooth flat-bottom slot structure, the slot bottom is two intersecting planes, and the two slot bottom planes are perpendicular to the adjacent tooth side surfaces.

4. The fractional-slot concentrated-winding flat motor of claim 3, wherein The slot insulation is insulating paper.

5. The fractional-slot concentrated-winding flat motor of claim 4, wherein The adjacent two winding elements on the same tooth are connected end to end to form a coil.

6. The fractional-slot concentrated-winding flat motor of claim 5, wherein The stator core is a silicon steel sheet.

7. The fractional-slot concentrated-winding flat motor of claim 6, wherein The fractional-slot concentrated winding flat wire motor is a rotating magnetic pole type structure, and the stator is an armature assembly.

8. A method of winding a fractional-slot concentrated-winding flat wire motor winding, characterized by, Comprise: Step 1: sequentially winding a plurality of winding elements along the tooth height direction, each winding element is bidirectionally wound from the middle position of the wire using one wire; After the plurality of winding elements are wound along the tooth height direction, the ends of the adjacent two winding elements are connected to form a coil, wherein the wire is rectangular wire, and the wide side of the wire is parallel to the tooth, and the narrow side is bent; Step 2: connecting the coils belonging to the same phase according to the winding diagram to form a phase winding.

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