Layout structure of flat wire winding with equal sectional area and high slot fullness rate

Abstract

The invention discloses an equal-sectional-area high-slot-fullness-rate concentrated flat wire winding layout structure. The flat wire winding layout structure comprises a plurality of flat wire windings and a stator core with non-rectangular stator slots, each flat wire winding is wound on a respective stator core tooth part in the stator core and arranged in the same manner, and the width of each layer of flat wires of each flat wire winding is increased layer by layer from the narrower side to the wider side of the stator slot of the stator core. The thickness of each layer of flat wire is increased layer by layer from the wider side to the narrower side of a stator slot of the stator core, the total sectional area of each layer of flat wire is the same, and the wire ends of the flat wire windings are mutually connected at the end part of the motor. According to the invention, the slot fill factor of the flat wire winding in the non-rectangular slot can be effectively improved, the problem of low space utilization rate is solved, the efficiency and power density of the motor are further improved, the current densities at different positions of the conductor in the slot are basically the same, the insulation failure caused by too high local temperature rise is avoided, and the reliability of the winding can be effectively improved.

Description

Technical Field

[0001] The invention relates to a flat wire winding layout structure, relates to the technical field of motors, and in particular to a flat wire winding layout structure with equal cross-sectional area and high slot fill rate. Background Art

[0002] Flat wire windings have been widely used in electric vehicles and large industrial fields due to their advantages such as high slot fill rate, low winding loss, good thermal conductivity and low electromagnetic noise. The cross-section of the flat wire winding is rectangular, and it can be arranged more closely when arranged, thereby improving the slot fill rate of the motor and achieving higher power density. When designing flat wire motors, rectangular slot structures are more often used. This structure may lead to uneven magnetic flux distribution in the stator teeth. The magnetic flux at the tooth top is significantly larger than that at the tooth root, which may cause local magnetic saturation or waste of space. However, because its cross-section is rectangular, the layout structure of its winding is not as adaptable to different tooth slot types as round wire. When it is arranged in non-rectangular slots such as pear-shaped slots and trapezoidal slots, it is very easy to waste space. Although some literature has proposed a layout structure of flat wire windings with unequal areas to improve the slot fill rate, due to the change in the cross-sectional area of ​​the conductor, the current density at different positions in the slot is different, which is easy to cause local temperature increase. At the same time, existing flat wire motors mostly use hairpin windings, which require welding to connect multiple flat wire conductors. The number of solder joints on the windings increases significantly, leading to increased process difficulty and reduced motor reliability. Therefore, it is necessary to study new winding layout structures to increase the slot fill rate of flat wire windings in non-rectangular slots, so as to achieve a motor design solution with high efficiency, high power density, high reliability and low processing difficulty. Summary of the invention

[0003] In order to solve the problems existing in the background technology, the present invention provides a layout structure of a flat wire winding with a constant cross-sectional area and a high slot filling rate. The present invention improves the slot filling rate of the flat wire winding in a non-rectangular slot while ensuring that the current density of the conductor in the slot is evenly distributed, and reduces the number of welding points of the motor, thereby improving the power density and reliability of the motor.

[0004] The technical solution adopted by the present invention is:

[0005] The high slot-filling rate concentrated flat wire winding layout structure of equal cross-sectional area of ​​the present invention comprises a plurality of flat wire windings and a stator core with non-rectangular stator slots, each flat wire winding is respectively wound on a stator core tooth portion of the stator core and arranged in the same manner, the width of each layer of flat wire of each flat wire winding increases layer by layer from the narrower side to the wider side of the stator slot of the stator core, the thickness of each layer of flat wire of each flat wire winding increases layer by layer from the wider side to the narrower side of the stator slot of the stator core, and the total cross-sectional area of ​​each layer of flat wire of each flat wire winding is the same; the wire ends of each flat wire winding are connected to each other at the end of the motor by welding or the like. The arrangement of each flat wire winding is the same, that is, the number of winding layers of the flat wire winding on each stator core tooth portion and the width and thickness of the corresponding layer winding and the arrangement position are the same.

[0006] The flat wire winding is a continuous flat wire. The continuous flat wire winding wound on the same stator core tooth portion has different width and thickness dimensions at different positions along the line. The flat wire wound around the stator core tooth portion and located in the same layer is approximately an elongated rectangular parallelepiped with uniform width and thickness dimensions. The bending position between each two adjacent layers of flat wires is located at the same side end of the stator core tooth portion and is approximately trapezoidal. The width and thickness of the flat wire at the bending position between adjacent layers of flat wires gradually change along the line. The size of the cross-section of one end at the bending position between adjacent layers of flat wires is the same as the cross-section size of a layer of flat wire on the narrower side of the stator slot close to the stator core, and the size of the cross-section of the other end at the bending position between adjacent layers of flat wires is the same as the cross-section size of a layer of flat wire on the wider side of the stator slot close to the stator core.

[0007] The stator slots of the stator core are semi-closed slots, specifically parallel-tooth flat-bottom slot structures, the bottom edges of the stator slots are perpendicular to the stator tooth bodies, the stator slots are wider near the stator core yoke, and narrower at the slot openings away from the stator core yoke, the width of a layer of flat wire closest to the stator core yoke in the flat wire winding is the largest and the thickness is the smallest, the width of several layers of flat wires gradually decreases and the thickness gradually increases from the position near the stator core yoke to the slot opening, and the width of a layer of flat wire closest to the slot opening of the stator slot is the smallest and the thickness is the largest.

[0008] The flat wire winding is symmetrically distributed in the stator slots on both sides of the stator core tooth portion along a cross section perpendicular to the axial direction of the stator core. The total area of ​​the two symmetrical cross sections of each layer of flat wires in the flat wire winding is the same, but the width and thickness are different. The two symmetrical cross sections of each layer of flat wires are approximately rectangular, with the long sides perpendicular to the stator tooth body and parallel to the bottom edge of the stator slot.

[0009] The stator core is a spliced ​​stator, specifically a block tooth structure, a tooth yoke separation structure or a combination of a block tooth structure and a tooth yoke separation structure. Adjacent stator core teeth of the stator core are integrally formed through a plurality of connecting strips.

[0010] The flat wire winding is wound in a vertical winding manner during processing, and the flat wire winding on a single stator core tooth portion is wound and formed at one time by a winding machine.

[0011] The stator slot wall of the stator core is coated with a slot insulation layer.

[0012] The surface of the flat wire winding is coated with a layer of winding insulation paint film.

[0013] The beneficial effects of the present invention are:

[0014] 1) The present invention can improve the slot fill rate of the flat wire winding in the non-rectangular slot of the parallel tooth structure motor, solve the problem of low space utilization, and combine the advantages of uniform parallel tooth magnetic circuit distribution and high slot fill rate of the flat wire winding, so as to improve the efficiency and power density of the motor.

[0015] 2) The present invention maintains the same cross-sectional area of ​​conductors in different layers of the flat wire winding, avoids the problem of uneven current density distribution in the slot caused by changes in the conductor area, and ensures that the current density of the conductor at different positions in the slot is basically the same; compared with the existing layout of flat wire windings with unequal areas, it can reduce the problem of uneven heat generation positions in the slot to a certain extent, and avoid local excessive temperature rise leading to insulation failure of the winding.

[0016] 3) The winding on a single stator tooth of the present invention is formed by a winding machine at one time, which effectively reduces the number of welding points, can effectively improve the reliability of the winding, and reduce the difficulty of welding processing.

[0017] 4) The present invention adopts a spliced ​​stator structure, which has low winding difficulty and reduces the risk of copper wire damage during the winding process. At the same time, it eliminates the restriction of the flat wire winding width on the slot size caused by winding from the slot position, and can use a semi-closed slot to further reduce the torque pulsation of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the stator structure of the high slot-filling-rate concentrated flat wire winding with equal cross-sectional area in the embodiment of the present invention;

[0019] Figure 2 It is a cross-sectional view of the layout structure of the concentrated rectangular wire winding with equal cross-sectional area and high slot filling rate of the present invention;

[0020] Figure 3 is a top view of the stator structure of the flat wire winding of the present invention in an embodiment;

[0021] Figure 4 is a bottom view of the stator structure of the flat wire winding of the present invention in an embodiment;

[0022] Figure 5A schematic diagram of the layout structure of the flat wire winding of the present invention on a single stator tooth;

[0023] Figure 6 is a cross-sectional view of a flat wire winding of the present invention on a single stator core tooth;

[0024] Figure 7 It is a schematic diagram of a straight line segment of a flat wire winding of the present invention;

[0025] In the figure: 1. stator core teeth, 2. stator core yoke, 3. slot insulation layer, 4. flat wire winding, 5. winding insulation paint film. DETAILED DESCRIPTION

[0026] In order to describe the technical solutions in the embodiments of the invention more clearly and accurately, the invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the 18-slot concentrated flat wire winding motor stator core used in the embodiment of the present invention, the stator of the present invention adopts a tooth yoke separation structure, during processing, the flat wire winding 4 is first wound on the stator core tooth part 1, and then spliced ​​with the stator core yoke part 2 to form a complete stator structure after winding. The stator core is a spliced ​​stator, specifically a block tooth structure, a tooth yoke separation structure, or a combination of a block tooth structure and a tooth yoke separation structure. Each adjacent stator core tooth part 1 of the stator core is integrally formed by a plurality of connecting strips. The stator core includes 18 flat wire windings 4 and a stator core with 18 non-rectangular stator slots. Each flat wire winding 4 is wound on a stator core tooth 1 in the stator core and arranged in the same manner. The width of each layer of flat wire of each flat wire winding 4 increases layer by layer from the narrower side to the wider side of the stator slot of the stator core. The thickness of each layer of flat wire of each flat wire winding 4 increases layer by layer from the wider side to the narrower side of the stator slot of the stator core. The total cross-sectional area of ​​each layer of flat wire of each flat wire winding 4 is the same. The wire ends of each flat wire winding 4 are connected to each other at the end of the motor by welding or the like. The arrangement of each flat wire winding 4 is the same, that is, the number of winding layers of the flat wire winding 4 on each stator core tooth 1, the width and thickness of the corresponding layer winding, and the arrangement position are the same.

[0028] The stator slot of the stator core is a semi-closed slot, specifically a parallel tooth flat bottom slot structure, the bottom edge of the stator slot is perpendicular to the stator tooth body, the stator slot is wider near the stator core yoke 2, and narrower at the slot position away from the stator core yoke 2. The flat wire layer closest to the stator core yoke 2 in the flat wire winding 4 has the largest width and the smallest thickness. The width of several layers of flat wire gradually decreases and the thickness gradually increases from the position close to the stator core yoke 2 to the slot position, and the width of the layer of flat wire closest to the slot position of the stator slot is the smallest and the thickness is the largest. A slot insulation layer 3 is coated on the stator slot wall of the stator core.

[0029] like Figure 5 As shown, the flat wire winding 4 is a continuous flat wire, and the width and thickness of the continuous flat wire winding 4 wound on the same stator core tooth portion 1 are not completely the same at different positions along the line. The flat wire of the flat wire winding 4 wound around the stator core tooth portion 1 and located in the same layer is approximately in the shape of an elongated rectangular parallelepiped with uniform width and thickness. The bending position between each two adjacent layers of flat wires is located at the same side end of the stator core tooth portion 1 and is approximately in the shape of a trapezoid. The width and thickness of the flat wire at the bending position between adjacent layers of flat wires gradually change along the line. The size of the cross-section of one end at the bending position between adjacent layers of flat wires is the same as the cross-section size of a layer of flat wire on the narrower side of the stator slot close to the stator core, and the size of the cross-section of the other end at the bending position between adjacent layers of flat wires is the same as the cross-section size of a layer of flat wire on the wider side of the stator slot close to the stator core. The flat wire winding 4 can be viewed geometrically as an arrangement of approximately slender rectangular solids with uniform width and thickness and approximately trapezoidal solids with gradually increasing width and thickness, arranged alternately.

[0030] The flat wire winding 4 is located on both sides of the stator core tooth 1 and is symmetrical with respect to the tooth body. The width and thickness of the flat wires in the same layer are the same, and the width and thickness of the flat wires in different layers are different, but the cross-sectional area is the same. The width and thickness of the flat wire are adjusted to fill the entire stator slot as much as possible. Since the stator slot is wider near the stator core yoke 2, the closer to the stator core yoke 2, the wider the flat wire is, the thinner the thickness is; the stator slot is narrower near the slot opening, and the closer to the slot opening, the narrower the flat wire is, the thinner the flat wire is, and the thicker the flat wire is. The flat wire closest to the slot opening has the smallest width and the largest thickness.

[0031] The flat wire winding 4 is symmetrically distributed in the stator slots on both sides of the stator core tooth portion 1 along the cross section perpendicular to the axial direction of the stator core. The total area of ​​the two symmetrical cross sections of each layer of the flat wire of the flat wire winding 4 is the same, but the width and thickness are different. The two symmetrical cross sections of each layer of the flat wire are approximately rectangular, and the long side is perpendicular to the stator tooth body and parallel to the bottom edge of the stator slot. The flat wire winding 4 is wound in a vertical winding manner during processing. The flat wire winding 4 on a single stator core tooth portion 1 is wound and formed at one time by a winding machine. The surface of the flat wire winding 4 is coated with a layer of winding insulation paint film 5.

[0032] like Figure 5 , Figure 6 and Figure 7 As shown, the number of layers of the flat wire winding 4 in the stator slot of the embodiment of the present invention is selected to be 8, the thickness of the slot insulation layer 3 is 0.3mm, and the thickness of the winding insulation paint film 5 of the flat wire winding 4 is 0.1mm. A right-angled trapezoidal area that can be used for arranging the flat wire winding 4 is cut out along the cross section of the stator slot. It is assumed that the length of its upper base is D1, the length of its lower base is D2, the height is H, and the thickness of the winding insulation paint film 5 is set to d. The layer of flat wire closest to the slot position is selected as the first layer of flat wire. It is assumed that its thickness is h1, the width is w1, and the cross-sectional area is S Δ Starting from the first layer of flat wire towards the direction close to the stator core yoke 2, the second to n layers of windings are similarly deduced, and the thickness of the i-th layer of winding is h i , with a width of w i , the cross-sectional area is S Δ . Then the following equation is satisfied:

[0033]

[0034] h1*w1=h i *w i =S Δ

[0035] When designing the arrangement of the flat wire winding 4, in order to simplify the calculation, after the thickness of the winding insulation paint film 5 is reserved at the short sides of both sides, the two short sides of the flat wire cross section are as close as possible to the edge of the trapezoidal arrangement area, and the thickness of the winding insulation paint film 5 at the long side of the flat wire in the trapezoid is only 0.1mm, that is, there is a 0.2mm winding insulation paint film 5 between two adjacent layers of flat wires. Therefore, the following relationship between width and thickness can be obtained with the help of geometric relationship:

[0036]

[0037] After joint solution, it can be obtained that the thickness of the flat wire of the first layer in this embodiment is 2.46mm, the width is 5.12mm, and the cross-sectional area of ​​each layer of flat wire is 12.63mm 2 , the slot fill rate reached 73.22%.

[0038] The flat wire winding 4 on a single stator core tooth 1 is wound by a continuous flat wire, and the width and thickness of the flat wire at different positions along the wire are not completely the same. The winding starts from the first layer of flat wire near the slot position, and the width and thickness of the first layer of flat wire segments corresponding to both sides of the stator core tooth 1 remain uniform. The first layer of flat wire is wound around the stator core tooth 1 for one circle, and then the width of the flat wire at the end gradually increases and the thickness gradually decreases. When the end of the second layer is wound and connected to the corner of the slot position, the width and thickness change to the same as the width and thickness of the second layer of flat wire calculated above, and the subsequent flat wire change trend is similar.

[0039] By changing the position of the mold when processing the flat wire used for winding, the flat wire with the above-mentioned regular changes is processed. When winding, it is necessary to ensure that the layer-changing section of the flat wire winding 4 is located at the end of the motor, and the flat wires in the stator slots are all regular rectangular sections with constant width and thickness. Therefore, it is necessary to plan the required length of each layer of flat wire and the length of the layer-changing section at the end of the winding according to the winding path adopted.

[0040] The flat wire winding 4 in the embodiment of the present invention is a continuous flat wire on a single stator core tooth 1, which is wound once by a winding machine in a vertical winding manner. The outlet and inlet ends of the flat wire winding 4 extend from the end of the stator, and the bridge wire and lead wire can be arranged according to the actual needs of the motor, and a complete flat wire concentrated winding is formed by welding.

[0041] The concentrated flat wire winding layout structure of equal cross-sectional area of ​​the present invention can realize the close arrangement of the flat wire winding 4 in the non-rectangular slot while ensuring the uniform distribution of current density at various locations in the stator slot, effectively improve the slot fill rate of the flat wire winding 4 in the non-rectangular slot, and help to improve the reliability and power density of the flat wire motor.

Claims

1. A high slot-filling ratio concentrated flat wire winding layout structure with equal cross-sectional area, characterized in that: The invention comprises a plurality of flat wire windings (4) and a stator core with a non-rectangular stator slot. Each flat wire winding (4) is respectively wound on a stator core tooth portion (1) in the stator core and arranged in the same manner. The width of each layer of flat wire in each flat wire winding (4) increases layer by layer from the narrower side to the wider side of the stator slot of the stator core. The thickness of each layer of flat wire in each flat wire winding (4) increases layer by layer from the wider side to the narrower side of the stator slot of the stator core. The total cross-sectional area of ​​each layer of flat wire in each flat wire winding (4) is the same. The wire ends of each flat wire winding (4) are connected to each other at the end of the motor.

2. The high slot fill rate concentrated flat wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: The flat wire winding (4) is a continuous flat wire. The flat wire of the flat wire winding (4) wound around the stator core tooth portion (1) and located in the same layer is in the shape of a rectangular parallelepiped with uniform width and thickness. The bending position between each two adjacent layers of flat wires is located at the same side end of the stator core tooth portion (1) and is in the shape of a trapezoid. The size of the cross section of one end at the bending position between the adjacent layers of flat wires is the same as the size of the cross section of a layer of flat wire on the narrower side of the stator slot of the stator core, and the size of the cross section of the other end at the bending position between the adjacent layers of flat wires is the same as the size of the cross section of a layer of flat wire on the wider side of the stator slot of the stator core.

3. The high slot fill rate concentrated flat wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: The stator slots of the stator core are semi-closed slots. The stator slots are wider at positions close to the stator core yoke (2) and narrower at slot openings away from the stator core yoke (2). The layer of flat wire closest to the stator core yoke (2) in the flat wire winding (4) has the largest width and the smallest thickness. The width of the layers of flat wire gradually decreases and the thickness gradually increases from the position close to the stator core yoke (2) to the slot opening. The layer of flat wire closest to the stator core yoke (2) has the smallest width and the largest thickness.

4. The high slot fill rate concentrated flat wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: The flat wire winding (4) is symmetrically distributed in the stator slots on both sides of the stator core tooth portion (1) along a cross section perpendicular to the axial direction of the stator core, and the total area of ​​the two symmetrical cross sections of each layer of flat wires of the flat wire winding (4) is the same.

5. The high slot fill rate concentrated rectangular wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: The stator core is a spliced ​​stator, specifically a block tooth structure, a tooth yoke separation structure or a combination of a block tooth structure and a tooth yoke separation structure.

6. The high slot fill rate concentrated rectangular wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: The flat wire winding (4) is wound in a vertical winding manner during processing, and the flat wire winding (4) on a single stator core tooth portion (1) is wound into shape once by a winding machine.

7. The high slot fill rate concentrated rectangular wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: A slot insulation layer (3) is coated on the stator slot wall of the stator core.

8. The high slot fill rate concentrated rectangular wire winding layout structure with equal cross-sectional area according to claim 1 is characterized in that: The surface of the flat wire winding (4) is coated with a layer of winding insulation paint film (5).

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