Stator structure with rectangular wire windings
The stator structure with inner blocks and insulating sheets addresses the issue of wire deformation in rectangular windings, enhancing manufacturing yield and reducing defects by ensuring proper fit and insulation.
Patent Information
- Application Number
- JP2024003568U
- Authority / Receiving Office
- JP · JP
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2024-12-26
- Estimated Expiration
- 2034-10-29
Smart Images
Figure 0003249612000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a stator structure, and more particularly to a stator structure applied to a group of rectangular wire windings. [Background technology]
[0002] The basic structure of a motor is equipped with a stator and a rotor, which converts electrical energy into rotational kinetic energy through the principle of electromagnetic induction, and outputs torque. The output effect of the motor is determined by the interaction of the magnetic field between the stator and the rotor. Summary of the Invention [Problem to be solved by the invention]
[0003] The stator core has a structure including an annular yoke and a plurality of teeth arranged in a circumferential direction of the yoke, a radially extending slot is formed between each pair of adjacent teeth, and the ends of the pair of teeth have boot portions extending in a circumferential direction, and a slot opening of the slot is formed. The boot portion acts to collect magnetic force, and the wider the range of the boot portion extending in the circumferential direction, the more magnetic flux the stator core can tolerate. Therefore, many of the boot portions formed at the slot opening have a narrow and flat shape and low strength.
[0004] The stator windings of a three-phase induction motor are usually formed of rectangular copper wires called hairpin windings. Compared to conventional windings with a circular cross section, flat wire (also called rectangular wire) windings are used to increase the space factor and allow for larger currents, while also providing greater heat dissipation properties when operating electric machines at high power density and high efficiency.
[0005] When assembling a hairpin winding, first, multiple flat copper wires are sequentially curved to form a hairpin wire. Next, multiple hairpin wires are stacked in the radial direction and arranged in a ring shape in the circumferential direction based on the wiring diagram of the winding. Next, the open ends of the wires are inserted into the slots of the stator core along the axial direction. Then, the open ends of the hairpins are twisted, cut flat, welded, and other processes to form a flat wire winding group. After the formed hairpin wire is inserted into the stator core, the wire located in the slot is further expanded along the radial direction of the iron core due to the properties of the copper material and the geometric tolerance when bending and twisting the wire.
[0006] In order to ensure insulation within the core slot of the stator, after forming the rectangular wire winding group, insulating varnish is injected into the core slot to fill the gaps within the slot and prevent the wires from moving within the slot, so that the magnet wires do not wear out and the insulation does not deteriorate. However, since the varnish on the stator edge has the characteristic of expanding in volume when it hardens, when the insulating varnish hardens in the gap, the wires are displaced or deformed, and the hairpin wires close to the inner diameter of the core sometimes protrude from the slot opening. Under such circumstances, when the core is inserted into the rotor and operated, the rotor easily comes into contact with the wires, damaging the stator and increasing the product defect rate.
[0007] Therefore, the inventor believed that the above-mentioned shortcomings could be improved, and after extensive research, he came up with the present invention, which effectively improves the above-mentioned problems through rational design.
[0008] The present invention was made in consideration of the above problems and through extensive research by the inventor, and its object is to provide a stator structure for a group of rectangular wire windings. [Means for solving the problem]
[0009] In order to solve the above problems, the stator structure of the flat wire winding group of one embodiment of the present invention includes a stator core, a flat wire winding group, and an insulating sheet. The stator core includes an annular yoke portion and a plurality of teeth arranged along the circumferential direction of the yoke portion, and a slot extending along the radial direction is formed between adjacent pairs of the teeth, and a boot portion extending along the circumferential direction is provided at the end of the pair of the teeth, and a slot opening of the slot is formed. The flat wire winding group includes a plurality of linear conductors, and the linear conductors have extensions positioned in the slots. An insulating sheet covers the extensions arranged in order, and the insulating sheet is attached to the slots and is located between the extensions and the surface of the slots.
[0010] A mating inner block is provided within the slot, the protruding direction of the inner block is perpendicular to the radial direction, and the expanded portion is limited between the inner block and the slot bottom of the slot.
[0011] In a direction perpendicular to the radial direction, the width of the slot is Sw, the width of the opening of the slot is G1, the extension portion has a width Lw, the thickness of the insulating sheet is It, and the separation distance between a pair of the inner blocks is G2, satisfying the following condition: G1 ≦ G2 < Lw, and It + 0.2 mm < 0.5 × (Sw-G2) ≦ It + 1 mm
[0012] In the above-described structure, a pair of inner blocks positioned within the slot confine multiple linear conductors (flat copper wires) within the slot, so that when the flat copper wires are compressed and deformed by an external force, the deformation of the copper wires is restricted between the inner blocks and the bottom of the slot, thereby improving manufacturing yield.
[0013] Preferably, the following conditions are further satisfied: 0.1 mm ≦ It ≦ 0.3 mm
[0014] Preferably, the insulating sheet has a main portion and two folded portions extending outward from both sides spaced from the main portion, and the insulating sheet is curved so that the two folded portions overlap and cover the arranged multiple extended portions, and the two folded portions of the insulating sheet are directed toward the bottom of the slot.
[0015] Preferably, the inner block has a tip and two inclined surfaces extending from both sides away from the tip, and the slot has two slot walls extending from both sides away from the slot bottom. In a cross section, a first point and a second point are defined by the extension lines of the two inclined surfaces intersecting with the extension lines of the adjacent slot walls, the second point is located between the first point and the boot portion, and a third point is defined by the extension lines of the slot walls intersecting with a boundary of the inner peripheral surface of the stator core. In the cross-section, the extension portion has a thickness Lt and is parallel to the extension line of the slot wall, the distance from the first point to the second point is L3, and the distance from the second point to the third point is L4, and the following condition is satisfied: Lt ≦ L3+L4 This causes the copper wire to deform within the slot and protrude through the slot opening.
[0016] Preferably, the following conditions are further satisfied: Lt ≦ L4
[0017] At least the following points will become apparent from the following specification and drawings. [Brief description of the drawings]
[0018] [Figure 1] 1 is a schematic development view showing a stator structure according to an embodiment of the present invention; [Diagram 2] 1 is a cross-sectional view showing a stator structure according to an embodiment of the present invention; [Diagram 3] FIG. 3 is a partially enlarged view of FIG. [Figure 4] FIG. 2 is a schematic diagram showing a stator slot according to an embodiment of the present invention. [Diagram 5] FIG. 3 is a partially enlarged view of FIG. [Figure 6A] 11A and 11B are magnetic field distribution diagrams showing examples of stator slots with different structures. [Figure 6B] 11A and 11B are magnetic field distribution diagrams showing examples of stator slots with different structures. [Figure 6C] 11A and 11B are magnetic field distribution diagrams showing examples of stator slots with different structures. [Figure 6D] 11A and 11B are magnetic field distribution diagrams showing examples of stator slots with different structures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] The following describes in detail the embodiments of the present invention, but the present invention is not limited to these, and various modifications are possible within the scope of the description, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present invention.
[0020] The motor structure according to the present invention includes an inner rotor and an outer stator, and the complete stator structure is an annular structure. In order to clearly distinguish each structure, only a part of the stator structure is shown in this embodiment. Figures 1 and 2 show a part of the stator structure, which includes a stator core 10, an insulating sheet 20, and a rectangular wire winding group 30.
[0021] The stator core 10 is a plurality of core units 101 formed by stacking them in the axial direction, and each core unit 101 has an annular yoke portion 11 and a plurality of teeth 12 arranged in the circumferential direction of the yoke portion 11. A slot 15 extending in the radial direction is formed between a pair of adjacent teeth 12, and a boot portion 121 extending in the circumferential direction is provided at the end of the pair of teeth 12. The tip portions 121t of the pair of boot portions 121 are symmetrical in the radial direction and have a slot opening 151 of the slot 15. The slot 15 has a slot bottom 153 adjacent to the yoke portion 11 and two slot walls 152 extending from both sides spaced apart from the slot bottom 153. A surface of a portion of the boot portion 121 faces the inner rotor, and the surface of the portion is the inner peripheral surface 51 of the core unit 101, and the outer peripheral surface 52 of the core unit 101 is spaced apart from the teeth 12.
[0022] The rectangular wire winding group 30 includes a plurality of linear conductors 31, and the linear conductors 31 may have the same or different shapes. In the following, an example will be described in which hairpin windings are used as the linear conductors 31. The linear conductor 31 has one curved portion (not shown) and two extended portions 31A extending from both ends spaced apart from the curved portion, and a connection portion 31B is formed at the end of each of the two extended portions 31A.
[0023] When installing the linear conductor 31, the linear conductor 31 is first folded into a U-shape (forming an extended portion 31A and a curved portion), and the two extended portions 31A are inserted into different slots 15 along the axial direction, so that the curved portions of all the linear conductors 31 are located on the end faces of the stator core 10, and the extended portions 31A of the linear conductors 31 are all located on the other end faces of the stator core 10. The ends of all the extended portions 31A are subjected to a process of twisting and cutting flat, and then the wires at the ends of the extended portions 31A are exposed to form the connecting portions 31B. The two corresponding connecting portions 31B are welded based on the wiring to form a complete circuit.
[0024] In this embodiment, the portion of the linear conductor 31 located within the slot 15 is defined as the extended portion 31A, and during the installation process, the extended portion 31A is deformed by an external force, which increases the defect rate. In addition, the shape of the linear conductor 31 is not U-shaped, but is, for example, an I-shaped pin, an S-shaped winding (continuous hairpin), or an X-shaped pin defined in the prior art. All of the above conductors have the extended portion 31A located within the slot 15, and all fall within the scope of the linear conductor 31 defined in this embodiment.
[0025] The insulating sheet 20 is attached to the slot 15 and is located between the extension portions 31A and the inner surface of the slot 15 (slot wall 152, slot bottom 153). The insulating sheet 20 is configured to cover the multiple extension portions 31A arranged in the slot 15, and ensures insulation between the linear conductors 31 and the slot 15.
[0026] 2, 4, and 5 show the contour formed by the cross section of the slot 1 of the stator core 10 perpendicular to the axial direction of the stator core 10. A pair of inner blocks 14a, 14b are formed to protrude from the inner surface of the slot 15, and the protruding direction of the inner blocks 14a, 14b is perpendicular to the slot extension direction Db. When the flat wire winding group 30 is attached, the extension portion 31A is limited between the inner blocks 14a, 14b and the slot bottom 153.
[0027] The width direction Da of the slot 15 is perpendicular to the radial direction of the stator core 10, and in the width direction Da, the width of the slot 15 is Sw, the width of the opening of the slot 15 is G1, the extension portion 31A has a width Lw, the thickness of the insulating sheet 20 is It, and the separation distance between the pair of inner blocks 14a, 14b is G2, satisfying the following condition. G1 ≦ G2 < Lw, and It + 0.2 mm < 0.5 × (Sw-G2) ≦ It + 1 mm.
[0028] 0.5 × (Sw-G2) is the protruding distance Bd of one inner block 14a (or inner block 14b) toward the inside of the slot 15 with respect to the slot wall 152, and the inner blocks 14a, 14b located on the slot walls 152 on different sides are installed symmetrically. Under this condition, the protruding distance Bd of the inner block 14a toward the inside of the slot 15 is about 0.3 to about 1 time the protruding distance of the boot portion 121 toward the slot 15.
[0029] The pair of inner blocks 14a, 14b confine the linear conductors within the slot, and when the extension portion 31A is compressed and deformed by an external force, the deformation of the extension portion 31A is limited between the inner blocks and the bottom of the slot. By filling the insulating paint in the insulating paint filling area 60 in the slot 15 and allowing it to harden, it is possible to increase the manufacturing yield while preventing excessive deformation.
[0030] In addition, the following conditions must be met: 0.1 mm ≦ It ≦ 0.3 mm
[0031] In addition, the following conditions must be met: It + 0.2 mm < Bd ≦ It + 0.6 mm Under this condition, the protruding distance Bd of the inner block 14 a toward the inside of the slot 15 is about 0.4 to about 0.6 times the protruding distance of the boot portion 121 toward the slot 15 .
[0032] In this embodiment, the width Sw of the slot 15 satisfies the following condition. 3 mm ≦ Sw ≦ 5 mm The width Lw of the extension portion 31A satisfies the following condition. 2.5 mm ≦ Lw ≦ 4.5 mm
[0033] Considering the punching process of the stator core 10 at the same time, in the cross section shown in FIG. 4, the inner block 14a has a tip 14t and two inclined surfaces 14s1, 14s2 extending from both sides away from the tip 14t, the tips of the two inner blocks 14a, 14b are aligned with each other, and the distance therebetween is defined as a separation distance G2.
[0034] In this embodiment, the center lines of the slots 15 overlap in the radial direction of the stator core 10, and a slot extension direction Db of the slots 15 is defined. In the cross section, the two slot walls 152 are all parallel to the slot extension direction Db, and the extension lines of the two inclined surfaces 14s1 and 14s2 of each inner block 14a intersect with the extension lines of the adjacent slot walls 152 to define a first point 14p1 and a second point 14p2. The second point 14p2 is located between the first point 14p1 and the boot portion 121. The extension line of the slot wall 152 intersects with the boundary of the inner circumferential surface 51 of the stator core 10 to define a third point 51p3.
[0035] In the cross section, the extension portion 31A has a thickness Lt and is parallel to the slot extension direction Db. The distance from the slot bottom to the third point 51p3 is L1, the distance from the slot bottom 153 to the first point 14p1 is L2, the distance from the first point 14p1 to the second point 14p2 is L3, and the distance from the second point 14p2 to the third point 51p3 is L4. That is, L1, L2, L3, and L4 satisfy the following relational expressions. L1 = L2 + L3 + L4 Based on the objective of this embodiment, the following conditions are met. Lt ≦ L3+L4 That is, the inner blocks 14a and 14b limit the distance of the extension portion 31A in the slot 15 to the thickness Lt of one extension portion 31A of the slot opening 151. In this way, even if the copper wire is deformed in the slot, it will not protrude from the slot opening.
[0036] In addition, the following conditions must be met: Lt ≦ L4
[0037] In this embodiment, the thickness Lt of the extension portion 31A satisfies the following condition. 1.5 mm ≦ Lt ≦ 3 mm
[0038] In this embodiment, a flat portion 13 is formed at the joint between the boot portion 121 and the inner block 14a (or the inner block 14b), and in the cross section, the flat portion 13 overlaps with the extension line of the slot wall 152.
[0039] In this case, as shown in Fig. 2 and Fig. 3, in this embodiment, the insulating sheet 20 has a main portion 21 and two folded portions 22A extending outward from both sides spaced apart from the main portion 21. When the insulating sheet 20 is placed inside the slot 15, the insulating sheet 20 is curved to overlap the two folded portions 22A, 22B and cover the arranged multiple extended portions 31A. In this embodiment, the two overlapping folded portions 22A, 22B of the insulating sheet 20 are directed toward the slot bottom 153 and cover the extended portion 31A approaching the outer peripheral surface 52. The main portion 21 of the insulating sheet 20 is curved in the gap between the pair of inner blocks 14a, 14b and covers the extended portion 31A approaching the inner peripheral surface 51.
[0040] When the stator structure is installed, the folded parts 22A, 22B of the insulating sheet 20 are only overlapped and not bonded. When the folded parts 22A, 22B are directed toward the hollow part in the slot 15, they are compressed by the multiple extension parts 31A coated on the insulating sheet 20, or expand when the insulating paint hardens, causing the folded parts 22A, 22B to unfold. In this way, the folded parts 22A, 22B are directed toward the slot bottom 153, and the main part 21 of the insulating sheet 20 is locked between the extension parts 31A and the inner blocks 14a, 14b, preventing the above-mentioned situation. In addition, the installation method of the insulating sheet 20 is compatible with the inner blocks 14a, 14b, and can ensure the degree of deformation of the extension parts 31A.
[0041] In one specific embodiment, eight extensions 31A are disposed within the slot 15. G1 is 1.6 mm, G2 is 2.74 mm, Lw is 3.51 mm, Sw is 4.3 mm, It is 0.25 mm, Bd is 0.78 mm, Lt is 1.8 mm, L2 is 16.27 mm, L3 is 0.91 mm, and L4 is 1.85 mm.
[0042] In another specific embodiment, six extensions 31A are disposed within the slot 15. G1 is 1.6 mm, G2 is 3.1 mm, Lw is 3.43 mm, Sw is 4.5 mm, It is 0.2 mm, Bd is 0.7 mm, Lt is 2.38 mm, L2 is 16.78 mm, L3 is 0.92 mm, and L4 is 1.8 mm.
[0043] 6A, 6B, 6C, and 6D are magnetic field distribution diagrams simulating the operation of the stator and rotor 70, and the position of the stator is indicated by the stator core 10. The stator core 10 of FIG. 6A does not have an inner block. The stator core 10 of FIG. 6B has an inner block, and the protruding distance of the inner block facing the inside of the slot is about 0.5 times the protruding distance of the boot part facing the slot. The stator core 10 of FIG. 6C has an inner block, and the protruding distance of the inner block facing the inside of the slot is about 1 time the protruding distance of the boot part facing the slot. The tips of the two inner blocks of the stator core 10 of FIG. 6C are connected, that is, G2=0.
[0044] As described above, in this embodiment, the stator core 10 has an inner block, and the inner block does not affect the existing operation of the motor structure within the above-mentioned range, and has the effect of improving the process yield.
[0045] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]
[0046] 10 Stator core 101 Core unit 11 York 12 Teeth 121 Boots 121t tip 13 Flat area 14a Inner Block 14b Inner Block 14t tip 14p1 1st point 14p2 2nd point 14s1 Slope 14s2 Slope 15 Slots 151 Slot opening 152 Slot Wall 153 Slot bottom 20 Insulation sheet 21 Main Parts 22A Folding part 22B Folding part 30 Flat wire winding group 31 Linear conductor 31A Extension 31B Connection part 51 Inner surface 52 Outer surface 51p3 3rd point 60 Insulation paint filling area 70 Rotor 71 Permanent Magnets G1 opening width G2 separation distance L1 Length L2 Length L3 Length L4 Length Da Width direction Db Slot extension direction It Insulation paper thickness Lw Wire width Lt Wire thickness Sw Slot width Bd protrusion distance
Claims
1. a stator core including an annular yoke portion and a plurality of teeth arranged along a circumferential direction of the yoke portion, a slot extending along a radial direction is formed between each pair of adjacent teeth, a boot portion extending along a circumferential direction is provided at an end of each pair of teeth, and a slot opening of the slot is formed; a rectangular wire winding group including a plurality of linear conductors, each of the linear conductors having an extension portion positioned in the slot; An insulating sheet covering the arranged extension parts, the insulating sheet being attached to the slot and positioned between the extension parts and a surface of the slot, The slot has a mating inner block, and the protruding direction of the inner block is perpendicular to the radial direction, and the expansion portion is limited between the inner block and the slot bottom of the slot, A stator structure of a flat wire winding group, characterized in that, in a direction perpendicular to the radial direction, the width of the slot is Sw, the width of the opening of the slot is G1, the extension portion has a width Lw, the thickness of the insulating sheet is It, and a separation distance between a pair of the inner blocks is G2, and the following conditions are satisfied: G1 ≦ G2 < Lw, and It + 0.2 mm < 0.5 × (Sw-G2) ≦ It + 1 mm.
2. 2. A stator structure for a rectangular wire winding group according to claim 1, characterized in that the following conditions are satisfied: 0.1 mm ≦ It ≦ 0.3 mm
3. 2. A stator structure for a rectangular wire winding group according to claim 1, characterized in that the following conditions are satisfied: It + 0.2 mm < 0.5 × (Sw-G2) ≦ It + 0.6 mm
4. 2. The stator structure with rectangular wire windings according to claim 1, wherein a flat portion is formed at a joint between the boot portion and the inner block.
5. The stator structure of the flat wire winding group according to claim 1, characterized in that the insulating sheet has a main portion and two folded portions extending outward from both sides spaced from the main portion, the insulating sheet is curved so that the two folded portions overlap and cover the arranged extended portions, and the two folded portions of the insulating sheet are directed toward the bottom of the slot.
6. the inner block has a tip and two inclined surfaces extending from opposite sides away from the tip, the slot has two slot walls extending from opposite sides away from the slot bottom, In a cross section, a first point and a second point are defined by intersecting an extension line of the adjacent slot wall of each of the two inclined surfaces, the second point is located between the first point and the boot portion, and a third point is defined by intersecting the extension line of the slot wall with a boundary of an inner peripheral surface of the stator core, 2. The stator structure of the flat wire winding group according to claim 1, characterized in that, in the cross section, the extension portion has a thickness Lt and is parallel to the extension line of the slot wall, the distance from the first point to the second point is L3, and the distance from the second point to the third point is L4, and the following condition is satisfied: Lt≦L3+L4
7. 7. A stator structure for a rectangular wire winding group according to claim 6, characterized in that the following conditions are satisfied: Lt≦L4
8. 2. The stator structure of claim 1, wherein an insulating paint is filled between the insulating sheet and the extended portion.