Stator assembly and motor

Abstract

The invention relates to a stator assembly, a motor and an electric driving system, the stator assembly comprises a stator iron core and a stator winding, the stator iron core is provided with a plurality of stator teeth and stator tooth grooves formed among the stator teeth, the number of the stator tooth grooves is 48, and conductor elements are arranged in 8 layers in each tooth groove, each phase of winding is provided with four parallel branches, the winding modes between the phases of windings are the same, the wire inlet ends between the V phase and the U phase are spaced by four tooth grooves, the wire inlet ends between the W phase and the V phase are spaced by four tooth grooves, the wire inlet ends of two branches are located on the outermost layer in the radial direction, and the wire inlet ends of the other two branches are located on the innermost layer in the radial direction. A winding design mode suitable for a 48-slot 8-layer stator is provided on the design basis of four-way parallel connection, in-phase circulation is avoided, design and manufacturing of a busbar are facilitated, meanwhile, the specification number of conductor elements is small, the complexity of the manufacturing process is reduced, and the manufacturing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a stator assembly and a motor. Background Art

[0002] Traditional motors use round conductors to form windings, where the conductors are wound around the stator teeth according to a certain pattern. For round conductors, since their cross-section is round, when multiple turns of conductor are wound around a stator tooth, there must be gaps between the conductor elements in the stator tooth slots, which results in a low slot fill rate. The motor thermal load is negatively correlated to the slot fill rate, so traditional round wire windings are not conducive to further improving the power density of the motor.

[0003] At present, a scheme has been proposed to form motor windings using conductors with rectangular cross sections. As the name implies, this winding is also called flat wire winding because the cross section of the conductor is rectangular, and the motor using flat wire winding is also called flat wire motor. Since the cross section of the winding is rectangular, when multiple conductor elements are placed in the stator slots, they can be arranged more closely to each other, and the slot fill rate is improved compared to round wire motors.

[0004] Unlike windings using round conductors, flat wire windings are not formed by winding a continuous conductor around the stator teeth. Instead, multiple single conductor elements are arranged in a predetermined order in the tooth slots, and then the individual conductor elements are welded according to a predetermined winding method to form a circuit connection.

[0005] Therefore, for flat wire motors, the position and connection relationship of each conductor element forming the winding is an important research content, which directly affects the electrical performance of the motor, the specifications and quantity of the conductor elements, the manufacturing process, the manufacturing process of the busbar connected to the winding, etc. Taking Chinese patent application CN114465390A as an example, it discloses a flat wire motor winding, which adopts a single branch or two branches. In particular, from the application Figure 7 It can be seen that the lead-out terminal has 36 pins, which are located at opposite ends in the radial direction. This design makes the design of the busbar connected to the pins more complicated, and because it uses a single branch or two branches, although it is easy to eliminate the circulating current and the winding process is relatively simple, the number of series turns per phase is high, the heat load is large, and the power drops rapidly at high speed.

[0006] Therefore, as the application of flat wire motors in automobiles becomes more and more widespread, in order to make flat wire motors better adapt to the use needs of new energy vehicles, it is necessary to provide flat wire motors with higher performance and lower manufacturing costs. Summary of the invention

[0007] In view of this, the present invention proposes the following technical solution.

[0008] A stator assembly comprises a stator core and a stator winding, wherein the stator core has a plurality of stator teeth and stator slots formed between the stator teeth, wherein the stator slots accommodate a portion of the stator winding, wherein the stator winding is made of a plurality of conductor elements with rectangular cross-sections, wherein the number of the stator slots is 48 and the conductor elements are arranged in 8 layers in each slot, wherein the stator winding comprises a U-phase winding, a V-phase winding and a W-phase winding, wherein each phase winding has four parallel branches, and the winding methods of each phase winding are the same, wherein the inlet end between the V-phase and the U-phase is spaced apart by four slots, and the inlet end between the W-phase and the V-phase is spaced apart by four slots, and for each phase winding, the inlet ends of two branches are located in the radially outermost layer, and the inlet ends of the other two branches are located in the radially innermost layer.

[0009] According to one aspect of the present invention, each of the four parallel branches of each phase winding has four periods, and the span variation mode in each period is the same.

[0010] According to one aspect of the present invention, for the first branch and the third branch of the four branches of each phase winding, the span variation pattern is 6-7-6-5-6-7-6 in each cycle.

[0011] According to one aspect of the present invention, for the first branch and the third branch of the four branches of each phase winding, the spans between two cycles connected to each other are 5, 4, and 5 respectively.

[0012] According to one aspect of the present invention, for the second branch and the fourth branch of the four branches of each phase winding, the span variation pattern is 6-5-6-7-6-5-6 in each cycle.

[0013] According to one aspect of the present invention, for the second branch and the fourth branch of the four branches of each phase winding, the spans between two cycles connected to each other are 7, 6, and 7 respectively.

[0014] According to one aspect of the present invention, for the first branch and the second branch of each phase winding, in each cycle, the number of layers changes alternately between 2n-1 and 2n, where n is the sequence number of the cycle.

[0015] According to one aspect of the present invention, for the third branch and the fourth branch of each phase winding, the number of layers thereof is alternately changed between 10-2n and 9-2n for four periods of each branch.

[0016] The present invention also provides a motor, comprising a rotor assembly and a stator assembly, wherein the stator assembly adopts the above-mentioned stator assembly.

[0017] The present invention also proposes an electric drive system, comprising at least one of a reducer and an inverter, and the above-mentioned motor.

[0018] As can be seen from the above, the present invention proposes a stator winding with 48 slots and 8 layers, which has the following advantages:

[0019] (1) A winding design method suitable for a 48-slot 8-layer stator is proposed based on four-way parallel connection, which avoids the disadvantages of high number of series turns per phase, large heat load, and rapid power drop at high speed caused by one branch or two branches in parallel connection;

[0020] (2) By arranging and designing the windings with four pairs of poles per phase, the potential is balanced to avoid intra-phase circulating currents;

[0021] (3) By rationally designing the connection method of each phase winding, the lead wires are kept close to each other, which facilitates the design and manufacture of the busbar. At the same time, the number of specifications of the conductor components is reduced, which reduces the complexity of the manufacturing process and improves manufacturing efficiency.

[0022] Other features and advantages of the present invention will be described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, in which:

[0024] Figure 1 A perspective view of a motor according to an embodiment of the present invention is shown.

[0025] Figure 2 A perspective view of a stator assembly according to an embodiment of the present invention is shown.

[0026] Figure 3 A perspective view of a branch of a phase winding in a stator assembly according to an embodiment of the present invention is shown.

[0027] Figure 4 A perspective view of four branches of a phase winding in a stator assembly according to an embodiment of the present invention is shown.

[0028] Figure 5 The expanded design diagram of the stator winding of the present invention is shown.

[0029] Figure 6 The U-phase development design diagram of the stator winding of the present invention is shown.

[0030] Figure 7 The V-phase development design diagram of the stator winding of the present invention is shown.

[0031] Figure 8 The W-phase development design diagram of the stator winding of the present invention is shown.

[0032] Fig. 9 The nomenclature of the tooth grooves and layer numbers is shown schematically.

[0033] All the drawings are only schematic and not necessarily drawn to scale, and they only show those parts necessary for explaining the present invention, and other parts are omitted or only mentioned. That is, in addition to the parts shown in the drawings, the present invention may also include other parts.

[0034] In the figures, identical and / or functionally identical technical features are provided with identical or similar reference numerals. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that the present invention may be implemented without some of these specific details. In addition, it should be understood that the present invention is not limited to the specific embodiments described. On the contrary, any combination of the features and elements described below may be considered to implement the present invention, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are intended for illustration purposes only and should not be considered as features or limitations of the claims unless explicitly stated in the claims.

[0036] In the following description, the descriptions about directions, such as "upper", "lower", "inner", "outer", "radial", "axial", etc., which may be used, are only for the convenience of description, unless otherwise specified, and are not intended to form any limitation on the technical solution of the invention. In addition, in the following description, terms such as "first", "second", etc. are used to describe the elements of the present application, and these terms are only used to distinguish the elements, and are not intended to limit the nature, sequence, order or number of these elements.

[0037] Figure 1 shows a three-dimensional view of a motor according to an embodiment of the present invention, Figure 2 FIG. 2 shows a perspective view of a stator assembly according to an embodiment of the present invention. Figure 1 As can be seen in the figure, the motor M has a stator assembly, and the stator assembly has a stator core 10, a stator winding 20 and a busbar assembly 30. A rotor assembly (not shown) may be arranged in the radially inner cavity of the stator assembly, and a motor housing (not shown) may be arranged in the radially outer cavity of the stator assembly. Figure 2 It can be seen that the stator core 10 has a cylindrical body 11, thereby defining an axis, and a plurality of evenly arranged stator teeth are arranged radially inside the body 11, thereby correspondingly forming a plurality of tooth slots between the plurality of stator teeth. In the present invention, the number of tooth slots is 48.

[0038] The stator winding 20 is composed of a plurality of conductor elements, and the conductor elements include a first element that is U-shaped in an initial state and a second element that is I-shaped in an initial state. When manufacturing the stator winding, the two legs of the same first element are respectively placed in two different stator tooth slots, and the portion of the leg extending outside the body 11 is bent and welded with other conductor elements according to a predetermined connection relationship. For the stator winding 20, for each first element, the portion connecting the two legs is located at the first end 21 of the body 11, and the bent portion is located at the second end 22 of the body 11. In other words, the first elements are all inserted into the tooth slots along the same direction. In each tooth slot, 8 layers of conductors are arranged in sequence. For the convenience of description, the layers are referred to as the 1st layer to the 8th layer in radial order from the outside to the inside.

[0039] In order to supply current to the stator winding 20, a lead wire 23 is provided. Figure 2 As can be seen from the figure, the lead wire 23 is formed by the second element and is located at the first end 21. Thus, the busbar assembly 30 is disposed at the first end 21. Figure 2 It can be seen from the figure that the lead wires 23 of the stator winding of the present invention are all located within a semicircle. More preferably, all the lead wires 23 are located within a sector with a central angle less than 142.5°. This design allows the lead wires to be closer together, thus facilitating the design of the busbar. Figure 1 It can be seen that this design makes the manufacturing process of the busbar simpler and the size of the busbar is smaller, which is conducive to the compact design of the motor.

[0040] In the present invention, the stator winding is a three-phase winding, namely, a U phase, a V phase and a W phase, and each phase winding adopts a four-way parallel connection mode. Figure 3 FIG. 1 shows a three-dimensional view of a branch of a phase winding in a stator assembly according to an embodiment of the present invention. Figure 4 A three-dimensional view of four branches of a phase winding in a stator assembly according to an embodiment of the present invention is shown. As mentioned above, when designing a circuit, although a single branch or two branches can easily eliminate circulating current and the winding process is relatively simple, the number of series turns per phase is high, the heat load is large, and the power drops rapidly at high speeds. To this end, the present invention proposes a single-phase four-way parallel design method, which overcomes the above-mentioned shortcomings, and by arranging and designing the winding arrangement of 4 pairs of poles per phase, the potential is balanced and the intra-phase circulating current is avoided.

[0041] Figure 5 The expanded design diagram of the stator winding of the present invention is shown. Figure 6 The U-phase development design diagram of the stator winding of the present invention is shown. Figure 7 The V-phase development design diagram of the stator winding of the present invention is shown. Figure 8The W-phase development design diagram of the stator winding of the present invention is shown. Figures 5 to 8 The winding design of the present invention is described in detail.

[0042] Taking the U-phase winding method as an example, the stator slots where the conductor elements of the four parallel branches U1, U2, U3 and U4 are located and the number of layers in the stator slots are described as follows, where the numbers outside the brackets represent the serial numbers of the stator slots, and the numbers inside the brackets represent the number of layers. Fig. 9 The nomenclature of the tooth grooves and layer numbers is shown schematically.

[0043] For U1, it has an input terminal U1_in and an output terminal U1_out. In the U1 branch, the position and connection relationship of the conductor elements in the tooth slot are: U1_in→1(1)→43(2)→36(1)→30(2)→25(1)→19(2)→12(1)→6(2)——1(3)→43(4)→36(3)→30(4)→25(3)→19(4)→12(3)→6(4)——2(5)→44(6)→37(5)→31(6)→26(5)→20(6)→13(5)→7(6)——2(7)→44(8)→37(7)→31(8)→26(7)→20(8)→13(7)→7(8)→U1_out.

[0044] Combination Figure 6 In the above winding method, starting from the connection terminal, each 8 effective sides of the branch are defined as a winding cycle, and the winding of the stator winding enters the next winding cycle after the end of a winding cycle, and the winding is output after a total of 4 winding cycles. In the above text, "——" is used to show the boundaries between each winding cycle.

[0045] According to the above winding connection method, the winding connection method of the first branch U1 has the following characteristics:

[0046] (1) In each cycle, the number of layers changes alternately between 2n-1 and 2n, where n is the sequence number of the cycle. For example, in the first cycle, since n=1, the number of layers is 1-2-1-2-1-2-1-2. Similarly, in the second cycle, since n=2, the number of layers is 3-4-3-4-3-4-3-4. The same is true for the third and fourth cycles.

[0047] (2) The span variation pattern in each cycle is the same. Specifically, in each cycle, the span variation pattern is 6-7-6-5-6-7-6.

[0048] (3) In the 7 spans in each cycle, the 1st, 3rd, 5th and 7th spans are the same, specifically 6, the 2nd and 6th spans are the same, specifically 7, and the 4th span is 5. In this way, the conductor parts at the welding end are bent by 3 teeth respectively, so that the two adjacent conductor parts are bent by 6 teeth together, which greatly simplifies the bending process.

[0049] (4) Between two connected periods, the spans are 5, 4, and 5. Combining (3) and (4), it can be seen that since the span is 6 in the most common case and other spans are less common, the twisting process of the part connecting the two legs of the first element is relatively uniform, which also reduces the complexity of the manufacturing process and improves the manufacturing efficiency.

[0050] For the second branch U2, the winding method is as follows:

[0051] U2_in→48(1)→42(2)→37(1)→31(2)→24(1)→18(2)→13(1)→7(2)——48(3)→42(4)→37(3)→31(4)→24(3)→18(4)→13(3)→7(4)——1(5)→43(6)→38(5)→32(6)→25

[0052] (5)→19(6)→14(5)→8(6)——1(7)→43(8)→38(7)→32(8)→25(7)→19(8)→14(7)→8(8)→U2_out.

[0053] According to the above winding connection method, the winding connection method of the second branch U2 has the following characteristics:

[0054] (1) In each cycle, the number of layers changes alternately between 2n-1 and 2n, where n is the sequence number of the cycle. For example, in the first cycle, since n=1, the number of layers is 1-2-1-2-1-2-1-2. Similarly, in the second cycle, since n=2, the number of layers is 3-4-3-4-3-4-3-4. The same is true for the third and fourth cycles.

[0055] (2) The span variation pattern in each cycle is the same. Specifically, in each cycle, the span variation pattern is 6-5-6-7-6-5-6.

[0056] (3) In the 7 spans in each cycle, the 1st, 3rd, 5th and 7th spans are the same, specifically 6, the 2nd and 6th spans are the same, specifically 5, and the 4th span is 7. In this way, the conductor parts at the welding end are bent by 3 teeth respectively, so that the two adjacent conductor parts are bent by 6 teeth together, which greatly simplifies the bending process.

[0057] (4) Between two cycles connected to each other, the spans are 7, 6, and 7, respectively. Combined with (3), it can be seen that in the entire branch, there are only three span modes, namely 5, 6, and 7, which reduces the number of specifications of conductor components. Since the span of 6 is the most common, and other spans are less common, for the first component, the twisting process of the part connecting the two legs is also relatively uniform, which also reduces the complexity of the manufacturing process and improves the manufacturing efficiency.

[0058] For the third branch U3, its winding method is:

[0059] U3_in→1(8)→7(7)→14(8)→20(7)→25(8)→31(7)→38(8)→44(7)——1(6)→7(5)→14(6)→20(5)→25(6)→31

[0060] (5)→38(6)→44(5)——48(4)→6(3)→13(4)→19(3)→24(4)→30(3)→37(4)→43(3)——48(2)→6(1)→13(2)→19(1)→24(2)→30(1)→37(2)→43(1)→U3_out.

[0061] The third branch U3 enters from the inner side of the core, so the starting layer number is 8, and the winding direction is opposite to U1 and U2. In addition, the third branch U3 has many similarities with the first branch U1, especially the span mode is exactly the same.

[0062] For the fourth branch U4, its winding method is:

[0063] U4_in→2(8)→8(7)→13(8)→19(7)→26(8)→32(7)→37(8)→43(7)——2(6)→8(5)→13(6)→19(5)→26(6)→32(5)→37(6)→43(5)—— 1(4)→7(3)→12(4)→18(3)→25(4)→31(3)→36(4)→42(3)——1(2)→7(1)→12(2)→18(1)→25(2)→31(1)→36(2)→42(1)→U4_out.

[0064] The fourth branch U4 enters from the inner side of the core, so the starting layer number is 8. In addition, the fourth branch U4 has many similarities with the second branch U2, especially the span mode is exactly the same.

[0065] Combining the winding designs of the four branches of the U phase, it can be found that the winding method proposed in the present invention forms a short-distance winding and forms a potential balance between the four pairs of poles in each phase, thereby avoiding intra-phase circulating current.

[0066] The stator winding of the present invention adopts a three-phase symmetrical winding, so the winding method of the V and W phases is consistent with that of the U phase, and only the number of the inlet and outlet slots is different. Figure 7 and Figure 8 It can be seen that the V-phase incoming line is 4 slots away from the U-phase, and the W-phase incoming line is 4 slots away from the V-phase.

[0067] From the above, it can be seen that in the stator winding of the present invention, a 4-way parallel winding method is adopted, which avoids the shortcomings of a high number of series turns per phase, a large heat load, and a rapid power drop at high speed that exist in one branch or two branches in parallel, and through the design of the arrangement of 4 pairs of poles per phase, the potential balance is achieved to avoid intra-phase circulation; through the reasonable design of the connection method of each phase winding, the lead wires are made close to each other, which is convenient for the design and manufacture of the bus, and at the same time, the number of specifications of the conductor components is reduced, reducing the complexity of the manufacturing process and improving the manufacturing efficiency.

[0068] The motor with the stator winding of the present application can be applied to various types of electric vehicles, for example, a pure electric vehicle powered only by a battery, or a hybrid vehicle equipped with other types of power sources in addition to the motor.

[0069] The present invention has been clearly and completely described with reference to the above exemplary embodiments, and it should be understood by those skilled in the art that various other embodiments can be conceived by modifying the disclosed technical solutions without departing from the spirit and scope of the present invention. These embodiments should be understood to fall within the scope of the present invention determined based on the claims and any equivalent technical solutions thereof.

Claims

1. A stator assembly, comprising a stator core and a stator winding, wherein the stator core has a plurality of stator teeth and stator slots formed between the stator teeth, wherein the stator slots accommodate a portion of the stator winding, wherein the stator winding is made of a plurality of conductor elements having a rectangular cross section, wherein the number of the stator slots is 48 and the conductor elements are arranged in 8 layers in each slot, wherein the stator winding comprises a U-phase winding, a V-phase winding and a W-phase winding, It is characterized in that Each phase winding has 4 parallel branches, and the winding methods of each phase winding are the same. The incoming line ends between the V phase and the U phase are separated by 4 tooth slots, and the incoming line ends between the W phase and the V phase are separated by 4 tooth slots. For each phase winding, the incoming line ends of two branches are located in the radial outermost layer, and the incoming line ends of the other two branches are located in the radial innermost layer.

2. The stator assembly according to claim 1, characterized in that Each of the four parallel branches of each phase winding has four periods, and the periods in each branch have the same span variation mode.

3. The stator assembly according to claim 2, characterized in that: For the first and third branches of the four branches of each phase winding, the span changes in each cycle in the manner of 6-7-6-5-6-7-6.

4. The stator assembly according to claim 3, characterized in that: For the first branch and the third branch of the four branches of each phase winding, the spans between two cycles connected to each other are 5, 4, and 5 respectively.

5. The stator assembly according to claim 2, characterized in that: For the second and fourth branches of the four branches of each phase winding, the span changes in each cycle in the manner of 6-5-6-7-6-5-6.

6. The stator assembly according to claim 5, characterized in that For the second and fourth branches of the four branches of each phase winding, the spans between two cycles connected to each other are 7, 6, and 7 respectively.

7. The stator assembly according to any one of claims 1 to 6, characterized in that: For the first branch and the second branch of each phase winding, in each cycle, the number of layers changes alternately between 2n-1 and 2n, where n is the sequence number of the cycle.

8. The stator assembly according to claim 7, characterized in that For the third branch and the fourth branch of each phase winding, for four periods of each branch, the number of layers changes alternately between 10-2n and 9-2n, where n is the serial number of the period.

9. An electric machine, comprising a rotor assembly and a stator assembly according to any one of claims 1 to 8.

10. An electric drive system, comprising at least one of a reducer and an inverter, characterized in that: Also included is the motor according to claim 9.

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