Mixed air gap type doubly salient motor

Abstract

The invention discloses a mixed air gap type doubly salient motor which comprises a stator, a rotor and a winding coil, the stator and the rotor are both of a salient pole structure, and the rotor is coaxially arranged in the middle of the stator; a mixed air gap is formed between the stator and the rotor, is rectangular and comprises an axial air gap and a radial air gap; the stator comprises stator poles and a stator yoke, the surface of each stator pole adopts a concave-convex structure, and the stator poles are the same in size and shape; the rotor comprises rotor poles and a rotor yoke, the surfaces of the rotor poles adopt concave-convex structures, the concave-convex structures of the rotor poles are matched with the concave-convex structures of the stator poles so as to form the mixed air gap, and the rotor poles are the same in size and shape. According to the invention, the overlapping area between the stator poles and the rotor poles of the motor at the aligned position is effectively enlarged, the air gap magnetic resistance is reduced, the air gap magnetic flux density of the motor is improved, and the output torque density and efficiency of the motor are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a hybrid air-gap double-salient-pole motor. Background Art

[0002] The stator and rotor of the double salient pole motor both adopt the salient pole structure, and the winding is placed on the stator. There is neither winding nor permanent magnet on the rotor. These structural characteristics make it simple, low cost, strong fault tolerance, good speed regulation performance and suitable for various harsh environments. Therefore, the double salient pole motor has broad application prospects in electric vehicles, general industry, household appliances, textiles, machinery, papermaking, coal mining, aerospace and other fields. However, the torque density and efficiency of traditional double salient pole motors are slightly lower than those of other types of motors, which limits its further application in various fields and becomes a bottleneck restricting its development.

[0003] In order to improve the output torque density and efficiency of the double-salient-pole motor, domestic and foreign scholars have comprehensively optimized the number of stator and rotor poles, winding arrangement, winding excitation method, and size parameters of the motor based on the traditional double-salient-pole motor structure. Although they can improve the performance of the double-salient-pole motor, its performance advantage is not obvious compared with other types of motors. In addition, the traditional double-salient-pole motor adopts a single air gap structure, which also makes it difficult to further improve its performance. Summary of the invention

[0004] The purpose of the present invention is to provide a hybrid air-gap double-salient pole motor, which can effectively expand the overlapping area between the stator poles and the rotor poles of the motor in the alignment position without changing the outer diameter, stack length, air gap length and stator and rotor pole arc coefficient of the motor, thereby reducing the air gap magnetic resistance, increasing the air gap magnetic flux density of the motor, and improving the output torque density and efficiency of the motor, thereby effectively solving the problems of low output torque density and low efficiency of traditional double-salient pole motors and expanding the application field of double-salient pole motors.

[0005] To achieve the above object, the present invention provides a hybrid air gap double salient pole motor, comprising a stator, a rotor and a winding coil, wherein the stator and the rotor are both salient pole structures, and the rotor is coaxially arranged in the middle of the stator; a hybrid air gap is formed between the stator and the rotor, and the hybrid air gap is rectangular in shape, and comprises an axial air gap and a radial air gap;

[0006] The stator comprises a stator pole and a stator yoke, wherein the stator pole is formed by extending the inner wall of the stator yoke inwardly along the radial direction, the stator poles are arranged on the inner wall of the stator yoke at equal intervals in the circumferential direction, the surface of the stator pole adopts a concave-convex structure, and the size and shape of each stator pole are the same;

[0007] The rotor includes a rotor pole and a rotor yoke. The rotor pole is formed by extending outward in the radial direction of the outer wall of the rotor yoke. The rotor poles are arranged on the outer wall of the rotor yoke at equal intervals in the circumferential direction. The surface of the rotor pole adopts a concave-convex structure, and the concave-convex structure matches the concave-convex structure of the stator pole to form the mixed air gap, and the size and shape of each rotor pole are the same.

[0008] Preferably, the number of stator poles N of the stator s and the number of rotor poles N of the rotor r The lowest common multiple is the number of motor phases m and the number of rotor poles N r The product of is expressed as:

[0009] LCM(N s ,N r )=mN r .

[0010] Preferably, the winding coil adopts concentrated winding, and the winding coil is wound on each stator pole with the same number of turns; the winding coil is divided into m phases according to the number of phases of the motor, and each phase winding is composed of the winding coils on the stator poles separated by m-1.

[0011] Preferably, the connection modes of the windings of each phase of the winding coils are completely the same and all adopt direct current power supply.

[0012] Preferably, the stator and the rotor are both made by laminating silicon steel sheets, and the length of the axial air gap in the mixed air gap is adjusted by using a combination of silicon steel sheets of a single thickness or different thicknesses.

[0013] Preferably, the stator adopts a modular structure and is assembled and formed by keyways provided in the stator yoke.

[0014] Beneficial effects of the present invention:

[0015] (1) By adopting a hybrid air gap structure, the overlapping area between the stator poles and the rotor poles of the motor in the aligned position is effectively expanded without changing the motor outer diameter, stack length, air gap length, and stator and rotor pole arc coefficient, thereby reducing the air gap magnetic resistance, increasing the air gap magnetic flux density of the motor, and improving the output torque density and efficiency of the motor, thereby effectively solving the problems of low output torque density and low efficiency of traditional double-pole motors and expanding the application field of double-pole motors.

[0016] (2) By using a single thickness or a combination of silicon steel sheets of different thicknesses to make the stator and rotor of the motor, the selection of the axial air gap size in the mixed air gap becomes more flexible and varied, breaking through the problem that the selection of the axial air gap length is limited by the size of the silicon steel sheet when the stator and rotor of the motor are made of a single thickness silicon steel sheet.

[0017] (3) Due to the hybrid air gap structure, the stator and rotor cannot be assembled in the traditional motor way. By adopting a modular stator structure, the stator and rotor assembly problem caused by the hybrid air gap is effectively solved.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a hybrid air-gap double-salient-pole motor of the present invention;

[0020] Figure 2 It is a schematic cross-sectional structure diagram of a hybrid air-gap double-salient-pole motor of the present invention;

[0021] Figure 3 It is a schematic diagram of the stator structure of a hybrid air-gap double-salient-pole motor of the present invention;

[0022] Figure 4 It is a schematic diagram of the rotor structure of a hybrid air-gap double-salient-pole motor of the present invention;

[0023] Figure 5 It is a cross-sectional schematic diagram of a local hybrid air gap structure of a hybrid air gap type double salient pole motor of the present invention;

[0024] Figure 6 It is a winding connection schematic diagram of a hybrid air-gap double-salient-pole motor of the present invention;

[0025] Figure 7 It is a schematic diagram of the magnetic flux path of the A-phase winding of a hybrid air-gap double-salient-pole motor after power is supplied to the winding;

[0026] Figure 8 This is a schematic diagram of silicon steel sheet lamination of a hybrid air-gap double-salient-pole motor solution 1 of the present invention;

[0027] Fig. 9 This is a schematic diagram of silicon steel sheet lamination of a second hybrid air-gap double-salient-pole motor according to the present invention;

[0028] Fig.10 This is a schematic diagram of silicon steel sheet lamination in a third scheme of a hybrid air-gap double-salient-pole motor of the present invention;

[0029] Fig.11 This is a schematic diagram of the stacking of silicon steel sheets of a fourth scheme of a hybrid air-gap double-salient-pole motor according to the present invention.

[0030] Reference numerals

[0031] 1. stator; 10. stator pole; 11. stator yoke; 2. winding coil; 3. rotor; 30. rotor pole; 31. rotor yoke; 4. keyway; 5. mixed air gap; 50. axial air gap; 51. radial air gap; 60. first silicon steel sheet; 61. second silicon steel sheet. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0033] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0034] A hybrid air-gap double-salient-pole motor provided by the present invention has a plurality of combinations of phase number m, stator pole number Ns and rotor pole number Nr, wherein the phase number m, stator pole number Ns and rotor pole number Nr include but are not limited to the following relationship: the least common multiple of the stator pole number Ns and the rotor pole number Nr is the product of the motor phase number m and the rotor pole number Nr, which can be expressed by the formula:

[0035] LCM(N s ,N r )=mN r

[0036] Therefore, any combination of phase number, stator pole number and rotor pole number that meets the above formula, such as three-phase 6 / 4 pole (motor phase number m is 3, stator pole number Ns is 6, rotor pole number Nr is 4), three-phase 12 / 8 pole (motor phase number m is 3, stator pole number Ns is 12, rotor pole number Nr is 8), four-phase 8 / 6 pole (motor phase number m is 4, stator pole number Ns is 8, rotor pole number Nr is 6), can be used as the phase number, stator pole number and rotor pole number of the double salient pole motor of the present invention. In summary, this embodiment is described in detail by taking a three-phase 6 / 4 pole double salient pole motor as an example.

[0037] Embodiment 1

[0038] like Figure 1 and Figure 2As shown, the present invention provides a hybrid air gap double salient pole motor, including a stator 1, a winding coil 2 and a rotor 3. The stator 1 and the rotor 3 are salient pole structures, and the rotor 3 is coaxially arranged in the middle of the stator 1. There is a hybrid air gap 5 between the stator 1 and the rotor 3. Due to the hybrid air gap 5, the assembly method of the traditional motor cannot be adopted between the stator 1 and the rotor 3, so the stator 1 adopts a modular structure and is assembled and formed by a keyway 4, which effectively solves the stator and rotor assembly problem caused by the hybrid air gap 5. .

[0039] like Figure 3 As shown, the stator 1 includes a stator pole 10 and a stator yoke 11. The stator pole 10 is formed by extending the inner wall of the stator yoke 11 inwardly along the radial direction. The stator poles 10 are arranged on the inner wall of the stator yoke 11 at equal intervals in the circumferential direction. The surface of the stator pole 10 adopts a concave-convex structure, and the size and shape of each stator pole 10 are the same. Figure 4 As shown, the rotor 3 includes a rotor pole 30 and a rotor yoke 31. The rotor pole 30 is formed by extending the outer wall of the rotor yoke 31 radially outward. The size and shape of each rotor pole 30 are the same. The rotor poles 30 are arranged on the outer wall of the rotor yoke 31 at equal intervals in the circumferential direction. The surface of the rotor pole 30 adopts a concave-convex structure, and its concave-convex structure matches the concave-convex structure of the stator pole 10 to form a mixed air gap 5, as shown in FIG. Figure 2 shown.

[0040] like Figure 5 As shown, the hybrid air gap 5 is in the shape of a rectangle, including an axial air gap 50 and a radial air gap 51. Without changing the outer diameter, stack length, air gap length, and stator and rotor pole arc coefficient of the motor, the hybrid air gap 5 can expand the overlapping area between the stator pole and the rotor pole of the motor in the aligned position, which can effectively reduce the air gap magnetic resistance, increase the air gap magnetic flux density of the motor, and thus improve the output torque density and efficiency of the motor, effectively solving the problems of low output torque density and low efficiency of traditional double-salient pole motors, and expanding the application field of double-salient pole motors.

[0041] like Figure 6 As shown, the winding coil 2 is a concentrated winding, which is wound on each stator pole 10, and the number of turns of the winding coil wound on each stator pole 10 is the same. Since the 6 / 4 pole motor is a three-phase motor, the winding coil 2 is divided into three phases, and the winding coils 2 on two stator poles are connected to form one phase. For example, the A phase winding consists of P s1 Stator pole and P s4 The windings on the stator poles are connected, and the B-phase winding is composed of P s2 Stator pole and P s5 The windings on the stator poles are connected, and the C phase winding is composed of P s3 Stator pole and P s6The windings on the stator poles are connected. At the same time, in order to ensure that the circuits and magnetic circuits of each phase of the motor are consistent, the connection methods of the three-phase windings A, B, and C must be exactly the same. Similarly, when the number of phases of the motor is m, the winding coil 2 will be divided into m phases, and the winding coils 2 on the m-1 stator poles are connected to form one phase, forming a total of m phases, and the connection methods of the m-phase windings are exactly the same. Among them, the winding coil 2 adopts a DC power supply method.

[0042] like Figure 7 As shown in the figure, when the A phase winding is energized, the magnetic flux Φ 0 Starting from the stator pole on one side where the A-phase winding is located, it passes through the air gap, passes through the rotor and the stator pole on the other side where the A-phase winding is located, and finally forms a closed loop through the stator yoke. According to the "minimum magnetic resistance principle", the magnetic flux Φ 0 The motor will generate electromagnetic torque, pushing the rotor 3 to the A-phase alignment position, that is, the position where the stator pole axis of the A-phase winding is aligned with the rotor pole axis. Similarly, when the B-phase winding is energized, a magnetic flux Φ 0 The motor generates electromagnetic torque, pushing the rotor 3 to move to the position aligned with phase B. When the C phase winding is energized, a magnetic flux Φ is generated in the motor. 0 The motor generates electromagnetic torque to push the rotor 3 to move to the position aligned with phase C. Therefore, when the three phases A, B, and C are turned on in turn, the motor can generate continuous reluctance torque to push the rotor to rotate.

[0043] The stator and rotor in this embodiment are made of laminated silicon steel sheets, and there are multiple lamination schemes:

[0044] Option 1: Figure 8 As shown, the stator 1 and the rotor 3 are both formed by laminating the first silicon steel sheets 60 , and the size of the axial air gap 50 is determined by the thickness of the first silicon steel sheets 60 .

[0045] Option 2: Fig. 9 As shown, the stator 1 and the rotor 3 are formed by laminating a first silicon steel sheet 60 and a second silicon steel sheet 61 . At this time, the size of the axial air gap 50 is determined by the thickness of the second silicon steel sheet 61 .

[0046] Option 3 Fig.10 As shown, the stator 1 is formed by laminating the first silicon steel sheets 60, and the rotor 3 is formed by laminating the second silicon steel sheets 61. At this time, the size of the axial air gap 50 is determined by the thickness of the first silicon steel sheets 60, the thickness of the second silicon steel sheets 61, the number of the first silicon steel sheets 60 and the number of the second silicon steel sheets 61. Figure 8 and Fig. 9 The stator and rotor manufacturing scheme in the embodiment can make the size of the axial air gap 50 more flexible to adjust.

[0047] Option 4 Fig.11As shown, the stator 1 and the rotor 3 are formed by laminating the first silicon steel sheet 60 and the second silicon steel sheet 61. At this time, the size of the axial air gap 50 is determined by the thickness of the first silicon steel sheet 60, the thickness of the second silicon steel sheet 61, the number of the first silicon steel sheet 60 and the number of the second silicon steel sheet 61. Figure 8 and Fig. 9 The stator and rotor manufacturing scheme in the embodiment can also make the size of the axial air gap 50 more flexible to adjust.

[0048] By using a single thickness or a combination of silicon steel sheets of different thicknesses to manufacture the stator 1 and the rotor 3 of the motor, the selection of the size of the axial air gap 50 in the mixed air gap 5 is made more flexible and varied, breaking through the problem that the length of the axial air gap 50 is limited by the size of the silicon steel sheets when the stator 1 and the rotor 3 of the motor are manufactured using traditional silicon steel sheets of single thickness.

[0049] Therefore, the present invention adopts the above-mentioned hybrid air-gap double-pole motor, which can effectively expand the overlapping area between the stator poles and the rotor poles of the motor in the alignment position without changing the outer diameter, stack length, air gap length and stator and rotor pole arc coefficient of the motor, thereby reducing the air gap magnetic resistance, increasing the air gap magnetic flux density of the motor, and improving the output torque density and efficiency of the motor, thereby effectively solving the problems of low output torque density and low efficiency of traditional double-pole motors and expanding the application field of double-pole motors.

[0050] It should be noted that the present invention is based on a three-phase 6 / 4-pole (the number of motor phases m is 3, the number of stator poles N s is 6, the number of rotor poles is N r Taking 4) double salient pole motor as an example, a hybrid air gap double salient pole motor is described. The hybrid air gap double salient pole motor provided by the present invention has multiple phase numbers m, stator pole numbers N s and rotor pole number N r Combination, its phase number m, stator pole number N s and rotor pole number N r Including but not limited to the following relationship: stator pole number N s and rotor pole number N r The lowest common multiple is the number of motor phases m and the number of rotor poles N r The product of . Therefore, any combination of the number of phases, the number of stator poles, and the number of rotor poles that satisfy the above relationship can be used as the number of phases, the number of stator poles, and the number of rotor poles of the double-salient pole motor proposed in the present invention. The present invention only lists the stator 1 and the rotor 3 manufacturing schemes under the combination of single thickness and two thickness silicon steel sheets in the embodiment, but the motor structure proposed in the present invention can adopt a combination of three, four, or other multiple thickness silicon steel sheets. Similarly, the present invention only lists the modular scheme of stator 1 using 2 modules in the embodiment, while the motor structure proposed in the present invention can adopt a stator modular scheme of other numbers of modules.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A hybrid air-gap double-salient-pole motor, characterized in that: It includes a stator, a rotor and a winding coil, wherein the stator and the rotor are both salient pole structures, and the rotor is coaxially arranged in the middle of the stator; there is a mixed air gap between the stator and the rotor, which is rectangular in shape and includes an axial air gap and a radial air gap; The stator comprises a stator pole and a stator yoke, wherein the stator pole is formed by extending the inner wall of the stator yoke inwardly along the radial direction, the stator poles are arranged on the inner wall of the stator yoke at equal intervals in the circumferential direction, the surface of the stator pole adopts a concave-convex structure, and the size and shape of each stator pole are the same; The rotor includes a rotor pole and a rotor yoke. The rotor pole is formed by extending outward in the radial direction of the outer wall of the rotor yoke. The rotor poles are arranged on the outer wall of the rotor yoke at equal intervals in the circumferential direction. The surface of the rotor pole adopts a concave-convex structure, and the concave-convex structure matches the concave-convex structure of the stator pole to form the mixed air gap, and the size and shape of each rotor pole are the same.

2. A hybrid air-gap double-salient-pole motor according to claim 1, characterized in that: The stator has a stator pole number N s and the number of rotor poles N of the rotor r The lowest common multiple is the number of motor phases m and the number of rotor poles N r The product of is expressed as: LCM(N s ,N r )=mN r 。 3. The hybrid air-gap double-salient-pole motor according to claim 1, characterized in that: The winding coil adopts concentrated winding, and the winding coil is wound on each stator pole with the same number of turns; the winding coil is divided into m phases according to the number of phases of the motor, and each phase winding is composed of the winding coils on the stator poles separated by m-1.

4. The hybrid air-gap double-salient-pole motor according to claim 1, characterized in that: The connection modes of the windings of each phase of the winding coil are completely the same and all adopt direct current power supply mode.

5. The hybrid air-gap double-salient-pole motor according to claim 1, characterized in that: The stator and the rotor are both made by laminating silicon steel sheets, and the length of the axial air gap in the mixed air gap is adjusted by using a combination of silicon steel sheets of a single thickness or different thicknesses.

6. The hybrid air-gap double-salient-pole motor according to claim 1, characterized in that: The stator adopts a modular structure and is assembled and formed by keyways arranged in the stator yoke.

Images