A stator multi-tooth hybrid permanent magnet memory motor

Abstract

The present invention belongs to the field of permanent magnet memory motor design and discloses a stator multi-tooth hybrid permanent magnet memory motor, comprising a stator, a rotor, an armature winding, an excitation winding, and a rotating shaft. The stator includes a stator yoke, the inner side of which is fixedly connected to stator teeth, the stator yoke between two adjacent stator teeth is inlaid with a high-coercivity permanent magnet, the stator teeth are provided with a plurality of small teeth at one end away from the stator yoke, and a low-coercivity permanent magnet is fixedly connected between the small teeth at the ends of two adjacent stator teeth; the armature winding and the excitation winding are wound around the stator. By arranging two permanent magnets in parallel in a magnetic concentrating manner and applying a pulse current simultaneously to change the state and direction of the low-coercivity permanent magnet, a wide range of adjustment of the motor's no-load air gap magnetic field is achieved; the multi-tooth stator structure can shorten the distance between adjacent stator teeth, reduce the amount of permanent magnets used, and improve the torque density and reduce torque pulsation while improving the utilization rate of the permanent magnets.

Description

Technical Field

[0001] The present invention belongs to the field of permanent magnet memory motor design, and in particular relates to a stator multi-tooth hybrid permanent magnet memory motor. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) offer advantages such as high power / torque density, high efficiency, high reliability, and diverse structural configurations. They are widely used in electric vehicles, robotic servos, wind power generation, and other fields, and hold broad development prospects. However, conventional PMSMs use high-coercivity neodymium iron boron (NdFeB) as their permanent magnet material, making the air gap magnetic field difficult to adjust, limiting their constant power operating range. In contrast, memory motors employ instantaneous pulsed currents to alter the magnetization level of low-coercivity permanent magnets, enabling flexible adjustment of the air gap magnetic field. Furthermore, these motors exhibit negligible losses in the electric excitation during magnetic field adjustment, making them well-suited for a wide range of speed regulation applications and worthy of further investigation.

[0003] The concept of a memory motor was first proposed by German scholar V. Ostovic. Its stator structure is identical to that of a conventional permanent magnet synchronous motor, while the rotor is a "sandwich" structure consisting of tangentially magnetized AlNiCo permanent magnets, a magnetic barrier, and a rotor core, press-fitted circumferentially onto a non-magnetic shaft. Due to the low coercivity of AlNiCo permanent magnets and their ability to undergo repeated, irreversible magnetization and demagnetization, this unique structure allows for flexible adjustment of the air gap magnetic field while minimizing the impact of quadrature-axis armature reaction on the air gap magnetic field.

[0004] However, this motor structure also has its drawbacks. The coercive force of the AlNiCo permanent magnets used is lower than that of NdFeB permanent magnets, and the air gap flux density of the motor does not reach the level of the original NdFeB permanent magnets as the excitation source, which reduces the electromagnetic performance of the motor. Placing the permanent magnets on the rotor requires the armature winding to perform both drive control and short-term magnetic field control, which greatly increases the difficulty of online magnetic field adjustment.

[0005] Therefore, to address the issue of insufficient magnetic flux, some researchers have proposed using a hybrid excitation method using AlNiCo and NdFeB permanent magnets. Furthermore, to address the challenge of the armature winding also regulating magnetic flux, researchers have proposed a stator hybrid permanent magnet memory motor (HPMMM) in which the field regulating winding is separated from the armature winding. This HPMMM not only offers flexible regulation of the air gap magnetic field but also exhibits excellent robustness, attracting widespread attention from researchers both domestically and internationally. However, achieving a wide range of motor speeds and the high cost of permanent magnets pose challenges, as do increasing their utilization and achieving high torque with fewer permanent magnets. Summary of the Invention

[0006] In order to solve the deficiencies mentioned in the above background technology, the object of the present invention is to provide a stator multi-tooth hybrid permanent magnet memory motor.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A stator multi-tooth hybrid permanent magnet memory motor comprises a stator, a rotor, an armature winding, an excitation winding and a rotating shaft, wherein the rotor is located inside the stator and is sleeved on the rotating shaft;

[0009] The stator includes an outermost stator yoke portion, an inner side of which is fixedly connected to a stator tooth, a high-coercivity permanent magnet is embedded in the stator yoke portion located between two adjacent stator teeth, and a plurality of small teeth are formed on one end of the stator teeth away from the stator yoke portion, and a low-coercivity permanent magnet is fixedly connected between the small teeth located at the ends of two adjacent stator teeth;

[0010] The armature winding is wound on a single tooth of the stator tooth close to the stator yoke;

[0011] The excitation winding is wound around the low-coercive force permanent magnet.

[0012] Furthermore, the magnetization mode of the high coercive force permanent magnets is circumferential magnetization, and the magnetization directions of two adjacent high coercive force permanent magnets are opposite.

[0013] Furthermore, the magnetization mode of the low-coercive-force permanent magnets is circumferential magnetization, and the magnetization directions of two adjacent low-coercive-force permanent magnets are opposite.

[0014] Furthermore, the number of the high-coercive force permanent magnets and the low-coercive force permanent magnets is the same and an even number, and they are arranged in parallel.

[0015] Furthermore, the inner end and the outer end of the end portion of the stator tooth are both arc structures, and the width of each small tooth is the same.

[0016] Furthermore, the rotor is arranged on the radially inner side of the stator teeth, and the rotor is a salient pole structure;

[0017] The rotor includes a rotor core, and rotor teeth are fixedly connected to the circumference of the rotor core.

[0018] Furthermore, the armature winding is a double-layer concentrated winding structure.

[0019] Furthermore, the excitation winding is a single-layer concentrated winding structure.

[0020] Furthermore, the number of stator poles, rotor poles, and stator teeth of the motor satisfy the following relationship:

[0021] N r =nN s +1

[0022] Among them, Ns is the number of stator poles, N r is the number of rotor poles, and n is the number of stator teeth.

[0023] Furthermore, the excitation winding thickness, low coercive force radial thickness and stator tooth radial thickness of the motor satisfy the following relationship:

[0024] h=2×d+h

[0025] sm

[0026] Among them, h s is the radial thickness of the stator teeth, d is the thickness of the excitation winding, h m is the radial thickness of the low coercive force permanent magnet.

[0027] The nouns, conjunctions or adjectives involved in the above technical solution are explained as follows:

[0028] A fixed connection is a connection in which parts or components are fixed without any relative movement. There are two types of connections: detachable and non-detachable.

[0029] (1) A removable connection is a method of fastening components together using screws, splines, wedge pins, etc. This type of connection allows for disassembly during maintenance without damaging the components. However, the connectors used must be of the correct specifications (e.g., length of bolts, keys, wedge pins) and properly tightened.

[0030] (2) Non-detachable connections mainly refer to welding, riveting, and tenoning. Since they require forging, sawing, or oxygen cutting to disassemble during repair or replacement, spare parts generally cannot be reused. At the same time, when making connections, attention should be paid to workmanship quality, technical inspection, and remedial measures (such as calibration, polishing, etc.).

[0031] A threaded connection refers to a detachable connection in which the connected parts are connected together using a threaded part (or the threaded part of the connected parts).

[0032] A sliding connection is when two objects are in contact but not fixed and can slide relative to each other.

[0033] A rotational connection is a connection between parts that allows the parts to rotate relative to each other.

[0034] Beneficial effects of the present invention:

[0035] 1. The overall structure of the present invention is simple, and both the stator and rotor are salient pole structures, which have simple structure and good robustness.

[0036] 2. The two permanent magnets in the present invention are structurally arranged in parallel, and the magnetization directions of the two adjacent permanent magnets are opposite, which can effectively concentrate the magnetism. By applying a pulse current to the excitation winding to change the state and direction of the low-coercive force permanent magnet, a wide range of adjustment of the no-load air gap magnetic field of the motor is achieved.

[0037] 3. The motor of the present invention adopts a stator multi-tooth structure, which can shorten the distance between adjacent stator teeth, reduce the amount of permanent magnets used, and improve the utilization rate of permanent magnets while increasing torque density and reducing torque pulsation.

[0038] 4. In the present invention, both the armature winding and the excitation winding adopt concentrated winding, and the end size is very short, which reduces the waste of copper wire at the winding end and can make the structure size more compact; the winding can be automatically wound, the process is simple, the production efficiency is greatly improved, and large-scale automated production is realized.

[0039] 5. The present invention adopts two kinds of permanent magnets with different coercive forces as magnetic sources. The permanent magnet with high coercive force is used as the main excitation to improve the torque density of the motor. Under the action of pulsed magnetic modulation current, the magnetic flux of the permanent magnet with low coercive force can undergo irreversible changes in direction and size, effectively adjusting the air gap magnetic density in the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0041] Figure 1 This is a cross-sectional view of a motor having two stator teeth according to the present invention;

[0042] Figure 2 This is a cross-sectional view of a motor having three stator teeth according to the present invention;

[0043] Figure 3 A magnetic flux path diagram of the excitation winding of the motor with two stator teeth of the present invention magnetizing the low coercive force permanent magnet;

[0044] Figure 4 A magnetic flux path diagram of the excitation winding of the motor with three stator teeth of the present invention magnetizing the low coercive force permanent magnet;

[0045] Figure 5 A magnetic flux path diagram of demagnetizing a low-coercive-force permanent magnet by an excitation winding of a motor having two stator teeth according to the present invention;

[0046] Figure 6 This is a magnetic flux path diagram of the excitation winding of the motor with three stator teeth of the present invention for demagnetizing the low coercive force permanent magnet.

[0047] In the figure: 1. stator; 11. stator yoke; 12. high-coercivity permanent magnet; 13. low-coercivity permanent magnet; 14. stator teeth; 2. rotor; 21. rotor core; 22. rotor teeth; 3. armature winding; 4. excitation winding; 5. rotating shaft. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] like Figure 1-6 As shown, the present invention provides an embodiment, a stator multi-tooth hybrid permanent magnet memory motor, comprising a stator 1, a rotor 2, an armature winding 3, an excitation winding 4 and a rotating shaft 5, wherein the rotor 2 is located inside the stator 1 and is sleeved on the rotating shaft 5;

[0051] The stator 1 includes an outermost stator yoke 11, with stator teeth 14 fixedly connected to the inner side of the stator yoke 11. A high-coercivity permanent magnet 12 is embedded in the stator yoke 11 between two adjacent stator teeth 14. A plurality of small teeth are formed on the end of the stator teeth 14 away from the stator yoke 11. A low-coercivity permanent magnet 13 is fixedly connected between the small teeth at the ends of two adjacent stator teeth 14.

[0052] The armature winding 3 is wound on a single stator tooth 14 close to the stator yoke 11;

[0053] The excitation winding has four turns wound around the low-coercive-force permanent magnet 13 .

[0054] Specifically, the high coercive force permanent magnets 12 are all magnetized in a circumferential direction, and the magnetization directions of two adjacent high coercive force permanent magnets 12 are opposite.

[0055] Specifically, the magnetization mode of the low-coercive-force permanent magnets 13 is circumferential magnetization, and the magnetization directions of two adjacent low-coercive-force permanent magnets 13 are opposite.

[0056] Specifically, the number of the high-coercive force permanent magnets 12 and the low-coercive force permanent magnets 13 is the same and an even number, and they are arranged in parallel.

[0057] Specifically, the high coercive force permanent magnet 12 is a neodymium iron boron permanent magnet, and the low coercive force permanent magnet 13 is an aluminum nickel cobalt permanent magnet.

[0058] Specifically, the inner end and the outer end of the distal end of the stator tooth 14 are both arc structures, and the width of each small tooth is the same.

[0059] Specifically, the rotor 2 is disposed radially inward of the stator teeth 14. The rotor 2 is a salient pole structure formed by laminating silicon steel sheets. The rotor 2 includes a rotor core 21, to which rotor teeth 22 are fixedly connected on the circumferential side.

[0060] Specifically, the armature winding 3 is a double-layer concentrated winding structure.

[0061] Specifically, the excitation winding 4 is a single-layer concentrated winding structure.

[0062] Specifically, the number of stator poles N of the motor s 、Number of rotor poles r , the number of stator teeth n satisfies the following relationship:

[0063] N r =nN s +1

[0064] Among them, N s is the number of stator poles, N r is the number of rotor poles, and n is the number of stator teeth.

[0065] Specifically, the excitation winding thickness, low coercive force radial thickness and stator tooth radial thickness of the motor satisfy the following relationship:

[0066] h=2×d+h

[0067] sm

[0068] Among them, h s is the radial thickness of the stator teeth, d is the thickness of the excitation winding, h m is the radial thickness of the low coercive force permanent magnet.

[0069] The overall structure of the present invention is simple, and both the stator and the rotor are salient pole structures, which has a simple structure and good robustness.

[0070] The two permanent magnets in the present invention are structurally arranged in parallel. The magnetization directions of the two adjacent high-coercive force permanent magnets 12 are opposite, which can effectively concentrate the magnetism. By applying a pulse current to the excitation winding 4 to change the state and direction of the low-coercive force permanent magnet, a wide range of adjustment of the no-load air gap magnetic field of the motor is achieved.

[0071] The motor of the present invention adopts a stator multi-tooth structure, which can shorten the distance between adjacent stator teeth 14, reduce the amount of permanent magnets used, and improve the utilization rate of permanent magnets while increasing torque density and reducing torque pulsation.

[0072] In the present invention, both the armature winding 3 and the excitation winding 4 adopt concentrated winding, and the end size is very short, which reduces the waste of copper wire at the winding end and can make the structural size more compact; the winding can be automatically wound, the process is simple, the production efficiency is greatly improved, and large-scale automated production is realized.

[0073] The present invention adopts two kinds of permanent magnets with different coercive forces as magnetic sources. The permanent magnet with high coercive force is used as the main excitation to improve the torque density of the motor. Under the action of pulsed magnetization current, the magnetic flux of the permanent magnet with low coercive force can undergo irreversible changes in direction and size, effectively adjusting the air gap magnetic density in the motor.

[0074] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0075] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A stator multi-tooth hybrid permanent magnet memory motor, comprising a stator (1), a rotor (2), an armature winding (3), an excitation winding (4) and a rotating shaft (5), characterized in that: The rotor (2) is located inside the stator (1) and is sleeved on the rotating shaft (5); The stator (1) includes an outermost stator yoke (11), a stator tooth (14) is fixedly connected to the inner side of the stator yoke (11), a high coercive force permanent magnet (12) is embedded on the stator yoke (11) between two adjacent stator teeth (14), a plurality of small teeth are provided on one end of the stator tooth (14) away from the stator yoke (11), and a low coercive force permanent magnet (13) is fixedly connected between the small teeth at the ends of two adjacent stator teeth (14); The armature winding (3) is wound on a single tooth of the stator tooth (14) close to the stator yoke (11); The excitation winding (4) is wound around the low-coercive-force permanent magnet (13); The magnetization method of the high coercive force permanent magnet (12) is circumferential magnetization, the magnetization method of the low coercive force permanent magnet (13) is circumferential magnetization, and the high coercive force permanent magnet (12) and the low coercive force permanent magnet (13) are in a parallel structure; The number of stator poles, rotor poles, and stator teeth of the motor satisfy the following relationship: in, is the number of stator poles, is the number of rotor poles, and n is the number of stator teeth.

2. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The magnetization directions of two adjacent high-coercive force permanent magnets (12) are opposite.

3. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The magnetization directions of two adjacent low-coercive force permanent magnets (13) are opposite.

4. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The number of the high-coercive force permanent magnets (12) and the low-coercive force permanent magnets (13) is the same and both are an even number.

5. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The inner end and the outer end of the end portion of the stator tooth (14) are both arc structures, and the width of each small tooth is the same.

6. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The rotor (2) is arranged on the radially inner side of the stator teeth (14), and the rotor (2) is a salient pole structure; The rotor (2) comprises a rotor core (21), and rotor teeth (22) are fixedly connected to the circumferential side of the rotor core (21).

7. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The armature winding (3) is a double-layer concentrated winding structure.

8. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The excitation winding (4) is a single-layer concentrated winding structure.

9. The stator multi-tooth hybrid permanent magnet memory motor according to claim 1, characterized in that: The thickness of the motor's excitation winding, the radial thickness of the low-coercive-force permanent magnet, and the radial thickness of the stator teeth satisfy the following relationship: in, is the radial thickness of the stator teeth, is the thickness of the excitation winding, is the radial thickness of the low coercive force permanent magnet.

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