CN117277634A - A permanent magnet vernier motor - Google Patents

Abstract

The invention discloses a permanent magnet vernier motor, which belongs to the technical field of motors and comprises a stator structure and a rotor structure, wherein the stator structure comprises stator teeth and stator yokes, the stator teeth are connected with the stator yokes, stator grooves are formed between two adjacent stator teeth, the rotor structure is uniformly arranged on the inner side or the outer side of the stator structure and forms a gap with the stator structure, the rotor structure comprises rotor teeth and rotor magnetic steel, and the rotor magnetic steel is distributed among the rotor teeth; wherein the stator tooth top portion and the notch area are composed of a plurality of different materials, each group comprises all materials appearing in the stator tooth top portion and the notch area, the materials are encoded, k groups of codes are provided, k is required to satisfy j=k/m, wherein m is a phase number, and j is any integer; let the number of stator teeth occupied by each group of codes be n, the number of stator teeth Z needs to satisfy: z=n·k, and if the number of pole pairs of each set of codes is i, the number of pole pairs of the modulation ring formed by the stator tooth crest portion and the notch region is pm=i·k.

Description

A permanent magnet vernier motor

Technical field

The invention belongs to the field of motor technology, and particularly provides a permanent magnet vernier motor.

Background technique

The permanent magnet vernier motor is a motor based on the principle of magnetic field modulation that can achieve high efficiency and high torque density at low speeds. Its characteristic is to produce new output characteristics by changing the spatial phase spectrum or phase of the original magnetic field. Its high torque density and low rated speed make it widely used in low-speed and high-torque systems. However, the structures of existing permanent magnet vernier motors are mostly the same. Taking the bilateral permanent magnet vernier motor as an example, most permanent magnets are evenly placed on the stator teeth and the rotor side, and the stator teeth mostly adopt a split tooth structure. However, the relatively fixed structure also has a certain impact on the slot-pole matching of the permanent magnet vernier motor. According to the slot pole matching formula of the permanent magnet vernier motor:

(1)

Among them, Z is the number of stator teeth, t is the number of modulation teeth of a single stator tooth, Pr is the number of rotor pole pairs, and Pw is the number of winding pole pairs. It can be seen from its slot-pole matching formula that when the number of stator slots and the number of winding pole pairs remain unchanged and t increases by 1, Pr increases by Z. When Z is large, the polar logarithm variation range of Pr is also large. In particular, when the motor is operating at a slightly higher speed, the frequency of the motor is higher due to the increase in the number of rotor pole pairs, which will lead to higher eddy current losses and hysteresis losses.

Contents of the invention

In view of the above problems, the present invention proposes a new permanent magnet vernier motor that changes the material of the stator teeth and changes the number of modulation ring pole pairs, thereby changing the number of rotor pole pairs and improving the utilization rate of permanent magnets.

In order to achieve the above object, the present invention provides the following technical solution: a permanent magnet vernier motor, including a stator structure and a rotor structure. The stator structure includes stator teeth and a stator yoke. The stator teeth are connected to the stator yoke. Two adjacent stator teeth Stator slots are formed between them, and the rotor structure is uniformly placed inside or outside the stator structure to form a gap with the stator structure. The rotor structure includes rotor teeth and rotor magnets, and the rotor magnets are distributed between the rotor teeth; wherein the stator The tooth top part and the notch area are composed of multiple different materials. The materials are arranged in groups in order. Each group includes all the materials that appear in the stator tooth top part and the notch area. For these materials Code, assuming there are k sets of codes, then k needs to satisfy j=k/m, where m is the number of phases and j is any integer; assuming that the number of stator teeth occupied by each set of codes is n, the number of stator teeth Z needs to satisfy: Z =n·k, if the number of pole pairs in each group of codes is i, then the number of pole pairs in the modulation ring formed by the stator tooth top part and the slot area is Pm=i·k. The slot-pole coordination of this motor satisfies:

(1)

Among them, Pw is the number of armature winding pole pairs in the stator core and armature winding area, Pm is the number of modulation ring pole pairs, and Pr is the number of rotor pole pairs.

Preferably, the materials in the group are sequentially distributed in different areas within the group, and each material appears in one or more areas within the group.

Preferably, the material includes magnetic steel and/or iron blocks.

Preferably, air areas are interspersed between the magnets and/or iron blocks.

Preferably, an additional magnet is provided at the interval between the tops of each stator tooth.

The present invention has the following beneficial effects: The present invention proposes a new type of permanent magnet vernier motor. When the number of stator slots and the number of winding pole pairs remain unchanged, the number of pole pairs of the modulation ring can be changed by changing the stator tooth material, thereby Adjust the number of rotor pole pairs. Through the structure proposed by the invention, the utilization rate of the permanent magnet can be improved. Compared with the existing permanent magnet vernier motor with a split-tooth structure, the permanent magnet vernier motor proposed by the present invention can reduce the number of pole pairs of the rotor while keeping the number of stator slots and the number of stator winding pole pairs unchanged, thereby improving the performance of the motor. When the speed is higher, the iron core loss of the motor can be reduced.

Description of the drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore do not It should be regarded as a limitation of the scope. For those skilled in the art, other relevant drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic plan view of the first embodiment of the present invention;

Figure 2 is a schematic structural diagram of a second embodiment of the present invention;

Figure 3 is a plan structure diagram equivalent to Figure 2;

Figure 4 is a schematic diagram of the tooth slot structure of the stator in the prior art;

Figure 5 is a schematic diagram of the tooth slot structure of the stator in the present invention.

Reference signs: 1-stator core and armature winding area; 101-first material; 102-second material; 103-third material; 104-fourth material; 105-fifth material; 106-sixth material ; 107-seventh material; 108-eighth material; 2-stator tooth top part and notch area; 201-ninth material; 202-tenth material; 203-eleventh material; 204-twelfth material; 205-Thirteenth material; 206-Fourteenth material; 207-Fifteenth material; 208-Sixteenth material; 209-Seventeenth material; 3-Rotor area; 4-Armature winding; 5-Magnetic steel ; 6-Iron block.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the scope of protection of the present invention. Accordingly, the following detailed description of embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but rather to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the scope of protection of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The directions indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" etc. or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more than two, unless otherwise explicitly and specifically limited.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise expressly provided and limited, the term "above" or "below" a first feature of a second feature may include direct contact between the first and second features, or may also include the first and second features. Not in direct contact but through additional characteristic contact between them. Furthermore, the terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above and diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

Example

The following are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the following examples. All technical solutions that fall under the idea of the present invention belong to the protection scope of the present invention.

Referring to Figure 1 of the description, a permanent magnet vernier motor is characterized in that it includes a stator structure and a rotor structure. The stator structure includes stator teeth and a stator yoke. The stator teeth are connected to the stator yoke, and between two adjacent stator teeth A stator slot is formed, and the rotor structure is uniformly placed inside or outside the stator structure to form a gap with the stator structure. The rotor structure includes rotor teeth and rotor magnets, and the rotor magnets are distributed between the rotor teeth; where the tops of the stator teeth The points and the notch area are composed of multiple different materials. The materials are arranged in groups in order. Each group includes all the materials that appear in the stator tooth top part and the notch area. These materials are coded. , assuming there are k groups of codes, then k needs to satisfy j=k/m, where m is the number of phases and j is any integer; assuming that the number of stator teeth occupied by each group of codes is n, the number of stator teeth Z needs to satisfy: Z=n ·k, if the number of pole pairs in each group of codes is i, then the number of pole pairs in the modulation ring formed by the stator tooth top part and the notch area is Pm=i·k. The slot-pole coordination of this motor satisfies:

(1)

Among them, Pw is the number of armature winding pole pairs in the stator core and armature winding area, Pm is the number of modulation ring pole pairs, and Pr is the number of rotor pole pairs. The slot-pole fit of the motor is changed by adjusting the material of the stator tooth top portion and the slot area.

The working principle of the motor has a lot to do with the cooperation of the slot poles of the motor. Specifically, the surface of the motor rotor is equipped with evenly distributed magnets, the surface of the stator is slotted, stator teeth are formed between two adjacent stator slots, and the stator winding is placed in the slot. , can generate electromagnetic torque and induced electromotive force, and is a key component of the motor for energy conversion. When the motor is working, three-phase alternating current will flow into the stator winding of the motor to generate a rotating magnetic field. The rotating magnetic field generated by the stator winding interacts with the rotor permanent magnet, causing the rotor to generate torque under the action of the magnetic field, thereby realizing the rotation of the motor. In addition, when the stator tooth top part and part of the notch are made of magnets, the stator magnets will be modulated by the rotor teeth, forming harmonics with different pole pairs and electrical rotation speeds on the air gap side. In the same way, the rotor magnets will also be modulated by the stator teeth, forming various harmonics. The magnetic field generated by the armature winding on the stator is modulated by the rotor teeth, and a harmonic magnetic field is also generated on the air gap side. Some of the harmonic magnetic fields generated by the armature winding can interact with the harmonic magnetic fields generated by the stator magnets and rotor magnets at the same time, thus producing constant torque. Through the effect of bidirectional magnetization, the torque density of the bidirectional magnetic field modulation motor is greatly improved. Therefore, the present invention can change the number of pole pairs of the modulation ring by changing the material of the stator teeth, thereby adjusting the number of pole pairs of the rotor and thereby reducing the core loss of the motor when the motor speed is high.

Referring to Figure 1 of the description, the structure of the first embodiment of the present invention is shown, which includes a stator core and armature winding area 1, a stator tooth top part and a notch area 2, and a rotor area 3, where the stator tooth top part and the notch area are The material combination in 2 is that the first material 101 corresponds to iron, which is encoded as 0; the second material 102 corresponds to air, which is encoded as 1; the third material 103 corresponds to the excitation direction and rotor area 3 rotor Magnets with the same excitation direction are coded as 2; the fourth material 104 corresponds to air, and is coded as 1; the fifth material 105 is the same as the first material 101, and the sixth material 106 is the same as the second material 105. The material 102 is the same, the seventh material 107 is the same as the third material 103, the eighth material 108 is the same as the fourth material 104, and the same code 0121 can be obtained. Then the material combination of the stator tooth top part and the notch area 2 can be expressed as 0121|0121|0121|0121... using a series of codes. Suppose there are k sets of codes in total, then k needs to satisfy j=k/m, where m is the phase number and j is any integer. Assume that the number of stator teeth occupied by each group of codes is n, and the number of stator teeth Z needs to satisfy: Z=n·k. If the number of pole pairs in each group of codes (corresponding to the stator tooth top part and the structure of notch area 2) is i, then the number of pole pairs in the modulation ring formed by area 2 is Pm=i·k.

Referring to Figures 2-3 of the description, which is a structural diagram of the second embodiment of the present invention, the stator part: the stator yoke portion has 24 stator teeth placed in sequence along the circumferential direction, wherein magnets are placed every three stator teeth, and two adjacent stator teeth are placed. Between the stator teeth is the stator slot, and the armature winding is placed in the stator slot, which is a 3-phase motor. Corresponding to Figure 3, the ninth material 201 and the seventeenth material 209 are magnetic steel, the tenth material 202, the twelfth material 204, the fourteenth material 206 and the sixteenth material 208 are air. The material 203, the thirteenth material 205 and the fifteenth material 207 are iron blocks. If coded according to the aforementioned material combination, it will be 21010101|21010101|21010101|...|21010101, where k=6, n=4, i=3.

Rotor part: 20 empty slots are placed in the rotor yoke part along the circumferential direction, and permanent magnets are embedded in the empty slots. Two adjacent slots are separated by rotor teeth. Permanent magnets are embedded in the iron core and can form bidirectional magnetic field modulation under some specified or extended stator topologies. That is, the magnetic lines of force generated by the rotor-side magnets can travel from the stator-side iron core teeth, and the magnetic lines of force generated by the stator-side magnets can travel from the rotor. Side iron core walking.

For traditional permanent magnet vernier motors, the cogging structure of the stator can form a series of square wave magnetic fluxes on the air gap side, and the number of pole pairs of the flux flux is the number of teeth of the stator. As shown in Figure 4. In this way, the number of pole pairs of the modulation teeth Pm = the number of stator teeth Z, and the number of rotor pole pairs Pr = |Z-Pw| = |Pm-Pw|. For the structure proposed by the present invention, as shown in Figure 5, when the top of the stator teeth is placed with magnets one stator tooth apart, that is, n=2, the stator tooth material is composed of magnet steel-air-iron block-air circulation. In the square wave formed by the stator tooth slots, the number of pole pairs is half of the number of stator teeth, then Pr=|Z/2-Pw|=|Pm-Pw|. Compared with the original structure, while keeping Pw unchanged, the Pr of this structure is reduced. Pr is reduced. For occasions with higher speed, this structure can be used to reduce eddy current losses. The structure proposed by the present invention has different n value settings and different stator tooth material selections, which will produce a lot of slot-pole matching combinations. At the same time, because its structure is different from the existing split-tooth permanent magnet vernier motor, this greatly enriches the diversity of slot pole matching options for permanent magnet vernier motors. In addition, magnets are installed on the stator teeth to form a bilateral permanent magnet excitation structure. When the motor core is not saturated, a richer and wider amplitude can be obtained than the traditional single stator permanent magnet or single rotor permanent magnet. The high air gap magnetic field operates at harmonics and obtains a larger flux linkage, thereby inducing a higher back electromotive force and increasing the power density of the motor.

For example, the bilateral permanent magnet magnetic field modulation motor has a 6-slot stator and Pw=1. Under the traditional slot permanent magnet structure, the number of rotor pole pairs Pr=Z-Pw=5. With the structure described in the present invention, Pr=Z/n·i-1. In this way, n takes 2 and i takes 1, then Pr=2, and the number of rotor pole pairs can be reduced. After simulation comparison, at the same rotation speed of 3000rpm, the eddy current loss of this structure can be reduced by about 30% compared to the structure with five pairs of poles.

The above embodiments are only for illustrating the technical concepts and characteristics of the present invention. Their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly. They cannot limit the scope of protection of the present invention. All equivalent changes or modifications made based on the spirit and essence of the present invention should be included in the protection scope of the present invention.

Claims (5)

1. The permanent magnet vernier motor is characterized by comprising a stator structure and a rotor structure, wherein the stator structure comprises stator teeth and stator yokes, the stator teeth are connected with the stator yokes, stator grooves are formed between two adjacent stator teeth, the rotor structure is uniformly arranged on the inner side or the outer side of the stator structure and forms a gap with the stator structure, the rotor structure comprises rotor teeth and rotor magnetic steel, and the rotor magnetic steel is distributed among the rotor teeth; the stator tooth top part and the notch area are composed of a plurality of different materials, the materials are circularly arranged in sequence by taking groups as units, each group comprises all materials appearing in the stator tooth top part and the notch area, the materials are coded, k groups of codes are shared, k is required to meet j=k/m, wherein m is a phase number, and j is any integer; let the number of stator teeth occupied by each group of codes be n, the number of stator teeth Z needs to satisfy: z=n·k, and if the number of pole pairs of each set of codes is i, the number of pole pairs of the modulation ring formed by the stator tooth top portion and the notch region is pm=i·k, and the motor slot pole matching satisfies:

（1）

wherein Pw is the pole pair number of the armature winding in the stator core and the armature winding region, pm is the pole pair number of the modulation ring, and Pr is the pole pair number of the rotor.

2. A permanent magnet vernier motor according to claim 1, wherein the materials in the group are distributed sequentially in different regions in the group, each material being present in one or more of the regions in the group.

3. A permanent magnet vernier motor according to claim 2, characterized in that the material comprises magnetic steel and/or iron blocks.

4. A permanent magnet vernier motor according to claim 3, wherein air regions are interposed between the magnet steels and/or the iron blocks.

5. The permanent magnet vernier motor of claim 1 wherein one or more magnetic steels are additionally provided at intervals between the tops of each stator tooth.