WO2021103246A1 - Primary permanent magnet bilateral linear magnetic field modulation electric motor and low magnetic resistance design method therefor - Google Patents

Abstract

Disclosed are a primary permanent magnet bilateral linear magnetic field modulation electric motor and a low magnetic resistance design method therefor. The electric motor structurally comprises two secondary stages (1, 2) which are only composed of salient pole teeth (11, 21), and a primary stage (3) provided with permanent magnets (31) and armature windings (321), wherein the upper and lower secondary stage salient pole teeth (11, 21) are oppositely arranged, and the salient pole teeth (11, 21) play the role of modulating a magnetic field; the surface-mounted permanent magnets (31) with the same excitation direction are distributed at intervals on the tooth crest of a unilateral armature of the primary stage (3), and at the same time, the permanent magnets (31) on two sides of the primary stage (3) are distributed in a staggered manner; a primary iron core uses a modular design; each primary module is only composed of long-strip-shaped armature teeth (33); a semi-closed armature groove or a closed groove is formed between every two adjacent modules; and the armature windings (321) are arranged in the grooves. The electric motor processing difficulty can be effectively reduced; and at the same time, due to the arrangement design of the permanent magnets (31) and the secondary modulation teeth, the magnetic flux path can be effectively simplified, the magnetic resistance on the magnetic flux path is reduced, the magnetic field amplitude of the electric motor is increased, the torque performance is improved, and the application prospects are wide.

Description

A primary permanent magnet bilateral linear magnetic field modulation motor and its low reluctance design method Technical field

The invention relates to the fields of electrical engineering, motor design and control and long-stroke electric motors, in particular to a low-cost and high-performance primary permanent magnet type bilateral linear magnetic field modulation motor and its low reluctance design method, which is suitable for rail transportation and logistics transportation, etc. Linear motion occasions.

Background technique

Due to its simple structure, linear motors can be used as direct-drive motors in long-stroke linear applications, and their huge application value has attracted more and more attention. The existing long-stroke linear application fields mostly use asynchronous motors or induction motors. This type of motor is characterized by simple structure, convenient manufacturing and low cost, but the disadvantage is that the efficiency and thrust density are low, and the former requires additional current configuration. Inverters increase costs, and the latter waste energy. Compared with asynchronous (induction) linear motors, permanent magnet linear motors have the advantages of simple structure, high transmission efficiency, high positioning accuracy, and fast response speed. For traditional permanent magnet linear motors, a large number of permanent magnets or armature windings need to be laid on the long secondary part. Obviously, for the long-stroke field, the use of traditional permanent magnet linear motors will greatly increase the cost of the motor. The primary permanent magnet linear motor, because the permanent magnets and windings are in the primary part, solves the problem of high cost in long-stroke applications. However, since the permanent magnets and armature windings do not move relative to each other, the fundamental wave of the motor cannot be used, resulting in low thrust density of the primary permanent magnet linear motor. The introduction of magnetic field modulation can effectively increase the thrust density of the primary permanent magnet linear motor. The application of permanent magnet linear motor in the field of long stroke provides an important reference.

Chinese invention patent 201820249878.2 discloses a cogged double-sided primary permanent magnet synchronous linear motor. This structure places both permanent magnets and windings in the primary part. The permanent magnets are embedded in the primary core, which can be considered as two flux-switching linear motors. Combined with the structure of the motor, the armature winding does not pass through the permanent magnets and the ends are very short, which is conducive to the improvement of the power density of the motor. However, the motor is essentially a magnetic flux switching motor, which also uses the modulated magnetic field harmonics to work. The modulation and amplification effect of the switching motor structure is not obvious, so it has the problem of low thrust density; and the permanent magnet runs through the entire armature tooth, the amount is large, the utilization rate is low, and the motor manufacturing cost is high.

Chinese invention patent 201910352149.9 discloses a modular primary permanent magnet double-sided switched reluctance motor. This structure places permanent magnets in the upper and lower slots of the armature slot. The two slots in the same slot use two opposite excitation directions. Permanent magnets, the permanent magnets in the same side slot opening are arranged at intervals. Although compared with the general reluctance linear motor, the motor structure proposed by this patent can effectively increase the thrust density of the motor, but because the permanent magnetic field and the armature magnetic field can only A loop is formed by two adjacent armature teeth, and the loop passes through two permanent magnets in the same slot at the same time, so that the motor cannot meet the performance amplification effect, and its best performance can only be 1+1= 2.

Chinese invention patent 201410259315.8 discloses a double-sided primary permanent magnet vernier linear motor. This structure has multiple pairs of permanent magnets on the top of each primary tooth. The effective magnetic flux forms a series loop between the two secondary and uses magnetic field at the same time. The modulation principle can make the linear motor produce a larger thrust density. However, since the magnetic flux loop will pass through the permanent magnets on both sides of the primary, the motor structure cannot form the performance amplification effect of 1+1>2. At the same time, due to the large number of permanent magnet pole pairs, the motor has a large magnetic leakage and the power factor of the motor is biased. In addition, the amount of permanent magnets is relatively large, the utilization rate of permanent magnets is low, and the cost is relatively high.

In summary, the thrust density of the primary permanent magnet linear motor at this stage is generally positively correlated with the amount of permanent magnets. In order to further reduce the manufacturing cost of the motor, it is necessary to further study how to effectively improve the utilization of the permanent magnets of the motor. In addition, the fundamental wave of the primary permanent magnet motor is a non-operating wave, which operates based on the principle of magnetic field modulation. Therefore, in order to significantly increase the thrust density of the primary permanent magnet linear motor, a larger modulation ratio (permanent magnet pole pair number and winding pole pair number This makes the number of pole pairs of the motor windings smaller, which means that the effective magnetic field harmonics need to form a longer magnetic flux path, which leads to an increase in the reluctance of the magnetic circuit and a reduction in the magnetic density amplitude. These problems greatly limit the existence of In order to promote its application in the field of long travel. Therefore, the research on how to maximize the utilization of permanent magnets and the low reluctance design of primary permanent magnet motors is imminent.

Summary of the invention

According to the shortcomings and defects of the prior art, the present invention proposes a low-reluctance primary permanent magnet double-sided linear motor structure suitable for the long-stroke field. This structure can effectively simplify the effective magnetic circuit of the motor and reduce the magnetic resistance of the magnetic flux path to achieve The effect of increasing the magnitude of the magnetic density helps to improve the efficiency of the motor's magnetic field modulation, improve the motor thrust performance, and reduce the cost of the motor. The permanent magnet arrangement design with unipolar unipolarity and opposite polarities on both sides reduces the amount of permanent magnets by half while making the bilateral structure complementary to the magnetic field, increasing the amplitude of the motor back EMF and reducing the back EMF waveform. The distortion rate. The arrangement of permanent magnets and the right design of the secondary salient pole teeth make the magnetic circuit form an effective loop between the upper and lower secondary. The magnetic field simply penetrates through an armature tooth on the primary core, and is not adjacent to it. The armature teeth form a magnetic circuit coupling. Therefore, the secondary does not need a yoke core to provide a magnetic circuit, which can effectively reduce the weight of the motor of the present invention, and at the same time provide a larger slot space for the armature winding, and reduce the motor under the same electrical load. Copper consumption improves motor efficiency. In addition, there is a permanent magnet attached to only one side of each secondary armature tooth, and there is no permanent magnet in the corresponding position on the adjacent tooth, which can significantly reduce the magnetic flux leakage between the motor poles and improve the power factor of the motor.

In order to solve the above-mentioned problems, the design scheme of the present invention is as follows:

A primary permanent magnet double-sided linear magnetic field modulation motor, characterized in that the motor includes an upper secondary (1), a primary (3) and a lower secondary (2), between the upper secondary (1) and the primary (3) It is separated by an upper air gap (4), and the lower secondary (2) and the primary (3) are separated by a lower air gap (5);

The upper secondary (1) is evenly distributed on the upper secondary salient pole teeth (11), the lower secondary (2) is evenly distributed on the lower secondary salient pole teeth (21), the upper secondary salient pole teeth (11) and the lower The secondary salient pole teeth (21) are distributed directly opposite to each other. The primary (3) is a modular design. Each primary module consists of only modular armature teeth (33). Each modular armature tooth (33) adopts asymmetrical design from top to bottom. The modular armature of the primary (3) A primary armature slot (32) is formed between the teeth (33), and a primary armature winding (321) is arranged in the primary armature slot (32). There are two structural design schemes for the primary (3), scheme one: the permanent magnet (31) is surface-mounted on the tooth top of the modular armature tooth (33), at this time the modular armature tooth (33) is designed as a pole shoe Thick, thin pole piece on the other side, the thick side is directly adjacent to the air gap, and the thin side is surface-mounted with a permanent magnet (31), and the thickness of the permanent magnet (31) is the difference between the thickness of the pole piece on both sides. Solution 2: The permanent magnet (31) is placed in the notch position of the primary armature slot (32). At this time, both sides of the modular armature tooth (33) are half of the pole piece thick and half of the pole piece thin, and both sides of the pole piece The positions of the thin and thick are opposite to each other. The thickness of the pole shoes on the adjacent sides of the adjacent modularized armature teeth (33) is the same. The permanent magnet (31) is pasted on the surface of the thinner pole piece across the primary armature teeth (321). The upper surface of the magnet (31) is flush with the surface of the thick pole piece. The excitation direction of the permanent magnets (31) of the above two schemes is perpendicular to the direction of movement, the excitation directions of the permanent magnets (31) on the same side are the same, and the excitation directions of the permanent magnets (31) on different sides are opposite. The core of the modular armature tooth (33) adopts an inverted arrangement design. Therefore, the permanent magnets (31) on the same side are arranged at intervals, and the permanent magnets (31) on different sides are arranged in a staggered arrangement.

Further, the air gap (4) between the upper secondary (1) and the primary (3) and the air gap (5) between the lower secondary (2) and the primary (3) are uniformly distributed and have the same thickness.

Furthermore, the upper secondary salient pole teeth (11) are evenly distributed on the upper secondary (1), the lower secondary salient pole teeth (21) are also evenly distributed on the lower secondary (2), and the upper secondary salient pole teeth (11) are evenly distributed on the lower secondary (2). ) Is equal to the number of the lower secondary salient pole teeth (21), and the cross-sectional shape is all rectangular or isosceles trapezoid.

Furthermore, the permanent magnet (31) of the primary (3) adopts permanent magnet materials such as neodymium iron boron or ferrite, and the modular armature teeth (1) of the upper secondary (1), the lower secondary (2) and the primary (3) 33) All are laminated by high permeability silicon steel sheet materials.

_{Further, the number of pole pairs P w} of the primary armature winding (321) of the primary (3), the number of _{pole pairs P pm of the} permanent magnet (31), the upper secondary salient pole tooth (11) or the lower secondary salient pole tooth (21) The number n _s satisfies the following relationship: n _s =P _w +P _pm .

Furthermore, the primary (3) modular armature tooth (33) iron core is fixed by external mechanical parts to ensure uniform distribution in space. The primary armature winding (321) of the primary (3) adopts a distributed winding, which is single-layer or double-layer winding.

Further, the primary armature slot (32) of the primary (3) is in the form of a semi-closed slot or a closed slot.

Further, the modular armature tooth (33) of the primary (3) presents a centrally symmetrical structure in space.

Furthermore, a low reluctance design method of a primary permanent magnet bilateral linear magnetic field modulation motor is characterized in that it includes the following design steps:

Step 1: Connect the primary back-to-backs of the primary permanent magnet linear motors of two unilateral structures, and form a whole through the same yoke core, and the top of each primary (3) tooth is surface-attached with a permanent magnet (31).

Step 2: To ensure the normal operation of the motor, the excitation of the permanent magnet (31) needs to be set. The excitation directions of the unilateral adjacent permanent magnets (31) of the primary (3) of the present invention are opposite, and the excitation directions of the permanent magnets (31) on the corresponding teeth are the same.

Step 3: In order to make the magnetic field lines form an effective series connection between the upper secondary (1) and the lower secondary (2), to simplify the magnetic circuit and reduce the magnetic resistance, the upper secondary salient pole tooth (11) and the lower secondary The salient pole teeth (21) are arranged directly opposite, and the magnetic field lines do not pass through the primary yoke to form a loop. Therefore, the secondary yoke core is removed, and the primary (3) forms a modular armature tooth (33) structure.

Step 4: Remove the space between the permanent magnets (31) on both sides of the primary (3), leave the permanent magnets (31) in the same direction on one side, and make the excitation directions of the permanent magnets (31) on both sides of the primary (3) be opposite.

Step 5: Replace the removed permanent magnet (31) with an iron core material, and form an integral structure with the modular armature tooth (33).

Step 6: Analyze the magnetic field of the upper air gap (4) and the lower air gap (5) according to the number of pole pairs of the permanent magnet (31) and the upper secondary salient pole teeth (11) or the lower secondary salient pole teeth (21) Harmonic situation, and arrange the primary armature winding (321) with the appropriate number of pole pairs in the primary armature slot (32).

Further, the thickness of the permanent magnet (31), the opening width of the primary armature slot (32), the thickness of the modular armature tooth (33), the upper secondary salient pole tooth (11) and the lower secondary salient pole tooth (21) need to be adjusted. The width is optimized to maximize its electromagnetic performance.

The present invention has the following beneficial effects:

1) Using the principle of magnetic field modulation, the low-speed effective magnetic field is generated through the change of the magnetic permeability caused by the secondary magnetic adjustment tooth, which can effectively increase the thrust density of the motor; the primary permanent magnets are distributed at intervals, and the unilateral permanent magnets are excited in the same direction, ensuring that the motor Under the premise of performance, it can effectively reduce the amount of permanent magnets and reduce the cost of motor manufacturing; the dislocation distribution of the primary permanent magnets and the design of the distribution of the secondary cores make the armature teeth without permanent magnets on one side provide the permanent magnetic field on the other side. Effective magnetic circuit, reduce the reluctance of the magnetic flux path, increase the magnetic density amplitude of the motor, and improve the performance of the motor;

2) The excitation directions of the bilateral permanent magnets are opposite, each effective magnetic circuit passes through only one permanent magnet, and one permanent magnet can provide an effective magnetic field for the other side, so that the motor can achieve the performance amplification effect of 1+1>2; bilateral structure and permanent magnets The misalignment design makes the positioning forces on both sides of the motor cancel each other, reduce the thrust pulsation of the motor, and improve the smoothness of the motor output;

3) The yokeless structure is adopted in the primary stage, which can significantly reduce the weight of the motor, while providing a larger slot space for the motor and improving the utilization rate of the motor space. In the case of the same slot full rate and electrical load, it can effectively reduce the copper consumption of the motor and improve the efficiency of the motor; the primary stage adopts a modular design, and each module is only composed of simple armature teeth, which effectively reduces the difficulty of motor processing and reduces manufacturing cost.

4) The distance between the permanent magnets is large, which reduces the magnetic leakage between the permanent magnets and improves the power factor of the motor.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the present invention;

Figure 2 is an enlarged view of the primary modular armature tooth;

Figure 3 is a schematic diagram of secondary structure parameters;

Figure 4 shows the magnetic field distribution diagram of unilateral and bilateral primary permanent magnet magnetic field modulation linear motors; (a) is the unilateral magnetic field distribution diagram; (b) is the bilateral magnetic field distribution diagram;

Figure 5 is a magnetic field distribution diagram of the present invention;

Fig. 6 is a motor model with permanent magnets arranged in armature slots according to the present invention;

Fig. 7 is a comparison diagram of the magnetic density distribution curve of the present invention and the existing motor structure;

Fig. 8 is a comparison diagram of magnetic density harmonics between the present invention and the existing structure;

Fig. 9 is a comparison diagram of the back EMF of the motor of the present invention and the existing structure;

Figure 10 is a comparison diagram of the positioning force of the motor of the present invention and the existing structure;

Figure 11 is a comparison diagram of thrust waveforms between the present invention and existing structures;

In the figure: upper secondary 1, lower secondary 2, primary 3, upper secondary salient pole tooth 11, lower secondary salient pole tooth 21, permanent magnet 31, primary armature slot 32, primary armature winding 321, modular The armature tooth 33, the upper air gap 4, the lower air gap 5.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "upper", "lower", "upper", "lower", "left", "right", etc. indicate the orientation or position The relationship is based on the orientation or position 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 cannot be understood as a limitation to the present invention.

Example 1

1, the present invention discloses a primary permanent magnet bilateral linear magnetic field modulation motor and its low reluctance design method. The motor structure includes an upper secondary (1), a primary (3) and a lower secondary (2). The secondary (1) and the primary (3) are separated by an upper air gap (4), and the lower secondary (2) and the primary (3) are separated by a lower air gap (5);

The upper secondary (1) is evenly distributed on the upper secondary salient pole teeth (11), the lower secondary (2) is evenly distributed on the lower secondary salient pole teeth (21), the upper secondary salient pole teeth (11) and the lower The secondary salient pole teeth (21) are distributed directly opposite to each other. The primary (3) is a modular design. Each primary module consists of only modular armature teeth (33). Each modular armature tooth (33) adopts asymmetrical design from top to bottom. The modular armature of the primary (3) A primary armature slot (32) is formed between the teeth (33), and a primary armature winding (321) is arranged in the primary armature slot (32). The permanent magnet (31) is surface attached to the tooth top of the modular armature tooth (33). At this time, the modular armature tooth (33) is designed with a thick pole shoe on one side and a thin pole shoe on the other side, and the thick side is directly connected to the The air gaps are adjacent, the permanent magnet (31) is surface-mounted on the thin side, and the thickness of the permanent magnet (31) is the difference between the thickness of the pole shoes on both sides. The excitation direction of the permanent magnets (31) is perpendicular to the direction of movement, the excitation directions of the permanent magnets (31) on the same side are the same, the excitation directions of the permanent magnets (31) on different sides are opposite, and the adjacent modular armature teeth of the primary (3) (33) The core adopts an inverted arrangement design. Therefore, the permanent magnets (31) on the same side are arranged at intervals, and the permanent magnets (31) on different sides are arranged in a staggered arrangement. The low reluctance design method of primary permanent magnet bilateral linear magnetic field modulation motor includes the following design steps:

Step 1: Connect the primary back-to-backs of the primary permanent magnet linear motors of two unilateral structures, and form a whole through the same yoke core, and the top of each primary (3) tooth is surface-attached with a permanent magnet (31).

Step 2: To ensure the normal operation of the motor, the excitation of the permanent magnet (31) needs to be set. The excitation directions of the unilateral adjacent permanent magnets (31) of the primary (3) of the present invention are opposite, and the excitation directions of the permanent magnets (31) on the corresponding teeth are the same.

Step 3: In order to make the magnetic field lines form an effective series connection between the upper secondary (1) and the lower secondary (2), to simplify the magnetic circuit and reduce the magnetic resistance, the upper secondary salient pole tooth (11) and the lower secondary The salient pole teeth (21) are arranged directly opposite, and the magnetic field lines do not pass through the primary yoke to form a loop. Therefore, the secondary yoke core is removed, and the primary (3) forms a modular armature tooth (33) structure.

Step 4: Remove the space between the permanent magnets (31) on both sides of the primary (3), leave the permanent magnets (31) in the same direction on one side, and make the excitation directions of the permanent magnets (31) on both sides of the primary (3) be opposite.

Step 5: Replace the removed permanent magnet (31) with an iron core material, and form an integral structure with the modular armature tooth (33).

Step 6: Analyze the magnetic field of the upper air gap (4) and the lower air gap (5) according to the number of pole pairs of the permanent magnet (31) and the upper secondary salient pole teeth (11) or the lower secondary salient pole teeth (21) Harmonic situation, and arrange the primary armature winding (321) with the appropriate number of pole pairs in the primary armature slot (32).

In order to clearly illustrate the specific implementation of the present invention, the present invention will be described below with reference to the three-phase motor in the drawings. Figure 1 is a half model of the motor of the present invention. It can be seen that the permanent magnets (31) are arranged at intervals in the primary module. On the top of the armature tooth (33), the permanent magnets (31) on the upper and lower sides of the primary (3) are arranged in a staggered manner, and the excitation directions are opposite. The primary (3) modular armature tooth (34) has 18 permanent magnets (31) It is distributed with 9 pairs of poles. The upper secondary (1) and the lower secondary (2) have a simple salient pole structure, the number of salient pole teeth is 10, the primary armature winding (321) is wound in the primary (3) primary armature slot (32), using Distributed winding form, the winding is a pair of poles distribution. Some of the more important parameters that need to be optimized in the primary (3), secondary (1) and (2) of the motor designed in the present invention are shown in Figures 2 and 3.

Figure 4 shows the magnetic field line distribution diagram of the existing motor. For Figure 4(a), it can be seen that the magnetic field on the secondary side of the existing motor presents a pair of poles distribution, but the effective magnetic field lines on the primary side need to pass through multiple secondary permanent magnets and repeatedly penetrate through the air gap to form Close the loop. This makes the magnetic circuit of the motor more complicated, and the magnetic permeability of the magnetic circuit increases, which causes the effective magnetic density of the motor to decrease and the performance of the motor to decrease. For the double-sided structure in Figure 4(b), its essence is a combination of two identical primary permanent magnet single-sided linear motors. The two motors share a primary yoke, and the motor magnetic fields are independent of each other. In addition, because the secondary teeth are staggered by half the pole pitch, the positioning force of the double-sided structure motor is offset, and the back EMF is complementary, so that the back EMF of the motor is more sinusoidal than the single-sided structure, and the thrust is more stable. However, similar to the motor shown in Figure 4(a), the magnetic lines of force also need to repeatedly penetrate and exit the air gap to form an effective circuit. The magnetic resistance of the magnetic circuit is large, which leads to a decrease in the magnetic density of the motor and a loss of performance; Permanent magnets are affixed to the surface of the teeth, which makes the amount of permanent magnets larger and the motor cost higher.

Fig. 5 is a magnetic field distribution diagram of a primary permanent magnet bilateral linear magnetic field modulation motor disclosed by the present invention. It can be seen that the magnetic fields of the structure are connected in series, and the magnetic field lines generated by the upper permanent magnets (31) of the primary (3) pass through the primary armature teeth and the lower The secondary interaction, so the structure can achieve the effect of magnetic field enhancement; at the same time, the permanent magnet (31) above is taken as an example, and its magnetic field lines are generated from the permanent magnet and pass through the primary (3), the lower air gap (5), and the lower air gap in turn. The secondary (2), lower air gap (5), primary (3), upper air gap (4), upper secondary (1), upper air gap (4) return to the upper permanent magnet (31), and its magnetic circuit It is simpler, and the magnetic circuit has a smaller permeance. In addition, this structure reduces the amount of permanent magnets by half compared with the structure shown in Fig. 4(b), and the utilization rate of permanent magnets has been significantly improved.

FIG. 7 is a comparison diagram of the air gap flux density distribution of the motor of the present invention and two existing structures. From the waveform, it can be seen that the flux density of the present invention is similar to model a, but lower than model b. Fig. 8 is a Fourier decomposition diagram of the waveform of Fig. 7. It can be seen that the present invention can modulate the highest two pairs of polar magnetic fields, and model b has the highest 18 pairs of polar magnetic fields. Compared with the present invention and model b, the magnetic field of model a does not have any advantages. In addition, since the winding is divided into two pairs of poles, the two pairs of poles have the greatest impact on the performance of the motor, and the primary permanent magnet structure prevents the fundamental wave (18 pairs of pole magnetic fields) from interacting with the windings, that is, the 18 pairs of pole magnetic fields are invalid magnetic fields. . In summary, the present invention has obvious advantages in the modulation of the working wave, which can reduce the amount of permanent magnets and improve the performance of the motor.

Figure 9 is a comparison diagram of the back EMF of the present invention and the back EMF of the existing motor. It can be seen that the present invention has great advantages in back EMF, indicating that the structure is stronger than the existing model a and model in terms of torque output. b. At the same time, the present invention and its unilateral structure motor (model a) have achieved a significant improvement in the back EMF, achieving a magnetic field enhancement effect of 1+1>2. Figure 10 shows the comparison of the positioning force of the motor. It can be seen that the positioning force of the bilateral structure is smaller, mainly because the bilateral positioning forces cancel each other and reduce the amplitude of the primary positioning force, which also effectively reduces the motor thrust pulsation and improves the motor performance. Figure 11 is a comparison diagram of motor thrust under the same electrical load. It can be seen that the motor of the present invention has the highest average value of thrust, and its thrust output capacity is greater than twice the model a thrust output capacity.

Example 2

The present invention discloses another variable structure motor of a primary permanent magnet bilateral linear magnetic field modulation motor. As shown in Fig. 6, its permanent magnet (31) is placed in the primary slot, and the modular armature tooth (33) The two sides are half of the pole piece thickness, half of the pole piece is thin, and the position of the thickness of the pole piece on both sides is opposite. The thickness of the pole piece on the adjacent side of the adjacent modular armature tooth (33) is the same, and the permanent magnet (31) is horizontal The primary armature tooth (321) is pasted on the surface of the thin pole shoe, and the upper surface of the permanent magnet (31) is flush with the surface of the thick pole shoe. The permanent magnets also present an interval distribution, and the permanent magnets (31) on the upper and lower sides are misaligned and the excitation directions are opposite.

Compared with Embodiment 1, the magnetic field of the motor is also distributed in series, but this embodiment can effectively reduce the reluctance of the armature magnetic circuit and increase the amplitude of the armature magnetic field when the motor is not saturated, thereby improving the performance of the motor. But it will also greatly increase motor losses and reduce motor efficiency. At the same time, the permanent magnet (31) of this structure directly contacts the iron core of the modular armature tooth (33), resulting in greater motor leakage than Embodiment 1, and the power factor will be reduced.

In summary, the present invention discloses a primary permanent magnet double-sided linear magnetic field modulation motor and its low reluctance design method. The motor structure includes two secondary phases consisting of salient pole teeth and one arranged with permanent magnets and armature windings. The upper and lower secondary salient pole teeth are arranged opposite to each other. The salient pole teeth have the effect of modulating the magnetic field. The primary unilateral armature tooth tops are spaced apart from the surface-mounted permanent magnets with the same excitation direction. The magnets are distributed in dislocation and the excitation direction is opposite. The arrangement of permanent magnets enables the motor to use not only the permanent magnets on one side, but also the effective magnetic field generated by the permanent magnets on the opposite side, which improves the utilization of permanent magnets to 1+1>2 The performance amplification effect. The primary core adopts a modular design. Each primary module consists of only elongated armature teeth. A semi-closed armature slot or closed slot is formed between two adjacent modules. The armature windings are arranged in the slot, which can effectively reduce the machining of the motor. Difficulty. At the same time, the arrangement design of permanent magnets and secondary modulation teeth can effectively simplify the magnetic flux path, reduce the reluctance on the magnetic flux path, increase the magnetic field amplitude of the motor, and improve the torque performance. It has a larger application prospect.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims (8)

A primary permanent magnet double-sided linear magnetic field modulation motor, characterized in that the motor includes an upper secondary (1), a primary (3) and a lower secondary (2), between the upper secondary (1) and the primary (3) It is separated by an upper air gap (4), and the lower secondary (2) and the primary (3) are separated by a lower air gap (5); The upper secondary (1) is evenly distributed on the upper secondary salient pole teeth (11), the lower secondary (2) is evenly distributed on the lower secondary salient pole teeth (21), the upper secondary salient pole teeth (11) and the lower The secondary salient pole teeth (21) are arranged directly oppositely; the primary (3) is a modular design, each primary module is only composed of modular armature teeth (33), and each modular armature tooth (33) adopts up and down different Symmetrical design, a primary armature slot (32) is formed between the modular armature teeth (33), and a primary armature winding (321) is arranged in the primary armature slot (32); the primary (3) has the following structure: Structure 1: The permanent magnet (31) is surface attached to the tooth top of the modular armature tooth (33). At this time, the modular armature tooth (33) is designed to have a thick pole shoe on one side and a thin pole shoe on the other side. One side is directly adjacent to the air gap, and the thin side is surface-mounted with the permanent magnet (31). The thickness of the permanent magnet (31) is the difference between the thickness of the pole shoes on both sides; Or structure two: the permanent magnet (31) is placed in the notch position of the primary armature slot (32), at this time, both sides of the modular armature tooth (33) are half the pole piece thickness, half of the pole piece thin, and the poles on both sides The positions of the thickness of the shoes are opposite to each other. The thickness of the pole shoes on the adjacent sides of the adjacent modular armature teeth (33) is the same, and the permanent magnets (31) are pasted on the surface of the thinner pole shoes across the primary armature teeth (321). The upper surface of the permanent magnet (31) is flush with the surface of the thick pole piece; The excitation direction of the permanent magnets (31) is perpendicular to the direction of movement, the excitation directions of the permanent magnets (31) on the same side are the same, the excitation directions of the permanent magnets (31) on different sides are opposite, and the adjacent modular armature teeth of the primary (3) (33) The core adopts an inverted arrangement design. Therefore, the permanent magnets (31) on the same side are arranged at intervals, and the permanent magnets (31) on different sides are arranged in a staggered arrangement. The primary permanent magnet bilateral linear magnetic field modulation motor according to claim 1, characterized in that: the air gap (4) between the upper secondary (1) and the primary (3), the lower secondary (2) and the primary (3) The air gaps (5) between) are uniformly distributed and have the same thickness. The primary permanent magnet bilateral linear magnetic field modulation motor according to claim 1, wherein the upper secondary salient pole teeth (11) are evenly distributed on the upper secondary (1), and the lower secondary salient pole teeth (21) are on the lower The upper secondary (2) is also evenly distributed, the upper secondary salient pole teeth (11) and the lower secondary salient pole teeth (21) have the same number, and the cross-sectional shapes are all rectangular or isosceles trapezoid. The primary permanent magnet bilateral linear magnetic field modulation motor according to claim 1, wherein the permanent magnet (31) of the primary (3) is made of permanent magnet materials such as neodymium iron boron or ferrite, and the upper secondary (1), The modular armature teeth (33) of the lower secondary (2) and the primary (3) are all laminated by high-permeability silicon steel sheet materials. The primary permanent magnet double-sided linear magnetic field modulation motor according to claim 1, characterized in that: the number of pole pairs P _{w of the primary armature winding (321), the number of pole pairs P pm of the} permanent magnet (31), and the upper secondary salient pole tooth (11) Or the number n _{s of} the lower secondary salient pole teeth (21) satisfies the following relationship: n _s =P _w +P _pm . The primary permanent magnet bilateral linear magnetic field modulation motor according to claim 1, characterized in that: the primary (3) modular armature tooth (33) iron core is fixed by external mechanical parts to ensure uniform distribution in space, the primary (3) The primary armature winding (321) adopts distributed winding, which is single-layer or double-layer winding. The primary permanent magnet bilateral linear magnetic field modulation motor according to claim 1, characterized in that: the primary armature slot (32) of the primary (3) is in the form of a semi-closed slot or a closed slot; the modular armature of the primary (3) The teeth (33) present a centrally symmetrical structure in space. A low reluctance design method for a primary permanent magnet double-sided linear magnetic field modulation motor is characterized in that it includes the following design steps: Step 1: Connect the primary back-to-back of the primary permanent magnet linear motors of two single-sided structures, and form a whole through the same yoke core, and the top of each primary (3) tooth is surface-attached with a permanent magnet (31); Step 2: In order to ensure the normal operation of the motor, it is necessary to set the excitation of the permanent magnet (31). The excitation direction of the unilateral adjacent permanent magnet (31) of the primary (3) is opposite, corresponding to the excitation direction of the permanent magnet (31) on the tooth the same; Step 3: In order to make the magnetic field lines form an effective series connection between the upper secondary (1) and the lower secondary (2), to simplify the magnetic circuit and reduce the magnetic resistance, the upper secondary salient pole tooth (11) and the lower secondary The salient pole teeth (21) are arranged directly opposite, and the magnetic field lines do not pass through the primary yoke to form a loop. Therefore, the secondary yoke core is removed, and the primary (3) forms a modular armature tooth (33) structure; Step 4: Remove the space between the permanent magnets (31) on both sides of the primary (3), leave the permanent magnets (31) in the same direction on one side, and make the excitation directions of the permanent magnets (31) on both sides of the primary (3) be opposite; Step 5: Replace the removed permanent magnet (31) with an iron core material, and form an integral structure with the modular armature tooth (33); Step 6: Analyze the magnetic field of the upper air gap (4) and the lower air gap (5) according to the number of pole pairs of the permanent magnet (31) and the upper secondary salient pole teeth (11) or the lower secondary salient pole teeth (21) Harmonic situation, and arrange the primary armature winding (321) with the appropriate number of pole pairs in the primary armature slot (32).

Images