CN103066719B - A kind of magneticfocusing stator permanent magnetic type vernier motor - Google Patents

Abstract

The present invention discloses a kind of magneticfocusing stator permanent magnetic type vernier motor, rotor is positioned at stator exterior, between rotor and stator, there is air gap, stator has stator tooth and stator slot in the one end near air gap, each stator tooth increment has empty tooth and empty groove, each stator tooth increment two ends are along the circumferential direction empty tooth, more than empty groove number one of virtual number of teeth; An empty groove is embedded with a permanent magnet unit be made up of one piece of radial magnetizing permanent magnetism body and two pieces of cutting orientation magnetizing permanent magnets, one piece of cutting orientation magnetizing permanent magnet is all closely pasted in the both sides of radial magnetizing permanent magnetism body, the magnetizing direction of two pieces of cutting orientation magnetizing permanent magnets in an empty groove is relative, and the polarity of each radial magnetizing permanent magnetism body is consistent; Owing to being provided with empty tooth, therefore can reducing the consumption of permanent magnet, reduce costs; By cooperatively interacting between permanent magnet, teeth portion leakage flux be can effectively reduce, Driving Torque and power density improved.

Description

A magnetism-concentrating stator permanent magnet vernier motor

technical field

The invention relates to a motor or generator with high power density, which belongs to the field of permanent magnet motors.

Background technique

The vernier motor has the characteristics of low speed and high torque, so it has good applications in fields such as rail transit, ship propulsion, food processing and electric vehicles. Since the rotor permanent magnet motor puts the permanent magnet on the rotor, it brings certain difficulties to the cooling of the motor, and if the temperature is too high, it will affect the stable operation of the motor, especially when the temperature exceeds the Curie temperature of the permanent magnet. It will cause the permanent magnets to lose their magnetism permanently, making the motor malfunction. Stator permanent magnet motors place permanent magnets on the stator, and the rotor has no windings and permanent magnets.

The document IEEETRANSACTIONSONMAGNETICS, 47(10):4219-4222, 2011 (Design and Analysis of Linear Stator Permanent Magnet Vernier Machines) introduces a linear stator permanent magnet vernier motor, the permanent magnet is placed at the stator tooth end, but the stator permanent magnet vernier motor is at the stator tooth end , There is a relatively serious magnetic flux leakage in the rotor tooth end and air gap, which seriously affects the effective magnetic flux contact area of the motor, reduces the effective air gap flux density of the motor, and greatly reduces the back EMF induced in the winding, so that the power density and Compared with the rotor permanent magnet motor of the same volume, it is relatively low, and the utilization rate of the motor is low.

Contents of the invention

The purpose of the present invention is to propose a magnetism-concentrating type vernier motor in order to solve the problems of serious flux leakage, small magnetic density in the air gap, small counter electromotive force in the stator winding, and excessive permanent magnet consumption in the existing stator permanent magnet vernier motor. Stator permanent magnet type vernier motor.

The technical scheme adopted in the present invention is: the rotor is located outside the stator, there is an air gap between the rotor and the stator, the stator has stator teeth and stator slots at one end close to the air gap, and each stator tooth end has virtual teeth and virtual slots, each Both ends of a stator tooth tooth end along the circumferential direction are virtual teeth, and the number of virtual teeth is one more than the number of virtual slots; a virtual slot is embedded with a permanent magnet composed of a radial magnetization and two tangential magnetization permanent magnets. The two sides of the radial magnetization permanent magnet are closely attached to a tangential magnetization permanent magnet, and the magnetization direction of the two tangential magnetization permanent magnets in a virtual slot is opposite, and each radial magnetization The polarity of the permanent magnets is consistent.

Since the present invention is provided with virtual teeth, it can reduce the amount of permanent magnets, thereby reducing the manufacturing cost of the motor; the magnetic flux in the present invention is mainly provided by radially magnetized permanent magnets, and the magnetic field lines start from the permanent magnets and pass through the air gap, The rotor teeth and the air gap return to the permanent magnets to form a closed loop; through the mutual cooperation between the permanent magnets, the leakage flux of the teeth can be effectively reduced, the magnetic density in the magnetic circuit can be effectively increased, and the air gap magnetic flux density can be increased. The back electromotive force in the winding can be effectively increased to increase the output torque and power density. The motor structure of the present invention can be used not only as a rotary motor, but also as a linear motor.

Description of drawings

The present invention is only described below in conjunction with the accompanying drawings and specific embodiments of the five-phase motor:

Fig. 1 is the radial structure schematic diagram of the five-phase magnetic gathering type stator permanent magnet vernier motor of the present invention;

Fig. 2 is the enlarged expanded view of the rotor 2 structure in Fig. 1;

Fig. 3 is an enlarged view of a partial structure of the stator 1 in Fig. 1;

Fig. 4 is an enlarged view of the structure of a stator tooth 12 in Fig. 1;

Fig. 5 is the comparison diagram of back EMF waveform when the traditional five-phase stator permanent magnet vernier motor and the motor winding of the present invention are concentrated windings;

Fig. 6 is a comparison schematic diagram of back EMF waveform when the traditional five-phase stator permanent magnet vernier motor and the motor winding of the present invention are distributed windings;

Fig. 7 is a comparative schematic diagram of the back EMF waveform when the motor winding of the present invention is a concentrated winding and a distributed winding;

Fig. 8 is the connection mode in which the A-phase winding of the motor of the present invention is a concentrated winding;

Fig. 9 is the connection mode in which the phase A winding of the motor of the present invention is a distributed winding;

Figure 10 is a part of the magnetic density diagram of the traditional five-phase stator permanent magnet vernier motor;

Fig. 11 is a partial flux density diagram of the motor of the present invention;

In the figure: 1. stator; 2. rotor; 12. stator tooth; 14. stator slot; 19. slot; 21. rotor tooth; 22. rotor yoke; 31, 32, 33. permanent magnet; 101. virtual slot; 102 . Empty teeth; 300. Permanent magnet unit.

detailed description

Referring to FIG. 1 , the present invention comprises a coaxial stator 1 and a rotor 2 , and the rotor 2 is located outside the stator 1 . The center of the stator 1 has a slot 19 for placing the rotating shaft. There is an air gap between the rotor 2 and the stator 1, and the thickness of the air gap is determined according to the size and requirements of the motor. The stator 1 is composed of stator teeth 12 and stator slots 14 , the stator slots 14 are used to place the windings, and the tooth ends of the stator teeth 12 are embedded with permanent magnet units 300 .

The specific structure and proportional relationship of the rotor 2 are shown in FIG. 2 . The rotor 2 is composed of rotor teeth 21 and a rotor yoke 22 . The tooth height of the rotor teeth 21 and the rotor yoke 22 can be optimized as required. The end of the rotor tooth 21 facing the air gap has a trapezoidal structure, and the ratio K ₁ of the tooth width S ₁ of the rotor tooth 21 near the air gap to the tooth pitch T _p of the rotor tooth 21 satisfies the following relationship: K ₁ ( S ₁ /T _p )=0.2~0.5; the ratio of the tooth width S ₁ of the rotor tooth 21 close to the air gap side to the tooth width S ₂ of the rotor tooth 21 close to the rotor yoke 22 satisfies the following relationship: K ₂ ( S ₁ /S ₂ )=0.1 ~0.9, the specific size is determined by the motor itself; the materials of the rotor teeth 21 and the rotor yoke 22 are made of laminated silicon steel sheets or processed with magnetically permeable materials. )

As shown in FIGS. 1 , 3 and 4 , a permanent magnet unit 300 is embedded in the tooth end slot of the stator 1 , and the permanent magnet unit 300 is composed of three permanent magnets 31 , 32 and 33 . The stator 1 is also slotted at the end close to the air gap to form a cogged structure, that is, stator teeth 12 and stator slots 14 . The stator slot 14 can adopt various slot types, which can be selected according to specific needs. The main features of the stator teeth 12 are concentrated at their tooth ends. As shown in Fig. 3, assuming that the number of teeth of the motor is N , N = 1, 2, 3... n , grooves are slotted along the tooth end of each stator tooth 12 to form virtual teeth 102 and virtual slots 101, the number of virtual teeth than the number of virtual slots one more, namely = +1, both ends of the tooth end of each stator tooth 12 along the circumferential direction are virtual teeth 102 . The radian angle of each virtual slot 101 is , the radian angle of each imaginary tooth 102 is , the radian angle occupied by the imaginary groove 101 and the imaginary tooth 102 is K, K ( / )=0.8~1.1.

A permanent magnet unit 300 is embedded in a dummy slot 101, as shown in FIG. The volume of the radial magnetization permanent magnet 32 is greater than the volume of a single tangential magnetization permanent magnet 31,33, the radial magnetization permanent magnet 32 is located in the middle of the virtual slot 101, and the two sides of the radial magnetization permanent magnet 32 are respectively closely spaced. A piece of tangential magnetization permanent magnet 31, 33 is pasted, the magnetization directions of the two tangential magnetization permanent magnets 31, 33 in one dummy slot 101 are opposite, and the polarity of each radial magnetization permanent magnet 32 is consistent. The direction of magnetization is shown by the arrow in Figure 4. The tangentially magnetized permanent magnets 31 and 33 play the role of magnetism gathering.

The height of each permanent magnet 31, 32, 33 along the radial direction is equal. The percentage of the arc angle occupied by the radially magnetized permanent magnet 32 in the arc angle occupied by the entire permanent magnet unit 300 is , =0.6~0.9. The percentage of the radian angle occupied by a single tangentially magnetized permanent magnet 31 or 33 to the arc angle occupied by the entire permanent magnet unit 300 is , =0.05~0.2.

The magnetic flux is mainly provided by the radially magnetized permanent magnet 32. The magnetic force line starts from the permanent magnet unit 300, passes through the air gap, faces the rotor tooth 21, and returns to the permanent magnet unit 300 from the other rotor tooth 21 through the air gap to form a closed loop. Circuit; tangentially magnetized permanent magnets 31, 33 play a role in reducing magnetic flux leakage.

The permanent magnet unit 300 produces the number of pole pairs p of the magnetic field distribution and the number of radially magnetized permanent magnets 32 and number of rotor teeth 21 Coordination is related, the difference between the absolute value of the two is the pole logarithm p of the magnetic field distribution, which is expressed by the formula: . If the number of radially magnetized permanent magnets is 32 50, the number of rotor teeth is 21 is 59, then the number of pole pairs p of the magnetic field generated by the permanent magnet is 9; if remain unchanged, the number of rotor teeth is 21 is 41, and the number of pole pairs p of the magnetic field generated by the permanent magnet is also 9.

The motor of the present invention can be designed as a single-phase or multi-phase motor according to needs, and each phase winding can adopt a concentrated or distributed winding. It should be pointed out that if other conditions are not changed, only the connection mode of the winding is changed. The generated counter electromotive force is much larger than the concentrated winding. In addition, for distributed windings, the more pole pairs, the smaller the back electromotive force induced in the windings. Concentrated windings are not obvious to this situation.

Fig. 5 is a back EMF waveform diagram when the windings of the traditional five-phase stator permanent magnet vernier motor (A1 waveform line) and the motor of the present invention (A2 waveform line) are concentrated windings. It can be seen that when the size is the same, the amplitude of the back EMF of the traditional five-phase stator permanent magnet vernier motor is about 60V, while the amplitude of the back EMF of the motor of the present invention exceeds 130V.

Fig. 6 is the back EMF waveform diagram when the windings of the traditional five-phase stator permanent magnet vernier motor (A waveform line) and the motor of the present invention (B waveform line) are distributed windings. The back EMF amplitude of the traditional five-phase ordinary stator permanent magnet vernier motor is about 240V, while the back EMF amplitude of the motor of the present invention can exceed 500V.

Fig. 7 is the back EMF waveform diagram when the winding of the motor of the present invention is a distributed winding (B1 waveform line) and a concentrated winding (B2 waveform line). It can be seen that without changing other conditions, only changing the winding connection mode, the distribution winding The back EMF is much larger than that of the concentrated winding.

Fig. 8 and Fig. 9 show the connection mode of the A-phase winding of the motor in the present invention as concentrated winding and distributed winding. A+ means in, A- means out. 51, 52, 54, and 55 represent end windings, respectively. Comparing the magnetic force lines 41 in FIG. 10 and the magnetic force lines 42 in FIG. 11 , it can be seen that the motor of the present invention can effectively reduce magnetic flux leakage and increase the power density of the motor.

Claims (3)

1. A vernier motor with magnetism-concentrating stator and permanent magnet type. The rotor (2) is located outside the stator (1), and there is an air gap between the rotor (2) and the stator (1). The feature is that the stator (1) is close to There are stator teeth (12) and stator slots (14) at one end of the air gap, windings are placed in the stator slots (14), each stator tooth (12) has virtual teeth (102) and virtual slots (101) at the tooth end, each Both ends of the stator teeth (12) along the circumferential direction are virtual teeth (102), and the number of virtual teeth is one more than the number of virtual slots; a virtual slot (101) is embedded with a radially magnetized permanent magnet (32 ) and a permanent magnet unit (300) composed of two tangentially magnetized permanent magnets (31, 33), the volume of the radially magnetized permanent magnet (32) is larger than the volume of a single tangentially magnetized permanent magnet (31, 33) , both sides of the radial magnetization permanent magnet (32) are closely attached to a tangential magnetization permanent magnet (31, 33), and two tangential magnetization permanent magnets (31, 33) in a virtual slot (101) ), the magnetization direction of each radially magnetized permanent magnet (32) is consistent, and one radially magnetized permanent magnet (32) and two tangentially magnetized permanent magnets (31, 33) are along the radial direction are equal in height; The rotor (2) is composed of rotor teeth (21) and rotor yoke (22). The end of the rotor teeth (21) facing the air gap has a trapezoidal structure, and the tooth width of the rotor teeth (21) near the air gap is the same as that of the rotor teeth (21). ) tooth pitch ratio is 0.2~0.5, the ratio of the tooth width of the rotor tooth (21) near the air gap side to the tooth width of the rotor tooth (21) near the rotor yoke (22) is 0.1~0.9; The permanent magnet unit (300) produces the number of pole pairs of the magnetic field distribution , is the number of radially magnetized permanent magnets (32), is the number of rotor teeth (21); The magnetic flux is provided by the radially magnetized permanent magnet (32), and the magnetic force line starts from the permanent magnet unit (300), passes through the air gap, faces the rotor tooth (21), and returns to the permanent magnet from another rotor tooth (21) through the air gap. A closed loop is formed in the magnet unit (300). 2. A magnetism-concentrating stator permanent-magnet vernier motor according to claim 1, characterized in that: the arc angle occupied by the radially magnetized permanent magnet (32) accounts for half of the arc angle occupied by the permanent magnet unit (300) The ratio is 0.6-0.9, and the ratio of the arc angle occupied by a single tangentially magnetized permanent magnet (31, 33) to the arc angle occupied by the permanent magnet unit (300) is 0.05-0.2. 3. A magnetism-concentrating stator permanent magnet vernier motor according to claim 1, characterized in that: the ratio of the arc angle occupied by the virtual slot (101) to the arc angle occupied by the virtual tooth (102) is 0.8~1.1 .