CN111769713A - Ironless Cylindrical Permanent Magnet Synchronous Linear Motor - Google Patents

Abstract

The invention relates to an ironless cylindrical permanent magnet synchronous linear motor. The motor consists of a stator and a mover. An axial magnetizing magnetic ring and a radial magnetizing magnetic ring are arranged on the core rod in the stator. The ring is made of NdFeB permanent magnet material, the magnetization angle of adjacent magnetic ring units changes by 90 degrees in turn, and the magnetic ring unit structure has a certain radian; the armature winding in the mover is a double-layer structure, which is composed of three-phase cakes. It is composed of an ironless double-layer coil. In the present invention, the shape of the magnetic ring is a drum, and the generated air gap magnetic field can be homogenized, thereby suppressing the content and amplitude of high-order harmonics of the air gap magnetic field, and can effectively improve the coreless cylindrical permanent magnet synchronization. The amplitude and sine type of the air gap magnetic field of the linear motor can significantly improve the positioning accuracy of the motor; secondly, the double-layer winding can be used to improve the winding coefficient, which can effectively overcome the low thrust of the existing ironless cylindrical permanent magnet synchronous linear motor. The disadvantage is that the average thrust density of the motor is increased.

Description

Ironless Cylindrical Permanent Magnet Synchronous Linear Motor

technical field

The invention belongs to the technical field of electromechanical engineering, and relates to an ironless cylindrical permanent magnet synchronous linear motor.

Background technique

Permanent magnet synchronous linear motors have the advantages of fast response, high acceleration, and high positioning accuracy, and are widely used in precision positioning systems. Permanent magnet synchronous linear motor can be divided into iron core permanent magnet synchronous linear motor and ironless permanent magnet synchronous linear motor, iron core permanent magnet synchronous linear motor will produce cogging during operation due to the existence of cogging effect. Force and cogging force will have adverse effects on the positioning of the motion platform driven by the motor, that is, thrust fluctuations will occur. In precision positioning, it is hoped that the smaller the cogging force, the better, and the ironless permanent magnet synchronous linear motor can overcome the shortcomings of the cogging force, so the ironless permanent magnet synchronous linear motor is often used as the drive of the precision positioning system. The flat-type permanent magnet synchronous linear motor will also produce thrust fluctuations during the positioning process due to the adverse effect of its end effect, which is not conducive to its precise positioning requirements, while the cylindrical permanent magnet synchronous linear motor can overcome the end effect. influence on motor operation. The ironless permanent magnet synchronous linear motor does not have the magnetization effect of the winding core, resulting in a weak air gap magnetic field, and its average thrust density is smaller than that of the same iron core permanent magnet synchronous linear motor. In practical high thrust applications will cause inconvenience. Therefore, it is necessary to overcome the shortcomings of the existing ironless cylindrical permanent magnet synchronous linear motor with low thrust fluctuation and low average thrust density.

For the thrust fluctuation problem, domestic and foreign researchers have done a lot of work from the ontology structure. Mainly optimize the motor topology, such as adopting inclined slot, inclined pole and other methods to weaken the cogging effect of the motor and reduce the thrust fluctuation. However, the methods such as inclined slot and inclined pole mainly weaken the thrust fluctuation caused by the cogging effect, and have little improvement on the waveform of the air gap magnetic flux density of the motor. In response to the problem of low average thrust density, domestic and foreign researchers have done a lot of work by changing the structure of coil windings, mainly using distributed windings instead of centralized windings to improve the winding coefficient and indirectly improve the average thrust density of the motor. Although this method can greatly improve the winding coefficient of the coil, the ends of the coils overlap each other and take up more space. The complex distributed winding structure is inconvenient for coil winding and primary production and installation.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an ironless cylindrical permanent magnet synchronous linear motor to overcome the problems of large thrust fluctuation and small average thrust density of the existing permanent magnet synchronous linear motor.

In order to achieve the purpose of the present invention, the technical solution adopted in the present invention is: an ironless cylindrical permanent magnet synchronous linear motor, comprising a stator and a mover, the stator and the mover are arranged coaxially, and the stator It includes a mandrel, which is characterized in that: the mandrel is sleeved with a plurality of drum-shaped magnetic rings, and the magnetic rings are divided into two types: radially magnetized magnetic rings and axially magnetized magnetic rings, which are arranged alternately and The magnetization angle of the magnetic ring is changed by 90 degrees in turn;

The mover includes an armature winding, and the armature winding is composed of three-phase pie-shaped ironless coils, and the three-phase pie-shaped ironless coils are closely arranged to form a double-layer form, and the outer winding and the inner winding are formed. The outer coils and the inner coils are arranged as coaxial lines, and any single-layer winding is a concentrated winding.

The middle diameter of the above-mentioned magnetic ring is 0.5-1 mm larger than the diameters of both ends, and the middle diameter is 10-12 mm.

The total axial length of the radially magnetized magnetic ring and the axially magnetized magnetic ring on the stator is greater than the axial length of the armature winding on the motor mover.

Compared with the prior art, the advantages of the present invention are:

1. The coreless cylindrical permanent magnet synchronous linear motor of the present invention designs the axial outer surface of the magnetic ring into an arc shape, and through the design of the arc structure, the distribution of the magnetic field generated in the air gap space is uniformized, and the air The harmonics of the gap magnetic field are effectively suppressed, and the air gap magnetic field distribution tends to be more sinusoidal, which can effectively reduce the impact of thrust fluctuations on the ironless cylindrical permanent magnet synchronous linear motor, and improve the ironless cylindrical permanent magnet synchronous linear motor. The positioning accuracy of the motor.

2. The armature winding of the ironless cylindrical permanent magnet synchronous linear motor adopts a double-layer three-phase pie-shaped ironless coil. Through the design of the three-phase pie-shaped ironless double-layer coil, the winding coefficient can be improved. , the thrust of the motor can be increased, and the shortcoming of the small thrust of the ironless cylindrical permanent magnet synchronous linear motor can be overcome.

3. The coreless cylindrical permanent magnet synchronous linear motor of the present invention adopts the Halbach magnetic pole array, wherein the axial magnetizing magnetic ring is along the left and right directions of the axis, and the radial magnetizing magnetic ring radiates outward and inward along the axis, which can Get higher air-gap magnetic field strength. At the same time, the amount of permanent magnets used in the Halbach magnetic pole array used in the present invention is half less than that of the upper and lower arrangement under the same magnetic field strengthening effect, which can save the amount of permanent magnets.

Description of drawings

1 is a schematic cross-sectional view of an ironless cylindrical permanent magnet synchronous linear motor according to the present invention;

2 is a sectional view of the drum-shaped magnetic ring structure of the ironless cylindrical permanent magnet synchronous linear motor of the present invention;

3 is a schematic diagram of the distribution of the magnetic field lines of the Halbach permanent magnet array of the ironless cylindrical permanent magnet synchronous linear motor according to the present invention;

4 is a schematic diagram of a three-phase cake-shaped ironless double-layer coil of an ironless cylindrical permanent magnet synchronous linear motor according to the present invention;

The reference numerals are explained as follows:

1- Mandrel, 2- Radial magnetizing ring, 3- Axial magnetizing ring, 4- Armature winding, 201- Radiation magnetizing outward along the axis, 202- Radiation magnetizing inward along the axis , 301-magnetization to the left along the axial direction, 302-magnetization to the right along the axial direction, 401-armature winding A+, 402-armature winding A-, 403-armature winding B+, 404-armature winding B-, 405-armature winding C+, 406-armature winding C-.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

As shown in FIG. 1 , the ironless cylindrical permanent magnet synchronous linear motor of the present invention includes a stator and a mover, the stator and the mover are arranged coaxially, and the stator includes a mandrel 1 , which is located on the mandrel. 1. The upper sleeve is provided with a plurality of drum-shaped magnetic rings, and the magnetic rings are divided into two types: radially magnetized magnetic rings 2 and axially magnetized magnetic rings 3. The magnetization directions of the radially magnetized magnetic rings 2 include Radiating outward along the axis and radiating inward along the axis, the magnetization direction of the axially magnetized magnetic ring 3 includes leftward along the axis and rightward along the axial direction, the two magnetic rings are arranged alternately and the The magnetization angle is changed by 90 degrees in turn. The mover includes an armature winding 4, and the armature winding 4 is composed of three-phase pie-shaped ironless coils. The three-phase pie-shaped ironless coils are closely arranged to form a double-layer form. The windings are closely connected without leaving gaps, the outer coil and the inner coil are arranged as coaxial lines, and any single-layer winding is a concentrated winding. The middle diameter of the magnetic ring is 0.5-1 mm larger than the diameters of both ends, and the middle diameter is 10-12 mm. The total axial length of the radial magnetizing ring 2 and the axial magnetizing ring 3 on the stator is greater than the axial length of the armature winding 4 on the motor mover, and the armature winding 4 on the motor mover runs along the Reciprocating motion along the length of the axis.

As shown in Figure 2, the drum-shaped radially magnetized magnetic rings 2 and the axially magnetized magnetic rings 3 are closely arranged, both of which are made of NdFeB permanent magnet materials. Magnetization 201, magnetization 301 to the left along the axis, radiation magnetization 202 along the axis inward, magnetization 302 to the right along the axis, it can be found from the radial section that the magnetization angle of adjacent permanent magnet units in the present invention changes by 90% degree, with "radiation magnetization 201 along the axis outward", "magnetization left along the axis 301", "radiation magnetization 202 inward along the axis", "magnetization 302 right along the axis" as one Magnetization cycle.

As shown in Figure 3, the principle of the Halbach magnetic pole array enhancing the air gap magnetic field is shown. The arrangement of the permanent magnet array can not only increase the magnetic field between the air gaps, but also reduce the magnetic flux leakage at the core rod, which can improve the utilization rate of the magnetic ring. And the Halbach magnetic pole array of the magnetic ring structure achieves the same magnetic field strengthening effect, and the amount of permanent magnets is half less than that of the upper and lower arrangement, which can save the amount of permanent magnets.

As shown in Figure 4, it is a three-phase pie-shaped ironless double-layer coil, which consists of armature winding A+401, armature winding A-402, armature winding B+403, armature winding B-404, armature winding Composed of C+405 and armature winding C-406, the three-phase windings are closely arranged in turn to form inner and outer double-layer windings, and the single-layer windings are arranged in a concentrated form, which improves the winding coefficient and can overcome the ironless cylindrical permanent magnet synchronous straight line. The disadvantage of small motor thrust. The three-phase pie-shaped ironless double-layer coil is connected to the guide rail through the skeleton. The excitation magnetic field generated by the permanent magnet interacts with the three-phase current to generate electromagnetic thrust, which can then reciprocate along the guide rail under the action of the power supply and control system. At the same time, the armature reaction magnetic field generated by the three-phase pie-shaped ironless double-layer coil is weak, which hardly affects the excitation magnetic field generated by the magnetic ring, so the ironless cylindrical permanent magnet synchronous linear motor is running, suspending and During the off period, the air-gap magnetic field can be considered to be constant, that is, the excitation magnetic field generated by the magnetic ring.

The above description of the embodiments is for better understanding of the present invention, and those skilled in the art can easily make slight modifications to the magnetic rings in the above embodiments, and apply the principles described in the above embodiments to other embodiments middle. Therefore, the present invention is not limited to the magnetic ring structure proposed in the above-mentioned embodiments, and minor modifications to the magnetic ring proposed by the present invention should be within the protection scope of the present invention.

Claims (3)

1. Synchronous linear electric motor of no iron core drum type permanent magnetism, including stator and active cell, the stator with the active cell coaxial setting, including plug (1), its characterized in that on the stator: the magnetic core comprises a core rod (1), wherein a plurality of drum-shaped magnetic rings are sleeved on the core rod (1), the magnetic rings are divided into a radial magnetizing magnetic ring (2) and an axial magnetizing magnetic ring (3), the radial magnetizing magnetic rings and the axial magnetizing magnetic rings are arranged at intervals, and the magnetizing angles of the magnetic rings are sequentially changed by 90 degrees;

the rotor comprises an armature winding (4), the armature winding (4) is composed of three-phase cake-shaped coreless coils, the three-phase cake-shaped coreless coils are tightly arranged to form a double-layer form, the outer-layer winding and the inner-layer winding are tightly connected without leaving a gap, the outer-layer coil and the inner-layer coil are arranged to be a coaxial line, and any single-layer winding is a concentrated winding.

2. The coreless, cylindrical, permanent magnet synchronous linear motor of claim 1, wherein: the diameter of the middle of the magnetic ring is 0.5-1 mm larger than the diameters of the two ends, and the diameter of the middle is 10-12 mm.

3. The coreless cylindrical permanent magnet synchronous linear motor according to claim 1 or 2, wherein: the axial total length of the radial magnetizing magnetic ring (2) and the axial magnetizing magnetic ring (3) on the stator is larger than the axial length of the armature winding (4) on the rotor of the motor.

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