CN202076918U - Low positioning force high thrust linear switch magnetic flux permanent magnet motor - Google Patents

Abstract

The utility model discloses a linear plate type switch magnetic flux permanent magnet motor. The motor includes a secondary stator and a primary mover. The primary mover includes a U-shaped iron core with a U-shaped cross-section, a permanent magnet, a non-magnetic conductor interval, Magnetic bridge and primary three-phase winding; a non-magnetic gap with the same thickness is set between two adjacent U-shaped cores, the magnetic bridge is set on the top of the U-shaped core, and two U-shaped cores in the same phase Two permanent magnets with the same thickness and opposite directions of magnetization are installed between the magnetic bridge and the secondary stator. On the surface facing the primary mover, there is a pole that can be driven by a sine wave current controller for precise positioning control. And slot; there is an air gap between the U-shaped iron core of the primary mover and the secondary mover. The utility model is used in a direct-drive AC transmission system, and does not need an intermediate transmission structure and a speed change device. It can be used as a direct drive motor for the feed drive system of CNC machine tools, and can also be used in translational transmission systems with positioning functions.

Description

A low positioning force high thrust linear switch flux permanent magnet motor

technical field

The utility model is used in the fields of translational transmission or machine tool feed drive with positioning requirements, and relates to a novel linear flat switch magnetic flux permanent magnet motor, specifically a low positioning force high thrust linear switch magnetic flux permanent magnet motor. magnetic motor.

Background technique

At present, high-end CNC machine tools using linear motors as feed drive motors are becoming more and more technical hotspots in the industry. This is because the traditional "rotary servo motor + ball screw" feed method is limited in improving various performances, while the linear The motor has great potential in improving various performances. However, due to the existence of the edge effect of the linear motor, the uneven magnetic field during operation causes the disadvantage of large thrust fluctuations. Moreover, since the linear motor is directly connected to the processing tool, the disturbance and friction of the external load will be directly transmitted to the linear motor. This requires the feed drive system including linear motors to have higher dynamic performance and stability, and puts forward higher requirements for the design and manufacture of linear motors.

The sine wave linear permanent magnet motor has high power density and fast, precise and high control performance, making it the first choice for linear motors for feed drives. However, the number of permanent magnets placed on the long secondary stator is large, and the cost is high, which is not conducive to the popularization and application of linear motors. Therefore, manufacturing cheap switched reluctance linear motors has become one of the choices in this field. The defect of the switched reluctance linear motor is also obvious. The thrust fluctuates greatly during operation, and the mechanical noise has always been a problem that is difficult to solve. In recent years, doubly salient motors with permanent magnets have been well developed, especially the flux-switching permanent magnet motors have the advantages of permanent magnet synchronous motors and switched reluctance motors, and have attracted great attention from the industry.

Contents of the invention

The purpose of the utility model is to provide a linear plate type magnetic flux switching permanent magnet motor with simple structure, large thrust and low positioning force. The electric motor is used in a direct-drive AC drive system without the need for intermediate drive structures and speed changers. It can be used as a direct drive motor for the feed drive system of CNC machine tools, and can also be used in translational transmission systems with positioning functions.

The purpose of this utility model is achieved through the following technical solutions:

A linear plate type switched flux permanent magnet motor, characterized in that: the motor includes a secondary stator and a primary mover, the primary mover includes a U-shaped iron core with a U-shaped structure in cross section, a permanent magnet, a non-magnetic conductor interval, a guide Magnetic bridge and primary three-phase winding; between two adjacent U-shaped cores, there is a non-magnetic spacer with the same thickness, and the magnetic bridge is set on the top of the U-shaped core. Two permanent magnets with the same thickness and opposite directions of magnetization are installed between the magnetic bridges; the secondary stator is provided with poles and poles on the surface facing the primary mover that can be driven by a sine wave current for precise positioning control. Slot; there is an air gap between the U-shaped core of the primary mover and the secondary mover.

 其中，m为整数；

其中，n为整数，使得电机的出力大、定位力小、且使得该电机可用正弦波电流驱动的控制器来进行精密定位控制。  In the utility model, between the primary pitch τ _t and the secondary pole pitch τ _p , between the phase pitch ρ and the secondary pole pitch τ _p meet the following requirements:

Among them, m is an integer;

Wherein, n is an integer, so that the output force of the motor is large and the positioning force is small, and the motor can be controlled precisely by a controller driven by a sine wave current.

The U-shaped iron core is made of silicon steel sheets. The permanent magnet is made of neodymium iron boron material, and its magnetization direction makes the magnetic potential of the permanent magnet in the same phase be connected in series, and the magnetic flux of the adjacent phase is in the opposite direction. A set of identical poles and slots are evenly distributed on the secondary stator and face the air gap side.

The secondary stator can be processed from a whole piece of alloy with good magnetic permeability; the primary winding occupies two winding slots for each phase, and adopts a single-layer concentrated winding method.

In the utility model, the whole motor is a flat plate structure, the U-shaped iron core of the primary mover, the non-magnetic body interval and the three-phase winding are located under the mover, the tops of the two U-shaped iron cores in the same phase and the two ends of the magnetically conductive bridge Two permanent magnets with opposite directions of magnetization and the same thickness are placed between them. The side of the secondary stator opposite to the teeth of the primary mover is poles at equal intervals, and there is an air gap between the primary mover and the secondary stator.

Between the number of primary slots and the number of secondary poles, between the primary tooth pitch τ _t and the secondary pole pitch τ _p , and between the phase pitch ρ and the secondary pole pitch τ _p of the linear flat-plate switched flux permanent magnet motor With a definite quantitative relationship, the performance of the motor is optimized, and it is suitable for low-speed, high-thrust precision transmission systems.

The permanent magnet of the linear motor is made of neodymium iron boron material, and its magnetization direction makes the magnetic potential of the permanent magnet in the same phase connected in series, and the permanent magnet flux of adjacent phases is magnetized and placed in the opposite direction.

The beneficial effects of the utility model are as follows:

1. Directly connected to the drive, no intermediate transmission structure is required, which reduces intermediate mechanical losses and improves system reliability and stability.

2. Compared with the linear permanent magnet synchronous motor for the same purpose, it has a comparable thrust density and lower manufacturing cost; compared with the linear switched reluctance motor for the same purpose, it has a higher thrust density and comparable manufacturing cost.

3. The optimized design of the primary tooth/slot and secondary pole/slot reduces the positioning force, reduces the harmonics of the magnetic field, and improves the positioning accuracy of the motor.

4. The permanent magnets and windings are placed on the primary, which is conducive to heat dissipation and cooling, and improves the output and service life of the motor, and the placement and processing of the permanent magnets are simple.

5. The secondary is a single magnetic conductor pole/slot structure, which is simple and reliable in structure and low in processing cost.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a longitudinal sectional view of the motor and a schematic diagram of dimensions.

Detailed ways

A novel linear plate type switched flux permanent magnet motor described in the utility model, comprising a primary iron core 21, a permanent magnet 22, a magnetically conductive bridge 24, a non-magnetically conductive spacer 23, a three-phase winding 3, and a secondary mover 1 and air gap 4, as shown in Figure 1. The whole motor has a flat plate structure, and two permanent magnets with opposite magnetization directions are placed between two U-shaped iron cores in the same phase and the two ends of the magnetic permeable bridge to form a closed magnetic circuit. The primary three-phase winding is embedded in the U-shaped slot of the primary iron core in the form of single-layer concentrated winding, and the air gap is located between the primary and secondary of the motor. The primary iron core can be made of silicon steel sheets, and the secondary stator air gap side is a U-shaped pole and slot structure with the same interval, which can be processed from a whole piece of alloy with better magnetic conductivity.

其中，n为整数，图2是电机的纵向截面图及尺寸标注示意图。其中，τ _t为初级齿距，τ _p为次级极距、ρ为相间距。在图2中n=6；τ _p为次级极距，一个次级极距的长度相当于该电机的360电角度，即该电机的一个次级极相当于永磁同步电机的一对极。按照分数槽原理，如果初级槽数为6，则次级极数可选为1、5、7、11、13、17、19、23……。为得到较大的推力密度和较低的同步速度，该直线电机应采用少槽多极结构，图1所示电机为6槽/17极电机。工作速度范围由槽/极数和极距来决定，在实际应用中可根据实际要求来选择电机的槽/极数和次级的极距。 In order to meet the requirement that the three-phase windings have a mutual difference of 120 electrical degrees, the spatial distance of each phase winding of the primary mover is

Wherein, n is an integer, and Fig. 2 is a longitudinal sectional view of the motor and a schematic diagram of dimensions. Among them, τ _t is the primary tooth pitch, τ _p is the secondary pole pitch, and ρ is the phase pitch. In Figure 2, n=6; τ _p is the secondary pole pitch, the length of a secondary pole pitch is equivalent to 360 electrical angles of the motor, that is, a secondary pole of the motor is equivalent to a pair of poles of the permanent magnet synchronous motor . According to the principle of fractional slots, if the number of primary slots is 6, the number of secondary poles can be 1, 5, 7, 11, 13, 17, 19, 23.... In order to obtain greater thrust density and lower synchronous speed, the linear motor should adopt a multi-pole structure with fewer slots. The motor shown in Figure 1 is a 6-slot/17-pole motor. The working speed range is determined by the number of slots/poles and the pole distance. In practical applications, the number of slots/poles and the secondary pole distance of the motor can be selected according to actual requirements.

 其中，m为整数，在图1所示电机中m=1。 In order to minimize the positioning force of the linear motor, the principle of permeance modulation is used to optimize the tooth pitch of the primary mover. The relationship between the primary gear pitch τ _t and the secondary pole pitch τ _p of the motor shown in Fig. 1 satisfies the following relationship:

Among them, m is an integer, and m=1 in the motor shown in Fig. 1 .

When the linear plate type switched flux permanent magnet motor satisfying the above dimensional relationship is driven and controlled, an inverter with a sine wave current control method can be used for driving and controlling. The operating principle of the linear motor can be equivalent to the working principle of the permanent magnet synchronous linear motor. It can be seen from the above description that the pole pitch of the linear motor is extremely small, so higher positioning accuracy can be achieved during control.

Claims (3)

1. A linear flat plate type switch magnetic flux permanent magnet motor is characterized in that: the motor comprises a secondary stator (1) and a primary rotor (2), wherein the primary rotor (2) comprises a U-shaped iron core (21) with a U-shaped section, a permanent magnet (22), a non-magnetic-conductive interval (23), a magnetic conductive bridge (24) and a primary three-phase winding (3); a non-magnetic conductive magnet interval (23) with the same thickness is arranged between two adjacent U-shaped iron cores (21), a magnetic conductive bridge (24) is arranged at the top of the U-shaped iron core (21), and two permanent magnets (22) with the same thickness and opposite magnetizing directions are arranged between two U-shaped iron cores (2.1) of the same phase and the magnetic conductive bridge (24); the secondary stator (1) is provided with a pole (11) and a groove (12) which can be driven by sine wave current to carry out precise positioning control by a controller on the surface facing the primary rotor (2); an air gap (4) is arranged between the U-shaped iron core (21) of the primary mover (2) and the secondary mover (1).

2. The linear plate switch flux permanent magnet motor of claim 1, wherein: primary pitchτ _tDistance from secondary poleτ _pSpacing between phases, p and secondary pole pitchτ _pThe following requirements are met:

wherein m is an integer;

wherein n is an integer.

3. The linear plate switch flux permanent magnet motor of claim 1, wherein: a group of poles (11) and slots (12) with the same structure are uniformly distributed on the secondary stator (1) and face to the side of the air gap (4).

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