Axial hybrid excitation doubly salient linear motor

Abstract

The invention discloses an axial hybrid excitation doubly salient linear motor which comprises a primary, a secondary, an air gap between the primary and the secondary, permanent magnets, a primary pole and a secondary pole which adopt salient pole structures, an excitation winding and a three-phase armature winding are wound on primary teeth, the tooth pitch of the secondary teeth is larger than that of the primary teeth, the permanent magnets and the secondary pole are equal in length, and the length of the secondary pole can be larger than that of the primary. Magnetic fields generated by the permanent magnets and the electro-magnetic field form a main magnetic field of the motor. Exciting winding coils are wound on the primary teeth, and magnetic flux paths of all phases are the same. When the axial hybrid excitation doubly salient linear motor works, output torque pulsation can be reduced, the motor is novel in structure, reliable in performance and easy to control, and the axial hybrid excitation doubly salient linear motor is suitable for medium and small power generation or electric occasions such as the packaging industry, the numerical control machine tool field and a cordless elevator as a traditional radial linear motor. Therefore, the axial hybrid excitation doubly salient linear motor has a great application market.

Description

Technical Field

[0001] The invention belongs to the field of double-salient-pole motor structures, relates to a three-phase axial hybrid excitation double-salient-pole linear motor, and belongs to the field of motor body design. Background Art

[0002] The double-salient-pole motor structure is increasingly used in aerospace, shipbuilding, green energy and other fields. The stator and rotor of the double-salient-pole motor are both salient-pole slot structures, and the stator armature winding is a centralized winding. Among them, the excitation winding is installed in the stator slot, which is also a centralized winding. The windings on the stator teeth opposite to each other in space are connected in series to form one phase. There is no winding on the rotor. It has a simple structure and reliable operation, which is suitable for high-speed operation and harsh working environments.

[0003] Linear motors have now entered the stage of independent application. The application of various types of linear motors has been rapidly promoted, such as steel pipe conveyors, coal conveyors, cranes, air compressors, electric doors and windows, electric textile machines, etc. They can also be used to drive maglev trains and other occasions. Linear motors can generate linear motion without the need for intermediate conversion mechanisms. They have a simple structure, improve dynamic response performance and positioning accuracy, save costs, and make production and maintenance easier. Power transmission is generated in the air gap, and there is no other friction except the linear motor guide rail, which reduces the wear of transmission parts and greatly reduces mechanical loss and friction noise. The linear motor has a wide operating speed range and eliminates the intermediate links that affect the accuracy. The accuracy of its system depends on the position detection element. The appropriate feedback device can make it accurate to microns in specific applications. By adjusting the voltage or frequency, or changing the secondary material, different speeds and electromagnetic forces can be obtained, which is suitable for low-speed reciprocating operation occasions and easy to adjust and control. In addition, linear motors also have advantages at high speeds. The primary core of the linear motor can be sealed with epoxy resin, which has good corrosion and moisture resistance and can be used in harsh environments. Linear motors generate a lot of heat when working under high load and high acceleration conditions. However, due to their structural characteristics, the heat dissipation area is relatively small and the heat is not easy to dissipate. If the heat cannot be dissipated in a timely and effective manner, the motor temperature will rise, affecting the performance and life of the motor.

[0004] Compared with traditional radial motors, axial motors have smaller axial dimensions and can be used in places with limited space, which can effectively save installation space, such as the hub motors of electric vehicles and the direct drive systems of wind turbines. Under the same volume and weight, axial motors can output higher power and torque, so the axial motor structure has advantages in application scenarios with high requirements for dynamic performance. The air gap magnetic field distribution of the axial motor is more reasonable, the flux path is short, and the magnetic resistance is small, so the energy conversion efficiency is higher, which helps to reduce energy consumption and improve the endurance or operating efficiency of the equipment. The heat dissipation area of ​​the axial motor structure is relatively large, which is conducive to heat dissipation and can more effectively dissipate the heat generated during the operation of the motor, thereby ensuring the stable operation of the motor.

[0005] To achieve the same magnetic field strength, the axial motor is lighter than the radial motor, and the axial motor structure is also easy to dissipate heat. Therefore, in order to solve the problems existing in linear motors, the magnetic flux path can be improved to reduce losses, reduce the weight of the motor to improve efficiency, achieve higher torque density, and increase heat dissipation capacity. The present invention proposes to replace the traditional alternating permanent magnets with two parallel permanent magnets with opposite magnetization directions, which can improve the magnetic flux path and improve the motor efficiency when the magnetic circuit is closed. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned technical problems and to propose an axial hybrid excitation double-pole linear motor to improve the torque density and efficiency of the motor. This type of motor has a simple, stable structure and high precision and is suitable for working in civilian equipment such as the packaging industry, CNC machine tools, and cordless elevators.

[0007] The present invention provides an axial hybrid excitation double salient pole linear motor, comprising: a primary (1), a three-phase armature winding (2), an excitation winding (3), a secondary (4), a primary tooth (5), a secondary tooth (6), and a permanent magnet (7). The primary (1) and the secondary (4) are salient pole tooth slot structures, the primary (1) is a stator fixed on a plane, the secondary (4) is a mover, there is an air gap between the primary (1) and the secondary (4), and the tooth gap of each primary tooth (5) is wound with a three-phase armature winding (2) and an excitation winding (3). The two ends of the primary iron core are disconnected, and the two ends of the secondary iron core are disconnected. Two sections of permanent magnets with the same length as the motor secondary pole are placed in parallel, with opposite magnetization directions, and together with the primary and secondary poles form a magnetic flux path. The specific magnetic flux path is a permanent magnet N, a secondary pole, a secondary pole tooth, an air gap between the primary and secondary poles, a primary tooth portion, a primary pole, a primary tooth portion, an air gap between the primary and secondary poles, a secondary pole tooth, a secondary pole, and a permanent magnet S.

[0008] Preferably, the axial hybrid excitation double-pole linear motor has a magnetic field provided by an excitation winding and a permanent magnet. An excitation current is passed through the excitation winding. The size and direction of the excitation current can be controlled to control the size of the excitation magnetic field and the magnetic flux path. The magnetic field direction of the permanent magnet is fixed after the motor is designed and is not easy to modify. It is a fixed permanent magnet magnetic field. The magnetic fields of the two together constitute the magnetic field of the motor.

[0009] Preferably, the primary of the axial hybrid excitation double-pole linear motor contains multiple coils, the coils are spaced apart along the primary direction of the motor, the primary teeth are stamped from silicon steel sheets, and the primary coils are divided into three-phase windings A, B, and C. When powered, the three-phase windings of the motor are powered, thereby driving the motor to move.

[0010] Preferably, the two permanent magnets of the axial hybrid excitation double-salient pole linear motor are placed in parallel with opposite magnetization directions. The distance between the two permanent magnets is small enough to reduce losses. The length of the two permanent magnets is equal to the length of the secondary pole of the motor. When the axial hybrid excitation double-salient pole motor moves, the permanent magnet can be arranged inside the secondary pole of the motor and can form a motor flux path together with the primary and secondary poles of the motor at any moment. Since the secondary pole length is shorter than the primary length in this example, the length of the permanent magnet can be reduced, the use of raw materials can be reduced, and costs can be saved.

[0011] Preferably, the magnetic flux path of the axial hybrid excitation double-salient pole linear motor is axial, which is defined according to the direction of the magnetic field in the air gap for realizing energy conversion, and the magnetization direction of the permanent magnet is changed from the radial magnetic flux of the traditional linear motor to the axial magnetic flux.

[0012] Preferably, when the axial hybrid excitation double-pole linear motor is used as a generator, after the winding on its primary side is energized, a corresponding magnetic field will be generated. The magnetic field can be constant or variable, and is realized by a DC power supply or an AC power supply, respectively, wherein the excitation winding and the armature winding are both centralized windings.

[0013] Preferably, the axial hybrid excitation double-salient pole linear motor has a compact structure, good rigidity, can withstand a large load, and has a high acceleration. It is suitable for occasions requiring rapid starting and rapid braking, and has a wide range of usable speeds.

[0014] Compared with the existing linear motor, the present invention has the following beneficial effects:

[0015] 1. In the axial hybrid excitation double-salient-pole linear motor structure proposed by the present invention, the primary tooth slots are wound with excitation windings, the excitation flux is evenly distributed, and when the secondary pole moves, the primary teeth and the secondary pole teeth will have overlapping parts at any time. When the armature current with the same phase as the magnetic potential is passed, the output torque can be increased, the power density can be increased, and the torque pulsation can be reduced, which has stability;

[0016] 2. The two permanent magnets of the present invention are placed in parallel, and the magnetization direction is axial. The magnetization directions of the two permanent magnets are opposite, and the axial magnetic flux can reduce the magnetic flux path;

[0017] 3. The present invention inherits the advantages of the simple structure of the double-salient-pole motor. The axial magnetic flux path can reduce the weight of the motor and the use of raw materials, which is conducive to reducing costs.

[0018] 4. The present invention only requires magnetizing two permanent magnets, which reduces the processing difficulty;

[0019] 5. The magnetic flux path of the present invention is shortened, the loss is reduced, and the magnetic field strength is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0021] Figure 2 are the magnetic lines of force when no excitation current is applied;

[0022] Figure 3 are the magnetic lines of force after the excitation current is passed;

[0023] Figure 4 The self-inductance waveform diagram of the A-phase winding of the embodiment;

[0024] Figure 5 The self-inductance waveform diagram of the B-phase winding of the embodiment;

[0025] Figure 6 The self-inductance waveform diagram of the C-phase winding of the embodiment;

[0026] Figure 7 is a self-inductance waveform diagram of the excitation winding of the embodiment;

[0027] Figure 8 is the axial flux path of an embodiment.

[0028] In the figure: 1. primary, 2. armature winding, 3. field winding, 4. secondary, 5. primary tooth, 6. secondary tooth, 7. permanent magnet. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] The present invention provides an axial hybrid excitation double salient pole linear motor structure, comprising: a primary (1), a three-phase armature winding (2), an excitation winding (3), a secondary (4), a primary tooth (5), a secondary tooth (6), and a permanent magnet (7). The primary (1) and the secondary (4) are salient pole tooth slot structures, the primary (1) is a stator fixed on a plane, the secondary (4) is a mover, there is an air gap between the primary (1) and the secondary (4), and the tooth gap of each primary tooth (5) is wound with a three-phase armature winding (2) and an excitation winding (3). The two ends of the primary iron core are disconnected, the two ends of the secondary iron core are disconnected, and two sections of permanent magnets of the same length are placed in parallel, with opposite magnetization directions, forming a magnetic flux path together with the primary and secondary.

[0031] When the permanent magnet is placed on the secondary pole surface, the permanent magnet on the secondary pole side can move with the secondary pole core to generate a magnetic field, which can directly interact with the magnetic field on the primary side to increase the output torque of the motor. Since the permanent magnet is located close to the air gap, the path length of the magnetic field is reduced, and a strong air gap magnetic field can be generated, thereby improving the output torque, power density and utilization rate of the magnetic field of the motor. The permanent magnet on the secondary pole surface can change the size and shape of the permanent magnet or perform other optimization designs according to different design requirements, change the distribution of the air gap magnetic field, and optimize the performance of the motor. Since the permanent magnet is on the pole surface of the secondary pole and is relatively fixed with the winding position on the primary side, the air gap magnetic field can be adjusted by adjusting the winding current on the primary side. For example, when the output torque needs to be increased, the size of the winding current can be increased so that the magnetic field generated by it is superimposed with the permanent magnetic field to enhance the air gap magnetic field; when the output torque needs to be reduced or braking is achieved, the current can be reversed so that the magnetic field generated by it is offset by the permanent magnetic field to weaken the air gap magnetic field. The installation method of the permanent magnet on the secondary pole surface is relatively simple and does not require additional space, which also makes the structure of the motor more compact. This structure can also be used in aerospace, electric vehicles and other fields. The permanent magnet generates a constant magnetic field on the secondary pole surface. When current is passed through the primary winding, a magnetic field is generated. The direction and magnitude of this magnetic field depend on the direction and magnitude of the current. The primary winding magnetic field interacts with the permanent magnetic field in the secondary pole to generate torque and drive the secondary pole to move. The axial hybrid excitation double-pole linear motor realizes the conversion of electrical energy and mechanical energy during operation.

[0032] When the permanent magnet is placed inside the secondary pole, it can protect the permanent magnet from the external environment and improve the reliability of the permanent magnet. The internal space of the secondary pole teeth is relatively large, and a permanent magnet of a certain size can be placed, thereby improving the magnetic energy of the permanent magnet. The choice of placing the permanent magnet inside the secondary pole of the motor effectively protects the permanent magnet, greatly reduces the impact of mechanical shock, high temperature, corrosion, etc., improves the reliability and service life of the permanent magnet, and also reduces motor failures caused by permanent magnet damage.

[0033] There is usually a certain amount of space inside the secondary pole of the axial hybrid excitation doubly salient linear motor, which can be fully utilized to place permanent magnets without significantly increasing the external size of the motor. This type of design can achieve miniaturization and lightweight of the motor without sacrificing motor performance. The magnetic field generated by the permanent magnet inside the secondary pole can be more evenly distributed in the air gap through the magnetic conductivity of the secondary pole tooth core, which helps to reduce magnetic field distortion and torque pulsation and improve the operating stability and efficiency of the motor. The permanent magnet inside the secondary pole can form a complex magnetic circuit together with the primary winding and the secondary pole core. By optimizing the magnetic circuit design, higher motor performance can be achieved. The magnetic field distribution and magnetic flux can be optimized by adjusting the shape, size and position of the permanent magnet and the structure of the secondary pole core. The permanent magnet generates a constant magnetic field inside the secondary pole, which passes through the air gap to the primary through the magnetic conductivity of the secondary pole core. When the secondary pole moves, the magnetic field generated by the permanent magnet also changes to form a magnetic field. When current is passed through the winding on the primary, a magnetic field is generated, and the direction and magnitude of the magnetic field depend on the direction and magnitude of the current.

[0034] The axial hybrid excitation double salient pole linear motor is also wound with an excitation winding, and the strength of the air gap magnetic field can be adjusted by adjusting the current in the excitation winding. When the output torque needs to be increased, the current in the excitation winding is increased so that the magnetic field generated by it is superimposed on the permanent magnetic field, thereby enhancing the air gap magnetic field; when the output torque needs to be reduced or braking is achieved, the current in the excitation winding can be reversed so that the magnetic field generated by it is offset by the original permanent magnetic field, thereby weakening the air gap magnetic field. The axial hybrid excitation double salient pole linear motor realizes the conversion of electrical energy and mechanical energy during operation.

[0035] In the present invention, each primary tooth slot has an excitation winding, and the magnetic flux path of each phase is the same, which reduces torque pulsation and improves torque density. Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 are the magnetic lines of force when no excitation current is applied; Figure 3 are the magnetic lines of force after the excitation current is passed; Figure 4 , 5 6 are the self-inductance waveform diagrams of the A, B, and C phase windings of the embodiment respectively.

[0036] Compared with the traditional linear motor, the magnetizing direction of the permanent magnet (7) of the axial linear motor of the present invention is changed from "left and right" of the traditional linear motor to "up and down", two permanent magnets with the same length as the secondary pole are placed side by side, the magnetizing direction of one permanent magnet is from the primary to the secondary, and the magnetizing direction of the other permanent magnet is from the secondary to the primary, the two directions are opposite, the permanent magnets are made of the same material, the two permanent magnets of the axial linear motor, the primary and the secondary together form a magnetic flux circuit, and the primary is fixed when the secondary moves with the rolling module.

[0037] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Axial hybrid excitation double-salient pole linear motor, characterized in that: include: The invention comprises a primary (1), a three-phase armature winding (2), an excitation winding (3), a secondary (4), a primary tooth (5), a secondary tooth (6), and a permanent magnet (7). The primary (1) and the secondary (4) are salient pole tooth slot structures. The primary (1) is a stator fixed on a plane, and the secondary (4) is a mover. There is an air gap between the primary (1) and the secondary (4). The tooth gap of each primary tooth (5) is wound with a three-phase armature winding (2) and an excitation winding (3).

2. The axial hybrid excitation double-salient pole linear motor according to claim 1, characterized in that: The width of the secondary teeth (6) is not less than the width of the primary teeth (5).

3. The axial hybrid excitation doubly salient linear motor according to claim 1, characterized in that: The motor flux is axial flux.

4. The axial hybrid excitation doubly salient linear motor according to claim 1, characterized in that: The three-phase armature winding (2) and the excitation winding (3) adopt a concentrated winding method.

5. The axial hybrid excitation doubly salient linear motor according to claim 1, characterized in that: The primary (1) and secondary (4) are made of laminated silicon steel sheets.

6. The axial hybrid excitation doubly salient linear motor according to claim 1, characterized in that: When the permanent magnet (7) is placed inside the secondary pole of the motor, the length of the permanent magnet is equal to the length of the secondary pole. The permanent magnet (7) has two sections, which are placed in parallel. The magnetization directions of the two sections are opposite, and together with the primary (1), the secondary (4), the primary teeth (5), the secondary teeth (6), and the air gap between the primary and secondary, an axial magnetic flux path is formed.

7. The axial hybrid excitation doubly salient linear motor according to claim 1, characterized in that: When the permanent magnet (7) is placed on the surface of the secondary pole of the motor, the permanent magnet, the primary pole (1), the secondary pole (4), the primary teeth (5), the secondary teeth (6) and the air gap between the primary and secondary poles of the motor together form an axial magnetic flux path.

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