High power density permanent magnet linear motor

Abstract

The embodiment of the application discloses a high-power-density permanent magnet linear motor, which comprises a primary assembly and a secondary assembly, the primary assembly comprises a primary core, the primary core is composed of a primary yoke part and a primary tooth part, the primary tooth part is provided with an excitation winding, and auxiliary excitation magnet units are arranged at pole shoes of the primary tooth part, the auxiliary excitation magnet units comprise 2n permanent magnets with N poles and S poles staggered and uniformly arranged.

Description

Technical Field

[0001] This invention relates to the field of linear motor technology, and in particular to a high power density permanent magnet linear motor. Background Technology

[0002] In the field of permanent magnet synchronous motors, their advantages such as high efficiency, high power density, and strong overload capacity have led to their widespread application in industry, agriculture, aviation, and automotive sectors. However, with the new national standards imposing further requirements on motor energy consumption, traditional permanent magnet synchronous motors face a significant challenge: increasing power density necessitates a larger amount of permanent magnets, which substantially increases costs.

[0003] Having permanent magnets on the secondary side of a linear motor has many drawbacks, such as poor utilization of permanent magnets, increased costs, difficulty in transportation, assembly, and storage, and a high risk factor. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a high power density permanent magnet linear motor to improve power density.

[0005] To address the aforementioned technical problems, this invention proposes a high-power-density permanent magnet linear motor, comprising a primary assembly and a secondary assembly. The primary assembly includes a primary iron core, which is composed of a primary yoke and a primary tooth. Each pole shoe of the primary tooth is provided with an auxiliary excitation magnet unit, which includes 2n permanent magnets with N and S poles arranged alternately and uniformly.

[0006] Furthermore, the two adjacent permanent magnets of the auxiliary excitation magnet unit are set as a group of permanent magnets, and there are a total of n groups of permanent magnets. The distance between the two permanent magnets in each group is the same.

[0007] Furthermore, the secondary component consists of a secondary yoke and secondary teeth, and the distance between the two permanent magnets in each group of permanent magnets is equal to the width of the secondary teeth.

[0008] Furthermore, the adjacent groups of permanent magnets are arranged in close proximity.

[0009] Furthermore, the two permanent magnets at the beginning and end of the auxiliary excitation magnet unit have the same height, denoted as L3; satisfying: L1-L3<1mm; where L1 is the height of the pole shoe of the primary tooth.

[0010] Furthermore, the permanent magnets in the middle of the auxiliary excitation magnet unit have the same height, denoted as L2; ​​where 2L2 < L1.

[0011] Furthermore, the permanent magnets of the auxiliary excitation magnet unit are arranged in a flat pattern along the secondary motion direction or arranged in a Halebeck array.

[0012] Furthermore, the secondary components are straight-tooth structures, helical-tooth structures, or multi-displacement helical-tooth structures.

[0013] The beneficial effects of this invention are as follows: This invention increases the air gap magnetic flux density of the linear motor by placing permanent magnets on the primary side of the linear motor. At the same time, a special combination of the arrangement and magnetization direction of the permanent magnets can not only further increase the air gap magnetic flux density of the motor, but also correct the air gap magnetic field of the motor, reduce the amount of permanent magnets used, and reduce the cost of the motor. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a high power density permanent magnet linear motor according to Embodiment 1 of the present invention.

[0015] Figure 2 This is a schematic diagram of the structure of a single primary tooth in Embodiment 1 of the present invention.

[0016] Figure 3 This is a schematic diagram of the structure of the secondary component in Embodiment 1 of the present invention.

[0017] Figure 4 This is a schematic diagram of the structure of two adjacent sets of permanent magnets in Embodiment 1 of the present invention when there is no regional material between them.

[0018] Figure 5 This is a schematic diagram of the structure of the filling area material between two adjacent sets of permanent magnets in Embodiment 1 of the present invention.

[0019] Figure 6 This is a schematic diagram of the auxiliary excitation magnet unit in Embodiment 2 of the present invention.

[0020] Figure 7 This is a schematic diagram of the magnetic field direction of the high power density permanent magnet linear motor in Embodiment 1 of the present invention.

[0021] Explanation of icon numbers Primary component 10, excitation winding 11, primary yoke 12, primary tooth 13, permanent magnet 14, secondary component 20, secondary yoke 21, secondary tooth 22, regional material 35. Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0024] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0025] Please refer to Figures 1 to 7 The high power density permanent magnet linear motor of this invention includes a primary component and a secondary component. The primary component and the secondary component are separated by a motor air gap. The size of the air gap is determined by a combination of manufacturing process level, assembly level, and other performance requirements of the motor.

[0026] The primary assembly includes a primary core, which consists of several primary yokes and primary teeth. The length of the primary core can be freely chosen indefinitely, and is generally m times the number of slots or teeth in the motor. m is the number of phases in the motor.

[0027] Each pole piece of the primary gear is equipped with an auxiliary excitation magnet unit, which consists of 2n permanent magnets with N and S poles arranged alternately and evenly. The permanent magnets are divided into N-pole permanent magnets and S-pole permanent magnets. In Example 1, n=2; please refer to [reference needed]. Figure 1 , Figure 2 , Figure 4 , Figure 5 In Example 2, n=3; please refer to... Figure 6 .

[0028] The primary iron core is slotted to form stator slots, and the excitation windings are embedded in the stator slots in the form of coils. By changing the connection order of the beginning and end of several different excitation windings (coils), different winding connection structures can be arranged. Only one set of windings that generate a sinusoidal magnetic field and are linked can be selected.

[0029] In one implementation, adjacent permanent magnets of the auxiliary excitation magnet unit are set as a group of permanent magnets, with a total of n groups of permanent magnets. The distance between the two permanent magnets in each group is the same. Material is used to fill the spaces between adjacent groups of permanent magnets.

[0030] In one implementation, the secondary component consists of a secondary yoke and secondary teeth, wherein the distance between the two permanent magnets in each group of permanent magnets is equal to the width of the secondary teeth. The secondary length is determined based on the stroke and the primary length. In specific implementations, the secondary salient pole structure may or may not contain permanent magnets.

[0031] Two adjacent permanent magnets are magnetized in opposite directions, that is, the N pole and S pole permanent magnets are arranged alternately. 2n permanent magnets are evenly arranged on a primary tooth. Two adjacent permanent magnets are set as a group of permanent magnets, and there are a total of n groups of permanent magnets. Generally, the distance between two permanent magnets in each group corresponds to a secondary tooth. At this time, the output of the motor with the same volume can be maximized.

[0032] In one implementation, adjacent groups of permanent magnets are arranged in a close-fitting manner. In a specific implementation, the material between two adjacent groups of permanent magnets may be absent; that is, the next permanent magnet in the previous group is arranged adjacent to the previous permanent magnet in the next group (i.e., the width of the material between the groups is 0). Figure 5 Region 35 material can also exist. In this case, the material in region 35 can be air, epoxy resin, or other materials with weak magnetic permeability, or silicon steel sheets or other materials with strong magnetic permeability.

[0033] In one implementation, the two permanent magnets at the beginning and end of the auxiliary excitation magnet unit have the same height, denoted as L3; satisfying: L1-L3<1 mm; where L1 is the height of the pole shoe of the primary tooth.

[0034] In one implementation, the permanent magnets in the middle of the auxiliary excitation magnet unit have the same height, denoted as L2; ​​where 2L2 < L1.

[0035] In one implementation, the permanent magnets of the auxiliary excitation magnet unit are arranged in a flat arrangement along the secondary motion direction or in a Halebeck array arrangement.

[0036] The secondary component structure can be a straight tooth structure, a helical tooth structure, or a multi-misaligned helical tooth structure.

[0037] The principle of this invention is as follows: An alternating current that varies with time is passed through the coil (excitation winding). This current, combined with the iron core, generates an alternating rotating magnetic field. Based on the principle of minimum magnetic reluctance, the motor's working magnetic flux enters the air gap through the permanent magnets and acts on the secondary teeth, thus causing continuous movement of the secondary windings. Permanent magnets of different polarities respectively facilitate the entry of magnetic flux into the secondary teeth or impede its entry. The function of permanent magnets of different polarities varies at different times and positions, and is constantly changing.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high power density permanent magnet linear motor comprising a primary assembly and a secondary assembly, the primary assembly comprising a primary core and an excitation winding, the primary core consisting of a primary yoke portion and a primary tooth portion, characterized in that, Each pole shoe of the primary tooth section is equipped with an auxiliary excitation magnet unit, which consists of 2n permanent magnets with N and S poles arranged alternately and evenly. The auxiliary excitation magnet unit consists of two adjacent permanent magnets as a group of permanent magnets, and there are a total of n groups of permanent magnets. The distance between the two permanent magnets in each group is the same. The two permanent magnets at the beginning and end of the auxiliary excitation magnet unit have the same height, denoted as L3; satisfying: L1-L3<1mm; where L1 is the height of the pole shoe of the primary tooth; The permanent magnets in the middle of the auxiliary excitation magnet unit have the same height, denoted as L2; ​​where 2L2 < L1.

2. The high power density permanent magnet linear motor of claim 1, the secondary assembly is composed of a secondary yoke and secondary teeth, characterized in that, The distance between the two permanent magnets in each group is equal to the width of the secondary tooth.

3. The high power density permanent magnet linear motor of claim 1, wherein, The permanent magnets are arranged in close proximity to each other.

4. The high power density permanent magnet linear motor of claim 1, wherein, The permanent magnets of the auxiliary excitation magnet unit are arranged in a flat pattern along the secondary motion direction or in a Heilbeck array.

5. The high power density permanent magnet linear motor of any one of claims 1-4, wherein, The secondary components are either straight-tooth or helical-tooth structures.

Images