Motor secondary assembly and linear motor

Abstract

The application provides a motor secondary assembly and a linear motor. The motor secondary assembly comprises a permanent magnet fixing plate and a permanent magnet assembly. The permanent magnet fixing plate has a permanent magnet mounting surface. The permanent magnet assembly comprises a first magnetic segment and a second magnetic segment. The first magnetic segment has a first matching surface. The second magnetic segment is arranged at the end of at least one end of the first magnetic segment in a first direction. The second magnetic segment is arranged close to the first end of the permanent magnet fixing plate in the first direction. The second magnetic segment has a second matching surface. In a second direction, the distance between at least a part of the first matching surface and the permanent magnet mounting surface is L1, and the distance between the second matching surface and the permanent magnet mounting surface is L2. L1 is greater than L2. According to the motor secondary assembly, the size of the end of the motor secondary assembly is reduced, the distortion of the air gap magnetic field is weakened, the end effect stress caused by uneven magnetic field distribution is effectively reduced, and the thrust fluctuation of the motor during operation is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of linear motor, more particularly, to a motor secondary assembly and a linear motor. BACKGROUND

[0002] The linear motor mainly includes permanent magnet synchronous linear motor and induction asynchronous linear motor, the structure of the permanent magnet synchronous linear motor is mostly short primary assembly and long secondary assembly, the primary assembly is mostly the tooth and slot structure of the iron core, the secondary assembly is mostly strong magnetic magnet material, the electromagnetic force is generated through the interaction of the magnetic field between the primary assembly and the secondary assembly, and the mover is pushed to move linearly. The existing permanent magnet synchronous motor mostly adopts the magnetic steel in Halbach arrangement mode, including the magnetic steel with axial magnetization and the magnetic steel with radial magnetization, the demagnetization of the magnetic steel with axial magnetization is obvious under the influence of high temperature, the thrust fluctuation is too large, and the working performance of the motor is affected. SUMMARY

[0003] An object of the present application is to provide a new technical solution of a motor secondary assembly, which can at least solve the problem of large motor thrust fluctuation in the prior art.

[0004] Another object of the present application is to provide a linear motor, which comprises the above motor secondary assembly.

[0005] In a first aspect, the present application provides a motor secondary assembly, which comprises a permanent magnet fixing plate having a permanent magnet mounting surface, a permanent magnet assembly arranged on the permanent magnet mounting surface, the permanent magnet assembly comprising: a first magnetic segment arranged along a first direction, the first magnetic segment having a first matching surface arranged on a side away from the permanent magnet mounting surface; and a second magnetic segment arranged along the first direction and arranged at an end of at least one end of the first magnetic segment in the first direction, the second magnetic segment being arranged close to a first end of the permanent magnet fixing plate in the first direction, the second magnetic segment having a second matching surface arranged on a side away from the permanent magnet mounting surface; in the second direction, the distance between the first matching surface and the permanent magnet mounting surface is L1, and the distance between the second matching surface and the permanent magnet mounting surface is L2, L1 being greater than L2; wherein the second direction is perpendicular to the first direction and perpendicular to the permanent magnet mounting surface.

[0006] Optionally, the permanent magnet assembly further comprises a third magnetic segment arranged along the first direction, and the third magnetic segment and the second magnetic segment are respectively located at two ends of the first magnetic segment in the first direction, the third magnetic segment is arranged close to the second end of the permanent magnet fixing plate in the first direction, the third magnetic segment has a third matching surface, the third matching surface is arranged on the side away from the permanent magnet mounting surface, and a distance between the third matching surface and the permanent magnet mounting surface in the second direction is S1, and L1 is greater than S1.

[0007] Optionally, the second magnetic segment and the third magnetic segment have the same structure.

[0008] Optionally, a size of the second magnetic segment in the first direction is H1, a total size of the first magnetic segment and the second magnetic segment in the first direction is L, and the H1 ranges from 1 / 16L to 1 / 3L.

[0009] Optionally, the first magnetic segment comprises a plurality of first permanent magnets and a plurality of second permanent magnets, the plurality of first permanent magnets and the plurality of second permanent magnets are alternately arranged on the permanent magnet mounting surface along the first direction, a magnetization direction of each first permanent magnet is parallel to the second direction, and a magnetization direction of each second permanent magnet is parallel to the first direction; wherein the first permanent magnet has the first matching surface, the second permanent magnet has a fourth matching surface, the fourth matching surface is arranged on the side away from the permanent magnet mounting surface, and a distance between the fourth matching surface and the permanent magnet mounting surface in the second direction is L3, and L1 is greater than L3.

[0010] Optionally, L2 = L3.

[0011] Optionally, a relationship between L3 and L1 satisfies 1 / 2L1 ≤ L3 ≤ 7 / 8L1.

[0012] Optionally, a size of the first permanent magnet in the first direction is smaller than a size of the second permanent magnet in the first direction.

[0013] Optionally, a permanent magnet grade of the second permanent magnet is greater than a permanent magnet grade of the first permanent magnet.

[0014] Optionally, a maximum magnetic energy product of the second permanent magnet is greater than a maximum magnetic energy product of the first permanent magnet.

[0015] Optionally, the first permanent magnet and the second permanent magnet form a pole pair, and four adjacent pole pairs form a unit permanent magnet, and in the first direction, the size of the unit permanent magnet is H, and the sum of the sizes of the first magnetic section and the second magnetic section in the first direction is L, and the H is in the range of L / H=n, wherein n is a positive integer.

[0016] Optionally, the n≥6.

[0017] Optionally, the second magnetic section includes a plurality of third permanent magnets and a plurality of fourth permanent magnets, and the plurality of third permanent magnets and the plurality of fourth permanent magnets are alternately arranged on the permanent magnet mounting surface along the first direction, and the third permanent magnets and the fourth permanent magnets have the second mating surface respectively, and in the second direction, the size of the third permanent magnet and the size of the fourth permanent magnet are the same.

[0018] Optionally, the first magnetic section and the second magnetic section respectively include a plurality of magnetic steels arranged along the first direction, and the magnetic steels of the first magnetic section and the second magnetic section are arranged in a Halbach manner.

[0019] Optionally, the permanent magnet fixing plate is a ring plate.

[0020] Optionally, the permanent magnet fixing plate is a circular ring plate, the permanent magnet mounting surface is an inner wall surface of the circular ring plate, the first direction is parallel to the axial direction of the circular ring plate, and the second direction is the radial direction of the circular ring plate.

[0021] Optionally, the first magnetic section and the second magnetic section are formed into a circular ring structure, the first connecting surface is a circular ring surface coaxial with the first magnetic section, and the second connecting surface is a circular ring surface coaxial with the second magnetic section.

[0022] In a second aspect, the application provides a linear motor, which includes the motor secondary assembly in any of the above embodiments.

[0023] Optionally, the linear motor further includes a motor primary assembly, the motor primary assembly includes an iron core and a winding, and the winding is arranged on the iron core; the permanent magnet fixing plate is a circular ring plate, the permanent magnet mounting surface is an inner wall surface of the circular ring plate, and the motor secondary assembly is sleeved on the motor primary assembly.

[0024] Optionally, in the second direction, the distance between the second mating surface and the outer wall surface of the iron core is H2, and the H2 is in the range of 1 / 7L2≤H2≤L2.

[0025] According to the motor secondary assembly of the application, by dividing the permanent magnet assembly into a first magnetic segment and a second magnetic segment, the second magnetic segment is arranged at the end of the first magnetic segment, and the distance between the second magnetic segment and the permanent magnet mounting surface is smaller than the distance between the first magnetic segment and the permanent magnet mounting surface, the size of the second magnetic segment in the second direction is reduced, and the distortion of the air gap magnetic field is reduced, the end effect stress caused by uneven magnetic field distribution can be effectively reduced, the thrust fluctuation of the motor during operation is reduced, and the operation stability and operation effect of the motor are effectively improved.

[0026] Other features of the application, and their advantages, will become apparent from the following detailed description of exemplary embodiments of the application, with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0028] Figure 1 is a sectional view of a motor secondary assembly and a motor primary assembly according to an embodiment of the application;

[0029] Figure 2 is Figure 1 is an enlarged view of the circled portion in A of FIG. 1;

[0030] Figure 3 is a sectional view of a first magnetic segment and a second magnetic segment in a motor secondary assembly according to an embodiment of the application;

[0031] Figure 4 is a schematic view of a first permanent magnet in a motor secondary assembly according to another embodiment of the application.

[0032] REFERENCE NUMERALS:

[0033] motor secondary assembly 100;

[0034] first magnetic segment 10; first permanent magnet 11; second permanent magnet 12; fourth mating surface 121; first connecting surface 13; first mating surface 14;

[0035] second magnetic segment 20; third permanent magnet 21; fourth permanent magnet 22; second connecting surface 23; second mating surface 24;

[0036] permanent magnet fixing plate 30; permanent magnet mounting surface 31;

[0037] third magnetic segment 40; third connecting surface 41; third mating surface 42;

[0038] motor primary assembly 200; iron core 201; winding 202. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0040] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0041] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0042] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0044] The motor secondary assembly 100 according to an embodiment of this application will now be described in detail with reference to the accompanying drawings.

[0045] like Figures 1 to 4 As shown, the motor secondary assembly 100 according to an embodiment of this application includes a permanent magnet fixing plate 30 and a permanent magnet assembly.

[0046] Specifically, the permanent magnet fixing plate 30 has a permanent magnet mounting surface 31, and a permanent magnet assembly is disposed on the permanent magnet mounting surface 31. The permanent magnet assembly includes a first magnetic segment 10 and a second magnetic segment 20. The first magnetic segment 10 is arranged along a first direction and has a first mating surface 14, which is located on the side away from the permanent magnet mounting surface 31. The second magnetic segment 20 is arranged along the first direction and is located at at least one end of the first magnetic segment 10 in the first direction. The second magnetic segment 20 is disposed near the first end of the permanent magnet fixing plate 30 in the first direction and has a second mating surface 24, which is located on the side away from the permanent magnet mounting surface 31. In the second direction, at least a portion of the first mating surface 14 is at a distance L1 from the permanent magnet mounting surface 31, and the second mating surface 24 is at a distance L2 from the permanent magnet mounting surface 31, where L1 is greater than L2; wherein, the second direction is perpendicular to the first direction and also perpendicular to the permanent magnet mounting surface 31. When the motor secondary assembly is used for a linear motor, the first direction is the direction of movement of the linear motor.

[0047] In other words, the motor secondary assembly 100 according to the embodiment of the present application is mainly composed of the permanent magnet fixing plate 30 and the permanent magnet assembly. The permanent magnet fixing plate 30 has a permanent magnet mounting surface 31 close to the end surface of the first magnetic section 10 and the second magnetic section 20, and the permanent magnet mounting surface 31 extends along the first direction. Specifically, the permanent magnet mounting surface 31 is an inner wall surface of the permanent magnet fixing plate 30, and the permanent magnet mounting surface 31 can be used to mount the permanent magnet assembly. The permanent magnet assembly cooperates with the permanent magnet fixing plate 30 to form the motor secondary assembly 100, thereby playing a magnetizing role, and the permanent magnet assembly can be composed of the first magnetic section 10 and the second magnetic section 20.

[0048] The first magnetic section 10 is arranged on the permanent magnet mounting surface 31 along the first direction, and the first magnetic section 10 has a first matching surface 14. The second magnetic section 20 is arranged on the permanent magnet mounting surface 31 along the first direction, and the second magnetic section 20 is arranged at the end of at least one end of the first magnetic section 10 in the first direction, and the second magnetic section 20 is close to the first end of the permanent magnet fixing plate 30 in the first direction. Alternatively, in the first direction, the second magnetic section 20 can be mounted at the end of any one end of the first magnetic section 10, and the second magnetic section 20 can also be mounted at the ends of both ends of the first magnetic section 10, that is, in the motor secondary assembly 100 composed of the first magnetic section 10 and the second magnetic section 20, the second magnetic section 20 serves as the end of at least one end of the motor secondary assembly 100.

[0049] Alternatively, the first magnetic section 10 further comprises a first connecting surface 13, the first matching surface 14 and the first connecting surface 13 are oppositely arranged in the second direction, the first connecting surface 13 is connected with the permanent magnet mounting surface 31, and the first magnetic section 10 can be mounted on the permanent magnet mounting surface 31 through the first connecting surface 13.

[0050] In addition, the second magnetic section 20 also has a second matching surface 24, and the distance between the first matching surface 14 and the permanent magnet mounting surface 31 in the second direction is L1, that is, the size of at least a part of the first magnetic section 10 in the second direction is L1; the distance between the second matching surface 24 and the permanent magnet mounting surface 31 is L2, that is, the size of the second magnetic section 20 in the second direction is L2, and L1 is greater than L2, so that the size of the second magnetic section 20 in the second direction is smaller than the size of at least a part of the first magnetic section 10. The first direction is perpendicular to the second direction, and the second direction is perpendicular to the permanent magnet mounting surface 31, thereby determining the extension direction of the first direction and the second direction.

[0051] Alternatively, the second magnetic section 20 further comprises a second matching surface 24, and the second connecting surface 23 and the second matching surface 24 can be symmetrically arranged in the second direction, the second connecting surface 23 is connected with the permanent magnet mounting surface 31, and the second magnetic section 20 can be mounted on the permanent magnet mounting surface 31 through the second connecting surface 23.

[0052] Therefore, according to the motor secondary assembly 100 of the present application, by dividing the permanent magnet assembly into the first magnetic segment 10 and the second magnetic segment 20, and mounting the second magnetic segment 20 at the end of the first magnetic segment 10 in the first direction; at the same time, in the second direction, the size of the second magnetic segment 20 is smaller than the size of the first magnetic segment 10, that is, in the motor secondary assembly 100 composed of the first magnetic segment 10 and the second magnetic segment 20, the thickness of the end of the motor secondary assembly 100 in the second direction is cut, that is, the size of the end of the motor secondary assembly 100 in the second direction is reduced, which can reduce the traveling wave magnetic field of the second magnetic segment 20 and other parts of the motor, weaken the air gap magnetic field distortion, reduce the magnetic leakage phenomenon, effectively reduce the thrust fluctuation in the operation of the motor, and further effectively reduce the end effect and thrust fluctuation of the motor, and improve the operation effect and stability of the linear motor.

[0053] According to an embodiment of the present application, the permanent magnet assembly further comprises a third magnetic segment 40, the third magnetic segment 40 is arranged along the first direction, and the third magnetic segment 40 and the second magnetic segment 20 are respectively located at both ends of the first magnetic segment 10 in the first direction, the third magnetic segment 40 is arranged close to the second end of the permanent magnet fixing plate 30 in the first direction, the third magnetic segment 40 has a third matching surface 42, the third magnetic segment 40 is arranged on the side away from the permanent magnet mounting surface 31, and in the second direction, the distance between the third matching surface 42 and the permanent magnet mounting surface 31 is S1, and L1 is greater than S1.

[0054] In other words, the permanent magnet assembly further comprises a third magnetic segment 40 arranged along the first direction, and the second magnetic segment 20 and the third magnetic segment 40 are respectively mounted at both ends of the first magnetic segment 10, and at the same time, L2 and S1 are both smaller than L1, that is, in the second direction, the size of the first magnetic segment 10 is greater than the size of the second magnetic segment 20 and the size of the third magnetic segment 40, and therefore, in the permanent magnet assembly composed of the first magnetic segment 10, the second magnetic segment 20 and the third magnetic segment 40, the sizes of both ends of the permanent magnet assembly are smaller than the size of the middle part of the permanent magnet, and the magnetic field fluctuation at both ends of the permanent magnet assembly is weakened.

[0055] And the third magnetic segment 40 further comprises a third connecting surface 41, the third connecting surface 41 is connected with the permanent magnet mounting surface 31, and the third magnetic segment 40 can be mounted on the permanent magnet mounting surface 31 through the third connecting surface 41.

[0056] Therefore, in the second direction, the size of the second magnetic segment 20 and the size of the third magnetic segment 40 are both smaller than the size of the first magnetic segment 10, that is, the size of the two ends of the motor secondary assembly 100 is smaller than the size of the middle part of the motor secondary assembly 100, that is, the size of the end part of the two ends of the motor secondary assembly 100 is reduced, which can effectively reduce the traveling wave magnetic field of the two ends of the motor secondary assembly 100, further weaken the air gap magnetic field distortion, and reduce the magnetic leakage phenomenon, thereby effectively reducing the thrust fluctuation and the end effect, and improving the operation stability of the motor.

[0057] According to some embodiments of the present application, the second magnetic segment 20 and the third magnetic segment 40 have the same structure.

[0058] Specifically, the second magnetic segment 20 and the third magnetic segment 40 have the same structure and the same size in the first direction as in the second direction, that is, S1=L2, so that the size of the two ends of the motor secondary assembly 100 is more regular and has stronger stability.

[0059] In other words, in the second direction, the size of the two ends of the motor secondary assembly 100 is the same and smaller than the size of the middle part of the motor secondary assembly 100, so that the end part of the two ends of the motor secondary assembly 100 obtains a uniform size, so that the traveling wave magnetic field of the two ends of the motor secondary assembly 100 obtains an equal reduction effect, further weakens the air gap magnetic field distortion in the linear motor, and reduces the magnetic leakage phenomenon, thereby effectively reducing the thrust fluctuation and the end effect, and improving the operation stability of the motor.

[0060] According to other embodiments of the present application, the size of the second magnetic segment 20 in the first direction is H1, and the sum of the sizes of the first magnetic segment 10 and the second magnetic segment 20 in the first direction is L, and H1 is in the range of: 1 / 16L≤H1≤1 / 3L.

[0061] Specifically, in the first direction, the size of the second magnetic segment 20 is H1, and the total size of the first magnetic segment 10 and the second magnetic segment 20 is L. Optionally, L can be the total size of one first magnetic segment 10 and one second magnetic segment 20; L can also be the total size of one first magnetic segment 10 and multiple second magnetic segments 20. The relationship between H1 and L satisfies 1 / 16L≤H1≤1 / 3L, that is, the relationship between H1 and L can be H1=1 / 16L; the relationship between H1 and L can also be H1=1 / 10L; the relationship between H1 and L can also be H1=1 / 3L, which can be adjusted according to the actual demand of the linear motor.

[0062] Thus, the length of the second magnetic section 20 is optimized. A suitable length can effectively reduce the traveling wave magnetic field at the end of the motor secondary assembly 100, thereby reducing the occurrence of air gap magnetic field distortion and magnetic leakage. In this way, the motor secondary assembly 100 has a large thrust while having a small thrust fluctuation. If the length of the second magnetic section 20 is too long, the thrust of the motor secondary assembly 100 will be small, which will cause the working effect of the motor to be poor. If the length of the second magnetic section 20 is too short, the weakening effect of the traveling wave magnetic field at the end of the motor secondary assembly 100 will be poor, that is, the motor secondary assembly 100 still has a large end effect, which is prone to thrust fluctuation, thereby reducing the stability of the linear motor.

[0063] In some embodiments of the present application, the first magnetic section 10 includes a plurality of first permanent magnets 11 and a plurality of second permanent magnets 12, and the plurality of first permanent magnets 11 and the plurality of second permanent magnets 12 are alternately arranged along the first direction on the permanent magnet mounting surface 31. The magnetization direction of each first permanent magnet 11 is parallel to the second direction, and the magnetization direction of each second permanent magnet 12 is parallel to the first direction. The first permanent magnet 11 and the second permanent magnet 12 each have a first connecting surface 13. The first permanent magnet 11 has a first mating surface 14, and the second permanent magnet 12 has a fourth mating surface 121 opposite the first connecting surface 13 along the second direction. In the second direction, the distance between the fourth mating surface 121 and the permanent magnet mounting surface 31 is L3, and L1 is greater than L3.

[0064] In other words, the first magnetic section 10 is mainly composed of a plurality of first permanent magnets 11 and a plurality of second permanent magnets 12, and the plurality of first permanent magnets 11 and the plurality of second permanent magnets 12 can be alternately arranged along the first direction on the permanent magnet mounting surface 31. There are many ways to arrange the first permanent magnet and the second permanent magnet, for example, the first permanent magnet 11 and the second permanent magnet 12 can be alternately arranged along the first direction; the plurality of first permanent magnets 11 and the plurality of second permanent magnets 12 can be alternately arranged along the first direction; two first permanent magnets 11 form a group, two second permanent magnets 12 form a group, and a group of first permanent magnets 11 and a group of second permanent magnets 12 are alternately arranged, etc.

[0065] The first permanent magnet 11 and the second permanent magnet 12 have a first connecting surface 13 respectively, and the end surface of the first permanent magnet 11 and the second permanent magnet 12 close to one end of the permanent magnet mounting surface 31 is the first connecting surface 13. The end surface of the first permanent magnet 11 away from the permanent magnet mounting surface 31 and corresponding to the first connecting surface 13 is a first matching surface 14, and the end surface of the second permanent magnet 12 away from the permanent magnet mounting surface 31 and corresponding to the first connecting surface 13 is a fourth matching surface 121. The fourth matching surface 121 is away from the permanent magnet mounting surface 31 by a distance L3 in the second direction, and L1 is greater than L3. That is, in the second direction, the size of the first permanent magnet 11 is greater than the size of the second permanent magnet 12. In the first magnetic section 10, the first permanent magnet 11 and the second permanent magnet 12 can form a fluctuating alternating structure, and the thrust fluctuation in the linear motor can be reduced to improve the stability of the linear motor operation.

[0066] Since the magnetization direction of the first permanent magnet 11 is parallel to the second direction, the first permanent magnet 11 mainly provides a main magnetic field in the motor secondary assembly 100, and the magnetization direction of the second permanent magnet 12 is parallel to the first direction, and the second permanent magnet 12 mainly provides a magnetic flux path in the motor secondary assembly 100. Therefore, the size of the second permanent magnet 12 in the second direction is smaller than the size of the first permanent magnet 11 in the second direction. Compared with the size of the second permanent magnet 12 in the second direction being equal to the size of the first permanent magnet 11 in the second direction, the size of the second permanent magnet 12 in the second direction is reduced, which is not easy to affect the magnetic field in the motor secondary assembly 100, and the maximum thrust output of the linear motor is guaranteed, the thrust fluctuation in the linear motor is effectively reduced, and the operation stability of the motor is improved. Moreover, reducing the size of the second permanent magnet 12 in the second direction can effectively reduce the risk of demagnetization of the second permanent magnet 12 at high temperature, so that the linear motor can maintain large thrust and high efficiency operation at a higher operating temperature.

[0067] Therefore, the first permanent magnet 11 and the second permanent magnet 12 in the first magnetic section 10 can form a fluctuating alternating structure. Compared with the size of the first permanent magnet 11 and the second permanent magnet 12 in the first magnetic section 10 being consistent, the thrust fluctuation can be effectively reduced, and the thrust output of the linear motor can be maintained, that is, the operation stability and operation effect of the motor can be guaranteed.

[0068] According to some optional embodiments of the present application, L2=L3.

[0069] Specifically, the size of the second permanent magnet 12 in the second direction is the same as the size of the second magnetic section 20 in the second direction. That is, the second permanent magnet 12 can obtain the same or similar reduction effect on the air gap magnetic field in the motor secondary assembly 100 as the second magnetic section 20, thereby weakening the air gap magnetic field distortion, reducing the magnetic leakage phenomenon, further reducing the thrust fluctuation during the operation of the linear motor, effectively reducing the end effect and thrust fluctuation of the motor secondary assembly 100, and improving the operation effect and stability of the linear motor.

[0070] According to some optional embodiments of the present application, the relationship between L3 and L1 satisfies 1 / 2L1≤L3≤7 / 8L1.

[0071] Specifically, the size of the second permanent magnet 12 in the second direction satisfies 1 / 2L1≤L3≤7 / 8L1. In the second direction, optionally, the size of the first permanent magnet 11 and the size of the second permanent magnet 12 can satisfy L3=1 / 2L1; the size of the first permanent magnet 11 and the size of the second permanent magnet 12 can also satisfy L3=5 / 8L1; and the size of the first permanent magnet 11 and the size of the second permanent magnet 12 can also satisfy L3=7 / 8L1.

[0072] Therefore, the size of the second permanent magnet 12 in the second direction is optimized, and the appropriate size can reduce the traveling wave magnetic field and thrust fluctuation formed by the second permanent magnet 12, and also can maintain an appropriate thrust size, so that the motor can maintain a better operation effect. If the size of the second permanent magnet 12 is too small, it will have a greater impact on the magnetic field and thrust size of the linear motor, and the operation effect of the motor will be poor. If the size of the second permanent magnet 12 is too large, it will not have a greater improvement on the thrust fluctuation in the linear motor, that is, the motor will still be affected by the thrust fluctuation during operation.

[0073] According to one embodiment of the present application, the size of the first permanent magnet 11 in the first direction is smaller than the size of the second permanent magnet 12 in the first direction.

[0074] Specifically, in the first direction, the size of the first permanent magnet 11 is larger than the size of the second permanent magnet 12, which further optimizes the size of the second permanent magnet 12 in the second direction, not only reduces the size of the second permanent magnet 12 in the second direction, but also increases the size of the second permanent magnet 12 in the first direction. In other words, while sufficiently reducing the traveling wave magnetic field and thrust fluctuation formed by the second permanent magnet 12, the thrust output of the second permanent magnet 12 is ensured, and the operation stability of the linear motor is improved.

[0075] According to some embodiments of the present application, the permanent magnet grade of the second permanent magnet 12 is greater than the permanent magnet grade of the first permanent magnet 11.

[0076] Specifically, the second permanent magnet 12 can be N48 or N45, and the first permanent magnet 11 can be N42 or N40, which can be selected according to actual needs. Since the size of the second permanent magnet 12 is smaller than that of the first permanent magnet 11 in the second direction and in the first direction, the second permanent magnet 12 is made of a material with a larger permanent magnet grade, which enhances the remanence and coercive force of the second permanent magnet 12, greatly reduces the demagnetization phenomenon of the second permanent magnet 12 at high temperature, and maintains the thrust size of the motor secondary assembly 100 while reducing the amount of magnetic steel used by the second permanent magnet 12. In other words, the permanent magnet grade of the second permanent magnet 12 is greater than that of the first permanent magnet 11, which can make the magnetic force of the first permanent magnet 11 similar to that of the second permanent magnet 12, and maintain the thrust output of the linear motor.

[0077] In some embodiments of the present application, the maximum magnetic energy product of the second permanent magnet 12 is greater than that of the first permanent magnet 11.

[0078] In detail, when the permanent magnet grade of the second permanent magnet 12 is N48, the maximum magnetic energy product of the second permanent magnet 12 ranges from 46-48 MGOe, and when the permanent magnet grade of the first permanent magnet 11 is N42, the maximum magnetic energy product of the first permanent magnet 11 ranges from 40-42 MGOe; or when the permanent magnet grade of the second permanent magnet 12 is N45, the maximum magnetic energy product of the second permanent magnet 12 ranges from 42-45 MGOe, and when the permanent magnet grade of the first permanent magnet 11 is N40, the maximum magnetic energy product of the first permanent magnet 11 ranges from 38-40 MGOe. The second permanent magnet 12 is made of a magnetic steel material with a larger magnetic energy product. Since the size of the second permanent magnet 12 is smaller than that of the first permanent magnet 11 in the second direction and in the first direction, by increasing the magnetic energy product of the second permanent magnet 12, the thrust loss of the second permanent magnet 12 due to the reduction in size is compensated for, thereby improving the thrust output of the second permanent magnet 12 and maintaining the use effect of the linear motor with large thrust and high efficiency.

[0079] According to some optional embodiments of the present application, the adjacent first permanent magnet 11 and the second permanent magnet 12 cooperate to form a pole pair, and four adjacent pole pairs form a unit permanent magnet. In the first direction, the size of the unit permanent magnet is H, and the sum of the sizes of the first magnetic segment 10 and the second magnetic segment 20 in the first direction is L. The range of H is L / H=n, where n is a positive integer.

[0080] Specifically, the magnetization directions of the adjacent first permanent magnet 11 and the second permanent magnet 12 are perpendicular to each other, and then the adjacent first permanent magnet 11 and the second permanent magnet 12 can form a pole pair with different magnetization directions. Four adjacent pole pairs can form a unit permanent magnet. The magnetization directions of the plurality of first permanent magnets 11 and the plurality of second permanent magnets 12 in the unit permanent magnet are in turn parallel to the second direction and away from the permanent magnet mounting surface 31, parallel to the first direction and toward the left side of the Figure 2 , parallel to the second direction and toward the permanent magnet mounting surface 31, and parallel to the first direction and toward the right side of the Figure 2 . The above reciprocation forms a cycle. The thrust of the unit permanent magnet is relatively appropriate. By forming the motor secondary assembly 100 by a plurality of unit permanent magnets, it is convenient to form a suitable motor secondary assembly 100 according to the use requirement, and then the linear motor can obtain the operation effect of large thrust and high efficiency.

[0081] According to an embodiment of the present application, n≥6.

[0082] Specifically, the number of unit permanent magnets in the motor secondary assembly 100 is greater than or equal to six. Optionally, the number of unit permanent magnets in the motor secondary assembly 100 can be six, eight, or ten, which can be adjusted according to the actual demand of the motor. In other words, the motor secondary assembly 100 has more than six unit permanent magnets, which can obtain a relatively excellent and stable thrust size, that is, the linear motor has the operation effect of large thrust and high efficiency.

[0083] According to some embodiments of the present application, the second magnetic section 20 includes a plurality of third permanent magnets 21 and a plurality of fourth permanent magnets 22. The plurality of third permanent magnets 21 and the plurality of fourth permanent magnets 22 are alternately arranged along the first direction on the permanent magnet mounting surface 31. The third permanent magnet 21 and the fourth permanent magnet 22 respectively have a second connecting surface 23 and a second matching surface 24. In the second direction, the size of the third permanent magnet 21 and the size of the fourth permanent magnet 22 are the same.

[0084] In other words, the second magnetic section 20 is composed of a plurality of third permanent magnets 21 and a plurality of fourth permanent magnets 22. The plurality of third permanent magnets 21 and the plurality of fourth permanent magnets 22 are alternately arranged. Optionally, the third permanent magnet 21 and the fourth permanent magnet 22 can be alternately arranged along the first direction; the plurality of third permanent magnets 21 and the plurality of fourth permanent magnets 22 can also be alternately arranged along the first direction; or two third permanent magnets 21 form a group, two fourth permanent magnets 22 form a group, and a group of third permanent magnets 21 and a group of fourth permanent magnets 22 are alternately arranged.

[0085] Each third permanent magnet 21 and each fourth permanent magnet 22 has a second connection surface 23 at an end of the permanent magnet close to the end of the permanent magnet mounting surface 31, and each third permanent magnet 21 and each fourth permanent magnet 22 has a second matching surface 24 at an end of the permanent magnet away from the permanent magnet mounting surface 31 and corresponding to the second connection surface 23. In the second direction, the distance between the second matching surface 24 and the second connection surface 23 is L2, that is, the size of the third permanent magnet 21 in the second direction is the same as the size of the fourth permanent magnet 22 in the second direction.

[0086] In addition, since the sizes of the third permanent magnet and the fourth permanent magnet in the second direction are the same, that is, the size of the second magnetic section in the second direction is the same, and since the second magnetic section is mounted at the end of the first magnetic section, the shape of the end of the permanent magnet assembly is regular, which is conducive to reducing the thrust fluctuation in the permanent magnet assembly.

[0087] Therefore, by making the sizes of the third permanent magnet and the fourth permanent magnet in the second direction the same, the size of the end of the motor secondary assembly 100 is small and the shape is regular, which can reduce the traveling wave magnetic field generated by the third permanent magnet 21 and the fourth permanent magnet 22, weaken the air gap magnetic field distortion, and further reduce the magnetic leakage phenomenon, so that the thrust fluctuation change is much smaller than the thrust fluctuation in the linear motor in which the motor secondary assembly 100 is located when the motor is running, and the end effect stress and the thrust fluctuation of the linear motor are effectively reduced.

[0088] According to some embodiments of the present application, the first magnetic section 10 and the second magnetic section 20 each include a plurality of magnetic steels arranged in the first direction, and the magnetic steels of the first magnetic section 10 and the second magnetic section 20 are arranged in a Halbach manner.

[0089] In other words, since the magnetic steels in the first magnetic section 10 are arranged in a Halbach manner, that is, in the first magnetic section 10, the magnetization direction of the first permanent magnet 11 is parallel to the second direction, and the magnetization direction of the second permanent magnet 12 is parallel to the first direction, and the magnetization directions of the two adjacent first permanent magnets 11 are opposite, and the magnetization directions of the two adjacent second permanent magnets 12 are opposite, so that the first magnetic section 10 can form a Halbach structure. Since the magnetic steels in the second magnetic section 20 are arranged in a Halbach manner, that is, in the second magnetic section 20, the magnetization direction of the third permanent magnet 21 is parallel to the second direction, and the magnetization direction of the fourth permanent magnet 22 is parallel to the first direction, and the magnetization directions of the two adjacent third permanent magnets 21 are opposite, and the magnetization directions of the two adjacent fourth permanent magnets 22 are opposite, so that the second magnetic section 20 can form a Halbach structure. That is, the magnetic steels in the first permanent magnet 11 and the second permanent magnet 12 are arranged in a Halbach manner, which can enhance the single-side strengthening effect of the motor secondary assembly 100, that is, effectively enhance the thrust of the linear motor.

[0090] In some embodiments of the present application, the size of the third permanent magnet 21 in the first direction is smaller than the size of the fourth permanent magnet 22 in the first direction.

[0091] Specifically, since the size of the fourth permanent magnet 22 in the first direction is larger than the size of the third permanent magnet 21 in the first direction, the size of the fourth permanent magnet 22 in the second direction is further optimized, thereby not only reducing the size of the fourth permanent magnet 22 in the second direction, but also increasing the size of the fourth permanent magnet 22 in the first direction, thereby sufficiently reducing the fluctuation of the traveling wave magnetic field and the thrust generated by the third permanent magnet 21, maintaining the thrust output of the fourth permanent magnet 22, improving the operation stability of the motor while reducing the amount of magnetic steel.

[0092] According to some optional embodiments of the present application, the size of the first permanent magnet 11 in the first direction is equal to the size of the third permanent magnet 21 in the first direction, and the size of the second permanent magnet 12 in the first direction is equal to the size of the fourth permanent magnet 22 in the first direction.

[0093] Specifically, in the first direction, the size of the first permanent magnet 11 is equal to the size of the third permanent magnet 21, and the size of the second permanent magnet 12 is equal to the size of the fourth permanent magnet 22, so that the shape of the fourth permanent magnet 22 is consistent with the shape of the second permanent magnet 12, thereby the third permanent magnet 21 can stably provide the main magnetic field, and the fourth permanent magnet 22 can stably provide the magnetic flux path, while weakening the end effect of the motor secondary assembly 100, the thrust of the motor secondary assembly 100 is maintained.

[0094] According to some optional embodiments of the present application, the grade of the permanent magnet of the third permanent magnet 21 is greater than the grade of the first permanent magnet 11, and the grade of the fourth permanent magnet 22 is greater than the grade of the second permanent magnet 12.

[0095] Specifically, the grade of the permanent magnet of the third permanent magnet 21 can be N45 or N48, and the grade of the permanent magnet of the fourth permanent magnet 22 can be N50 or N52, which can be selected according to actual needs. Since the size of the third permanent magnet 21 in the second direction is smaller than the size of the first permanent magnet 11 in the second direction, the second permanent magnet 12 is made of a material with a larger grade, which enhances the remanence and coercive force of the third permanent magnet 21, can greatly reduce the occurrence of demagnetization of the second permanent magnet 12 at high temperature, while reducing the amount of magnetic steel of the third permanent magnet 21, the thrust of the motor secondary assembly 100 is maintained. In other words, the grade of the permanent magnet of the third permanent magnet 21 is greater than the grade of the first permanent magnet 11, which can make the magnetic force of the first permanent magnet 11 similar to the magnetic force of the third permanent magnet 21, and maintain the thrust output of the linear motor.

[0096] The fourth permanent magnet 22 is made of a material with a larger permanent magnet grade than the second permanent magnet 12, which can further increase the remanence and coercive force of the fourth permanent magnet 22, maintain the thrust of the second magnetic section 20, i.e., increase the thrust of the end of the motor secondary assembly 100, and maintain the use effect of the linear motor.

[0097] According to one embodiment of the present application, the maximum magnetic energy product of the third permanent magnet 21 is greater than the maximum magnetic energy product of the first permanent magnet 11, and the maximum magnetic energy product of the fourth permanent magnet 22 is greater than the maximum magnetic energy product of the second permanent magnet 12.

[0098] Specifically, when the permanent magnet grade of the fourth permanent magnet 22 is N50, the maximum magnetic energy product of the fourth permanent magnet 22 ranges from 47-51 MGOe, when the permanent magnet grade of the second permanent magnet 12 is 48, the maximum magnetic energy product of the second permanent magnet 12 ranges from 46-48 MGOe, or when the permanent magnet grade of the fourth permanent magnet 22 is N52, the maximum magnetic energy product of the fourth permanent magnet 22 ranges from 50-53 MGOe, and when the permanent magnet grade of the second permanent magnet 12 is 45, the maximum magnetic energy product of the second permanent magnet 12 ranges from 38-40 MGOe. When the permanent magnet grade of the third permanent magnet 21 is N45, the maximum magnetic energy product of the third permanent magnet 21 ranges from 47-51 MGOe, when the permanent magnet grade of the first permanent magnet 11 is N42, the maximum magnetic energy product of the first permanent magnet 11 ranges from 40-42 MGOe, or when the permanent magnet grade of the third permanent magnet 21 is N52, the maximum magnetic energy product of the third permanent magnet 21 ranges from 50-53 MGOe, and when the permanent magnet grade of the first permanent magnet 11 is N40, the maximum magnetic energy product of the first permanent magnet 11 ranges from 38-40 MGOe. The third permanent magnet 21 is made of a magnetic steel material with a larger magnetic energy product. Since the size of the third permanent magnet 21 in the second direction is smaller than the size of the first permanent magnet 11, by increasing the magnetic energy product of the third permanent magnet 21, the thrust loss of the third permanent magnet 21 due to the size reduction is compensated, thereby increasing the thrust output of the third permanent magnet 21 and maintaining the use effect of the motor secondary assembly 100 with large thrust and high efficiency. Since the fourth permanent magnet 22 is located at the end, by increasing the maximum magnetic energy product of the fourth permanent magnet 22, the remanence and coercive force of the fourth permanent magnet 22 can be further increased, thereby effectively reducing the end effect of the linear motor and enabling the linear motor to run smoothly.

[0099] According to some other embodiments of the present application, the permanent magnet fixing plate 30 is an annular plate.

[0100] Specifically, since the permanent magnet fixing plate 30 is a ring-shaped plate, the permanent magnet fixing plate 30 can be sleeved outside the motor secondary assembly 100 and synchronously moved with the motor secondary assembly 100, and the first permanent magnet 11, the second permanent magnet 12, the third permanent magnet 21 and the fourth permanent magnet 22 connected to the permanent magnet fixing plate 30 can be distributed along the permanent magnet fixing plate 30 and form a ring shape, thereby stably providing a magnetic field.

[0101] In some embodiments of the present application, the permanent magnet fixing plate 30 is a circular ring-shaped plate, the permanent magnet mounting surface 31 is an inner wall surface of the circular ring-shaped plate, the first direction is parallel to the axial direction of the circular ring-shaped plate, and the second direction is the radial direction of the circular ring-shaped plate.

[0102] Alternatively, the permanent magnet fixing plate 30 is a circular ring-shaped plate, and the permanent magnet mounting surface 31 is an inner wall surface of the permanent magnet fixing plate 30. Since the first connecting surface 13 of the first permanent magnet 11 and the second permanent magnet 12 and the second connecting surface 23 of the third permanent magnet 21 and the fourth permanent magnet 22 are connected to the permanent magnet mounting surface 31, the first permanent magnet 11, the second permanent magnet 12, the third permanent magnet 21 and the fourth permanent magnet 22 can be distributed along the permanent magnet fixing plate 30 and form a circular ring shape, thereby further stably providing a magnetic field in the linear motor. The second direction is the radial direction of the permanent magnet fixing plate 30, and the first direction is parallel to the axial direction of the permanent magnet fixing plate 30, that is, the magnetization direction of the first permanent magnet 11 and the third permanent magnet 21 is the radial direction, and the magnetization direction of the second permanent magnet 12 and the fourth permanent magnet 22 is the axial direction.

[0103] Therefore, the magnetization directions of the plurality of first permanent magnets 11 and the plurality of second permanent magnets 12 in one unit permanent magnet are in turn radial magnetization toward the center of the circular ring-shaped plate, axial magnetization toward one second magnetic segment 20, radial magnetization away from the center of the circular ring-shaped plate, and axial magnetization toward another second magnetic segment 20, which is repeated and forms a cycle. That is, the first permanent magnet 11 is a radial magnetization permanent magnet, and the second permanent magnet 12 is an axial magnetization permanent magnet.

[0104] According to some optional embodiments of the present application, the first magnetic segment 10 and the second magnetic segment 20 are respectively formed in a circular ring structure

[0105] Specifically, the first permanent magnet 11, the second permanent magnet 12, the third permanent magnet 21 and the fourth permanent magnet 22 are all circular ring structures, so that the outer wall surfaces of the first permanent magnet 11, the second permanent magnet 12, the third permanent magnet 21 and the fourth permanent magnet 22 can be attached to and connected to the permanent magnet mounting surface 31, thereby effectively improving the connection firmness between the first magnetic segment 10 and the second magnetic segment 20.

[0106] Optionally, the first permanent magnet 11 and the second permanent magnet 12 can each be a fan ring block structure, the circular ring is cut along two non-overlapping straight lines from the center, and the cut part is the fan ring block. A plurality of first permanent magnets 11 are arranged along the permanent magnet mounting surface 31. Optionally, a plurality of first permanent magnets 11 are sequentially connected at the head and tail and arranged along the permanent magnet mounting surface 31, that is, a plurality of first permanent magnets 11 can form a circular ring structure; a plurality of first permanent magnets 11 can be spaced apart and arranged along the permanent magnet mounting surface 31. A plurality of second permanent magnets 12 are arranged along the permanent magnet mounting surface 31. Optionally, a plurality of second permanent magnets 12 are sequentially connected at the head and tail and arranged along the permanent magnet mounting surface 31, that is, a plurality of second permanent magnets 12 can form a circular ring structure; a plurality of second permanent magnets 12 can be spaced apart and arranged along the permanent magnet mounting surface 31.

[0107] Therefore, the motor secondary assembly 100 is composed of a plurality of fan ring blocks, the magnetic field formed by the plurality of first permanent magnets 11 and the magnetic field formed between the plurality of second permanent magnets 12 are effectively improved, that is, the thrust in the motor secondary assembly 100 is strengthened, and the operation and use effect of the motor is improved.

[0108] The application also provides a linear motor comprising the motor secondary assembly 100 according to any one of the above embodiments. Since the motor secondary assembly 100 according to the application has the above technical effects, the linear motor according to the application also has corresponding technical effects, that is, since the second magnetic segment 20 is arranged at the end of the first magnetic segment 10 and the size of the second magnetic segment 20 in the second direction is reduced, the distortion of the air gap magnetic field is reduced, the end effect stress caused by uneven magnetic field distribution can be effectively reduced, the thrust fluctuation of the motor during operation is reduced, and the operation stability and effect of the motor are effectively improved.

[0109] According to some optional embodiments of the application, the linear motor further comprises a motor primary assembly 200, wherein the motor primary assembly 200 comprises a core 201 and a winding 202, the winding 202 is arranged on the core 201; the permanent magnet fixing plate 30 is a circular ring plate, the permanent magnet mounting surface 31 is the inner wall surface of the circular ring plate, and the motor secondary assembly 100 is sleeved on the motor primary assembly 200.

[0110] Specifically, the linear motor is composed of the motor secondary assembly 100 and the motor primary assembly 200, the motor secondary assembly 100 is sleeved on the motor primary assembly 200, and the permanent magnet fixing plate 30 is sleeved outside the motor secondary assembly 100, and the motor secondary assembly 100 can move along the axial direction of the core 201. In the first direction, the size of the motor primary assembly 200 is larger than the size of the motor secondary assembly 100, that is, a structure that the motor secondary assembly 100 is short and the motor primary assembly 200 is long is formed in the linear motor. The motor primary assembly 200 is composed of the core 201 and the winding 202, and the winding 202 is wound outside the core 201.

[0111] Therefore, the air gap magnetic field distribution of the linear motor presents a non-closed, linear distribution, the two ends of the stator side of the linear motor are disconnected, causing the three-phase winding 202 to be asymmetrically distributed, the magnetic flux distribution in the gap formed between the motor secondary assembly 100 and the motor primary assembly 200 is uneven, the air gap magnetic field is distorted, the end effect force directly acts on the motor, the motor generates vibration and noise, the motor control difficulty is increased, and the end effect and thrust fluctuation are generated. Therefore, the motor secondary assembly 100 includes a first magnetic segment 10 and a second magnetic segment 20. In the second direction, the size of the second magnetic segment 20 is smaller than the size of the first magnetic segment 10, that is, the size of the second magnetic segment 20 is reduced, thereby reducing the thickness of the two ends of the motor secondary assembly 100, and thereby reducing the traveling wave magnetic field between the second magnetic segment 20 and the iron core 201, weakening the air gap magnetic field distortion, thereby reducing the magnetic flux leakage phenomenon. When the magnetic field of the motor primary assembly 200 interacts with the magnetic field of the second magnetic segment 20, compared with the structure in which the size of the second magnetic segment 20 is not reduced, the thrust fluctuation is greatly reduced, effectively improving the stability of the motor operation and maintaining the size of the motor thrust.

[0112] Optionally, the linear motor further includes a sliding bearing piece, a first end of the sliding bearing piece is connected with the second matching surface 24 of the second magnetic segment 20, that is, the sliding bearing piece is embedded in the second magnetic segment 20, and a second end of the sliding bearing piece is connected with the iron core 201. Therefore, the mechanical friction between the sliding bearing piece and the motor primary can be effectively reduced, and the output efficiency and thrust can be improved.

[0113] According to some optional embodiments of the present application, in the second direction, the distance between the second matching surface 24 and the outer wall surface of the iron core 201 is H2, and H2 is in the range of: 1 / 7L2≤H2≤L2.

[0114] Specifically, in the second direction, a first gap can be formed between the second matching surface 24 and the outer wall surface of the iron core 201, the distance between the second matching surface 24 and the outer wall surface of the iron core 201 is H2, and the relationship between H2 and the size L2 of the second magnetic segment 20 satisfies 1 / 7L2≤H2≤L2. Optionally, the relationship between H2 and L2 can be H2=1 / 7L2; the relationship between H2 and L2 can be H2=3 / 7L2; the relationship between H2 and L2 can be H2=L2, which can be adjusted according to actual needs.

[0115] In some specific embodiments of the present application, the iron core 201 is formed as a tooth and slot structure. The iron core 201 adopting the tooth and slot structure as the motor primary assembly 200 effectively improves the thrust density in the linear motor, so that the motor secondary assembly 100 has fewer numbers of magnets, which can maintain the operation effect of the linear motor; and can also improve the heat dissipation effect of the linear motor.

[0116] According to some optional embodiments of the present application, the distribution of the winding 202 adopts a fractional slot structure, which is not shown in the figure. Compared with the integer slot structure, the thrust fluctuation of the fractional slot structure is greatly reduced, which can further reduce the noise generated by the motor and improve the operation stability of the motor.

[0117] Thus, the relationship between the size of the second magnetic segment 20 and the size of the first gap in the second direction is optimized, and appropriately reducing the size of the second magnetic segment 20 can weaken the traveling wave magnetic field between the second magnetic segment 20 and the core 201, the air gap magnetic field distortion, and the magnetic leakage phenomenon, thereby reducing the thrust fluctuation of the motor and improving the operation stability of the motor. If the size of the second magnetic segment 20 in the second direction is too large, the influence on the thrust fluctuation of the motor is small, and the motor still has the problem of poor stability. If the size of the second magnetic segment 20 in the second direction is too small, the influence on the thrust of the motor is large, that is, the thrust at the second magnetic segment 20 is small, which affects the thrust of the motor.

[0118] According to some optional embodiments of the present application, in the second direction, because the size of the first permanent magnet 11 is larger than the size of the second permanent magnet 12, the first matching surface 14 and the outer wall surface of the core 201 can form a second gap, and the fourth matching surface 121 and the outer wall surface of the core 201 can form a third gap, the size of the third gap is larger than the size of the second gap, and because the first permanent magnet 11 and the second permanent magnet 12 are alternately distributed, the second gap and the third gap are alternately arranged.

[0119] Because the air gap magnetic field distribution of the linear motor presents a non-closed and linear distribution, the open ends of the stator side of the linear motor cause the asymmetric distribution of the three-phase winding 202, which causes the magnetic flux distribution in the gap formed between the motor secondary assembly 100 and the motor primary assembly 200 to be uneven, the air gap magnetic field is distorted, and the core tooth structure also generates a tooth gap positioning force, that is, there are many other forces affecting the thrust in the linear motor.

[0120] Thus, through the alternating and fluctuating gap distribution between the first magnetic segment 10 and the outer wall surface of the core 201, the tooth gap positioning force and the thrust fluctuation of the linear motor are effectively reduced, the operation stability of the linear motor is improved, and the linear motor obtains large thrust and high efficiency.

[0121] Although some specific embodiments of the present application have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration, but not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An electric machine secondary assembly characterized by, The application relates to a permanent magnet fixing plate and a permanent magnet assembly. The permanent magnet fixing plate has a permanent magnet mounting surface. The permanent magnet assembly is arranged on the permanent magnet mounting surface and comprises: a first magnetic segment arranged along a first direction, the first magnetic segment having a first matching surface arranged on a side away from the permanent magnet mounting surface; a second magnetic segment arranged along the first direction and arranged at an end of the first magnetic segment in the first direction, the second magnetic segment being arranged close to a first end of the permanent magnet fixing plate in the first direction, the second magnetic segment having a second matching surface arranged on a side away from the permanent magnet mounting surface; in a second direction, the distance between the first matching surface and the permanent magnet mounting surface is L1, and the distance between the second matching surface and the permanent magnet mounting surface is L2, wherein L1 is greater than L2; wherein the second direction is perpendicular to the first direction and perpendicular to the permanent magnet mounting surface; the first magnetic segment comprises a plurality of first permanent magnets and a plurality of second permanent magnets, the plurality of first permanent magnets and the plurality of second permanent magnets being alternately arranged on the permanent magnet mounting surface along the first direction, the magnetization direction of each first permanent magnet being parallel to the second direction, and the magnetization direction of each second permanent magnet being parallel to the first direction; wherein the first permanent magnet has the first matching surface, the second permanent magnet has a fourth matching surface arranged on a side away from the permanent magnet mounting surface, and in the second direction, the distance between the fourth matching surface and the permanent magnet mounting surface is L3, wherein L1 is greater than L3.

2. The motor secondary assembly of claim 1, wherein, The permanent magnet assembly further comprises: a third magnetic segment arranged along the first direction, the third magnetic segment and the second magnetic segment being respectively arranged at two ends of the first magnetic segment in the first direction, the third magnetic segment being arranged close to a second end of the permanent magnet fixing plate in the first direction, the third magnetic segment having a third matching surface arranged on a side away from the permanent magnet mounting surface, and in the second direction, the distance between the third matching surface and the permanent magnet mounting surface is S1, wherein L1 is greater than S1.

3. The motor secondary assembly of claim 2, wherein, The second magnetic segment and the third magnetic segment have the same structure.

4. The motor secondary assembly of claim 1, wherein, The size of the second magnetic segment in the first direction is H1, the total size of the first magnetic segment and the second magnetic segment in the first direction is L, and the range of H1 is 1 / 16L <= H1 <= 1 / 3L.

5. The motor subassembly of claim 1, wherein, L2 = L3.

6. The motor subassembly of claim 1, wherein, The relationship between L3 and L1 satisfies 1 / 2L1 <= L3 <= 7 / 8L1.

7. The motor secondary assembly of claim 1, wherein, The size of the first permanent magnet in the first direction is smaller than the size of the second permanent magnet in the first direction.

8. The motor subassembly of claim 1, wherein, The permanent magnet grade of the second permanent magnet is greater than the permanent magnet grade of the first permanent magnet.

9. The motor secondary assembly of claim 1, wherein, The maximum magnetic energy product of the second permanent magnet is greater than the maximum magnetic energy product of the first permanent magnet.

10. The motor subassembly of claim 1, wherein, The first permanent magnet and the second permanent magnet form a pole pair, and four adjacent pole pairs form a unit permanent magnet.

11. The motor secondary assembly of claim 10, wherein, The n is greater than or equal to 6.

12. The motor secondary assembly of claim 1, wherein, The second magnetic section includes a plurality of third permanent magnets and a plurality of fourth permanent magnets, and the third permanent magnets and the fourth permanent magnets are alternately arranged on the permanent magnet mounting surface along the first direction.

13. The motor secondary assembly of claim 1, wherein, The first magnetic section and the second magnetic section each include a plurality of magnetic steels arranged along the first direction, and the magnetic steels of the first magnetic section and the second magnetic section are arranged in a Halbach array.

14. The motor secondary assembly of claim 1, wherein, The permanent magnet fixing plate is a ring-shaped plate.

15. The motor secondary assembly of claim 14, wherein, The permanent magnet fixing plate is a circular ring-shaped plate, the permanent magnet mounting surface is an inner wall surface of the circular ring-shaped plate, the first direction is parallel to an axial direction of the circular ring-shaped plate, and the second direction is a radial direction of the circular ring-shaped plate.

16. The motor secondary assembly of claim 14, wherein, The first magnetic section and the second magnetic section each have a circular ring-shaped structure.

17. A linear motor, characterized by The motor primary assembly includes an iron core and a winding, and the winding is arranged on the iron core.

18. The linear motor of claim 17, wherein, The motor primary assembly includes an iron core and a winding, and the winding is arranged on the iron core. The permanent magnet fixing plate is a circular ring-shaped plate, the permanent magnet mounting surface is an inner wall surface of the circular ring-shaped plate, the motor secondary assembly is sleeved on the motor primary assembly. In the second direction, a distance between the second matching surface and an outer wall surface of the iron core is H2, and the H2 is in a range of 1 / 7L2≤H2≤L2.

19. The linear motor of claim 18, wherein, ​

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