Novel Halbach magnet array linear motor

Abstract

The invention discloses a novel Halbach magnet array linear motor, and belongs to the technical field of linear motors, the novel Halbach magnet array linear motor comprises an upper back iron and a lower back iron which are oppositely arranged, the opposite surfaces of the upper back iron and the lower back iron are respectively provided with a magnet array, and a coil assembly is arranged between the two magnet arrays. Each polar distance of the magnet array comprises deflection magnet groups and horizontal magnets, the deflection magnet groups and the horizontal magnets are periodically and alternately distributed according to a Halbach magnet array mode, and the magnetization directions of every two adjacent horizontal magnets are alternately distributed along the positive direction and the negative direction of the X axis respectively; a deflection magnet group is arranged between every two adjacent horizontal magnets, each deflection magnet group comprises a plurality of sub-magnets which are connected in sequence, and an included angle is formed between the magnetization direction of the sub-magnets and the Z axis. According to the magnet array structure of the motor, the single-side magnetism gathering characteristic of the Halbach array is maintained, and meanwhile the energy utilization rate and stability of the linear motor are improved through multi-section coordinated regulation and control of the magnetic field vector.

Description

Technical Field

[0001] The present invention relates to the technical field of linear motors, and in particular to a novel Halbach magnet array linear motor. Background Art

[0002] Permanent magnet linear motors can be divided into two categories based on their magnetic circuit structure: iron-core and iron-coreless. As direct drive devices for linear motion, they combine the high power density characteristics of permanent magnet motors with the mechanical transmission-free advantages of linear drives. They have been widely used in industrial automation, high-speed logistics transmission, precision CNC machining, and semiconductor manufacturing.

[0003] The primary of an iron-core permanent magnet linear motor uses a silicon steel core, which has low magnetic circuit reluctance and high air gap flux density. This offers the advantages of high thrust density, but due to the inherent properties of ferromagnetic materials, it also has significant disadvantages, including thrust fluctuations caused by cogging and end effects, dynamic response hysteresis caused by core loss, and excessive mover mass. These shortcomings restrict the system's acceleration and submicron positioning accuracy, making it difficult to meet the stringent requirements of high-dynamic, high-precision scenarios such as lithography wafer stages and ultra-precision measuring instruments. The primary of an ironless permanent magnet linear motor consists only of coils, without ferromagnetic material. This successfully addresses the aforementioned shortcomings of the iron-core structure, achieving zero cogging / normal force, low inductance, and ultra-low inertia. Acceleration can reach 35g, and positioning accuracy has also entered the submicron level, reaching ±0.1 micron, significantly improving the system's dynamic performance and positioning accuracy.

[0004] Figure 1 This is a three-dimensional structure diagram of a traditional ironless linear motor, which mainly includes an upper back iron 1, a lower back iron 2, an upper magnet array 3 fixed to the inner surface of the upper back iron 1 and a lower magnet array 4 fixed to the inner surface of the lower back iron 2, a U-shaped connecting block 5 and a coil assembly 6. The magnetization direction of the upper magnet array 3 and the lower magnet array 4 is shown in FIG. Figure 2 This magnetization method is a traditional two-stage Halbach magnet array mode magnet array arrangement method, the first section of the magnet is magnetized in the Z direction up / down, and the second section of the magnet is magnetized in the horizontal x direction left / right.

[0005] However, under the traditional Halbach magnet array magnetization method, the spatial superposition effect of the magnetic fields generated by the first segment magnetized in the Z direction and the second segment magnetized in the X direction is not ideal. Because the magnetization directions of the two segments are relatively single and fixed, the magnetic fields they generate weaken each other in some areas and fail to fully enhance each other in other areas. This leads to an uneven distribution of the magnetic field in the air gap, and a large amount of magnetic field energy cannot be concentrated in the area that can effectively generate thrust, resulting in energy waste. At the same time, at the junction of the first and second segments, the magnetic field direction suddenly changes at a right angle, resulting in a discontinuous distribution of the air gap magnetic field. When the rotor coil passes through such a sudden change area, the electromagnetic thrust will produce periodic fluctuations due to the sudden change in magnetic field strength, directly affecting the smoothness of movement. Summary of the Invention

[0006] The purpose of the present invention is to provide a novel Halbach magnet array linear motor to solve the technical problems in the prior art that the Halbach magnet array has a single magnetizing angle, resulting in low energy utilization and poor stability.

[0007] As conceived above, the technical solution adopted by the present invention is:

[0008] A novel Halbach magnet array linear motor includes an upper back iron and a lower back iron disposed opposite each other, wherein a magnet array is disposed on each opposing surface of the upper back iron and the lower back iron, and a coil assembly is disposed between the two magnet arrays. Each pole pitch of the magnet array includes:

[0009] A deflection magnet group and a horizontal magnet are periodically and alternately distributed according to a Halbach magnet array pattern. The magnetization directions of each adjacent two horizontal magnets are alternately distributed along the positive direction and the reverse direction of the X-axis. A deflection magnet group is arranged between each adjacent two horizontal magnets. The deflection magnet group includes a plurality of sub-magnets connected in sequence, and the magnetization directions of the sub-magnets are arranged at an angle to the Z-axis.

[0010] Preferably, the deflection magnet group includes two sub-magnets connected in sequence, the angle between the magnetization directions of the two sub-magnets of the same deflection magnet group and the Z-axis is the deflection angle θ, and the magnetization directions of the two sub-magnets are symmetrically arranged about the Z-axis, and the magnetization directions of two adjacent deflection magnet groups are alternately distributed about the positive direction and the reverse direction of the Z-axis.

[0011] Preferably, in the magnet array located on the upper back iron, in the deflection magnet group whose magnetization direction is distributed in the positive direction of the Z-axis, the magnetization directions of the two sub-magnets are inclined outward in a direction away from each other and the angle between them and the positive direction of the Z-axis is the deflection angle θ; in the deflection magnet group whose magnetization direction is distributed in the opposite direction of the Z-axis, the magnetization directions of the two sub-magnets are inclined inward in a direction approaching each other and the angle between them and the negative direction of the Z-axis is the deflection angle θ.

[0012] Preferably, in the magnet array located in the lower back iron, in the deflection magnet group whose magnetization direction is distributed in the positive direction of the Z-axis, the magnetization directions of the two sub-magnets are inclined inwardly in a direction approaching each other and the angle between them and the positive direction of the Z-axis is the deflection angle θ; in the deflection magnet group whose magnetization direction is distributed in the negative direction of the Z-axis, the magnetization directions of the two sub-magnets are inclined outwardly in a direction away from each other and the angle between them and the negative direction of the Z-axis is the deflection angle θ.

[0013] Preferably, the deflection angle θ is greater than or equal to 12 degrees and less than or equal to 16 degrees.

[0014] Preferably, the cross-sectional shape of the sub-magnet is a rectangle or a right-angled trapezoid, and the cross-sectional shape of the deflection magnet group composed of a plurality of the sub-magnets is a rectangle.

[0015] Preferably, the cross-section of the horizontal magnet is rectangular, the horizontal magnet and the deflection magnet group have the same height, and the horizontal magnet and the deflection magnet group together constitute the rectangular magnet array.

[0016] Preferably, the sub-magnets are rectangular, and the cross-sectional sizes of any two sub-magnets are the same.

[0017] Preferably, the width of the sub-magnet is greater than the width of the horizontal magnet.

[0018] Preferably, the width of the sub-magnet is a first width value ω1, and the first width value ω1 is greater than or equal to 7.5 mm and less than or equal to 8.5 mm.

[0019] Beneficial effects of the present invention:

[0020] The present invention proposes a novel Halbach magnet array linear motor. Its magnet array consists of a periodically alternating array of deflection magnet groups and horizontal magnets within each pole pitch. The magnetization directions of the horizontal magnets alternate along the X-axis, while each deflection magnet group consists of multiple sub-magnets, each magnetized at an angle to the Z-axis, connected in sequence. This angular magnetization characteristic of the deflection magnet groups creates a multi-stage, gradually varying magnetic field distribution in the transition region between the horizontal magnets. The angles between the sub-magnets' magnetization directions and the Z-axis effectively adjust the direction of the magnetic field vector, transforming the magnetic field variation between the deflection magnet group and adjacent horizontal magnets from a single, abrupt change in direction to a multi-stage, continuous transition. As the coil assembly moves within the magnetic field, the multiple sub-magnets of the deflection magnet group, through their staged magnetization angles, gradually guide the magnetic field direction from the Z-axis toward the X-axis, thereby forming a smooth magnetic field gradient within the air gap. This magnetic field superposition not only enhances the uniformity of magnetic flux density within the effective working area but also reduces the local magnetic field line distortion caused by sudden changes in magnetic field direction in traditional structures. The alternating positive and negative magnetization directions of the horizontal magnets further cooperate with the gradient magnetic field of the deflection magnet group, so that the air gap magnetic field forms a highly consistent periodic distribution pattern in the direction of motion of the mover (i.e., the X-axis direction). The electromagnetic thrust generated thereby has a more stable intensity distribution in the spatial dimension, which weakens the periodic thrust fluctuations caused by the discontinuity of the magnetic field. In addition, the multi-sub-magnet segmented design of the deflection magnet group can more accurately control the magnetic field diffusion path, concentrate more magnetic field energy in the effective action area that interlinks with the coil assembly, reduce the leakage loss of the edge magnetic flux, and thus improve the magnetic field utilization. In summary, the magnet array structure of the motor maintains the unilateral magnetic concentration characteristics of the Halbach array while achieving the unity of high-stable thrust output and high energy density through multi-segment coordinated control of the magnetic field vector, thereby improving the energy utilization and stability of the linear motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of a traditional linear motor provided in the background technology;

[0022] Figure 2 Schematic diagram of the structure of a traditional two-stage Halbach magnet array provided in the background art;

[0023] Figure 3 1 is a schematic structural diagram of a novel Halbach magnet array linear motor provided by an embodiment of the present invention;

[0024] Figure 4 1 is a schematic structural diagram of a magnet array provided in an embodiment of the present invention;

[0025] Figure 51 is a graph showing how the average thrust and peak-to-peak thrust fluctuations of a novel Halbach magnet array coreless linear motor provided by an embodiment of the present invention vary with the deflection angle θ;

[0026] Figure 6 is a relationship diagram between the first width value ω1 of the sub-magnet provided by an embodiment of the present invention and the electromagnetic thrust characteristics;

[0027] Figure 7 is the first height value h of the sub-magnet provided in the embodiment of the present invention m The relationship diagram of electromagnetic thrust characteristics;

[0028] Figure 8 This is a comparison diagram of the magnetic flux density characteristics of the linear motor in the no-load air gap provided by the background technology of the embodiment of the present invention and the embodiment of the present invention;

[0029] Figure 9 This is a comparison diagram of the thrust waveforms of the linear motor in the no-load air gap provided by the background technology of the embodiment of the present invention and this embodiment.

[0030] In the picture:

[0031] 1. Upper back iron; 2. Lower back iron; 3. Upper magnet array; 4. Lower magnet array; 5. U-shaped connecting block; 6. Coil assembly; 7. Magnet array; 71. Deflection magnet group; 711. Sub-magnet; 72. Horizontal magnet. DETAILED DESCRIPTION

[0032] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but are not to be construed as limiting the present invention.

[0033] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0034] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] Figure 1 This is a three-dimensional structural diagram of a traditional ironless coreless linear motor, which mainly includes an upper back iron 1, a lower back iron 2, an upper row of magnet arrays 3 fixed to the inner surface of the upper back iron 1 and a lower row of magnet arrays 4 fixed to the inner surface of the lower back iron 2, a U-shaped connecting block 5 and a coil assembly 6.

[0037] Figure 2 It is the magnetization direction of the upper magnet array 3 and the lower magnet array 4. This magnetization method is the arrangement method of the traditional two-stage Halbach magnet array mode magnet array. The first section of the magnet is magnetized in the Z direction up / down, and the second section of the magnet is magnetized in the horizontal x direction left / right.

[0038] The Halbach magnet array pattern is an existing technology that optimizes magnetic field distribution by arranging permanent magnets in a specific direction. Its core feature is the periodic combination of magnetization directions, which concentrates magnetic field energy on one side (such as the working air gap) while significantly weakening the magnetic field on the other side (reducing magnetic flux leakage). This array pattern has been widely used in fields such as linear motors and magnetic levitation. Its specific principles and implementation are not detailed here.

[0039] However, under the traditional Halbach magnet array magnetization method, the spatial superposition effect of the magnetic fields generated by the first segment magnetized in the Z direction and the second segment magnetized in the X direction is not ideal. Because the magnetization directions of the two segments are relatively single and fixed, the magnetic fields they generate weaken each other in some areas and fail to fully enhance each other in other areas. This leads to an uneven distribution of the magnetic field in the air gap, and a large amount of magnetic field energy cannot be concentrated in the area that can effectively generate thrust, resulting in energy waste. At the same time, at the junction of the first and second segments, the magnetic field direction suddenly changes at a right angle, resulting in a discontinuous distribution of the air gap magnetic field. When the rotor coil passes through such a sudden change area, the electromagnetic thrust will produce periodic fluctuations due to the sudden change in magnetic field strength, directly affecting the smoothness of movement.

[0040] See also Figures 1 to 4 The new Halbach magnet array linear motor provided by an embodiment of the present invention includes an upper back iron 1 and a lower back iron 2 arranged opposite to each other, a magnet array 7 is respectively provided on the opposite surfaces of the upper back iron 1 and the lower back iron 2, a coil assembly 6 is provided between the two magnet arrays 7, and each pole pitch of the magnet array 7 includes a deflection magnet group 71 and a horizontal magnet 72. The deflection magnet group 71 and the horizontal magnet 72 are periodically alternately distributed according to the Halbach magnet array pattern, and the magnetization directions of each adjacent two horizontal magnets 72 are alternately distributed along the positive direction and the reverse direction of the X-axis respectively. A deflection magnet group 71 is provided between each adjacent two horizontal magnets 72, and the deflection magnet group 71 includes a plurality of sub-magnets 711 connected in sequence, and the magnetization directions of the sub-magnets 711 are arranged at an angle to the Z-axis.

[0041] The present invention proposes a novel Halbach magnet array linear motor. Its magnet array 7 comprises a periodically alternating arrangement of deflection magnet groups 71 and horizontal magnets 72 within each pole pitch. The magnetization directions of the horizontal magnets 72 alternate along the X-axis, while each deflection magnet group 71 comprises multiple sub-magnets 711, each magnetized at an angle to the Z-axis, connected in sequence. This creates a multi-stage, gradually changing magnetic field distribution in the transition region between the horizontal magnets 72 by incorporating the angular magnetization characteristics of the deflection magnet groups 71. The angles between the magnetization directions of the sub-magnets 711 and the Z-axis effectively adjust the direction of the magnetic field vector, transforming the magnetic field variation between the deflection magnet group 71 and adjacent horizontal magnets 72 from a single, abrupt change in direction to a multi-stage, continuous transition. As the coil assembly 6 moves within the magnetic field, the multiple sub-magnets 711 of the deflection magnet group 71, through their staged magnetization angle adjustments, gradually guide the magnetic field direction from the Z-axis toward the X-axis, thereby forming a smooth magnetic field gradient within the air gap region. This magnetic field superposition method not only enhances the uniformity of the magnetic flux density within the effective working area, but also reduces the local magnetic field line distortion caused by sudden changes in the magnetic field direction in the traditional structure. The positive and negative alternating magnetization directions of the horizontal magnet 72 further cooperate with the gradual magnetic field of the deflection magnet group 71, so that the air gap magnetic field forms a highly consistent periodic distribution pattern in the direction of motion of the mover (i.e., the X-axis direction). The electromagnetic thrust generated thereby has a more stable intensity distribution in the spatial dimension, which weakens the periodic thrust fluctuations caused by the discontinuity of the magnetic field. In addition, the segmented design of the multi-sub magnet 711 of the deflection magnet group 71 can more accurately control the magnetic field diffusion path, concentrate more magnetic field energy in the effective action area interlinked with the coil assembly 6, reduce the leakage loss of the edge magnetic flux, and thus improve the magnetic field utilization. In summary, the magnet array 7 structure of the motor, while maintaining the unilateral magnetic concentration characteristics of the Halbach array, achieves the unity of high-stable thrust output and high energy density through multi-segment coordinated control of the magnetic field vector, thereby improving the energy utilization and stability of the linear motor.

[0042] The specific structure and implementation principle of the magnet array 7 are described below.

[0043] The deflection magnet group 71 includes two sub-magnets 711, which are sequentially connected along the distribution direction of the magnet array 7 (i.e., the X-axis). The angle between the magnetization direction of the two sub-magnets 711 in the same deflection magnet group 71 and the Z-axis is a deflection angle θ. The magnetization directions of the two sub-magnets 711 are symmetrically arranged about the Z-axis, and the magnetization directions of two adjacent deflection magnet groups 71 alternate between the positive and negative directions of the Z-axis. For example, for a deflection magnet group 71, if its overall magnetization direction is positive about the Z-axis, the magnetization direction of the first sub-magnet 711 is positive about the Z-axis and deflected to the left by an angle of θ, while the magnetization direction of the second sub-magnet 711 is positive about the Z-axis and deflected to the right by an angle of θ. The two sub-magnets 711 form a complementary left-right deflection distribution with the Z-axis as the axis of symmetry. The overall magnetization directions of two adjacent deflection magnet groups 71 alternate along the positive and negative Z-axis directions. That is, if the overall magnetization direction of the current deflection magnet group 71 is in the positive Z-axis direction, the overall magnetization direction of the next deflection magnet group 71 is in the negative Z-axis direction. Its two sub-magnets 711 are magnetized to the left of the negative Z-axis direction by a deflection angle θ and to the right of the negative Z-axis direction by a deflection angle θ, respectively. This design allows the two sub-magnets 711 within the same deflection magnet group 71 to maintain their alignment along the Z-axis while being symmetrically deflected by a deflection angle θ. This creates a superposition of the bidirectional components of the magnetic field vector, resulting in a gradual deflection of the magnetic field direction within the transition region between the horizontal magnets 72. For example, when the movable coil moves along the X-axis, the X-axis magnetic field of the previous horizontal magnet 72 first generates an upward inclined magnetic field component through the sub-magnet 711 with a left-deflected rotation angle θ, and then further tilts to close to the Z-axis direction through the sub-magnet 711 with a right-deflected rotation angle θ, and finally smoothly transitions to the reverse X-direction magnetic field of the next horizontal magnet 72, making the intensity gradient of the air gap magnetic field in the X-axis direction more uniform.

[0044] In other embodiments, multiple sub-magnets 711 with different deflection angles may be provided within the same deflection magnet assembly 71. For example, three or four sub-magnets 711 may be connected in sequence, and the angle between the magnetization direction of each sub-magnet 711 and the Z-axis may gradually change according to a preset gradient. For example, the magnetization direction of a sub-magnet 711 may gradually tilt from near the Z-axis toward the X-axis, or may be adjusted stepwise in specific angle increments to form a continuously gradient magnetic field deflection path. In this type of design, the number of sub-magnets 711 can be flexibly adjusted based on the required smoothness of the magnetic field transition, and there is no specific limit on the number.

[0045] It should be noted that when the number of sub-magnets 711 increases, the width of a single sub-magnet 711 along the distribution direction of the magnet array 7 (X-axis direction) needs to be reduced accordingly to ensure that the sum of the total width of multiple sub-magnets 711 and the width of a single horizontal magnet 72 is still equal to the preset pole pitch, so as to maintain the periodic arrangement of the magnet array 7 and avoid periodic distortion of the magnetic field caused by changes in the pole pitch.

[0046] Furthermore, for the magnet array 7 located on the upper back iron 1, in the deflection magnet group 71 whose magnetization direction is distributed in the positive direction of the Z-axis, the magnetization directions of the two sub-magnets 711 are tilted outward in a direction away from each other, and the angle between them and the positive direction of the Z-axis is a deflection angle θ. That is, the magnetization directions of the two sub-magnets 711 are tilted to the left and right by a deflection angle θ from the Z-axis positive direction reference line, forming an inverted figure-eight distribution that expands outward from bottom to top. For example, the magnetization direction of the left sub-magnet 711 is in the positive direction of the Z-axis and deflected to the left by a deflection angle θ, while the magnetization direction of the right sub-magnet 711 is in the positive direction of the Z-axis and deflected to the right by a deflection angle θ. The two are symmetrically distributed on both sides of the Z-axis.

[0047] In the deflection magnet group 71, whose magnetization direction is distributed in the opposite direction of the Z-axis, the magnetization directions of the two sub-magnets 711 are tilted inward toward each other, and the angle between them and the negative Z-axis is a deflection angle θ. That is, the magnetization vectors of the two sub-magnets 711 tilt to the left and right by a deflection angle θ from the negative Z-axis baseline, but in the opposite direction of the positive Z-axis group, forming an inverted figure-eight distribution that converges inward from top to bottom. For example, the magnetization direction of the left sub-magnet 711 is in the negative Z-axis direction and deflected to the right by an angle θ, while the magnetization direction of the right sub-magnet 711 is in the negative Z-axis direction and deflected to the left by an angle θ, with the two symmetrically converging toward the center.

[0048] For the magnet array 7 located at the lower back iron 2, in the deflection magnet group 71 whose magnetization direction is distributed in the positive direction of the Z-axis, the magnetization directions of the two sub-magnets 711 are tilted inward in the direction of approaching each other and the angle between them and the positive direction of the Z-axis is the deflection angle θ; that is, the magnetization directions of the two sub-magnets 711 are tilted inward in the direction of approaching each other with the positive direction of the Z-axis as a reference, that is, the magnetization direction of the left sub-magnet 711 is the positive direction of the Z-axis and deflected to the right by the angle θ, and the magnetization direction of the right sub-magnet 711 is the positive direction of the Z-axis and deflected to the left by the angle θ, forming a regular figure-eight distribution that converges inward from bottom to top.

[0049] In the deflection magnet group 71, whose magnetization direction is distributed in the negative direction of the Z-axis, the magnetization directions of the two sub-magnets 711 are tilted outwardly away from each other, and the angle between them and the negative direction of the Z-axis is a deflection angle θ. That is, the magnetization directions of the two sub-magnets 711 are tilted outwardly away from each other with the negative direction of the Z-axis as a reference. Specifically, the magnetization direction of the left sub-magnet 711 is in the negative direction of the Z-axis and deflected to the left by an angle θ, while the magnetization direction of the right sub-magnet 711 is in the negative direction of the Z-axis and deflected to the right by an angle θ, forming a figure-eight distribution that expands outward from top to bottom.

[0050] In summary, the positively diverging magnetic field of the upper back iron 1 and the positively converging magnetic field of the lower back iron 2 jointly enhance the magnetic flux uniformity at the center of the air gap; while the reversely converging magnetic field of the upper back iron 1 and the reversely diverging magnetic field of the lower back iron 2 suppress the edge leakage of magnetic field energy. This symmetrical and complementary magnetic field distribution pattern makes the spatial distribution of electromagnetic thrust in the direction of motion of the mover more continuous. At the same time, the symmetrical offset effect of the magnetic field vectors reduces the periodic fluctuations of the normal force, thereby achieving highly stable and low-loss linear drive performance.

[0051] Regarding the shape of the magnet array 7. The sub-magnets 711 have a rectangular or right-angled trapezoidal cross-section. The deflection magnet assembly 71, comprised of multiple sub-magnets 711, also has a rectangular cross-section. Multiple rectangular sub-magnets 711 can be continuously and tightly aligned along the X-axis to form a rectangular deflection magnet assembly 71. If the sub-magnets 711 are right-angled trapezoids, the hypotenuses of two right-angled trapezoids can be interlocked to form a rectangular deflection magnet assembly 71.

[0052] Preferably, the sub-magnets 711 are rectangular, and any two sub-magnets 711 have the same cross-sectional size. This allows standardized molds and processing techniques to be used during the manufacturing process, simplifying the manufacturing process and reducing production difficulty and cost. When rectangular sub-magnets 711 of the same cross-sectional size are assembled into the deflection magnet group 71, the magnetic field strength and distribution generated by each sub-magnet 711 are relatively consistent, helping to create a more uniform magnetic field distribution within the deflection magnet group 71 and throughout the entire magnet array 7. This reduces electromagnetic force fluctuations caused by an uneven magnetic field, thereby reducing vibration and noise during motor operation and improving motor stability.

[0053] Specifically, the horizontal magnet 72 has a rectangular cross-section and is the same height as the deflection magnet group 71. Together, the horizontal magnet 72 and the deflection magnet group 71 form a rectangular magnet array 7. The same height of the horizontal magnet 72 and the deflection magnet group 71 gives the entire magnet array 7 a uniform structure in the vertical direction, simplifying the internal spatial layout of the motor and ensuring a more compact and precise fit between the magnet array 7 and other motor components, thereby improving the stability of the motor's overall structure. Furthermore, the same height allows the magnetic fields generated by the horizontal magnet 72 and the deflection magnet group 71 to better overlap and synergize in the vertical direction, creating a more uniform and stable magnetic field environment.

[0054] More specifically, the width of the sub-magnets 711 is greater than that of the horizontal magnets 72. This design, by increasing the lateral dimensions of the deflection magnet assembly 71, lengthens the transition path for the magnetic field's direction to deflect from the Z-axis to the X-axis. For example, when the sub-magnets 711 are wider, their tilted magnetization direction gradually adjusts the magnetic field vector over a longer spatial range, further reducing the magnetic field deflection gradient between adjacent horizontal magnets 72 and thereby minimizing thrust fluctuations.

[0055] Under the constraint condition of constant pole pitch, the key structural parameters of the novel Halbach magnet array linear motor provided in this embodiment are three: the deflection angle θ of the magnetization direction of the sub-magnet 711, the first width value ω1 of the sub-magnet 711, and the first height value h of the sub-magnet 711. m The three are coupled with each other to regulate the motor thrust performance (including average thrust and thrust fluctuation).

[0056] The influence of the deflection angle θ on the thrust performance is analyzed as follows.

[0057] Figure 5 For the fixed permanent magnet geometric parameters (ω1=7mm, h m =5.45mm as an example), under the condition of 2.42A continuous current, the average thrust and thrust fluctuation peak-to-peak value of the new Halbach magnet array linear motor change with the deflection angle θ.

[0058] As can be seen from the figure, when the deflection angle θ increases from 0° to 12°, the average thrust increases monotonically to a maximum of 57.25 N. Subsequently, as the deflection angle θ further increases, the average thrust shows a downward trend, and the attenuation rate increases significantly after the deflection angle θ exceeds 20°. At the same time, the peak-to-peak thrust fluctuation shows a monotonically decreasing trend with increasing deflection angle θ.

[0059] In particular, when the deflection angle θ is equal to 0°, the magnet array 7 is a traditional two-segment Halbach magnet array 7 .

[0060] When the deflection angle θ varies between 12 and 16 degrees, the fluctuation range of the average thrust is small. Therefore, in this embodiment, the deflection angle θ is greater than or equal to 12 degrees and less than or equal to 16 degrees. Given the actual processing limitations (the magnetization deflection angle tolerance of the permanent magnet is generally controlled within ±2 degrees), 14 degrees is the optimal deflection angle θ.

[0061] The influence of the first width ω1 of the sub-magnet 711 on the thrust performance is analyzed as follows.

[0062] Figure 6 The influence of the first width value ω1 of the sub-magnet 711 on the electromagnetic thrust characteristics is shown. m =5.45mm, focusing on the coupling effect of the first width ω1 of the sub-magnet 711 on thrust performance. As can be seen from the figure, the average thrust reaches a maximum of 58.62N at ω1 = 8.5mm, and its variation curve exhibits a typical parabolic characteristic. The peak-to-peak thrust fluctuation reaches a minimum of 0.042N at ω1 = 8mm, then rises sharply as ω1 increases.

[0063] It's worth noting that when ω1 increases from 8mm to 8.5mm, while the average thrust increases by 0.27% (0.16N), the peak-to-peak thrust fluctuation increases by 146% (from 0.041N to 0.1N). This highlights the trade-off between thrust density and fluctuation suppression in engineering design. Therefore, in this embodiment, the first width is greater than or equal to 7.5mm and less than or equal to 8.5mm.

[0064] Regarding the first height value h of the sub-magnet 711 m The analysis of the impact on thrust performance is as follows.

[0065] from Figure 7 It can be seen that as the first height value h of the sub-magnet 711 m The increase in the height of the sub-magnet 711 significantly improves the average thrust and reduces the peak-to-peak thrust fluctuation. This is mainly because the increase in the height of the sub-magnet 711 increases the air gap magnetic field strength, thereby increasing the thrust density of the motor. At the same time, a higher height of the sub-magnet 711 helps to improve the uniformity of the magnetic field distribution, reduce magnetic field distortion, and thus reduce thrust fluctuation. However, simply increasing the height of the sub-magnet 711 will also lead to an increase in magnetic leakage. Therefore, regarding the first height value h m The specific value of is not limited here, and needs to be coordinated with the increase of the deflection angle θ and the decrease of the first width value ω1 to optimize the magnetic field distribution and suppress the leakage magnetic effect, thereby achieving coordinated optimization of thrust density and thrust fluctuation.

[0066] Figure 8The no-load airgap flux density characteristics of two coreless permanent magnet linear motors under optimized parameters are demonstrated. The results show that the new Halbach magnet array linear motor proposed in this embodiment, with magnet array 7, has a higher flux density amplitude, with a fundamental amplitude of 0.79 T, a 3.1% improvement over the 0.766 T of the traditional two-stage linear motor.

[0067] Figure 9 The thrust waveforms of two coreless permanent magnet linear motors operating at a continuous current of 2.42A are shown. The magnet array 7 of the novel Halbach magnet array linear motor proposed in this embodiment achieves an average thrust of 58.47N, a 3.1% increase over the traditional two-stage array, which is the same as the increase in the air gap magnetic field described above. Regarding thrust fluctuation, the peak-to-peak thrust fluctuation (0.041N) of the novel Halbach magnet array linear motor proposed in this embodiment increases by only 0.003N compared to the traditional two-stage array, resulting in similar fluctuation levels and a fluctuation coefficient of less than 0.1%. Combined with the significant increase in average thrust, this fluctuation level is acceptable in engineering applications.

[0068] It is worth noting that this embodiment only takes the structure of a linear motor of a certain size as an example, and provides the deflection angle θ, the first width value ω1 of the sub-magnet 711, and the first height value h of the sub-magnet 711. m If the size of the motor changes, the deflection angle θ, the first width value ω1 of the sub-magnet 711 and the first height value h of the sub-magnet 711 m The preferred value of will also change accordingly, and the corresponding structures are also within the scope of protection of this patent.

[0069] The above embodiments merely illustrate the basic principles and features of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel Halbach magnet array linear motor, comprising an upper back iron (1) and a lower back iron (2) arranged opposite to each other, wherein a magnet array (7) is provided on each of the opposing surfaces of the upper back iron (1) and the lower back iron (2), and a coil assembly (6) is provided between the two magnet arrays (7), characterized in that: Each pole pitch of the magnet array (7) includes: A deflection magnet group (71) and a horizontal magnet (72), wherein the deflection magnet group (71) and the horizontal magnet (72) are periodically and alternately distributed according to a Halbach magnet array pattern, the magnetization directions of each two adjacent horizontal magnets (72) are alternately distributed along the positive direction and the reverse direction of the X-axis, and a deflection magnet group (71) is arranged between each two adjacent horizontal magnets (72). The deflection magnet group (71) includes a plurality of sub-magnets (711) connected in sequence, and the magnetization directions of the sub-magnets (711) are arranged at an angle to the Z-axis.

2. The novel Halbach magnet array linear motor according to claim 1, characterized in that: The deflection magnet group (71) comprises two sub-magnets (711) connected in sequence, the angle between the magnetization directions of the two sub-magnets (711) of the same deflection magnet group (71) and the Z axis is a deflection angle θ, and the magnetization directions of the two sub-magnets (711) are symmetrically arranged about the Z axis, and the magnetization directions of two adjacent deflection magnet groups (71) are alternately distributed in the positive direction and the negative direction about the Z axis.

3. The novel Halbach magnet array linear motor according to claim 2, characterized in that: In the magnet array (7) located on the upper back iron (1), in the deflection magnet group (71) whose magnetization direction is distributed in the positive direction of the Z axis, the magnetization directions of the two sub-magnets (711) are tilted outward in a direction away from each other, and the angle between them and the positive direction of the Z axis is the deflection angle θ; in the deflection magnet group (71) whose magnetization direction is distributed in the opposite direction of the Z axis, the magnetization directions of the two sub-magnets (711) are tilted inward in a direction approaching each other, and the angle between them and the negative direction of the Z axis is the deflection angle θ.

4. The novel Halbach magnet array linear motor according to claim 2, characterized in that: In the magnet array (7) located on the lower back iron (2), in the deflection magnet group (71) whose magnetization direction is distributed in the positive direction of the Z axis, the magnetization directions of the two sub-magnets (711) are inclined inwardly in a direction approaching each other, and the angle between them and the positive direction of the Z axis is the deflection angle θ; in the deflection magnet group (71) whose magnetization direction is distributed in the negative direction of the Z axis, the magnetization directions of the two sub-magnets (711) are inclined outwardly in a direction away from each other, and the angle between them and the negative direction of the Z axis is the deflection angle θ.

5. The novel Halbach magnet array linear motor according to claim 2, characterized in that: The deflection angle θ is greater than or equal to 12 degrees and less than or equal to 16 degrees.

6. The novel Halbach magnet array linear motor according to claim 1, characterized in that: The cross-sectional shape of the sub-magnet (711) is a rectangle or a right-angled trapezoid, and the cross-sectional shape of the deflection magnet group (71) composed of a plurality of sub-magnets (711) is a rectangle.

7. The novel Halbach magnet array linear motor according to claim 6, characterized in that: The cross-sectional shape of the horizontal magnet (72) is rectangular, the horizontal magnet (72) and the deflection magnet group (71) have the same height, and the horizontal magnet (72) and the deflection magnet group (71) together constitute the rectangular magnet array (7).

8. The novel Halbach magnet array linear motor according to claim 6, characterized in that: The sub-magnets (711) are rectangular, and any two sub-magnets (711) have the same cross-sectional size.

9. The novel Halbach magnet array linear motor according to claim 8, characterized in that: The width of the sub-magnet (711) is greater than the width of the horizontal magnet (72).

10. The novel Halbach magnet array linear motor according to claim 8, characterized in that: The width of the sub-magnet (711) is a first width value ω1, and the first width value ω1 is greater than or equal to 7.5 mm and less than or equal to 8.5 mm.

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