Mover assembly and permanent magnet linear motor

Abstract

The application provides a mover assembly and a permanent magnet linear motor, the mover assembly has a length direction, a width direction and a height direction which are perpendicular to each other, the mover assembly comprises a plurality of movers which are arranged side by side along the length direction, windings are arranged on the movers, and the thickness direction of the mover is the same as the length direction; in the width direction, the thickness of the middle part of the mover is greater than the thickness of the two ends of the mover. That is, the mover in the scheme is not a conventional structure with a constant thickness, but a structure with a thick middle part and thin two ends. The mover can also be understood as a structure with multiple unequal thicknesses which are stacked together. In this way, the positioning force of each segment structure is at a different phase, compared with the conventional structure with a constant thickness, the wave peaks and wave troughs generated by each segment structure are reduced after superposition, thereby reducing the positioning force. When the mover assembly is applied to the permanent magnet linear motor, the positioning force of the permanent magnet linear motor is reduced, and the performance of the permanent magnet linear motor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a mover assembly and a permanent magnet linear motor. BACKGROUND

[0002] The permanent magnet linear motor has a simple structure and rapid start and stop, and is widely used in the fields of machine tools and transportation. However, the permanent magnet synchronous linear motor does not have the closed circular shape of the rotating motor, but has a flat core at both ends, so that the magnetic flux distribution at both ends is different from that of the middle part. Not only is the magnetic field weak, but also serious distortion occurs, resulting in end force. The end force and the cogging force are coupled to form the positioning force of the permanent magnet linear motor, and the excessive positioning force affects the performance of the motor. Therefore, how to reasonably design a permanent magnet linear motor with low positioning force has become a difficult problem to be solved in the industry. SUMMARY

[0003] The present application provides a mover assembly and a permanent magnet linear motor to solve the problem of large positioning force of the permanent magnet linear motor in the prior art.

[0004] In order to solve the above problems, the present application provides a mover assembly for a permanent magnet linear motor, the mover assembly having a length direction, a width direction and a height direction perpendicular to each other, the mover assembly comprising a plurality of mover teeth arranged side by side along the length direction, the mover teeth being provided with windings thereon, and the thickness direction of the mover teeth being in the same direction as the length direction; in the width direction, the thickness of the middle part of the mover teeth is greater than the thickness of the two ends of the mover teeth.

[0005] Further, the opposite sides of the mover teeth are respectively provided with a first V-shaped side and a second V-shaped side, and the first V-shaped side and the second V-shaped side are oppositely arranged.

[0006] Further, the first V-shaped side has a first inclined surface and a second inclined surface connected to each other, and the second V-shaped side has a third inclined surface and a fourth inclined surface connected to each other, wherein the included angle θ between the first inclined surface, the second inclined surface, the third inclined surface and the fourth inclined surface and the width direction is equal.

[0007] Further, θ = actan (τ / l / n / 2) to eliminate n-th harmonic, wherein τ is the pole pitch, the mover assembly comprises a plurality of stacked silicon steel sheets, and l is the stacking size of the silicon steel sheets in the width direction.

[0008] Further, the mover assembly further comprises two end teeth, and a plurality of the mover teeth are located between the two end teeth; in the width direction, the end tooth comprises a plurality of end sections connected in sequence; and adjacent two end sections are arranged in a staggered manner in the length direction.

[0009] Further, the plurality of end sections comprises a first end section, a middle end section and a second end section connected in sequence, the middle end section is staggered relative to the first end section in a direction away from the mover tooth by a distance L1, and the middle end section is staggered relative to the second end section in a direction away from the mover tooth by a distance L2, wherein τ / 5≤L1≤τ / 3, τ / 5≤L2≤τ / 3, and τ is the pole pitch.

[0010] Further, in the height direction, the mover tooth has an arc surface towards one end of a stator assembly of the permanent magnet linear motor, and the convex direction of the arc surface is towards the stator assembly.

[0011] Further, the minimum air gap between the arc surface and the stator assembly is 0.5mm-0.7mm.

[0012] Further, at least one auxiliary slot is arranged on the arc surface.

[0013] Further, the depth of the auxiliary slot is Hs, 0.5mm<Hs<2mm; and / or,

[0014] The size of the auxiliary slot in the thickness direction of the mover tooth is Bs, 0.5mm<Bs<2mm; and / or,

[0015] At least two auxiliary slots are arranged on the arc surface in the thickness direction of the mover tooth, and the distance between adjacent two auxiliary slots is 3mm-4mm.

[0016] According to another aspect of the present application, a permanent magnet linear motor is provided, which comprises a stator assembly and the above-mentioned mover assembly, and the magnetic steel in the stator assembly is magnetized in a Halbach array magnetization mode.

[0017] Further, the magnetic steel in the stator assembly comprises a plurality of horizontal magnetization sections and a plurality of vertical magnetization sections distributed along the length direction, two horizontal magnetization sections are arranged between adjacent two vertical magnetization sections, the magnetization direction in the vertical magnetization section is upward or downward, and the magnetization directions of the two horizontal magnetization sections on both sides of the vertical magnetization section are towards each other or away from each other; in the length direction, the sum of the lengths of the plurality of vertical magnetization sections is not less than 0.3 times the length of the mover assembly.

[0018] The technical scheme of the application provides a mover assembly used in a permanent magnet linear motor, the mover assembly has a length direction, a width direction and a height direction which are perpendicular to each other, the mover assembly comprises a plurality of mover teeth which are arranged side by side along the length direction, the mover teeth are used for winding windings, and the thickness direction of the mover teeth is the same as the length direction; in the width direction, the thickness of the middle part of the mover teeth is greater than the thickness of the two ends of the mover teeth. That is, the mover teeth in the technical scheme are not the conventional structure with constant thickness, but the structure with thick middle part and thin two ends, the mover teeth can also be understood as being formed by stacking a plurality of unequal-thickness structures, so that the positioning forces of the structures are at different phases, compared with the conventional structure with constant thickness, the wave peaks and wave troughs generated by the structures are reduced after superposition, so that the positioning force is reduced. The mover assembly is applied to the permanent magnet linear motor, the positioning force of the permanent magnet linear motor is reduced, and the performance of the permanent magnet linear motor is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the application, and together with the description of the application, serve to explain the application. In the drawings:

[0020] Figure 1 A perspective view of the mover assembly provided by the embodiment of the application is shown in the figure;

[0021] Figure 2 A bottom view of the mover assembly in the figure is shown; Figure 1

[0022] A front view of the mover assembly in the figure is shown; Figure 3 Figure 1 A partial enlarged view of the mover assembly in the figure at position A is shown;

[0023] Figure 4 Figure 1 A schematic diagram of the magnetizing direction of the stator assembly in the permanent magnet linear motor provided by the embodiment of the application is shown;

[0024] Figure 5 A top view of the stator assembly in the permanent magnet linear motor provided by the embodiment of the application is shown.

[0025] Figure 6 The above drawings comprise the following reference signs:

[0026] In the drawings, the following reference signs are used:

[0027] 10, mover tooth;

[0028] 11, first inclined surface;

[0029] 12, second inclined surface;

[0030] 13, third inclined surface;​​

[0031] 14. fourth inclined surface;

[0032] 15. arc surface;

[0033] 16. auxiliary groove;

[0034] 20. end tooth;

[0035] 21. first end section;

[0036] 22. middle end section;

[0037] 23. second end section;

[0038] 30. stator assembly;

[0039] 31. horizontal magnetizing section;

[0040] 32. vertical magnetizing section. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0042] As shown in Figures 1 to 4 the embodiments of the present application provide a mover assembly for a permanent magnet linear motor, the mover assembly has length direction, width direction and height direction perpendicular to each other, the mover assembly comprises a plurality of mover teeth 10 arranged side by side along the length direction, the mover teeth 10 are used for winding windings, the thickness direction of the mover teeth 10 is the same as the length direction; in the width direction, the thickness of the middle part of the mover teeth 10 is greater than the thickness of the two ends of the mover teeth 10.

[0043] That is, the mover teeth 10 in the present scheme are not the conventional structure with constant thickness, but the structure with thick middle part and thin two ends, the mover teeth 10 can also be understood as being stacked by a plurality of unequal-thickness structures, so that the positioning forces of the structures are at different phases, compared with the conventional structure with constant thickness, the wave peaks and wave troughs generated by the structures are reduced after superposition, thereby reducing the positioning force. The mover assembly is applied to the permanent magnet linear motor, thereby reducing the positioning force of the permanent magnet linear motor and improving the performance of the permanent magnet linear motor.

[0044] As shown in Figure 2As shown, the mover tooth 10 has a first V-shaped side and a second V-shaped side on opposite sides, and the first V-shaped side and the second V-shaped side are oppositely arranged. The included angle of the first V-shaped side and the included angle of the second V-shaped side can be the same or different.

[0045] The tooth shape is arranged to help optimize the distribution of magnetic lines, so that the distribution of magnetic lines in the tooth part is more uniform, thereby reducing the attraction or repulsion force of the magnetic force on the mover, and reducing the positioning force.

[0046] Specifically, the first V-shaped side has a first inclined surface 11 and a second inclined surface 12 connected to each other, and the second V-shaped side has a third inclined surface 13 and a fourth inclined surface 14 connected to each other, wherein the included angle θ between the first inclined surface 11, the second inclined surface 12, the third inclined surface 13 and the fourth inclined surface 14 and the width direction is equal.

[0047] In this way, the first inclined surface 11 and the third inclined surface 13 are symmetrical, and the second inclined surface 12 and the fourth inclined surface 14 are symmetrical. The mover tooth 10 is stacked by silicon steel sheets, and through the above arrangement, the machining and assembly of the mover tooth 10 are facilitated.

[0048] In the motor, the n-th harmonic refers to the harmonic component of the motor stator current or stator voltage, and its frequency is an integer multiple of the fundamental frequency. Harmonics are a common phenomenon in AC power systems, which are caused by non-sinusoidal waveforms generated by motors, transformers, generators and other equipment during operation.

[0049] Harmonics in the motor can cause a variety of problems, including but not limited to: harmonic currents can increase motor losses, causing the motor temperature to rise, affecting the motor's heat dissipation and life; harmonic currents can cause mechanical vibration of the motor, increasing noise; harmonic currents can affect the efficiency of the motor, causing energy waste; harmonic currents can cause electromagnetic interference, affecting the normal operation of other electrical equipment.

[0050] Suppose the mover tooth 10 is divided into N segments of unequal thickness, and the inclination angle θ of each inclined surface can be referred to the following formula:

[0051]

[0052] In order to eliminate the n-th harmonic, the inclination angle is

[0053] That is, the mechanical angle of inclination is θ = actan (τ / l / n / 2), where τ is the pole pitch, the mover assembly includes a plurality of stacked silicon steel sheets, and l is the stacking size of the silicon steel sheet in the width direction.

[0054] For example, Figure 1 and Figure 2As shown, the mover assembly further comprises two end teeth 20, and the plurality of mover teeth 10 are located between the two end teeth 20; in the width direction, the end teeth 20 comprise a plurality of end sections connected in sequence; and adjacent two end sections are arranged in a staggered manner in the length direction.

[0055] In this way, the end teeth 20 are in a multi-section staggered structure, which can effectively weaken the harmonic wave, and this method can more fully consider the coupling of the end force and the slot force in the end teeth 20, thereby reducing the detent force.

[0056] The end force calculation formula is as follows:

[0057]

[0058] Wherein, Δ=L-kτ, L is the longitudinal length of the linear motor, τ is the pole pitch, and k is an integer.

[0059] In one specific embodiment, the plurality of end sections comprise a first end section 21, a middle end section 22 and a second end section 23 connected in sequence, the middle end section 22 is staggered relative to the first end section 21 in a direction away from the mover teeth 10, and the staggered distance is L1, and the middle end section 22 is staggered relative to the second end section 23 in a direction away from the mover teeth 10, and the staggered distance is L2.

[0060] In actual application, the number and distance of the sections can be adjusted according to the number of harmonic waves to be eliminated.

[0061] For example, τ / 5≤L1≤τ / 3, τ / 5≤L2≤τ / 3, and τ is the pole pitch.

[0062] As shown in FIGS. 1 and 2, Figure 3 and Figure 4 As shown, in the height direction, the mover teeth 10 have an arc surface 15 at one end facing the stator assembly 30 of the permanent magnet linear motor, and the convex direction of the arc surface 15 faces the stator assembly 30.

[0063] With the above arrangement, the arc surface 15 makes the air gap of the linear motor not equal in length, and the air gap magnetic density is closer to a sine, thereby optimizing the air gap magnetic density and reducing the detent force.

[0064] In one specific embodiment, the minimum air gap between the arc surface 15 and the stator assembly 30 is 0.5mm-0.7mm. In actual design and production, the air gap can be adjusted appropriately according to the actual mechanical assembly precision to avoid affecting assembly.

[0065] Further, at least one auxiliary slot 16 is arranged on the arc surface 15. The auxiliary slot 16 can reduce the slot force. The design of the auxiliary slot can help balance the magnetic circuit of the mover and reduce the uneven distribution of magnetic flux between the teeth and the slots, thereby reducing the generation of the slot force.

[0066] Wherein, the depth of the auxiliary groove 16 is Hs, 0.5mm < Hs < 2mm; and / or, the dimension of the auxiliary groove 16 in the thickness direction of the moving tooth 10 is Bs, 0.5mm < Bs < 2mm; and / or, at least two auxiliary grooves 16 spaced apart in the thickness direction of the moving tooth 10 are provided on the arc-shaped surface 15, and the distance between two adjacent auxiliary grooves 16 is 3mm to 4mm.

[0067] The above settings can effectively reduce the cogging force while ensuring the mechanical strength of the moving tooth 10.

[0068] like Figure 5 and Figure 6 As shown, another embodiment of the present invention provides a permanent magnet linear motor, which includes a stator assembly 30 and the aforementioned mover assembly. The magnets in the stator assembly 30 are magnetized using a Hellbeck array magnetization method. This magnetization method can effectively improve the air gap magnetic flux density.

[0069] Specifically, the magnets in the stator assembly 30 include multiple horizontal magnetized sections 31 and multiple vertical magnetized sections 32 distributed along the length direction. Two horizontal magnetized sections 31 are arranged between two adjacent vertical magnetized sections 32. The magnetization direction in the vertical magnetized section 32 is upward or downward. The magnetization directions in the two horizontal magnetized sections 31 on both sides of the vertical magnetized section 32 are facing each other or away from each other. In the length direction, the sum of the lengths of the multiple vertical magnetized sections 32 is not less than 0.3 times the length of the mover assembly.

[0070] By implementing the above settings, magnetic leakage can be effectively reduced, thereby improving the utilization rate of the magnet.

[0071] like Figure 5 As shown, in one specific embodiment, a three-stage magnetization method is adopted, with the magnetization directions from left to right being: horizontal to the right, vertical to the up, horizontal to the left, horizontal to the left, vertical to the down, and horizontal to the right. Since the length ratio of different magnetization directions affects the magnetic circuit direction, it is necessary to ensure that the width of the vertically up and vertically down directions is not less than 0.3 times the total width of the magnet, while the remaining width is evenly distributed between the horizontally left and horizontally right directions. This design adopts a magnetization ratio of 1:3:1:1:3:1 to obtain the maximum air gap magnetic flux density.

[0072] After magnetization, the surface of the magnet is phosphated to ensure its corrosion resistance and the bonding strength between the magnet and the magnetic plate.

[0073] The above scheme has the following beneficial effects:

[0074] The mover tooth 10 is a structure of thick in the middle and thin at both ends, and can also be understood as a structure of multiple segments with different thicknesses stacked together, so that the positioning force of each segment structure is at different phases, compared with the conventional structure with constant thickness, the wave peaks and troughs generated by each segment structure are reduced after superposition, thereby reducing the positioning force.

[0075] The end tooth 20 is a structure of multiple segments with misalignment, which can effectively weaken the harmonic, and this method can more fully consider the coupling of the end force and the tooth slot force in the end tooth 20, thereby reducing the positioning force.

[0076] By setting the arc surface 15, the air gap of the linear motor is not equal in length, and the air gap magnetic density is closer to sine, thereby optimizing the air gap magnetic density and reducing the positioning force.

[0077] By setting the auxiliary slot 16 at the end of the mover tooth 10, the tooth slot force can be reduced.

[0078] By using the above scheme, the positioning force of the permanent magnet linear motor is reduced, and the performance of the permanent magnet linear motor is improved.

[0079] The above only describes optional embodiments of the present scheme and is not intended to limit the present scheme. For those skilled in the art, the present scheme can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present scheme shall be included in the protection scope of the present scheme.

[0080] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that the terms "comprise" and / or "include" as used in the specification indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0081] Unless otherwise specifically stated, the relative arrangement of parts and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present scheme. At the same time, it should be understood that the sizes of the various parts shown in the drawings are not drawn in proportion to the actual proportions. The techniques, methods and devices known to those skilled in the relevant art can not be discussed in detail, but under appropriate circumstances, the techniques, methods and devices should be considered as part of the specification. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0082] In the description of the present solution, it needs to be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship is generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present solution and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element indicated must have a particular orientation or be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the scope of protection of the present solution; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component itself.

[0083] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0084] In addition, it needs to be pointed out that the use of "first", "second" and the like to define parts only for the convenience of distinguishing the corresponding parts, and if there is no further declaration, the above words have no special meaning, therefore cannot be understood as a limitation on the scope of protection of the present solution.

Claims

1. A mover assembly for a permanent magnet linear motor, the mover assembly having a length direction, a width direction and a height direction perpendicular to each other, characterized by, The mover assembly comprises a plurality of mover teeth (10) arranged side by side along the length direction, the mover teeth (10) are provided with windings, and the thickness direction of the mover teeth (10) is the same as the length direction; in the width direction, the thickness of the middle part of the mover teeth (10) is greater than the thickness of the two ends of the mover teeth (10); The opposite sides of the mover teeth (10) are respectively provided with a first V-shaped side and a second V-shaped side, the first V-shaped side is provided with a first inclined surface (11) and a second inclined surface (12) connected with each other, and the second V-shaped side is provided with a third inclined surface (13) and a fourth inclined surface (14) connected with each other, wherein the included angle θ between the first inclined surface (11), the second inclined surface (12), the third inclined surface (13) and the fourth inclined surface (14) and the width direction is equal; θ = actan (τ / l / n / 2), so as to eliminate n-th harmonic, wherein τ is the pole pitch, the mover assembly comprises a plurality of stacked silicon steel sheets, and l is the stacking size of the silicon steel sheets in the width direction; The mover assembly further comprises two end teeth (20), in the width direction, the end tooth (20) comprises a plurality of end sections connected in sequence; a plurality of the end sections comprise a first end section (21), a middle end section (22) and a second end section (23) connected in sequence, the middle end section (22) is offset relative to the first end section (21) in a direction away from the mover teeth (10) and the offset distance is L1, and the middle end section (22) is offset relative to the second end section (23) in a direction away from the mover teeth (10) and the offset distance is L2, wherein τ / 5≤L1≤τ / 3 and τ / 5≤L2≤τ / 3, and τ is the pole pitch.

2. The mover assembly of claim 1, wherein, The first V-shaped side and the second V-shaped side are oppositely arranged.

3. The mover assembly of claim 1, wherein, A plurality of the mover teeth (10) are located between the two end teeth (20).

4. The mover assembly of claim 1, wherein, In the height direction, the mover teeth (10) have an arc surface (15) at one end of the stator assembly (30) of the permanent magnet linear motor, and the convex direction of the arc surface (15) is towards the stator assembly (30).

5. The mover assembly of claim 4, wherein, The minimum air gap between the arc surface (15) and the stator assembly (30) is 0.5mm~0.7mm.

6. The mover assembly of claim 4, wherein, At least one auxiliary groove (16) is arranged on the arc surface (15).

7. The mover assembly according to claim 6, wherein, The depth of the auxiliary groove (16) is Hs, and 0.5mm<Hs<2mm; and / or, The size of the auxiliary groove (16) in the thickness direction of the mover teeth (10) is Bs, and 0.5mm<Bs<2mm; and / or, At least two auxiliary grooves (16) are arranged on the arc surface (15) in the thickness direction of the mover teeth (10) and are spaced apart, and the distance between adjacent two auxiliary grooves (16) is 3mm~4mm.

8. A permanent magnet linear motor, characterized by The permanent magnet linear motor comprises a stator assembly (30) and the mover assembly according to any one of claims 1 to 7, and the magnetic steel in the stator assembly (30) is magnetized in a Halbach array.

9. The permanent magnet linear motor according to claim 8, characterized in that The magnetic steel in the stator assembly (30) comprises a plurality of horizontal magnetization segments (31) and a plurality of vertical magnetization segments (32) distributed along the length direction, two horizontal magnetization segments (31) are arranged between two adjacent vertical magnetization segments (32), the magnetization direction in the vertical magnetization segment (32) is upward or downward, and the magnetization directions of the two horizontal magnetization segments (31) on the two sides of the vertical magnetization segment (32) are towards each other or away from each other; in the length direction, the sum of the lengths of the plurality of vertical magnetization segments (32) is not less than 0.3 times the length of the mover assembly.

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