Brushless motor with thin permanent magnets
By covering the thin permanent magnet of the brushless motor with iron sheets and optimizing the structure, the problem of high cost of rare earth permanent magnets was solved, and the magnetic flux intensity was maintained or increased while the material cost was reduced.
Patent Information
- Application Number
- CN202422859298.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-11-22
AI Technical Summary
In existing brushless motors, the thickness of rare earth permanent magnets determines the magnetic flux intensity. Resources are limited and costs are high, so it is necessary to reduce costs without reducing the number and area of permanent magnets.
A thin permanent magnet is used and an iron sheet is covered on its second side. The iron sheet refracts and guides the magnetic lines of force to enhance the magnetic flux intensity. Combined with different structural designs such as the inner and outer rotors and slot positions, the magnetic flux intensity is ensured not to be weakened.
While maintaining or increasing magnetic flux strength, the cost of permanent magnet materials is reduced by 15-20%, achieving the conservation of rare earth resources.
Smart Images
Figure CN223527866U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of brushless motors, specifically a brushless motor with a thin permanent magnet. Background Technology
[0002] A brushless motor consists of magnets coaxially fixed in the rotor, while the stator is a winding coil.
[0003] by Figure 1 Taking a known brushless motor from the prior art as an example, its structure includes an inner rotor 1' and a winding coil 2' surrounding the inner rotor 1', wherein the inner rotor 1' has an output shaft 11' and an iron core 12' coaxially connected to the output shaft 11'. Figure 1 In the prior art shown, the iron core 12' has multiple slots 13' distributed at equal angular intervals around the output shaft 11', and a permanent magnet 14' is inserted into each slot 13'. The permanent magnets 14' cooperate with each other to magnetize the iron core 12' into the magnet of the inner rotor 1'.
[0004] Obviously, in Figure 1 In the brushless motor structure shown, the magnetic flux intensity of the magnet is determined by the number, area, and thickness of the permanent magnets 14'. Because the permanent magnets 14' always have magnetic leakage, the thickness of the permanent magnets 14' will be proportional to the magnetic flux intensity of the magnet if the number and area of the permanent magnets 14' remain unchanged.
[0005] In existing technologies, rare earth elements are the most important material for permanent magnets. Since rare earth resources are limited, it is necessary to find a brushless motor that can reduce the cost of permanent magnets. Utility Model Content
[0006] The present invention aims to provide an internal rotor brushless motor with thin permanent magnets, which, without changing the number and area of permanent magnets, uses thinner permanent magnets while ensuring that the magnetic flux intensity of the magnets is not weakened.
[0007] To achieve the above objectives, the present invention adopts the following technical solution.
[0008] A brushless motor with a thin permanent magnet includes a rotor and a winding coil that is coaxially coupled to the rotor. The rotor has an output shaft and an iron core coaxially connected to the output shaft. The iron core has multiple slots that are equidistantly distributed around the output shaft, and a permanent magnet is inserted into each slot. The permanent magnet has a first side for engaging with the winding coil and a second side opposite to the first side. The second side is covered with an iron sheet on its end face.
[0009] As an improvement to the above technical solution, the two ends of the iron sheet have folded edges that engage with permanent magnets in a direction parallel to the axial direction of the output shaft.
[0010] As a kind of improvement of the above technical scheme, winding coil ring is arranged at the periphery of iron core.
[0011] Further, the slot is opened in the end face of iron core along the axial direction.
[0012] As another improvement of the above technical scheme, iron core is arranged at the periphery of winding coil.
[0013] Further, the slot is opened in the inner ring surface of iron core.
[0014] Further, the first side of permanent magnet is shaped as arc concave surface, and the arc concave surfaces on each permanent magnet are coaxially matched.
[0015] Compared with prior art, the utility model has following beneficial effects: permanent magnet is refracted and guided by the magnetic force line of second side through iron sheet, so that the magnetic flux intensity of first side is enhanced; therefore, for brushless motor, on the basis of keeping the magnetic flux intensity of rotor magnetic steel unchanged or improving, comparatively thinner permanent magnet than prior art can be used, and the material cost of permanent magnet can be reduced by 15-20%.
[0016] Next, the utility model is further explained in combination with the drawings and specific embodiments in the specification. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is a structural schematic view of brushless motor known in prior art.
[0018] Figure 2 It is a structural schematic view of embodiment one of the utility model.
[0019] Figure 3 It is an assembly schematic view of permanent magnet in embodiment one of the utility model.
[0020] Figure 4 It is a structural schematic view of embodiment two of the utility model.
[0021] Figure 5 It is an assembly schematic view of permanent magnet in embodiment two of the utility model.
[0022] Figure 6 It is a structural schematic view of embodiment three of the utility model. DETAILED DESCRIPTION
[0023] Please refer to Figure 2 、 Figure 4As shown in the utility model provides a kind of brushless motor with thin permanent magnet, including rotor 1, and the winding coil 2 of coaxial cooperation with rotor 1, rotor 1 has output shaft 11, coaxial connection on output shaft 11 The core 12, the core 12 is equipped with multiple insertion slots 13 around output shaft 11 equiangular distance distribution, and one permanent magnet 14 is respectively implanted in insertion slot 13;Permanent magnet 14 has the first side for cooperation winding coil 2, the second side opposite to the first side, and second side is covered with iron sheet 15 on end face.
[0024] As Figure 3 And Figure 5 As shown, the magnetic force line of permanent magnet 14 is refracted and guided to the second side by iron sheet 15, so that the magnetic flux intensity of the first side is enhanced;Therefore, for brushless motor, on the basis of keeping the magnetic flux intensity of rotor 1 magnetic steel unchanged or improving, relatively thinner permanent magnet 14 can be used compared with prior art, and the material cost of permanent magnet 14 can be reduced by 15-20%.
[0025] The utility model provides the following embodiment to further explain the improvement point.
[0026]
Embodiment one
[0027] As Figure 2 And Figure 3 As shown in embodiment one, the brushless motor with thin permanent magnet 14 includes rotor 1, and the winding coil 2 of coaxial cooperation with rotor 1, rotor 1 has output shaft 11, coaxial connection on output shaft 11 The core 12, the core 12 is equipped with multiple insertion slots 13 around output shaft 11 equiangular distance distribution, and one permanent magnet 14 is respectively implanted in insertion slot 13;Permanent magnet 14 has the first side for cooperation winding coil 2, the second side opposite to the first side, and second side is covered with iron sheet 15 on end face.
[0028] Among them, iron sheet 15 is magnetically connected with permanent magnet 14, or bonded.
[0029] Among them, winding coil 2 is arranged around the periphery of core 12, that is, embodiment one is a kind of inner rotor 1 brushless motor.
[0030] Preferably, insertion slot 13 is arranged on the end face of core 12 along the axial direction.
[0031]
Embodiment two
[0032] As Figure 4 And Figure 5As shown in the embodiment two, the brushless motor with the thin permanent magnet 14 comprises a rotor 1, a winding coil 2 coaxially matched with the rotor 1, the rotor 1 has an output shaft 11, a coaxial iron core 12 connected on the output shaft 11, the iron core 12 is provided with a plurality of slots 13 distributed at equal angles around the output shaft 11, and each slot 13 is implanted with a permanent magnet 14; the permanent magnet 14 has a first side for matching the winding coil 2, and a second side opposite to the first side, and the second side is covered with an iron sheet 15 on an end face.
[0033] Wherein, the iron core 12 is annularly arranged at the periphery of the winding coil 2, that is, the embodiment two is an outer rotor 1 brushless motor.
[0034] Preferably, the slot 13 is arranged on the inner annular surface of the iron core 12.
[0035] Further, the first side of the permanent magnet 14 is shaped as an arc-shaped concave surface, and the arc-shaped concave surfaces on each permanent magnet 14 are coaxially matched.
[0036]
Embodiment three
[0037] As shown in the embodiment three, the iron sheet 15 is provided with a folded edge 16 for buckling the permanent magnet 14 at each end in the direction parallel to the axial direction of the output shaft 11. Figure 6 Due to the arrangement of the folded edge 16, the iron sheet 15 is more easily combined with the permanent magnet 14 accurately, and the refraction of the magnetic force line can be strengthened through the folded edge 16, so that the magnetic flux intensity of the first side is further enhanced.
[0038] Obviously, the embodiment three can be applied to the embodiment one and the embodiment two.
[0039] In order to more intuitively reflect the beneficial effects of the utility model, the applicant has carried out sample test, and the test data is as follows.
[0040]
[0041] The above comparative examples 1 to 4 adopt the same brushless motor, and only the size of the permanent magnet and whether the iron sheet is arranged on the end face of the second side of the permanent magnet are different in different comparative examples.
[0042] Wherein:
[0043] The comparative example 1 adopts the original permanent magnet of the same brushless motor, and the thickness of the original permanent magnet is 2mm;
[0044] The comparative example 2 replaces the original permanent magnet with a thin permanent magnet with a reduced thickness on the basis of the comparative example 1, and the thickness of the thin permanent magnet is 1.5mm;
[0045] The second side of the thin permanent magnet in Comparative Example 3 is covered with an iron sheet on the end face on the basis of Comparative Example 2, the thickness of the iron sheet is 0.5 mm, so that the overall size of the thin permanent magnet after covering the iron sheet is the same as that of the original permanent magnet;
[0046] The width of the thin permanent magnet in Comparative Example 4 is reduced on the basis of Comparative Example 3, and the iron sheet is arranged in Example 3, so that the overall size of the thin permanent magnet after covering the iron sheet is the same as that of the original permanent magnet.
[0047] The test data of the above comparative examples show that even if the thin permanent magnet is used, the highest surface magnetism and the center surface magnetism of the rotor magnetic steel can be close to or even higher than the data of using the original permanent magnet, and the brushless motor can reach the expected rotating speed. Obviously, in the large-scale industrial production application, the material cost of the permanent magnet can be effectively reduced.
[0048] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, the scope of the utility model is defined by the appended claims and their equivalents.
Claims
1. A brushless motor with thin permanent magnets, comprising a rotor, a winding coil coaxially matched with the rotor, the rotor having an output shaft, a coaxial iron core connected to the output shaft, a plurality of insertion slots being formed on the iron core and distributed at equal angular intervals around the output shaft, and one permanent magnet being respectively implanted in each insertion slot; characterized in that, The permanent magnet has a first side for matching the winding coil, a second side opposite to the first side, and the second side is covered with an iron sheet on an end face.
2. The brushless motor with thin permanent magnets according to claim 1, characterized in that, In a direction parallel to the axial direction of the output shaft, the two ends of the iron sheet are respectively provided with a folded edge for buckling the permanent magnet.
3. The brushless motor with thin permanent magnets according to claim 1 or 2, characterized in that, The winding coil is annularly arranged on the periphery of the iron core.
4. The brushless motor with thin permanent magnets according to claim 3, characterized in that, The slot is opened on the end face of the iron core along the axial direction.
5. The brushless motor with thin permanent magnets according to claim 1 or 2, characterized by, The iron core is annularly arranged on the periphery of the winding coil.
6. The brushless motor with thin permanent magnets according to claim 5, characterized in that, The slot is opened on the inner annular face of the iron core.
7. The brushless motor with thin permanent magnets according to claim 6, characterized in that, The first side of the permanent magnet is shaped as an arc-shaped concave surface, and the arc-shaped concave surfaces on the permanent magnets are coaxially matched.