Brushless motor rotor of food processor and food processor

Abstract

The invention relates to the technical field of food processor motors, in particular to a brushless motor rotor of a food processor and the food processor, the rotor comprises an outer permanent magnet, a lining insert and a rotating shaft which are sequentially nested from outside to inside, the lining insert is fixedly connected with the rotating shaft through injection molding, the outer permanent magnet is fixedly connected with the lining insert through injection molding, and the outer permanent magnet is fixedly connected with the lining insert through injection molding. Anti-deformation holes are formed in the end faces of the two sides of the lining insert and extend in the axial direction of the rotating shaft, an insert inner layer is formed between the anti-deformation holes and the rotating shaft, and an insert outer layer is formed between the anti-deformation holes and the outer-layer permanent magnet; the radial thickness of the insert inner layer located at the bottom end of the anti-deformation hole is larger than the radial thickness of the insert inner layer located at the opening end of the anti-deformation hole in the end face of the lining insert. The expansion binding force of the insert inner layer and the rotating shaft is enhanced, and the binding stability of the lining insert and the rotating shaft is improved. And the insert outer layer can be in concave-convex fit with the outer-layer permanent magnet when the outer-layer permanent magnet is subjected to injection molding, so that the outer-layer permanent magnet and the lining insert are combined more tightly.

Description

Technical Field

[0001] This application belongs to the field of motor technology for food processing machines, and particularly relates to a brushless motor rotor for use in food processing machines and a food processing machine. Background Technology

[0002] Currently, most mainstream low-noise food processing machines use permanent magnet brushless motors. The motor structure consists of a rotor assembly, a stator assembly, and a housing, arranged sequentially from the inside out. The stator assembly includes a stator core, stator windings, and a stator frame. The stator frame is mounted on the stator core, and the stator windings are wound around the stator frame.

[0003] For rotor assemblies using injection molding, they typically include a motor shaft, injection-molded inserts, injection-molded magnets, and a cooling fan. The injection-molded inserts and magnets of the rotor structure are injection-molded sequentially. The injection-molded inserts are integrated with the motor shaft through injection molding, while the injection-molded magnets are formed around the injection-molded inserts, simplifying the assembly process. However, the stability of the connection between the injection-molded inserts and the motor shaft remains a crucial consideration. Patent application CN201620881511.3 discloses a plastic magnetic rotor for a DC motor, comprising a rotor body with a cylindrical structure and a matching component with an annular cross-section. The rotor body has annular positioning grooves at both ends for engaging with the DC motor spindle, and a through rotor shaft hole at its center. The matching component is fitted around the outer circumference of the rotor body, with its inner diameter slightly larger than the radius of the rotor body. The inner wall of the matching component has a receiving groove for accommodating a magnetic ring. The inner wall of the matching component and the outer wall of the rotor body can be connected by injection molding. The inner wall of the annular positioning groove is inclined. By flexibly selecting appropriate-sized magnetic rings and matching components to install on the outer circumference of the rotor body according to the required magnetic strength, the motor's adaptability is greatly enhanced. However, this design presents a problem: the tilted positioning groove is susceptible to concentrated stress from the motor as it moves outwards. This is particularly problematic in food processing machines, where the complex fluid environment and varying loads during the crushing process can lead to significant rotor wear and even damage. Furthermore, stress concentration and cracking can occur during rotor manufacturing, resulting in substandard production batches. If these substandard products are not detected and installed in the food processing machine, it poses serious performance and safety risks.

[0004] To address the technical problem of cracking easily in the double-layer plastic magnetic rotor of brushless motors, patent application CN201620652669.3 discloses a plastic magnetic ring. The central shaft of the plastic magnetic ring passes through a rotor shaft hole, and an annular groove is provided between the plastic magnetic ring and the rotor shaft hole. Two symmetrically distributed fan-shaped positioning holes are also provided within the annular groove, with an arc of 90°. This positioning hole design allows for engagement with the convex surfaces of other components. To improve the wear resistance of the plastic magnetic ring, a plastic wear-resistant layer is injection-molded onto the inner wall of the rotor shaft hole, with one end of the plastic wear-resistant layer extending beyond the meshing surface of the plastic magnetic ring. The selected plastic wear-resistant layer is made of polyoxymethylene resin, which has good wear resistance and high rigidity. This prevents the plastic magnetic ring from wearing and cracking during rotor shaft rotation, thus avoiding damage to the rotor shaft. By setting two symmetrically distributed cylindrical clamps between the annular groove and the plastic magnetic ring, the meshing strength between components is further improved, preventing loosening and extending the service life of each component. However, while the use of annular grooves and positioning holes can improve wear resistance to some extent and prevent jamming caused by wear through wear-resistant materials, it still cannot overcome the problem of cracking caused by stress concentration at the annular grooves. Furthermore, in food processing machines with heating conditions, the issue is not limited to rotor processing; in heating and pulverizing scenarios, the performance requirements for the motor rotor are even higher, and the rotor cracking problem remains unresolved. Summary of the Invention

[0005] The purpose of this invention is to provide a brushless motor rotor for a food processing machine and a food processing machine. In processing scenarios involving heating and crushing hard materials with large load variations, the rotor is prone to thermal expansion and deformation, resulting in stress concentration and cracking at the double-layer plastic magnetic connection and insert layer, leading to motor damage and processing abnormalities.

[0006] To address the aforementioned technical problems, this invention provides a brushless motor rotor for a food processing machine, comprising an outer permanent magnet, an inner insert, and a rotating shaft nested sequentially from the outside to the inside. The inner insert is fixedly connected to the rotating shaft via injection molding, and the outer permanent magnet is fixedly connected to the inner insert via injection molding. Anti-deformation holes are provided on both end faces of the inner insert, extending axially along the rotating shaft. An inner insert layer is formed between the anti-deformation holes and the rotating shaft, and an outer insert layer is formed between the anti-deformation holes and the outer permanent magnet. The radial thickness of the inner insert layer at the bottom of the anti-deformation hole is greater than the radial thickness of the inner insert layer at the opening end of the anti-deformation hole on the end face of the inner insert. The inner insert layer has a first side facing the anti-deformation hole, and the outer insert layer has a second side facing the anti-deformation hole. The second side extends from the bottom of the anti-deformation hole to the opening end on the end face of the inner insert, and the second side is parallel to the axial direction of the rotating shaft.

[0007] Furthermore, the first side is inclined from the bottom end of the anti-deformation hole toward the rotating shaft, and the first side is an inclined surface or an arc surface.

[0008] Furthermore, multiple anti-deformation holes are provided on both end faces of the inner lining insert, and the anti-deformation holes on both sides are arranged opposite each other along the axial direction of the rotating shaft.

[0009] Furthermore, multiple anti-deformation holes on each side are equally spaced around the rotating shaft.

[0010] Furthermore, a partition is provided between the anti-deformation holes on both sides, and the partition separates the anti-deformation holes on both sides.

[0011] Furthermore, the inner insert has a central hole extending axially along the rotating shaft, the central hole connecting the anti-deformation holes on both sides; an intermediate inner layer is formed between the central hole and the rotating shaft, the radial thickness of the intermediate inner layer being greater than the maximum radial thickness of the insert inner layer.

[0012] Furthermore, an intermediate outer layer is formed between the intermediate hole and the outer permanent magnet. The intermediate outer layer has an intermediate outer side facing the intermediate hole, and the insert outer layer has a second side facing the anti-deformation hole. The second side is flush with the intermediate outer side, or the intermediate outer side is closer to the rotating shaft than the second side.

[0013] Furthermore, the inner lining insert has grooves on both sides of its outer periphery, and a boss is formed between the grooves on both sides, so that the radial thickness of the outer layer of the insert corresponding to the boss is greater than the radial thickness corresponding to the groove.

[0014] Furthermore, both end faces of the inner lining insert are connected to flange structures, which are fixed around the rotating shaft. The flange structures are integrally formed with the inner lining insert, and the outer diameter of the flange structures gradually decreases in the direction away from the inner lining insert.

[0015] Furthermore, the present invention also provides a food processing machine, including a main unit and a cup body, wherein the cup body is provided with a pulverizing blade driven by a brushless motor, and the brushless motor includes a brushless motor rotor.

[0016] The beneficial effects of this invention are: By providing anti-deformation holes in the inner liner insert, an inner insert layer is formed between the anti-deformation holes and the rotating shaft. The radial thickness of the inner insert layer at the bottom end of the anti-deformation hole is greater than the radial thickness of the inner insert layer at the opening end of the anti-deformation hole on the end face of the inner liner insert. The inner insert layer has a first side facing the anti-deformation hole, and the outer insert layer has a second side facing the anti-deformation hole. The second side extends from the bottom end of the anti-deformation hole to the opening end on the end face of the inner liner insert, and the second side is parallel to the axial direction of the rotating shaft. This arrangement, on the one hand, exacerbates the uneven shrinkage of the inner liner insert during cooling, and on the other hand, the inner insert layer is constrained by the position of the rotating shaft. The warping deformation caused by thickness differences is limited, instead increasing the compressive stress on the shaft. This strengthens the bonding force between the inner layer of the insert and the shaft, improving the stability of the connection between the insert and the shaft. Furthermore, the second side of the outer layer effectively prevents stress cracking caused by uneven thickness during injection molding, thus preventing rotor cracking at its source and ensuring stable and reliable torque transmission. When applied to food processing machines, in complex and dynamically changing solid-liquid mixing processing scenarios, it ensures a consistently stable and reliable torque output from the pulverizing blade, with minimal and balanced blade speed fluctuations, achieving efficient material pulverization. Additionally, the side of the outer layer of the insert near the opening of the anti-deformation hole warps significantly away from the shaft, allowing for a convex-concave fit with the outer permanent magnet during injection molding. This results in a tighter bond between the outer permanent magnet and the insert, effectively resisting the heating conditions of the food processing machine. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional schematic diagram of the brushless motor rotor in some embodiments of this application.

[0019] Figure 2 for Figure 1 A side view of the rotor of the brushless motor in the diagram.

[0020] Figure 3 for Figure 1 A schematic diagram of the structure of the brushless motor rotor.

[0021] Figure 4 for Figure 1 A cross-sectional view of the rotor of a brushless motor (without a fan).

[0022] Figure 5 for Figure 4 A magnified view of a portion of point A in the middle.

[0023] Figure 6 This is a cross-sectional schematic diagram of a brushless motor rotor provided in some embodiments of this application.

[0024] Figure 7 for Figure 7 A magnified view of a portion of point B in the middle.

[0025] Figure 8 This is a cross-sectional schematic diagram of a brushless motor rotor provided in some embodiments of this application.

[0026] Figure 9 for Figure 9 A magnified view of a portion of point C.

[0027] Figure 10 This is a cross-sectional schematic diagram of a brushless motor provided in an embodiment of this application.

[0028] Figure 11 for Figure 10 A schematic diagram of the stator assembly of a brushless motor.

[0029] The names of the components shown in the diagram are as follows: 1. Shaft; 2. Inner insert; 201. Anti-deformation hole; 202. Intermediate hole; 203. Slot; 21. Inner layer of insert; 211. First side surface; 22. Outer layer of insert; 221. Second side surface; 23. Partition; 24. Intermediate inner layer; 241. Intermediate inner side surface; 25. Intermediate outer layer; 251. Intermediate outer side surface; 26. Boss; 27. Flange structure; 3. Outer permanent magnet; 4. Fan; 5. Stator assembly; 51. Stator frame; 52. Stator core; 6. Upper end cover; 7. Lower end cover; 8. Upper bearing; 9. Lower bearing. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments. Example

[0032] like Figures 1 to 5As shown, this embodiment provides a brushless motor rotor, which includes an outer permanent magnet 3, an inner insert 2 and a rotating shaft 1 nested from the inside out. The inner insert 2 is fixed to the rotating shaft 1 by injection molding, and the outer permanent magnet 3 is fixed to the inner insert 2 by injection molding.

[0033] Understandably, the inner insert 2 and the outer permanent magnet 3 on the rotating shaft 1 are injection molded sequentially. The inner insert 2 is directly fixed to the rotating shaft 1, and the outer permanent magnet 3 is directly fixed to the inner insert 2, which simplifies the assembly process.

[0034] Along the axial direction of the rotating shaft 1, the length of the outer permanent magnet 3 is the same as the length of the outer circumference of the inner insert 2, so that the inner insert 2 is easy to position in the mold when the outer permanent magnet 3 is injection molded.

[0035] The outer permanent magnet 3 can be a mixture of one or more of ferrite, samarium iron nitrogen, and neodymium iron boron magnetic powders, granulated with PA nylon (or PPS plastic) adhesive substrate, and then injection molded. For motors used in high-speed blending applications, the injection-molded outer permanent magnet 3 has a much lower density than sintered magnets. Under the same size and speed, the high-speed centrifugal force can be significantly reduced, thus, under extreme conditions, the centrifugal stress is less than the tensile strength of the outer permanent magnet 3 itself, eliminating the need for an additional sheath structure. Furthermore, at high speeds, the injection-molded outer permanent magnet 3 has a higher resistivity, which effectively reduces its own eddy currents, thereby reducing the temperature rise caused by eddy currents.

[0036] The aforementioned inner insert 2 is an injection-molded part made of PA nylon (or PPS plastic), which is the same as the bonding substrate of the outer permanent magnet 3, or a composite soft magnet made of PA nylon (or PPS plastic) and iron powder. When the bonding substrate of the inner insert 2 and the outer permanent magnet 3 is the same, the thermal expansion coefficients of the inner insert 2 and the outer permanent magnet 3 are close, which can avoid the risk of thermal shock cracking when directly injection-molded onto traditional magnetic silicon steel sheets. Furthermore, the resistivity of the composite soft magnet is much greater than that of the magnetic silicon steel sheet, which can significantly reduce eddy current losses at high speeds.

[0037] Reference Figure 1 The brushless motor rotor also includes a fan 4, which is mounted on the rotating shaft 1 to dissipate heat.

[0038] Reference Figure 1 and Figure 2The aforementioned outer permanent magnet 3 has a multi-pole ring structure and uses Halbach magnetization, which can enhance the amplitude of the air gap magnetic field of the motor and improve power density. The projections of the outer peripheral surface of the inner liner insert 2 and the inner wall surface of the outer permanent magnet 3 onto a plane perpendicular to the axis of rotation 1 are both polygons, and the polygons formed by both have the same number of sides, which enhances the tightness of their connection. Furthermore, the number of sides of the polygon is the same as the number of magnetic poles of the motor, adjacent magnetic poles have opposite polarities, and the corners of the polygon are aligned with the middle of adjacent magnetic poles. This reduces the amount of material used in the outer permanent magnet 3 while minimizing its impact on motor performance.

[0039] For example, refer to Figure 2 The motor has six electrodes. Correspondingly, the projections of the outer peripheral surface of the inner liner insert 2 and the inner wall surface of the outer permanent magnet 3 onto a plane perpendicular to the axis of rotation 1 are both hexagonal.

[0040] Reference Figure 3 and Figure 4 Both ends of the inner insert 2 are provided with anti-deformation holes 201. The anti-deformation holes 201 extend along the axial direction of the rotating shaft 1. An inner layer 21 of the insert is formed between the anti-deformation holes 201 and the rotating shaft 1. An outer layer 22 of the insert is formed between the anti-deformation holes 201 and the outer permanent magnet 3. The radial thickness of the inner layer 21 at the bottom of the anti-deformation hole 201 is greater than the radial thickness of the inner layer 21 at the opening end of the anti-deformation hole 201 on the end face of the inner insert 2, so as to increase the extrusion force of the end of the inner layer 21 warping toward the rotating shaft 1 during cooling and molding.

[0041] Understandably, as injection molded parts cool after demolding, their dimensions shrink. Taking a cylindrical injection molded part as an example, the cooling process in the radial thickness direction gradually proceeds from the outer periphery inwards, while the cooling process in the axial thickness direction gradually proceeds from both ends towards the center. Therefore, the central part cools and solidifies the slowest, while the circumferentially outer parts and the axially end parts cool and solidify the fastest. The closer the injection molded part is to its center, the slower it cools and solidifies. Thus, while the parts far from the center have already solidified, and the parts near the center are close to solidification, the central part remains relatively unsolidified. It requires a certain amount of time to complete the molding process. During this process, the central part experiences significant shrinkage force, which acts on the already solidified outer parts. This shrinkage force in the center manifests as tensile stress on the remaining parts, causing the entire injection molded part to tend to concave towards the center. This results in warping at both ends of the injection molded part. For cylindrical injection molded parts, after the whole cooling and molding is completed, they usually present a shape that is narrow in the middle and thick at both ends when viewed along the axis, that is, a waist-tight and warped state.

[0042] Therefore, for the inner insert 2 of this application, the cooling and molding principle is the same as that of the injection molded part described above. The only difference is that a rotating shaft 1 is axially inserted in the middle of the inner insert 2, making the inner insert 2 annular. Anti-deformation holes 201 are provided on both end faces of the inner insert 2, so that an inner insert layer 21 is formed between the anti-deformation hole 201 and the rotating shaft 1, and an outer insert layer 22 is formed between the anti-deformation hole 201 and the outer permanent magnet 3. Due to the existence of the anti-deformation hole 201, on the one hand, an inner insert layer 21 and an outer insert layer 22 are formed at both ends of the inner insert 2; on the other hand, the inner wall of the anti-deformation hole 201 is the outer wall of the inner insert layer 21 and the outer insert layer 22, that is, the exposed areas of the inner insert layer 21 and the outer insert layer 22 are both large. Therefore, during the cooling and molding of the inner insert 2, the inner layer 21 and outer layer 22 at both ends of the inner insert 2 cool and solidify at a relatively fast rate, while the cooling and solidification rate of the middle region of the inner insert 2 along the axial direction is relatively slow. In the radial thickness direction of the inner insert 2, since the rotating shaft 1 is inserted, there is no material cooling and solidification in the middle region of the inner insert 2 in the radial thickness direction.

[0043] Therefore, the waist-shrinking warping of the inner insert 2 in this application refers to its annular body structure. During the cooling and molding process, the inner insert 21 and outer insert 22 at both ends of the inner insert 2 cool and solidify quickly, while the middle part of the inner insert 2 in the axial direction cools and solidifies the slowest. The shrinkage force in the middle part is large, and its local shrinkage acts on the inner insert 21 and outer insert 22, which manifests as tensile stress, causing the inner insert 21 to have a tendency to warp towards the direction of the rotation axis 1, and causing the outer insert 22 to have a tendency to warp towards the direction of the outer permanent magnet 3. In this embodiment, an anti-deformation hole 201 is provided, forming an insert inner layer 21 between the anti-deformation hole 201 and the rotating shaft 1. The radial thickness of the insert inner layer 21 at the bottom of the anti-deformation hole 201 is greater than the radial thickness of the insert inner layer 21 at the opening end of the anti-deformation hole 201 on the end face of the inner liner insert 2. The insert inner layer has a first side facing the anti-deformation hole, and the insert outer layer has a second side facing the anti-deformation hole. The second side extends from the bottom of the anti-deformation hole to the opening end on the end face of the inner liner insert, and the second side is parallel to the axial direction of the rotating shaft. That is, the thickness of the insert inner layer 21 is smaller closer to the end face of the inner liner insert 2, and the cooling and solidification speed is faster. On the one hand, it further increases the cooling and solidification speed difference between the inner layer 21 of the insert and the middle part of the inner liner insert 2. On the other hand, it increases the cooling and solidification speed difference between the various parts of the inner layer 21 along the axial direction, thereby aggravating the uneven shrinkage generated during the cooling of the inner liner insert 2, increasing the tensile stress exerted on the inner layer 21 by the middle part of the inner liner insert 2, and increasing the tensile stress of the parts of the inner layer 21 with a slow cooling and solidification speed on the parts with a fast cooling and solidification speed. This increases the degree of warping of the inner layer 21 toward the rotating shaft 1. Meanwhile, the second side of the outer layer of the insert is parallel to the axial direction of the rotating shaft, which prevents the problem of cracking caused by stress due to uneven thickness during the injection molding of the outer layer of the insert.

[0044] Furthermore, those skilled in the art are aware that the inner and outer layers of the insert, facing the anti-deformation hole, present different technical problems and contradictions that need to be overcome. During the research process, the applicant of this invention made creative efforts to discover the technical contradictions of the difference in cooling and solidification rates and stress concentration cracking on the first and second sides, respectively. Thus, the applicant made further creative efforts to develop this solution. The significantly different settings of the second and first sides are indispensable. This allows the inner layer of the insert to effectively combat the problem of the difference in cooling and solidification rates and tensile stress, while the outer layer of the insert can effectively combat the problem of stress concentration cracking while maintaining a uniform thickness.

[0045] In this case, due to the presence of the pivot 1, the inner layer 21 of the insert is restricted by the position of the pivot 1, and the warping deformation tendency of the inner layer 21 of the insert is limited, thereby increasing the compressive stress on the pivot 1, which enhances the expansion and tightening force between the inner layer 21 of the insert and the pivot 1, and improves the bonding stability between the inner insert 2 and the pivot 1.

[0046] Among them, the outer layer 22 of the insert has a larger warping deformation on the side near the opening end of the anti-deformation hole 201 in the direction away from the rotating shaft 1, which can form a concave-convex fit with the outer permanent magnet 3 during injection molding, making the combination of the outer permanent magnet 3 and the inner insert 2 more compact.

[0047] For example, refer to Figure 3 and Figure 4 The aforementioned anti-deformation hole 201 can be selected as a polygonal hole, such as a quadrilateral hole, and the walls of two adjacent holes can be transitioned by a rounded arc, which facilitates injection molding and demolding after injection molding.

[0048] like Figure 3 and Figure 4 As shown, multiple anti-deformation holes 201 are provided on both ends of the inner lining insert 2, and the anti-deformation holes 201 on both sides are arranged opposite each other along the axial direction of the rotating shaft 1.

[0049] Understandably, the number of anti-deformation holes 201 on both sides of the inner insert 2 is the same and they are aligned one by one. That is to say, the anti-deformation holes 201 on both sides are symmetrically distributed in structure, which can ensure the dynamic balance when the whole rotates and is conducive to the correction of dynamic balance.

[0050] Furthermore, multiple anti-deformation holes 201 on each side are equally spaced around the rotating shaft 1. That is, multiple anti-deformation holes 201 on each side are equally spaced in the circumferential direction of the rotating shaft 1, which can further ensure the dynamic balance during overall rotation and facilitate the direct realization of dynamic balance correction through injection molding.

[0051] For example, in one specific implementation, refer to Figure 3 and Figure 4 The number of anti-deformation holes 201 on each side is six, corresponding to the hexagonal shape of the inner lining insert 2.

[0052] like Figure 3 and Figure 4 As shown, both ends of the inner insert 2 are connected to flange structures 27. The flange structures 27 are fixed around the rotating shaft 1. The flange structures 27 and the inner insert 2 are integrally formed. The outer diameter of the flange structures 27 gradually decreases in the direction away from the inner insert 2, which increases the extrusion force on the end of the flange structures 27 as it warps toward the rotating shaft 1 during cooling and forming.

[0053] Understandably, the inner insert 2 has flange structures 27 on both sides. The flange structures 27 increase the bonding length between the inner insert 2 and the rotating shaft 1, thereby increasing the bonding strength between the inner insert 2 and the rotating shaft 1. Moreover, the outer diameter of the flange structure 27 gradually decreases in the direction away from the inner insert 2, meaning that the thickness of the flange structure 27 gradually decreases in the direction away from the inner insert 2. The thinner part of the flange structure 27 cools and solidifies faster. The cooling and solidification speed of the thicker part of the inner insert 2 connected to the flange structure 27 differs from that of the inner insert 2 itself. Thus, during cooling after injection molding, the change in the degree of cooling shrinkage of the flange structure 27 increases the warping degree of the flange structure 27 toward the rotating shaft 1, strengthening the bonding force to the rotating shaft 1, thereby improving the bonding strength between the inner insert 2 and the rotating shaft 1.

[0054] like Figures 3 to 5 As shown, grooves 203 are provided on both sides of the outer periphery of the inner insert 2, and a boss 26 is formed between the grooves 203 on both sides, so that the radial thickness of the outer layer 22 of the insert corresponding to the boss 26 is greater than the radial thickness of the corresponding groove 203.

[0055] Understandably, by forming grooves 203 on both sides of the outer periphery of the inner liner insert 2, a boss 26 is formed between the grooves 203. The presence of the boss 26 can restrict the degree of freedom of the outer permanent magnet 3 in the axial direction of the rotating shaft 1 after the outer permanent magnet 3 is injection molded, thereby improving the bonding between the outer permanent magnet 3 and the inner liner insert 2 and improving the stability of the brushless motor rotor.

[0056] In the radial direction of the rotating shaft 1, the height of the boss 26 is 0.3mm-1.5mm. In addition, in the axial direction of the rotating shaft 1, the length L of the boss 26 is greater than or equal to (L0-0.5)mm, which is beneficial to ensuring the performance of the motor, where L0 is the length of the stator core of the motor in the axial direction of the rotating shaft 1.

[0057] Furthermore, the presence of the boss 26 and the groove 203 makes the radial thickness of the outer layer 22 of the insert corresponding to the boss 26 greater than the radial thickness of the groove 203. This also helps to increase the thickness difference of the outer layer 22 of the insert in the radial direction of the rotating shaft 1, and increase the cooling and solidification rate of the parts of the outer layer 22 of the insert corresponding to the groove 203 at both ends. As a result, the warping deformation of the outer layer 22 of the insert in the axial direction of the rotating shaft 1 from the side close to the end face of the inner insert 2 to the side away from the rotating shaft 1 increases. This can further form a concave-convex fit with the outer permanent magnet 3 during injection molding, making the combination of the two more compact.

[0058] Reference Figure 4 and Figure 5The inner layer 21 of the insert has a first side surface 211 facing the anti-deformation hole 201. The first side surface 211 is inclined from the bottom end of the anti-deformation hole 201 toward the rotating shaft 1. The first side surface 211 is a slope or an arc surface.

[0059] Understandably, the aforementioned first side surface 211 is one of the hole walls of the anti-deformation hole 201. By setting the first side surface 211 to be inclined from the bottom end of the anti-deformation hole 201 toward the rotating shaft 1, that is, the minimum radial distance between the first side surface 211 and the rotating shaft 1 gradually decreases from the bottom end of the anti-deformation hole 201 to the opening end, the radial thickness of the inner layer 21 of the insert gradually decreases from the bottom end of the anti-deformation hole 201 to the opening end. In addition, setting the first side surface 211 at an inclination also facilitates the demolding of the inner insert 2 after injection molding.

[0060] For example, in one specific implementation, the first side surface 211 is selected as an inclined surface.

[0061] Furthermore, referring to Figure 4 and Figure 5 The aforementioned insert outer layer 22 has a second side surface 221 facing the anti-deformation hole 201. The second side surface 221 extends from the bottom end of the anti-deformation hole to the opening end located on the end face of the inner insert 2, and the second side surface 221 is parallel to the axial direction of the rotating shaft 1. That is to say, the arrangement of the second side surface 221 does not cause the radial thickness of the insert outer layer 22 to change in the axial direction of the rotating shaft 1.

[0062] Reference Figure 4 and Figure 5 A partition 23 is provided between the anti-deformation holes 201 on both sides, and the partition 23 separates the anti-deformation holes 201 on both sides.

[0063] Understandably, the aforementioned anti-deformation hole 201 is a blind hole, meaning that the anti-deformation holes 201 on both sides are not connected but are separated by the partition 23. This results in a greater thickness in the middle portion of the inner lining insert 2 along the axial direction of the shaft 1, leading to slower cooling and solidification of the middle portion and thus a greater degree of uneven shrinkage, causing greater warping. This simultaneously improves the bonding strength between the inner lining insert 2, the shaft 1, and the outer permanent magnet 3. Furthermore, the presence of the partition 23 enhances the structural strength of the inner lining insert 2. Moreover, when the inner lining insert 2 is a composite soft magnet formed by mixing a bonding substrate and iron powder, it effectively ensures the magnetic flux cross-sectional area, increasing the utilization of the performance of the outer permanent magnet 3.

[0064] This embodiment also provides a food processing machine, which includes a main unit and a cup assembly. The cup assembly includes a cup body and a cup lid. A pulverizing blade is provided inside the cup body. The pulverizing blade is driven by a brushless motor. The brushless motor includes a stator assembly and a brushless motor rotor. The rotor shaft is directly connected to the blade shaft of the pulverizing blade, or it is connected through a transmission structure. The transmission structure can be an existing power transmission method that is either contact or non-contact, such as an upper and lower connector or an upper and lower transmission disk.

[0065] Specifically, the food processor can be a food processor with a detachable cup body assembly and a main unit, allowing the user to remove the cup body assembly after processing. In this case, the brushless motor can be located either inside the main unit or in the cup holder of the cup body assembly. Alternatively, it can be a food processor with a fixed, integrated design where the main unit and cup body assembly are not detachable. The brushless motor is located below the cup body assembly. After processing, there is no need to remove the cup body; instead, the liquid inside the cup is drained into a receiving cup via a drain valve on the cup body assembly. The food processor then automatically enters a cleaning program, where the control module controls the supply device to introduce water into the cup body to automatically clean the processing chamber inside the cup body, and the wastewater is discharged into a wastewater box.

[0066] Understandably, the brushless motor includes an upper end cover 6, a lower end cover 7, a brushless motor rotor, and a stator assembly 5. One end of the rotor shaft 1 is supported on the upper end cover 6 via an upper bearing 8, and the other end is supported on the lower end cover 7 via a lower bearing 9.

[0067] Understandably, the brushless motor includes an upper cover and a lower cover, and the cup assembly of the food processor includes a cup body, a cup lid, and a cup base. The cup base is located at the bottom of the cup body, and the brushless motor is fixedly mounted on a heating plate at the bottom of the cup body. The heating plate is the upper cover. The heating plate and the lower cover are locked together by locking devices, thereby fixing the brushless motor rotor and stator assembly between the heating plate and the lower cover.

[0068] Understandably, the brushless motor rotor and stator assembly are respectively fixed in the cup holder and main unit of the food processing machine, or both are fixed in the cup holder or both are fixed in the main unit, so that the structure and position of the brushless motor can be adapted according to the different functions and design requirements of the food processing machine.

[0069] Understandably, the brushless motor may also be designed without a lower end cover. The rotor and stator components of the brushless motor can be installed and fixed by setting a limiting structure on the main body structure of the food processing machine, which further simplifies the structure of the brushless motor and further optimizes the heat dissipation effect of the brushless motor. Example

[0070] The structure of the brushless motor rotor provided in this embodiment is basically the same as that of the brushless motor rotor in Embodiment 1. The difference is that the anti-deformation holes 201 on both sides of the inner liner insert 2 are connected by the middle hole 202, that is, there is no partition 23 between the anti-deformation holes 201 on both sides at this time.

[0071] Specifically, refer to Figures 6 to 8 The inner insert 2 has a central hole 202 extending axially along the shaft 1 in the middle, and the central hole 202 connects to the anti-deformation holes 201 on both sides. An intermediate inner layer 24 is formed between the central hole 202 and the shaft 1, and the radial thickness of the intermediate inner layer 24 is greater than the maximum radial thickness of the insert inner layer 21.

[0072] Understandably, in the axial direction of the shaft 1, the radial thickness of the middle inner layer 24 is relatively large, while the thickness of the insert inner layers 21 on both sides of the middle inner layer 24 is relatively small. This can also increase the degree of warping deformation of the insert inner layers 21, thereby enhancing the tight connection between the inner insert 2 and the shaft 1.

[0073] Furthermore, the aforementioned intermediate inner layer 24 has an intermediate inner side surface 241 facing the intermediate hole 202. The intermediate inner side surface 241 and the first side surface 211 form a stepped surface, and the intermediate inner side surface 241 and the first side surface 211 are smoothly transitioned by an arc surface, which facilitates injection molding and also facilitates demolding of the molded inner lining insert 2.

[0074] Furthermore, an intermediate outer layer 25 is formed between the intermediate hole 202 and the outer permanent magnet 3. The intermediate outer layer 25 has an intermediate outer side surface 251 facing the intermediate hole 202, and the insert outer layer 22 has a second side surface 221 facing the deformation-resistant hole 201.

[0075] For example, in one specific implementation, refer to Figure 6 and Figure 7 The second side 221 and the middle outer side 251 are flush. That is to say, at this time, without considering the groove 203 and the boss 26, the radial thickness of the middle inner layer 24 and the radial thickness of the insert outer layer 22 are the same.

[0076] For example, in another specific implementation, refer to Figure 8 and Figure 9 The middle outer side 251 is closer to the pivot 1 than the second side 221. This makes the radial thickness of the middle outer layer 25 greater than the maximum radial thickness of the insert outer layer 22, thus creating a thickness difference between the middle outer layer 25 and the insert outer layer 22, increasing the degree of warping deformation of the insert outer layer 22, thereby enhancing the tight bonding between the inner insert 2 and the outer permanent magnet 3.

[0077] Furthermore, the radial thickness of the intermediate outer layer 25 is greater than the maximum radial thickness of the insert outer layer 22, thus forming a stepped surface between the intermediate outer side 251 and the second side 221. Preferably, the intermediate outer side 251 and the second side 221 are smoothly transitioned by a rounded surface, which not only facilitates injection molding but also facilitates demolding of the molded inner insert 2. Of course, the intermediate outer side 251 and the second side 221 can also be transitioned by a transition slope, with the transition slope and the intermediate outer side 251 and the second side 221 forming an obtuse angle to avoid sharp corners affecting injection molding and subsequent demolding. Example

[0078] This example also provides a motor, including the brushless motor rotor of any of the above embodiments. (Refer to...) Figure 10 and Figure 11 The aforementioned motor also includes an upper end cover 6, a lower end cover 7, and a stator assembly 5. One end of the rotor shaft 1 of the brushless motor is supported on the upper end cover 6 via an upper bearing 8, and the other end is supported on the lower end cover 7 via a lower bearing 9. The stator assembly 5 includes a stator frame 51, a stator core 52, and stator windings. The stator frame 51 is mounted on the stator core 52, and the stator windings are wound around the stator frame 51.

[0079] The length L0 of the stator core 52 along the axial direction of the shaft 1 is 0.75-0.9 times the length of the outer permanent magnet 3 along the axial direction of the shaft 1. In other words, the length of the outer permanent magnet 3 is greater than the length of the stator core 52 along the axial direction of the shaft 1, so as to make full use of the end effect of the stator core 52 to enhance the motor output capability. Under the condition of the same power output, the outer diameter of the brushless motor rotor can be effectively reduced to reduce the centrifugal force during high-speed rotation.

[0080] For example, in one specific implementation, L0 is selected as 12mm, and the length of the outer permanent magnet 3 in the axial direction of the rotating shaft 1 is selected as 15.5mm.

[0081] It is understood that the second side of the outer layer of the insert is parallel to the axis of rotation and includes the functional design required for drafting. The inclined surface or curved surface of the first side is significantly larger than the conventional draft angle.

[0082] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0084] In addition to the preferred embodiments described above, the technical solutions protected by this invention are not limited to the above embodiments. It should be noted that the combination of multiple technical solutions in any one embodiment, as well as the combination of technical solutions in any one embodiment with technical solutions in one or more other embodiments, are within the scope of protection of this invention. Although the invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of this invention are within the scope of protection claimed by this invention.

Claims

1. A brushless motor rotor for a food processing machine, comprising an outer permanent magnet, an inner insert, and a rotating shaft nested sequentially from the outside to the inside, wherein the inner insert is fixedly connected to the rotating shaft by injection molding, and the outer permanent magnet is fixedly connected to the inner insert by injection molding, characterized in that, The inner insert has anti-deformation holes on both end faces, which extend along the axial direction of the rotating shaft. An inner layer of the insert is formed between the anti-deformation holes and the rotating shaft, and an outer layer of the insert is formed between the anti-deformation holes and the outer permanent magnet. The radial thickness of the inner layer of the insert at the bottom end of the anti-deformation hole is greater than the radial thickness of the inner layer of the insert at the opening end of the anti-deformation hole on the end face of the inner insert. The inner layer of the insert has a first side facing the anti-deformation hole, and the outer layer of the insert has a second side facing the anti-deformation hole. The second side extends from the bottom end of the anti-deformation hole to the opening end on the end face of the inner insert, and the second side is parallel to the axial direction of the rotating shaft.

2. The brushless motor rotor according to claim 1, characterized in that, The first side is inclined from the bottom end of the anti-deformation hole toward the rotating shaft, and the first side is an inclined surface or an arc surface.

3. The brushless motor rotor according to claim 1, characterized in that, The inner lining insert has multiple anti-deformation holes on both sides of its end face, and the anti-deformation holes on both sides are arranged opposite each other along the axial direction of the rotating shaft.

4. The brushless motor rotor according to claim 3, characterized in that, Multiple anti-deformation holes on each side are arranged at equal intervals around the rotating shaft.

5. The brushless motor rotor according to claim 3, characterized in that, A partition is provided between the anti-deformation holes on both sides, and the partition separates the anti-deformation holes on both sides.

6. The brushless motor rotor according to claim 1, characterized in that, The inner insert has a central hole extending axially along the rotating shaft, and the central hole connects to the anti-deformation holes on both sides; an intermediate inner layer is formed between the central hole and the rotating shaft, and the radial thickness of the intermediate inner layer is greater than the maximum radial thickness of the insert inner layer.

7. The brushless motor rotor according to claim 1, characterized in that, An intermediate outer layer is formed between the intermediate hole and the outer permanent magnet. The intermediate outer layer has an intermediate outer side facing the intermediate hole. The insert outer layer has a second side facing the anti-deformation hole. The second side is flush with the intermediate outer side, or the intermediate outer side is closer to the rotating shaft than the second side.

8. The brushless motor rotor according to claim 1, characterized in that, The inner lining insert has grooves on both sides of its outer periphery, and a boss is formed between the grooves on both sides, so that the radial thickness of the outer layer of the insert corresponding to the boss is greater than the radial thickness of the groove.

9. The brushless motor rotor according to claim 1, characterized in that, Both ends of the inner lining insert are connected to a flange structure, which is fixed around the rotating shaft. The flange structure is integrally formed with the inner lining insert, and the outer diameter of the flange structure gradually decreases in the direction away from the inner lining insert.

10. A food processing machine, characterized in that, The device includes a main unit and a cup body, wherein the cup body is provided with a shredder driven by a brushless motor, and the brushless motor includes a brushless motor rotor as described in any one of claims 1 to 9.

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