Slotless stator assembly of brushless DC motor, brushless DC motor and toothbrush

Abstract

The present application discloses a slotless stator assembly of a DC brushless motor, a DC brushless motor, and a toothbrush, and relates to the field of motor technology. The slotless stator assembly includes a slotless stator core and a coil winding; the slotless stator core is cylindrical, and a plurality of annular barriers are axially provided on the inner wall of the slotless stator core, and mounting grooves are formed between two adjacent annular barriers, and the mounting grooves are used to fix the coil windings; the winding direction of the coil windings is the radial direction of the slotless stator core. The slotless stator assembly in the present application realizes a slotless design, which effectively reduces the slot torque and the radial and tangential electromagnetic forces of the motor, thereby reducing motor noise, improving motor efficiency, and enhancing user experience.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and in particular to a slotless stator assembly of a brushless DC motor, a brushless DC motor, and a toothbrush. Background Art

[0002] As people's living standards continue to improve, the market for personal care products is growing, and oral care is a top priority. On this basis, electric toothbrushes and oral irrigators are becoming more and more popular among consumers. However, the power motors of electric toothbrushes currently on the market mainly rely on swinging to drive the brush head to achieve the purpose of cleaning. This type of motor vibrates strongly and makes a lot of noise when in use, resulting in a poor user experience. The drive motor currently used in oral irrigators is mainly a brush-rotating motor with an eccentric wheel structure to achieve up and down movement. This type of motor has a complex structure (requires a gear set) and is also noisy.

[0003] Therefore, how to reduce the noise of the motor and improve the user experience is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this application is to provide a slotless stator assembly of a DC brushless motor, a DC brushless motor and a toothbrush, which are used to reduce the noise of the motor and improve the user experience.

[0005] To solve the above technical problems, the present application provides a slotless stator assembly of a brushless DC motor, comprising a slotless stator core and a coil winding;

[0006] The slotless stator core is cylindrical, and a plurality of annular barriers are axially provided on the inner wall of the slotless stator core. An installation groove is formed between two adjacent annular barriers, and the installation groove is used to fix the coil winding; the winding direction of the coil winding is the radial direction of the slotless stator core.

[0007] Preferably, two grooves are axially provided on the outer wall of the slotless stator core, and the grooves are provided with through holes, and the through holes and the grooves are used to fix the lead wires of the coil winding.

[0008] Preferably, the slotless stator core comprises a first semi-cylindrical core and a second semi-cylindrical core; the first semi-cylindrical core and the second semi-cylindrical core are detachably connected;

[0009] Correspondingly, one of the annular blocking members includes two semi-annular blocking members.

[0010] Preferably, a frame is provided on the inner wall of the mounting groove, and the frame is provided between the coil winding and the slotless stator core.

[0011] The present application also provides a brushless DC motor, comprising the slotless stator assembly, a rotor assembly, a housing, and bearings;

[0012] The slotless stator assembly is sleeved on the outer periphery of the rotor assembly, and the slotless stator assembly is arranged inside the casing;

[0013] The rotor assembly includes a shaft and a magnetic steel, wherein the magnetic steel is fixed to the outer circumference of the shaft, and the coil winding in the slotless stator assembly is wound around the outer circumference of the magnetic steel;

[0014] End covers are provided at both ends of the casing, and bearings are provided in the middle of the end covers. The shaft of the rotor assembly passes through the bearings at both ends of the casing and extends out of the casing.

[0015] Preferably, there are multiple magnetic steels, and the polarities of two adjacent magnetic steels are opposite.

[0016] Preferably, it also includes a non-magnetic isolation block; the non-magnetic isolation block is fixed on the outer peripheral surface of the shaft and is located between two adjacent magnetic steels, and the non-magnetic isolation block and the two magnetic steels constitute a Halbach structure.

[0017] Preferably, each of the magnetic steels includes a plurality of tile-shaped magnetic steels; the plurality of tile-shaped magnetic steels are uniformly arranged around the outer circumference of the shaft, the plurality of tile-shaped magnetic steels have the same specifications and polarities, and the gaps between two adjacent tile-shaped magnetic steels are the same.

[0018] Preferably, the bearing is a linear motion ball bearing.

[0019] The present application also provides a toothbrush, comprising the brushless DC motor.

[0020] The present application provides a slotless stator assembly for a brushless DC motor. The slotless stator assembly includes a slotless stator core and coil windings. The slotless stator core is cylindrical, and a plurality of annular barriers are axially provided on the inner wall of the slotless stator core. Mounting slots are formed between adjacent annular barriers, and the mounting slots are used to secure the coil windings. The coil windings are wound in the radial direction of the slotless stator core. The slotless stator assembly in the present application implements a slotless design, effectively reducing the cogging torque and the radial and tangential electromagnetic forces of the motor, thereby reducing motor noise, improving motor efficiency, and enhancing user experience.

[0021] The present application provides a brushless DC motor and a toothbrush, comprising the slotless stator assembly mentioned above, and the effects are as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 A structural diagram of a slotless stator assembly provided in an embodiment of the present application;

[0024] Figure 2 A structural diagram of a slotless stator core provided in an embodiment of the present application;

[0025] Figure 3 A structural diagram of a rotor assembly provided in an embodiment of the present application;

[0026] Figure 4 A structural diagram of a rotor assembly and a slotless stator assembly provided in an embodiment of the present application;

[0027] Figure 5 A cross-sectional view of a brushless DC motor provided in an embodiment of the present application;

[0028] The reference numerals in the drawings are as follows: 11 slotless stator core, 12 coil winding, 21 shaft, 22 magnetic steel, 23 non-magnetic isolation block, 111 annular barrier, 112 mounting slot, 113 groove, 114 through hole, 31 housing, 32 end cover and 33 bearing. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] The core of this application is to provide a slotless stator assembly of a brushless DC motor, a brushless DC motor and a toothbrush.

[0031] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0032] Figure 1 This is a structural diagram of a slotless stator assembly provided in an embodiment of the present application. The slotless stator core 11 and the coil winding 12 constitute the slotless stator assembly. Figure 2The structure diagram of a slotless stator core provided in an embodiment of the present application, the slotless stator core 11 includes a circular barrier 111, a mounting groove 112, a groove 113 and a through hole 114; Figure 2 Since it is half of the slotless stator core 11 , the annular barrier 111 is in a semicircular shape.

[0033] like Figure 1 As shown, the slotless stator assembly includes a slotless stator core 11 and a coil winding 12; the slotless stator core 11 is cylindrical; a plurality of annular barriers 111 are axially provided on the inner wall of the slotless stator core 11, and mounting grooves 112 are formed between two adjacent annular barriers 111, and the mounting grooves 112 are used to fix the coil winding 12; the winding direction of the coil winding 12 is the radial direction of the slotless stator core 11.

[0034] The slotless stator core 11 in the embodiment of the present application is cylindrical and can be divided into two halves and fastened together. That is, the slotless stator core 11 includes a first semi-cylindrical core and a second semi-cylindrical core; the first semi-cylindrical core and the second semi-cylindrical core are detachably connected. Figure 2 It is a structural diagram of a semi-cylindrical iron core; correspondingly, each annular barrier 111 axially provided on the inner wall of the slotless stator core 11 includes two semi-annular barriers. It is understandable that the slotless stator core 11 can also be composed of three petals, four petals, etc. to form a cylindrical column. The embodiment of the present application does not specifically limit the number of annular barriers 111 and coil windings 12, and the corresponding number can be set according to actual conditions. The winding direction of the coil winding 12 is along the radial direction of the slotless stator core 11, which is characterized by high winding efficiency, an axial magnetic field generated, and a radial circumferential current direction.

[0035] The present invention provides a slotless stator assembly for a brushless DC motor, comprising a slotless stator core and coil windings. The slotless stator core is cylindrical, with multiple annular spacers axially disposed on its inner wall. Mounting slots are formed between adjacent annular spacers for securing the coil windings. The coil windings are wound radially of the slotless stator core. The slotless stator assembly in the present invention implements a slotless design, effectively reducing cogging torque and the motor's radial and tangential electromagnetic forces, thereby reducing motor noise, improving motor efficiency, and enhancing user experience.

[0036] Based on the above embodiments, Figure 2As shown, the outer wall of the slotless stator core 11 of the embodiment of the present application is axially provided with two grooves 113, and the grooves 113 are provided with through holes 114. The through holes 114 and the grooves 113 are used to fix the lead wires of the coil windings 12. The number of through holes 114 provided on each groove 113 corresponds to the number of coil windings 12, and the position of the through holes 114 is located at the mounting groove 112. The mounting groove 112 of the coil winding 12 can be provided with a corresponding skeleton or sprayed with insulating material. The skeleton is provided between the coil winding 12 and the slotless stator core 11 to prevent the coil winding 12 from being damaged and causing a short circuit. The stator assembly has no teeth (similar to the hollow cup motor design), which reduces the cogging torque, thereby achieving the purpose of reducing the no-load and load currents and improving the working efficiency of the motor; each coil winding 12 can include an N-slot winding method, and each coil winding 12 has an equal size duty cycle and a phase difference of 180°, and a square wave signal needs to be provided.

[0037] Figure 3 This is a structural diagram of a rotor assembly provided in an embodiment of the present application. The shaft 21, the magnetic steel 22 and the non-magnetic isolation block 23 constitute the rotor assembly. Figure 4 A structural diagram of a rotor assembly and a slotless stator assembly provided in an embodiment of the present application. Figure 5 This is a cross-sectional view of a brushless DC motor provided in an embodiment of the present application. The brushless DC motor includes a slotless stator assembly, a rotor assembly, a housing 31 , a bearing 33 and an end cover 32 .

[0038] like Figure 5 and Figure 4 As shown, the slotless stator assembly is sleeved on the outer circumference of the rotor assembly, and the slotless stator assembly is arranged inside the casing 31; the rotor assembly includes a shaft 21 and a magnet 22, the magnet 22 is fixed on the outer circumference of the shaft 21, and the coil winding 12 in the slotless stator assembly is wound around the outer circumference of the magnet 22; end covers 32 are provided at both ends of the casing 31, and a bearing 33 is provided in the middle of the end cover 32, and the shaft 21 of the rotor assembly passes through the bearings 33 at both ends of the casing 31 and extends out of the casing 31.

[0039] The embodiment of the present application does not specifically limit the bearing 33. The bearing 33 may be a linear motion ball bearing, an oil-containing bearing, or an elastic structure. The present application prefers a linear motion ball bearing. The end covers 32 (a front cover and a rear cover) at both ends of the casing 31 have a bearing chamber in the middle. The outer ring of the bearing 33 is fixed to the bearing chamber of the end cover 32. The inner ring of the bearing 33 is used to fix the shaft 21. The two ends of the shaft 21 are installed in the two inner holes of the bearing 33. Both ends of the shaft 21 extend out of the casing 31. The embodiment of the present application does not specifically limit the shape and number of the magnets 22. They can be ring-shaped or tile-shaped. Figure 3As shown, the magnetic steel 22 in the embodiment of the present application includes a plurality of tile-shaped magnetic steels; the plurality of tile-shaped magnetic steels are uniformly surrounded on the outer circumference of the shaft 21, the plurality of tile-shaped magnetic steels have the same specifications, and the gaps between two adjacent tile-shaped magnetic steels are the same. Figure 5 As shown in the figure, there are two coil windings 12 and two magnets 22. The length of the magnet 22 is greater than the length of the coil winding 12. One end of the magnet 22 is flush with one end of the coil winding 12, while the other end of the magnet 22 (near the end cover 32) protrudes from the end of the coil winding 12. The lengthened distance should be a preset value, which is related to the moving distance set by the DC brushless motor.

[0040] The present invention provides a brushless DC motor comprising the slotless stator assembly of the aforementioned embodiment, a rotor assembly, a housing, and bearings. The motor in the present invention simplifies winding, facilitates assembly of the rotor assembly, eliminates the need for a rotor core, and simplifies the structure. The slotless stator assembly implements a slotless design, effectively avoiding cogging torque and electromagnetic forces between slots, thereby reducing motor noise, improving motor efficiency, and enhancing user experience. Furthermore, the brushless DC motor features bidirectional motion, a long service life, a compact size, light weight, high torque, good stability, and high efficiency.

[0041] Based on the above embodiment, the present invention includes multiple magnets 12, with adjacent magnets 12 having opposite polarities. For example, if there are two magnets 12, one magnet has an S pole on the side closest to the shaft 21 and an N pole on the other side; the other magnet has an N pole on the side closest to the shaft 21 and an S pole on the other side. A non-magnetic isolation block 23 is positioned between two adjacent magnets 22. The non-magnetic isolation block 23 is fixed to the outer circumference of the shaft 21, encircling the outer circumference. The non-magnetic isolation block 23 is axially magnetized. The magnets 22 and the non-magnetic isolation block 23 form a Halbach array, a magnetic structure that is a near-ideal structure in engineering, with the goal of generating the strongest magnetic field using the minimum number of magnets.

[0042] The present application also provides a toothbrush comprising the brushless DC motor described in the above embodiment. Since the components of the brushless DC motor have been described in detail above, they will not be repeated in this embodiment. The present application does not specifically limit the toothbrush to include an electric toothbrush and an oral irrigator.

[0043] A toothbrush provided in an embodiment of the present application includes a brushless DC motor, which includes a slotless stator assembly, a rotor assembly, a housing, and bearings. The motor in this embodiment of the application is simple to wind, facilitating assembly of the rotor assembly, eliminating the need for a rotor core, and resulting in a simple structure. The slotless stator assembly implements a slotless design, effectively reducing cogging torque and radial and tangential electromagnetic forces in the motor, thereby reducing motor noise, improving motor efficiency, and enhancing user experience. Furthermore, the brushless DC motor operates in both directions, has a long service life, is compact, lightweight, has high torque, and exhibits excellent stability and high efficiency.

[0044] The above is a detailed introduction to the slotless stator assembly of the brushless DC motor, the brushless DC motor, and the toothbrush provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to in detail. It should be noted that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0045] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A slotless stator assembly of a brushless DC motor, characterized in that: including a slotless stator core and coil windings; The slotless stator core is cylindrical, and a plurality of annular barriers are axially provided on the inner wall of the slotless stator core. A mounting groove is formed between two adjacent annular barriers, and the mounting groove is used to fix the coil winding; the winding direction of the coil winding is the radial direction of the slotless stator core; The outer wall of the slotless stator core is axially provided with two grooves, each of which is provided with a through hole, and the through hole and the groove are used to fix the lead wires of the coil winding; The slotless stator core comprises a first semi-cylindrical core and a second semi-cylindrical core; the first semi-cylindrical core and the second semi-cylindrical core are detachably connected; Correspondingly, one of the annular blocking members includes two semi-annular blocking members.

2. The slotless stator assembly of the brushless DC motor according to claim 1, characterized in that: A frame is provided on the inner wall of the installation groove, and the frame is provided between the coil winding and the slotless stator core.

3. A brushless DC motor, characterized in that: The slotless stator assembly according to claim 1 or 2 further comprises a rotor assembly, a housing and a bearing; The slotless stator assembly is sleeved on the outer periphery of the rotor assembly, and the slotless stator assembly is arranged inside the casing; The rotor assembly includes a shaft and a magnetic steel, wherein the magnetic steel is fixed to the outer circumference of the shaft, and the coil winding in the slotless stator assembly is wound around the outer circumference of the magnetic steel; End covers are provided at both ends of the casing, and bearings are provided in the middle of the end covers. The shaft of the rotor assembly passes through the bearings at both ends of the casing and extends out of the casing.

4. The brushless DC motor according to claim 3, wherein: There are multiple magnetic steels, and the polarities of two adjacent magnetic steels are opposite.

5. The brushless DC motor according to claim 4, characterized in that: It also includes a non-magnetic isolation block; the non-magnetic isolation block is fixed on the outer peripheral surface of the shaft and is located between two adjacent magnetic steels. The non-magnetic isolation block and the two magnetic steels form a Halbach structure.

6. The brushless DC motor according to claim 4, characterized in that: Each of the magnetic steels includes a plurality of tile-shaped magnetic steels; the plurality of tile-shaped magnetic steels are uniformly arranged around the outer circumference of the shaft, the plurality of tile-shaped magnetic steels have the same specifications and polarities, and the gaps between two adjacent tile-shaped magnetic steels are the same.

7. The brushless DC motor according to claim 3, characterized in that: The bearing is a linear motion ball bearing.

8. A toothbrush, characterized in that: A brushless DC motor comprising the brushless DC motor according to any one of claims 3 to 7.

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