A motor and an electric toothbrush

Abstract

This application discloses a motor and an electric toothbrush. The motor includes a housing, an output shaft, a rotor assembly, and a stator assembly. The housing has a receiving cavity. At least a portion of the output shaft is located in the receiving cavity. The rotor assembly is located in the receiving cavity, surrounding the outer periphery of the output shaft and connected to it. The stator assembly is located in the receiving cavity and includes a stator core and coil windings. The stator core surrounds the outer periphery of the rotor assembly and includes a peripheral portion, stator teeth, and magnetic protrusions. The stator teeth and magnetic protrusions are located between the peripheral portion and the rotor assembly, and are connected to the peripheral portion. The stator teeth and magnetic protrusions are arranged circumferentially along the rotor assembly, and the coil windings are wound on the stator teeth. This reduces areas with large air gaps, thereby enhancing the motor's output performance.

Description

Technical Field

[0001] This application relates to the field of oral care equipment technology, and more particularly to a motor and an electric toothbrush. Background Technology

[0002] An electric motor typically includes a rotor assembly, a stator assembly, and an output shaft. The rotor assembly is connected to the output shaft. The stator assembly includes a stator core and windings wound on the stator core. The stator core is coaxial with the rotor assembly, and there is an air gap between the stator core and the rotor assembly. A rotating electromagnetic field is generated by energizing the windings to drive the rotor assembly to rotate, thereby driving the output shaft to rotate.

[0003] The stator core usually has stator teeth for winding the coils. The air gap between the stator core and the rotor assembly is usually large, except for the part with stator teeth. The magnetic flux density in the larger air gap will be significantly reduced, which will lead to a decrease in the output performance of the motor. Utility Model Content

[0004] This application provides a motor and an electric toothbrush that can reduce areas with large air gaps, thereby enhancing the output performance of the motor.

[0005] In a first aspect, this application provides an electric motor, comprising: The casing has a receiving cavity; The output shaft is at least partially located within the receiving cavity; A rotor assembly, located in the receiving cavity, is disposed around the outer periphery of the output shaft and connected to the output shaft; and, A stator assembly is located in the receiving cavity. The stator assembly includes a stator core and a coil winding. The stator core is arranged around the outer periphery of the rotor assembly. The stator core includes a peripheral portion, stator teeth, and magnetic protrusions. The stator teeth and the magnetic protrusions are both located between the peripheral portion and the rotor assembly, and the stator teeth and the magnetic protrusions are both connected to the peripheral portion. The stator teeth and the magnetic protrusions are arranged circumferentially along the rotor assembly. The coil winding is wound on the stator teeth.

[0006] In some embodiments of this application, the stator teeth and the magnetic protrusions are arranged at intervals, and the stator teeth, the magnetic protrusions, and the peripheral portion together enclose a winding slot to accommodate the coil winding. Most of the coil winding is located within the slot space, allowing the electromagnetic field generated when the coil winding is energized to be concentrated within the winding slot. This results in a more uniform electromagnetic field distribution and a higher magnetic flux density, thereby enabling the stator assembly and rotor assembly to provide a stronger and more stable driving force to the output shaft.

[0007] In some embodiments of this application, the stator teeth include: a winding portion connected to the peripheral portion, the coil winding being wound on the winding portion; and a tooth portion connected to the side of the winding portion facing the rotor assembly, the tooth portion extending circumferentially along the rotor assembly and coaxially disposed with the rotor assembly; wherein the distance between the winding portion and the magnetic guide bump along the circumferential direction of the rotor assembly is greater than the distance between the tooth portion and the magnetic guide bump along the circumferential direction of the rotor assembly. Compared to the winding section, the toothed section is closer to the rotor assembly. The toothed section reduces the air gap between the stator core and the shaft assembly. The smaller distance between the toothed section and the magnetic protrusions results in a smaller gap between them, reducing areas of large air gap between the stator core and the rotor assembly. This reduces areas of low magnetic flux density, leading to a more uniform electromagnetic field distribution. Furthermore, the larger distance between the winding section and the magnetic protrusions allows for a larger gap, increasing the slot space of the winding grooves. This allows for a larger coil winding volume, enabling the winding to hold more wire, thereby increasing the strength of the electromagnetic field provided by the coil winding and further improving the motor's output performance.

[0008] In some embodiments of this application, the magnetically conductive bump includes: a connecting portion connected to the peripheral portion; and a protruding portion connected to the connecting portion on the side facing the rotor assembly; wherein the distance between the connecting portion and the stator teeth along the circumference of the rotor assembly is greater than the distance between the protruding portion and the stator teeth along the circumference of the rotor assembly. Compared to the connecting portion, the protruding portion is closer to the rotor assembly, and the protruding portion is used to reduce the air gap between the stator core and the shaft assembly. The smaller distance between the protruding portion and the stator teeth results in a smaller gap between the protruding portion and the stator teeth, which can reduce the area with a large air gap between the stator core and the rotor assembly, thereby reducing the area with low magnetic flux density and making the electromagnetic field distribution more uniform. Furthermore, the larger distance between the connecting portion and the stator teeth results in a larger gap between the connecting portion and the stator teeth, which can increase the slot space of the winding slot, allowing the coil winding to have a larger volume and more wire to be wound, thereby increasing the strength of the electromagnetic field provided by the coil winding and further improving the output performance of the motor.

[0009] In some embodiments of this application, the stator teeth have a first side facing the rotor assembly, and the magnetic protrusions have a second side facing the rotor assembly. On a plane perpendicular to the axial direction of the output shaft, the outline of the orthographic projection of the first side and the outline of the orthographic projection of the second side lie on the same circle. The radial dimension of the first position on the rotor assembly and the first side along the output shaft can be the same as the radial dimension of the first position and the second side along the output shaft. The first position can be any position on the rotor assembly, such that any position on the rotor assembly is equidistant from the stator teeth and the magnetic protrusions. This ensures that during rotor assembly rotation, when the first position rotates to correspond with either the first or second side, the air gap between the first position and the stator core remains the same. This results in a more uniform air gap distribution between the first position and the stator core during rotation, leading to a more stable driving force on the first position and consequently, a more stable driving force on the rotor assembly.

[0010] In some embodiments of this application, the stator core includes a plurality of stator segments arranged circumferentially along the rotor assembly. Each stator segment includes a peripheral portion, stator teeth, and magnetically conductive bumps. A first gap exists between the peripheral portions of two adjacent stator segments. The first gap can form an electromagnetic field blocking region between two adjacent stator segments, making it difficult for magnetic lines of force generated by the coil windings on one stator body to cross the first gap and enter the region where the other stator body is located, thus preventing mutual interference between the electromagnetic fields generated by the coil windings on the two stator bodies.

[0011] In some embodiments of this application, two adjacent stator sections are separated. The size of the first gap is ensured so that the magnetic lines of force generated by the coil windings on the stator body are less likely to cross the first gap.

[0012] In some embodiments of this application, a locking boss is connected to the inner peripheral wall of the housing, and the locking boss is located in the first gap. The locking boss can play a positioning role when the stator core is installed in the housing, realizing the positioning and installation of the stator core, making the installation of the stator core more convenient, and ensuring the roundness of each stator component; in addition, the locking boss can also play a role in isolating and limiting between the stator components, preventing two adjacent stator components from contacting each other.

[0013] In some embodiments of this application, multiple locking bosses are provided, and the multiple locking bosses are arranged along the axial direction of the output shaft. This can provide more accurate positioning when the stator core is installed in the housing, thereby ensuring the roundness of each stator component.

[0014] In some embodiments of this application, the magnetic permeability of the locking boss is lower than that of the peripheral portion. The lower magnetic permeability of the locking boss results in poorer magnetic conductivity for the magnetic lines of force generated by the coil windings, preventing the magnetic lines of force generated by the coil windings on one stator body from being conducted to the area of ​​another stator body via the locking boss.

[0015] In some embodiments of this application, the peripheral portion, stator teeth, and magnetic bumps of the stator assembly are integrally formed. This improves the connection strength between the stator teeth and magnetic bumps and the peripheral portion, preventing them from detaching from the peripheral portion during installation. Furthermore, the stator teeth and magnetic bumps can be formed from the same material as the peripheral portion, resulting in better overall magnetic conductivity of the stator body and more consistent magnetic conductivity throughout, thereby allowing for a more uniform distribution of the electromagnetic field generated by the coil windings.

[0016] In some embodiments of this application, the stator core further includes a connecting bridge located in the first gap, and the outer peripheries of the two stator components are connected through the connecting bridge. This allows the stator components to be connected and fixed outside the housing via the connecting bridge before being installed inside the housing, making the installation of the stator core more convenient and ensuring the roundness of each stator component.

[0017] In some embodiments of this application, the circumferential dimension of the connecting bridge along the output shaft is smaller than the circumferential dimension of the peripheral portion along the output shaft; and / or the radial dimension of the connecting bridge along the output shaft is smaller than the radial dimension of the peripheral portion along the output shaft. The connecting bridge is shorter and / or narrower than the peripheral portion, resulting in a smaller and narrower magnetic circuit channel. This makes the magnetic circuit channel formed by the connecting bridge more prone to saturation. Once saturated, the magnetic circuit blocks other magnetic lines of force from being transmitted through the connecting bridge. This means that only a very small portion of the magnetic lines of force generated by the coil windings on one stator body can be conducted through the connecting bridge to the region where the other stator body is located, thereby preventing electromagnetic interference between the coil windings on the two stator bodies.

[0018] In some embodiments of this application, the radial dimension of the connecting bridge along the output shaft is less than or equal to 5 mm. This ensures that the magnetic circuit channel formed by the connecting bridge is easily saturated, thereby preventing electromagnetic fields generated by the coil windings on the two stator bodies from interfering with each other.

[0019] In some embodiments of this application, the magnetic bump is connected to the peripheral portion via a deformable connecting structure, allowing the magnetic bump to move relative to the peripheral portion towards and away from the stator teeth. The deformable connecting structure allows the magnetic bump to be moved away from the stator teeth relative to the peripheral portion before winding to form a coil winding, thereby increasing the gap between the magnetic bump and the stator teeth, making winding on the stator teeth more convenient. After winding is completed, the magnetic bump can be moved back towards the stator teeth to reset its position.

[0020] Secondly, this application also provides an electric toothbrush, including a handle and a brush head. The handle includes a housing and a motor as described in any of the above embodiments. The motor is installed in the housing, and one end of the output shaft extends out of the housing and is connected to the brush head to drive the brush head to rotate.

[0021] The beneficial effects of this application are as follows: On the one hand, by setting magnetic guide bumps on the outer periphery of the stator core, which are arranged circumferentially with the stator teeth along the rotor assembly, and the magnetic guide bumps and stator teeth are respectively set at different parts of the stator core, and the magnetic guide bumps protrude towards the rotor assembly, the magnetic guide bumps are closer to the rotor assembly than the outer periphery, making the air gap between the magnetic guide bumps and the rotor assembly smaller. Thus, in addition to the smaller air gap between the part of the stator core with stator teeth and the rotor assembly, the air gap between the part of the stator core with magnetic guide bumps and the rotor assembly is also smaller, which can reduce the area with a large air gap between the stator core and the rotor assembly, thereby reducing the excitation current. On the other hand, it can reduce areas with low magnetic flux density, making the electromagnetic field distribution more uniform and improving the utilization rate of the electromagnetic field, thereby improving the output performance and stability of the motor. Furthermore, since there is no need to increase the input current of the windings, the power consumption of the motor can be reduced, thereby reducing the loss and temperature rise of the coil windings and improving the working efficiency of the coil windings. This can reduce the power consumption and heat generation of the motor and increase the motor's range. In addition, without increasing the core cross-sectional area of ​​the stator and rotor assemblies, without increasing the number of turns of the windings, and without using stronger permanent magnets, the overall size and cost of the motor can be reduced, thereby increasing the power density of the motor. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the motor in one embodiment of this application; Figure 2 This is a cross-sectional view of the motor from a first perspective in one embodiment of this application; Figure 3 This is a cross-sectional view of the motor from a second perspective in one embodiment of this application; Figure 4 This is an exploded view of the motor components in one embodiment of this application; Figure 5 This is a cross-sectional view of the stator core and rotor assembly in one embodiment of this application from a first perspective; Figure 6 This is a schematic diagram of the stator assembly in one embodiment of this application; Figure 7 This is a cross-sectional view of the stator core and rotor assembly from a first perspective in another embodiment of this application; Figure 8 This is a schematic diagram of the stator split structure in another embodiment of this application; Figure 9 This is a cross-sectional view of the motor from a first-view perspective in one embodiment of this application.

[0024] Figure label: 10. Housing; 11. Receiving cavity; 20. Output shaft; 30. Rotor assembly; 31. Rotor core; 32. Magnetic ring; 40. Stator assembly; 41. Stator core; 411. Stator tooth; 411a. Winding section; 411b. Tooth section; 411c. First side surface; 412. Magnetic guide bump; 412a. Connecting section; 412b. Protrusion section; 412c. Second side surface; 413. Peripheral section; 414. Winding slot; 415. Stator body; 416. First gap; 417. Connecting bridge; 418. Connecting structure; 42. Coil winding; 50. Snap-fit ​​boss; 61. Stop block; 62. End cap; 63. Front bearing; 64. Rear bearing. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0026] Stator cores typically have stator teeth for winding the coils. The air gap between the stator core and the rotor assembly, except for the part with stator teeth, is usually large. When the rotor assembly moves to the area with a large air gap, the excitation current generated in the windings will increase, thereby increasing the winding losses, which in turn leads to an increase in winding temperature and a decrease in operating efficiency. Furthermore, the excitation current is mainly used to establish the electromagnetic field and is a reactive current. The increase in air gap will lead to a significant increase in the excitation current, which means an increase in reactive power demand.

[0027] On the other hand, because the magnetic flux density decreases significantly in areas with larger air gaps, the driving force on the rotor assembly decreases, leading to a decline in the motor's output performance (such as torque and thrust). To maintain the motor's output performance, the input current of the windings can be increased, but this will exacerbate winding losses and increase temperature. Alternatively, the cross-sectional area of ​​the stator and rotor cores can be increased to accommodate more magnetic flux, the number of winding turns can be increased to provide a larger magnetomotive force, and stronger (and usually more expensive) permanent magnets can be used to enhance the electromagnetic field. However, these measures will significantly increase the overall size and cost of the motor, and the motor's power density (the ratio of the motor's output power to its weight or volume) will decrease.

[0028] In view of the above-mentioned technical problems, this application provides a motor and an electric toothbrush to solve the above-mentioned technical problems.

[0029] Firstly, this application provides an electric motor, such as Figures 1 to 4 As shown, the motor includes a housing 10, an output shaft 20, a rotor assembly 30, and a stator assembly 40.

[0030] The housing 10 has a receiving cavity 11. The overall shape of the housing 10 can be cylindrical or other shapes, which are used to provide protection for the rotor assembly 30 and stator assembly 40 and other devices inside the housing 10.

[0031] The output shaft 20 is at least partially located in the receiving cavity 11. The output shaft 20 is used to connect to a driven device such as the brush head of an electric toothbrush to provide driving force to the driven device.

[0032] The rotor assembly 30 is located in the receiving cavity 11. The rotor assembly 30 is arranged around the outer periphery of the output shaft 20 and is connected to the output shaft 20. The rotor assembly 30 is used to cooperate with the stator assembly 40 to drive the output shaft 20 to rotate.

[0033] The stator assembly 40 is located in the receiving cavity 11. The stator assembly 40 includes a stator core 41 and a coil winding 42. The stator core 41 is arranged around the outer periphery of the rotor assembly 30. The stator core 41 includes a peripheral portion 413, stator teeth 411, and magnetic protrusions 412. The stator teeth 411 and magnetic protrusions 412 are both located between the peripheral portion 413 and the rotor assembly 30, and the stator teeth 411 and magnetic protrusions 412 are both connected to the peripheral portion 413. The stator teeth 411 and magnetic protrusions 412 are arranged circumferentially along the rotor assembly 30. The coil winding 42 is wound on the stator teeth 411. The coil winding 42 can be formed by winding enameled wire.

[0034] Understandably, when a motor is applied to an electric toothbrush, the brush head is mounted on the output shaft 20. When the coil winding 42 is energized, it generates an electromagnetic field, and the directions of the electromagnetic fields generated by two adjacent coil windings 42 are opposite. The stator core 41 can act as a magnetic conductor, concentrating the electromagnetic field generated by the coil winding 42 within a preset area and forming a closed magnetic flux loop, thereby improving the electromagnetic field strength and utilization rate. The electromagnetic field generated by the coil winding 42 cooperates with the electromagnetic field generated by the rotor assembly 30 to drive the rotating shaft assembly to rotate. When the rotating shaft assembly rotates, it drives the output shaft 20 to rotate, which in turn allows the brush head to reciprocate, enabling the brush head to clean teeth from multiple angles.

[0035] It should also be noted that, on the one hand, by providing magnetically conductive bumps 412 on the outer periphery 413 of the stator core 41, which are arranged circumferentially with the stator teeth 411 along the rotor assembly 30, the magnetically conductive bumps 412 and the stator teeth 411 are respectively provided at different parts of the stator core 41, and the magnetically conductive bumps 412 protrude towards the rotor assembly 30. Compared with the outer periphery 413, the magnetically conductive bumps 412 are closer to the shaft assembly, making the air gap between the magnetically conductive bumps 412 and the shaft assembly smaller. As a result, in addition to the smaller air gap between the part of the stator core 41 with stator teeth 411 and the rotor assembly 30, the air gap between the part of the stator core 41 with magnetically conductive bumps 412 and the rotor assembly 30 is also smaller. This can reduce the area with a large air gap between the stator core 41 and the rotor assembly 30, thereby reducing the excitation current.

[0036] On the other hand, it can reduce areas with low magnetic flux density, making the electromagnetic field distribution more uniform and improving the utilization rate of the electromagnetic field, thereby improving the output performance and stability of the motor. Furthermore, since there is no need to increase the input current of the winding, the power consumption of the motor can be reduced, thereby reducing the loss and temperature rise of the coil winding 42 and improving the working efficiency of the coil winding 42. This can reduce the power consumption and heat generation of the motor and increase the motor's range. In addition, without increasing the core cross-sectional area of ​​the stator assembly 40 and the rotor assembly 30, without increasing the number of turns of the winding, and without using stronger permanent magnets, the overall size and cost of the motor can be reduced, thereby increasing the power density of the motor.

[0037] like Figure 5 and Figure 6 As shown, in some embodiments, stator teeth 411 and magnetic protrusions 412 are arranged at intervals, and the stator teeth 411, magnetic protrusions 412, and peripheral portion 413 together enclose a winding slot 414 to accommodate the coil winding 42. It is understood that most of the coil winding 42 is located within the slot space of the winding slot 414. The electromagnetic field generated when the coil winding 42 is energized can be concentrated within the winding slot 414, resulting in a more uniform electromagnetic field distribution and a higher magnetic flux density. This allows the stator assembly 40 and rotor assembly 30 to provide a stronger and more stable driving force to the output shaft 20.

[0038] Furthermore, the stator tooth 411 includes a winding portion 411a and a tooth portion 411b. The winding portion 411a is connected to the peripheral portion 413, and the coil winding 42 is wound on the winding portion 411a. The winding portion 411a provides a mounting position and support for the coil winding 42. The tooth portion 411b is connected to the side of the winding portion 411a facing the rotor assembly 30, extends circumferentially along the rotor assembly 30, and is coaxially arranged with the rotor assembly 30. The distance between the winding portion 411a and the magnetic protrusion 412 along the circumferential direction of the rotor assembly 30 is greater than the distance between the tooth portion 411b and the magnetic protrusion 412 along the circumferential direction of the rotor assembly 30.

[0039] Understandably, the winding portion 411a, the tooth portion 411b, the magnetic guide bump 412, and the outer portion 413 together form the winding groove 414. Compared to the winding portion 411a, the tooth portion 411b is closer to the rotor assembly 30. The tooth portion 411b is used to reduce the air gap between the stator core 41 and the shaft assembly. Furthermore, the distance between the tooth portion 411b and the magnetic guide bump 412 is smaller, resulting in a smaller gap between the tooth portion 411b and the magnetic guide bump 412. This reduces the air gap between the stator core 41 and the rotor assembly. The larger air gap area of ​​the 30 reduces the area with low magnetic flux density, resulting in a more uniform electromagnetic field distribution. In addition, the larger distance between the winding portion 411a and the magnetic protrusion 412 increases the gap between them, which in turn increases the slot space of the winding slot 414. This allows the coil winding 42 to have a larger volume, enabling it to wind more wire and thus increasing the strength of the electromagnetic field provided by the coil winding 42, thereby further improving the output performance of the motor.

[0040] It should also be noted that an insulating layer can be formed on the winding portion 411a to achieve insulation between the winding portion 411a and the coil winding 42; an insulating support can also be provided between the winding portion 411a and the coil winding 42 to achieve insulation between the winding portion 411a and the coil winding 42; of course, depending on actual needs, other methods can also be used to achieve insulation between the winding portion 411a and the coil winding 42, which are not listed in this application.

[0041] In some embodiments, the magnetic bump 412 includes a connecting portion 412a and a protruding portion 412b; the connecting portion 412a is connected to the peripheral portion 413; the protruding portion 412b is connected to the side of the connecting portion 412a facing the rotor assembly 30. The distance between the connecting portion 412a and the stator teeth 411 along the circumferential direction of the rotor assembly 30 is greater than the distance between the protruding portion 412b and the stator teeth 411 along the circumferential direction of the rotor assembly 30.

[0042] Understandably, compared to the connecting part 412a, the protruding part 412b is closer to the rotor assembly 30. The protruding part 412b is used to reduce the air gap between the stator core 41 and the shaft assembly, and the distance between the protruding part 412b and the stator teeth 411 is smaller, resulting in a smaller gap between the protruding part 412b and the stator teeth 411. This reduces the area with a large air gap between the stator core 41 and the rotor assembly 30, thereby reducing the area with low magnetic flux density and making the electromagnetic field distribution more uniform. In addition, the distance between the connecting part 412a and the stator teeth 411 is larger, resulting in a larger gap between the connecting part 412a and the stator teeth 411. This increases the slot space of the winding slot 414, allowing the coil winding 42 to have a larger volume and more wire to be wound. This, in turn, increases the strength of the electromagnetic field provided by the coil winding 42, further improving the output performance of the motor.

[0043] In some embodiments, the stator tooth 411 has a first side 411c facing the rotor assembly 30, and the magnetic protrusion 412 has a second side 412c facing the rotor assembly 30. On a plane perpendicular to the axial direction of the output shaft 20, the outline of the orthographic projection of the first side 411c and the outline of the orthographic projection of the second side 412c lie on the same circle.

[0044] It is understandable that the first side surface 411c and the second side surface 412c are located on the same circular surface S, which allows the distance between the magnetic guide bump 412 and the rotor assembly 30 to be closer, thereby further reducing the air gap between the part of the stator core 41 (excluding the stator teeth 411) and the rotor assembly 30. In addition, the radial dimension of the first position on the rotor assembly 30 and the first side surface 411c along the output shaft 20 can be the same as the radial dimension of the first position and the second side surface 412c along the output shaft 20. The first position can be any position on the rotor assembly 30. This ensures that any position on the rotor assembly 30 is at the same distance from the stator teeth 411 and the magnetic protrusions 412. As a result, when the rotor assembly 30 rotates to a position corresponding to either the first side 411c or the second side 412c, the air gap between the first position and the stator core 41 remains the same. This makes the air gap distribution between the first position and the stator core 41 more uniform during the rotation of the first position, and thus makes the driving force on the first position more stable, thereby making the driving force on the rotor assembly 30 more stable.

[0045] like Figures 5 to 7As shown, in some embodiments of this application, the stator core 41 includes a plurality of stator segments 415 arranged circumferentially along the rotor assembly 30. Each stator segment 415 includes a peripheral portion 413, stator teeth 411, and magnetic protrusions 412. A first gap 416 is provided between the peripheral portions 413 of two adjacent stator segments 415. The number of stator segments 415 can be two, three, or more. When the number of stator segments 415 is two, the two stator segments 415 can be arranged opposite each other.

[0046] It should be noted that each stator component 415 may be provided with at least one coil winding 42. The electromagnetic fields generated by the coil windings 42 on two adjacent stator components 415 are in opposite directions. The first gap 416 can form an electromagnetic field blocking region between two adjacent stator components 415, making it difficult for the magnetic lines of force generated by the coil windings 42 on one stator body to cross the first gap 416 and enter the region where the other stator body is located. This can prevent the electromagnetic fields generated by the coil windings 42 on the two stator bodies from interfering with each other.

[0047] like Figure 2 and Figure 5 As shown, in some embodiments, two adjacent stator components 415 are separated, so that the two adjacent stator components 415 are spaced apart, thereby making the first gap 416 wider, making it more difficult for the magnetic lines of force generated by the coil winding 42 on the stator body to cross the first gap 416.

[0048] Furthermore, a locking boss 50 is connected to the inner peripheral wall of the housing 10 (e.g., Figure 2 The locking boss 50 is located in the first gap 416. The locking boss 50 can play a positioning role when the stator core 41 is installed in the housing 10, realizing the positioning and installation of the stator core 41, making the installation of the stator core 41 more convenient, and at the same time ensuring the roundness of each stator component 415. In addition, the locking boss 50 can also play a role in isolating and limiting between stator components 415, preventing two adjacent stator components 415 from contacting each other.

[0049] In some embodiments, the permeability of the locking boss 50 is lower than that of the peripheral portion 413. It is understood that permeability is a quantitative description of the magnetic conductivity of a material and is a property of the substance. Generally speaking, the higher the permeability, the stronger the magnetic conductivity. In this embodiment, the lower permeability of the locking boss 50 results in poorer magnetic conductivity of the locking boss 50 for the magnetic lines of force generated by the coil winding 42, preventing the magnetic lines of force generated by the coil winding 42 on one stator body from being conducted through the locking boss 50 to the area where the other stator body is located.

[0050] In some embodiments, multiple locking bosses 50 are provided, and the multiple locking bosses 50 are arranged along the axial direction of the output shaft 20 (e.g., Figure 1 This allows for more accurate positioning of the stator core 41 when it is installed inside the housing 10, ensuring the roundness of each stator component 415.

[0051] like Figure 7 As shown, in some other embodiments, the stator core 41 also includes a connecting bridge 417 located in the first gap 416. The outer periphery 413 of the two stator segments 415 are connected by the connecting bridge 417, so that the stator segments 415 can be connected and fixed outside the housing 10 by the connecting bridge 417 and then installed inside the housing 10. This makes the installation of the stator core 41 more convenient and makes it easier to ensure the roundness of each stator segment 415.

[0052] The connecting bridge 417 may have a smaller circumferential dimension along the output shaft 20 than the peripheral portion 413 along the output shaft 20, making the connecting bridge 417 shorter than the peripheral portion 413; and / or the connecting bridge 417 may have a smaller radial dimension along the output shaft 20 than the peripheral portion 413 along the output shaft 20, making the connecting bridge 417 narrower than the peripheral portion 413.

[0053] Understandably, the connecting bridge 417 is shorter and / or narrower than the outer portion 413, resulting in a smaller and narrower magnetic circuit channel that the connecting bridge 417 can provide. This makes the magnetic circuit channel formed by the connecting bridge 417 more prone to saturation. Once the magnetic circuit is saturated, it will block other magnetic lines of force from being transmitted through the connecting bridge 417. This means that only a very small portion of the magnetic lines of force generated by the coil winding 42 on one stator body can be conducted through the connecting bridge 417 to the area where the other stator body is located, thereby preventing the electromagnetic fields generated by the coil winding 42 on the two stator bodies from interfering with each other.

[0054] In some embodiments, the radial dimension d of the connecting bridge 417 along the output shaft 20 is less than or equal to 5 mm. It is understood that when d is greater than 5 mm, the magnetic circuit channel formed by the connecting bridge 417 is less likely to saturate, easily leading to mutual interference of the electromagnetic fields generated by the coil windings 42 on the two stator bodies, and increasing the volume of the stator core 41, resulting in a larger motor size, which is detrimental to motor miniaturization. Here, d can be 5 mm, 4 mm, 2.5 mm, or other values ​​greater than 0.

[0055] Furthermore, d is less than or equal to 2 mm, allowing the connecting bridge 417 to be narrower, thus making the magnetic circuit channel formed by the connecting bridge 417 more easily saturated, thereby preventing mutual interference of electromagnetic fields generated by the coil windings 42 on the two stator bodies. Here, d can be 2 mm, 1.5 mm, 1 mm, or other values ​​greater than 0.

[0056] In some embodiments, the peripheral portion 413, stator teeth 411, and magnetic protrusions 412 in the stator body 415 can be integrally formed. This can improve the connection strength between the stator teeth 411 and magnetic protrusions 412 and the peripheral portion 413, preventing the stator teeth 411 and magnetic protrusions 412 from detaching from the peripheral portion 413 during installation. Furthermore, the stator teeth 411 and magnetic protrusions 412 and the peripheral portion 413 can be formed using the same material, thereby improving the overall magnetic conductivity of the stator body and making the magnetic conductivity more consistent throughout, which in turn allows for a more uniform distribution of the electromagnetic field generated by the coil windings 42.

[0057] like Figure 8 As shown, in some embodiments, the magnetic bump 412 is connected to the peripheral portion 413 via a deformable connecting structure 418, allowing the magnetic bump 412 to move relative to the peripheral portion 413 towards and away from the stator teeth 411. It is understood that the deformable connecting structure 418 allows the magnetic bump 412 to be moved away from the stator teeth 411 relative to the peripheral portion 413 before winding to form the coil winding 42, thereby increasing the gap between the magnetic bump 412 and the stator teeth 411, making winding on the stator teeth 411 more convenient. After winding is completed, the magnetic bump 412 can be moved back towards the stator teeth 411 to reset its position.

[0058] The connecting structure 418 can be an elastic structure, making it easier to bend and reposition. The elastic structure can be formed of elastic metal, elastic plastic, or other materials.

[0059] like Figure 3 , Figure 4 as well as Figure 9 As shown, in some embodiments, a stop block 61 is connected to the output shaft 20. The stop block 61 and the rotor assembly 30 are arranged at intervals along the axial direction of the output shaft 20. The stop block 61 is used to limit the rotatable angle of the rotor assembly 30, so as to realize the maximum swing limit of the rotor assembly 30 through physical restriction. This allows the rotational swing range of the rotor assembly 30 to be controlled as needed, ensuring that the output shaft 20 of the motor runs according to the set swing. In addition, the rotational swing range of the rotor assembly 30 can be precisely controlled by an algorithm according to actual needs, ensuring that the output shaft 20 of the motor runs strictly according to the set swing. For example, taking a set swing of 25 degrees as an example, the stop block 61 is used for physical limitation so that the maximum swing of the output shaft 20 will not trigger the physical limit. The rotational swing range of the rotor assembly 30 can be designed according to actual needs, and can be 10 degrees, 15 degrees, 20 degrees, 25 degrees or other degrees.

[0060] In some embodiments, the housing 10 is generally elliptical, elongated, or other shaped. The stop block 61 is located within the receiving cavity 11. The stop block 61 is also generally elliptical, elongated, or other shaped. On a plane perpendicular to the axial direction of the output shaft 20, the projected length of the stop block 61 is less than the projected length of the inner circumferential side surface of the housing 10, but greater than the projected width of the inner circumferential side surface of the housing 10. The projected width of the stop block 61 is less than the projected width of the inner circumferential side surface of the housing 10. When the stop block 61 rotates to abut against the long side surface of the inner circumferential side surface of the housing 10, the housing 10 will prevent the stop block 61 from continuing to rotate, thereby achieving maximum swing limitation of the rotor assembly 30 through physical restriction. The maximum swing limitation of the rotor assembly 30 can be designed by adjusting the dimensions of the housing 10 and the stop block 61.

[0061] In other embodiments, the maximum swing limit of the rotor assembly 30 can also be achieved by the stator core 41 cooperating with the stop block 61. In other embodiments, the maximum swing limit of the rotor assembly 30 can also be achieved by other structures cooperating with the stop block 61. For example, the motor can also include an end cover 62, which is disposed on the tail end of the housing 10. The maximum swing limit of the rotor assembly 30 is achieved by the end cover 62 cooperating with the stop block 61.

[0062] like Figure 7 As shown, in some embodiments, on a plane perpendicular to the axial direction of the output shaft 20, the line connecting the first end of the outline of the orthographic projection of the second side surface 412c to the axis of the output shaft 20 is the first line N1, and the line connecting the second end of the outline of the orthographic projection of the second side surface 412c to the axis of the output shaft 20 is the second line N2. The first line N1 and the second line N2 form an angle α.

[0063] The maximum swing amplitude of the rotor assembly 30 is less than or equal to a, so that when the rotor assembly 30 rotates, the magnetic ring 32 of the rotor assembly 30 can rotate within the range of the magnetic protrusion 412, preventing the magnetic ring 32 of the rotor assembly 30 from being subjected to uneven force after rotating to the area where the first gap 416 is located, resulting in difficulty in resetting or a reduction in torque.

[0064] In some embodiments, the rotor assembly 30 may include a rotor core 31 and a plurality of magnetic rings 32. The rotor core 31 is disposed around the outer periphery of the output shaft 20 and is connected to the output shaft 20. The plurality of magnetic rings 32 are arranged at intervals around the outer periphery of the rotor core 31 and are connected to the rotor core 31. The rotor core 31 is used to provide mounting positions for the magnetic rings 32 and has a magnetic guiding function. The magnetic rings 32 are used to generate a magnetic field that cooperates with the electromagnetic field of the coil winding 42 so as to drive the rotor assembly 30 to rotate.

[0065] In some embodiments, the motor further includes a front bearing 63 and a rear bearing 64 sleeved on the output shaft 20. The front bearing 63 is located at the front end of the rotor assembly 30 and connected to the housing 10; the rear bearing 64 is located at the rear end of the rotor assembly 30 and connected to the housing 10 or the end cover 62. The front bearing 63 and the rear bearing 64 can support the output shaft 20, making the rotation of the output shaft 20 smoother and more stable. Combined with the fixing effect of components such as the end cover 62, the entire motor can stably achieve the rotational vibration function during operation.

[0066] Secondly, based on the aforementioned motor, this application also provides an electric toothbrush, including a handle and a brush head. The handle includes a housing and a motor as described in any of the above embodiments. The motor is installed inside the housing, and one end of the output shaft 20 extends out of the housing and is connected to the brush head to drive the brush head to rotate.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electric motor, characterized in that, include: The casing has a receiving cavity; The output shaft is at least partially located within the receiving cavity; A rotor assembly, located in the receiving cavity, is disposed around the outer periphery of the output shaft and connected to the output shaft; and, A stator assembly is located in the receiving cavity. The stator assembly includes a stator core and a coil winding. The stator core is arranged around the outer periphery of the rotor assembly. The stator core includes a peripheral portion, stator teeth, and magnetic protrusions. The stator teeth and the magnetic protrusions are located between the peripheral portion and the rotor assembly, and the stator teeth and the magnetic protrusions are connected to the peripheral portion. The stator teeth and the magnetic protrusions are arranged circumferentially along the rotor assembly. The coil winding is wound on the stator teeth.

2. The motor according to claim 1, characterized in that, The stator teeth and the magnetic protrusions are arranged at intervals, and the stator teeth, the magnetic protrusions, and the outer periphery together form a winding groove to accommodate the coil winding.

3. The motor according to claim 2, characterized in that, The stator teeth include: A winding portion, connected to the peripheral portion, wherein the coil winding is wound on the winding portion; and... The tooth is connected to the side of the winding portion facing the rotor assembly, the tooth extends circumferentially along the rotor assembly and is coaxially arranged with the rotor assembly; Wherein, the distance between the winding portion and the magnetic guide bump along the circumference of the rotor assembly is greater than the distance between the tooth portion and the magnetic guide bump along the circumference of the rotor assembly.

4. The motor according to claim 2, characterized in that, The magnetically conductive bump includes: The connecting part is connected to the peripheral part; and, A protruding portion is connected to the side of the connecting portion facing the rotor assembly; Wherein, the distance between the connecting portion and the stator tooth along the circumference of the rotor assembly is greater than the distance between the protrusion portion and the stator tooth along the circumference of the rotor assembly.

5. The motor according to claim 1, characterized in that, The stator teeth have a first side facing the rotor assembly, and the magnetic protrusions have a second side facing the rotor assembly. On a plane perpendicular to the axial direction of the output shaft, the outline of the orthographic projection of the first side and the outline of the orthographic projection of the second side lie on the same circle.

6. The motor according to claim 1, characterized in that, The stator core includes a plurality of stator segments arranged circumferentially along the rotor assembly. Each stator segment includes a peripheral portion, stator teeth, and magnetic protrusions. A first gap exists between the peripheral portions of two adjacent stator segments.

7. The motor according to claim 6, characterized in that, The two adjacent stator components are set separately.

8. The motor according to claim 7, characterized in that, A locking boss is connected to the inner peripheral wall of the housing, and the locking boss is located in the first gap.

9. The motor according to claim 8, characterized in that, The locking boss is provided in multiple ways, and the multiple locking bosses are arranged along the axial direction of the output shaft.

10. The motor according to claim 8, characterized in that, The magnetic permeability of the locking boss is less than that of the peripheral part.

11. The motor according to claim 6, characterized in that, The outer portion, the stator teeth, and the magnetic bumps of the stator assembly are integrally formed.

12. The motor according to claim 6, characterized in that, The stator core also includes a connecting bridge located in the first gap, and the outer portions of the two stator components are connected by the connecting bridge.

13. The motor according to claim 12, characterized in that, The dimension of the connecting bridge along the output shaft is smaller than the dimension of the peripheral portion along the output shaft; and / or the dimension of the connecting bridge along the output shaft is smaller than the dimension of the peripheral portion along the output shaft.

14. The motor according to claim 12, characterized in that, The radial dimension of the connecting bridge along the output shaft is less than or equal to 5 mm.

15. The motor according to claim 1, characterized in that, The magnetic guide bump is connected to the peripheral portion through a deformable connection structure, so that the magnetic guide bump can move relative to the peripheral portion in directions closer to and further away from the stator teeth.

16. An electric toothbrush, characterized in that, The device includes a brush handle and a brush head. The brush handle includes a housing and a motor as described in any one of claims 1 to 15. The motor is mounted in the housing, and one end of the output shaft extends out of the housing and is connected to the brush head to drive the brush head to rotate.

Images