Electric motor and electric toothbrush

Abstract

The application provides an electric motor and an electric toothbrush. The electric motor comprises a shell with a containing cavity, a first bearing, a rotor assembly and a stator assembly. The shell is provided with an opening communicating with the containing cavity. The first bearing is connected in the containing cavity. The stator assembly is arranged in the containing cavity and is fixed relative to the shell. The rotor assembly comprises a rotating shaft. The rotating shaft comprises a main shaft part and a reduced diameter part. The first end of the main shaft part in the axial direction extends outward from the opening. The outer diameter of the reduced diameter part is smaller than the outer diameter of the main shaft part. The reduced diameter part comprises a first reduced diameter part arranged at the second end of the main shaft part in the axial direction. The first reduced diameter part is connected in the first bearing. The end surface of the main shaft part towards the first reduced diameter part directly or indirectly contacts the end surface of the first bearing. The rotor assembly rotates relative to the stator assembly. In the axial direction of the electric motor, the rotating shaft is not prone to dislocation, thereby improving the axial impact resistance of the electric motor. The copper interstitial parts are saved, and the assembly is facilitated.

Description

Technical Field

[0001] This application relates to the field of electric toothbrush technology, and more particularly to motors and electric toothbrushes. Background Technology

[0002] Electric toothbrushes are popular due to their high cleaning frequency and time-saving, labor-saving features. However, in drop tests or actual use, the motor of existing electric toothbrushes can be damaged or displaced during drops. This includes the motor shaft sinking and the end face of the motor housing sinking. While some technologies add copper bushings to the motor shaft to improve impact resistance, this has limited effectiveness and requires more components, leading to complex assembly and cost-inefficient practices. Even after a drop, the electric toothbrush may still experience motor micro-vibration and jamming due to insufficient axial impact resistance. Summary of the Invention

[0003] In view of this, this application proposes a motor and an electric toothbrush, which aims to simplify the components while improving axial impact resistance.

[0004] The motor according to the first aspect of this application includes: a housing having a receiving cavity and an opening communicating with the receiving cavity; a first bearing connected to the receiving cavity; a stator assembly disposed in the receiving cavity and fixed relative to the housing; and a rotor assembly rotatably disposed in the receiving cavity. The rotor assembly includes a rotating shaft, which includes a main shaft portion and a radially contracted portion. A first axial end of the main shaft portion extends outward from the opening. The outer diameter of the radially contracted portion is smaller than the outer diameter of the main shaft portion. The radially contracted portion includes a first radially contracted portion disposed at a second axial end of the main shaft portion. The first radially contracted portion is connected to the first bearing. The end face of the main shaft portion facing the first radially contracted portion is in direct or indirect contact with the end face of the first bearing. The rotor assembly rotates relative to the stator assembly.

[0005] As can be seen from the above technical solution, the motor proposed in this application forms a stepped shaft by setting the rotating shaft into multiple parts with different outer diameters. After the first radially contracted part and the main shaft part are connected, a stepped surface is formed on the end face of the main shaft part facing the first radially contracted part. The stepped surface and the axial end face of the first radially contracted part away from the main shaft part form a certain drop. The first radially contracted part is connected to the first bearing, and the stepped surface of the main shaft part is supported on the first bearing, or the main shaft part is indirectly supported on the first bearing through other intermediate parts such as buffer parts, thereby confining the entire rotating shaft in the first bearing and enabling the rotating shaft to rotate stably relative to the first bearing. During axial drop, the first bearing can support the main shaft part. Therefore, in the axial direction of the motor, the rotating shaft is not easily misaligned, thereby improving the axial impact resistance of the motor. This application does not require copper spacers on the rotating shaft to improve axial support, saving parts and reducing costs. The rotor assembly of this application can rotate stably when rotating relative to the stator assembly. The first end of the main shaft part is used to connect a cleaning component, thereby driving the cleaning component to rotate stably.

[0006] In some embodiments of this application, the length of the first radially contracted portion along the axial direction of the rotating shaft is less than or equal to the length of the first bearing along the axial direction of the rotating shaft. This avoids the first radially contracted portion extending outward and directly contacting the end of the housing, instead ensuring that the first bearing contacts the end of the housing. This guarantees a sufficiently large contact area between the first bearing and the housing, reducing the axial impact force on the end of the housing during a drop, thereby improving the motor's axial impact resistance. The first radially contracted portion of the rotating shaft does not require more space than the first bearing, and ensures a stable fit between the rotating shaft and the first bearing. Simultaneously, it avoids contact between the first radially contracted portion and the inner surface of the end cover, reducing wear on the rotating shaft relative to the end cover during rotation.

[0007] In some embodiments, the first radial reduction portion is interference-fitted with the first bearing. This enables the first bearing to provide axial support force to the rotating shaft and makes the rotating shaft more stable during rotation.

[0008] In some embodiments of this application, the motor further includes a second bearing and an adhesive groove. The second bearing is disposed in the receiving cavity near the opening. A first end of the main shaft extends outward from the second bearing and the opening for connecting a cleaning component. The portion of the main shaft located at the second bearing has an adhesive groove, the opening of which communicates with the opening. An adhesive portion is disposed within the adhesive groove. By providing the second bearing, further support is provided to the rotating shaft, making its rotation more stable. By providing an adhesive portion on the main shaft, the rotating shaft and the second bearing can be more tightly coupled, improving axial impact resistance.

[0009] In some embodiments, the length of the adhesive groove along the axial direction of the rotating shaft is less than the length of the second bearing along the axial direction of the rotating shaft. This ensures that at least a portion of the inner wall of the second bearing can form a hard contact with the rotating shaft, effectively preventing deformation of the rotating shaft.

[0010] In some further embodiments, the second bearing includes balls, and the length of the adhesive groove along the axial direction of the rotating shaft is less than or equal to the vertical distance between the end face of the second bearing facing the opening and the center of the balls. This further ensures a large area of ​​hard contact between the rotating shaft and the second bearing, and reduces the impact of the adhesive groove on the stiffness and strength of the rotating shaft, provided that the second bearing and the rotating shaft are well bonded and tightly connected.

[0011] In some embodiments of this application, the motor further includes a second bearing and a spring. The second bearing is disposed in the receiving cavity near the opening. The rotor assembly includes a rotor core connected to the main shaft. The spring is disposed between the second bearing and the rotor core. By providing the spring, the rotational effects caused by structural and assembly tolerances of the rotor core can be reduced. The spring also provides axial buffering force, which helps to improve the axial impact resistance of the rotating shaft. In some embodiments, the spring can also be positioned between the rotor core and the second bearing to prevent the rotor core from contacting the top of the second bearing, reducing potential wear and minimizing the risk of abnormal rotation or noise caused by the rotor core contacting the second bearing during rotation.

[0012] In some further embodiments, the spring is sleeved radially outside the main shaft portion; and / or, the spring is clearance-fitted with the main shaft portion. The arrangement of the spring in this application, while maintaining a relatively fixed position, should minimize its impact on the rotation of the rotating shaft.

[0013] In some further embodiments, the motor also includes a shim connected between the spring and the second bearing; and / or, the shim is connected between the spring and the rotor core. By providing a shim, noise can be eliminated; it can also effectively reduce wear between the rotor core and the spring, and between the rotor core and the second bearing.

[0014] In some embodiments of this application, a positioning part is provided inside the housing, which is used to position the stator assembly in the axial direction of its installation within the housing. This positioning part ensures the axial position of the stator assembly is stable after installation, facilitating assembly and providing axial support, thereby improving the stator assembly's axial impact resistance.

[0015] In some embodiments, the housing includes an end cap and a cylindrical body. One end of the cylindrical body is open to form the opening, and the other end of the cylindrical body is open to connect to the end cap. The end cap further includes a support frame, and a groove is provided in the end cap to accommodate the first bearing. The support frame is provided in the groove, and the support frame is clearance-fitted with the end of the rotating shaft. By providing a support frame in the groove, the mechanical properties of the end cap can be improved, providing better support for the first bearing and the first radial reduction section, improving the end cap's resistance to axial impact, and preventing damage to the end cap under axial impact forces. This ensures that the rotating shaft does not contact the end face of the end cap during rotor assembly rotation, reducing wear on the rotating shaft during rotation; simultaneously, it effectively reduces the probability of the rotating shaft sinking into the end face of the end cap under axial impact forces.

[0016] In some further embodiments, the support frame is disposed at the bottom of the groove, and the support frame includes a first bracket and a second bracket, the first bracket and the second bracket having a cross-connected bracket center, and the rotating shaft being correspondingly arranged with the bracket center. This allows the end cap to accommodate and support the first bearing while further strengthening the structural strength of the groove through the first and second brackets, ensuring sufficient rigidity and strength of the end cap and improving its resistance to axial impact. The high structural strength of the bracket center, and the intersection of the first and second brackets, divides the end face space of the end cap into more and smaller spaces, effectively preventing the rotating shaft from embedding into the end face of the end cap under axial impact force.

[0017] In some embodiments of this application, the outer surface of the housing near the opening is provided with a chamfer; and / or, the end face of the housing with the opening has a recessed portion facing inward toward the receiving cavity. By providing the chamfer and the recessed portion, a certain buffer space is formed on the end face of the housing. During a drop, the buffer space can disperse stress, avoiding stress concentration in this area, thereby improving the effect of resisting axial stress impact and preventing the housing from deforming and denting due to axial impact. This optimizes the structure and stress impact resistance of the motor housing.

[0018] In some embodiments of this application, a second bearing is further included, disposed in the receiving cavity near the opening. The reduced diameter portion also includes a second reduced diameter portion. The main shaft portion is provided with the first reduced diameter portion and the second reduced diameter portion at a distance, and at least a portion of the second reduced diameter portion is located in the second bearing and mates with the second bearing. By providing the second reduced diameter portion, a tight fit can be formed between the second bearing and the second reduced diameter portion, and the end face of the main shaft portion facing the second bearing can be in direct or indirect contact with the end face of the second bearing.

[0019] The electric toothbrush proposed in the second aspect of this application includes a cleaning component and a motor as described in any of the foregoing embodiments, wherein the rotating shaft is connected to the cleaning component to drive the cleaning component to rotate for cleaning.

[0020] As can be seen from the above technical solution, the electric toothbrush proposed in this application has improved axial impact resistance of the motor, so the motor is not easily misaligned when subjected to axial impact, and can be correctly and reliably connected with the cleaning component, thereby improving the stability of the motor driving the cleaning component to rotate and achieving efficient and reliable teeth cleaning.

[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of this application. Attached Figure Description

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

[0023] Figure 1 This is a three-dimensional structural schematic diagram of the motor proposed in some embodiments of this application; Figure 2 This is an exploded schematic diagram of an electric motor proposed in some embodiments of this application; Figure 3 This is a longitudinal sectional view of the motor proposed in some embodiments of this application; Figure 4 yes Figure 3 Schematic diagram of the structure of region A in the middle; Figure 5 yes Figure 3 Schematic diagram of the structure of region B in the middle; Figure 6 This is a three-dimensional structural schematic diagram of the rotating shaft proposed in some embodiments of this application; Figure 7 This is a longitudinal sectional view of the rotation shaft proposed in some other embodiments of this application; Figure 8 This is a cross-sectional view of the housing proposed in some embodiments of this application; Figure 9 This is a partial structural diagram of a motor proposed in some embodiments of this application, wherein the rotating shaft and the first bearing are not assembled; Figure 10 This is a three-dimensional structural schematic diagram of the end cap proposed in some embodiments of this application; Figure 11 This is a three-dimensional structural schematic diagram of the end cap proposed in other embodiments of this application; Figure 12 This is a three-dimensional structural schematic diagram of the housing proposed in some embodiments of this application; Figure 13 This is a three-dimensional structural diagram of an electric toothbrush proposed in some embodiments of this application.

[0024] Explanation of reference numerals in the attached figures: 100. Electric motor; 10. Shell; 11. Receiving cavity; 13. Positioning part; 14. End cap; 141. Lead wire inlet; 142. Groove; 143. Limiting groove; 144. Support frame; 1441. First support; 1442. Second support; 1443. Support center; 15. Cylinder body; 151. Opening; 161. Chamfer; 162. Recessed portion; 20. Rotor assembly; 21. Rotating shaft; 211. Main spindle section; 2111. First end; 2112. Second end; 212. Reduction section; 2121. First reduction section; 2122. Second reduction section; 213. Place glue tank; 22. Rotor core; 23. Limiting part; 231. Protrusion; 24. Magnet; 30. Stator assembly; 31. Lead wire; 32. Stator core; 33. Winding frame; 50. Spring components; 81. First bearing; 82. Second bearing; 821. Ball bearing; 1000, Electric toothbrush; 200, Cleaning parts; 300, Brush handle. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the scope of protection of this application.

[0026] Where there is no conflict, the following embodiments and features can be combined with each other.

[0027] like Figure 1 , Figure 2 and Figure 3 As shown, an embodiment of this application proposes a motor 100, which can be used for... Figure 13The electric toothbrush 1000 shown provides the power required for the vibration or oscillation of the cleaning element 200, enabling the cleaning element 200 to achieve efficient cleaning of teeth. The cleaning element 200 here can be a toothbrush head.

[0028] According to an embodiment of this application, a motor 100 is combined with... Figure 2 and Figure 3 As shown, it includes: housing 10, first bearing 81, rotor assembly 20 and stator assembly 30.

[0029] Among them, such as Figure 2 , Figure 3 and Figure 4 As shown, the housing 10 has a receiving cavity 11, and the housing 10 has an opening 151 communicating with the receiving cavity 11. The shape of the receiving cavity 11 can be flexibly designed according to needs. The receiving cavity 11 can accommodate various components, and the inner wall of the receiving cavity 11 can be used to limit other components or connect with other components.

[0030] Furthermore, such as Figure 2 , Figure 3 and Figure 5 As shown, the first bearing 81 is connected in the receiving cavity 11, and the rotor assembly 20 is rotatably disposed in the receiving cavity 11. Figure 3 , Figure 6 and Figure 9 As shown, the rotor assembly 20 includes a rotating shaft 21, which includes a main shaft portion 211 and a radially reduced portion 212. (Refer to...) Figure 2 , Figure 3 , Figure 4 and Figure 12 As shown, the first axial end 2111 of the main shaft 211 extends outward from the opening 151, and the outer diameter of the radial reduction portion 212 is smaller than the outer diameter of the main shaft 211. The first end 2111 of the main shaft 211 extends outside the housing 10 and can serve as a power output end to provide the required power to the cleaning component 200.

[0031] like Figure 3 , Figure 5 and Figure 6 As shown, the radial reduction section 212 includes a first radial reduction section 2121, which is disposed at the second axial end 2112 of the main shaft section 211. The first radial reduction section 2121 is connected in the first bearing 81, and the end face of the main shaft section 211 facing the first radial reduction section 2121 is in direct or indirect contact with the end face of the first bearing 81. The stator assembly 30 is disposed in the receiving cavity 11 and is fixed relative to the housing 10, while the rotor assembly 20 rotates relative to the stator assembly 10. When the motor 100 of this application is working, the stator assembly 30 can form a continuous interaction with the rotor assembly 20, thereby enabling the rotor assembly 20 to rotate continuously and stably.

[0032] As can be seen from the above, the motor 100 proposed in this application forms a stepped shaft by setting multiple parts with different outer diameters on the rotating shaft 21; the first diameter reduction part 2121 and the main shaft part 211 are integrally connected or welded together, and a stepped surface is formed on the end face of the main shaft part 211 facing the first diameter reduction part 2121. The stepped surface and the axial end face of the first diameter reduction part 2121 away from the main shaft part 211 form a certain drop. The first diameter reduction part 2121 is connected to the first bearing 81 and the stepped surface of the main shaft part 211 is supported on the first bearing 81, or the main shaft part 211 is indirectly supported on the first bearing 81 through other intermediate parts such as buffer parts, so that the entire rotating shaft 21 is confined in the first bearing 81, and the rotating shaft 21 can rotate stably relative to the first bearing 81. During the axial drop process, the first bearing 81 can support the main shaft 211. Therefore, in the axial direction of the motor 100, the rotating shaft 21 is not easy to be misaligned, thereby improving the axial impact resistance of the motor 100, making the motor 100 more robust and durable, and extending its service life. The rotor assembly 20 rotates smoothly during the rotation process, reducing the micro-vibration and jamming phenomena that may occur during the rotation of the rotor assembly 20.

[0033] This application eliminates the need for copper spacers on the rotating shaft 21 to improve axial support, saving parts, reducing costs, and simplifying assembly steps. The rotor assembly 20 of this application can rotate stably relative to the stator assembly 30. The first end 2111 of the main shaft portion 211 is used to connect the cleaning component 200, thereby driving the cleaning component 200 to rotate stably.

[0034] Understandably, compared to existing technologies that use copper spacers on the motor shaft to improve axial impact resistance, the impact resistance is limited, requires more components, is complex to assemble, and is not conducive to cost reduction. Even after a drop, the electric toothbrush 1000 may still experience motor micro-vibration and jamming due to insufficient axial impact resistance. The motor 100 in this application does not require copper spacers, simplifying components and assembly steps. Furthermore, by setting the rotating shaft 21 as a main shaft portion 211 with different radii and a first radially reduced portion 2121... This results in the end face of the second end 2112 of the main shaft 211 having an area larger than the area where the main shaft 211 intersects with the first radial reduction portion 2121. This creates a stepped surface in the area where the main shaft 211 is not connected to the first radial reduction portion 2121. This stepped surface facilitates axial contact with the first bearing 81. Meanwhile, the first radial reduction portion 2121 is connected to and fixed by the first bearing 81. Since the first bearing 81 is located in the receiving cavity 11, the rotating shaft 21 of the motor 100 is less likely to shift under axial external force.

[0035] In some embodiments, such as Figure 2As shown, the stator assembly 30 includes a stator core 32, a winding frame 33, and windings (not shown). The winding frame 33 is connected to the upper part of the stator core 32, and the windings are wound on the winding frame 33. When the windings are energized, the stator assembly 30 will generate an alternating electromagnetic field.

[0036] like Figure 2 and Figure 3 As shown, the rotor assembly 20 also includes a rotor core 22 and magnets 24. Multiple magnets 24 are connected to the surface of the rotor core 22, and a rotating shaft 21 is fixedly connected within the rotor core 22. The rotor assembly 20 can be driven by sensing the electromagnetic field generated by the stator assembly 30, thereby causing the rotor assembly 20 to move relative to the stator assembly 30. The specific structure and operating principle of the stator assembly 30 and rotor assembly 20 can be found in the prior art and will not be elaborated here. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0037] In some embodiments of this application, such as Figure 3 and Figure 5 As shown, the length of the first radially contracted portion 2121 along the axial direction of the rotating shaft 21 is less than or equal to the length of the first bearing 81 along the axial direction of the rotating shaft 21. This avoids the first radially contracted portion 2121 extending outward and directly contacting the end of the housing 10. Instead, it allows the first bearing 81 to contact the housing 10, forming a larger contact area. During a drop, this reduces the axial impact force on the end of the housing 10 (e.g., the end cover 14 described later), thereby improving the axial impact resistance of the motor 100. Simultaneously, the first radially contracted portion 2121 of the rotating shaft 21 does not require more space than the length of the shaft hole of the first bearing 81. In other words, the first radially contracted portion 2121 does not require more space than the space needed to arrange the first bearing 81, while allowing for a larger mating area between the rotating shaft 21 and the first bearing 81, resulting in a stable fit. Furthermore, it avoids contact between the first radially contracted portion 2121 and the inner surface of the end cover 14, thereby reducing wear on the rotating shaft 21 relative to the end cover 14 during rotation.

[0038] In some embodiments, the first radial reduction portion 2121 is interference-fitted with the first bearing 81. This ensures a tight connection between the first radial reduction portion 2121 and the first bearing 81, allowing the first bearing 81 to provide axial support for the rotating shaft 21 and making the rotating shaft 21 more stable during rotation. In a specific embodiment, the inner ring of the first bearing 81 is interference-fitted with the first radial reduction portion 2121, while the outer ring of the first bearing 81 is connected to the housing 10. The outer ring can then be fixed relative to the housing 10, and the inner and outer rings are connected by rolling elements, thus enabling the inner ring to rotate stably relative to the outer ring when the rotating shaft 21 rotates. In other embodiments, the first radial reduction portion 2121 and the first bearing 81 can also be non-interference-fitted, with other fillers added between the first bearing 81 and the first radial reduction portion 2121 to ensure a stable connection. For example, adhesive can be used to improve the connection strength between the first radial reduction portion 2121 and the first bearing 81.

[0039] In some embodiments of this application, such as Figure 3 and Figure 4 As shown, the motor 100 also includes a second bearing 82, which is disposed in the receiving cavity 11 near the opening 151, and is combined with Figure 3 and Figure 6 As shown, the first end 2111 of the spindle portion 211 extends outward from the second bearing 82 and the opening 151 for connection. Figure 13 The cleaning component 200 is shown. By providing a second bearing 82, the rotating shaft 21 is further supported. Both the second bearing 82 and the first bearing 81 are connected to the rotating shaft 21, making the rotating shaft 21 more stable when rotating and further improving the axial impact resistance of the rotating shaft 21.

[0040] In some embodiments, such as Figure 3 and Figure 4 As shown, the portion of the main shaft 211 located at the second bearing 82 has a glue-holding groove 213. The groove opening of the glue-holding groove 213 is connected to the opening 151, and the glue-holding groove 213 is used to hold the adhesive portion. By providing the glue-holding groove 213 on the main shaft 211, the glue can flow along the internal space of the glue-holding groove 213 when it is poured in, instead of flowing everywhere. This is beneficial for the adhesive portion formed after the glue cures to be located in a specific area, preventing the glue from flowing down the rotating shaft 21 onto the rotor assembly 20 and stator assembly 30 and causing contamination. The adhesive portion formed after the glue cures can also make the joint between the rotating shaft 21 and the second bearing 82 tighter, improving the axial impact resistance. In a specific embodiment, the glue-holding groove 213 of this application is achieved by partially reducing the diameter of the main shaft 211. That is, the glue-holding groove 213 is approximately an L-shaped groove. The glue-holding groove 213 can be a continuous full circle, or it can be one or more spaced L-shaped grooves.

[0041] In some embodiments, the length of the adhesive groove 213 along the axial direction of the rotating shaft 21 is less than the length of the second bearing 82 along the axial direction of the rotating shaft 21. This ensures that at least a portion of the inner wall of the second bearing 82 can form a hard contact with the rotating shaft 21, effectively preventing deformation of the rotating shaft 21.

[0042] In some further embodiments, such as Figure 4 As shown, the second bearing 82 includes balls 821, and the length of the adhesive groove 213 along the axial direction of the rotating shaft 21 is less than or equal to the vertical distance between the end face of the second bearing 82 facing the opening 151 and the center of the balls 821. This further ensures a large area of ​​hard contact between the rotating shaft 21 and the second bearing 82, and reduces the impact of the adhesive groove 213 on the rigidity and strength of the rotating shaft 21, provided that the second bearing 82 and the rotating shaft 21 are well bonded and tightly connected. Exemplarily, the opening of the adhesive groove 213 in this application is connected to the opening 151, facilitating the injection of adhesive into the groove 213 from the opening 151 after the rotating shaft 21 is installed. After the adhesive cures, a tight connection between the rotating shaft 21 and the second bearing 82 can be achieved.

[0043] In some embodiments, the length of the glue-filling groove 213 along the axial direction perpendicular to the rotating shaft 21 is less than or equal to 0.2 mm. That is, the glue-filling groove 213 is achieved by reducing the radial dimension of part of the rotating shaft 21. Controlling the reduced diameter to less than or equal to 0.2 mm can effectively prevent excessive injection of soft glue, which would weaken the supporting force of the second bearing 82. It can also ensure the mechanical strength of the rotating shaft 21 and ensure that it has the required anti-torsion effect.

[0044] In some embodiments of this application, combined with Figure 3 and Figure 5As shown, the motor 100 also includes a second bearing 82 and a spring member 50. The second bearing 82 is located in the receiving cavity 11 near the opening 151. The function of the second bearing 82 is as described above and will not be repeated here. Further, the rotor assembly 20 includes a rotor core 22, which is connected to the main shaft portion 211. The spring member 50 is located between the second bearing 82 and the rotor core 22. In these embodiments, by providing the spring member 50, the impact of structural tolerances generated during the machining of the rotor core 22 on the operation of the entire motor 100 can be reduced, as can the rotational impact caused by assembly tolerances generated during the assembly of the rotor assembly 20. In addition, the spring member 50 can also provide axial buffering force, which helps to improve the axial impact resistance of the rotating shaft 21. At the same time, the spring member 50 can also limit the rotor core 22 and the second bearing 82, preventing the rotor core 22 from abutting against the top of the second bearing 82, reducing possible wear, and reducing the risk of abnormal rotation or abnormal noise caused by the rotor core 22 touching the second bearing 82 during rotation. In a specific embodiment, the spring element 50 is a rectangular spring or a circular spring, or the spring element 50 is a torsion spring.

[0045] In some further embodiments, such as Figure 3 and Figure 4 As shown, the spring 50 is fitted radially outward of the main shaft 211. This prevents it from loosening or misaligning relative to the main shaft 211, and helps the spring 50 to remain between the rotor core 22 and the second bearing 82.

[0046] In other embodiments, the spring member 50 is clearance-fitted with the spindle portion 211, that is, the inner diameter of the spring member 50 is larger than the outer diameter of the spindle portion 211, thereby allowing the two to be clearance-fitted.

[0047] In some other embodiments, the spring member 50 is sleeved on the radially outer side of the main shaft portion 211, and the spring member 50 and the main shaft portion 211 are in clearance fit. In this application, the spring member 50 is positioned in a relatively fixed manner, so as not to affect the rotation of the rotating shaft 21 as much as possible.

[0048] In some specific embodiments, one end of the spring element 50 is connected to the second bearing 82, and the other end of the spring element 50, under normal conditions without axial impact force, is in clearance fit or contact with the end face of the rotor core 22. This not only effectively buffers the spring element 50 when there is axial force, but also minimizes interference from the spring element 50 during operation of the rotor assembly 20, eliminating the need to rotate the spring element 50. The spring element 50 in these embodiments is suitable for rectangular or circular springs.

[0049] Of course, the arrangement of the spring element 50 is not limited to the above-described configuration. In other embodiments, one end of the spring element 50 is connected to the second bearing 82, and the other end of the spring element 50 is connected to the rotor core 22. Thus, during the rotation of the rotor assembly 20, the spring element 50 and the rotor assembly 20 twist together at a certain angle, which facilitates the rapid reset of the rotor assembly 20 after twisting to the maximum angle. The spring element 50 in these embodiments is suitable for torsion springs.

[0050] In some further embodiments, the motor 100 also includes shims (not shown), which are connected between the spring member 50 and the second bearing 82; or, the shims are connected between the spring member 50 and the rotor core 22; or, one shim is connected between the spring member 50 and the second bearing 82 and another shim is connected between the spring member 50 and the rotor core 22. By providing shims, noise can be eliminated; wear between the rotor core 22 and the spring member 50, and between the rotor core 22 and the second bearing 82 can be effectively reduced; the contact area between the spring member 50 and the rotor core 22 can be increased, reducing the impact force of the spring member 50 on the rotor core 22; or the contact area between the spring member 50 and the second bearing 82 can be increased, reducing the impact force of the spring member 50 on the second bearing 82. In a specific embodiment, the shims can be connected to the spring member 50, thereby making the position of the shims relatively fixed in the motor 100.

[0051] In other words, in this application, the spring 50 can be directly connected to the second bearing 82 and the rotor core 22; or it can be located between the two without direct connection, such as being sleeved on the main shaft 211; or it can be indirectly connected through a shim, which is not limited here.

[0052] In some embodiments of this application, such as Figure 3 and Figure 8 As shown, a positioning part 13 is provided inside the housing 10. The positioning part 13 is used to position the stator assembly 30 in the axial position within the housing 10. This positioning part 13 ensures the axial position of the stator assembly 30 is stable after installation, facilitating its assembly. Simultaneously, the positioning part 13 provides axial support for the stator assembly 30, improving its axial impact resistance. When the motor 100 is operating, the stator assembly 30 and the rotor assembly 20 continuously generate electromagnetic interaction, promoting stable rotor rotation. In other words, when the stator assembly 30 is assembled into the receiving cavity 11, it is positioned axially within the housing 10 upon contact with the positioning part 13, thus fixing the stator assembly 30's position relative to the entire housing 10 and preventing axial wobbling. In a specific embodiment, the end of the winding frame 33 furthest from the opening 151 abuts against the bottom of the housing 10, for example, against the end cap 14 described later, thereby fixing the axial position of the entire stator assembly 30 within the receiving cavity 11 and preventing wobbling.

[0053] In some further embodiments, such as Figure 2 As shown, the housing 10 includes an end cap 14 and a cylindrical body 15. An opening 151 is formed at one end of the cylindrical body 15, and the opening at the other end of the cylindrical body 15 is connected to the end cap 14. Therefore, when the stator assembly 30 and rotor assembly 20 are assembled in the receiving cavity 11, the motor 100 can be formed into a single unit by connecting the end cap 14 to the opening of the cylindrical body 15. This facilitates the assembly and disassembly of the various components in the receiving cavity 11 and also facilitates sealing the receiving cavity 11. Figure 2 , Figure 3 , Figure 10 and Figure 11 As shown, the end cover 14 has a lead-in port 141, from which the lead wires 31 of the stator assembly 30 extend outward. After extending from the lead-in port 141, the lead wires 31 of the stator assembly 30 can be connected to a power source, allowing the power source to supply power to the stator assembly 30 and provide the necessary power for the rotation of the rotor assembly 20. The lead-in port 141 also provides guidance and protection for the lead wires 31, preventing accidental contact with the lead wires 31 during the rotation of the rotor assembly 20, which could lead to entanglement, damage, or malfunction.

[0054] In some embodiments, the end cap 14 is detachably connected to the cylinder 15, thereby facilitating the opening or closing of the opening on one side of the cylinder 15 having the end cap 14. The detachable connection can be at least one of plug-in, snap-fit, or fastener connection, and is not limited herein.

[0055] In some further embodiments, such as Figure 3 , Figure 5 and Figure 9 As shown, the rotor assembly 20 also includes a limiting part 23, which is connected to the main shaft part 211. The end cover 14 has a groove 142 for connecting the first bearing 81, thereby stably connecting the first bearing 81 within the end cover 14. Further, as... Figure 10 As shown, the end cap 14 is provided with a limiting groove 143. The limiting groove 143 communicates with the groove 142 and the receiving cavity 11 on both sides along the axial direction of the rotating shaft 21, respectively, so that the first radially reduced part 2121 of the rotating shaft 21 can extend into the first bearing 81, while the limiting part 23 can fit into the limiting groove 143, and the main shaft part 211 can extend into the receiving cavity 11. Furthermore, Figure 10 The limiting groove 143 in the middle and Figure 9The limiting part 23 cooperates with the limiting groove 143, and the limiting part 23 can rotate within a certain angle relative to the limiting groove 143. Therefore, the cooperation between the limiting part 23 and the limiting groove 143 in this application limits the maximum angle of rotation of the rotor assembly 20, which is beneficial for the rotor assembly 20 to rotate within a certain angle range relative to the stator assembly 30, thereby enabling the cleaning component 200 connected to the rotating shaft 21 to oscillate. In a specific embodiment, the limiting groove 143 includes two arc-shaped groove walls and two linear groove walls, with each arc-shaped groove wall connected to a linear groove wall at both ends; for example... Figure 9 As shown, the limiting part 23 includes a protrusion 231 that cooperates with the arc-shaped groove wall. The rotation of the rotor assembly 20 can drive the protrusion 231 to swing along the arc-shaped groove wall, thereby realizing the rotation of the rotor assembly 20 relative to the stator assembly 30 within a certain angle range.

[0056] In some embodiments, such as Figure 2 As shown, the housing 10 includes an end cap 14 and a cylindrical body 15. One end of the cylindrical body 15 is open, forming an opening 151, and the other end of the cylindrical body 15 is open and connected to the end cap 14; as Figure 11 As shown, the end cover 14 also includes a support frame 144. A groove 142 is provided in the end cover 14 to house the first bearing 81. The support frame 144 is provided in the groove 142 and has a clearance fit with the end of the rotating shaft 21. By providing the support frame 144 in the groove 142, the mechanical properties of the end cover 14 can be improved, such as increasing its rigidity and strength, providing better support for the first bearing 81 and the first radial reduction portion 2121, thereby improving the end cover 14's resistance to axial impact and preventing damage to the end cover 14 under axial impact forces. This ensures that the rotating shaft 21 does not contact the end face of the end cover 14 during the rotation of the rotor assembly 20, reducing wear on the rotating shaft 21 during rotation; simultaneously, it effectively reduces the probability of the rotating shaft 21 sinking into the end face of the end cover 14 under axial impact forces.

[0057] In some further embodiments, such as Figure 11As shown, the support frame 144 is located at the bottom of the groove 142. The support frame 144 includes a first bracket 1441 and a second bracket 1442. The first bracket 1441 and the second bracket 1442 have a cross-connected bracket center 1443, and the rotating shaft 21 is correspondingly arranged with the bracket center 1443. This allows the end cover 14 to not only accommodate the first bearing 81 in the groove 142 and provide support for the first bearing 81, but also further strengthen the structural strength of the groove 142 through the first bracket 1441 and the second bracket 1442, ensuring that the end cover 14 has sufficient rigidity and strength, and improving the axial impact resistance of the end cover 14. The structural strength of the bracket center 1443 is high, and the intersection of the first bracket 1441 and the second bracket 1442 divides the end face space of the end cover 14 into more and smaller spaces, effectively preventing the rotating shaft 21 from embedding into the end face of the end cover 14 under the action of axial impact force. Of course, in other embodiments, the structure of the support frame 144 can also be other structures, such as including multiple radial support bars, with more than three support bars; or it can include concentric annular protrusions, and the inner diameter of the central annulus is smaller than the outer diameter of the first diameter reduction portion 2121, so that the first diameter reduction portion 2121 will not sink into the central annulus, that is, it will not sink into the end cap 14.

[0058] In some embodiments of this application, combined with Figure 2 and Figure 12 As shown, the outer surface of the housing 10 near the opening 151 has a chamfer 161; and / or, the end face of the housing 10 with the opening 151 has a recess 162 that faces inward toward the receiving cavity 11. By providing the chamfer 161 and the recess 162, a certain buffer space is formed on the end face of the housing 10. During the drop, the buffer space can disperse stress and avoid stress concentration in this area, thereby improving the effect of resisting axial stress impact and preventing the housing 10 from deforming and denting due to axial impact. This optimizes the structure and stress impact resistance of the motor 100 housing 10, and also effectively prevents the housing 10 from denting due to axial impact.

[0059] In some embodiments of this application, reference is made to Figure 4 The motor 100 also includes a second bearing 82, which is disposed in the receiving cavity 11 near the opening 151, as shown in the reference. Figure 7 The reduced diameter portion 212 further includes a second reduced diameter portion 2122. The main shaft portion 211 is provided with a first reduced diameter portion 2121 and a second reduced diameter portion 2122 spaced apart, and at least a portion of the second reduced diameter portion 2122 is located in and cooperates with the second bearing 82. By providing the second reduced diameter portion 2122, the second bearing 82 and the second reduced diameter portion 2122 can form a tight fit, so that the rotating shaft 21 can rotate stably under the constraint of the first bearing 81 and the second bearing 82.

[0060] In some embodiments, the end face of the main shaft 211 facing the second bearing 82 may be in direct or indirect contact with the end face of the second bearing 82, so that the main shaft 211, the first bearing 81 and the second bearing 82 are fixed in the axial direction along the rotating shaft 21, and a large contact surface is formed with the two bearings. When subjected to axial impact force during the drop, the rotating shaft 21 is not easy to shake and change position.

[0061] In other embodiments, the second diameter reduction portion 2122 of this application can also be the aforementioned adhesive groove 213, that is, the circumferential adhesive of the second diameter reduction portion 2122 is applied to form a stable fit with the second bearing 82, thereby improving the connection stability between the rotating shaft 21 and the second bearing 82. In a specific embodiment, the variable diameter stepped surface formed between the main shaft portion 211 and the second diameter reduction portion 2122 contacts the second bearing 82. The space enclosed by the main shaft portion 211, the second bearing 82, and the second diameter reduction portion 2122 is used to apply adhesive to prevent the adhesive from overflowing. In other specific embodiments, the variable diameter stepped surface formed between the main shaft portion 211 and the second diameter reduction portion 2122 is also located in the second bearing 82. The variable diameter stepped surface can prevent the adhesive applied to the outer periphery of the second diameter reduction portion 2122 from flowing axially downward, thereby not only forming a hard contact between the main shaft portion 211 and the second bearing 82, but also making the adhesive connection between the second diameter reduction portion 2122 and the second bearing 82 more stable.

[0062] In other embodiments, a portion of the circumferential surface of the second radially constricted portion 2122 of this application is further radially constricted to form an adhesive groove 213, and an adhesive is coated in the adhesive groove 213 to connect the second radially constricted portion 2122 with the second bearing 82. The depth of the adhesive groove 213 is less than the length of the second radially constricted portion 2122 along the axial direction of the rotation axis 21, thereby achieving a tight connection between the second radially constricted portion 2122 and the second bearing 82, while also enabling a hard contact between the second bearing 82 and the second radially constricted portion 2122.

[0063] The electric toothbrush 1000 of this application is described below.

[0064] Combination Figure 3 and Figure 13 As shown, the electric toothbrush 1000 proposed in this application includes a cleaning component 200 and a motor 100 of any of the aforementioned embodiments. A rotating shaft 21 is connected to the cleaning component 200 to drive the cleaning component 200 to rotate for cleaning.

[0065] As can be seen from the above, the electric toothbrush 1000 proposed in this application has improved axial impact resistance of the motor 100, so the motor 100 is not easily misaligned when subjected to axial impact, and can be correctly and reliably connected with the cleaning component 200, thereby improving the stability of the motor 100 driving the cleaning component 200 to rotate and achieving efficient and reliable teeth cleaning.

[0066] In some embodiments, the electric toothbrush 1000 also includes a handle 300, which contains components such as a battery, a main control circuit board, and a motor 100 (not shown). The handle 300 can be held by hand, and all internal components can be made into a module, keeping the relative positions of the internal parts unchanged and sealing the internal components for user convenience.

[0067] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0068] In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically defined.

[0069] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An electric motor, characterized in that, include: A housing having a receiving cavity and an opening communicating with the receiving cavity; A first bearing is connected in the receiving cavity; A stator assembly disposed in the receiving cavity and fixed relative to the housing; A rotor assembly is rotatably disposed in the receiving cavity. The rotor assembly includes a rotating shaft, which includes a main shaft portion and a radially contracted portion. A first axial end of the main shaft portion extends outward from the opening. The outer diameter of the radially contracted portion is smaller than the outer diameter of the main shaft portion. The radially contracted portion includes a first radially contracted portion, which is disposed at a second axial end of the main shaft portion. The first radially contracted portion is connected to a first bearing. The end face of the main shaft portion facing the first radially contracted portion is in direct or indirect contact with the end face of the first bearing. The rotor assembly rotates relative to the stator assembly.

2. The motor as described in claim 1, characterized in that, The length of the first radially contracted portion along the axial direction of the rotation axis is less than or equal to the length of the first bearing along the axial direction of the rotation axis.

3. The motor as described in claim 1, characterized in that, The first diameter reduction portion is interference-fitted with the first bearing.

4. The motor as described in claim 1, characterized in that, It also includes a second bearing and a glue-holding groove. The second bearing is located in the receiving cavity near the opening. The first end of the main shaft extends outward from the second bearing and the opening for connecting the cleaning component. The portion of the main shaft located at the second bearing has a glue-holding groove, the groove opening of which is connected to the opening, and the glue-holding groove is used to set an adhesive part.

5. The motor as described in claim 4, characterized in that, The length of the adhesive groove along the axial direction of the rotating shaft is less than the length of the second bearing along the axial direction of the rotating shaft.

6. The motor as described in claim 5, characterized in that, The second bearing includes balls, and the length of the rubber groove along the axial direction of the rotating shaft is less than or equal to the vertical distance between the end face of the second bearing facing the opening and the center of the balls.

7. The motor as described in claim 1, characterized in that, It also includes a second bearing and a spring member, the second bearing being disposed in the receiving cavity near the opening, the rotor assembly including a rotor core connected to the main shaft, and the spring member being disposed between the second bearing and the rotor core.

8. The motor as described in claim 7, characterized in that, The spring element is sleeved on the radially outer side of the main shaft portion; and / or, The spring component is clearance-fitted with the main shaft.

9. The motor as described in claim 7, characterized in that, It also includes a gasket connected between the spring and the second bearing; and / or, the gasket connected between the spring and the rotor core.

10. The motor as described in claim 1, characterized in that, The housing is provided with a positioning part, which is used to position the stator assembly in the axial position when it is installed in the housing.

11. The motor as described in claim 1, characterized in that, The housing includes an end cap and a cylindrical body. One end of the cylindrical body is open to form the opening, and the other end of the cylindrical body is open to connect to the end cap. The end cap also includes a support frame. The end cap has a groove for housing the first bearing. The groove has a support frame, and the support frame is clearance-fitted with the end of the rotating shaft.

12. The motor as described in claim 11, characterized in that, The support frame is installed at the bottom of the groove. The support frame includes a first bracket and a second bracket. The first bracket and the second bracket have cross-connected bracket centers. The rotating shaft is arranged corresponding to the bracket centers.

13. The motor as described in claim 1, characterized in that, The exterior of the housing near the opening is chamfered; and / or, The end face of the housing having the opening has a recess that is recessed toward the receiving cavity.

14. The motor as described in claim 1, characterized in that, It also includes a second bearing, which is disposed in the receiving cavity near the opening. The radial reduction portion also includes a second radial reduction portion. The first radial reduction portion and the second radial reduction portion are spaced apart on the main shaft portion, and at least a portion of the second radial reduction portion is located in the second bearing and cooperates with the second bearing.

15. An electric toothbrush, characterized in that, include: The cleaning component and the motor as described in any one of claims 1 to 14, wherein the rotating shaft is connected to the cleaning component to drive the cleaning component to rotate for cleaning.

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