CN217510637U

CN217510637U - Toothbrush power device and mini electric toothbrush with same

Info

Publication number: CN217510637U
Application number: CN202221360001.3U
Authority: CN
Inventors: 曾梦伟; 孟凡迪
Original assignee: Shenzhen Sushi Technology Co Ltd
Current assignee: Shenzhen Sushi Technology Co Ltd
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-09-30
Anticipated expiration: 2032-05-31

Abstract

The application is applicable to electric toothbrush technical field, provides a toothbrush power device and has its mini electric toothbrush, and wherein toothbrush power device includes: the electromagnetic driving device comprises a main body, an electromagnetic driving part, a transmission part and a supporting part; the electromagnetic driving part is fixedly arranged on the main body and comprises an electromagnet, the transmission part comprises a transmission shaft, the transmission shaft is movably arranged in the main body in a penetrating mode, a magnet is arranged at the first end of the transmission shaft, two magnetic poles of the magnet are arranged along the motion direction of the transmission shaft, the magnetic pole, far away from the transmission shaft, of the magnet is arranged opposite to the electromagnetic control end, and the second end of the transmission shaft is used for being connected with the brush head assembly; supporting part fixed mounting is in the main part, and the inside of supporting part is provided with the through-hole, is provided with the convex part on the through-hole inner wall, and the second end of transmission shaft wears to establish in the through-hole to with convex part interference fit, the toothbrush power device that this application provided occupies that the volume is less, the time of endurance is long, and brush first subassembly reaches higher vibration frequency.

Description

Toothbrush power device and mini electric toothbrush with same

Technical Field

The application belongs to the technical field of electric toothbrushes, and particularly relates to a toothbrush power device and a mini electric toothbrush with the same.

Background

The electric toothbrush is a tooth cleaning tool which can instantly decompose toothpaste into fine foam and deeply clean slits between teeth by virtue of quick rotation or vibration of the motor core, and the electric toothbrush is widely used in daily life of people, has smaller volume compared with a common electric toothbrush due to excellent cleaning capability and comfortable cleaning experience, is convenient for people to carry, has better cleaning capability and is a preferred toothbrush for people in travel.

However, most of mini electric toothbrushes on the market are directly driven by motors, so that the mini electric toothbrushes are high in energy consumption, short in endurance time, large in size, inconvenient to carry, low in vibration frequency, poor in comfort, not beneficial to removing dental plaque, high in vibration and high in manufacturing cost.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of this application is to provide a toothbrush power device and have its mini electric toothbrush, aim at solving mini electric toothbrush's among the prior art volume great, portable not, vibration frequency is lower simultaneously, the relatively poor technical problem of travelling comfort.

To achieve the above objects, according to one aspect of the present application, there is provided a toothbrush power device comprising: a main body; the electromagnetic driving part is fixedly arranged on the main body and comprises an electromagnet, the end part of the first end of the electromagnet is an electromagnetic control end, and the magnetic pole of the electromagnetic control end can be changed; the transmission part comprises a transmission shaft, the transmission shaft is movably arranged in the main body in a penetrating mode, a magnet is arranged at the first end of the transmission shaft, two magnetic poles of the magnet are arranged along the motion direction of the transmission shaft, the magnetic pole, far away from the transmission shaft, of the magnet is opposite to the electromagnetic control end, and the second end of the transmission shaft is used for being connected with the brush head assembly; the supporting part, supporting part fixed mounting are in the main part, and the inside of supporting part is provided with the through-hole, is provided with the convex part on the through-hole inner wall, and the second end of transmission shaft is worn to establish in the through-hole to with convex part interference fit.

Optionally, the transmission shaft, the magnet and the electromagnetic drive portion are coaxially arranged.

Optionally, the supporting portion is a circular truncated cone support frame, the through hole is located in the circular truncated cone support frame and is coaxially arranged with the circular truncated cone support frame, the protruding portion comprises a plurality of bosses, the plurality of bosses are arranged at intervals along the circumferential direction of the through hole, and the side wall of the transmission shaft is in interference fit with the side walls of the plurality of bosses.

Optionally, the transmission shaft is a quadrangular prism, the number of the bosses is four, recesses are arranged on the inner side of each boss, the four recesses are in interference fit with the four edges of the transmission shaft respectively, and the recesses are matched with the edges of the transmission shaft corresponding to the recesses.

Optionally, the thickness of the boss is 0.3 mm-1 mm; the width of the cross section of the part of the transmission shaft, which is positioned between the bosses, is 1 mm-2 mm, and the height is 3 mm-5 mm; the ratio of the distance between the first end of the transmission shaft and the boss to the distance between the second end of the transmission shaft and the boss is 1-2.

Optionally, the distance between the magnet and the electromagnetic control end is 0.3mm to 0.8 mm.

Optionally, one end of the main body, which is close to the brush head assembly, is provided with an end plate, the end plate is provided with a guide groove, the second end of the transmission shaft is arranged in the guide groove in a penetrating manner, and the support portion is fixed on the outer side of the end plate.

According to another aspect of the present application, a mini electric toothbrush is provided, the mini electric toothbrush comprises a brush head assembly, a brush holder housing and a toothbrush power device, the toothbrush power device is the above toothbrush power device, the brush head assembly is sleeved at the second end of the transmission shaft, and the toothbrush power device is fixedly installed in the brush holder housing.

Optionally, the brush holder shell comprises a body and a top cover, wherein an opening is formed in one end of the body, which is far away from the brush head assembly, the toothbrush power device can be installed into the body from the opening, and the top cover is covered on the opening and is pressed against the main body; one end of the body, which is close to the brush head assembly, is provided with a yielding hole, and the second end of the transmission shaft penetrates out of the yielding hole.

Optionally, a sealing part is arranged between one end of the body close to the brush head assembly and the supporting part.

The application provides a toothbrush power device's beneficial effect lies in: compared with the prior art, when the toothbrush power device provided by the application is used for driving an electric toothbrush, alternating current is firstly input to the electromagnet in the electromagnetic driving part through a direct-current power supply, the electromagnetic control end on the electromagnet can output an alternating magnetic field, then under the action of the alternating magnetic field, the magnet positioned on the first end of the transmission shaft can drive the transmission shaft to do reciprocating linear motion through a magnetic pole far away from the transmission shaft, when the transmission shaft does the reciprocating linear motion, the convex part which is arranged on the inner wall of the through hole of the supporting part and is in interference fit with the second end of the transmission shaft can generate corresponding elastic deformation along with the motion of the transmission shaft, and the brush head assembly connected with the second end of the transmission shaft can also vibrate along with the convex part; the vibration amplitude and the vibration frequency of the brush head assembly can be controlled by controlling the magnitude of the input current of the direct current power supply and the frequency of the alternating current; the toothbrush power device provided by the application occupies a small volume, has a long endurance time and can enable the brush head assembly to reach a high vibration frequency.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a cross-sectional view of a mini toothbrush provided in an embodiment of the present application;

FIG. 2 is an exploded view of a mini toothbrush provided in an embodiment of the present application;

FIG. 3 is a schematic structural view of a circular truncated cone support provided in an embodiment of the present application;

FIG. 4 is a cross-sectional view of a circular truncated cone support frame provided in an embodiment of the present application;

FIG. 5 is a cross-sectional view of a circular truncated cone support frame according to an embodiment of the present application;

reference numerals referred to in the above figures are detailed below:

10. a main body; 11. an end plate; 111. a guide groove; 20. an electromagnet; 21. an electromagnetic control end; 30. a drive shaft; 31. a magnet; 40. a circular truncated cone support frame; 41. a through hole; 411. a boss; 4111. a recess; 50. a brush head assembly; 60. a sealing part; 70. a brush handle shell; 71. a body; 711. an opening; 712. a hole of abdication; 72. and a top cover.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element. The embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

As mentioned in the background art, the conventional electric toothbrush is a tooth cleaning tool which can instantly decompose toothpaste into fine foam and deeply clean slits between teeth by causing a brush head to generate high-frequency vibration through the rapid rotation or vibration of a motor core, and is widely used in daily life of people due to excellent cleaning capability and comfortable cleaning experience; however, most of mini electric toothbrushes on the market are directly driven by motors, so that the mini electric toothbrushes are high in energy consumption, short in endurance time, large in size, inconvenient to carry, low in vibration frequency, poor in comfort, not beneficial to removing dental plaque, high in vibration and high in manufacturing cost.

Referring to fig. 1 to 5, in order to solve the above-mentioned problems, according to one aspect of the present application, an embodiment of the present application provides a toothbrush power device including: the electromagnetic driving device comprises a main body 10, an electromagnetic driving part, a transmission part and a supporting part, wherein the electromagnetic driving part is fixedly arranged on the main body 10 and comprises an electromagnet 20, the end part of the first end of the electromagnet 20 is an electromagnetic control end 21, and the magnetic pole of the electromagnetic control end 21 can be changed; the transmission part comprises a transmission shaft 30, the transmission shaft 30 is movably arranged in the main body 10 in a penetrating way, a first end of the transmission shaft 30 is provided with a magnet 31, two magnetic poles of the magnet 31 are arranged along the motion direction of the transmission shaft 30, the magnetic pole of the magnet 31 far away from the transmission shaft 30 is arranged opposite to the electromagnetic control end 21, and a second end of the transmission shaft 30 is used for connecting the brush head assembly 50; the supporting portion is fixedly installed on the main body 10, a through hole 41 is formed in the supporting portion, a convex portion is arranged on the inner wall of the through hole 41, and the second end of the transmission shaft 30 penetrates through the through hole 41 and is in interference fit with the convex portion. When the toothbrush power device provided by the embodiment is used for driving an electric toothbrush, firstly, alternating current is input to the electromagnet 20 in the electromagnetic driving part through a direct current power supply, at the moment, the electromagnetic control end 21 on the electromagnet 20 outputs an alternating magnetic field, then, under the action of the alternating magnetic field, the magnet 31 positioned on the first end of the transmission shaft 30 drives the transmission shaft 30 to do reciprocating linear motion through a magnetic pole far away from the transmission shaft 30, the convex part which is arranged on the inner wall of the through hole 41 of the supporting part and is in interference fit with the second end of the transmission shaft 30 generates corresponding elastic deformation along with the motion of the transmission shaft 30 while the transmission shaft 30 does the reciprocating linear motion, and the brush head assembly 50 connected with the second end of the transmission shaft 30 also vibrates along with the convex part; by controlling the magnitude of the input current of the dc power supply and the frequency of the alternating current, the vibration amplitude and frequency of the brushhead assembly 50 can be controlled; the toothbrush power device provided by the embodiment has the advantages that the occupied volume is small, the endurance time is long, and the brush head assembly 50 can reach high vibration frequency; the second end of the transmission shaft 30 is arranged in the through hole 41 in a penetrating mode and is in interference fit with the convex part, so that the integrity of the toothbrush power device can be effectively improved, and the reliability of a product is improved.

In a preferred embodiment, the magnet 31 of the present embodiment is glued to fixedly connect the magnet 31 to the first end of the transmission shaft 30.

In a specific embodiment, the electromagnet 20 in this embodiment is powered by a dc power supply, after being powered on, the center of the coil of the electromagnet 20 generates a magnetic field and magnetizes the iron core inside the electromagnet 20, when the coil of the electromagnet 20 is powered in the forward direction, the electromagnetic control end 21 of the electromagnet 20 charges the N pole, when the coil of the electromagnet 20 is powered in the reverse direction, the electromagnetic control end 21 of the electromagnet 20 charges the S pole, and by inputting an alternating current, the coil of the electromagnet 20 can generate an alternating magnetic field, and the polarity of the electromagnetic control end 21 of the electromagnet 20 is rapidly switched between the N pole and the S pole; the polarity of the end of the magnet 31, which faces the electromagnet 20, provided corresponding to the electromagnet 20 is S-pole or N-pole; when the polarity of the electromagnetic control terminal 21 is rapidly switched between the N pole and the S pole, the magnet 31 is continuously attracted or repelled, so that the transmission shaft 30, which is coaxial with and fixedly connected to the magnet 31, is linearly vibrated in a reciprocating manner.

Referring to fig. 1 and 2, in order to effectively reduce the vibration generated by the toothbrush power device during operation and to make the movement of the toothbrush power device more stable, the transmission shaft 30, the magnet 31 and the electromagnetic driving part are coaxially arranged in the embodiment. Through with transmission shaft 30, magnet 31 and the coaxial setting of electromagnetic drive portion, can make the electromagnetic drive portion through the effectual power of carrying of alternating magnetic field to magnet 31 on, also the effectual vibration that produces of reduction transmission in-process simultaneously to make the first end and the smooth compound linear vibration that carries on of transmission shaft 30 of 31 fixed connection of magnet.

Referring to fig. 3 to 5, in order to effectively improve the reliability of the product, the supporting portion in this embodiment is a circular truncated cone support frame 40, the through hole 41 is located in the circular truncated cone support frame 40 and is coaxially arranged with the circular truncated cone support frame 40, the protruding portion includes a plurality of bosses 411, the plurality of bosses 411 are arranged at intervals along the circumferential direction of the through hole 41, and the side wall of the transmission shaft 30 is in interference fit with the side walls of the plurality of bosses 411. Through set up a plurality of bosss 411 in the through-hole 41 of coaxial setting with round platform support frame 40 internal peripheral interval to make the lateral wall of transmission shaft 30 and the lateral wall interference fit of a plurality of bosss 411, can make the effectual fixed connection of transmission shaft 30 on round platform support frame 40, thereby the effectual wholeness that improves toothbrush power device, and then improve the reliability of product.

Referring to fig. 1 to 5, in order to effectively improve the reliability of the product, the transmission shaft 30 in this embodiment is a quadrangular prism, the number of the bosses 411 is four, the inner side of the boss 411 is provided with a concave portion 4111, the four concave portions 4111 are respectively in interference fit with four edges of the transmission shaft 30, and the concave portion 4111 is matched with the corresponding edge of the transmission shaft 30. The transmission shaft 30 is arranged to be a quadrangular prism, the bosses 411 are arranged to be four, the inner sides of the bosses 411 are provided with the concave portions 4111 matched with the edges of the transmission shaft 30, and the four concave portions 4111 are in interference fit with the four edges of the transmission shaft 30 respectively, so that the transmission shaft 30 is effectively and fixedly connected to the circular truncated cone support frame 40, the integrity of the toothbrush power device is effectively improved, and the reliability of a product is effectively improved.

In a preferred embodiment, the thickness of the boss 411 in this embodiment is 0.3mm to 1 mm; the width of the cross section of the part of the transmission shaft 30, which is positioned between the plurality of bosses 411, is 1mm to 2mm, and the height is 3mm to 5 mm; the ratio of the distance between the first end of the transmission shaft 30 and the boss 411 to the distance between the second end of the transmission shaft 30 and the boss 411 is 1-2. The width and length directions of the cross section of the transmission shaft 30 correspond to the width and length directions of the through hole 41, respectively, and the thickness of the boss 411 is set to be 0.3mm to 1 mm; the width of the cross section of the part of the transmission shaft 30, which is positioned between the bosses 411, is set to be 1 mm-2 mm, and the height is set to be 3 mm-5 mm; meanwhile, the ratio of the distance between the first end of the transmission shaft 30 and the boss 411 to the distance between the second end of the transmission shaft 30 and the boss 411 (i.e., the front-rear axis ratio) is 1-2, so that the driving frequency is 270Hz, and the frequency of a resonance system consisting of the brush head assembly 50, the transmission shaft 30, the circular table support frame 40 and the electromagnet 20 is matched with the driving frequency, thereby realizing lower power consumption, higher output energy and reducing vibration of the handle barrel, wherein table 1 is experimental data of several groups of embodiments, and several groups of experimental data with boss thicknesses of 0.3mm, 0.6mm and 1mm are preferred embodiments.

TABLE 1

In order to meet the production and processing requirements and obtain the required electromagnetic force, the distance between the magnet 31 and the electromagnetic control end 21 in the embodiment is 0.3 mm-0.8 mm. By setting the distance between the magnet 31 and the electromagnetic control end 21 to be 0.3 mm-0.8 mm, the theoretical electromagnetic force can be maximized on the premise of the same current, and the requirements of processing and production can be met.

Referring to fig. 1 and 2, in order to effectively limit the axial direction of the transmission shaft 30, in the embodiment, an end plate 11 is disposed at one end of the main body 10 close to the brush head assembly 50, a guide groove 111 is disposed on the end plate 11, a second end of the transmission shaft 30 is inserted into the guide groove 111, and the support portion is fixed at the outer side of the end plate 11. The end plate 11 is arranged at one end of the main body 10 close to the brush head assembly 50, the guide groove 111 is formed in the end plate 11, the second end of the transmission shaft 30 penetrates through the guide groove 111, and the supporting portion is fixed on the outer side of the end plate 11, so that the axial direction of the penetrating transmission shaft can be effectively limited.

Referring to fig. 1 to 5, according to another aspect of the present application, a mini electric toothbrush is provided, which comprises a brush head assembly 50, a handle housing 70 and a toothbrush power device, wherein the toothbrush power device is the toothbrush power device in the above embodiments, the brush head assembly 50 is sleeved on the second end of the transmission shaft 30, and the toothbrush power device is fixedly installed in the handle housing 70. When the mini electric toothbrush of this embodiment is assembled, the toothbrush power device is first installed inside the handle housing 70, and then the brush head assembly is installed at the second end of the transmission shaft 30 in the toothbrush power device, so that the mini electric toothbrush of this embodiment is completely installed, the mini electric toothbrush of this embodiment has a small volume and a long endurance time, and the brush head assembly 50 can reach a high vibration frequency, so that the mini electric toothbrush can effectively clean teeth.

In order to facilitate the assembly of the mini electric toothbrush, the brush holder shell 70 in this embodiment comprises a body 71 and a top cover 72, wherein an opening 711 is formed at one end of the body 71 away from the brush head assembly 50, the toothbrush power device can be loaded into the body 71 from the opening 711, and the top cover 72 is covered on the opening 711 and presses against the main body 10; one end of the body 71 near the brush head assembly 50 is provided with an abdicating hole 712, and the second end of the transmission shaft 30 penetrates out of the abdicating hole 712. When the mini electric toothbrush provided by this embodiment is assembled, the toothbrush power device is first installed in the body 71 of the handle housing 70 through the opening 711 provided at the end of the handle housing 70 body 71 away from the head assembly 50, while the toothbrush power device is installed in the body 71 of the handle housing 70 through the opening 711 provided at the end of the handle housing 70 body 71 away from the head assembly 50, the second end of the transmission shaft 30 gradually passes through the abdicating hole 712 provided at the end of the body 71 close to the head assembly 50 along with the installation of the toothbrush power device, after the installation of the toothbrush power device is completed, the top cover 72 is covered on the opening 711, and finally the head set is installed at the second end of the transmission shaft 30 in the toothbrush power device, at this time, the mini electric toothbrush provided by this embodiment is completely installed, the volume of the mini electric toothbrush provided by this embodiment is small, the duration of the flight is longer and the brushhead assembly 50 can reach a higher vibration frequency, thereby allowing the mini power toothbrush to effectively clean the teeth.

In order to achieve a better sealing effect of the mini electric toothbrush of this embodiment, a sealing portion 60 is disposed between one end of the body 71 close to the brush head assembly 50 and the supporting portion. The mini electric toothbrush can obtain better waterproof performance by arranging the sealing part 60 between one end of the body 71 close to the brush head assembly 50 and the supporting part, thereby effectively improving the reliability of the mini electric toothbrush.

In a preferred embodiment, the sealing portion 60 in this embodiment is a sealing ring, the sealing ring is disposed between the end of the main body 71 close to the brush head assembly 50 and the supporting portion, and the sealing ring is disposed between the end of the main body 71 close to the brush head assembly 50 and the supporting portion, so that the mini electric toothbrush can obtain better waterproof performance, and the reliability of the mini electric toothbrush can be effectively improved.

In summary, the toothbrush power device and the mini electric toothbrush having the same provided in the embodiment have at least the following beneficial effects: compared with the prior art, when the toothbrush power device provided by the embodiment is used for driving an electric toothbrush, firstly, alternating current is input to the electromagnet 20 in the electromagnetic driving part through a direct current power supply, at the moment, the electromagnetic control end 21 on the electromagnet 20 outputs an alternating magnetic field, then, under the action of the alternating magnetic field, the magnet 31 which is positioned on the first end of the transmission shaft 30 and corresponds to the electromagnetic control end 21 drives the transmission shaft 30 to do reciprocating linear motion through a magnetic pole which is far away from the transmission shaft 30, the convex part which is arranged on the inner wall of the through hole 41 of the supporting part and is in interference fit with the second end of the transmission shaft 30 generates corresponding elastic deformation along with the motion of the transmission shaft 30 while the transmission shaft 30 does the reciprocating linear motion, and the brush head assembly 50 connected with the second end of the transmission shaft 30 also generates vibration along with the convex part; by controlling the magnitude of the input current of the dc power supply and the frequency of the alternating current, the vibration amplitude and frequency of the brushhead assembly 50 can be controlled; the toothbrush power device provided by the embodiment occupies a small volume, has a long endurance time, and can enable the toothbrush head assembly 50 to reach a high vibration frequency.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.

Claims

1. A toothbrush power unit, characterized in that it comprises:

a main body (10);

the electromagnetic driving part is fixedly arranged on the main body (10) and comprises an electromagnet (20), the end part of the first end of the electromagnet (20) is an electromagnetic control end (21), and the magnetic pole of the electromagnetic control end (21) can be changed;

the transmission part comprises a transmission shaft (30), the transmission shaft (30) is movably arranged in the main body (10) in a penetrating mode, a magnet (31) is arranged at the first end of the transmission shaft (30), two magnetic poles of the magnet (31) are arranged along the motion direction of the transmission shaft (30), the magnetic pole, far away from the transmission shaft (30), of the magnet (31) is opposite to the electromagnetic control end (21), and the second end of the transmission shaft (30) is used for being connected with a brush head assembly (50);

the supporting part, the supporting part fixed mounting be in on main part (10), the inside of supporting part is provided with through-hole (41), be provided with the convex part on through-hole (41) inner wall, the second end of transmission shaft (30) is worn to establish in through-hole (41), and with convex part interference fit.

2. The toothbrush power unit according to claim 1, wherein the drive shaft (30), the magnet (31) and the electromagnetic drive section are coaxially disposed.

3. The toothbrush power device according to claim 1, wherein the supporting portion is a circular truncated cone supporting frame (40), the through hole (41) is located in the circular truncated cone supporting frame (40) and is coaxially arranged with the circular truncated cone supporting frame (40), the convex portion comprises a plurality of bosses (411), the plurality of bosses (411) are arranged at intervals along the circumferential direction of the through hole (41), and the side wall of the transmission shaft (30) is in interference fit with the side walls of the plurality of bosses (411).

4. A toothbrush power unit according to claim 3, characterized in that the drive shaft (30) is a quadrangular prism, the number of the bosses (411) is four, the inner side of the boss (411) is provided with a concave portion (4111), the four concave portions (4111) are respectively in interference fit with four edges of the drive shaft (30), and the concave portion (4111) is matched with the corresponding edge of the drive shaft (30).

5. The toothbrush power unit as claimed in claim 4, wherein the boss (411) has a thickness of 0.3mm to 1 mm; the width of the cross section of the part, located between the bosses (411), of the transmission shaft (30) is 1-2 mm, and the height of the cross section of the part is 3-5 mm; the ratio of the distance between the first end of the transmission shaft (30) and the boss (411) to the distance between the second end of the transmission shaft (30) and the boss (411) is 1-2.

6. A toothbrush power unit according to claim 5, characterized in that the distance between said magnet (31) and said electromagnetic control end (21) is comprised between 0.3mm and 0.8 mm.

7. The toothbrush power unit according to any one of claims 1 to 6, characterized in that an end of the main body (10) close to the brush head assembly (50) is provided with an end plate (11), the end plate (11) is provided with a guide groove (111), the second end of the transmission shaft (30) is inserted into the guide groove (111), and the support portion is fixed to the outer side of the end plate (11).

8. A mini electric toothbrush, characterized in that it comprises a brush head assembly (50), a handle housing (70) and a toothbrush power device, wherein the toothbrush power device is the toothbrush power device of any one of claims 1 to 7, the brush head assembly (50) is sleeved on the second end of the transmission shaft (30), and the toothbrush power device is fixedly mounted in the handle housing (70).

9. The mini electric toothbrush as recited in claim 8, wherein the handle housing (70) comprises a body (71) and a top cover (72), an end of the body (71) remote from the head assembly (50) is provided with an opening (711), the toothbrush power device can be loaded into the body (71) from the opening (711), the top cover (72) covers the opening (711) and presses against the main body (10); the one end that is close to of body (71) brush first subassembly (50) is provided with the hole of stepping down (712), the second end of transmission shaft (30) is followed the hole of stepping down (712) is worn out.

10. The mini electric toothbrush of claim 9, wherein a sealing portion (60) is provided between an end of the body (71) adjacent to the brushhead assembly (50) and the support portion.