Shaft sealing assembly, front-end waterproof assembly and main unit of handheld device

Abstract

The present application discloses a shaft sealing assembly, a front-end waterproof assembly and a main unit of a handheld device. The shaft sealing assembly of the handheld device comprises a central shaft and a movable sealing assembly, wherein the movable sealing assembly comprises a fixed base and a dynamic seal member; the fixed base is provided with a sleeve through-hole, an annular sealing groove is formed in the inner circumferential surface of the sleeve through-hole, and the sealing groove is provided with a front wall surface and a rear wall surface which are opposite in the axial direction; and the dynamic seal member is made of a flexible material, the dynamic seal member is arranged in the sleeve through-hole and extends into the sealing groove, the dynamic seal member is provided with a fixed shaft hole which is sealed with the central shaft and into which the central shaft is fixedly sleeved; and the dynamic seal member is respectively sealed with and rotatably fitted to the front wall surface and the rear wall surface. According to the present application, no abrasion is generated between the dynamic seal member and the central shaft, thereby improving the sealing effect.

Description

Shaft seal assembly, front waterproof assembly and main unit of handheld device Technical Field

[0001] The present application relates to the technical field of waterproofing of handheld devices, and in particular to a shaft sealing assembly, a front-end waterproofing assembly, and a main unit of a handheld device. Background Art

[0002] Due to their small size, waterproofing moving parts in handheld devices presents significant technical challenges. An electric toothbrush is a typical example of a handheld device. The moving central axis of the handheld device continuously abrades the waterproof seal, eventually causing the seal to fail and leak. Once the seal fails, external contaminants, such as toothpaste foam, can fill the gaps around the central axis and enter the internal cavity of the handle, causing the product to lose functionality.

[0003] In the past, electric toothbrushes rotated forward and reverse at a small angle to make the brush head vibrate, or used a magnetic levitation motor to drive the brush head to achieve vibration. This working method caused less wear on the seals due to the small amplitude of movement.

[0004] Today, handheld devices require the driving head to achieve greater rotational travel and higher-frequency forward and reverse switching. For example, electric toothbrushes require the brush head to move with greater amplitude for improved brushing effectiveness, or rotate 360 ​​degrees to clean the tongue. However, existing technology struggles to meet these new developments, resulting in a short waterproof lifespan for the central shaft and a high rate of product failure.

[0005] Summary of the Invention

[0006] The main purpose of this application is to propose a front-end waterproof component of a handheld device and a main unit of the handheld device, aiming to solve the technical problems that the shaft sealing component of the existing handheld device has a short waterproof life and is difficult to adapt to the central axis to operate with a larger rotation stroke and a higher forward and reverse switching frequency.

[0007] To achieve the above objectives, the shaft seal assembly of the handheld device proposed in this application includes:

[0008] central axis; and

[0009] A movable sealing assembly, comprising a fixed seat and a dynamic sealing member, wherein:

[0010] The fixing seat is provided with a sleeve through hole, and the inner circumference of the sleeve through hole is provided with an annular sealing groove, and the sealing groove has a front wall surface and a rear wall surface opposite to each other in the axial direction;

[0011] The dynamic seal is made of a flexible material, is arranged in the sleeve through hole and extends into the sealing groove, and is provided with a fixed shaft hole that is sealed with the central shaft and fixedly sleeved. The dynamic seal is respectively sealed with the front wall surface and the rear wall surface and can be rotatably matched.

[0012] Preferably, a gap is formed between the outer circumferential surface of the dynamic seal and the inner circumferential surface of the sealing groove, and the dynamic seal and the fixing seat enclose a sealed cabin located in the inner cavity of the sealing groove.

[0013] Preferably, the movable sealing assembly further comprises an oily sealing material filled in the sealing chamber, and the oily sealing material forms an oil seal interface between the dynamic seal and the front wall surface, and between the dynamic seal and the rear wall surface.

[0014] Preferably, the front end face of the dynamic seal is provided with a front annular protrusion on the periphery of the fixed shaft hole, and the front annular protrusion is sealed and rotatably matched with the front wall surface; the rear end face of the dynamic seal is provided with a rear annular protrusion on the periphery of the fixed shaft hole, and the rear annular protrusion is sealed and rotatably matched with the rear wall surface.

[0015] Preferably, the front wall surface and / or the rear wall surface is a high-gloss surface, and the friction coefficient thereof is smaller than the friction coefficient of the outer surface of the fixing seat.

[0016] Preferably, the dynamic seal is axially pre-pressed with the front wall surface and the rear wall surface respectively.

[0017] Preferably, the movable sealing assembly further comprises an annular clamp, which is sleeved on the outer peripheral surface of the dynamic seal, and the annular clamp is tightly fitted with the dynamic seal in the radial direction.

[0018] Preferably, an annular limiting groove is provided on the outer peripheral surface of the dynamic seal, and the annular clamp is provided in the limiting groove.

[0019] Preferably, the annular clamp is a coil spring, and the front and rear ends of the annular clamp are elastically in contact with the two side walls of the limiting groove that face each other in the axial direction.

[0020] Preferably, the fixing seat includes a base and a front cover fixedly connected to the base, the base and the front cover enclose the sleeve through hole and the sealing groove, the sleeve through hole includes a rear opening opened on the base and a front opening opened on the front cover, the front wall surface of the sealing groove is formed on the front cover, and the rear wall surface of the sealing groove is formed on the base.

[0021] Preferably, the axial interference between the dynamic seal and the fixing seat is [0.1%, 0.5%].

[0022] Preferably, the base includes a sealing cylinder, the inner circumferential surface of the sealing groove is formed on the sealing cylinder, and the inner wall surface of the front end of the sealing cylinder is provided with an annular groove; the front cover includes a cover plate and an inner stop, the cover plate covers the front opening of the sealing cylinder, the inner stop is annular and protrudes from the rear side of the cover plate, and the inner stop is adapted to fit in the annular groove.

[0023] Preferably, the dynamic seal is made of rubber or silicone; the base and the front cover are both made of plastic, and the rear end surface of the inner stop is fixed to the inner wall surface of the annular groove by ultrasonic welding.

[0024] Preferably, the outer circumferential surface of the inner stop is provided with an outer limiting plane, and the inner circumferential surface of the annular groove is provided with an inner limiting plane adapted to fit with the outer limiting plane.

[0025] Preferably, the base further comprises a positioning protrusion provided on the front end surface of the sealing cylinder, and the outer edge of the front cover is provided with a positioning groove adapted to the positioning protrusion.

[0026] Preferably, the positioning protrusion extends in the axial direction and protrudes from the outer peripheral surface of the sealing cylinder, and the inner wall surface of the static sealing component is provided with a slot adapted to the positioning protrusion.

[0027] The present application also proposes a front waterproof assembly for a handheld device, comprising:

[0028] A housing having a cavity formed therein, and a front end surface of the housing having a sealing hole communicating with the cavity;

[0029] A static sealing member, disposed in the sealing through hole and sealingly cooperating with the sealing through hole, the static sealing member being provided with a movable shaft hole communicating with the cavity; and

[0030] The shaft seal assembly of the handheld instrument as described above, wherein:

[0031] A central shaft is provided in the movable shaft hole and extends outward from the housing, wherein the central shaft is sealed and rotatably engaged with the movable shaft hole;

[0032] The movable sealing assembly is arranged in the cavity and located at the rear side of the static sealing component, and the fixing seat is fixedly arranged relative to the shell.

[0033] Preferably, the static seal has an annular sealing surface arranged rearward, and the annular sealing surface is formed on the periphery of the movable shaft hole; the front side surface of the fixing seat is in close contact with the annular sealing surface for sealing.

[0034] Preferably, the fixing seat and the static seal are tightly matched in the axial direction.

[0035] Preferably, the outer peripheral surface of the fixing seat is provided with a positioning protrusion extending in the axial direction, and the inner wall surface of the static sealing member is provided with a slot adapted to the positioning protrusion.

[0036] The present application also provides a main unit of a handheld device, comprising a handle and a motor;

[0037] The main body of the handheld device further comprises the shaft sealing assembly of the handheld device as described above, the central shaft is a part of the rotor of the motor, and the fixing seat is fixedly arranged relative to the handle; or

[0038] The host of the handheld device also includes the front waterproof component of the handheld device as described above, the handle is the shell, the motor is arranged in the cavity of the shell, and the central axis is a part of the rotor of the motor.

[0039] The shaft seal assembly of the handheld instrument of the present invention forms two seals on the front wall and the rear wall of the sealing groove through the dynamic seal and the fixed seat respectively, and the dynamic seal rotates with the central shaft. Therefore, no wear will be generated between the dynamic seal and the central shaft. In addition, by transferring the movable sealing interface to the dynamic seal, the sealing area is increased, the sealing effect is improved, and the waterproof life of the shaft seal assembly of the handheld instrument is extended, thereby reducing the after-sales maintenance rate of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0041] FIG1 is a schematic diagram of a front view of a partial structure of a front waterproof assembly of a handheld device according to an embodiment of the present invention;

[0042] FIG2 is a schematic diagram of the cross-sectional structure along line II-II in FIG1 ;

[0043] FIG3 is an exploded view of the local structure in FIG1 and a composite schematic diagram of the cross-sectional structure along line II-II;

[0044] FIG4 is an enlarged structural schematic diagram of the dynamic seal in FIG3 ;

[0045] FIG5 is a schematic diagram of the exploded structure of the local structure in FIG1 ;

[0046] FIG6 is an enlarged structural schematic diagram of the movable sealing assembly in FIG5;

[0047] FIG7 is a schematic diagram of the exploded structure of the partial structure in FIG1 from another angle;

[0048] FIG8 is an enlarged structural schematic diagram of the movable sealing assembly in FIG7;

[0049] FIG9 is a schematic diagram of the three-dimensional structure of a main body of a handheld device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] 1 to 8 , in one embodiment, a shaft sealing assembly of a handheld device is applied to a front waterproof assembly 200 of the handheld device. The shaft sealing assembly of the handheld device includes:

[0052] a central axis 30; and

[0053] The movable sealing assembly 40 includes a fixing seat 50 and a dynamic sealing member 60, wherein:

[0054] The fixing seat 50 is provided with a sleeve through hole 51, and the inner circumference of the sleeve through hole 51 is provided with an annular sealing groove 52, and the sealing groove 52 has a front wall surface 521 and a rear wall surface 522 opposite to each other in the axial direction;

[0055] The dynamic seal 60 is made of a flexible material. The dynamic seal 60 is arranged in the sleeve through hole 51 and extends into the sealing groove 52. The dynamic seal 60 is provided with a fixed shaft hole 61 that is sealed and fixedly sleeved with the central shaft 30. The dynamic seal 60 is respectively sealed with the front wall surface 521 and the rear wall surface 522 and can be rotatably matched.

[0056] In this embodiment, the dynamic seal 60 is generally made of a flexible material, such as rubber, silicone, etc.

[0057] The central shaft 30 serves as a connection and transmission mechanism. For example, in an embodiment of an electric toothbrush, the front end of the central shaft 30 is used to mount the brush head, while the rear end forms part of the motor rotor. It is understood that the central shaft 30 and the motor rotor can be provided separately, for example, with a transmission mechanism provided between them.

[0058] Since the fixing seat 50 needs to play the role of support and limitation, the fixing seat 50 is usually made of hard material, such as hard plastic, and the specific manufacturing process can be an injection molding process.

[0059] The sealing groove 52 cooperates with the dynamic sealing member 60 to form a closed space and ensure a sealing effect. Since the dynamic sealing member 60 also needs to be rotatably matched with the front wall surface 521 and the rear wall surface 522 of the sealing groove 52.

[0060] The front end waterproof assembly 200 of the handheld device of the present invention forms two seals on the front wall 521 and the rear wall 522 of the sealing groove 52 respectively through the dynamic seal 60 and the fixing seat 50, and the dynamic seal 60 rotates with the central shaft 30. Therefore, no wear will be generated between the dynamic seal 60 and the central shaft 30. In addition, by transferring the movable sealing interface to the dynamic seal 60, the sealing area is increased, the sealing effect is improved, and the waterproof life of the shaft sealing assembly of the handheld device is extended, thereby reducing the after-sales maintenance rate of the product.

[0061] Furthermore, a gap is formed between the outer circumference of the dynamic seal 60 and the inner circumference of the sealing groove 52, thereby reducing the friction between the dynamic seal 60 and the fixed seat 50. The dynamic seal 60 and the fixed seat 50 enclose a sealed cabin 70 located in the inner cavity of the sealing groove 52, so that existing substances in the sealed cabin 70, such as air, oil and other substances, can also serve as a barrier to invading stains.

[0062] Furthermore, the movable seal assembly 40 includes an oily sealing material filled in the sealing chamber 70. The oily sealing material forms oil-sealing interfaces between the dynamic seal 60 and the front wall 521, and between the dynamic seal 60 and the rear wall 522. In this embodiment, filling the sealing chamber 70 with the oily sealing material not only further reduces friction and thus wear, but also enhances the sealing effect by forming additional oil-sealing interfaces.

[0063] Furthermore, the front end face of the dynamic seal 60 is provided with a front annular protrusion 62 on the periphery of the fixed shaft hole 61, and the front annular protrusion 62 is sealed and rotatably matched with the front wall surface 521; the rear end face of the dynamic seal 60 is provided with a rear annular protrusion 63 on the periphery of the fixed shaft hole 61, and the rear annular protrusion 63 is sealed and rotatably matched with the rear wall surface 522.

[0064] In this embodiment, after the oil seal interface is formed, the contact area between the dynamic seal 60 and the inner wall surface of the sealing groove 52 is changed to annular protrusions, such as the front annular protrusion 62 and the rear annular protrusion 63. In this way, the friction force can be reduced by locally reducing the contact area without reducing the sealing effect, thereby reducing wear.

[0065] Furthermore, in order to reduce friction, the front wall surface 521 and the rear wall surface 522 of the sealing groove 52 are both high-gloss surfaces, and their friction coefficients are smaller than the friction coefficient of the outer surface of the fixing seat 50. For example, the front wall surface 521 and the rear wall surface 522 of the sealing groove 52 are smoother than the outer surface of the fixing seat 50; specifically, the friction coefficients of the front wall surface 521 and the rear wall surface 522 are both [0.05, 0.1].

[0066] Furthermore, the dynamic seal 60 is axially pre-pressed against the front wall 521 and the rear wall 522. In this embodiment, the elastic deformation of the dynamic seal 60 can be used to compensate for the axial gap caused by the filling vibration, thereby ensuring that the positive pressure required for sealing is greater than a preset threshold. Preferably, the axial interference between the dynamic seal 60 and the fixed seat 50 is [0.1%, 0.5%]. This can achieve the desired sealing effect while reducing the rotational resistance of the central shaft 30.

[0067] Furthermore, the movable sealing assembly 40 further includes an annular clamp 80 , which is sleeved on the outer circumferential surface of the dynamic seal 60 , and the annular clamp 80 and the dynamic seal 60 are tightly matched in the radial direction.

[0068] In this embodiment, the provision of the annular clamp 80 can enhance the fixing and sealing effect between the dynamic seal 60 and the central shaft 30. In addition, the radial pressure of the annular clamp 80 will force the dynamic seal 60 to deform in the axial direction, thereby better ensuring that the dynamic seal 60 is axially pre-pressed with the front wall surface 521 and the rear wall surface 522 respectively.

[0069] Furthermore, an annular limiting groove 64 is provided on the outer peripheral surface of the dynamic seal 60, and the annular clamp 80 is provided in the limiting groove 64, so that the annular clamp 80 is not easy to fall off from the dynamic seal 60, thereby facilitating integrated assembly and improving assembly efficiency.

[0070] Furthermore, the annular clamp 80 is a coil spring, and the front and rear ends of the annular clamp 80 are elastically in contact with the two side walls of the limiting groove 64 that face each other in the axial direction.

[0071] In this embodiment, the coil spring is a standard part, which is easy to obtain and low in cost. The annular clamp 80 is respectively in contact with the two side walls of the limiting groove 64 that are axially opposite to each other. On the one hand, it is not easy to loosen. On the other hand, the side walls of the limiting groove 64 can be turned outward, which is more conducive to the axial pre-pressing fit of the dynamic seal 60 with the front wall surface 521 and the rear wall surface 522 respectively.

[0072] Furthermore, the fixing seat 50 includes a base 53 and a front cover 57 fixedly connected to the base 53. The base 53 and the front cover 57 enclose a sleeve through hole 51 and a sealing groove 52. The sleeve through hole 51 includes a rear opening 54 opened on the base 53 and a front opening 581 opened on the front cover 57. The front wall surface 521 of the sealing groove 52 is formed on the front cover 57, and the rear wall surface 522 of the sealing groove 52 is formed on the base 53.

[0073] In this embodiment, since the overall size of the fixing base 50 is relatively small and the shape of the sealing groove 52 is not suitable for direct demolding, that is, it cannot be demolded in a single direction, the fixing base 50 is formed by connecting a split base 53 and a front cover 57. This can reduce the process cost of forming the inner cavity of the fixing base 50. For example, the base 53 and the front cover 57 are respectively formed by metal die-casting and then threaded or welded; or the base 53 and the front cover 57 are both made of plastic, and the two are fixed by ultrasonic welding or dispensing.

[0074] Furthermore, the base 53 includes a sealing cylinder 55, the inner circumferential surface of the sealing groove 52 being formed on the sealing cylinder 55, and the inner wall surface of the front end of the sealing cylinder 55 being provided with an annular groove 551; the front cover 57 includes a cover plate 58 and an inner stopper 59, the cover plate 58 covering the front opening of the sealing cylinder 55, the inner stopper 59 being annular and protruding from the rear side of the cover plate 58, and the inner stopper 59 being adapted to engage with the annular groove 551, thereby preventing the base 53 and the front cover 57 from being laterally misaligned. Preferably, the dynamic seal 60 is made of rubber or silicone; the base 53 and the front cover 57 are both made of plastic, and the rear end surface of the inner stopper 59 is ultrasonically welded to the inner wall surface of the annular groove 551. In this way, even if the dynamic seal 60 contacts the base 55 and the front cover 57, since the material of the seal 60 is different from that of the base 55 and the front cover 57, the seal 60 will not adhere to the base 55 and the front cover 57 during the ultrasonic welding process.

[0075] Furthermore, the outer circumferential surface of the inner stop 59 is provided with an outer limiting plane 591, and the inner circumferential surface of the annular groove 551 is provided with an inner limiting plane 552 that fits with the outer limiting plane, thereby preventing the front cover 57 from rotating relative to the base 53. Specifically in the ultrasonic welding process, the limiting structure that prevents rotation between the front cover 57 and the base 53 is conducive to improving the bonding efficiency.

[0076] Furthermore, the base 53 further includes a positioning protrusion 56 provided on the front end surface of the sealing cylinder 55 , and the outer edge of the front cover 57 is provided with a positioning groove 582 adapted to the positioning protrusion 56 .

[0077] In this embodiment, the positioning protrusion 56 and the positioning groove 582 cooperate to form a multi-level circumferential limit, so that the limit cooperation between the base 53 and the front cover 57 is more stable. In addition, since the positioning protrusion 56 and the positioning groove 582 are in a position that is easy to observe, the cooperation between the positioning protrusion 56 and the positioning groove 582 can also guide the outer limit plane 591 and the inner limit plane 552 to adapt and fit.

[0078] Furthermore, the positioning protrusion 56 extends axially and protrudes from the outer peripheral surface of the sealing tube 55, and the inner wall surface of the static seal 20 is provided with a slot 22 adapted to the positioning protrusion 56, thereby realizing the circumferential limitation of the base 53, which not only simplifies the relevant assembly structure, but also improves the structural strength of the positioning protrusion 56 itself. The front end of the positioning protrusion 56 can also be located radially farther outward, thereby increasing the fitting area between the cover plate 58 and the front end surface of the sealing tube 55.

[0079] Furthermore, the static seal 20 has a rearwardly facing annular sealing surface formed around the outer periphery of the movable shaft hole 21. The front side of the fixed seat 50 seals against the annular sealing surface, which can improve sealing performance in the transverse path. Preferably, the fixed seat 50 and the static seal 20 are tightly fitted in the axial direction, so that elastic deformation can compensate for any gaps that may occur during vibration.

[0080] Referring again to FIG. 1 to FIG. 8 , the present application further proposes a front waterproof assembly 200 of a handheld device, comprising:

[0081] The housing 10 has a cavity 11 formed therein, and a sealing hole 12 communicating with the cavity 11 is provided on the front face of the housing 10;

[0082] A static seal 20 is provided in the sealing through hole 12 and is in sealing cooperation with the sealing through hole 12 . The static seal 20 is provided with a movable shaft hole 21 communicating with the cavity 11 ; and

[0083] The shaft seal assembly of the handheld instrument as described above, wherein:

[0084] The central shaft 30 is passed through the movable shaft hole 21 and extends outward from the housing 10. The central shaft 30 and the movable shaft hole 21 are sealed and rotatably engaged.

[0085] The movable sealing assembly 40 is disposed in the cavity and located at the rear side of the static sealing component 20 , and the fixing seat 50 is fixed relative to the housing 10 .

[0086] In this embodiment, the housing 10 is used to provide support and protection for the components inside it. The housing 10 can be used only to install the sealing component and the transmission component, or it can also provide a holding function.

[0087] The static seal 20 and the dynamic seal 60 are usually made of flexible materials, such as rubber, silicone, etc. In order to improve the sealing effect, the inner wall surface of the movable shaft hole 21 can be provided with a plurality of annular protrusions for forming folds.

[0088] The specific structure of the shaft sealing assembly of the handheld device refers to the above embodiments. Since this electric toothbrush adopts all the technical solutions of all the above embodiments, it also has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0089] The central shaft 30 serves as a connection and transmission mechanism. For example, in an embodiment of an electric toothbrush, the front end of the central shaft 30 is used to mount the brush head, while the rear end forms part of the motor rotor. It is understood that the central shaft 30 and the motor rotor can be provided separately, for example, with a transmission mechanism provided between them.

[0090] The fixing base 50 can be directly fixedly connected to the housing 10, or can be fixed relative to the housing 10 by clamping other components with the housing 10. Because the fixing base 50 needs to provide support and limit, it is usually made of a hard material, such as hard plastic, and the specific manufacturing process can be an injection molding process.

[0091] The sealing groove 52 and the dynamic seal 60 cooperate to form a closed space and ensure a good sealing effect. Since the dynamic seal 60 also needs to rotatably cooperate with the front wall 521 and the rear wall 522 of the sealing groove 52, the front wall 521 and the rear wall 522 of the sealing groove 52 are both smooth surfaces, commonly known as high-gloss surfaces, to reduce friction.

[0092] The front end waterproof component 200 of the handheld device of the present invention can form an outer seal by setting a static seal 20, and form an inner seal by adding a movable seal component 40. Specifically, the dynamic seal 60 and the fixing seat 50 form two seals on the front wall 521 and the rear wall 522 of the sealing groove 52 respectively, and the dynamic seal 60 rotates with the central axis 30. Therefore, no wear will be generated between the dynamic seal 60 and the central axis 30, and the sealing area is increased by transferring the movable sealing interface to the dynamic seal 60, thereby improving the sealing effect, thereby extending the front end waterproof life of the handheld device and reducing the after-sales maintenance rate of the product.

[0093] Please refer to FIG9 , the present application also provides a main body 100 of a handheld device, including a handle and a motor (not shown);

[0094] The main body of the handheld device also includes the shaft sealing assembly of the handheld device as described above, the central shaft is part of the rotor of the motor, and the fixing seat is fixedly arranged relative to the handle; or

[0095] The main body of the handheld device also includes the front waterproof component of the handheld device as described above, the handle is a shell, the motor is arranged in the cavity of the shell, and the central axis is a part of the rotor of the motor.

[0096] In this embodiment, the main body of the handheld device can be the main body of the electric toothbrush shown in Figure 9, or a handheld device that performs the same function, such as an electric curling iron. The handle can provide support and protection for the internal components and provide a grip for the user. The motor is used to provide a power source for the movement of the central shaft 30. The specific structures of the shaft seal assembly of the handheld device and the front waterproof assembly 200 of the handheld device are similar to those of the above-mentioned embodiments. Since this electric toothbrush adopts all the technical solutions of all the above-mentioned embodiments, it also has all the beneficial effects brought about by the technical solutions of the above-mentioned embodiments, and will not be detailed here.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A shaft seal assembly for a handheld device, characterized in that: include: Central axis; as well as A movable sealing assembly, the movable sealing assembly comprising a fixed seat and a dynamic sealing member, wherein: The fixing seat is provided with a sleeve through hole, the inner circumference of the sleeve through hole is provided with an annular sealing groove, and the sealing groove has a front wall surface and a rear wall surface which are opposite to each other in the axial direction; The dynamic seal is made of a flexible material, is arranged in the sleeve through hole and extends into the sealing groove, is provided with a fixed shaft hole that is sealed with the central shaft and fixedly sleeved, and is respectively sealed with the front wall surface and the rear wall surface and can be rotatably matched.

2. The shaft seal assembly of the handheld instrument according to claim 1, characterized in that: A gap is formed between the outer circumferential surface of the dynamic seal and the inner circumferential surface of the sealing groove, and the dynamic seal and the fixing seat are enclosed to form a sealing cabin located in the inner cavity of the sealing groove.

3. The shaft seal assembly of the handheld instrument according to claim 2, characterized in that: The movable sealing assembly also includes an oily sealing material filled in the sealing chamber, and the oily sealing material forms an oil sealing interface between the dynamic seal and the front wall surface, and between the dynamic seal and the rear wall surface.

4. The shaft seal assembly of the handheld instrument according to claim 3, characterized in that: The front end face of the dynamic seal is provided with a front annular protrusion on the periphery of the fixed shaft hole, and the front annular protrusion is sealed and rotatably matched with the front wall surface; the rear end face of the dynamic seal is provided with a rear annular protrusion on the periphery of the fixed shaft hole, and the rear annular protrusion is sealed and rotatably matched with the rear wall surface.

5. The shaft seal assembly of a handheld device according to any one of claims 1 to 4, characterized in that: The front wall surface and / or the rear wall surface is a high-gloss surface, and the friction coefficient thereof is smaller than the friction coefficient of the outer surface of the fixing seat.

6. The shaft seal assembly of a handheld instrument according to claim 1, wherein: The dynamic seal is axially pre-pressed with the front wall surface and the rear wall surface respectively.

7. The shaft seal assembly of a handheld instrument according to claim 6, wherein: The movable sealing assembly further comprises an annular clamp, which is sleeved on the outer peripheral surface of the dynamic seal, and the annular clamp is tightly matched with the dynamic seal in the radial direction.

8. The shaft seal assembly of a handheld instrument according to claim 7, wherein: The outer peripheral surface of the dynamic seal is provided with an annular limiting groove, and the annular clamp is arranged in the limiting groove.

9. The shaft seal assembly of a handheld instrument according to claim 8, wherein: The annular clamp is a coil spring, and the front and rear ends of the annular clamp are elastically abutted against the two side walls of the limiting groove that face each other in the axial direction.

10. The shaft seal assembly of a handheld instrument according to any one of claims 6 to 9, characterized in that: The axial interference between the dynamic seal and the fixed seat is [0.1%, 0.5%].

11. The shaft seal assembly of a handheld instrument according to claim 1, wherein: The fixing seat includes a base and a front cover fixedly connected to the base, the base and the front cover enclose the sleeve via and the sealing groove, the sleeve via includes a rear opening opened in the base and a front opening opened in the front cover, the front wall surface of the sealing groove is formed in the front cover, and the rear wall surface of the sealing groove is formed in the base.

12. The shaft seal assembly of a handheld instrument according to claim 11, wherein: The base includes a sealing cylinder, the inner circumferential surface of the sealing groove is formed on the sealing cylinder, and the inner wall surface of the front end of the sealing cylinder is provided with an annular groove; the front cover includes a cover plate and an inner stopper, the cover plate covers the front opening of the sealing cylinder, the inner stopper is annular and protrudes on the rear side of the cover plate, and the inner stopper is adapted to fit in the annular groove.

13. The shaft seal assembly of a handheld instrument according to claim 12, wherein: The dynamic seal is made of rubber or silicone; the base and the front cover are both made of plastic, and the rear end surface of the inner stop is fixed to the inner wall surface of the annular groove by ultrasonic welding.

14. A shaft seal assembly for a handheld instrument according to claim 12 or 13, characterized in that: The outer circumferential surface of the inner stop is provided with an outer limiting plane, and the inner circumferential surface of the annular groove is provided with an inner limiting plane adapted to fit with the outer limiting plane.

15. The handheld instrument shaft seal assembly of claim 12, wherein: The base also includes a positioning protrusion arranged on the front end surface of the sealing cylinder, and the outer edge of the front cover is provided with a positioning groove adapted to the positioning protrusion.

16. The handheld instrument shaft seal assembly of claim 15, wherein: The positioning protrusion extends axially and protrudes from the outer peripheral surface of the sealing cylinder, and the inner wall surface of the static sealing component is provided with a slot adapted to the positioning protrusion.

17. A front waterproof component of a handheld device, characterized in that: include: A shell body having a cavity formed therein, and a sealing hole communicating with the cavity is provided on a front end surface of the shell body; A static sealing member, disposed in the sealing through hole and sealingly matched with the sealing through hole, wherein the static sealing member is provided with a movable shaft hole communicating with the cavity; as well as The shaft seal assembly of a handheld instrument according to any one of claims 1 to 16, wherein: A central shaft is passed through the movable shaft hole and extends outward from the housing, and the central shaft is sealed and rotatably matched with the movable shaft hole; The movable sealing component is arranged in the cavity and is located at the rear side of the static sealing component, and the fixing seat is fixedly arranged relative to the shell.

18. The front waterproof assembly of the handheld device according to claim 17, characterized in that: The static seal has an annular sealing surface arranged rearwardly, and the annular sealing surface is formed on the periphery of the movable shaft hole; the front side surface of the fixing seat is in close contact with the annular sealing surface for sealing.

19. The front waterproof assembly of the handheld device as claimed in claim 18, characterized in that: The fixing seat is tightly matched with the static sealing component in the axial direction.

20. The front waterproof assembly of a handheld device according to any one of claims 17 to 19, characterized in that: The outer peripheral surface of the fixing seat is provided with a positioning protrusion extending in the axial direction, and the inner wall surface of the static sealing member is provided with a slot adapted to the positioning protrusion.

21. A main unit of a handheld device, comprising a handle and a motor; characterized in that: The host of the handheld device further comprises a shaft sealing assembly of the handheld device as claimed in any one of claims 1 to 16, the central axis is a part of the rotor of the motor, and the fixing seat is fixedly arranged relative to the handle; or The host of the handheld device also includes a front waterproof component of the handheld device as described in any one of claims 17-20, the handle is the shell, the motor is arranged in the cavity of the shell, and the central axis is a part of the rotor of the motor.

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