Shaft sealing assembly of handheld device, front end waterproof assembly, and host device

Abstract

To provide a shaft sealing assembly, a front-end waterproof assembly and a host device of a handheld device.SOLUTION: A shaft sealing assembly of a handheld device includes: a center shaft; and a movable sealing assembly, including a fixation seat and a movable sealing member. The fixation seat defines a sleeving hole, an inner circumferential surface of the sleeving hole defines an annular sealing slot, the sealing slot has a front wall surface and a rear wall surface opposite to the front wall surface in an axial direction. The movable sealing member is made of flexible material, the movable sealing member is received in the sleeving hole and extends into the sealing slot, the movable sealing member defines a fixation shaft hole which is sealed to and fixedly sleeves the center shaft, the movable sealing member is sealed to and rotatably mated to the front wall surface and the rear wall surface. No wear occurs between the movable seal member and the central shaft of the present application, and the sealing effect is improved.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This application relates to the field of waterproof technology for handheld appliances, and particularly to the shaft seal assembly, front-end waterproof assembly and body device of handheld appliances.

Background Art

[0002] Due to the relatively small size of handheld appliances, it is technically difficult to address the waterproofing of moving components. An electric toothbrush is a typical handheld appliance. The central axis around which it moves constantly wears down the waterproof sealing material, ultimately leading to seal failure and water leakage. When the seal fails, external dirt such as toothpaste foam fills the gap around the central axis and enters the internal hollow cavity of the handle, causing the product's functionality to malfunction.

[0003] Conventionally, an electric toothbrush rotates forward and backward at a small angle to fit the brush head to the vibration, or is driven by a magnetic levitation motor to achieve the vibration of the brush head. Such an operating method results in a relatively small wear of the sealing material due to the small movement range.

[0004] Currently, handheld appliances need to drive the operating head to switch with a larger rotation stroke and a higher frequency of forward and reverse rotation. For example, an electric toothbrush needs the driving brush head to move more significantly to enhance the toothbrushing effect, or needs to rotate 360 degrees to clean the tongue coating. However, the conventional technology has difficulty meeting the above newly developed technical requirements, leading to technical problems such as a short waterproof life of the central axis and a high after-sales service rate of the product.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The main object of the present application is to provide a front-end waterproof assembly for a handheld instrument and a body device of a handheld instrument to solve the technical problems that the waterproof life of the shaft seal assembly of a conventional handheld instrument is short and it is difficult to adapt to the operation of the central shaft with a larger rotation stroke and a higher forward and reverse switching frequency.

Means for Solving the Problems

[0007] In order to achieve the above object, the shaft seal assembly of the handheld instrument according to the present application includes a central shaft, and a movable seal assembly including a fixed seat and a movable sealing material, where a socket through hole is provided in the fixed seat, an annular seal groove is provided on the inner peripheral surface of the socket through hole, the seal groove has a front wall surface and a rear wall surface facing each other in the axial direction, the movable sealing material is made of a flexible material, the movable sealing material is provided in the socket through hole and protrudes into the seal groove, a fixed shaft hole is provided in the movable sealing material for sealing and fixedly sleeving on the central shaft, and the movable sealing material is sealed and rotatably fitted to the front wall surface and the rear wall surface respectively.

[0008] Preferably, a pitch is formed between the outer peripheral surface of the movable sealing material and the inner peripheral surface of the seal groove, and the movable sealing material and the fixed seat surround to form a seal chamber located in the cavity in the seal groove.

[0009] Preferably, the movable seal assembly further includes an oil-based seal material filled in the seal chamber, and the oil-based seal material forms an oil seal interface between the movable seal material and the front wall surface, and between the movable seal material and the rear wall surface.

[0010] Preferably, a front annular protrusion is provided around the fixed shaft hole on the front end face of the movable sealing material. The front annular protrusion is sealed to and rotatably fitted to the front wall surface. On the rear end face of the movable sealing material, a rear annular protrusion is provided around the fixed shaft hole. The rear annular protrusion is sealed to and rotatably fitted to the rear wall surface.

[0011] Preferably, the front wall surface and / or the rear wall surface is a high-gloss surface, and its coefficient of friction is smaller than that of the outer surface of the fixed seat.

[0012] Preferably, the movable sealing materials are axially pre-press-fitted to the front wall surface and the rear wall surface respectively.

[0013] Preferably, the movable seal assembly further includes an annular locking clip. The annular locking clip is externally fitted to the outer peripheral surface of the movable sealing material, and the annular locking clip and the movable sealing material are interference-fitted in the radial direction.

[0014] Preferably, an annular stopper groove is provided on the outer peripheral surface of the movable sealing material, and the annular locking clip is provided in the stopper groove.

[0015] Preferably, the annular locking clip is a coil spring. The front and rear ends of the annular locking clip are elastically abutted against the opposite side wall surfaces in the axial direction of the stopper groove respectively.

[0016] Preferably, the fixed seat includes a base and a front cover fixedly connected to the base. The base and the front cover enclose to form the socket through hole and the seal groove. The socket 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 seal groove is formed on the front cover, and the rear wall surface of the seal groove is formed on the base.

[0017] Preferably, the axial tightening allowance between the movable sealing material and the fixed seat is [0.1%, 0.5%].

[0018] Preferably, the base includes a seal cylinder, an inner circumferential surface of the seal groove is formed on the seal cylinder, an annular concave groove is provided on an inner wall surface at a front end of the seal cylinder, the front cover includes a cover plate and an inner stopper opening, the cover plate covers a front-side opening of the seal cylinder, the inner stopper opening is annular and protrudes from a rear surface of the cover plate, and the inner stopper opening is fitted in the annular concave groove in a conforming manner.

[0019] Preferably, the movable sealing material is made of rubber or silica gel, both the base and the front cover are made of plastic, and a rear end surface of the inner stopper opening is fixed by ultrasonic welding to an inner wall surface of the annular concave groove.

[0020] Preferably, an outer stopper plane is provided on an outer circumferential surface of the inner stopper opening, and an inner stopper plane that conforms to and is bonded to the outer stopper plane is provided on an inner circumferential surface of the annular concave groove.

[0021] Preferably, the base further includes a positioning protrusion provided on a front end surface of the seal cylinder, and a positioning concave groove that conforms to the positioning protrusion is provided on an outer edge of the front cover.

[0022] Preferably, the positioning protrusion extends along an axial direction and protrudes from an outer circumferential surface of the seal cylinder, and an insertion groove that conforms to the positioning protrusion is provided on an inner wall surface of the stationary sealing material.

[0023] This application further proposes a front-end waterproof assembly of a handheld device, and the front-end waterproof assembly of the handheld device includes a case in which an accommodation cavity is formed therein and a seal through-hole communicating with the accommodation cavity is provided on a front end surface, and a stationary sealing material provided in the seal through-hole and seal-fitted to the seal through-hole, and a movable shaft hole communicating with the accommodation cavity is provided, and the shaft seal assembly of the handheld device described above, where The central axis is formed in the movable shaft hole and extends outward from the case. The central axis is sealed in the movable shaft hole and is rotatably fitted therein. The movable seal assembly is provided in the accommodation cavity and is located on the rear side of the stationary sealing material. The fixed seat is fixedly installed with respect to the case.

[0024] Preferably, the stationary sealing material has an annular sealing surface installed backward. The annular sealing surface is formed around the movable shaft hole. The front surface of the fixed seat is bonded and sealed to the annular sealing surface.

[0025] Preferably, the fixed seat and the stationary sealing material are interference-fitted in the axial direction.

[0026] Preferably, positioning protrusions extending along the axial direction are provided on the outer peripheral surface of the fixed seat, and insertion grooves adapted to the positioning protrusions are provided on the inner wall surface of the stationary sealing material.

[0027] This application further proposes a main body device of a handheld instrument including a handle and a motor. The main body device of the handheld instrument further includes the shaft seal assembly of the handheld instrument described above. The central axis is a part of the rotor of the motor. The fixed seat is fixedly installed with respect to the handle, or The main body device of the handheld instrument further includes the front-end waterproof assembly of the handheld instrument described above. The handle is the case. The motor is provided in the accommodation cavity of the case. The central axis is a part of the rotor of the motor.

Advantages of the Invention

[0028] The shaft seal assembly of the handheld instrument of the present invention forms two seals on the front wall surface and the rear wall surface of the seal groove by a movable sealing material and a fixed seat respectively. Since the movable sealing material rotates along the central axis, wear does not occur between the movable sealing material and the central axis. By moving the movable seal interface to the movable sealing material, the seal area is increased, the sealing effect is improved, the waterproof life of the shaft seal assembly of the handheld instrument is further extended, and the after-maintenance rate of the product is reduced.

Brief Description of the Drawings

[0029] To more clearly explain the technical solutions in the embodiments of the present application, the following briefly introduces the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, based on these drawings, other drawings can be obtained without creative efforts.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0030] The following clearly and completely describes the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0031] Referring to FIGS. 1 to 8, in one embodiment, the shaft seal assembly of the handheld instrument is applied to the front-end waterproof assembly 200 of the handheld instrument. The shaft seal assembly of this handheld instrument includes a central shaft 30, and a movable seal assembly 40 including a fixed seat 50 and a movable sealing material 60. Here, a socket through hole 51 is provided in the fixed seat 50, and an annular seal groove 52 is provided on the inner peripheral surface of the socket through hole 51. The seal groove 52 has a front wall surface 521 and a rear wall surface 522 facing each other in the axial direction. The movable sealing material 60 is made of a flexible material. The movable sealing material 60 is provided in the socket through hole 51 and protrudes into the seal groove 52. The movable sealing material 60 is provided with a fixed shaft hole 61 that is sealed and fixedly sleeved on the central shaft 30. The movable sealing material 60 is sealed and rotatably fitted to the front wall surface 521 and the rear wall surface 522 respectively.

[0032] In this embodiment, the movable sealing material 60 generally adopts a flexible material, such as rubber, silica gel, etc.

[0033] The central shaft 30 is used to perform connection and transmission functions. For example, in an embodiment applied to an electric toothbrush, the front end of the central shaft 30 is used to mount the brush head, and the rear end forms a part of the motor rotor. As can be understood, the central shaft 30 and the motor rotor can be installed separately. For example, a transmission mechanism can be additionally installed between the two.

[0034] Since the fixed seat 50 needs to function as a support and a stopper, the fixed seat 50 is generally made of a hard material such as hard rubber, and the specific manufacturing process can adopt an injection molding process.

[0035] The seal groove 52 and the movable sealing material 60 can be fitted together to form a sealed space to ensure the sealing effect. The movable sealing material 60 also needs to be rotatably fitted to the front wall surface 521 and the rear wall surface 522 of the seal groove 52.

[0036] The front-end waterproof assembly 200 of the handheld instrument of the present invention forms two seals on the front wall surface 521 and the rear wall surface 522 of the seal groove 52 by the movable sealing material 60 and the fixed seat 50 respectively. Since the movable sealing material 60 rotates along the central axis 30, there is no wear between the movable sealing material 60 and the central axis 30, and the movable sealing interface is transferred to the movable sealing material 60 to increase the sealing area, improve the sealing effect, further extend the waterproof life of the shaft seal assembly of the handheld instrument, and reduce the after-maintenance rate of the product.

[0037] Furthermore, a pitch is formed between the outer peripheral surface of the movable sealing material 60 and the inner peripheral surface of the seal groove 52, so that the frictional force between the movable sealing material 60 and the fixed seat 50 can be reduced. The movable sealing material 60 and the fixed seat 50 enclose to form a seal chamber 70 located in the inner cavity of the seal groove 52, and thus can act as a barrier against existing substances in the seal chamber 70, such as substances such as air and oil and the dirt that has invaded.

[0038] Furthermore, the movable seal assembly 40 further includes an oil-based sealing material filled in the seal chamber 70. The oil-based sealing material forms an oil seal interface between the movable sealing material 60 and the front wall surface 521, and between the movable sealing material 60 and the rear wall surface 522. In this embodiment, by filling the oil-based sealing material in the seal chamber 70, the frictional force can be further reduced to further reduce wear, and a further oil seal interface can be formed to enhance the sealing effect.

[0039] Furthermore, on the front end face of the movable sealing member 60, a front annular protrusion 62 is provided around the fixed shaft hole 61. The front annular protrusion 62 is sealed to the front wall surface 521 and is rotatably fitted thereto. On the rear end face of the movable sealing member 60, a rear annular protrusion 63 is provided around the fixed shaft hole 61. The rear annular protrusion 63 is sealed to the rear wall surface 522 and is rotatably fitted thereto.

[0040] In this embodiment, after forming the oil seal interface, the contact portion between the movable sealing member 60 and the inner wall surface of the seal groove 52 is changed to annular protrusions, for example, the front annular protrusion 62 and the rear annular protrusion 63. In this way, without reducing the sealing effect, the contact area is locally reduced to reduce the frictional force and further reduce wear.

[0041] Furthermore, in order to reduce the frictional force, both the front wall surface 521 and the rear wall surface 522 of the seal groove 52 are high-gloss surfaces, and their friction coefficients are smaller than the friction coefficient of the outer surface of the fixed seat 50. For example, the front wall surface 521 and the rear wall surface 522 of the seal groove 52 are smoother than the outer surface of the fixed seat 50. Specifically, the friction coefficients of both the front wall surface 521 and the rear wall surface 522 are both in the range of [0.05, 0.1].

[0042] Furthermore, the movable sealing member 60 is axially pre-press fitted to the front wall surface 521 and the rear wall surface 522 respectively. In this embodiment, by utilizing the elastic deformation of the movable sealing member 60, the axial gap due to filling vibration can be compensated, and it is further ensured that the positive pressure required for sealing is greater than the preset threshold value. Preferably, the axial tightening allowance between the movable sealing member 60 and the fixed seat 50 is [0.1%, 0.5%]. In this way, the preset sealing effect is achieved, and the rotational resistance of the central shaft 30 can be reduced.

[0043] Furthermore, the movable seal assembly 40 further includes an annular locking clip 80. The annular locking clip 80 is externally fitted to the outer peripheral surface of the movable sealing member 60, and the annular locking clip 80 and the movable sealing member 60 are press-fitted with an interference fit in the radial direction.

[0044] In this embodiment, by installing the annular locking clip 80, the fixing of the movable sealing member 60 to the central axis 30 and the sealing effect can be enhanced. Moreover, the radial biasing of the annular locking clip 80 deforms the movable sealing member 60 in the axial direction, thereby better ensuring the axial pre-pressure fitting between the movable sealing member 60 and the front wall surface 521 and the rear wall surface 522 respectively.

[0045] Furthermore, an annular stopper groove 64 is provided on the outer peripheral surface of the movable sealing member 60, and the annular locking clip 80 is provided in the stopper groove 64. In this way, it is difficult for the annular locking clip 80 to fall off from the movable sealing member 60, thereby facilitating integral assembly and improving the assembly efficiency.

[0046] Furthermore, the annular locking clip 80 is a coil spring, and both the front and rear ends of the annular locking clip 80 are elastically abutted against the two side wall surfaces facing the axial direction of the stopper groove 64 respectively.

[0047] In this embodiment, the coil spring is a standard part, which is easy to obtain and has a low cost. When the annular locking clip 80 abuts against the two side wall surfaces facing the axial direction of the stopper groove 64 respectively, loosening is less likely to occur. On the other hand, the side wall of the stopper groove 64 bulges outwards, which is more advantageous for the axial pre-pressure fitting between the movable sealing member 60 and the front wall surface 521 and the rear wall surface 522 respectively.

[0048] Furthermore, the fixed 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 surround and form a socket-through hole 51 and a sealing groove 52. The socket-through hole 51 includes a rear opening 54 opened in the base 53 and a front opening 581 opened in 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.

[0049] In this embodiment, the overall size of the fixed seat 50 is relatively small, and the shape of the seal groove 52 is not suitable for direct die-casting molding, that is, it cannot be demolded in a single direction. Therefore, the fixed seat 50 is formed by connecting a separate base 53 and a front cover 57. In this way, the process cost of forming the inner cavity of the fixed seat 50 can be reduced. For example, the base 53 and the front cover 57 are respectively formed by metal die-casting and then connected by screws or welded, or both the base 53 and the front cover 57 are made of plastic materials and are fixed by ultrasonic welding or a dispenser.

[0050] Furthermore, the base 53 includes a seal cylinder 55. The inner peripheral surface of the seal groove 52 is formed on the seal cylinder 55. An annular concave groove 551 is provided on the inner wall surface at the front end of the seal cylinder 55. The front cover 57 includes a cover plate 58 and an inner stopper 59. The cover plate 58 covers the front opening of the seal cylinder 55. The inner stopper 59 is annular and protrudes from the rear surface of the cover plate 58. The inner stopper 59 is fitted into the annular concave groove 551 in a conforming manner. In this way, the base 53 and the front cover 57 are not easily displaced in the lateral direction. Preferably, the movable seal material 60 is made of rubber or silica gel. Both the base 53 and the front cover 57 are made of plastic materials. The rear end surface of the inner stopper 59 is ultrasonically welded to the inner wall surface of the annular concave groove 551. In this way, even when the movable seal material 60 contacts the base 55 and the front cover 57, since the material of the seal material 60 is different from that of the base 55 and the front cover 57, the seal material 60 will not adhere to the base 55 and the front cover 57 during the ultrasonic welding process.

[0051] Furthermore, an outer stopper plane 591 is provided on the outer peripheral surface of the inner stopper 59, and an inner stopper plane 552 that is adapted to and bonded to the outer stopper plane is provided on the inner peripheral surface of the annular concave groove 551. In this way, the front cover 57 is prevented from rotating relative to the base 53. Specifically, for the ultrasonic welding process, the stopper structure that prevents rotation between the front cover 57 and the base 53 is advantageous for enhancing the bonding efficiency.

[0052] Furthermore, the base 53 further includes a positioning protrusion 56 provided on the front end face of the seal cylinder 55, and a positioning concave groove 582 adapted to the positioning protrusion 56 is provided on the outer edge of the front cover 57.

[0053] In this embodiment, by fitting the positioning protrusion 56 and the positioning concave groove 582, multi-layer circumferential stoppers can be formed, thereby making the stopper fitting between the base 53 and the front cover 57 stronger. In addition, since the positioning protrusion 56 and the positioning concave groove 582 are at easily observable positions, the fitting of the positioning protrusion 56 and the positioning concave groove 582 can guide the conforming and bonding of the outer stopper plane 591 and the inner stopper plane 552.

[0054] Furthermore, the positioning protrusion 56 extends along the axial direction and protrudes from the outer peripheral surface of the seal cylinder 55, and an insertion groove 22 adapted to the positioning protrusion 56 is provided on the inner wall surface of the stationary seal member 20. When the circumferential stopper of the base 53 is realized in this way, not only the related assembly structure is simplified, but also the structural strength of the positioning protrusion 56 itself is improved. The front end of the positioning protrusion 56 can be at a position farther outward in the radial direction, and in this way, the bonding area between the cover plate 58 and the front end face of the seal cylinder 55 can be increased.

[0055] Furthermore, the stationary seal member 20 has an annular seal surface installed backward, and the annular seal surface is formed around the movable shaft hole 21. The front side surface of the fixed seat 50 is bonded and sealed to the annular seal surface, for example, the sealing performance of the lateral path can be enhanced. Preferably, the fixed seat 50 and the stationary seal member 20 are interference-fitted in the axial direction, and in this way, the gaps that may occur during vibration can be supplemented by elastic deformation.

[0056] Please refer to FIGS. 1 to 8 again. The present application further proposes a front-end waterproof assembly 200 of a handheld device, and this front-end waterproof assembly 200 of the handheld device is A case 10 is formed with an accommodation cavity 11 inside, and a seal through hole 12 communicating with the accommodation cavity 11 is provided on the front end face. A stationary seal member 20 is provided in the seal through hole 12 and is seal-fitted to the seal through hole 12, and a movable shaft hole 21 communicating with the accommodation cavity 11 is provided. It includes the shaft seal assembly of the handheld instrument described above, where The central shaft 30 is drilled in the movable shaft hole 21 and extends out of the case 10 to the outside. The central shaft 30 is sealed in the movable shaft hole 21 and is rotatably fitted. The movable seal assembly 40 is provided in the accommodation cavity and is located on the rear side of the stationary seal member 20. The fixed seat 50 is fixedly installed with respect to the case 10.

[0057] In this embodiment, the case 10 is used to provide support and protection for the internal members. The case 10 can be used only for the installation of the seal assembly and the transmission assembly, and can also provide a gripping function.

[0058] Generally, flexible materials such as rubber and silica gel are adopted for the stationary seal member 20 and the movable seal member 60. In order to enhance the sealing effect, a plurality of annular protrusions for forming wrinkles may be provided on the inner wall surface of the movable shaft hole 21.

[0059] For the specific structure of the shaft seal assembly of the handheld instrument, referring to the above embodiment, since this electric toothbrush adopts all the technical solutions of all the above embodiments, it similarly has all the beneficial effects of the technical solutions of the above embodiments, and will not be described in detail here.

[0060] The central shaft 30 is used to perform connection and transmission functions. For example, in an embodiment applied to an electric toothbrush, the front end of the central shaft 30 is used to attach the brush head, and the rear end forms a part of the motor rotor. As can be understood, the central shaft 30 and the motor rotor can be installed separately. For example, a transmission mechanism can be additionally installed between the two.

[0061] The fixed seat 50 may be directly fixedly connected to the case 10, or may be fixedly installed with respect to the case 10 by a method such as nipping between the case 10 and other members. Since the fixed seat 50 needs to function as a support and a stopper, the fixed seat 50 is generally made of a hard material, such as hard rubber, and a specific manufacturing process can adopt an injection molding process.

[0062] The fitting of the seal groove 52 and the movable sealing material 60 can form a sealed space to ensure the sealing effect. Since the movable sealing material 60 needs to be rotatably fitted to the front wall surface 521 and the rear wall surface 522 of the seal groove 52, in order to reduce the frictional force, both the front wall surface 521 and the rear wall surface 522 of the seal groove 52 are smooth surfaces, that is, generally referred to as high-gloss surfaces.

[0063] The front-end waterproof assembly 200 of the handheld instrument of the present invention can form an outer seal by installing the stationary sealing material 20 and can form an inner seal by adding the movable seal assembly 40. Specifically, the movable sealing material 60 and the fixed seat 50 respectively form two seals on the front wall surface 521 and the rear wall surface 522 of the seal groove 52. Since the movable sealing material 60 rotates along the central axis 30, wear does not occur between the movable sealing material 60 and the central axis 30, and the movable sealing interface is transferred to the movable sealing material 60 to increase the sealing area, improve the sealing effect, further extend the waterproof life of the front end of the handheld instrument, and reduce the after-maintenance rate of the product.

[0064] Please also refer to FIG. 9. The present application further proposes a main body device 100 of a handheld instrument including a handle and a motor (not shown). The main body device of the handheld instrument further includes the shaft seal assembly of the handheld instrument described above. The central axis is a part of the rotor of the motor. The fixed seat is fixedly installed with respect to the handle, or The main body device of the handheld appliance further includes the front-end waterproof assembly of the handheld appliance described above. The handle is a case, the motor is provided in the accommodation cavity of the case, and the central axis is part of the rotor of the motor.

[0065] In this embodiment, the main body device of the handheld appliance may be the main body device of the electric toothbrush shown in FIG. 9, or may be a handheld appliance with its functions, such as an electric hair iron. The handle can provide the functions of supporting and protecting its internal components, and can also provide a gripping function for the user. The motor is used to provide a power source for the movement of the central axis 30. For the specific structures of the shaft seal assembly of the handheld appliance and the front-end waterproof assembly 200 of the handheld appliance, refer 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 according to the technical solutions of the above embodiments, and will not be described in detail here.

[0066] Finally, it should be noted that the above embodiments are only for explaining the technical solutions of this application and do not limit them. Although this application has been described in detail with reference to the foregoing embodiments, as can be understood by those skilled in the art, it is still possible to modify the technical solutions described in each of the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements do not depart from the spirit and scope of the technical solutions of each embodiment of this application for the corresponding technical solutions.

Claims

1. 1. A shaft seal assembly for a handheld instrument, comprising: A central axis, a movable seal assembly including a fixed seat and a movable seal member, wherein: The fixed seat has a through hole, and an annular seal groove is formed on an inner peripheral surface of the through hole, the seal groove having a front wall surface and a rear wall surface opposed to each other in an axial direction; The movable seal is made of a flexible material, the movable seal is provided in the bushing through hole and protrudes into the seal groove, the movable seal has a fixed shaft hole which is sealed and fixedly bushed to the central shaft, and the movable seal is sealed to the front wall surface and the rear wall surface, respectively, and rotatably fitted thereto.

2. 2. The axial seal assembly of claim 1, wherein a pitch is formed between an outer peripheral surface of the movable seal and an inner peripheral surface of the seal groove, and the movable seal and the fixed seat together form a seal chamber located in a cavity within the seal groove.

3. 3. The axial seal assembly of claim 2, wherein the movable seal assembly further comprises an oily sealing material filled in the seal chamber, the oily sealing material forming an oil sealing interface between the movable seal and the front wall surface and between the movable seal and the rear wall surface.

4. 4. The axial seal assembly of a hand-held instrument as described in claim 3, characterized in that a front end surface of the movable seal is provided with a front annular protrusion around the fixed axial hole, the front annular protrusion being sealed and rotatably fitted to the front wall surface, and a rear end surface of the movable seal is provided with a rear annular protrusion around the fixed axial hole, the rear annular protrusion being sealed and rotatably fitted to the rear wall surface.

5. The shaft seal assembly of claim 3, wherein the front wall surface and / or the rear wall surface is a high-gloss surface, the friction coefficient of which is smaller than the friction coefficient of the fixed seat outer surface.

6. The shaft seal assembly of claim 2, wherein the front wall surface and / or the rear wall surface is a high-gloss surface, the friction coefficient of which is smaller than the friction coefficient of the fixed seat outer surface.

7. The shaft seal assembly of claim 1, wherein the front wall surface and / or the rear wall surface is a high-gloss surface, the friction coefficient of which is smaller than the friction coefficient of the fixed seat outer surface.

8. The axial seal assembly of claim 1 , wherein the movable seals are axially pre-fitted into the front and rear wall surfaces, respectively.

9. The axial seal assembly of a hand-held instrument as described in claim 8, characterized in that the movable seal assembly further includes an annular locking clip, the annular locking clip being fitted onto an outer peripheral surface of the movable seal material, and the annular locking clip and the movable seal material are fitted together in a radially press-fit manner.

10. The shaft seal assembly of a hand-held instrument according to claim 9, characterized in that the outer peripheral surface of the movable seal member is provided with an annular stopper groove, and the annular locking clip is provided in the stopper groove.

11. The axial seal assembly of a hand-held instrument according to claim 10, characterized in that the annular locking clip is a coil spring, and the front and rear ends of the annular locking clip elastically abut against both axially opposing side wall surfaces of the stopper groove, respectively.

12. The axial seal assembly of claim 9, wherein the axial interference between the movable seal and the fixed seat is [0.1%, 0.5%].

13. The axial seal assembly of claim 8, wherein the axial interference between the movable seal and the fixed seat is [0.1%, 0.5%].

14. 2. The shaft seal assembly of claim 1, wherein the fixed seat includes a base and a front cover fixedly connected to the base, the base and the front cover surroundingly form the bushing through hole and the seal groove, the bushing through hole includes a rear opening opened in the base and a front opening opened in the front cover, a front wall surface of the seal groove is formed in the front cover, and a rear wall surface of the seal groove is formed in the base.

15. 15. The shaft seal assembly of a hand-held instrument according to claim 14, characterized in that the base includes a sealing tube, the inner peripheral surface of the sealing groove is formed in the sealing tube, an annular groove is provided on the inner wall surface of the front end of the sealing tube, the front cover includes a cover plate and an inner stopper, the cover plate is placed over the front open mouth of the sealing tube, the inner stopper is annular and protrudes from the rear side of the cover plate, and the inner stopper is fitted into the annular groove.

16. The axial seal assembly of a hand-held instrument according to claim 12, characterized in that the movable sealing material is made of rubber or silica gel material, the base and the front cover are both made of plastic material, and the rear end surface of the inner stopper is fixed to the inner wall surface of the annular groove by ultrasonic welding.

17. The axial seal assembly of a hand-held instrument as described in claim 16, characterized in that an outer peripheral surface of the inner stopper hole is provided with an outer stopper plane, and an inner peripheral surface of the annular groove is provided with an inner stopper plane that is fitted and bonded to the outer stopper plane.

18. The axial seal assembly of a hand-held instrument as described in claim 15, characterized in that an outer peripheral surface of the inner stopper hole is provided with an outer stopper plane, and an inner peripheral surface of the annular groove is provided with an inner stopper plane that is fitted and bonded to the outer stopper plane.

19. The axial seal assembly of a hand-held instrument according to claim 15, characterized in that the base further includes a positioning protrusion provided on a front end surface of the seal tube, and an outer edge of the front cover is provided with a positioning groove that fits the positioning protrusion.

20. The axial seal assembly of a hand-held instrument as described in claim 19, characterized in that the positioning protrusion extends along the axial direction and protrudes from the outer peripheral surface of the seal tube, and an insertion groove that fits the positioning protrusion is provided on the inner wall surface of the static seal material.

21. 1. A front end waterproof assembly for a handheld instrument, comprising: a case having an accommodating cavity formed therein and a seal through hole communicating with the accommodating cavity provided on a front end surface of the case; a stationary seal member provided in the seal through hole, sealingly fitted to the seal through hole, and having a movable shaft hole communicating with the accommodating cavity; and the shaft seal assembly of claim 1, wherein: A central shaft is drilled into the movable shaft hole and extends outward from the case, the central shaft is sealed and rotatably fitted into the movable shaft hole, A front end waterproof assembly for a hand-held instrument, characterized in that the movable seal assembly is provided in the receiving cavity and is located behind the stationary seal, and the fixed seat is fixedly installed relative to the case.

22. The front end waterproof assembly of a hand-held instrument as described in claim 21, characterized in that the static seal material has an annular seal surface facing rearward, the annular seal surface is formed around the movable shaft hole, and the front side of the fixed seat is bonded and sealed to the annular seal surface.

23. 23. The front end waterproof assembly of claim 22, wherein the fixed seat and the stationary seal have an axial interference fit.

24. The front end waterproof assembly of a hand-held instrument according to claim 22, characterized in that the outer peripheral surface of the fixed seat is provided with a positioning protrusion extending along the axial direction, and the inner wall surface of the static seal material is provided with an insertion groove that fits the positioning protrusion.

25. The front end waterproof assembly of a hand-held instrument according to claim 21, characterized in that the outer peripheral surface of the fixed seat is provided with a positioning protrusion extending along the axial direction, and the inner wall surface of the static seal material is provided with an insertion groove that fits the positioning protrusion.

26. 1. A front end waterproof assembly for a handheld instrument, comprising: a case having an accommodating cavity formed therein and a seal through hole communicating with the accommodating cavity provided on a front end surface of the case; a stationary seal member provided in the seal through hole, sealingly fitted to the seal through hole, and having a movable shaft hole communicating with the accommodating cavity; and the handheld instrument shaft seal assembly of claim 2, wherein: A central shaft is drilled into the movable shaft hole and extends outward from the case, the central shaft is sealed and rotatably fitted into the movable shaft hole, A front end waterproof assembly for a hand-held instrument, characterized in that the movable seal assembly is provided in the receiving cavity and is located behind the stationary seal, and the fixed seat is fixedly installed relative to the case.

27. The front-end waterproof assembly of a hand-held instrument according to claim 26, characterized in that the outer peripheral surface of the fixed seat is provided with a positioning protrusion extending along the axial direction, and the inner wall surface of the static seal material is provided with an insertion groove that fits the positioning protrusion.

28. A handheld device body including a handle and a motor, The hand-held instrument body further includes a shaft seal assembly of the hand-held instrument according to claim 1, wherein the central shaft is a part of the rotor of the motor, and the fixed seat is fixedly installed relative to the handle; or The handheld device body further includes a front end waterproof assembly of the handheld device described in claim 21, wherein the handle is the case, the motor is provided in a housing cavity of the case, and the central shaft is part of the rotor of the motor.

29. A handheld device body including a handle and a motor, The hand-held instrument body further includes a shaft seal assembly of the hand-held instrument according to claim 2, wherein the central shaft is a part of the rotor of the motor, and the fixed seat is fixedly installed relative to the handle; or The handheld device body further includes a front end waterproof assembly of the handheld device described in claim 22, characterized in that the handle is the case, the motor is provided in a housing cavity of the case, and the central shaft is part of the rotor of the motor.

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