Vibrating toothbrush and eccentric shaft

Abstract

A vibrating toothbrush and an eccentric shaft according to an embodiment of the present application have a head portion in which a brush head is implanted and a handle portion in which a head coupling portion for coupling and uncoupling the head portion is protrusively formed. The vibrating toothbrush is characterized by including an electric motor accommodated in the handle portion for generating a rotational force and an eccentric shaft connected to the electric motor for rotation and eccentricity and vibration generation to thereby transmit the vibration to the head coupling portion. The eccentric shaft includes a motor fixing portion connected to the electric motor, an eccentric hammer offset from a rotational center of the electric motor, and a rotational shaft of a metal material for connecting the motor fixing portion and the eccentric hammer.

Description

[0001] This application is a divisional application of the invention patent application filed on April 25, 2018, with national application number 201880087925.0 (international application number PCT / KR2018 / 004805) and invention title "vibrating toothbrush and eccentric shaft". Technical Field

[0002] This invention relates to a vibrating toothbrush and an eccentric shaft, which can be securely manufactured to produce vibrations. Background Technology

[0003] Generally, toothbrushes are made of plastic and consist of a head with bristles and a handle extending from the head for the user to hold. The user uses the toothbrush by gripping the handle, and the bristles in the head stimulate the tooth surface, interdental spaces, and gums to remove debris or plaque.

[0004] To maximize the effectiveness of brushing, it is recommended to brush for about 2 to 3 minutes. However, this recommended brushing time may put pressure on the wrists, cause arm fatigue, and make it difficult to adjust the force of head movements, which may sometimes result in scraping of the gums or inside the mouth.

[0005] To eliminate these drawbacks and improve user convenience, toothbrush products have been developed that use an electric motor to rotate after receiving power from a dry cell battery or a storage battery, thereby rotating the brush head bristles, or converting the rotational force from the electric motor into vibration or generating ultrasonic vibration. Such products are more effective in removing foreign objects from teeth or the oral cavity through the rotation or vibration of the brush head bristles.

[0006] In the products currently under development, those that use an electric motor to generate vibrations transmit the vibrations generated when the eccentric shaft rotates to the head via an eccentric shaft connected to the electric motor.

[0007] However, current eccentric shafts are made of synthetic resins such as plastics, which leads to breakage under strong rotation. Alternatively, if the thickness is increased to prevent breakage, elasticity cannot be guaranteed, resulting in inadequate vibration transmission and increased noise. Insufficient elasticity can cause the eccentric shaft to stop rotating abruptly due to external impact, a serious problem.

[0008] As mentioned above, current vibrating toothbrushes have limitations in terms of materials or shape, making it difficult to simultaneously ensure durability and elasticity. With the increasing demand for vibrating toothbrushes from consumers, there is an urgent need to develop technologies to address these issues.

[0009] Existing technical documents

[0010] Existing document 1: Korean Patent Registration No. 10-0886164 (registered on February 23, 2009) Summary of the Invention

[0011] Technical issues

[0012] This invention is made to improve the prior art. The purpose of this invention is to provide a vibrating toothbrush and an eccentric shaft, using at least a portion of the eccentric shaft made of metal, thereby ensuring durability while ensuring elasticity and resilience.

[0013] Problem-solving methods

[0014] A vibrating toothbrush according to an embodiment of the present invention has a head and a handle. The head is incorporating brush bristles, and the handle protrudes to form a head-joining portion for attaching and detaching the head. The vibrating toothbrush is characterized by comprising: an electric motor housed within the handle for generating rotational force; and an eccentric shaft connected to the electric motor for rotation, at least a portion of which is eccentric and generates vibration, thereby transmitting vibration to the head-joining portion. The eccentric shaft comprises: a motor fixing portion connected to the electric motor; an eccentric hammer offset from the rotation center of the electric motor; and a metal rotating shaft for connecting the motor fixing portion and the eccentric hammer.

[0015] Specifically, the aforementioned rotating shaft can have a diameter of 0.4 to 1.0 mm.

[0016] Specifically, the distance by which the centerline of the aforementioned eccentric hammer is offset from the rotation center of the aforementioned electric motor can be within 2.0 mm.

[0017] Specifically, the eccentric shaft may further include a hammer fixing part, which connects the eccentric hammer and the rotating shaft. The motor fixing part and the hammer fixing part may have a relatively larger cross-section than the rotating shaft.

[0018] Specifically, the eccentric shaft may further include an impact absorbing part, which is disposed between the motor fixing part and the rotating shaft or between the hammer fixing part and the rotating shaft.

[0019] Specifically, the impact-absorbing portion may have a shape in which the cross-section gradually increases as it moves closer to the motor fixing portion or the hammer fixing portion from the rotating shaft.

[0020] Specifically, the aforementioned impact-absorbing part may have at least one groove on its surface.

[0021] Specifically, the groove gradually increases in size as it moves closer to the motor mounting portion or the hammer mounting portion from the rotating shaft.

[0022] Specifically, the impact-absorbing part may have a height of up to 35% of the length between the motor fixing part and the hammer fixing part.

[0023] Specifically, the impact-absorbing portion disposed between the motor fixing portion and the rotating shaft may have a relatively smaller height than the impact-absorbing portion disposed between the rotating shaft and the hammer fixing portion.

[0024] Specifically, the aforementioned rotating shaft can be indirectly connected to the aforementioned motor fixing part or the aforementioned hammer fixing part via the aforementioned impact absorption part.

[0025] Specifically, the impact-absorbing part can be configured to surround one end of the rotating shaft and be directly connected to the motor fixing part or the hammer fixing part, or the other end.

[0026] Specifically, the portion of the eccentric shaft other than the rotating shaft is made of synthetic resin. The hammer fixing part and the eccentric hammer are integrally formed. One end of the rotating shaft is connected to the hammer fixing part, and the other end is connected to the motor fixing part, thereby connecting the motor fixing part and the eccentric hammer.

[0027] Specifically, the eccentric hammer can be disposed adjacent to or within the head joint.

[0028] Specifically, the aforementioned eccentric shaft may further include a bearing fixing part, which protrudes from the aforementioned eccentric hammer and is rotatably coupled to a bearing disposed within the aforementioned head coupling part.

[0029] Specifically, the bearing fixing part may have a cross-section that is relatively larger than that of the rotating shaft and a cross-section that is relatively smaller than that of the motor fixing part or the hammer fixing part.

[0030] According to an embodiment of the present invention, the eccentric shaft is used in a vibrating toothbrush that incorporates an electric motor and provides vibration to the brush head bristles. The eccentric shaft is characterized by comprising: a motor fixing part connected to the electric motor; an eccentric hammer offset from the rotation center of the electric motor; and a metal rotating shaft for connecting the motor fixing part and the eccentric hammer.

[0031] Specifically, it may also include: a hammer fixing part for connecting the eccentric hammer and the rotating shaft; and an impact absorbing part disposed between the motor fixing part and the rotating shaft or between the hammer fixing part and the rotating shaft, and having at least one groove on its surface.

[0032] Invention Effects

[0033] The vibrating toothbrush and eccentric shaft of the present invention, by utilizing a metal material such as nickel-titanium to form a part of the eccentric shaft, can ensure elasticity and tension, and minimize the thickness of the metal part of the eccentric shaft, while limiting the distance between the center line of the eccentric hammer and the rotation center of the eccentric shaft, thereby efficiently suppressing noise generation. Attached Figure Description

[0034] Figure 1 This is an exploded view of a vibrating toothbrush according to an embodiment of the present invention.

[0035] Figure 2 This is a cross-sectional view of a vibrating toothbrush according to an embodiment of the present invention.

[0036] Figure 3 This is a perspective view of the eccentric shaft of a vibrating toothbrush according to an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures

[0038] 1: Vibrating toothbrush 10: Head

[0039] 11: Brush head bristles 20: Handle

[0040] 21: Head junction 211: Protrusion

[0041] 212: Bearing 22: Switch

[0042] 30: Power supply section 40: Electric motor

[0043] 41: Motor shaft; 50: Eccentric shaft

[0044] 51: Motor mounting part; 52: Eccentric hammer

[0045] 53: Rotating shaft 54: Hammer fixing part

[0046] 55a, 55b: Impact absorption section; 551: Groove

[0047] 56: Bearing fixing part Detailed Implementation

[0048] The objectives, specific advantages, and novel features of this invention will become clearer from the following detailed description in conjunction with the accompanying drawings and preferred embodiments. It should be noted that, in this specification, when labeling structural elements in the various drawings, the same reference numerals are used as much as possible for the same structural elements, even if they are shown in different drawings. Furthermore, when describing this invention, detailed descriptions of related well-known technologies are omitted if it is determined that such descriptions may obscure the spirit of the invention.

[0049] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0050] For reference, in the following description, one end can be the direction in which the head is set based on the vibrating toothbrush, and the other end is the direction in which the cap is set, but it is not limited to this.

[0051] Figure 1 This is an exploded view of a vibrating toothbrush according to an embodiment of the present invention. Figure 2 This is a cross-sectional view of a vibrating toothbrush according to an embodiment of the present invention. Figure 3 This is a perspective view of the eccentric shaft of a vibrating toothbrush according to an embodiment of the present invention.

[0052] Reference Figures 1 to 3 According to an embodiment of the present invention, a vibrating toothbrush 1 includes a head 10, a handle 20, a power supply 30, an electric motor 40, and an eccentric shaft 50.

[0053] The head 10 is fitted with brush bristles 11. The head 10 is inserted into the head joint 21 of the handle 20 (described later), and the vibration transmitted from the head joint 21 can be transmitted to the teeth through the brush bristles 11.

[0054] The brush bristles 11 can be disposed on one side of the head 10, but can also be disposed on the back side, including one side. That is, the position of the brush bristles 11 is not particularly limited. Furthermore, when one side of the head 10 has a plurality of bristle holes (not shown in the accompanying drawings), the brush bristles 11 can be configured such that a plurality of brushes are fixed in each bristle hole, or can be configured such that a single brush made of synthetic resin is inserted and fixed in one bristle hole.

[0055] Furthermore, the arrangement of the brush bristles 11 on one side of the head 10 is not particularly limited. That is, the number or size of the brush bristles 11 arranged horizontally and vertically can be set in various ways, and the size of the side in which the brush bristles 11 are implanted in the head 10 is not limited.

[0056] The bristles 11 of the head 10 can receive vibrations generated by the rotation of the eccentric shaft 50, which will be described later. Therefore, the user can brush their teeth by rubbing the bristles 11 of the head 10 against their teeth or between their teeth while holding the handle 20. In this case, compared with existing toothbrushes that do not vibrate, the head 10 makes it easier for foreign objects to be removed from the teeth or between their teeth by vibrating, thereby improving brushing efficiency.

[0057] The head 10 may be provided with a hole (not shown in the figure) into which the head coupling 21 can be inserted, so that the user can clamp the head 10 into the head coupling 21 to connect the head 10 to the handle 20.

[0058] When the bristles 11 implanted in the head 10 become old, the user can separate the head 10 from the head joint 21 and insert a new head 10 for use. Furthermore, different heads 10 with different arrangements of bristles 11 can be inserted alternately into the head joint 21 for use.

[0059] The handle portion 20 protrudes to form a head coupling portion 21 for attaching and detaching the head 10. One end of the handle portion 20 may protrude in a rod shape to form the head coupling portion 21, so that the user can connect the head 10 to the head coupling portion 21, thereby allowing the vibration generated from the handle portion 20 to be transmitted to the brush head bristles 11.

[0060] One end of the head joint 21 is formed as a free end for engaging with the head 10, and the other end may be provided with a shock-absorbing component (not shown) so as to prevent the vibration generated inside the handle 20 from returning to the part of the user gripping the handle 20 when it is transmitted to the head 10 through the head joint 21.

[0061] That is, the root end of the head joint 21 is surrounded by a shock-absorbing component, so that even if the head joint 21 is vibrated, the vibration will not return to the part of the user holding the handle 20 or the return vibration will be minimal.

[0062] At this time, the shock-absorbing component can be an elastic component such as a spring. However, in order to prevent water or other substances from entering the handle portion 20 through the root end of the head joint 21, a component such as rubber, which can also achieve a sealing function, can be used as the shock-absorbing component.

[0063] The head joint 21 may be provided with a protrusion 211. The head joint 21 may be rod-shaped, and the head 10 may be provided with a hole corresponding to the shape of the head joint 21, so that the head 10 can be clamped into the head joint 21. In this case, the protrusion 211 may be used to define the engagement direction of the head 10.

[0064] Of course, if the cross-section of the head joint 21 is not circular, the direction in which the head 10 is joined to the head joint 21 can be defined even without the protrusion 211. Therefore, the protrusion 211 can be omitted in this case.

[0065] The handle 20 is internally equipped with a power supply unit 30, an electric motor 40, an eccentric shaft 50, etc. At this time, at least a portion of the eccentric shaft 50 can be located inside the head joint 21. In particular, the eccentric hammer 52 included in the eccentric shaft 50 can be located inside the head joint 21. Therefore, when vibration is generated by the eccentric hammer 52, the vibration can be transmitted to the head 10 through the head joint 21 with high efficiency.

[0066] At this time, a bearing 212 may be provided on one end of the inner side of the head joint 21. The bearing 212 is configured to rotatably support one end of the eccentric shaft 50 so that the eccentric shaft 50 provided in the head joint 21 can rotate stably, and the bearing fixing part 56 of the eccentric shaft 50, which will be described later, may be connected to the bearing 212.

[0067] A cover (not shown in the attached drawings) may be provided on the opposite side of the end where the head joint 21 is provided on the handle part 20. The cover may be configured to open or close the interior of the handle part 20, and the power supply part 30 and the like housed inside the handle part 20 may be replaced by the cover.

[0068] Furthermore, the cover can be configured to supply power to the power supply unit 30. For example, the cover may have a structure that allows it to receive power from the outside and then transfer it to the power supply unit 30. In this case, the cover structure does not need to be metal; it can have a widely used structure for contactless charging.

[0069] The handle 20 is equipped with a switch 22. The switch 22 controls the vibration to be turned on / off and can be connected to the electric motor 40. If the user presses the switch 22 while holding the handle 20, the electric motor 40 is started, the eccentric shaft 50 rotates, the eccentric hammer 52 vibrates, and the brush head bristles 11 are vibrated.

[0070] In this case, switch 22 can be configured to control only on / off states, or it can be configured to control vibration modes. That is, in this embodiment, two or more vibration modes can be stored, and the vibration mode can be switched whenever switch 22 is pressed repeatedly. Here, vibration mode refers to the vibration period, intensity, duration, etc.

[0071] Of course, multiple switches 22 can be provided, one of which can be used to control the on / off state, and another switch 22 can be used to select the vibration mode. Furthermore, LEDs or other lighting (not shown) can be attached near the switches 22 or at a predetermined position on the handle 20. The lighting can indicate whether the vibration is on / off or the vibration mode, the status of the power supply 30, etc.

[0072] The power supply unit 30 is housed within the handle portion 20 and supplies power to the electric motor 40. The power supply unit 30 can be a replaceable battery type, in which case the cover of the handle portion 20 can be opened to replace the power supply unit 30.

[0073] Alternatively, the power supply unit 30 may be a non-replaceable battery that can be charged using the cover of the handle 20. Of course, the power supply unit 30 may also be configured to be both replaceable and rechargeable while housed within the handle 20.

[0074] The power storage capacity of the power supply unit 30 can be displayed to the user through the lighting described above. Alternatively, when it is determined that the power supply unit 30 is low, it can provide vibration in a different vibration mode than that used for brushing teeth, so that the user can be aware of this.

[0075] The power supply unit 30 can maintain an electrical connection with the electric motor 40, and its power supply can be controlled by the switch 22. The power supply unit 30 is located inside the handle 20, close to the electric motor 40.

[0076] The electric motor 40 is housed within the handle portion 20 and generates rotational force. The electric motor 40 can be started after receiving power from the power supply portion 30, and its start-up status and rotation state can be adjusted via the switch 22.

[0077] The electric motor 40 is provided with a motor shaft 41, and the other end of the eccentric shaft 50 is connected to the motor shaft 41. That is, one end of the eccentric shaft 50 is rotatably connected to the bearing 212 provided in the head joint 21, and the other end can be connected to the motor shaft 41 so as to rotate together with the motor shaft 41.

[0078] In this embodiment, the rotating shaft 53 of the eccentric shaft 50 is made of metal. Therefore, in order to ensure the durability and elasticity of the eccentric shaft 50 while ensuring vibration force, the length of the rotating shaft 53 can be sufficiently extended. In this case, the size of the electric motor 40 can be miniaturized. That is, in this embodiment, the electric motor 40 can be reduced in size by more than 50% compared with the motors currently used. Even in this case, since the rotating shaft 53 of this embodiment is made of metals such as nickel-titanium, vibration transmission efficiency can still be ensured by fully ensuring the total length of the eccentric shaft 50.

[0079] An eccentric shaft 50 is connected to and rotates an electric motor 40, at least partially eccentric, and generates vibration, thereby transmitting the vibration to the head joint 21. The vibration generated by the eccentric shaft 50 is transmitted to the head 10 via the head joint 21. However, as described above, a shock-absorbing component is provided at the other end of the head joint 21, so the vibration generated by the eccentric shaft 50 can be suppressed from being transmitted to the user's hand.

[0080] The eccentric shaft 50 includes a motor fixing part 51, an eccentric hammer 52, a rotating shaft 53, a hammer fixing part 54, impact absorbing parts 55a and 55b, and a bearing fixing part 56.

[0081] The motor mounting part 51 is connected to the electric motor 40. The motor mounting part 51 is a structure that surrounds the motor shaft 41 of the electric motor 40 and is firmly attached to the motor shaft 41, so that when the motor shaft 41 rotates, the eccentric shaft 50 can rotate together as a whole.

[0082] The motor mounting part 51 surrounds the motor shaft 41, and in order to avoid free rotation with the motor shaft 41 as a reference, the motor shaft 41 or the hole of the motor mounting part 51 for inserting the motor shaft 41 may have a non-circular cross section.

[0083] Alternatively, the motor shaft 41 may be provided with a protrusion (not shown) similar to that described above, so that when the motor shaft 41 is clamped in the motor fixing part 51, the motor shaft 41 and the motor fixing part 51 rotate as a whole.

[0084] The eccentric hammer 52 can be disposed adjacent to or within the head joint 21, offset from the rotation center of the electric motor 40. When the eccentric shaft 50 rotates, it rotates with its center line offset from the rotation center of the eccentric shaft 50, thus generating vibration. In this case, the center line of the eccentric hammer 52 can be represented as a line passing through the center of weight in the length direction.

[0085] The centerline of the eccentric hammer 52 can be offset from the rotation center of the electric motor 40 by, for example, within 2.0 mm. This is because if the centerline of the eccentric hammer 52 deviates too far from the rotation center of the electric motor 40, the vibration generated by the eccentric shaft 50 will increase, potentially causing discomfort to the user. Furthermore, as the eccentric shaft 50 rotates, the eccentric hammer 52 gradually tilts away from the rotation center of the eccentric shaft 50, thereby striking the inner surface of the head joint 21 and potentially generating noise. Of course, the distance between the centerline of the eccentric hammer 52 and the rotation center of the electric motor 40 is not limited to the above range.

[0086] In particular, in this embodiment, even when an external pressure of 1.0 kgf is applied, noise generated by the eccentric hammer 52 of the rotating eccentric shaft 50 can be suppressed. At this time, although there is external pressure or impact, the generation of noise can be suppressed by the gap between the center line of the eccentric hammer 52 and the rotation center of the electric motor 40, the material of the rotating shaft 53, and / or the impact absorption parts 55a, 55b, etc.

[0087] The rotating shaft 53 connects the motor fixing part 51 and the eccentric hammer 52. One end of the rotating shaft 53 can be connected to the eccentric hammer 52 and the other end can be connected to the motor fixing part 51. However, one end of the rotating shaft 53 can be connected to the eccentric hammer 52 through the hammer fixing part 54.

[0088] The rotating shaft 53 connects the motor mounting part 51 and the eccentric hammer 52, and can be made of metal. In this case, the rotating shaft 53 is made of nickel-titanium or the like, as nickel-titanium is the material that best ensures the elasticity, restoring force, and durability used to achieve the basic functions of the eccentric shaft 50.

[0089] That is, for the rotating shaft 53 made of nickel-titanium instead of synthetic resin, even if an external impact is applied, the elasticity and restoring force can effectively suppress the noise generated by the collision between the eccentric hammer 52 and the inner surface of the head joint 21, while ensuring durability and preventing breakage.

[0090] However, to improve the restoring force and elasticity, the rotating shaft 53 can have a diameter of 0.4 to 1.0 mm, preferably 0.7 to 0.8 mm. A rotating shaft 53 with such a diameter can eliminate the problem of increased vibration amplitude of the eccentric hammer 52 when the diameter is very small, thus preventing conflict between the eccentric hammer 52 and the head joint 21, while also eliminating the problem of reduced restoring force when the diameter is very large.

[0091] That is, according to this embodiment, the rotating shaft 53 is made of metals such as nickel-titanium, so that when the eccentric shaft 50 rotates, the rotating shaft 53 ensures the restoring force and elasticity, thereby suppressing the noise caused by the eccentric hammer 52, while ensuring durability, thereby preventing the eccentric shaft 50 from breaking.

[0092] The hammer fixing part 54 connects the eccentric hammer 52 and the rotating shaft 53. If the eccentric hammer 52 is directly connected to the rotating shaft 53, the connection between the rotating shaft 53 and the eccentric hammer 52 may become weak due to stress concentration because of the height difference that may occur between the rotating shaft 53 and the eccentric hammer 52. By providing the hammer fixing part 54 between the rotating shaft 53 and the eccentric hammer 52, the weak part can be secured.

[0093] At this time, similar to the motor fixing part 51, the hammer fixing part 54 can have a relatively larger cross-section than the rotating shaft 53. The diameters of the hammer fixing part 54 and the motor fixing part 51 can be the same or different. However, as an example, since the hammer fixing part 54 is a configuration connecting the rotating shaft 53 and the eccentric hammer 52, it can have a diameter larger than the diameter of the rotating shaft 53 and smaller than the maximum diameter of the eccentric hammer 52. That is, when the diameter of the motor fixing part 51 is the same as the maximum diameter of the eccentric hammer 52, the diameter of the hammer fixing part 54 can be smaller than the diameter of the motor fixing part 51.

[0094] Impact-absorbing portions 55a and 55b are disposed between the motor fixing portion 51 and the rotating shaft 53 and / or between the hammer fixing portion 54 and the rotating shaft 53. The impact-absorbing portions 55a and 55b may have a shape in which the cross-section gradually increases as it moves closer to the motor fixing portion 51 or the hammer fixing portion 54 from the rotating shaft 53. For example, they may have a shape such as a truncated cone.

[0095] As explained in the hammer fixing part 54 above, the impact absorbing parts 55a and 55b are provided to prevent the part of the eccentric shaft 50 whose cross-section suddenly expands from becoming fragile.

[0096] At this point, the impact-absorbing parts 55a and 55b can have a height of up to 35% of the length between the motor fixing part 51 and the hammer fixing part 54, which is the optimal value to ensure elasticity and recovery force.

[0097] The impact-absorbing portion 55a disposed between the motor mounting portion 51 and the rotating shaft 53 may have a relatively smaller height compared to the impact-absorbing portion 55b disposed between the rotating shaft 53 and the hammer mounting portion 54. Furthermore, the impact-absorbing portion 55a disposed between the motor mounting portion 51 and the rotating shaft 53 may have the same or different maximum cross-section as the impact-absorbing portion 55b disposed between the rotating shaft 53 and the hammer mounting portion 54. Of course, the sizes of the two impact-absorbing portions 55a and 55b are not limited to the above descriptions.

[0098] The impact absorption parts 55a and 55b can be used to indirectly connect the rotating shaft 53 to the motor fixing part 51 and the hammer fixing part 54. That is, the rotating shaft 53 can be fixed only to the impact absorption parts 55a and 55b, and is not directly connected to the motor fixing part 51 and the hammer fixing part 54.

[0099] Of course, the impact absorption parts 55a and 55b can be configured to surround one end of the rotating shaft 53 that is directly connected to the hammer fixing part 54 or the motor fixing part 51. That is, one end or the other end of the rotating shaft 53 can be directly or indirectly connected to the hammer fixing part 54 or the motor fixing part 51, and the impact absorption parts 55a and 55b can be configured to surround the connecting part.

[0100] The impact-absorbing portions 55a and 55b may be provided with grooves 551. In this embodiment, forming at least one groove 551 on the surface increases elasticity and absorbs impact. The groove 551 may have a shape that gradually increases in size as it moves closer to the motor fixing portion 51 or the hammer fixing portion 54 from the rotating shaft 53, but the shape, size, or arrangement of the groove 551 is not limited to the above.

[0101] The bearing fixing part 56 protrudes from the eccentric hammer 52 and is rotatably coupled to the bearing 212 provided in the head coupling part 21. Unlike the motor fixing part 51, which surrounds the motor shaft 41 and rotates integrally with the motor shaft 41, the bearing fixing part 56 is fixed to the bearing 212 and is configured to rotate separately from the head coupling part 21.

[0102] That is, when the eccentric shaft 50 rotates via the electric motor 40, the bearing fixing part 56 at one end of the eccentric shaft 50 is supported by the bearing 212, so the eccentric shaft 50 can rotate stably and continuously. At this time, the bearing fixing part 56 has a relatively larger cross-section than the rotating shaft 53, but it can have a relatively smaller cross-section than the motor fixing part 51 or the hammer fixing part 54.

[0103] In addition to the rotating shaft 53, which is made of metal, the eccentric shaft 50 can be made of non-metallic material (for example, synthetic resin). In this case, the hammer fixing part 54, the eccentric hammer 52, and the bearing fixing part 56 can be integrally formed, and the motor fixing part 51 can be provided separately.

[0104] Therefore, one end of the rotating shaft 53 is directly or indirectly connected to the hammer fixing part 54, and the other end is directly or indirectly connected to the motor fixing part 51, thereby connecting the motor fixing part 51 and the eccentric hammer 52. That is, the eccentric shaft 50 can be manufactured in the following manner: after preparing a component consisting of the rotating shaft 53, the motor fixing part 51, the hammer fixing part 54, the eccentric hammer 52, and the bearing fixing part 56, the motor fixing part 51 and the above-mentioned components are connected across the rotating shaft 53.

[0105] Of course, if the hammer fixing part 54 and the like are all made of metal, the eccentric shaft 50 can be manufactured as a single piece. However, in this case, the vibration may be aggravated and the recovery force may be reduced. Therefore, in this embodiment, only the rotating shaft 53 is made of metal, and the other components constituting the eccentric shaft 50 are made of synthetic resin or the like. The eccentric shaft 50 can be completed through an assembly process.

[0106] As described above, in this embodiment, the rotating shaft 53 in the eccentric shaft 50 is made of metal, thereby ensuring durability while ensuring elasticity and resilience. This can suppress noise generation, extend service life, and maximize consumer satisfaction.

[0107] The present invention is not limited to the above embodiments, and may also include combinations of the above embodiments or combinations of one of the above embodiments and common general knowledge as another embodiment.

[0108] The present invention has been described in detail above through specific embodiments. However, these are only for illustrating the present invention, and the present invention is not limited thereto. It should be understood that those skilled in the art can modify or improve it within the technical concept of the present invention.

[0109] Simple variations and modifications of the present invention are all included within the scope of the present invention, and the specific scope of protection of the present invention is defined in accordance with the appended claims.

Claims

1. A vibrating toothbrush having a head and a handle, wherein the head is incorporating brush bristles, and the handle protrudes to form a head-jointing portion for attaching and detaching the head, the vibrating toothbrush being characterized in that it comprises: An electric motor, housed within the aforementioned handle, is used to generate rotational force; as well as An eccentric shaft, connected to the aforementioned electric motor, rotates, with at least a portion eccentric and generating vibration, thereby transmitting the vibration to the aforementioned head joint. The aforementioned eccentric shaft includes: A motor mounting part is connected to the aforementioned electric motor; The eccentric hammer is offset from the rotation center of the aforementioned electric motor; A rotating shaft, used to connect the aforementioned motor mounting part and the aforementioned eccentric hammer, is made of metal and possesses elasticity and restoring force; and The hammer fixing part connects the eccentric hammer and the rotating shaft. The aforementioned rotating shaft is provided with impact-absorbing parts on both sides to absorb external impacts. The aforementioned rotating shaft has a relatively small cross-section compared to the aforementioned motor fixing part, the aforementioned eccentric hammer, and the aforementioned hammer fixing part. The aforementioned rotating shaft is formed separately from the aforementioned impact-absorbing part, the aforementioned hammer fixing part, and the aforementioned motor fixing part. The aforementioned impact-absorbing portion surrounds the area around one end of the aforementioned rotating shaft that is directly connected to the aforementioned motor fixing portion and the aforementioned hammer fixing portion, and the other end thereof. The aforementioned impact-absorbing sections are symmetrically arranged on the left and right sides of the aforementioned rotation axis and have the same maximum cross-section. The aforementioned impact-absorbing portion includes a first end and a second end, the first end covering the aforementioned rotating shaft, and the second end adjacent to the aforementioned motor fixing portion or the aforementioned hammer fixing portion. The impact-absorbing portion has a shape in which the cross-section gradually expands as it gets closer to the motor fixing portion or the hammer fixing portion from the rotating shaft, thereby having a first cross-sectional area at the first end and a second cross-sectional area at the second end that is larger than the first cross-sectional area.

2. The vibrating toothbrush according to claim 1, characterized in that, The aforementioned rotating shaft has a diameter of 0.4 to 1.0 mm.

3. The vibrating toothbrush according to claim 1, characterized in that, The centerline of the aforementioned eccentric hammer is offset from the rotation center of the aforementioned electric motor by a distance of less than 2mm.

4. The vibrating toothbrush according to claim 1, characterized in that, One of the impact-absorbing parts is connected between the motor fixing part and the rotating shaft, and the other impact-absorbing part is connected between the hammer fixing part and the rotating shaft.

5. The vibrating toothbrush according to claim 4, characterized in that, The aforementioned rotating shaft is not directly connected to the aforementioned eccentric hammer, but is indirectly connected to the aforementioned eccentric hammer through the aforementioned other impact absorption part and the aforementioned hammer fixing part.

6. The vibrating toothbrush according to claim 1, characterized in that, The aforementioned motor mounting part is connected to the motor shaft of the aforementioned electric motor. The aforementioned rotating shaft is thinner than the aforementioned motor shaft.

7. The vibrating toothbrush according to claim 1, characterized in that, The aforementioned impact-absorbing part has a height of no more than 35% of the length between the aforementioned motor fixing part and the aforementioned hammer fixing part.

8. The vibrating toothbrush according to claim 1, characterized in that, The aforementioned rotating shaft is indirectly connected to the aforementioned motor fixing part or the aforementioned hammer fixing part via the aforementioned impact absorbing part.

9. The vibrating toothbrush according to claim 1, characterized in that, The parts of the aforementioned eccentric shaft, excluding the rotating shaft, are made of synthetic resin. The aforementioned hammer fixing part and the aforementioned eccentric hammer are integrally formed. One end of the aforementioned rotating shaft is connected to the aforementioned hammer fixing part, and the other end is connected to the aforementioned motor fixing part, thereby connecting the aforementioned motor fixing part and the aforementioned eccentric hammer.

10. The vibrating toothbrush according to claim 1, characterized in that, The aforementioned eccentric hammer is disposed adjacent to or within the aforementioned head joint portion.

11. The vibrating toothbrush according to claim 1, characterized in that, The aforementioned eccentric shaft also includes a bearing fixing part, which protrudes from the aforementioned eccentric hammer and is rotatably coupled to a bearing disposed within the aforementioned head coupling part.

12. The vibrating toothbrush according to claim 11, characterized in that, The bearing fixing part has a cross-section that is relatively larger than that of the rotating shaft and a cross-section that is relatively smaller than that of the motor fixing part or the hammer fixing part.

13. An eccentric shaft for use in a vibrating toothbrush with a built-in electric motor that provides vibration to the brush head bristles, the eccentric shaft being characterized by comprising: A motor mounting part is connected to the aforementioned electric motor; The eccentric hammer is offset from the rotation center of the aforementioned electric motor; A rotating shaft, used to connect the aforementioned motor mounting part and the aforementioned eccentric hammer, is made of metal and possesses elasticity and restoring force; and The hammer fixing part connects the eccentric hammer and the rotating shaft. The aforementioned rotating shaft is provided with impact-absorbing parts on both sides to absorb external impacts. The aforementioned rotating shaft has a relatively small cross-section compared to the aforementioned motor fixing part, the aforementioned eccentric hammer, and the aforementioned hammer fixing part. The aforementioned rotating shaft is formed separately from the aforementioned impact-absorbing part, the aforementioned hammer fixing part, and the aforementioned motor fixing part. The aforementioned impact-absorbing portion surrounds the area around one end of the aforementioned rotating shaft that is directly connected to the aforementioned motor fixing portion and the aforementioned hammer fixing portion, and the other end thereof. The aforementioned impact-absorbing sections are symmetrically arranged on the left and right sides of the aforementioned rotation axis and have the same maximum cross-section. The aforementioned impact-absorbing portion includes a first end and a second end, the first end covering the aforementioned rotating shaft, and the second end adjacent to the aforementioned motor fixing portion or the aforementioned hammer fixing portion. The impact-absorbing portion has a shape in which the cross-section gradually expands as it gets closer to the motor fixing portion or the hammer fixing portion from the rotating shaft, thereby having a first cross-sectional area at the first end and a second cross-sectional area at the second end that is larger than the first cross-sectional area.

14. The eccentric shaft according to claim 13, characterized in that, One of the aforementioned impact-absorbing parts is disposed between the motor fixing part and the rotating shaft, and the other impact-absorbing part is disposed between the hammer fixing part and the rotating shaft.

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