Dental handpiece handpiece and dental handpiece

Abstract

The application provides a dental handpiece head, which comprises a driving needle and a clamping needle assembly, and the clamping needle assembly is internally provided with a mounting cavity for mounting the driving needle; the inside or / and outside of the mounting cavity is provided with a sealing element, wherein the sealing element is used for cutting off the communication between the external space of the head and the tail part of the mounting cavity. The clamping needle assembly and the driving needle of the dental handpiece are sealed, so that physiological saline, blood and the like cannot enter the inside of the head during work, the head can always maintain good sealing performance, and the service life of the clamping needle assembly is prolonged. The application also provides a dental handpiece with the dental handpiece head.

Description

Technical Field

[0001] This invention belongs to the field of oral medical device technology, and specifically relates to a dental handpiece head and a dental handpiece. Background Technology

[0002] Dental handpieces are used inside the oral cavity and are constantly exposed to contaminants such as moisture, blood, and bacteria. After use, they require cleaning and disinfection, but are still susceptible to moisture and impurities. To protect critical components such as gears, springs, and bearings from contamination and corrosion, the handpiece head must be strictly sealed. While existing dental handpiece heads undergo sealing treatment, contamination and corrosion can still occur internally over prolonged use.

[0003] Therefore, ensuring that the machine head can always maintain good sealing performance is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a dental handpiece head and a dental handpiece that ensures the head can always maintain good sealing performance.

[0005] To solve the above technical problems, the present invention provides a dental handpiece head, including a bur and a bur clamping assembly, wherein the bur clamping assembly has a mounting cavity for mounting the bur.

[0006] A sealing element is provided inside and / or outside the mounting cavity, wherein the sealing element is used to isolate the external space from the tail end of the mounting cavity.

[0007] Optionally, in the dental handpiece head described above, a positioning structure is provided on the inner wall of the mounting cavity, wherein the positioning structure is used to position the seal.

[0008] Optionally, in the dental handpiece head described above, the positioning structure includes an annular positioning groove or a positioning step.

[0009] Optionally, in the above-mentioned dental handpiece head, the needle clamping assembly includes a retaining ring, the retaining ring is sleeved on the front end of the needle clamping assembly, the bur passes through the retaining ring and the needle clamping assembly is placed inside the retaining ring, and the sealing element is disposed in the cavity formed by the retaining ring, the needle clamping assembly and the bur, so as to achieve the sealing of the front end of the handpiece head.

[0010] Optionally, in the dental handpiece head described above, the sealing element is a first sealing ring.

[0011] Optionally, in the above-mentioned dental handpiece head, the retaining ring and the clamping pin assembly are an integral structure;

[0012] Alternatively, the retaining ring and the clamping pin assembly may be detachably connected.

[0013] Optionally, in the dental handpiece head described above, the outer wall of the rear end of the retaining ring is provided with a labyrinth-type sealing structure.

[0014] Optionally, the dental handpiece head described above may also include a bearing, a head housing, a nozzle, and a rear cover assembly; wherein,

[0015] The needle, the needle clamping assembly, the bearing, and the machine head housing are tightly fitted together sequentially from the inside out;

[0016] The machine head housing is a cylindrical structure with openings at both ends;

[0017] The nozzle is located at the front end of the machine head, and the rear cover assembly is located at the rear end of the machine head, both serving to achieve a seal at the end of the machine head housing.

[0018] The nozzle is disposed between the retaining ring and the machine head housing, and the nozzle is in clearance fit with the retaining ring, while the nozzle is in tight fit with the machine head housing or is integrally formed.

[0019] Optionally, in the dental handpiece head described above, the retaining ring has a first water-spraying tip at the protrusion of the nozzle.

[0020] Optionally, in the dental handpiece head described above, a first sealing washer is provided between the rear end face of the retaining ring and its corresponding bearing to achieve axial sealing.

[0021] Optionally, in the dental handpiece head described above, the labyrinth seal structure is a stepped second water-spraying tip, and the first sealing gasket is an L-shaped third water-spraying tip.

[0022] Optionally, in the above-mentioned dental handpiece head, a second sealing ring is provided between the nozzle and the head housing, and / or a third sealing ring is provided between the bearing and the head housing.

[0023] Optionally, in the dental handpiece head described above, the rear cover assembly is provided with an oil drain channel, and the oil drain channel is provided with a one-way seal for draining the mechanism oil.

[0024] Optionally, in the dental handpiece head described above, the oil drainage channel is a cavity with a small end opening and a large inner diameter, and the one-way seal is a flexible bowl-shaped structure.

[0025] The bowl-shaped structure has a groove at its open end, which abuts against the inner wall of one end of the cavity, and the bottom of the bowl-shaped structure is sealed to the oil outlet at the other end of the cavity.

[0026] Optionally, in the dental handpiece head described above, the rear cover assembly includes a rear cover body and a pressing cover. One end of the rear cover body is detachably connected to the head housing, and the other end includes a first inner ring and a first outer ring. The pressing cover includes a second inner ring and a second outer ring.

[0027] Both the first inner ring and the second inner ring are provided with limiting shoulders, which achieve axial limiting when they move in opposite directions and free movement when they move in relative directions;

[0028] The first outer ring and the second outer ring are always in frictional contact;

[0029] A spring is provided between the back cover body and the press cover to provide pressing force and elastic support.

[0030] Optionally, in the dental handpiece head described above, a second sealing gasket is provided between the first inner ring and the second inner ring.

[0031] Optionally, in the dental handpiece head described above, the outer wall of one end of the rear cover body is threadedly connected to the head housing, and the inner wall is sleeved on the corresponding bearing.

[0032] Optionally, in the dental handpiece head described above, a fourth sealing ring is provided between the bearing and the rear cover body, and / or a fifth sealing ring is provided between the rear cover body and the head housing.

[0033] Optionally, the dental handpiece head described above also includes a handle connected to the handpiece head, wherein the handle is provided with a water flow channel for introducing cleaning water, and / or a lubricating oil channel for introducing lubricating oil, and / or a gas channel for introducing gas.

[0034] The present invention also provides a dental handpiece, including the dental handpiece head described above.

[0035] This invention provides a dental handpiece head, including a bur and a clamping assembly. The clamping assembly has an internal mounting cavity for mounting the bur, and a seal is provided inside and / or outside the mounting cavity. The seal isolates the external space from the tail end of the mounting cavity. This industry-first seal at the clamping assembly and bur of a dental handpiece prevents saline solution, blood, etc., from entering the handpiece head during operation, ensuring the handpiece head maintains excellent sealing performance and extending the service life of the clamping assembly.

[0036] The present invention also provides a dental handpiece having the above-mentioned dental handpiece head, which has the same beneficial effects, and will not be described in detail here. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of a dental handpiece head in a specific embodiment of the present invention;

[0039] Figure 2 An axial cross-sectional view of the dental handpiece head in a specific embodiment of the present invention;

[0040] Figure 3 for Figure 2 A magnified view of the area at point I;

[0041] Figure 4 This is a schematic diagram of the retaining ring in a specific embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of a one-way seal in a specific embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the front end structure of a dental handpiece in a specific embodiment of the present invention.

[0044] In the image above:

[0045] A - Mobile phone head; 1 - Needle; 2 - Needle clamping assembly; 201 - Mounting cavity tail; 3 - Bearing; 4 - Head housing; 5 - Retaining ring; 501 - First water-spraying tip; 502 - Second water-spraying tip; 503 - Third water-spraying tip; 6 - Nozzle; 7 - Back cover assembly; 801 - First sealing gasket; 802 - Second sealing gasket; 901 - First sealing ring; 902 - Second sealing ring; 903 - Third sealing ring; 904 - Fourth sealing ring; 905 - Fifth sealing ring; 10 - One-way seal; 101 - Groove.

[0046] B-Handle. Detailed Implementation

[0047] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0048] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0049] In the description of this invention, "multiple" means two or more. If "first" and "second" are mentioned, they are only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0050] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0051] The core of this invention is to provide a dental handpiece head and a dental handpiece that can ensure that the handpiece head can always maintain good sealing performance.

[0052] To enable those skilled in the art to better understand the technical solutions provided by the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0053] This invention provides a dental handpiece head A, including a bur 1 and a bur clamping assembly 2. The bur clamping assembly 2 has a mounting cavity for mounting the bur 1. A seal is provided inside and / or outside the mounting cavity, wherein the seal is used to isolate the external space of the handpiece head from the tail end 201 of the mounting cavity. That is, regardless of whether the seal is located inside or outside the mounting cavity, its function is always to prevent water stains and dirt from the outside of the handpiece head from entering the internal space of the handpiece head through the gap between the bur 1 and the bur clamping assembly 2. At least one seal is provided. The tail end 201 of the mounting cavity is located near the internal space of the handpiece head, and its position is as follows: Figure 2 As shown, the tail end of the mounting cavity is connected to the internal space of the machine head.

[0054] It should be noted that the background of this invention is that researchers, while analyzing dental handpieces that had been discarded by hospitals and exceeded their service life, discovered that these handpieces would exhibit significant abnormal vibrations after continuous operation for a certain period. To address this, researchers disassembled the dental handpieces and observed that the components at the tail end of the bur clamp assembly were contaminated with dirt and showed signs of corrosion. Initially, researchers believed that this problem was entirely due to insufficient sealing between the rotating parts and the outer casing. However, to obtain a more accurate conclusion, researchers conducted extensive re-analysis and machine disassembly, ultimately discovering that some water stains and dirt entered the interior of the handpiece through the gap between the bur and the bur clamp assembly.

[0055] Based on the above research and development background, the industry's first dental handpiece features a sealed clamping assembly 2 and a bur 1, preventing saline solution, blood, and other substances from entering the handpiece head during operation. This ensures that the handpiece head maintains good sealing performance and extends the service life of the clamping assembly.

[0056] In a first specific embodiment, the sealing element is disposed inside the mounting cavity; that is, a positioning structure is provided on the inner wall of the mounting cavity, wherein the positioning structure is used to position the sealing element. The positioning structure includes an annular positioning groove or a positioning step. Specifically, the sealing element includes a first sealing ring 901, and the front end of the needle clamping assembly 2 has an annular positioning groove on its contact surface with the needle 1, and the first sealing ring 901 is disposed within the annular positioning groove. In particular, one end face of the sealing element can be fixed to the annular positioning groove or positioning step by means of bonding or the like. Specifically, the needle clamping assembly 2 and the needle 1 can be fitted into the interior of the needle clamping assembly 1 by an O-ring, tightly sealing the gap between the needle 1 and the needle clamping assembly 2.

[0057] In the second specific embodiment, the sealing element is disposed outside the mounting cavity. That is, a retaining ring 5 is sleeved on the front end of the needle clamping assembly 2, the needle 1 passes through the retaining ring 5 and the needle clamping assembly 2 is placed inside the retaining ring 5, and the sealing element is disposed within the cavity formed by the retaining ring 5, the needle clamping assembly 2 and the needle 1 to achieve sealing of the front end of the machine head. Specifically, as shown... Figure 1 As shown, the sealing element includes a first sealing ring 901, which is disposed in the cavity formed by the retaining ring 5, the needle clamping assembly 2, and the needle 1.

[0058] It should be noted that the first specific embodiment described above can be used alone, or the second specific embodiment described above can be used alone. Of course, a third specific embodiment can also be used, that is, an implementation method that combines the first specific embodiment and the second specific embodiment. The specific embodiment to be used can be adapted according to the actual situation, and will not be elaborated further here.

[0059] The pin clamp assembly 2 and the retaining ring 5 can be an integral structure or two separate structures, which can be detachably connected, such as by threaded connection or snap-fit.

[0060] Preferably, the inner wall of the front end of the retaining ring 5 is tightly fitted onto the needle 1, and the outer wall of the rear end is provided with a labyrinth-type sealing structure.

[0061] The dental handpiece of this solution also includes a bearing 3, a handpiece housing 4, a nozzle 6, and a back cover assembly 7.

[0062] Among them, the needle 1, the needle clamping assembly 2, the bearing 3 and the machine head housing 4 are tightly fitted together from the inside out.

[0063] The bur 1 is driven to rotate at high speed by a dental handpiece, assisting dentists in making cavities and repairing teeth. The bur clamp assembly 2 serves as the transmission mechanism between the bur 1 and the bearings 3. Multiple bearings 3 can be configured depending on the application; in this case, one bearing 3 is installed at each end of the bur 1.

[0064] The head shell 4 is a cylindrical structure with openings at both ends.

[0065] The retaining ring 5 and the nozzle 6 are located at the front end of the machine head, and the rear cover assembly 7 is located at the rear end of the machine head. Both are used to achieve the sealing of the ends of the machine head housing 4.

[0066] The nozzle 6 is positioned between the retaining ring 5 and the machine head housing 4, with the nozzle 6 and the retaining ring 5 having a clearance fit, and the nozzle 6 and the machine head housing 4 having a tight fit or being integrally formed.

[0067] It should be noted that the retaining ring 5 is mounted on the needle clamping assembly 2 (connected by interference fit, welding, or adhesive, etc.) and does not contact the nozzle 6. The labyrinth seal structure creates a labyrinthine gap between the rear end of the retaining ring 5 and the nozzle 6. The nozzle 6 and the handpiece housing 4 form the stator of the dental handpiece (i.e., it does not move when the dental handpiece is in operation). The retaining ring 5, the needle clamping assembly 2, and the bur 1 form the mover of the dental handpiece (i.e., it rotates when the dental handpiece is in operation).

[0068] When the dental handpiece is in operation, the non-contact labyrinth seal between the nozzle 6 and the retaining ring 5, combined with the centrifugal seal formed by the high-speed rotation of the retaining ring 5 and the needle clamp assembly 2, ensures that when water, blood, or other impurities from outside the dental handpiece attempt to enter, centrifugal force will throw them out, achieving a centrifugal seal effect. This overcomes the shortcomings of contact seals in existing technologies, prevents wear on the sealing material, and eliminates the need for strict control of the sealing gasket's dimensional accuracy to ensure precise interference fit between it and rotating parts. The handpiece head in this design maintains excellent sealing performance at all times, thereby extending the service life of the needle clamp assembly 2.

[0069] To improve the sealing of the dental handpiece tip, the retaining ring 5 is provided with a first water-spraying tip 501. In particular, the first water-spraying tip 501 is located at the protruding nozzle 6.

[0070] To further improve the sealing effect of the sealing type, a first sealing gasket 801 is provided between the rear end face of the retaining ring 5 and its corresponding bearing 3 to achieve axial sealing.

[0071] Specifically, the labyrinth-type sealing structure has a stepped second water-throwing tip 502, and the first sealing gasket 801 has an L-shaped third water-throwing tip 503. The outer diameter of the second water-throwing tip 502 gradually increases from front to back. The multi-stage steps on the outer circle of the sealing gasket, the multi-stage steps inside the nozzle 6, and the retaining ring 5 form a labyrinth-type sealing gap.

[0072] When the dental handpiece is in operation, the retaining ring 5 and the needle clamping assembly 2 rotate together at high speed, typically more than 100,000 revolutions per minute. The centrifugal force generated by the high speed creates three centrifugal seals through the three water-spraying tips of the retaining ring 5. When water, blood, or other impurities from outside the dental handpiece try to enter the handpiece, they are flung out by the centrifugal force, achieving the centrifugal seal effect.

[0073] A second sealing ring 902 is provided between the nozzle 6 and the head housing 4, and / or a third sealing ring 903 is provided between the bearing 3 and the head housing 4 to prevent foreign objects from entering the movement through the gaps between the components. The front end of the retaining ring 5 is designed as an end cap, with an opening on the end cap for the needle 1 to pass through. A first sealing ring 901 is provided between the inner cavity of the end cap and the front end of the needle 1 to prevent sewage from entering through the gap between the front opening of the retaining ring 5 and the needle 1.

[0074] Based on the above specific embodiments, the rear cover assembly 7 is provided with an oil drain channel, and a one-way seal 10 for draining the movement oil is provided in the oil drain channel.

[0075] Specifically, the oil drain channel is a cavity with a small end opening and a large inner diameter, and the one-way seal 10 is an elastic bowl-shaped structure.

[0076] The opening end of the bowl-shaped structure is slotted and abuts against the inner wall of one end of the cavity, while the bottom of the bowl-shaped structure is sealed at the oil outlet at the other end of the cavity.

[0077] The principle is that when subjected to outward air pressure from inside the dental handpiece, the one-way seal 10 moves upward. At this time, the oil drain channel opens, and the lubricating oil passes through the groove 101 of the one-way seal 10 from the sealing port and is discharged from the oil outlet of the back cover.

[0078] The one-way seal 10 prevents external foreign objects from entering the internal mechanism. However, when the doctor injects oil from the inside, the pressure pushes the one-way seal 10 upward, opening the seal and allowing oil to spray out from the oil outlet of the press cover through the groove 101 of the one-way seal 10.

[0079] Of course, the one-way seal 10 can also be a one-way valve or other oil discharge sealing mechanism that can achieve oil discharge without inflow, all of which are within the scope of protection of this case.

[0080] During lubrication and cleaning, oil can be sprayed out from the one-way seal 10 at the rear end of the head and the labyrinth seal gap at the front end. Because the back cover assembly 7 uses a one-way seal, the head is completely sealed externally while allowing oil to flow internally. Oil can be sprayed out from inside the phone, facilitating lubrication and cleaning by the doctor. The lubricating oil can flow quickly and freely inside the mechanism, allowing it to easily reach every part for lubrication. It also removes old lubricating oil, and prevents saline solution and blood from entering the head, which could cause the bearings 3 and gears to rust or even fail.

[0081] The above settings effectively overcome problems such as the inability of lubricating oil to spray out after being injected from the curved end of the phone after the sealing gasket is used, the inability of lubricating oil to be injected into all parts of the phone, and the possibility of the phone falling and getting damaged due to excessive internal pressure during the oil injection process.

[0082] In a specific embodiment, the rear cover assembly 7 includes a rear cover body and a press cover. One end of the rear cover body is detachably connected to the head housing 4, and the other end includes a first inner ring and a first outer ring. The press cover includes a second inner ring and a second outer ring.

[0083] Both the first inner ring and the second inner ring are provided with limiting shoulders, which achieve axial limitation when moving in opposite directions and free movement when moving in opposite directions.

[0084] The first outer ring and the second outer ring are always in frictional contact.

[0085] A spring is provided between the back cover body and the press cover to provide elastic force and support when pressed.

[0086] The spring is compressed within the space formed by the back cover body and the press cover, and the resulting elastic support force causes the press cover and the back cover body to tend to move in opposite directions. Driven by the press cover, the limiting shoulders between the press cover and the back cover body fit tightly together to achieve a seal of the internal space.

[0087] When a dental handpiece needs lubrication and cleaning, press the press cap. The retaining shoulder between the press cap and the back cover body separates to create a passage for the discharge of cleaning lubricant.

[0088] To further improve axial sealing, a second sealing gasket 802 is provided between the first inner ring and the second inner ring.

[0089] The outer wall of one end of the rear cover body is connected to the machine head housing 4 by threads, and the inner wall is sleeved on the corresponding bearing 3.

[0090] Similarly, a fourth sealing ring 904 is provided between the bearing 3 and the rear cover body, and / or a fifth sealing ring 905 is provided between the rear cover body and the machine head housing 4.

[0091] like Figure 2 It can be seen that a first sealing ring 901 is provided between the needle 1 and the retaining ring 5, a second sealing ring 902 is provided between the nozzle 6 and the head housing 4 (this seal can be omitted when the process allows the head housing 4 and the nozzle 6 to be made as one piece), a third sealing ring 903 is provided between the bearing 3 and the head housing 4, a fourth sealing ring 904 is provided between the rear cover body and the head housing 4, and a fifth sealing ring 905 is provided between the bearing 3 and the rear cover body. Combined with the labyrinth sealing structure and the one-way seal 10, the above settings can achieve all-round sealing of the dental handpiece head.

[0092] Preferably, the first sealing ring 901, the second sealing ring 902, the third sealing ring 903, the fourth sealing ring 904 and the fifth sealing ring 905 can be O-rings. Of course, other types of sealing rings can be selected according to actual needs, and no further limitations are made here.

[0093] In addition, the present invention also includes a handle B connected to the machine head, wherein the handle B is provided with a water flow channel for introducing cleaning water, and / or a lubricating oil channel for introducing lubricating oil, and / or a gas channel for introducing gas.

[0094] The main advantage of this case is:

[0095] 1) The seal between the front end of the machine head housing 4 and the needle clamping assembly 2 adopts a non-contact labyrinth seal and a centrifugal seal, which avoids the shortcomings of the contact seal in the prior art.

[0096] 2) The industry's first dental handpiece features a sealed clamping assembly 2 and bur 1, preventing saline solution, blood, etc. from entering the handpiece head during operation and extending the service life of the clamping assembly 2.

[0097] 3) The back cover assembly 7 of this invention adopts a one-way seal, which completely seals the head of the device to the outside, preventing foreign objects from entering. At the same time, oil can circulate inside. By injecting oil for lubrication, foreign oil from internal mechanical wear can be discharged from the phone, making it convenient for doctors to inject oil for lubrication and cleaning.

[0098] Based on the above three points, the sealing structure of the present invention effectively protects the head mechanism components, extends their service life, and ensures the long-term stable operation of the curved head, greatly improving the market competitiveness of dental handpieces.

[0099] In addition, the present invention also provides a dental handpiece, including the dental handpiece head described above.

[0100] Since dental handpieces have the aforementioned dental handpiece head, they also have the beneficial effects of the dental handpiece head. Please refer to the above content for details, which will not be repeated here.

[0101] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0102] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A dental handpiece head, characterized in that, The device includes a needle and a needle clamping assembly, the needle clamping assembly having a mounting cavity for mounting the needle; it also includes a bearing and a machine head housing, the needle, the needle clamping assembly, the bearing and the machine head housing being tightly fitted together sequentially from the inside out; A sealing element is provided on the outside of the mounting cavity, wherein the sealing element is used to isolate the external space from the tail of the mounting cavity; The needle clamping assembly includes a retaining ring, which is sleeved on the front end of the needle clamping assembly. The bur passes through the retaining ring and the needle clamping assembly is placed inside the retaining ring. The sealing element is disposed in the cavity formed by the retaining ring, the needle clamping assembly, and the bur to achieve sealing at the front end of the handpiece. The retaining ring, the needle clamping assembly, and the bur constitute the moving part of the dental handpiece. The outer wall of the rear end of the retaining ring is provided with a labyrinth-type sealing structure; A first sealing washer is provided between the rear end face of the retaining ring and the corresponding bearing to achieve axial sealing; The labyrinth-type sealing structure has a stepped second water-throwing tip, and the first sealing gasket has an L-shaped third water-throwing tip.

2. The dental handpiece head according to claim 1, characterized in that, The sealing element is the first sealing ring.

3. The dental handpiece head according to claim 1, characterized in that, The retaining ring and the clamping pin assembly are an integral structure; Alternatively, the retaining ring and the clamping pin assembly may be detachably connected.

4. The dental handpiece head according to claim 1, characterized in that, It also includes the nozzle and back cover assembly; among which, The machine head housing is a cylindrical structure with openings at both ends; The nozzle is located at the front end of the machine head, and the rear cover assembly is located at the rear end of the machine head, both serving to achieve a seal at the end of the machine head housing. The nozzle is disposed between the retaining ring and the machine head housing, and the nozzle is in clearance fit with the retaining ring, while the nozzle is in tight fit with the machine head housing or is integrally formed.

5. The dental handpiece head according to claim 4, characterized in that, The retaining ring has a first water-spraying tip at the protrusion of the nozzle.

6. The dental handpiece head according to claim 4, characterized in that, A second sealing ring is provided between the nozzle and the head housing, and / or a third sealing ring is provided between the bearing and the head housing.

7. The dental handpiece head according to any one of claims 4-6, characterized in that, The rear cover assembly is provided with an oil drain channel, and the oil drain channel is provided with a one-way seal for draining the movement oil.

8. The dental handpiece head according to claim 7, characterized in that, The oil drain channel is a cavity with a small end opening and a large inner diameter, and the one-way seal is a flexible bowl-shaped structure; The bowl-shaped structure has a groove at its open end, which abuts against the inner wall of one end of the cavity, and the bottom of the bowl-shaped structure is sealed to the oil outlet at the other end of the cavity.

9. The dental handpiece head according to claim 4, characterized in that, The rear cover assembly includes a rear cover body and a press cover. One end of the rear cover body is detachably connected to the head housing, and the other end includes a first inner ring and a first outer ring. The press cover includes a second inner ring and a second outer ring. Both the first inner ring and the second inner ring are provided with limiting shoulders, which achieve axial limiting when they move in opposite directions and free movement when they move in relative directions; The first outer ring and the second outer ring are always in frictional contact; A spring is provided between the back cover body and the press cover to provide pressing force and elastic support.

10. The dental handpiece head according to claim 9, characterized in that, A second sealing gasket is provided between the first inner ring and the second inner ring.

11. The dental handpiece head according to claim 9, characterized in that, The outer wall of one end of the rear cover body is threaded to the machine head housing, and the inner wall is sleeved on the corresponding bearing.

12. The dental handpiece head according to claim 9, characterized in that, A fourth sealing ring is provided between the bearing and the rear cover body, and / or a fifth sealing ring is provided between the rear cover body and the machine head housing.

13. A dental handpiece, characterized in that, The dental handpiece head includes any one of claims 1-12, and a handle connected to the dental handpiece head, wherein the handle is provided with a water flow channel for introducing cleaning water, and / or a lubricating oil channel for introducing lubricating oil, and / or a gas channel for introducing gas.

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