A dental handpiece

Abstract

A dental mobile phone comprises a cylinder, a wind wheel rotatably arranged in the cylinder, a central axis pivotally connected to the wind wheel and rotating with the wind wheel, a bearing supporting the rotation of the central axis, and a sealing member, wherein the cylinder comprises an axial open end, the sealing member is trumpet-shaped and arranged between the open end of the cylinder and the bearing, the sealing member comprises a sealing portion annularly sleeved on the central axis, the sealing portion is arranged in contact with the outer cylindrical surface of the central axis, the sealing member of the dental mobile phone of the present invention produces corresponding deformation under the action of the internal and external pressure difference, opens outward or contracts inward, when in use, the sealing member is separated from the central axis to facilitate the rotation of the central axis, when stopped, the sealing member and the central axis are tightly embraced to form a good braking and sealing effect, and prevent external substances from being sucked back into the cylinder.

Description

Technical Field

[0001] The invention relates to the technical field of medical instruments, and in particular to a dental mobile phone. Background Art

[0002] Dental turbine handpieces generate power by blowing compressed air into the wind wheel to rotate in the wind tube. The turbine handpieces currently on the market can drive the central axis at a speed of up to 300,000 to 400,000 revolutions per minute when the wind wheel is working.

[0003] However, during the treatment of patients, doctors often need to stop the turbine handpiece to replace the needle or observe the patient's oral condition. Due to inertia, the central axis and wind wheel will continue to rotate for 4-5 seconds after stopping, which will cause negative pressure inside the wind tube of the turbine handpiece, sucking the blood, water, and various debris produced by grinding teeth in the patient's mouth back into the wind tube. On the one hand, the inhaled debris may enter the handpiece bearing, seriously affecting the safety and service life of the bearing; on the other hand, blood and water enter the barrel and cause contamination, and even subsequent disinfection cannot completely avoid cross infection of patients. Summary of the invention

[0004] In view of this, a dental handpiece is provided which can effectively prevent the back suction during shutdown.

[0005] A dental handpiece comprises a barrel, a wind wheel rotatably arranged in the barrel, a central shaft pivotally connected to the wind wheel and rotating with the wind wheel, a bearing supporting the rotation of the central shaft, and a sealing member, wherein the barrel comprises an axial opening end, the sealing member is trumpet-shaped and arranged between the opening end of the barrel and the bearing, the sealing member comprises a sealing portion annularly sleeved on the central shaft, and the sealing portion is arranged in contact with the outer cylindrical surface of the central shaft.

[0006] Preferably, the sealing member is an elastic element with a hardness of 50-70 degrees. In a natural state, the inner diameter of the sealing portion is smaller than the diameter of the central axis, and the sealing portion is tightly matched with the outer cylindrical surface of the central axis.

[0007] Preferably, the sealing portion is a curved surface structure that is arched toward the outer cylindrical surface of the central axis, and the corresponding curved surface radius is 1-3 mm.

[0008] Preferably, the radial inner side surface of the sealing portion is a cylindrical surface, and the cylindrical surface is disposed in contact with the outer cylindrical surface of the central axis.

[0009] Preferably, the sealing member further comprises an annular mounting portion arranged around the sealing portion, the mounting portion has a thickness of 0.4-1.0 mm, and the sealing portion has a thickness of 0.1-0.3 mm.

[0010] Preferably, a bearing seat is provided in the cylinder, the bearing seat is formed with a bearing hole for assembling the bearing, and the mounting portion is provided between the bearing and the bearing seat and is clamped and flattened by the bearing and the bearing seat.

[0011] A dental handpiece comprises a barrel, a wind wheel rotatably arranged in the barrel, a central axis pivotally connected to the wind wheel and rotating with the wind wheel, a bearing supporting the rotation of the central axis, and a sealing member, wherein the barrel comprises an axial opening end, the sealing member is trumpet-shaped, comprises a sealing portion sleeved with the central axis and a mounting portion surrounding the sealing portion, the mounting portion being arranged between the opening end of the barrel and the bearing and being clamped flat.

[0012] Preferably, a bearing seat is provided in the cylinder, the bearing seat is formed with a bearing hole and an annular groove, the bearing is provided in the bearing hole, the mounting portion is received in the annular groove and clamped between the bearing and the bearing seat, and the depth of the annular groove is smaller than the thickness of the mounting portion in a natural state.

[0013] Preferably, the cross-section of the mounting portion is circular or elliptical, and the cross-section of the annular groove is square or rectangular.

[0014] Preferably, the bearing includes a first bearing and a second bearing, and the bearing seat includes a first bearing seat and a second bearing seat. The first bearing and the second bearing are respectively arranged on both axial sides of the wind wheel, the first bearing is accommodated in the first bearing seat and is close to the opening end of the cylinder, and the second bearing is accommodated in the second bearing seat and is away from the opening end of the cylinder, an elastic gasket is arranged between the axial side end of the second bearing and the second bearing seat, the annular groove is formed on the first bearing seat, and the mounting portion is clamped between the axial side end of the first bearing and the first bearing seat.

[0015] Preferably, a flat washer is provided between the axial side end of the first bearing and the first bearing seat, and the mounting portion is sandwiched between the flat washer and the first bearing seat.

[0016] Preferably, the thickness of the mounting portion is greater than the thickness of the sealing portion, and the sealing portion is tightly matched with the outer cylindrical surface of the central shaft.

[0017] Compared with the prior art, the dental mobile phone of the present invention opens outward or contracts inward through the corresponding deformation of its seal under the action of the internal and external pressure difference. When in use, the seal is separated from the central axis to facilitate the rotation of the central axis. When stopped, the seal and the central axis are tightly embraced to form a good braking and sealing effect, avoiding the back-sucking of external substances into the cylinder body. On the one hand, it ensures the safety and service life of the bearing, and on the other hand, it avoids cross infection of patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a dental mobile phone of the present invention.

[0019] Figure 2 for Figure 1 Cross-sectional view of dental handpiece shown.

[0020] Figure 3 for Figure 2 A cross-sectional view of the seal of the dental handpiece is shown.

[0021] Figure 4 for Figure 2 Magnified view of middle circle IV.

[0022] Figure 5 for Figure 1 The diagram shows the status of the dental handpiece when in use.

[0023] Figure 6 for Figure 1 The diagram shows the status of the dental handpiece when it is stopped. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. One or more embodiments of the present invention are exemplarily given in the drawings to make the understanding of the technical solution disclosed in the present invention more accurate and thorough. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments described below.

[0025] like Figure 1-2 As shown, a dental handpiece according to an embodiment of the present invention comprises a handpiece 10 and a handle 30 connected to the handpiece 10. The handle 30 is convenient for a user, such as a doctor, to hold. The handpiece 10 comprises a barrel 11, a wind wheel 12 rotatably disposed in the barrel 11, a central shaft 13 pivotally connected to the wind wheel 12, a bearing 14 supporting the rotation of the central shaft 13, and a sealing member 20.

[0026] The cylinder 11 is a hollow cylindrical structure as a whole, and a receiving chamber 110 is formed inside for installing the wind wheel 12. The cylinder 11 is open at both axial ends, and the rear end cover of the cylinder 11 is provided with a rear cover 15. The central axis 13 is fixedly passed through the center of the wind wheel 12, and its front and rear ends both extend out of the wind wheel 12. The rear end of the central axis 13 is rotatably supported in the center of the rear cover 15, and the front end extends out of the cylinder 11 from the front end opening of the cylinder 11 to connect with medical instruments, such as a needle 40. Corresponding to the wind wheel 12, a main air channel 32 and an exhaust channel 34 are formed on the handle 30, and the main air channel 32 and the exhaust channel 34 are both connected with the receiving chamber 110, and are respectively used for the inflow and outflow of compressed air.

[0027] When the dental handpiece of the present invention is in use, compressed air is delivered to the accommodating chamber 110 through the main air channel 32, driving the wind wheel 12 to rotate at a high speed, thereby driving the central axis 13 and medical instruments such as the needle 40 connected to the central axis 13 to rotate, thereby grinding the teeth. Usually, the rotation speed of the central axis 13 during operation can be as high as 300,000 to 400,000 revolutions per minute. The compressed air flows along the wall of the accommodating chamber 110 as the wind wheel 12 rotates, and finally flows out of the accommodating chamber 110 through the exhaust channel 34. In order to ensure the effectiveness of the torque transmission between the wind wheel 12 and the central axis 13, the wind wheel 12 and the central axis 13 can also form a limit in the circumferential direction by means of bonding, snapping, etc., and the two rotate synchronously under the drive of the compressed air.

[0028] There are two bearings 14, which are referred to as the first bearing 14a and the second bearing 14b for the convenience of description. The first bearing 14a and the second bearing 14b are respectively sleeved on the front end and the rear end of the central shaft 13, and are respectively located at the front side and the rear side of the wind wheel 12 in the axial direction, so as to ensure the balance and stability of the rotation of the wind wheel 12 and the central shaft 13 and reduce the generation of noise. In this embodiment, the first and second bearings 14a and 14b are both ball bearings, which form rolling friction during the rotation of the central shaft 13, effectively reducing wear. It should be understood that the first and second bearings 14a and 14b can also be selected from sliding bearings, ceramic bearings, etc.; in addition, the first and second bearings 14a and 14b can also be selected from different types of bearings, not limited to the specific embodiments.

[0029] The first bearing 14a is assembled into the cylinder 11 through the first bearing seat 16, and the second bearing 14b is assembled into the cylinder 11 through the second bearing seat 17. In this embodiment, the outer edge of the front side end of the first bearing seat 16 and the inner edge of the front side end of the cylinder 11 form a matching step, which abuts against each other in the axial direction; the outer wall surface of the second bearing seat 17 and the inner wall surface of the rear side end of the cylinder 11 form a matching thread, and the two are screwed and fixed; the rear cover 15 is hooked and connected to the end of the second bearing seat 17. It should be understood that the first bearing seat 16 and / or the second bearing seats 16, 17 can be formed integrally in the cylinder 11, or the second bearing seat 17 and the rear cover 15 can be an integral structure.

[0030] A first bearing hole is formed in the center of the first bearing seat 16 on the side facing the wind wheel 12, for assembling the first bearing 14a. Preferably, a flat washer 18 is disposed between the first bearing seat 16 and the axial front end of the first bearing 14a. The sealing member 20 is sleeved on the central axis 13 and is located on the front side of the first bearing 14a. In this embodiment, it is sandwiched between the flat washer 18 and the first bearing seat 16, and is used to form a seal between the first bearing 14a and the front end of the barrel 11 when the dental mobile phone of the present invention is stopped. It should be understood that the flat washer 18 between the first bearing seat 16 and the first bearing 14a can be omitted, and in this case, the sealing member 20 is sandwiched between the first bearing 14a and the first bearing seat 16.

[0031] A second bearing hole is formed in the center of the second bearing seat 17 for assembling the second bearing 14b. An elastic member 19, such as an elastic gasket, is disposed between the second bearing seat 17 and the axial rear end of the second bearing 14b. During assembly, the first bearing seat 16, the seal 20, the flat washer 18, the first bearing 14a, the central axis 13 and the wind wheel 12 are sequentially assembled into the cylinder 11; the elastic member 19 and the second bearing 14b are assembled into the second bearing seat 17, and then the second bearing seat 17 is screwed onto the cylinder 11. During the screwing process, the inner rings of the first bearing 14a and the second bearing 14b clamp the wind wheel 12, and the elastic member 19 is compressed and deformed to form a forward preload and acts on the seal 20 through the second bearing 14b, the wind wheel 12, the first bearing 14a and the flat washer 18, so that the seal 20 is clamped and flattened.

[0032] Please also see Figure 3 The seal 20 is made of materials such as fluorine rubber and hydrogenated nitrile rubber, and its hardness is preferably 50-70 degrees. It not only has the advantages of oil resistance, wear resistance, and high temperature resistance, but also can be directly molded for injection molding, and has low production costs. On the whole, the seal 20 is annular, including a mounting portion 22 located on its outer edge, and a sealing portion 24 located in the mounting portion 22. A through hole 26 is formed in the center of the sealing portion 24, which is used to sleeve the central axis 13. The radial inner side surface of the sealing portion 24, that is, the surface surrounding the through hole 26, serves as an active surface 28, which is in close contact with the outer cylindrical surface of the central axis 13. Preferably, the through hole 26 is a cylindrical hole, and the active surface 28 is a cylindrical surface. The diameter D1 of the active surface 28 is preferably 2.8-3.0 mm, which is slightly smaller than the diameter of the central axis 13.

[0033] The mounting portion 22 is annular in shape as a whole, and its cross section is circular or elliptical, similar to an O-ring. In this embodiment, the cross section of the mounting portion 22 in a natural state is circular, and the diameter D2 of the circular cross section is 0.4-1.0 mm, that is, the thickness of the mounting portion 22 in the axial direction of the cylinder 11 / central axis 13 is 0.4-1.0 mm. Preferably, an annular groove 160 is formed on the first bearing seat 16 for accommodating and positioning the mounting portion 22 of the seal 20. Figure 4 As shown in FIG. 1 , the cross section of the annular groove 160 is square or rectangular, which is different from the cross section of the mounting portion 22, and can provide space for the deformation of the mounting portion 22. The axial depth of the annular groove 160 is less than the thickness D2 of the mounting portion 22 in the natural state. After assembly, the mounting portion 22 is sandwiched between the flat washer 18 and the first mounting seat 16 and is flattened. When flattened, the cross section of the mounting portion 22 is roughly elliptical, as shown in FIG. Figure 3 As shown by the dotted line, after being flattened, the thickness D3 of the mounting portion 22 is equivalent to the axial depth of the annular groove 160, and the difference between the thickness D3 and the original thickness D2 is 0.05-0.1 mm.

[0034] The sealing portion 24 is trumpet-shaped as a whole, extending from the inner edge of the mounting portion 22 radially inward and axially toward the front end of the cylinder 11. The sealing portion 24 is tapered from back to front along the axial direction of the seal 20. Preferably, the thickness of the sealing portion 24 is smaller than the diameter of the mounting portion 22, so that the sealing portion 24 has better elastic deformation ability and the mounting portion 22 can be better fixed. Preferably, the thickness T of the sealing portion 24 in the axial direction of the cylinder 11 / central axis 13 is 0.1-0.3mm. In this embodiment, the sealing portion 24 is an arc surface structure arched toward the central axis 13, and the corresponding arc surface radius R is 1-3mm.

[0035] like Figure 4 As shown, when the dental mobile phone of the present invention is not in use, the action surface 28 of the sealing part 24 is tightly wrapped on the outer cylindrical surface of the central axis 13. Since the diameter of the action surface 28 is slightly smaller than the diameter of the central axis 13, the seal 20 generates a certain elastic deformation when assembled with the central axis 13. After assembly, the seal 20 and the central axis 13 are tightly matched, and the action surface 28 hugs the outer cylindrical surface of the central axis 13. The two are in close contact to form a seamless connection, and the components in the cylinder 11, especially the first bearing 14a and the second bearing 14b, are isolated from the outside to ensure the cleanliness of the internal components of the cylinder 11. It should be noted that the outer cylindrical surface of the central axis 13 referred to in the present invention refers to the circumferential outer wall surface of the central axis 13, which is different from its axial end face and chamfered surface. It is cylindrical as a whole, but it does not exclude the formation of small notches and other structures on the circumferential outer wall surface of the central axis 13. In other words, the outer cylindrical surface of the central axis 13 referred to in the present invention is not limited to a complete cylindrical surface.

[0036] like Figure 5 As shown, when the dental handpiece of the present invention is in use, compressed air is introduced into the barrel 11 to drive the wind wheel 12 and the central axis 13 to rotate, and a small amount of compressed air flows from the gap of the first bearing 14a to the seal 20. Since the air pressure of the compressed air is much greater than the air pressure of the external environment, the compressed air exerts an outward force on the seal 24, causing the seal 24 to deform and open outward, forming a gap between the action surface 28 of the seal 24 and the outer cylindrical surface of the central axis 13. In this way, the rotation of the central axis 13 is not restricted by the seal 20, effectively reducing friction and ensuring the high-speed rotation of the central axis 13. During the operation of the dental handpiece, due to the pressure difference between the inside and outside of the barrel 11, external blood, impurities, etc. cannot enter the barrel 11 through the gap between the seal 20 and the central axis 13.

[0037] like Figure 6 As shown, when the dental handpiece of the present invention is paused during use, the central axis 13 and the wind wheel 12 will continue to rotate due to inertia. During the shutdown process, firstly, since compressed air is no longer supplied to the accommodating chamber 110, the air pressure in the cylinder 11 drops rapidly, and the sealing portion 24 recovers its deformation and hugs the central axis 13; thereafter, since the central axis 13 and the wind wheel 12 continue to rotate, the air in the cylinder 11 is discharged, and a negative pressure is formed in the cylinder 11. The external ambient air forms an inward force on the sealing portion 24, and the sealing portion 24 deforms and shrinks inward, further hugging the central axis 13 and forming a sufficiently strong force between its action surface 28 and the outer cylindrical surface of the central axis 13, on the one hand, a braking effect is formed on the central axis 13, so that the central axis 13 can stop rotating quickly. According to tests, the central axis 13 of the dental mobile phone of the present invention can stop rotating within 2 seconds after shutdown; on the other hand, the sufficiently strong force also prevents external substances, including blood, impurities, debris, etc. from entering the cylinder 11, that is, damage to internal components, especially bearings 14a, 14b, is avoided, and cross infection of patients is also avoided.

[0038] In summary, the present invention provides a seal 20, and the seal 20 produces corresponding deformation under the action of the internal and external pressure difference, and opens outward or contracts inward. When in use, the seal 20 is separated from the central axis 13 to facilitate the rotation of the central axis 13, and when stopped, the seal 20 and the central axis 13 are tightly embraced to form a good braking and sealing effect, thereby preventing foreign substances from entering the cylinder 11. In order to produce a good deformation effect, the sealing portion 24 of the seal 20 is thinner in thickness than its mounting portion 22, and the relatively thick mounting portion 22 can have sufficient thickness during the assembly process to deform under pressure to provide a good seal at the mounting position of the seal 20, further enhancing the overall sealing effect. In addition, the sealing portion 24 is a curved surface structure that arches toward the central axis 13. When deformed by force, its deformation direction is consistent with the bending direction of the inner edge of the sealing portion 24, so that deformation is easier and the effect is better.

[0039] It should be noted that the present invention is not limited to the above-mentioned embodiments. Based on the creative spirit of the present invention, those skilled in the art may also make other changes. These changes made based on the creative spirit of the present invention should be included in the scope of protection required by the present invention.

Claims

1. A dental handpiece, comprising a barrel, a wind wheel rotatably disposed in the barrel, a central shaft pivotally connected to the wind wheel and rotating with the wind wheel, a bearing supporting the rotation of the central shaft, and a sealing member, wherein the barrel comprises an axial open end, characterized in that: The sealing member is trumpet-shaped and comprises a sealing portion sleeved with the central axis and a mounting portion surrounding the sealing portion, wherein the mounting portion is disposed between the open end of the cylinder and the bearing and is clamped flat; A bearing seat is provided in the cylinder, the bearing seat is formed with a bearing hole and an annular groove, the bearing is provided in the bearing hole, the mounting portion is received in the annular groove and sandwiched between the bearing and the bearing seat, and the depth of the annular groove is less than the thickness of the mounting portion in a natural state; The diameter of the annular groove is smaller than the diameter of the bearing hole, so that a step is formed between the annular groove and the bottom of the bearing hole, and the bearing abuts against the step.

2. The dental handpiece according to claim 1, characterized in that: The cross section of the mounting portion is circular or elliptical, and the cross section of the annular groove is square or rectangular.

3. The dental handpiece according to claim 1, characterized in that: The bearing includes a first bearing and a second bearing, and the bearing seat includes a first bearing seat and a second bearing seat. The first bearing and the second bearing are respectively arranged on both axial sides of the wind wheel. The first bearing is accommodated in the first bearing seat and is close to the opening end of the cylinder, and the second bearing is accommodated in the second bearing seat and is away from the opening end of the cylinder. An elastic gasket is arranged between the axial side end of the second bearing and the second bearing seat. The annular groove is formed on the first bearing seat to form the step at the bottom of the bearing hole of the first bearing seat. The mounting portion is clamped between the axial side end of the first bearing and the first bearing seat.

4. The dental handpiece according to claim 3, characterized in that: A flat washer is arranged between the axial side end of the first bearing and the first bearing seat, the flat washer is arranged on the step, and the mounting portion is sandwiched between the flat washer and the first bearing seat.

5. The dental handpiece according to any one of claims 1 to 4, characterized in that: The thickness of the mounting portion is greater than the thickness of the sealing portion, and the sealing portion is tightly matched with the outer cylindrical surface of the central shaft.

6. The dental handpiece according to claim 5, characterized in that: The hardness of the sealing member is 50-70 degrees.

7. The dental handpiece according to claim 5, characterized in that: The sealing portion is a curved surface structure that arches toward the outer cylindrical surface of the central axis, and the corresponding curved surface radius is 1-3 mm.

8. The dental handpiece according to claim 5, characterized in that: The radial inner side surface of the sealing portion is a cylindrical surface, and the cylindrical surface is arranged in contact with the outer cylindrical surface of the central shaft.

9. The dental handpiece according to claim 5, characterized in that: The thickness of the mounting portion is 0.4-1.0 mm, and the thickness of the sealing portion is 0.1-0.3 mm.

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