Dental contra-angle handpiece and root canal treatment instrument

Abstract

The present invention discloses a dental contra-angle handpiece and a root canal treatment instrument, and relates to the technical field of oral medical instruments. The contra-angle handpiece comprises a cylindrical shell, an input gear box is arranged at the first end of the cylindrical shell, a machine head is arranged at the second end of the cylindrical shell, the input gear box comprises an input gear shaft, a long gear shaft is arranged in the cylindrical shell, the machine head comprises a movement gear and a shaft core fixedly connected to the movement gear, the movement gear is connected to the input gear shaft through the long gear shaft, the axis of the long gear shaft is in the same straight line as the axis of the input gear shaft, and the angle between the axis of the shaft core and the axis of the long gear shaft is 5° to 90°. The contra-angle handpiece can enable doctors to obtain a larger working space and field of view when performing root canal treatment of posterior teeth, and reduce the difficulty of operation during root canal treatment of posterior teeth.

Description

Technical Field

[0001] The present invention relates to the technical field of oral medical instruments, and in particular to a dental contra-angle handpiece and a root canal treatment instrument. Background Art

[0002] Root canal therapy, also known as endodontic treatment, is a surgical procedure in dentistry to treat pulp necrosis and root infection. Root canal therapy mainly targets the inside of the tooth and is the most effective treatment for acute pulpitis. By removing the necrotic tissue in the pulp cavity and then refilling the pulp cavity after disinfection, the compression and stimulation of the diseased tissue on the dental nerve can be relieved to prevent the tooth from further deteriorating.

[0003] In order to reduce the treatment time and relieve the pain of the patient during root canal treatment, root canal treatment instruments are usually needed. In the root canal treatment instruments currently on the market, dental contra-angle handpieces all form an angle between the input shaft and the transmission shaft immediately following. In this form, the shell at the corner must be designed to be large enough and have a certain angle. The final product not only has an angle at the head, but also has an additional angle at the connection with the handle.

[0004] The above-mentioned setting has too many bends, which makes it inconvenient for doctors to obtain a larger working space and field of view when performing root canal treatment, especially root canal treatment of posterior teeth, and affects the doctor's operation during root canal treatment. Summary of the invention

[0005] The object of the present invention is to provide a dental contra-angle handpiece and a root canal treatment instrument, which can enable a doctor to obtain a larger working space and visual field when performing root canal treatment on posterior teeth, thereby reducing the difficulty of operation during root canal treatment on posterior teeth.

[0006] The embodiment of the present invention is achieved as follows:

[0007] According to one aspect of an embodiment of the present invention, a dental contra-angle handpiece is provided, comprising a cylindrical shell, an input gear box is disposed at a first end of the cylindrical shell, a handpiece is disposed at a second end of the cylindrical shell, the input gear box comprises an input gear shaft, a long gear shaft is disposed in the cylindrical shell, the handpiece comprises a movement gear and an axial core fixedly connected to the movement gear, the axial core is used to insert a working tip, the movement gear is transmission-connected to the input gear shaft via the long gear shaft, the axis of the long gear shaft is in the same straight line as the axis of the input gear shaft, and the angle between the axis of the axial core and the axis of the long gear shaft is 5° to 90°.

[0008] Optionally, an eccentric gear shaft and an eccentric shaft carrier are also provided in the cylindrical shell, the eccentric shaft carrier is provided with an eccentric hole along the axial direction, the eccentric gear shaft is arranged through the eccentric hole, the axis of the eccentric gear shaft is parallel to the axis of the long gear shaft, and the movement gear is located on the side of the axis of the long gear shaft away from the eccentric gear shaft.

[0009] Optionally, a first gear is provided at one end of the input gear shaft, a second gear and a third gear are respectively provided at both ends of the eccentric gear shaft, a fourth gear is provided at one end of the long gear shaft close to the eccentric gear shaft, the first gear and the second gear are externally meshed, and the third gear and the fourth gear are internally meshed.

[0010] Optionally, a long shaft sleeve and a tightening ring are further provided in the cylindrical shell, an annular groove is provided on the inner wall of the cylindrical shell, and the long shaft sleeve is correspondingly provided with an annular protrusion, and the annular protrusion abuts against the annular groove. The input gear box also includes a gear box shell connected to the first end of the cylindrical shell, and the long shaft sleeve, the tightening ring, the eccentric shaft carrier and the gear box shell abut in sequence.

[0011] Optionally, a fifth gear is provided at one end of the long gear shaft away from the eccentric gear shaft, and the fifth gear meshes with the movement gear. The movement gear is located away from the axis of the long gear shaft and away from the shaft core and inserted into the side of the working tip.

[0012] Optionally, a first positioning hole is provided on a side of the eccentric shaft carrier facing the input gear box, and a second positioning hole is correspondingly provided on a side of the gear box housing facing the eccentric shaft carrier, and the first positioning hole and the second positioning hole are positioned by positioning pins.

[0013] Optionally, bearings are arranged in pairs in the long shaft sleeve, the eccentric shaft carrier and the gear box housing, and the bearings are respectively located between the long shaft sleeve and the long gear shaft, between the eccentric shaft carrier and the eccentric gear shaft, and between the gear box housing and the input gear shaft.

[0014] Optionally, the fourth gear includes a fixing portion and a meshing portion which are connected to each other, the fixing portion is used to be fixedly connected to the long gear shaft, and the meshing portion is provided with internal gear teeth for meshing with the third gear.

[0015] Optionally, a coupling is provided at one end of the input gear shaft away from the first gear, and the coupling is used for transmission connection with the drive motor.

[0016] Another aspect of the embodiments of the present invention provides a root canal treatment apparatus, comprising the dental contra-angle handpiece as described in any one of the above items and a handle connected to the dental contra-angle handpiece.

[0017] The beneficial effects of the embodiments of the present invention include:

[0018] The dental contra-angle handpiece and the root canal treatment instrument provided by the embodiment of the present invention, through the cylindrical shell, are convenient for doctors to better hold the dental contra-angle handpiece, and at the same time obtain a better viewing angle and operating space. Through the input gear box arranged at the first end of the cylindrical shell and the handpiece arranged at the second end of the cylindrical shell, as well as the input gear shaft of the input gear box and the core gear of the handpiece, the core gear can be connected to the input gear shaft through the long gear shaft arranged in the cylindrical shell. In order to ensure the stability of the transmission connection and the lateral size of the cylindrical shell is not increased, so as not to affect the normal viewing angle, it is also necessary to ensure that the axis of the long gear shaft and the axis of the input gear shaft are in the same straight line to ensure the lateral size of the cylindrical shell. In addition, when the dental contra-angle handpiece is used normally, in order to ensure that the angle adapts to the space of the oral cavity, it is also necessary to set the angle between the axis of the shaft core and the axis of the long gear shaft between 5° and 90°. Through the dental contra-angle handpiece provided by this embodiment, only a certain angle needs to be set at the handpiece, and other positions are straight without bending, which can enable doctors to obtain a larger working space and visual field when performing root canal treatment of posterior teeth, and reduce the difficulty of operation during root canal treatment of posterior teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 One of the structural schematic diagrams of a dental contra-angle handpiece provided in an embodiment of the present invention;

[0021] Figure 2 The second structural schematic diagram of the dental contra-angle handpiece provided in the embodiment of the present invention;

[0022] Figure 3 The third structural schematic diagram of the dental contra-angle handpiece provided in the embodiment of the present invention;

[0023] Figure 4 A schematic diagram of the structure of an eccentric shaft carrier provided in an embodiment of the present invention;

[0024] Figure 5 A schematic structural diagram of a fourth gear provided in an embodiment of the present invention.

[0025] Icons: 100-dental contra-angle handpiece; 110-cylindrical housing; 1102-annular groove; 112-long gear shaft; 1122-fourth gear; 1124-fixing portion; 1125-engaging portion; 1126-inner gear teeth; 1128-fifth gear; 113-eccentric gear shaft; 1132-second gear; 1134-third gear; 114-eccentric shaft carrier; 1142-eccentric hole; 1144-first positioning hole; 115-long shaft sleeve; 1152-annular protrusion; 116-tightening ring; 120-input gear box; 121-input gear shaft; 1212-first gear; 122-gear box housing; 1222-second positioning hole; 1224-positioning pin; 124-coupling; 130-handpiece; 132-movement gear; 134-shaft core; 136-working tip; 140-bearing. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the description of the present invention, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The embodiment of the present invention mainly provides a dental contra-angle handpiece 100 and an endodontic treatment instrument, which can enable doctors to obtain a larger working space and field of view when performing endodontic treatment of posterior teeth, thereby reducing the difficulty of operation during endodontic treatment of posterior teeth. The endodontic treatment instrument generally includes a control host, an operating handle and a contra-angle handpiece, the control host is connected to the operating handle, a driving motor is arranged in the operating handle, and when the contra-angle handpiece is connected to the operating handle, the driving motor can drive the contra-angle handpiece to work, so as to achieve the purpose of treatment.

[0031] Please refer to Figure 1 This embodiment provides a dental contra-angle handpiece 100, comprising a cylindrical housing 110, an input gear box 120 is disposed at the first end of the cylindrical housing 110, and a handpiece 130 is disposed at the second end of the cylindrical housing 110. The handpiece 130 is a part for inserting into the oral cavity to treat teeth. Figure 2 As shown, the input gear box 120 includes an input gear shaft 121, a long gear shaft 112 is arranged in the cylindrical housing 110, and the handpiece 130 includes a core gear 132 and a shaft core 134 fixedly connected to the core gear 132, and the shaft core 134 is used to insert a working tip 136, and different working tips 136 are selectively used according to the actual condition to perform treatment. The core gear 132 is connected to the input gear shaft 121 through the long gear shaft 112, and the axis of the long gear shaft 112 is in the same straight line as the axis of the input gear shaft 121, and the angle α between the axis of the shaft core 134 and the axis of the long gear shaft 112 is 5° to 90°.

[0032] It should be noted that, first, the cylindrical housing 110 provided in this embodiment refers to a rotating body obtained with the rotation axis as the center. In order to adapt to the oral cavity of the human body and to be properly connected with the handle, the diameter of the first end close to the input gear box 120 is larger, while the diameter of the second end close to the head 130 is relatively smaller. The first end and the second end of the cylindrical housing 110 may have a certain gradual change in diameter (such as Figure 1 As shown), the above structure ensures that the first end of the cylindrical shell 110 is normally connected to the handle, and also ensures that the diameter of the connection of the head 130 meets the requirements of use.

[0033] Second, the input gear shaft 121 is used to transmit torque. When the dental contra-angle handpiece 100 is connected to the operating handle through the input gear box 120, the torque obtained by the input gear shaft 121 is transmitted to the core gear 132 through the long gear shaft 112 that is transmission-connected to the input gear shaft 121. Since the core gear 132 is fixedly connected to the shaft core 134, the shaft core 134 rotates. In order to ensure the smooth rotation of the shaft core 134, the shaft core 134 and the core gear 132 need to be coaxially fixed. The shaft core 134 is used to install the working tip 136 to facilitate root canal treatment of teeth. The working tip 136 has various types, such as K-file, open file and channel file.

[0034] Third, the axis of the long gear shaft 112 and the axis of the input gear shaft 121 are on the same straight line, and the straight line can also be on the same line with the rotation center line of the cylindrical housing 110, so as to better utilize the space in the cylindrical housing 110 and maximize the field of view during use. In addition, the angle α between the axis of the shaft core 134 and the axis of the long gear shaft 112 is set to 5° to 90°, such as 5°, 30°, 60° or 90°. When the doctor holds the handle for operation, the handpiece 130 inserted into the oral cavity can have a suitable size for easy operation.

[0035] Fourth, the handpiece 130 includes a handpiece 130 housing, a movement gear 132 and a shaft core 134 are both disposed in the handpiece 130 housing, and the handpiece 130 housing and the cylindrical housing 110 can be formed in an integral manner or in a detachable manner, and can be arranged as required. Among them, when the integral manner is adopted, in order to facilitate the assembly of the parts inside the handpiece 130 housing, a detachable rear cover can be arranged on the side away from the working tip 136 to ensure smooth assembly.

[0036] The dental contra-angle handpiece 100 provided in the embodiment of the present invention, through the cylindrical housing 110, is convenient for doctors to better hold the dental contra-angle handpiece 100, and at the same time obtain a better viewing angle and operating space. Through the input gear box 120 arranged at the first end of the cylindrical housing 110 and the handpiece 130 arranged at the second end of the cylindrical housing 110, as well as the input gear shaft 121 of the input gear box 120 and the core gear 132 of the handpiece 130, the core gear 132 can be connected to the input gear shaft 121 through the long gear shaft 112 arranged in the cylindrical housing 110. In order to ensure the stability of the transmission connection and the lateral size of the cylindrical housing 110 is not increased, so as not to affect the normal viewing angle, it is also necessary to ensure that the axis of the long gear shaft 112 and the axis of the input gear shaft 121 are on the same straight line to ensure the lateral size of the cylindrical housing 110. In addition, when the dental contra-angle handpiece 100 is used normally, in order to ensure that the angle adapts to the space of the oral cavity, it is also necessary to set the angle between the axis of the shaft core 134 and the axis of the long gear shaft 112 to be between 5° and 90°. With the dental contra-angle handpiece 100 provided in this embodiment, only a certain angle needs to be set at the handpiece head 130, and other positions are straight without the need for further bending, which enables the doctor to obtain a larger working space and field of view when performing root canal treatment of the posterior teeth, thereby reducing the difficulty of operation during root canal treatment of the posterior teeth.

[0037] Alternatively, if Figure 2 and Figure 4As shown, an eccentric gear shaft 113 and an eccentric shaft carrier 114 are also provided in the cylindrical housing 110 . The eccentric shaft carrier 114 is axially penetrated with an eccentric hole 1142 . The eccentric gear shaft 113 is arranged through the eccentric hole 1142 . The axis of the eccentric gear shaft 113 is parallel to the axis of the long gear shaft 112 .

[0038] Specifically, the eccentric gear shaft 113 is located between the long gear shaft 112 and the input gear shaft 121, and is used to establish a corresponding connection relationship between the long gear shaft 112 and the input gear shaft 121. The eccentric shaft carrier 114 is correspondingly arranged with the eccentric gear shaft 113, so that the eccentric gear shaft 113 can be stably transmitted. Since the axis of the long gear shaft 112 and the axis of the input gear shaft 121 are on the same straight line, when the eccentric gear shaft 113 is used for transmission, it is necessary to set an eccentric hole 1142 of a suitable size on the eccentric shaft carrier 114, and the position and size of the eccentric hole 1142 can be flexibly set according to actual needs. By setting the axis of the eccentric gear shaft 113 and the axis of the long gear shaft 112 to be parallel, it is convenient to make the various transmission components in the cylindrical housing 110 more compact, the space utilization rate is higher, and the viewing angle during operation is further increased.

[0039] Optionally, a first gear 1212 is provided at one end of the input gear shaft 121, a second gear 1132 and a third gear 1134 are provided at both ends of the eccentric gear shaft 113, a fourth gear 1122 is provided at one end of the long gear shaft 112 close to the eccentric gear shaft 113, the first gear 1212 and the second gear 1132 are externally meshed, and the third gear 1134 and the fourth gear 1122 are internally meshed. A fourth gear 1122 is provided at one end of the long gear shaft 112 close to the eccentric gear shaft 113, a fifth gear 1128 is provided at one end of the long gear shaft 112 away from the eccentric gear shaft 113, and the fifth gear 1128 is meshed with a movement gear 132, and the movement gear 132 is located at a side away from the axis of the long gear shaft 112 and away from the shaft core 134 inserted into the working tip 136.

[0040] Specifically, a first gear 1212 is provided at one end of the input gear shaft 121 close to the eccentric gear shaft 113. The first gear 1212 and the input gear shaft 121 can be integrally formed, or a detachable gear can be used. The second gear 1132 and the third gear 1134 at both ends of the eccentric gear shaft 113 can be integrally formed. For example, when the second gear 1132 and the eccentric gear shaft 113 are integrally formed, the third gear 1134 and the eccentric gear shaft 113 can be detachably connected. In this way, it is possible to avoid the impact of the assembly between the eccentric gear shaft 113 and the eccentric shaft carrier 114 due to the conflict between the size of the second gear 1132 and the third gear 1134 and the size of the eccentric hole 1142.

[0041] Similarly, the fourth gear 1122 and the fifth gear 1128 at both ends of the long gear shaft 112 can be selected to be in the form of integral molding. For example, when the fourth gear 1122 and the eccentric gear shaft 113 are integrally molded, the fifth gear 1128 and the long gear shaft 112 can be detachably connected to avoid affecting normal assembly. In the cooperation between the second gear 1132 and the third gear 1134 and the eccentric gear shaft 113, and the cooperation between the fourth gear 1122 and the fifth gear 1128 and the long gear shaft 112, the second gear 1132 and the fifth gear 1128 are preferably integrally molded, and the third gear 1134 and the fourth gear 1122 are preferably in a detachable form.

[0042] The eccentric hole 1142 of the eccentric shaft carrier 114 allows a certain eccentricity between the input gear shaft 121 and the eccentric gear shaft 113, so that the first gear 1212 and the second gear 1132 can both be in an external meshing form. At the same time, in order to ensure that the final transmission ratio and steering meet the requirements, the third gear 1134 and the fourth gear 1122 can be set to an internal meshing form, and the pitch circle diameter of the third gear 1134 is smaller than the pitch circle diameter of the fourth gear 1122.

[0043] Also, please refer to Figure 2 , the movement gear 132 is located at a side that deviates from the axis of the long gear shaft 112 and is far away from the side where the shaft core 134 is inserted into the working tip 136, that is, the movement gear 132 is set above the axis of the long gear shaft 112. In this way, the positional relationship between the components in the handpiece 130 can be better adjusted, making the components in the handpiece 130 more compact, avoiding the lateral space of the handpiece 130 being wider when the movement gear 132 is located on the axis of the long gear shaft 112, and avoiding the components in the handpiece 130 being too dispersed when the movement gear 132 is located on the same side as the shaft core 134 inserting the working tip 136, thereby affecting the compactness of the components in the handpiece 130. By adopting the above method, the handpiece 130 can be made more miniaturized, so that it occupies less space when entering the oral cavity, and it is also beneficial for doctors to have a better viewing angle and operating space.

[0044] Alternatively, if Figure 3 As shown, a long shaft sleeve 115 and a tightening ring 116 are further provided in the cylindrical shell 110, an annular groove 1102 is provided on the inner wall of the cylindrical shell 110, and an annular protrusion 1152 is correspondingly provided on the long shaft sleeve 115, and the annular protrusion 1152 abuts against the annular groove 1102. The input gear box 120 also includes a gear box shell 122 connected to the first end of the cylindrical shell 110, and the long shaft sleeve 115, the tightening ring 116, the eccentric shaft carrier 114 and the gear box shell 122 abut against each other in sequence.

[0045] Specifically, the long gear shaft 112 is disposed through the long shaft sleeve 115, and the long shaft sleeve 115 provides a stable support for the transmission of the long gear shaft 112. The long shaft sleeve 115 and the eccentric shaft carrier 114 can be axially positioned by the annular groove 1102 disposed on the inner wall of the cylindrical housing 110 matching with the annular protrusion 1152 disposed correspondingly on the long shaft sleeve 115, and the long shaft sleeve 115, the tightening ring 116, the eccentric shaft carrier 114 and the gear box housing 122 abutting in sequence.

[0046] A groove may be further provided at the annular groove 1102 on the inner wall of the cylindrical shell, and a protrusion may be further provided on the outer wall of the annular protrusion 1152 of the long shaft sleeve 115. When the annular groove 1102 and the annular protrusion 1152 are matched in a specific orientation, the groove provided at the annular groove 1102 can be snap-fitted with the protrusion provided on the outer wall of the annular protrusion 1152, thereby limiting the radial direction of the long shaft sleeve 115 and preventing the long shaft sleeve 115 from rotating under force.

[0047] Alternatively, if Figure 3 As shown, a first positioning hole 1144 is provided on the side of the eccentric shaft carrier 114 facing the input gear box 120 , and a second positioning hole 1222 is correspondingly provided on the side of the gear box housing 122 facing the eccentric shaft carrier 114 . The first positioning hole 1144 and the second positioning hole 1222 are positioned by a positioning pin 1224 .

[0048] Specifically, when the input gear box 120 is arranged at the first end of the cylindrical shell 110, the gear box shell 122 is connected and fixed to the cylindrical shell 110. At this time, a first positioning hole 1144 is provided on the side of the eccentric shaft carrier 114 facing the input gear box 120, and a second positioning hole 1222 is correspondingly provided on the side of the gear box shell 122 facing the eccentric shaft carrier 114, as well as a positioning pin 1224 respectively penetrated through the first positioning hole 1144 and the second positioning hole 1222, which can radially limit the eccentric shaft carrier 114 to prevent the eccentric shaft carrier 114 from rotating under force.

[0049] Alternatively, if Figure 3 As shown, bearings 140 are arranged in pairs in the long shaft sleeve 115, the eccentric shaft carrier 114 and the gear box housing 122, respectively. The bearings 140 are respectively located between the long shaft sleeve 115 and the long gear shaft 112, between the eccentric shaft carrier 114 and the eccentric gear shaft 113, and between the gear box housing 122 and the input gear shaft 121.

[0050] Specifically, for the bearing 140 between the long shaft sleeve 115 and the long gear shaft 112, the outer ring of the bearing 140 cooperates with the inner ring of the long shaft sleeve 115, and the inner ring of the bearing 140 cooperates with the long gear shaft 112. The two bearings 140 are separated from each other and distributed at both ends of the long gear shaft 112 to ensure the stability and coaxiality of the long gear shaft 112 when rotating, which is also conducive to extending the service life of the long gear shaft 112. Similarly, the gear between the eccentric shaft carrier 114 and the eccentric gear shaft 113, and the gear between the gear box housing 122 and the input gear shaft 121 are similar to the arrangement of the bearing 140 between the long shaft sleeve 115 and the long gear shaft 112, and will not be repeated here. After the bearing 140 is installed, axial movement may occur during movement. Conventional methods can be used to limit the bearing 140, such as setting a protrusion at the corresponding position of the eccentric hole 1142 or the inner ring of the gear box housing 122, or using a retaining spring or the like to fix and limit.

[0051] Alternatively, if Figure 5 As shown, the fourth gear 1122 includes a fixing portion 1124 and a meshing portion 1125 which are connected to each other. The fixing portion 1124 is used to be fixedly connected to the long gear shaft 112 , and the meshing portion 1125 is provided with internal gear teeth 1126 for meshing with the third gear 1134 .

[0052] Specifically, the outer gear teeth of the third gear 1134 mesh with the inner gear teeth 1126 on one side of the fourth gear 1122 for transmission. Due to factors such as machining errors, axial interference may occur when the third gear 1134 meshes with the fourth gear 1122 for transmission. At this time, the assembly depth between the fixing portion 1124 and the long gear shaft 112 can be adjusted to ensure the stability of the meshing portion.

[0053] Alternatively, if Figure 2 As shown, a coupling 124 is provided at one end of the input gear shaft 121 away from the first gear 1212, and the coupling 124 is used for transmission connection with the drive motor. In this way, the transmission matching form can be simplified, which is conducive to improving the stability and simplicity of matching. When in use, the required transmission can be achieved directly through the matching of the coupling 124.

[0054] The dental contra-angle handpiece 100 provided by the embodiment of the present invention works as follows: when in use, the first end of the cylindrical housing 110 of the dental contra-angle handpiece 100 is connected to the operating handle. Since the first end of the cylindrical housing 110 is provided with an input gear box 120, the input gear shaft 121 in the input gear box 120 establishes a transmission connection relationship with the driving motor in the operating handle through the coupling 124. The input gear shaft 121 then meshes with the second gear 1132 on one end of the eccentric gear shaft 113 through the first gear 1212, and the third gear 1134 on the other end of the eccentric gear shaft 113 rotates synchronously. When the third gear 1134 rotates, since the fourth gear 1122 on one end of the long gear shaft 112 meshes with the third gear 1134, the fifth gear 1128 rotates synchronously with the fourth gear 1122, and the fourth gear 1122 then drives the core gear 132 of the handpiece 130 to rotate. Since the core gear 132 is coaxially fixed with the shaft core 134, the shaft core 134 is driven to rotate, and the working tip 136 can be put into operation by loading the working tip 136 on the shaft core 134. During the transmission process, the first transmission ratio between the first gear 1212 and the second gear 1132 and the second transmission ratio between the third gear 1134 and the fourth gear 1122 are experienced, and the third transmission ratio between the fifth gear 1128 and the core gear 132 can also be selectively increased, so that the final output speed and rotation direction meet actual needs.

[0055] The embodiment of the present invention further discloses an endodontic treatment instrument, comprising the dental contra-angle handpiece 100 of the aforementioned embodiment and a handle connected to the dental contra-angle handpiece 100. The endodontic treatment instrument comprises the same structure and beneficial effects as the dental contra-angle handpiece 100 of the aforementioned embodiment. The structure and beneficial effects of the dental contra-angle handpiece 100 have been described in detail in the aforementioned embodiment, and will not be repeated here.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dental contra-angle handpiece, characterized in that: It comprises a cylindrical shell, an input gear box is arranged at the first end of the cylindrical shell, a machine head is arranged at the second end of the cylindrical shell, the input gear box comprises an input gear shaft, a long gear shaft is arranged in the cylindrical shell, the machine head comprises a movement gear and an axis core fixedly connected to the movement gear, the axis core is used to insert a working tip, the movement gear is connected to the input gear shaft through the long gear shaft, the axis of the long gear shaft is in the same straight line with the axis of the input gear shaft, and the angle between the axis of the axis core and the axis of the long gear shaft is 5° to 90°; An eccentric gear shaft and an eccentric shaft carrier are also provided in the cylindrical shell, the eccentric shaft carrier is provided with an eccentric hole along the axial direction, the eccentric gear shaft is arranged through the eccentric hole, the axis of the eccentric gear shaft is parallel to the axis of the long gear shaft, a long shaft sleeve and a tightening ring are also provided in the cylindrical shell, an annular groove is provided on the inner wall of the cylindrical shell, the long shaft sleeve is correspondingly provided with an annular protrusion, the annular protrusion abuts against the annular groove, the input gear box also includes a gear box shell connected to the first end of the cylindrical shell, the long shaft sleeve, the tightening ring, the eccentric shaft carrier and the gear box shell abut in sequence, a first positioning hole is provided on the side of the eccentric shaft carrier facing the input gear box, and a second positioning hole is correspondingly provided on the side of the gear box shell facing the eccentric shaft carrier, and the first positioning hole and the second positioning hole are positioned by a positioning pin; A first gear is provided at one end of the input gear shaft, a second gear and a third gear are respectively provided at both ends of the eccentric gear shaft, a fourth gear is provided at one end of the long gear shaft close to the eccentric gear shaft, the first gear is externally meshed with the second gear, the third gear is internally meshed with the fourth gear, the fourth gear includes a fixing portion and a meshing portion connected to each other, the fixing portion is used for fixedly connecting with the long gear shaft, and the meshing portion is provided with internal gear teeth for meshing with the third gear.

2. The dental contra-angle handpiece according to claim 1, characterized in that: A fifth gear is arranged at one end of the long gear shaft away from the eccentric gear shaft, and the fifth gear meshes with the movement gear. The movement gear is located away from the axis of the long gear shaft and away from the shaft core and inserted into the side of the working tip.

3. The dental contra-angle handpiece according to claim 1, characterized in that: The long shaft sleeve, the eccentric shaft carrier and the gear box housing are respectively provided with bearings in pairs, and the bearings are respectively located between the long shaft sleeve and the long gear shaft, between the eccentric shaft carrier and the eccentric gear shaft, and between the gear box housing and the input gear shaft.

4. The dental contra-angle handpiece according to claim 2, characterized in that: A coupling is provided at one end of the input gear shaft away from the first gear, and the coupling is used for transmission connection with the driving motor.

5. A root canal treatment apparatus, characterized in that: The invention comprises the dental contra-angle handpiece according to any one of claims 1 to 4 and a handle connected to the dental contra-angle handpiece.

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