阅读说明：本技术 一种牙科弯手机及根管治疗仪 (Dental curette and root canal therapy appearance ) 是由 黄永朝 吴坤优 陆友 刁跃虎 鲁成旺 于 2020-04-13 设计创作，主要内容包括：本发明公开了一种牙科弯手机及根管治疗仪,涉及口腔医疗器械技术领域。包括柱形壳体,该柱形壳体的第一端设置有输入齿轮箱,该柱形壳体的第二端设置有机头,输入齿轮箱包括输入齿轮轴,柱形壳体内设置有长齿轮轴,机头包括机芯齿轮以及与机芯齿轮固定连接的轴芯,机芯齿轮通过长齿轮轴与输入齿轮轴传动连接,长齿轮轴的轴线与输入齿轮轴的轴线在同一直线上,轴芯的轴线与长齿轮轴的轴线之间的夹角为5°至90°。能够使医生在进行后牙的根管治疗时获得更大工作空间和视野,降低后牙根管治疗时的操作难度。(The invention discloses a dental curette and a root canal therapeutic apparatus, and relates to the technical field of oral medical instruments. The cylindrical shell is provided with an input gear box at a first end, a machine head is arranged at a second end and comprises an input gear shaft, a long gear shaft is arranged in the cylindrical shell, the machine head comprises a machine core gear and a shaft core fixedly connected with the machine core gear, the machine core gear is in transmission connection with the input gear shaft through the long gear shaft, the axis of the long gear shaft and the axis of the input gear shaft are on the same straight line, and an included angle between the axis of the shaft core and the axis of the long gear shaft is 5-90 degrees. The utility model can make the doctor obtain larger working space and visual field when the root canal therapy of the posterior teeth is carried out, and reduce the operation difficulty when the root canal therapy of the posterior teeth is carried out.)

1. The utility model provides a dental bending handpiece, its characterized in that, includes the cylindricality casing, the first end of cylindricality casing is provided with the input gear box, the second end of cylindricality casing is provided with the aircraft nose, the input gear box includes the input gear axle, be provided with the long gear axle in the cylindricality casing, the aircraft nose include core gear and with core gear fixed connection's axle core, the axle core is used for inserting the work point, the core gear passes through the long gear axle with input gear axle transmission is connected, the axis of long gear axle with the axis of input gear axle is on same straight line, the axis of axle core with contained angle between the axis of long gear axle is 5 to 90.

2. The dental bender according to claim 1, wherein an eccentric gear shaft and an eccentric shaft carrier are further provided in the cylindrical housing, the eccentric shaft carrier having an eccentric hole provided therethrough in an axial direction, the eccentric gear shaft being provided through the eccentric hole, an axis of the eccentric gear shaft being parallel to an axis of the long gear shaft.

3. The dental bender according to claim 2, wherein a first gear is provided at one end of said input gear shaft, a second gear and a third gear are provided at both ends of said eccentric gear shaft, respectively, and a fourth gear is provided at an end of said elongated gear shaft adjacent to said eccentric gear shaft, said first gear and said second gear being externally engaged, and said third gear and said fourth gear being internally engaged.

4. The dental bender as claimed in claim 2 or 3, wherein a long shaft sleeve and a tightening ring are further provided in the cylindrical housing, an annular groove is provided in the inner wall of the cylindrical housing, an annular protrusion is correspondingly provided on the long shaft sleeve, the annular protrusion abuts against the annular groove, the input gearbox further comprises a gearbox housing connected to the first end of the cylindrical housing, and the long shaft sleeve, the tightening ring, the eccentric shaft carrier and the gearbox housing abut against one another in sequence.

5. Dental bending handpiece according to claim 2 or 3, wherein the end of the elongated gear shaft remote from the eccentric gear shaft is provided with a fifth gear, which meshes with the movement gear, which is located offset from the axis of the elongated gear shaft and remote from the side of the shaft core inserted into the tip.

6. The dental bender according to claim 4, wherein a side of said eccentric shaft carrier facing said input gearbox is provided with a first positioning hole, a side of said gearbox housing facing said eccentric shaft carrier is correspondingly provided with a second positioning hole, said first and second positioning holes are positioned by positioning pins.

7. Dental bender according to claim 4, characterized in that bearings are arranged in pairs in the long shaft sleeve, the eccentric shaft carrier and the gearbox housing, respectively, between the long shaft sleeve and the long gear shaft, between the eccentric shaft carrier and the eccentric gear shaft and between the gearbox housing and the input gear shaft, respectively.

8. Dental bender according to claim 3, characterized in that the fourth gear comprises a fixed part for fixed connection with the long gear shaft and an engaging part provided with inner gear teeth for engagement with the third gear, which parts are connected to each other.

9. A dental handpiece according to claim 3, wherein the end of said input gear shaft remote from said first gear is provided with a coupling for driving connection with a drive motor.

10. An endodontic instrument comprising the dental bender according to any of claims 1 to 9 and a handle connected to said dental bender.

Technical Field

The invention relates to the technical field of oral medical instruments, in particular to a dental curette and a root canal therapy instrument.

Background

Root canal therapy, also known as endodontic therapy, is an operation in dentistry to treat pulp necrosis and root infection. Root canal therapy is mainly directed to the interior of teeth, and is the most effective treatment method for treating acute pulpitis. The condition of the tooth is prevented from further worsening by removing necrotic tissue from within the pulp chamber and then refilling the pulp chamber after sterilization to relieve the pressure stimulation of the diseased tissue on the dental nerve.

When the root canal therapy is performed, in order to reduce the treatment time and relieve the pain of the patient, the root canal therapy is usually performed by means of a root canal therapy apparatus. In the current root canal instruments on the market, the dental bender forms an angle between the input shaft and the next transmission shaft, the shell must be designed to be large enough and have a certain angle at the corner of the form, and the final product has an angle at the nose and an angle at the connection part of the dental bender and the handle.

The arrangement form has too many bent angles, which is not convenient for a doctor to obtain larger working space and visual field during the root canal therapy, especially the root canal therapy of posterior teeth, and influences the operation of the doctor during the root canal therapy.

Disclosure of Invention

The invention aims to provide a dental bender and a root canal therapeutic apparatus, which can enable a doctor to obtain larger working space and visual field during the root canal therapy of posterior teeth and reduce the operation difficulty during the root canal therapy of the posterior teeth.

The embodiment of the invention is realized by the following steps:

in one aspect of the embodiment of the invention, a dental bending handpiece is provided, which comprises a cylindrical shell, wherein an input gear box is arranged at a first end of the cylindrical shell, a handpiece is arranged at a 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 handpiece comprises a core gear and a shaft core fixedly connected with the core gear, the shaft core is used for being inserted into a working tip, the core gear is in transmission connection with the input gear shaft through the long gear shaft, the axis of the long gear shaft and the axis of the input gear shaft are on the same straight line, and an included angle between the axis of the shaft core and the axis of the long gear shaft is 5-90 degrees.

Optionally, an eccentric gear shaft and an eccentric shaft carrier are further disposed in the cylindrical housing, an eccentric hole is axially formed in the eccentric shaft carrier in a penetrating manner, the eccentric gear shaft penetrates through the eccentric hole, an axis of the eccentric gear shaft is parallel to an axis of the long gear shaft, and the movement gear is located on one side, away from the eccentric gear shaft, of the axis of the long gear shaft.

Optionally, one end of the input gear shaft is provided with a first gear, two ends of the eccentric gear shaft are respectively provided with a second gear and a third gear, one end of the long gear shaft close to the eccentric gear shaft is provided with a fourth gear, the first gear is externally engaged with the second gear, and the third gear is internally engaged with the fourth gear.

Optionally, a long shaft sleeve and a jacking ring are further arranged in the cylindrical shell, an annular groove is formed in the inner wall of the cylindrical shell, an annular protrusion is correspondingly formed in the long shaft sleeve and abuts against the annular groove, the input gearbox further comprises a gearbox shell connected with the first end of the cylindrical shell, and the long shaft sleeve, the jacking ring, the eccentric shaft carrier and the gearbox shell abut against one another in sequence.

Optionally, one end of the long gear shaft, which is far away from the eccentric gear shaft, is provided with a fifth gear, the fifth gear is meshed with the movement gear, and the movement gear is located on one side, which is deviated from the axis of the long gear shaft and far away from the shaft core, and is inserted into the working tip.

Optionally, a first positioning hole is formed in one side, facing the input gearbox, of the eccentric shaft carrier, a second positioning hole is correspondingly formed in one side, facing the eccentric shaft carrier, of the gearbox housing, and the first positioning hole and the second positioning hole are positioned through positioning pins.

Optionally, bearings are provided in pairs in the long shaft sleeve, the eccentric shaft carrier and the gearbox housing, respectively, between the long shaft sleeve and the long gear shaft, between the eccentric shaft carrier and the eccentric gear shaft, and between the gearbox housing and the input gear shaft, respectively.

Optionally, the fourth gear comprises a fixing part and a meshing part which are connected with each other, the fixing part is used for being fixedly connected with the long gear shaft, and the meshing part is provided with inner gear teeth used for being meshed with the third gear.

Optionally, a coupling is arranged at one end of the input gear shaft far away from the first gear, and the coupling is used for being in transmission connection with a driving motor.

In another aspect of an embodiment of the present invention there is provided an endodontic instrument comprising a dental bender as claimed in any one of the above and a handpiece connected to said dental bender.

The embodiment of the invention has the beneficial effects that:

according to the dental curette and the root canal therapy instrument provided by the embodiment of the invention, through the cylindrical shell, a doctor can better hold the dental curette, and a better visual angle and an operation space can be obtained. Through the input gear box arranged at the first end of the cylindrical shell, the machine head arranged at the second end of the cylindrical shell, the input gear shaft of the input gear box and the machine core gear of the machine head, the machine core gear can be in transmission connection with the input gear shaft through the long gear shaft arranged in the cylindrical shell. In order to ensure the stability of transmission connection and the transverse size of the cylindrical shell is not increased so as to avoid influencing the normal visual angle, the axial line of the long gear shaft and the axial line of the input gear shaft are required to be on the same straight line so as to ensure the transverse size of the cylindrical shell. In addition, when the dental bending handpiece is normally used, in order to ensure the angle to be suitable for the space of the oral cavity, the included angle between the axis of the shaft core and the axis of the long gear shaft is required to be set between 5 degrees and 90 degrees. Through the dental curved hand piece that this embodiment provided, finally only need be provided with certain angle in aircraft nose department, other positions all are straight, need not to buckle again, can make the doctor obtain bigger workspace and field of vision when carrying out the root canal therapy of back tooth, the operation degree of difficulty when reducing back root canal therapy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of a dental handpiece according to an embodiment of the present invention;

FIG. 2 is a second schematic structural view of a dental bur according to an embodiment of the present invention;

FIG. 3 is a third schematic structural view of a dental handpiece according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an eccentric shaft carrier provided in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a fourth gear according to an embodiment of the present invention.

Icon: 100-dental handpieces; 110-a cylindrical housing; 1102-an annular groove; 112-long gear shaft; 1122-fourth gear; 1124-a fixed part; 1125-engaging portion; 1126-inner gear teeth; 1128-fifth gear; 113-eccentric gear shaft; 1132 — a second gear; 1134 — third gear; 114-eccentric shaft carrier; 1142-eccentric hole; 1144-first positioning hole; 115-long shaft sleeve; 1152-an annular projection; 116-a top-tightening ring; 120-input gearbox; 121-input gear shaft; 1212-first gear; 122-gearbox housing; 1222-a second positioning hole; 1224-locating pins; 124-coupling; 130-a handpiece; 132-movement gear; 134-an axial core; 136-a tip; 140-bearing.

Detailed Description

In order to make the objects, 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 with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. In the description of the present invention, the terms "first", "second", "third", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment of the invention mainly provides a dental bender 100 and a root canal therapeutic apparatus, which can enable a doctor to obtain larger working space and visual field during the root canal therapy of posterior teeth and reduce the operation difficulty during the root canal therapy of the posterior teeth. The endodontic instrument generally comprises a control host, an operating handle and a bending machine, wherein the control host is connected with the operating handle, a driving motor is arranged in the operating handle, and after the bending machine is connected with the operating handle, the bending machine can be driven to work by the driving motor so as to achieve the purpose of treatment.

Referring to fig. 1, the present embodiment provides a dental bender 100, including a cylindrical housing 110, an input gear box 120 is disposed at a first end of the cylindrical housing 110, a handpiece 130 is disposed at a second end of the cylindrical housing 110, the handpiece 130 is a part for extending into an oral cavity to treat teeth, as shown in fig. 2, the input gear box 120 includes an input gear shaft 121, a long gear shaft 112 is disposed in the cylindrical housing 110, the handpiece 130 includes a core gear 132 and a core 134 fixedly connected to the core gear 132, the core 134 is used for inserting a working tip 136, and different working tips 136 are selectively used according to actual conditions to perform treatment, the core gear 132 is in transmission connection with the input gear shaft 121 through the long gear shaft 112, an axis of the long gear shaft 112 and an axis of the input gear shaft 121 are on the same straight line, and an included angle α between the axis of the core 134 and the axis of the long gear shaft 112 is 5 ° to 90 °.

It should be noted that, first, the cylindrical housing 110 provided in this embodiment refers to a rotating body with a rotation axis as the center, and in order to adapt to the oral cavity of the human body and to be connected with the handle normally, the diameter is larger at the first end near the input gear box 120, and is smaller at the second end near the handpiece 130. The first end and the second end of the cylindrical housing 110 may have a gradual change in diameter (as shown in fig. 1), and the adoption of the above structure ensures that the first end of the cylindrical housing 110 is normally connected with the handle, and the diameter of the joint of the handpiece 130 meets the use requirement.

Secondly, the input gear shaft 121 is used to transmit torque, and after the dental bender 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 movement gear 132 through the long gear shaft 112 which is in driving connection with the input gear shaft 121. The movement gear 132 is fixedly connected with the shaft core 134, so that the shaft core 134 rotates. In order to ensure the smooth rotation of the shaft core 134, the shaft core 134 and the movement gear 132 need to be coaxially fixed. The mandrel 134 is used to mount a tip 136 to facilitate endodontic treatment of a tooth. The working tip 136 is of various types such as K-files, open files and channel files.

Third, the axis of the long gear shaft 112 is aligned with the axis of the input gear shaft 121, and the line can be aligned with the rotation center line of the cylindrical housing 110 to better utilize the space in the cylindrical housing 110 and maximize the visual field during use, and in addition, the included angle α between the axis of the shaft core 134 and the axis of the long gear shaft 112 is set to be 5 ° to 90 °, such as 5 °, 30 °, 60 ° or 90 °, etc.

Fourthly, the machine head 130 includes a machine head 130 casing, the core gear 132 and the shaft core 134 are both arranged in the machine head 130 casing, and the machine head 130 casing and the cylindrical shell 110 may be integrally formed or detachable, and may be arranged as required. Wherein, when adopting integrated into one piece, for the assembly of the convenience aircraft nose 130 shell inner part, can set up in the one side that deviates from work point 136 and dismantle the back lid to guarantee going on smoothly of assembly.

The dental bender 100 provided by the embodiment of the present invention is convenient for the doctor to better hold the dental bender 100 through the cylindrical housing 110, and simultaneously obtains a better viewing angle and an operation space. The input gear box 120 arranged at the first end of the cylindrical shell 110, the machine head 130 arranged at the second end of the cylindrical shell 110, the input gear shaft 121 of the input gear box 120 and the core gear 132 of the machine head 130 enable the core gear 132 to be in transmission connection with the input gear shaft 121 through the long gear shaft 112 arranged in the cylindrical shell 110. In order to ensure the stability of the transmission connection and the lateral dimension of the cylindrical housing 110 is not increased so as not to affect the normal viewing angle, it is also required to ensure that the axis of the long gear shaft 112 is aligned with the axis of the input gear shaft 121 so as to ensure the lateral dimension of the cylindrical housing 110. In addition, in order to ensure the angle to fit the space of the oral cavity when the dental bender 100 is in normal use, the angle between the axis of the shaft core 134 and the axis of the long gear shaft 112 is set to be between 5 ° and 90 °. Through the dental bender 100 that this embodiment provided, finally only need be provided with certain angle in aircraft nose 130 department, other positions are all straight, need not to buckle again, can make the doctor obtain bigger workspace and field of vision when carrying out the root canal therapy of back tooth, reduce the operation degree of difficulty when back root canal therapy.

Alternatively, as shown in fig. 2 and 4, an eccentric gear shaft 113 and an eccentric shaft carrier 114 are further disposed in the cylindrical housing 110, the eccentric shaft carrier 114 is axially and penetratingly disposed with an eccentric hole 1142, the eccentric gear shaft 113 is disposed through the eccentric hole 1142, and an axis of the eccentric gear shaft 113 is parallel to an axis of the long gear shaft 112.

Specifically, the eccentric gear shaft 113 is located between the long gear shaft 112 and the input gear shaft 121 for establishing a corresponding connection relationship between the long gear shaft 112 and the input gear shaft 121, and the eccentric shaft carrier 114 is disposed corresponding to the eccentric gear shaft 113, so that the eccentric gear shaft 113 can stably transmit power. Since the axis of the long gear shaft 112 is on the same straight line with the axis of the input gear shaft 121, when the transmission is performed through the eccentric gear shaft 113, an eccentric hole 1142 with a suitable size needs to be formed in 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 space utilization ratio between the transmission parts in the cylindrical housing 110 more compact, and further increase the viewing angle in operation.

Alternatively, one end of the input gear shaft 121 is provided with a first gear 1212, both ends of the eccentric gear shaft 113 are provided with a second gear 1132 and a third gear 1134, respectively, one end of the long gear shaft 112 near the eccentric gear shaft 113 is provided with a fourth gear 1122, the first gear 1212 and the second gear 1132 are externally engaged, and the third gear 1134 and the fourth gear 1122 are internally engaged. One end of the long gear shaft 112 close to the eccentric gear shaft 113 is provided with a fourth gear 1122, one end of the long gear shaft 112 far from the eccentric gear shaft 113 is provided with a fifth gear 1128, the fifth gear 1128 is meshed with the movement gear 132, and the movement gear 132 is positioned at a position deviated from the axis of the long gear shaft 112 and far from the side of the shaft core 134 inserted into the work tip 136.

Specifically, one end of the input gear shaft 121 close to the eccentric gear shaft 113 is provided with a first gear 1212, and the first gear 1212 and the input gear shaft 121 may be integrally formed or may be a detachable gear. The second gear 1132 and the third gear 1134 at two ends of the eccentric gear shaft 113 may alternatively 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 may be detachably connected. Thus, it is possible to avoid the interference between the eccentric gear shaft 113 and the eccentric shaft carrier 114 due to the size of the second gear 1132 and the third gear 1134 colliding with the size of the eccentric hole 1142.

Similarly, the fourth gear 1122 and the fifth gear 1128 at the two ends of the long gear shaft 112 may alternatively be integrally formed, for example, when the fourth gear 1122 and the eccentric gear shaft 113 are integrally formed, the fifth gear 1128 and the long gear shaft 112 may be detachably connected to each other so as not to interfere with the normal assembly. In the fitting of the second gear 1132 and the third gear 1134 to the eccentric gear shaft 113 and the fitting of the fourth gear 1122 and the fifth gear 1128 to the long gear shaft 112, the second gear 1132 and the fifth gear 1128 are preferably integrally formed, and the third gear 1134 and the fourth gear 1122 are preferably detachable.

The eccentric hole 1142 of the eccentric shaft carrier 114 allows an eccentricity between the input gear shaft 121 and the eccentric gear shaft 113, and thus, both the first gear 1212 and the second gear 1132 may adopt an external engagement form. Meanwhile, in order to ensure that the final gear ratio and the steering are satisfied, the third gear 1134 and the fourth gear 1122 can be arranged in an internal meshing manner, and the pitch circle diameter of the third gear 1134 is smaller than that of the fourth gear 1122.

In addition, referring to fig. 2, the movement gear 132 is located at a position offset from the axis of the long gear shaft 112 and away from the side of the shaft core 134 inserted into the working tip 136, i.e. the movement gear 132 is disposed above the axis of the long gear shaft 112. Therefore, the position relation among the components in the machine head 130 can be better adjusted, so that the components in the machine head 130 are more compact, the situation that the transverse space of the machine head 130 is wider when the core gear 132 is positioned on the axis of the long gear shaft 112 is avoided, and the situation that the components in the machine head 130 are too dispersed when the core gear 132 is positioned on the same side with the shaft core 134 inserted into the working tip 136, and the compactness of the components in the machine head 130 is influenced, are also avoided. By adopting the mode, the handpiece 130 can be more miniaturized, so that the occupied space is smaller when the handpiece goes deep into the oral cavity, and a doctor can have a better visual angle and an operation space.

Optionally, as shown in fig. 3, a long shaft sleeve 115 and a tightening ring 116 are further disposed in the cylindrical housing 110, an annular groove 1102 is disposed on the inner wall of the cylindrical housing 110, an annular protrusion 1152 is correspondingly disposed on the long shaft sleeve 115, the annular protrusion 1152 abuts against the annular groove 1102, the input gearbox 120 further includes a gearbox housing 122 connected to the first end of the cylindrical housing 110, and the long shaft sleeve 115, the tightening ring 116, the eccentric shaft carrier 114, and the gearbox housing 122 sequentially abut against each other.

Specifically, the long gear shaft 112 passes through the long shaft sleeve 115, and the long shaft sleeve 115 provides a stable supporting function 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 matching the annular groove 1102 arranged on the inner wall of the cylindrical shell 110 with the annular protrusion 1152 correspondingly arranged on the long shaft sleeve 115 and sequentially abutting the long shaft sleeve 115, the jacking ring 116, the eccentric shaft carrier 114 and the gear box shell 122.

The annular groove 1102 on the inner wall of the cylindrical shell can be provided with a groove, the outer wall of the annular bulge 1152 of the long shaft sleeve 115 can be provided with a bulge, and when the annular groove 1102 and the annular bulge 1152 are matched in a specific direction, the groove formed in the annular groove 1102 can be matched with the bulge arranged on the outer wall of the annular bulge 1152 in a clamping mode, so that the radial direction of the long shaft sleeve 115 is limited, and the long shaft sleeve 115 is prevented from rotating under stress.

Alternatively, as shown in fig. 3, the side of the eccentric shaft carrier 114 facing the input gearbox 120 is provided with a first positioning hole 1144, the side of the gearbox housing 122 facing the eccentric shaft carrier 114 is correspondingly provided with a second positioning hole 1222, and the first positioning hole 1144 and the second positioning hole 1222 are positioned by the positioning pin 1224.

Specifically, when the input gearbox 120 is disposed at the first end of the cylindrical housing 110, the gearbox housing 122 is fixedly connected to the cylindrical housing 110, and at this time, a first positioning hole 1144 is disposed through one side of the eccentric shaft carrier 114 facing the input gearbox 120, a second positioning hole 1222 is correspondingly disposed through one side of the gearbox housing 122 facing the eccentric shaft carrier 114, and positioning pins 1224 respectively inserted into the first positioning hole 1144 and the second positioning hole 1222 are capable of radially limiting the eccentric shaft carrier 114, so as to prevent the eccentric shaft carrier 114 from being rotated by force.

Alternatively, as shown in fig. 3, bearings 140 are provided in pairs in the long bushing 115, the eccentric shaft carrier 114 and the gear case housing 122, respectively, the bearings 140 being located between the long bushing 115 and the long gear shaft 112, between the eccentric shaft carrier 114 and the eccentric gear shaft 113, and between the gear case housing 122 and the input gear shaft 121, respectively.

Specifically, for the bearing 140 between the long shaft sleeve 115 and the long gear shaft 112, the outer ring of the bearing 140 is matched with the inner ring of the long shaft sleeve 115, the inner ring of the bearing 140 is matched with the long gear shaft 112, and the two bearings 140 are far away from each other and distributed at two ends of the long gear shaft 112, so as to ensure the stability and the coaxiality of the long gear shaft 112 during rotation and also facilitate prolonging the service life of the long gear shaft 112. Similarly, the gears between the eccentric shaft carrier 114 and the eccentric gear shaft 113, and the gears between the gear housing 122 and the input gear shaft 121 are similar to the arrangement of the bearings 140 between the long shaft sleeve 115 and the long gear shaft 112, and thus, detailed description thereof is omitted. After the bearing 140 is installed, axial play may occur during movement, and the bearing 140 may be limited by a conventional method, for example, a protrusion is disposed at a corresponding position of the eccentric hole 1142 or the inner ring of the gear case housing 122, or fixed and limited by a form such as a snap spring.

Alternatively, as shown in fig. 5, the fourth gear 1122 includes a fixing portion 1124 and a meshing portion 1125 connected to each other, the fixing portion 1124 being for fixing connection with the long gear shaft 112, and the meshing portion 1125 being provided with inner gear teeth 1126 for meshing with the third gear 1134.

Specifically, the external teeth of the third gear 1134 are engaged with the internal teeth 1126 on the side of the fourth gear 1122, and due to machining errors and other factors, axial interference may occur when the third gear 1134 is engaged with the fourth gear 1122, and at this time, the assembly depth between the fixing portion 1124 and the long gear shaft 112 may be adjusted to ensure the stability of the engagement.

Optionally, as shown in fig. 2, an end of the input gear shaft 121 remote from the first gear 1212 is provided with a coupling 124, and the coupling 124 is used for being in transmission connection with a driving motor. Therefore, the transmission matching form can be simplified, the stability and the simplicity of matching are improved, and the required transmission can be realized by directly matching the coupling 124 during use.

The dental bur 100 provided by the embodiment of the present invention has the following working process: when in use, the first end of the cylindrical shell 110 of the dental bender 100 is connected with the operating handle, and the input gear box 120 is arranged at the first end of the cylindrical shell 110, so that the input gear shaft 121 in the input gear box 120 is in transmission connection with the driving motor in the operating handle through the coupling 124. The input gear shaft 121 is further in meshing transmission with the second gear 1132 at one end of the eccentric gear shaft 113 through the first gear 1212, the third gear 1134 at the other end of the eccentric gear shaft 113 rotates synchronously, when the third gear 1134 rotates, the fourth gear 1122 at one end of the long gear shaft 112 is meshed with the third gear 1134, so that the fifth gear 1128 and the fourth gear 1122 rotate synchronously, and the fourth gear 1122 drives the movement gear 132 of the handpiece 130 to rotate. Because the movement gear 132 and the shaft core 134 are coaxially and fixedly arranged, the shaft core 134 is finally driven to rotate, and the working tip 136 can work by loading the working tip 136 on the shaft core 134. During the transmission, a first-stage transmission ratio between the first gear 1212 and the second gear 1132 and a second-stage transmission ratio between the third gear 1134 and the fourth gear 1122 are experienced, and a third-stage transmission ratio between the fifth gear 1128 and the movement gear 132 can also be selectively increased, so that the rotation speed and the rotation direction of the final output meet the actual requirements.

The embodiment of the invention also discloses an endodontic instrument which comprises the dental bender 100 of the previous embodiment and a handle connected with the dental bender 100. The endodontic instrument includes the same structure and advantageous effects as the dental bender 100 of the previous embodiment. The structure and advantages of the dental handpiece 100 have been described in detail in the foregoing embodiments and will not be described in detail herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.