CN220309172U - Medical grinding tool and inner tool assembly thereof - Google Patents

Abstract

The application relates to a medical grinding cutter and inner knife assembly thereof, the inner knife assembly of medical grinding cutter includes: the inner cutter head, the metal wire and the first heat shrinkage sleeve. One end of the metal wire is connected with the inner cutter head, the other end of the metal wire is connected with the transmission assembly, and the metal wire is provided with a bending part. The first heat shrinkage sleeve is sleeved outside the bending part. The inner cutter assembly of the medical grinding cutter is characterized in that the transmission assembly drives the metal wire to rotate when the inner cutter assembly works, the metal wire drives the inner cutter head to rotate, and the inner cutter head rotates to polish bone tissues. When fracture appears because of stress concentration in the bending part, owing to its outside cover is equipped with first pyrocondensation cover, can prevent that interior tool bit from dropping in internal to can improve work efficiency and security.

Description

Medical grinding tool and inner tool assembly thereof

Technical Field

The application relates to the technical field of medical instruments, in particular to a medical grinding cutter and an inner cutter assembly thereof.

Background

Medical grinding tools are commonly used in bone surgery to grind bone tissue in humans. Some medical grinding tools also have curved structures to accommodate more complex surgical sites such as ear, nose, throat, spine, etc. Existing medical grinding tools generally include an inner cutter assembly and an outer cutter assembly, the inner cutter assembly being rotatable relative to the outer cutter assembly along its own axis, and during rotation, being engaged with the outer cutter assembly for grinding. The inner cutter assembly generally comprises a bent inner cutter tube, an inner cutter head and a power interface, wherein the power interface is used for being connected with a motor and driven by the motor to rotate, so that the inner cutter tube is correspondingly driven to rotate, the bent part of the inner cutter tube can synchronously rotate and forward transmit torque to drive the inner cutter head to rotate, and grinding action is realized. However, the bending part of the inner cutter tube is concentrated in stress, and after a period of use, the inner cutter tube is easy to break. Once broken, the inner cutter head and the front section of the inner cutter tube are positioned in the body, so that a large amount of time is required to be consumed to take out the inner cutter head and the front section of the inner cutter tube from the body, and the working efficiency and the safety are low.

Disclosure of Invention

Based on this, it is necessary to overcome the defects of the prior art, and to provide a medical grinding tool and an inner tool assembly thereof, which can prevent an inner tool bit from falling into a body, thereby improving working efficiency and safety.

An inner blade assembly of a medical grinding tool, the inner blade assembly of the medical grinding tool comprising:

an inner cutter head;

one end of the metal wire is connected with the inner cutter head, the other end of the metal wire is connected with the transmission assembly, and the metal wire is provided with a bending part; and

the first heat shrinkage sleeve is sleeved outside the bending part.

In one embodiment, the inner cutter assembly of the medical grinding cutter further comprises a connecting sleeve; the inner cutter head comprises a grinding head and a rod part connected with the grinding head; the rod part extends into one end of the connecting sleeve and is connected with the connecting sleeve in a welding way, and the metal wire extends into the other end of the connecting sleeve and is connected with the connecting sleeve in a welding way.

In one embodiment, a first step is arranged on the outer wall of the rod part, and the end face of the connecting sleeve is mutually abutted with the first step; the inner wall of the connecting sleeve is provided with a second step, and the end face of the rod part is mutually abutted with the second step.

In one embodiment, the connecting sleeve is provided with at least one first welding hole extending along the axis of the connecting sleeve, and the first welding hole is opposite to the outer wall of the rod part; and the connecting sleeve is also provided with at least one second welding hole extending along the axis of the connecting sleeve, and the second welding hole is opposite to the outer wall of the metal wire.

The medical grinding tool comprises an inner tool assembly, an outer tool assembly and a transmission assembly, wherein the inner tool assembly is rotatably arranged in the outer tool assembly in a penetrating mode, the other end of the metal wire is connected with the transmission assembly, and the transmission assembly is used for being connected with a power mechanism.

In one embodiment, the outer cutter assembly comprises a handle body, an outer cutter tube and a first support sleeve; the handle body is provided with a channel, and the transmission assembly is rotatably arranged in the channel in a penetrating way; one end of the outer cutter tube is connected with the handle body, and the other end of the outer cutter tube is connected with the first supporting sleeve; the metal wire is rotatably arranged in the outer cutter tube in a penetrating mode, and the inner cutter head is rotatably arranged in the first supporting sleeve in a penetrating mode.

In one embodiment, the transmission assembly comprises a transmission shaft, a bearing rotatably arranged on the transmission shaft and a first limiting stop piece in mutual abutting fit with one end face of the bearing, a positioning flange in mutual abutting fit with the other end face of the bearing is arranged on the inner wall of the channel, and the first limiting stop piece is connected with the inner wall of the channel; the metal wire is fixedly connected with the transmission shaft, and the transmission shaft is also used for being connected with the power mechanism.

In one embodiment, the transmission assembly further comprises a first sealing ring disposed between the outer wall of the transmission shaft and the inner wall of the bearing, and a second sealing ring disposed between the outer wall of the bearing and the inner wall of the channel; the transmission shaft is provided with a shaft hole, and the metal wire penetrates through the shaft hole and is connected with the transmission shaft in a welding mode.

In one embodiment, the number of the bearings is at least two, and each bearing is sequentially sleeved on the transmission shaft along the axial direction of the transmission shaft.

In one embodiment, the outer cutter assembly further comprises a second support sleeve, the second support sleeve is connected with the handle body, and the outer cutter tube is arranged in the second support sleeve in a penetrating manner; the outer cutter tube is close to the outer wall of one end of the handle body, and is provided with at least one liquid discharge hole, and the liquid discharge hole is communicated with a liquid discharge channel between the inner wall of the outer cutter tube and the outer wall of the metal wire.

The medical grinding cutter and the inner cutter assembly thereof, when in work, the transmission assembly drives the metal wire to rotate, the metal wire drives the inner cutter head to rotate, and the inner cutter head realizes the grinding operation on bone tissues in the rotating process. When fracture appears because of stress concentration in the bending part, owing to its outside cover is equipped with first pyrocondensation cover, can prevent that interior tool bit from dropping in internal to can improve work efficiency and security.

Drawings

Fig. 1 is a schematic structural view of a medical grinding tool according to an embodiment of the present application.

Fig. 2 is an enlarged schematic view of the structure at a in fig. 1.

Fig. 3 is an enlarged schematic view of the structure of fig. 1 at B.

Fig. 4 is a schematic structural view of an inner cutter assembly of a medical grinding cutter according to an embodiment of the present application.

Fig. 5 is a schematic structural view of an outer cutter assembly of a medical grinding cutter according to an embodiment of the present application.

Fig. 6 is a schematic structural view of a transmission assembly of a medical grinding tool according to an embodiment of the present application.

Fig. 7 is a schematic structural view of a medical grinding tool according to another embodiment of the present application.

Fig. 8 is an enlarged schematic view of the structure of fig. 7 at C.

10. An inner cutter assembly; 11. an inner cutter head; 111. grinding head; 112. a stem portion; 1121. a first step; 12. a wire; 121. a bending portion; 13. a first heat shrink sleeve; 14. connecting sleeves; 141. a second step; 15. a second heat shrink sleeve; 20. an outer cutter assembly; 21. a handle body; 211. a channel; 2111. positioning the flange; 212. a split shell; 22. an outer cutter tube; 221. a liquid discharge hole; 23. a first support sleeve; 24. a second support sleeve; 25. an elastic layer; 26. a fixed sleeve; 27. a third support sleeve; 30. a transmission assembly; 31. a transmission shaft; 311. a shaft hole; 32. a bearing; 33. the first limiting baffle piece; 34. the second limiting baffle piece; 35. a first seal ring; 36. and a second sealing ring.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

Referring to fig. 1 to 4, fig. 1 shows a schematic structural view of a medical grinding tool according to an embodiment of the present application. Fig. 2 shows an enlarged schematic view of the structure of fig. 1 at a. Fig. 3 shows an enlarged schematic view of the structure of fig. 1 at B. Fig. 4 shows a schematic structural view of the inner cutter assembly 10 of the medical grinding cutter according to an embodiment of the present application. An embodiment of the present application provides an inner cutter assembly 10 of a medical grinding cutter, the inner cutter assembly 10 of the medical grinding cutter includes: an inner cutter 11, a wire 12 and a first heat shrink sleeve 13. One end of the wire 12 is connected with the inner cutter 11, the other end of the wire 12 is connected with the transmission assembly 30, and the wire 12 is provided with a bending part 121. The first heat shrink sleeve 13 is sleeved outside the bending part 121.

The inner cutter assembly 10 of the medical grinding cutter has the advantages that when the inner cutter assembly 10 works, the transmission assembly 30 drives the metal wire 12 to rotate, the metal wire 12 drives the inner cutter head 11 to rotate, and the grinding operation on bone tissues is realized in the rotation process of the inner cutter head 11. When the bending portion 121 breaks due to stress concentration, since the first heat shrinkage sleeve 13 is sleeved outside the bending portion, the inner cutter 11 can be prevented from falling into the body, thereby improving working efficiency and safety.

Optionally, the wire 12 includes, but is not limited to being provided as a steel wire or copper wire, or the like. The diameter size of the metal wire 12 is flexibly adjusted and set according to actual requirements, and based on the flexible characteristics of the metal wire 12, the hardness of the metal wire 12 can be correspondingly adjusted by adjusting the diameter size of the metal wire 12. Specifically, as the diameter size of the wire 12 increases, the hardness of the wire 12 increases; conversely, as the diameter of the wire 12 decreases in size, the stiffness of the wire 12 decreases.

The flexible nature of the wire 12, among other things, and the particular stiffness requirements, enables high speed rotational output torque in the curved outer cutter assembly 20 without breaking.

Referring to fig. 2 and 4, in one embodiment, the first heat shrinkable sleeve 13 is a wear-resistant and self-lubricating heat shrinkable sleeve. In this way, when the first heat shrinkage bush 13 is in contact with the outer cutter assembly 20 sleeved outside thereof, friction with the outer cutter assembly 20 can be reduced, thereby reducing scraps caused by friction and reducing heat.

Specifically, the first heat shrink sleeve 13 includes, but is not limited to, materials such as polyvinyl fluoride, polyvinylidene fluoride, and the like.

Referring to fig. 2 and 4, in one embodiment, the inner cutter assembly 10 of the medical milling cutter further includes a connecting sleeve 14. The inner cutter 11 includes a grinding head 111 and a shank 112 connected to the grinding head 111. The rod 112 extends into and is welded to the connection sleeve 14 from one end of the connection sleeve 14, and the wire 12 extends into and is welded to the connection sleeve 14 from the other end of the connection sleeve 14. In this way, compared with the mode of directly welding the rod 112 with the end of the wire 12, the welding area of the connecting sleeve 14 and the rod 112 is larger, and the welding area of the connecting sleeve 14 and the wire 12 is larger, so that the connecting sleeve 14, the rod 112 and the wire 12 can be firmly connected.

It should be noted that, the "grinding head 111" may be "a part of the stem 112", that is, the "grinding head 111" is integrally formed with "other parts of the stem 112"; or a separate component which is separable from the other part of the stem 112, namely, the grinding head 111 can be manufactured independently and then combined with the other part of the stem 112 into a whole.

Referring to fig. 2, a first step 1121 is disposed on an outer wall of the stem 112, and an end surface of the connecting sleeve 14 abuts against the first step 1121. In addition, a second step 141 is provided on the inner wall of the connecting sleeve 14, and the end surface of the rod 112 and the second step 141 are abutted against each other. Thus, the rod 112 and the connecting sleeve 14 are axially limited through the steps, and stability is improved.

Referring to fig. 2 and 4, in one embodiment, the connecting sleeve 14 is provided with at least one first welding hole (not shown) extending along an axis thereof. The first welding hole is disposed opposite to the outer wall of the stem 112. The connecting sleeve 14 is also provided with at least one second welding hole extending along its axis. The second welding hole is arranged opposite to the outer wall of the metal wire 12. Thus, the connecting sleeve 14 and the rod 112 can be welded and fixed through the first welding hole, and the welding seam is positioned in the first welding hole; likewise, the connection sleeve 14 and the wire 12 can be welded and fixed through the second welding hole, and the welding seam is positioned in the second welding hole.

Referring to fig. 2 and 4, in some embodiments, the first heat shrink sleeve 13 is further sleeved on the outer portion of the connecting sleeve 14, so as to prevent the connecting sleeve 14 and the outer cutter assembly 20 from contacting each other, thereby reducing friction between the connecting sleeve 14 and the outer cutter assembly 20, reducing chips caused by friction, and reducing heat.

Referring to fig. 1-3, in one embodiment, a medical milling cutter includes the inner cutter assembly 10 of any of the above embodiments, and further includes the outer cutter assembly 20 and the transmission assembly 30. The inner cutter assembly 10 is rotatably arranged in the outer cutter assembly 20, the other end of the metal wire 12 is connected with the transmission assembly 30, and the transmission assembly 30 is used for being connected with a power mechanism.

When the medical grinding cutter is in operation, the transmission assembly 30 drives the metal wire 12 to rotate, the metal wire 12 drives the inner cutter head 11 to rotate, and the grinding operation on bone tissues is realized in the rotation process of the inner cutter head 11. When the bending portion 121 breaks due to stress concentration, since the first heat shrinkage sleeve 13 is sleeved outside the bending portion, the inner cutter 11 can be prevented from falling into the body, thereby improving working efficiency and safety.

In addition, since the outer cutter assembly 20 and the inner cutter assembly 10 are bent, the operator can obtain a better view through the bending angle so as to observe the operation part, thereby improving the accuracy and success rate of the operation and bringing better treatment effect to the patient. In addition, in terms of surgical wounds, a larger working area is provided by the curved angle of the grater 111, which results in a smaller wound area for lesion removal by the curved angle grater 111 and a faster patient recovery period than by the straight grater 111 under the same conditions.

Referring to fig. 3 and 5, fig. 5 shows a schematic structural view of an outer cutter assembly 20 of a medical grinding cutter according to an embodiment of the present application. In one embodiment, the outer cutter assembly 20 includes a handle body 21, an outer cutter tube 22, and a first support sleeve 23. The handle 21 is provided with a channel 211, and the transmission assembly 30 is rotatably arranged in the channel 211. One end of the outer cutter tube 22 is connected with the handle body 21, and the other end of the outer cutter tube 22 is connected with the first supporting sleeve 23. The metal wire 12 is rotatably arranged in the outer cutter tube 22, and the inner cutter head 11 is rotatably arranged in the first supporting sleeve 23. Thus, the first supporting sleeve 23 plays a role in supporting and guiding the inner cutter head 11, and noise and vibration are reduced.

Alternatively, the outer cutter tube 22 is provided as a straight tube before assembly, and after the whole cutter is assembled, the bent shape is realized after bending treatment by a special tool.

Referring to fig. 3 and 6, fig. 6 is a schematic structural diagram of a transmission assembly 30 of a medical grinding tool according to an embodiment of the present application. In one embodiment, the transmission assembly 30 includes a transmission shaft 31, a bearing 32 rotatably disposed on the transmission shaft 31, and a first limit stop 33 abutting against one end surface of the bearing 32. The inner wall of the passage 211 is provided with a positioning flange 2111 which is in abutting engagement with the other end face of the bearing 32. The first limit stop 33 is connected to the inner wall of the channel 211. The wire 12 is fixedly connected to a drive shaft 31, which drive shaft 31 is also adapted to be connected to a power mechanism (not shown). Thus, when the power mechanism works, the transmission shaft 31 is driven to rotate, and under the supporting action of the bearing 32, the transmission shaft 31 stably runs and correspondingly drives the metal wire 12 to rotate around the central axis thereof. In addition, since the positioning flange 2111 and the first stopper 33 are respectively in abutting engagement with the opposite end surfaces of the bearing 32, the bearing 32 can be restrained from moving in the axial direction, and the position of the transmission assembly 30 inside the passage 211 can be restrained.

It should be noted that the "positioning flange 2111" may be "a part of the shank 21", that is, "the positioning flange 2111" is integrally formed with "other part of the shank 21"; or may be a separate component from the remainder of the shank 21, i.e., the locating flange 2111 may be manufactured separately and then integrated with the remainder of the shank 21.

Referring to fig. 7 and 8, fig. 7 is a schematic structural view of a medical grinding tool according to another embodiment of the present application. Fig. 8 shows an enlarged schematic view of the structure of fig. 7 at C. The number of the bearings 32 is at least two, and each bearing 32 is sleeved on the transmission shaft 31 in sequence along the axial direction of the transmission shaft 31. Thus, the stability of the transmission shaft 31 can be improved and the transmission shaft 31 is prevented from moving by providing at least two bearings 32.

Referring to fig. 8, in one embodiment, at least one drain hole 221 is formed on an outer wall of the outer cutter tube 22 near one end of the handle 21. The drain hole 221 communicates with a drain passage between the inner wall of the outer cutter tube 22 and the outer wall of the wire 12. Thus, after the tissues and the waste liquid enter the liquid discharge channel, the tissues and the waste liquid can be discharged from the liquid discharge hole; alternatively, the drain hole 221 may be connected to an external negative pressure suction device, and the drain hole 221 will drain out under the suction force of the negative pressure suction device; the liquid can be prevented from entering the inside of the handle body through the liquid discharge hole 221, and further, the liquid can be prevented from flowing backwards along the axial direction of the transmission shaft 31, so that the liquid can be prevented from flowing outwards through the handle body 21, and the liquid can be prevented from entering the inside of the motor of the power mechanism to cause the motor to be damaged.

Referring to fig. 3 and 6, in one embodiment, two second limiting stoppers 34 are disposed on the transmission shaft 31. The two second limiting stoppers 34 are located at two opposite sides of the bearing 32 and respectively butt against two opposite end surfaces of the bearing 32. Thus, the two second limiting stoppers 34 can limit and fix the bearing 32 on the transmission shaft 31.

Referring to fig. 3 and 6, in one embodiment, one of the second limiting blocks 34 is, for example, a protruding edge wound on an outer wall of the transmission shaft 31, and the other second limiting block 34 is, for example, detachably connected to the transmission shaft 31, so as to facilitate the disassembly and assembly of the bearing 32 on the transmission shaft 31.

Referring to fig. 3 and 6, in one embodiment, the transmission assembly 30 further includes a first sealing ring 35 disposed between the outer wall of the transmission shaft 31 and the inner wall of the bearing 32, and a second sealing ring 36 disposed between the outer wall of the bearing 32 and the inner wall of the channel 211. The transmission shaft 31 is provided with a shaft hole 311, and the metal wire 12 is arranged in the shaft hole 311 in a penetrating manner and is connected with the transmission shaft 31 in a welding manner. In this way, under the sealing action of the first sealing ring 35 and the second sealing ring 36, and the welding mode of the metal wire 12 and the transmission shaft 31, the shaft hole 311 is sealed, so that the sealing action is better, and the body fluid is prevented from flowing outwards through the handle body 21.

Referring to fig. 3 and 6, in one embodiment, for ease of assembly, the handle 21 includes two split shells 212 that are removably connected and coaxially disposed. The first limiting stopper 33 is, for example, clamped and fixed between the two split shells 212, and the specific form of the first limiting stopper 33 is, for example, a limiting piece, which can be clamped and fixed conveniently. Alternatively, the two split shells 212 include, but are not limited to, being threadably connected, or being snap-fit connected, or being otherwise connected.

Referring to fig. 3-5, in one embodiment, the outer cutter assembly 20 further includes a second support sleeve 24. The second supporting sleeve 24 is connected with the handle body 21, and the outer cutter tube 22 is arranged in the second supporting sleeve 24 in a penetrating way. In this way, the second supporting sleeve 24 plays a role in supporting the outer cutter tube 22, so that the rigidity of the connecting part of the outer cutter tube 22 and the handle body 21 is improved, and the fracture defect caused by stress concentration is avoided.

Referring to fig. 1 and 2, in one embodiment, the outer cutter assembly 20 further includes an elastic layer 25. The elastic layer 25 is wrapped on the outer wall of the outer cutter tube 22. In this manner, vibrations transmitted by grater 111 to the wound portion of the patient during operation can be reduced.

Referring to fig. 3-5, in one embodiment, the outer cutter assembly 20 further includes a retaining sleeve 26. The fixing sleeve 26 is injection molded integrally with the shank 21, for example. Alternatively, the outer cutter tube 22 is inserted into the fixing sleeve 26 and welded to the fixing sleeve 26. Likewise, the second support sleeve 24 is welded, for example, to the fixing sleeve 26.

Referring to fig. 3-5, in one embodiment, the outer cutter assembly 20 further includes a third support sleeve 27 disposed within the stationary sleeve 26. The third support sleeve 27 is fixed inside the fixed sleeve 26, for example by welding. The wire 12 is rotatably threaded in the third support sleeve 27. In this way, the third supporting sleeve 27 plays a role in supporting and guiding the wire 12, can reduce stress concentration of the wire 12, prevent failure, reduce the wire 12 from moving, and reduce the heat generation amount, thereby improving the service life of the wire 12. In addition, the third support sleeve 27 can act as a barrier to liquid, which is advantageous for improving the sealing.

Referring to fig. 3, in one embodiment, the inner cutter assembly 10 further includes a second heat shrink 15. The second heat shrink sleeve 15 is sleeved on one end of the metal wire 12 far away from the inner cutter head 11 and is arranged inside the third supporting sleeve 27. Specifically, the second heat shrink sleeve 15 includes, but is not limited to, a heat shrink sleeve that is wear resistant and self-lubricating, can reduce friction with the third support sleeve 27, thereby reducing debris caused by friction, and can reduce heat.

In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms refer to the orientation or positional relationship based on the drawings, which are merely for convenience of description and simplification of description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In this application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the claims. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims (10)

1. An inner blade assembly for a medical grinding tool, the inner blade assembly comprising:

an inner cutter head;

one end of the metal wire is connected with the inner cutter head, the other end of the metal wire is connected with the transmission assembly, and the metal wire is provided with a bending part; and

the first heat shrinkage sleeve is sleeved outside the bending part.

2. The inner cutter assembly of the medical milling cutter according to claim 1, wherein the inner cutter assembly of the medical milling cutter further comprises a connecting sleeve; the inner cutter head comprises a grinding head and a rod part connected with the grinding head; the rod part extends into one end of the connecting sleeve and is connected with the connecting sleeve in a welding way, and the metal wire extends into the other end of the connecting sleeve and is connected with the connecting sleeve in a welding way.

3. The inner cutter assembly of the medical grinding cutter according to claim 2, wherein a first step is arranged on the outer wall of the rod part, and the end face of the connecting sleeve is mutually abutted with the first step; the inner wall of the connecting sleeve is provided with a second step, and the end face of the rod part is mutually abutted with the second step.

4. The inner cutter assembly of the medical grinding cutter according to claim 2, wherein the connecting sleeve is provided with at least one first welding hole extending along the axis of the connecting sleeve, and the first welding hole is opposite to the outer wall of the rod part; and the connecting sleeve is also provided with at least one second welding hole extending along the axis of the connecting sleeve, and the second welding hole is opposite to the outer wall of the metal wire.

5. A medical grinding tool, characterized in that the medical grinding tool comprises an inner cutter assembly according to any one of claims 1 to 4, an outer cutter assembly and a transmission assembly, wherein the inner cutter assembly is rotatably arranged in the outer cutter assembly in a penetrating manner, the other end of the metal wire is connected with the transmission assembly, and the transmission assembly is used for being connected with a power mechanism.

6. The medical milling cutter of claim 5, wherein the outer cutter assembly comprises a handle body, an outer cutter tube, and a first support sleeve; the handle body is provided with a channel, and the transmission assembly is rotatably arranged in the channel in a penetrating way; one end of the outer cutter tube is connected with the handle body, and the other end of the outer cutter tube is connected with the first supporting sleeve; the metal wire is rotatably arranged in the outer cutter tube in a penetrating mode, and the inner cutter head is rotatably arranged in the first supporting sleeve in a penetrating mode.

7. The medical grinding tool according to claim 6, wherein the transmission assembly comprises a transmission shaft, a bearing rotatably arranged on the transmission shaft and a first limiting stop piece in mutually abutting fit with one end face of the bearing, a positioning flange in mutually abutting fit with the other end face of the bearing is arranged on the inner wall of the channel, and the first limiting stop piece is connected with the inner wall of the channel; the metal wire is fixedly connected with the transmission shaft, and the transmission shaft is also used for being connected with the power mechanism.

8. The medical milling cutter of claim 7, wherein the drive assembly further comprises a first seal ring disposed between the drive shaft outer wall and the bearing inner wall and a second seal ring disposed between the bearing outer wall and the channel inner wall; the transmission shaft is provided with a shaft hole, and the metal wire penetrates through the shaft hole and is connected with the transmission shaft in a welding mode.

9. The medical grinding tool according to claim 7, wherein the number of the bearings is at least two, and each bearing is sequentially sleeved on the transmission shaft along the axial direction of the transmission shaft.

10. The medical milling cutter according to any one of claims 6 to 9, wherein at least one drain hole is provided in an outer wall of the outer cutter tube near an end of the shank body, the drain hole being in communication with a drain passage between an inner wall of the outer cutter tube and an outer wall of the wire.