Grinding device

Abstract

The utility model discloses a grinding device which comprises a handle body and a grinding piece, the handle body comprises a mounting shell and a clamping body, a mounting cavity and a connecting hole are formed in the mounting shell, the connecting hole is communicated with the mounting cavity, and the clamping body is mounted in the mounting cavity; the grinding piece comprises a grinding part and a rod part which are connected with each other, the rod part comprises a clamping section and a connecting section, and the connecting section is located between the grinding part and the clamping section; wherein the clamping section is provided with a first position clamped together with the clamping body and a second position separated from the clamping body, when the clamping section is located at the first position, at least part of the connecting section is located in the connecting hole, and the area of the cross section of the clamping section is smaller than that of the cross section of the connecting section in the radial direction of the connecting hole. The utility model solves the problem that the grinding head is difficult to pull out from the grinding device because the rod part of the grinding head is easy to deform when the motor is instantly braked under the protection program of the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a grinding device. BACKGROUND

[0002] The medical grinding device is a device for polishing, planing, boring and other operations on surgical sites (such as spine, bone, etc.) by clamping different grinding heads. The grinding device usually includes a clamping component for clamping the grinding head and a power component installed in the inner cavity of the handle, etc., and the power component can drive the grinding head clamped by the clamping component to rotate at high speed. In the actual use process, when the operator exerts too much force, the motor of the power component is overloaded, and the rod part of the grinding head is easily deformed when the motor produces instantaneous braking under its own protection program, thereby making it difficult to pull out the grinding head from the grinding device. CONTENT OF THE UTILITY MODEL

[0003] The main purpose of the present application is to provide a grinding device to solve the problem that the rod part of the grinding head is easily deformed when the motor produces instantaneous braking under its own protection program in the background technology, thereby making it difficult to pull out the grinding head from the grinding device.

[0004] According to one aspect of the present application, a grinding device is provided, comprising:

[0005] A handle body, the handle body comprising a mounting shell and a clamping body, the mounting shell being provided with a mounting cavity and a connecting hole, the connecting hole being in communication with the mounting cavity, and the clamping body being installed in the mounting cavity;

[0006] A grinding member, the grinding member comprising a grinding part and a rod part connected to each other, the rod part comprising a clamping section and a connecting section, the connecting section being located between the grinding part and the clamping section;

[0007] Wherein, the clamping section has a first position clamped together with the clamping body and a second position separated from the clamping body, the connecting section is at least partially located in the connecting hole when the clamping section is located at the first position, along the radial direction of the connecting hole, the cross-sectional area of the clamping section is smaller than the cross-sectional area of the connecting section.

[0008] Further, along the axial direction of the connecting hole, the projection outer contour of the clamping section is located within the projection outer contour of the connecting section.

[0009] Further, the cross sections of the clamping section and the connecting section are both circular, the diameter of the clamping section is R1, the diameter of the connecting section is R2, and the difference between R2 and R1 is not less than 0.02mm.

[0010] Further, the difference between R2 and R1 is also not greater than 0.05 mm.

[0011] Further, the value of R1 is not less than 2.32 mm and not greater than 2.34 mm.

[0012] Further, the value of R2 is not less than 2.36 mm and not greater than 2.37 mm.

[0013] Further, the length of the clamping section is not less than 29.5 mm and not greater than 30.5 mm along the axial direction of the rod portion.

[0014] Further, the surface roughness of at least one of the clamping section and the connecting section is not greater than 0.8 um.

[0015] Further, the grinding portion comprises a grinding head and a transition section, the transition section is located between the grinding head and the connecting section, the cross section of the transition section along the radial direction of the connecting hole is circular, and the diameter of the transition section gradually decreases in the direction away from the connecting section along the axial direction of the transition section.

[0016] Further, the connecting hole comprises a first hole section and a second hole section, and the mounting shell comprises:

[0017] a main shell member, the mounting cavity is arranged in the main shell member;

[0018] an extension member, the extension member comprises a tube body and bearings, the inner hole of the bearing is the first hole section, the tube body is sleeved with the main shell member, the second hole section is arranged in the tube body and communicates with the mounting cavity, and the bearings are arranged in the tube body in the axial direction of the tube body.

[0019] wherein, the diameter of the first hole section is not greater than the diameter of the second hole section and communicates with the second hole section, and the fitting tolerance between the first hole section and the connecting section is not less than 0.005 mm; and / or,

[0020] the hardness of the clamping section and the connecting section is not less than 40HRC.

[0021] In this application, the grinding apparatus includes a handle body and a grinding component. The clamping body of the handle body is installed in the mounting cavity of the mounting housing. The rod of the grinding component includes a clamping section and a connecting section, with the connecting section located between the grinding component and the clamping section. Given that the clamping section, which is mainly held by the clamping body, is prone to deformation when the motor driving the grinding component to rotate experiences instantaneous braking, the cross-sectional area of ​​the clamping section in this application is smaller than that of the connecting section. Therefore, during the process where the connecting section pulls the clamping section to a second position separated from the clamping body, the deformation of the clamping body will be insufficient to cause it to be stuck in the connecting hole, thereby ensuring that the entire grinding component is completely removed from the handle body. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of a grinding device provided in an embodiment of the present invention;

[0024] Figure 2 for Figure 1 AA section view;

[0025] Figure 3 This is a schematic diagram of the structure of the grinding part;

[0026] Figure 4 for Figure 2 Enlarged diagram of part B.

[0027] The above figures include the following reference numerals:

[0028] 10. Mounting housing; 101. Mounting cavity; 102. Connecting hole; 11. Main housing component; 12. Tube body; 120. Second hole section; 121. Connecting seat; 122. First tube section; 123. Second tube section; 124. Third tube section; 125. Sleeve; 13. Bearing; 130. First hole section; 20. Clamping body; 21. Clamping hole; 22. Abutment; 30. Grinding part; 31. Grinding section; 311. Grinding head; 312. Transition section; 32. Rod part; 321. Clamping section; 322. Connecting section. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0031] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the present application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale of the actual proportions used in the fabrication, assembly, and operation of the example embodiments. Techniques, methods, and apparatus known to those of ordinary skill can not be discussed in detail herein, but should be considered as part of the description of the application. In all examples shown and discussed herein, any specific values are to be interpreted as merely exemplary and not limiting. Thus, other examples of example embodiments can have different values. It is noted that like numbers and letters refer to like elements throughout the several views of the drawings and, as such, no further discussion with regard thereto is deemed necessary.

[0032] In the process of grinding, planing, boring and other operations of the patient's affected area by the medical staff using the grinding device, individual medical staff use excessive force to use violence. In this process, the motor driving the grinding part 30 of the grinding device to rotate is prone to overload. At this time, the motor produces a transient brake under its own protection program, causing the rod part 32 of the grinding part 30 to deform, making it difficult to pull out the grinding part 30.

[0033] In view of the above problems, the inventor of the utility model has found through in-depth research that the section of the rod part 32 of the grinding piece 30 extending into the grinding device is usually clamped by a clamping body 20 of a clamping component installed in the grinding device, the clamping body 20 is provided with a clamping hole 21 on the side close to the grinding piece 30, a plurality of hole holes communicating with the clamping hole 21 are arranged in the hole wall of the clamping hole 21 and spaced apart in the circumferential direction of the clamping body 20, and an abutting piece 22 capable of reciprocating in the axial direction of the hole hole is arranged in the hole hole. The clamping component further comprises a sleeve, the sleeve is sleeved on the outside of the clamping body 20 and can be moved to abut against the abutting piece 22, so as to press the abutting piece 22 in the axial direction of the hole hole to a position abutting against the rod part 32 of the grinding piece 30 in the clamping hole 21, thereby realizing stable and firm clamping of the rod part 32 in the clamping hole 21, and achieving high-speed rotation of the grinding piece 30 driven by the clamping body 20 connected with the output shaft of the motor. When the medical staff uses the motor violently and causes the motor to overload and brake, the force generated causes the part of the rod part 32 abutted by the abutting piece 22 to deform, and the rod part 32 will pass through the connecting hole 102 matched with the rod part 32, such as a local protrusion, a bulge, etc., during the process of pulling out of the clamping hole 21, although the deformation amount is limited by the clamping hole 21 and will not be too large, but such deformation still causes the deformed part of the rod part 32 to be easily clamped in the connecting hole 102 and unable to be pulled out.

[0034] To this end, the utility model embodiment provides a grinding device, the rod part 32 of the grinding piece 30 of the grinding device can be smoothly pulled out from the grinding device even if deformation is caused by violent use. Figures 1 to 4 The grinding device comprises a handle main body and a grinding piece 30. The handle main body comprises a mounting shell 10 and a clamping body 20. As shown in Figure 2 , the mounting shell 10 is provided with a mounting cavity 101 and a connecting hole 102, and the connecting hole 102 communicates with the mounting cavity 101. The clamping body 20 is installed in the mounting cavity 101. The grinding piece 30 comprises a grinding part 31 and a rod part 32 connected with each other. As shown in Figure 3 and Figure 4 , the rod part 32 comprises a clamping section 321 and a connecting section 322, and the connecting section 322 is located between the grinding part 31 and the clamping section 321.

[0035] The clamping section 321 has a first position clamped with the clamping body 20 and a second position separated from the clamping body 20. When the clamping section 321 is in the first position, the connecting section 322 is at least partially located in the connecting hole 102. In the radial direction of the connecting hole 102, the cross-sectional area of the clamping section 321 is smaller than that of the connecting section 322. Thus, even if the clamping section 321 is deformed, such as partially protruding, bulging, etc., at the position clamped by the clamping body 20, the clamping section 321 can still be smoothly pulled out along the connecting hole 102. Moreover, the difficulty in processing the rod portion 32 is reduced, and the clamping body 20 only needs to clamp a slightly thinner section of the rod portion 32.

[0036] As can be seen, in the embodiment, the grinding device includes a handle body and the grinding member 30. The clamping body 20 of the handle body is installed in the installation cavity 101 of the installation housing 10, and the rod portion 32 of the grinding member 30 includes the clamping section 321 and the connecting section 322. The connecting section 322 is located between the grinding portion 31 and the clamping section 321. When the motor driving the grinding member 30 to rotate is instantaneously braked, the clamping section 321 clamped by the clamping body 20 is prone to deformation. In this embodiment, the cross-sectional area of the clamping section 321 is smaller than that of the connecting section 322. During the process of pulling the clamping section 321 by the connecting section 322 to move to the second position separated from the clamping body 20, the deformation of the clamping body 20 is insufficient to cause the clamping body 20 to be stuck in the connecting hole 102, thereby ensuring that the entire grinding member 30 can be completely pulled out of the handle body.

[0037] In the axial direction of the connecting hole 102, the projection outer contour of the clamping section 321 is located in the projection outer contour of the connecting section 322. Thus, the clamping section 321 is prevented from being excessively pulled out due to partially protruding from the surface of the connecting section 322 in the radial direction of the connecting hole 102. Moreover, when the clamping section 321 is deformed at the position clamped by the abutting member 22, the deformation is located between the projection outer contour of the clamping section 321 and the projection outer contour of the connecting section 322, thereby further preventing the deformation from causing the pulling-out difficulty problem.

[0038] The cross sections of the clamping section 321 and the connecting section 322 in the embodiment are circular, as shown in FIG. 3. Figure 3As shown, the diameter of the clamping section 321 is R1, the diameter of the connecting section 322 is R2, and the difference between R2 and R1 is not less than 0.02 mm, i.e. R2-R1≥0.02 mm. In this way, by making the diameter of the clamping section 321 at least 0.02 mm smaller than the diameter of the connecting section 322, it is ensured that the rod portion 32 of the grinding piece 30 can still be smoothly pulled out of the handle body after the clamping section 321 is deformed. Specifically, the difference between R2 and R1 in the present embodiment can include one of 0.02 mm, 0.021 mm, 0.022 mm, 0.023 mm, 0.024 mm, 0.025 mm, 0.026 mm, 0.027 mm, 0.028 mm, 0.029 mm, 0.03 mm, etc.

[0039] Secondly, the difference between R2 and R1 in the present embodiment is also not greater than 0.05 mm, i.e. R2-R1≤0.05 mm, so as to avoid reducing the connection strength of the connecting portion on the side close to each other of the clamping section 321 and the connecting section 322 due to the difference being too large. The difference between R2 and R1 can specifically include one of 0.02 mm, 0.021 mm, 0.022 mm, 0.023 mm, 0.024 mm, 0.025 mm, 0.026 mm, 0.027 mm, 0.028 mm, 0.029 mm, 0.03 mm, 0.032 mm, 0.033 mm, 0.034 mm, 0.036 mm, 0.038 mm, 0.04 mm, 0.041 mm, 0.043 mm, 0.045 mm, 0.046 mm, 0.048 mm, 0.049 mm, 0.05 mm, etc.

[0040] In the present embodiment, the diameter R1 of the clamping section 321 is not less than 2.32 mm and not greater than 2.34 mm. By making the diameter of the clamping section 321 within this range of values, it is ensured that the clamping section 321 can be stably and firmly clamped by the clamping body 20 while ensuring the structural rigidity of the clamping section 321, so that the clamping section 321 will not be broken under high-speed operation, thereby enabling the clamping section 321 to stably and reliably drive the grinding portion 31 away from the clamping section 321 of the connecting section 322, improving the service life of the grinding piece 30 and the working stability of the entire grinding device. The value of R1 can include one of 2.32 mm, 2.321 mm, 2.324 mm, 2.326 mm, 2.328 mm, 2.33 mm, 2.331 mm, 2.332 mm, 2.334 mm, 2.335 mm, 2.337 mm, 2.338 mm, 2.34 mm, etc.

[0041] In this embodiment, the diameter R2 of the connecting segment 322 is not less than 2.36 mm and not greater than 2.37 mm, so that the structural rigidity of the connecting segment 322 can meet the working environment of the grinding part 30 at high speed and repeated operation, and ensure the overall structural strength of the grinding part 30. The specific value of R2 may include one of 2.36 mm, 2.361 mm, 2.362 mm, 2.363 mm, 2.364 mm, 2.365 mm, 2.366 mm, 2.367 mm, 2.368 mm, 2.369 mm, 2.37 mm, etc.

[0042] Along the axial direction of the rod 32, the length of the clamping section 321 (this length is) Figure 3 The length (indicated by L1) shall be no less than 29.5 mm and no more than 30.5 mm, so that the length of the clamping section 321 engaging with the clamping body 20 is neither too short, which would reduce clamping stability, nor too long, which would reduce the overall structural rigidity of the grinding workpiece 30. The length of the clamping section 321 may include one of the following: 29.5 mm, 29.6 mm, 29.7 mm, 29.8 mm, 29.9 mm, 30.0 mm, 30.1 mm, 30.2 mm, 30.3 mm, 30.4 mm, or 30.5 mm.

[0043] In addition, when the surface roughness of the rod portion 32 is large, the friction between the clamping section 321 and the handle body is also large in the state that the clamping section 321 is clamped (for example, the friction between the clamping section 321 and the inner wall surface of the clamping hole 21 and the connecting hole 102 is large, and the friction between the connecting section 322 and the inner wall surface of the connecting hole 102 is also large), which also increases the possibility that the rod portion 32 is stuck in the handle body. In this embodiment, the surface roughness of at least one of the clamping section 321 and the connecting section 322 is not greater than 0.8 um (um is the unit of microns), and preferably the surface roughness of both the clamping section 321 and the connecting section 322 is not greater than 0.8 um. Thus, the difficulty of pulling out the clamping section 321 and the connecting section 322 due to the large surface roughness of the clamping section 321 and the connecting section 322 is avoided, the surface of the clamping section 321 and the connecting section 322 is smooth, the smooth surface can reduce the friction between the clamping section 321 and the clamping hole 21 and the connecting hole 102, and the friction between the connecting section 322 and the connecting hole 102, so that the process of taking out the grinding piece 30 is more smooth and labor-saving. The surface roughness of both the clamping section 321 and the connecting section 322 can include one of 0.8 um, 0.78 um, 0.75 um, 0.73 um, 0.7 um, 0.68 um, 0.65 um, 0.64 um, 0.62 um, 0.6 um, 0.57 um, 0.55 um, 0.5 um, etc., and can also be any other value not greater than 0.8 um, which is not limited in this embodiment.

[0044] The grinding portion 31 in this embodiment includes a grinding head 311 and a transition section 312, the transition section 312 is located between the grinding head 311 and the connecting section 322, the cross section of the transition section 312 along the radial direction of the connecting hole 102 is circular, and the diameter of the transition section 312 gradually decreases in the axial direction of the transition section 312 away from the connecting section 322. The transition section 312 can provide better coaxiality for the grinding head 311 and the rod portion 32, reduce the processing difficulty of the grinding head 311, reduce the vibration and imbalance of the grinding head 311, and improve the grinding accuracy of the grinding head 311 on the affected area. The grinding head 311 can be a spherical structure. In the radial direction of the transition section 312, the amplitude of the deviation of the grinding head 311 from the axis of the connecting section 322 due to runout is not greater than 0.025 mm, thereby improving the stability of the grinding head 311 during operation, and further improving the working stability of the entire grinding piece 30 and the grinding accuracy. The amplitude of the runout of the grinding head 311 can include one of 0.025 mm, 0.024 mm, 0.023 mm, 0.022 mm, 0.021 mm, 0.02 mm, etc.

[0045] In the embodiment, along the axial direction of the rod portion 32, the distance (as shown in Figure 3 indicated by the length L2) between the vertex of the end of the grinding head 311 away from the transition section 312 and the vertex of the end of the clamping section 321 away from the transition section 312 is not less than 109.5 mm and not more than 111 mm. The distance L2 can specifically include one of 109.5 mm, 109.6 mm, 109.7 mm, 109.8 mm, 109.9 mm, 110.0 mm, 110.1 mm, 110.4 mm, 110.6 mm, 110.8 mm, 111 mm, etc.

[0046] The connecting hole 102 in the embodiment includes a first hole section 130 and a second hole section 120. The mounting shell 10 includes a main shell component 11 and an extension component, and the mounting cavity 101 is arranged in the main shell component 11. The extension component includes a tube body 12 and bearings 13, and the inner holes of the bearings 13 are the first hole section 130. The tube body 12 is sleeved with the main shell component 11, the second hole section 120 is arranged in the tube body 12 in a penetrating manner and communicates with the mounting cavity 101, and the bearings 13 are at least two and are arranged in the tube body 12 in a spaced manner along the axial direction of the tube body 12. The at least two bearings 13 can improve the stability of the connecting section 322 during operation and avoid shaking of the connecting section 322. Among them, along the radial direction of the bearing 13, the diameter of the first hole section 130 is not greater than the diameter of the second hole section 120 and communicates with the second hole section 120, and the fit tolerance between the first hole section 130 and the connecting section 322 is not less than 0.005 mm. That is, the fit tolerance between the first hole section 130 and the connecting section 322 can include one of 0.005 mm, 0.0049 mm, 0.0048 mm, 0.0047 mm, etc., and the fit tolerance is preferably 0.005 mm. The fit tolerance refers to the sum of the tolerances of the first hole section 130 and the connecting section 322, which is the variation of the gap or interference between the first hole section 130 and the connecting section 322. In the embodiment, by making the fit tolerance between the first hole section 130 and the connecting section 322 not less than 0.005 mm, it is ensured that the connecting section 322 can drive the grinding head 311 to stably operate under the driving of the clamping section 321, and the machining difficulty of the clamping section 321 is not increased due to the too small fit tolerance, and the clamping section 321 can be smoothly pulled out of the first hole section 130 and the second hole section 120 when the clamping section 321 is deformed.

[0047] Please refer to Figure 4The pipe body 12 in the embodiment can include a connecting seat 121, a first pipe segment 122, a second pipe segment 123, a third pipe segment 124, and a sleeve 125. The connecting seat 121 is sleeved with the main shell part 11, and the size of the connecting seat 121 close to one end of the main shell part 11 is greater than the size of the connecting seat 121 away from one end of the main shell part 11. The first pipe segment 122 is connected between the end of the connecting seat 121 away from the main shell part and one of the bearings 13. The second pipe segment 123 is connected between the bearings 13 and the other bearing 13. The third pipe segment 124 is connected to the side of the other bearing 13 away from the second pipe segment 123. The sleeve 125 is sleeved outside the connecting seat 121 close to the first pipe segment 122, the first pipe segment 122, the second pipe segment 123, and the third pipe segment 124, to stably and firmly sleeve the connecting seat 121, the first pipe segment 122, the second pipe segment 123, and the third pipe segment 124 together, so that the overall structure of the pipe body 12 is stable and reliable, and the assembly between the pipe body 12 and the bearings 13 is more convenient and efficient. The second hole segment 120 is arranged through the connecting seat 121, the first pipe segment 122, the second pipe segment 123, and the third pipe segment 124.

[0048] In addition, the hardness of the clamping segment 321 and the connecting segment 322 in the embodiment is not less than 40HRC (HRC indicates that the hardness value is Rockwell hardness). In the embodiment, the hardness of the clamping segment 321 is not less than 40HRC, so that the clamping segment 321 is not easy to deform during the process of the motor overload brake, thereby ensuring that the grinding piece 30 can smoothly pull out the handle body. The hardness of the connecting segment 322 is not less than 40HRC, so as to improve the structural strength of the connecting segment 322. The hardness of the clamping segment 321 and the connecting segment 322 in the embodiment can include one of 40HRC, 41HRC, 42HRC, 43HRC, 44HRC, 45HRC, 46HRC, etc.

Claims

1. A grinding device, characterized by, The utility model relates to a handle body, the handle body includes installation casing (10) and clamping body (20), be provided with installation cavity (101) and connecting hole (102) in installation casing (10), connecting hole (102) with installation cavity (101) intercommunication, clamping body (20) is installed in installation cavity (101); Grinding piece (30), grinding piece (30) include each other connection grinding part (31) and stem part (32), stem part (32) include clamping section (321) and connecting section (322), connecting section (322) is located between grinding part (31) and clamping section (321); Wherein, the clamping section (321) has a first position and a second position separated from the clamping body (20), the clamping section (321) is located in the first position, the connecting section (322) is at least partially located in the connecting hole (102), along the radial direction of the connecting hole (102), the cross-sectional area of the clamping section (321) is less than the cross-sectional area of the connecting section (322). Along the axial direction of the connecting hole (102), the projection outer contour of the clamping section (321) is located within the projection outer contour of the connecting section (322).

2. The grinding device according to claim 1, characterized in that The cross-section of the clamping section (321) and the connecting section (322) is circular, the diameter of the clamping section (321) is R1, the diameter of the connecting section (322) is R2, the difference between R2 and R1 is not less than 0.02mm.

3. The grinding device of claim 1, wherein The difference between R2 and R1 is also not more than 0.05mm.

4. The grinding device of claim 3, wherein The value of R1 is not less than 2.32mm and not more than 2.34mm.

5. The grinding device of claim 3, wherein The value of R2 is not less than 2.36mm and not more than 2.37mm.

6. The grinding device of claim 3, wherein Along the axial direction of the stem part (32), the length of the clamping section (321) is not less than 29.5mm and not more than 30.5mm.

7. The grinding device according to any one of claims 1 to 6, characterized in that The surface roughness of at least one of the clamping section (321) and the connecting section (322) is not more than 0.8um.

8. The grinding device according to any one of claims 1 to 6, characterized in that The grinding part (31) includes a grinding head (311) and a transition section (312), the transition section (312) is located between the grinding head (311) and the connecting section (322), the cross-section of the transition section (312) is circular along the radial direction of the connecting hole (102), and the diameter of the transition section (312) gradually decreases in the direction away from the connecting section (322) along the axial direction of the transition section (312).

9. The grinding device according to any one of claims 1 to 6, characterized in that The connecting hole (102) includes a first hole section (130) and a second hole section (120), and the installation casing (10) includes:

10. The grinding device according to any one of claims 1 to 6, characterized in that A main shell component (11), the installation cavity (101) is provided in the main shell component (11); ​ The extension component comprises a tube body (12) and a bearing (13), an inner hole of the bearing (13) is the first hole section (130), the tube body (12) is sleeved with the main shell component (11), the second hole section (120) is arranged in the tube body (12) and communicates with the mounting cavity (101), the bearing (13) comprises at least two, at least two bearings (13) are arranged in the tube body (12) in the axial direction of the tube body (12); Wherein, the diameter of the first hole section (130) is not greater than the diameter of the second hole section (120) and communicates with the second hole section (120), and the cooperation tolerance between the first hole section (130) and the connecting section (322) is not less than 0.005mm; and / or, The hardness of the clamping section (321) and the connecting section (322) is not less than 40HRC.

Images